WWDC2003 Session 426

Transcript

Kind: captions Language: en this is one of the technologies that we've got an apple that I think has has tremendous potential and there but a lot of developers that are already taking advantage of Sherlock channels today particularly on internets and within corporations to deliver internal web services to their customers and there's some really cool Sherlock channels that have appeared from third parties but that you probably played with and so this is a great we think Sherlock channels and people are finding that Sherlock channels are a great way to actually get on to them onto Mac os10 if they have an evil if they don't know cocoa or carbon in fact if they can use their expertise in JavaScript and XML they can get onto the platform and take advantage of some technology that's their deliver some services on Mac OS 10 without having to write a fully native app but certainly one advantage people have seen and there's lots of others that we'll get into in this session so I'd like to invite Wayne lupfer all on stage and he's going to talk you through specifics Wayne runs the engineering team that's responsible for Sherlock channel thanks and welcome to the last of the Internet technology sessions delivering web services using sherlock channels so in this session we're going to talk about how to deliver web services using sherlock channels and i will talk about well what our web services when is using a channel to implement web services a good idea how to get started and some of the new things that we've provided in camper so what you learn is first what's new in Sherlock the application some of the developer opportunities the structure of a sherlock channel and then some of the details about how to develop a channel as well as some of the new features for sherlock channel developers and then we'll get into some advanced topics so first what's new in Sherlock the application well so when we thought about doing a new version of Sherlock for Panther we wanted to do three things we wanted to enhance the existing channels we wanted to improve the performance and we also wanted to provide a solution for the channel management problem so in particular with channels we one of the channels that we put a lot of effort into is the Yellow Pages channel and we've had some requests to add white pages which we've done and we've also added some additional features to the yellow pages themselves which we'll talk about in a bit for performance we rewrote the xquery engine from the ground up and made it two to three times faster in the Panther release as well as more conformance with the emerging excluded standard we've also made substantial improvements in launch time for the application as well as channel switching between channels as far as channel management is concerned there's been with all the third-party channels that have come out your toolbar gets pretty busy and it's often hard to find the channel that you're looking for so we've provided a solution to organize your channels that's patterned after the smart safari bookmarks in addition we found that folks were really interested in using a bunch of third-party channels but they didn't know where to find them and you had to kind of do a google search and now rummage around to try to find where they are so we decided to build the third-party channels directly into the application so first the phone book you'll notice that on the left side there's a little control to decide whether you're searching white pages or yellow pages but in addition we've had a lot of requests for category based searching if I want to search for Japanese restaurants I'm not really looking for a business that has Japanese restaurant in its name i'm really looking i would really like to be able to find retinoic a by category instead of just by business name so we support both in Panther the other requests we got a lot was being able to find nier not just a zip code or a city but also near a very specific address I'm going to this theater right I want to find the nearby restaurant and then we made printing from your phonebook easier as well with a one-button print the channels view is the solution to the channel management problem your toolbar just gets too crowded putting everything in the toolbar so we looked at the way Safari did bookmarks and we pattern to the Sherlock channel management view after the way safari bookmarks are done and this wise to control both what's in your toolbar what's in your channel menu as well as have direct access to all the channels that apple provides even those that are for other countries and we've added view for third-party channels and this is where we showcase all of your channels and make them easily available to users so they can they can find them dragon to the ones they like to the toolbar or even create their own collections it's also the place where the channel development tools show up so if you're a channel developer and you enable you enable the channel development tools you'll see them show up in the channels view so to demonstrate this I'd like to invite jessica con the channel and Sherlock channel development lead up welcome Jeff [Applause] so first we're going to show the phone book says you'll note on the left side there's a control for white pages and yellow pages right now we're in yellow pages mode the first field there is the business name or category field and if you notice as Jessica starts typing it automatically autocompletes to one of the categories in this case she typed restaurants and it auto completed after just a few characters and you'll note that in the pop-up we show maybe some variations on restaurants so you can choose a particular one for example say I want look for Indian food I choose Indian the next field over is the fine year katica field intellect before you can type zip codes and city names but the thing we've added is that it autocompletes city names so it has a database of cities and as you start to type it autocompletes and you'll see San Francisco with just a few characters the other thing it supports is it directly supports your address book and auto completion so for example if you want to find restaurants near a friend of yours you could type the name of the friend of yours in there or in this case we've added Moscone Center to our address book because he's been coming to moscone center a lot so we'd like to see what restaurants are near moscone center and as you see as Jessica types it autocompletes from the address book and then when you do the search you'll find Indian restaurants near the Moscone Center and driving directions to boot maybe walking direction so right so the other thing would like to show is the channel management view now we should be restoring the as you as noted there's a toolbar in a channels menu which allows you to control what's in the toolbar what from the channels menu we also provide access to all the Apple channels so if you decide you want to use some or others you can toss them from your toolbar and then decide later to go back and and put the lunch you're just stood in or if you'd like you could let's go back to the Apple channels right so what Jessica's done is added the Japanese news channel to the toolbar and if we decide we no longer want the Japanese news channel you can also remove from the toolbar just as easily you also note that at the bottom there there's a grouping called my channels now you can actually create as many of these as you like it's really a lot like the left column on iTunes where you can create your own music collections where you're creating collections with channel so let's say there are particular favorites I have I could select a number of channels and then drag them right to my channel and then that's provided a custom collection of the channels that I might like to use together and then finally and maybe the most importantly for the folks in this audience we've added other channels which is really where all of your channels shine it gives developed it gives customers direct access to all the creativity that's out there it provides a listing of the channel names as well as descriptions of each channel which you can customize in your channel on the web so these these channel there are two sources for this information one is the dmoz open source directory which is where we get an initial listing but also if you're interested in making sure that your channel shows up in this list you're welcome to submit your channel to Apple and we'll talk a bit about the submission process a little bit later so Thank You Jess let's go back to slides so Sherlock is web services for the rest of us but what our web services or maybe web services are soaked or.net or wsdl or uddi or any of a number of buzzwords but we don't think that's what web services are web services are airline reservations movie listings yellow pages translating things shopping finding things on the net that's really what web services are to a customer so what we try to do is deliver short deliver web services in a way that customers would like to see them but there are a number of challenges in doing this one is integration of information information can really come from many sources and so in order to present the user one unified view you'd really like to integrate it from a number of different places and you can do this in a web page however the traditional method of doing this on the web page is to create frames and to have some information in one frame and another information another frame but what we'd like to do instead is to bring this information together in a way that not just displays the information but really harness is it and allows you to interact interact with a unified interface rather than just seeing the information that's there so the other the other challenge is providing a user interface and on the web of course you can create fairly creative user interfaces but there are limits to it and what users really want is the native aqua user interface and so what Sherlock does is provide a native user the native user interface that users prefer in the context of the web service another challenge is change so you've let's say you deliver a web service as an application but your information source changes maybe maybe which you had to do in order to get certain information with the screen scrape a particular site well what happens is that site changes your application breaks you have to your you know your users are now out to lunch for a while until you give them a new version of the application so we have to be able to deal with change another challenge is security users aren't necessarily comfortable downloading a binary application on their disk they're very comfortable browsing web pages and following URLs because those provide a sandbox environment so you really also like something that has that capability easily you can get to it easily through a single link you'd like to be in a sandbox environment so excuse me gonna take drink so what Sherlock web services provide are a native user interface they're easy to create they provide sandbox security they also support changes on the web because they live on the web the Sherlock channel doesn't reside on your disk it resides on the web and so you need to make changes on the web it's reflected immediately additionally they integrate multiple sources of information so instead of just displaying bits of information from the web in one page they allow you to actually harness that information and do computation based on it maybe you look to take a city in state and look up a zip code and they use that zip code to query another side to get some information about what theaters are available and then you might use those theaters that theater lifts to query another side to find out what movies and showtimes are available and much like web pages they are accessible by a web link you can collect a single URL get a sherlock channel to come up much like applications you can put them in the dock you can actually save a shortcut to a sherlock channel put in your dock and in a single click you've open that web service and we've added a third party channels to sherlock to make them much more easy to find so one question is when do you want to create a channel versus say a web page or an application one way to think about it is that a channel is kind of somewhere in between the two so when you want something that's more than a web page you want more of a native user interface but you don't want something as complex as an application or that maybe to some users may be interpreted as having some risk of downloading it then you might want to choose a sherlock channel we're very very pleased with the number of third-party channels and the creativity out there and creating channels and I'd like to to demonstrate one of the the third party channels I'd like to invite kevin agren senior business development manager version tracker demo one please first of all thanks for having us out I'm here to talk about two reasons first one being why we chose to do a Sherlock channel second one being how it's going to benefit version tracker today and in the long haul we know right now that we have the world's biggest mac software database we're tracking over 30,000 applications but what we're seeing is that some users would rather view this offline or in a sherlock channel versus seeing this just on the version tracker site mostly what we feel that the clean interface is sherlock and the quick search function versus coming to a website especially if you're looking for multiple products the sherlock channels can offer you a much cleaner look the information you want right away and it's very accurate as well in our polls what we've seen is a lot of people now are coming over and using Sherlock is a primary user interface versus going through the web we also see that Apple put this in the dock and so strategically is a business to be part of Sherlock for version tracker is very important the channel development for us was almost as fluid as doing a web page because it's already built it's a simple XML feed so we're pulling content down right into it as far as the business benefits I'm just going to take a quick run here on the version tracker channel and so what you can see here that this is today's Mac software updates you can also easily do this by a search to go in for Sherlock you're going to pull up not only Apple Sherlock here but every other application that's going to be relevant to it as well to search this in Sherlock you're going to save time you're also going to be able to look at many applications versus what's going to be found in our database the important part is a business reversion trackers that were also a media company on top of building our own software applications a lot of our revenue comes from advertising dollars and when users decide to click up page they're going to come on diversion tracker and we're generating impression based ad revenue from every user that comes through here it's amazing to us but what we have seen now is that version tracker gets over 1 million searches per month through the Sherlock channel so it's a significant part of our business when users are in the search pages and it's deeper than the homepage it's a more educated user and advertisers right now see that this is a highly valuable position you've seen probably a couple hundred different advertisers come and go off the site but our revenue comes from the long haul companies like CDW they're believing in the mac user and spending money online with us definitely gives us time the money and the manpower app version tracker further develop our product version trekker pro and it also allows us to put your developers products out in front as many users as possible with Sherlock being in the DA conversion tracker being a channel it's very nice for us to increase our brand awareness to all mac users who not already where a version tracker when a right when a developer registers with us and they post their product we expect to get that out as quick as we can we also expect to get that out to as many people as possible so when you have the application posted here in our Sherlock channel what you're going to see is that as it's coming down the home page on version tracker it's picked up instantly in the Sherlock channel as well so for the developer your advantages you're also reaching these people through our Sherlock channel that weren't on version tracker as well one other thing that we can say about Sherlock is with more OS 10 users coming on board Mac users all the time when they use this learn about version tracker we're also seeing an increase in our sales for version tracker pro and the last thing is that the strategic positioning for version tracker in here is we really feel like we're the web is going is users want to interface with something like a sherlock channel so that they can come on make it part of their morning they're going to get on maybe look at their stock check the software applications that they care the most about and that's really all we have to say from version tracker thank you coming okay go back to five okay we can go back to slides so now I would like to take a survey how many folks out there have developed a sherlock channel already okay a few how many folks are thinking about maybe developing a sherlock channel quite quite a few quite a few great okay well you know this is really a developer opportunity as you saw it you can provide a more compelling user interface through a sherlock channel much more immediate right there you can update it on the web you can get to it from the web link from your website but also we built the channels right into sherlock so your user can see it either way and it's comfortable for users they can follow up link to get to it or they can simply select the channel from within sherlock and it provides better visibility for your web services than just having a website out in the sea of millions and millions of websites so if you'd like to develop a channel we've provided a number of tools built right into sherlock to help you do that there's actually a de bug menu in in sherlock that normally is invisible to most users but if you enable it you'll see a number of tools and we'll start to talk about those later so the first step is of course to develop your channel and that's what the bulk of this talk will be about but once you've done that you can submit your channel to Apple and the way you do that we got a menu item right there in the debug menu you just choose that item with your channel up front and you'll go right to a web page that allow you to to submit it to apple and then we'll add it in it'll be built right into Sherlock so let's talk a bit about how to create a sherlock channel and first i want to kind of give an overview of the structure of a sherlock channel to set us to set the stage for understanding the components and how they all fit together first we'll talk about some channel design principles briefly then we'll go into some detail about the key elements of a channel will give a demonstration of xquery which is a great XML processing technology that is under development by the w3c that we've adopted in Sherlock and we'll talk about some of the Sherlock extensions to that technology so first briefly the channel design principles one thing to think about is simply to focus on one topic searching version tracker is an example very specific purpose finding movies a very specific purpose another guideline if two it's great when your channel launches to have some information showing you'll note in the version tracker channel the moment the channel is opened it showed the latest updates on version tracker so the user didn't have to enter a query although they could but immediately they saw relevant information a third thing to consider is for performance reasons you really want to query the web only when necessary obviously on the internet that could be arbitrary delays and it's and for our modem users it can take a long time to download significant amounts of content so obviously there are times when you need to query the internet to get information but to keep that to a minimum cash stuff as much as possible which Sherlock arrives negative ones to let you do another guideline is to remember users safe if you go to a channel and use it to do a search let's say for movies in a particular zip code it's great if next time you go to that channel it knows the zip code that you entered last time so you don't have to re-enter it that's a basic guideline and of course follow the Aqua guidelines as with any application so now let's talk in some detail about what a chant what composes a channel and how it's made up the key elements of the channel are shown here at the top one being the user interface the data store below that and then trigger some services and we'll talk about each of those in turn so that's the user interface what's shown here is the user interface for the Yellow Pages channel but it's really tiny and hard to see so let me zoom in a little bit so now we're looking at the text entry field where you enter the category say like restaurants for the business name and you're seeing a little bit of the results down below that so this is the user interface the question is how do you make a user interface for Sherlock if you'd like to make a sherlock channel and the answer is really it the same as making it for an application you use interface builder it creates nib files the only difference is although it's like a nap in this respect it's not like a nap in that there's no objective-c code or c++ code or c code and its web resident unlike an application so how do we do this well we've added a palette inside interface builder that lets you name the UI elements in your user interface and you'll see later how that allows us to make the channel do what it needs to do without adding a lot of code so as an example on the phone book channel the main query field might be named phonebook query field and it's sort of like a path where dot is used as a separator and it can be arbitrarily deep the results down below might be called phonebook dot results and it of course have structure within that that would be accessed by adding dot more stuff so then there's the datastore now the data store is created at the time you run a channel so it's not something you have to put in your channel but it's created of the time you run and it contains all the data all the active data it contains temporary data that you're using at the moment it also contains persistent data and it also reflects the data that is contained in your you line it's a hierarchical structure made up of arrays and dictionaries arbitrarily deep and it's addressed by these dotted paths that I mentioned earlier items from the datastore can be created at any time for your own purpose and they're created as their referenced or it automatically when it when your channel runs directly reflects the contents of your you lie so you can access any value that's in your UI by simply reading a datastore path and that will tell you what the current value is if the user changes it you can be notified of that change and you can respond to it but if you read the value from the datastore entry it will always reflect the current value if you write to that value it's going to change the UI so if you decide you want to change the default on the text entry field you simply write a new string in there and then the UI changes it's a very powerful metaphor for quickly putting together a user interface the third area is triggers this is where you make things happen triggers one whenever a particular element of the data store changes and this may be an element that's tied to use your interface so if the user interface changes the trigger runs or it may be an element that say reflects data coming in from the web so the moment the data comes in a cure can run to respond to that data arriving a trigger can invoke services which we'll talk about at that or and then perhaps perform calculations based on the results of those calls and then change the UI so it's really the workforce one way to think about triggers and the JavaScript that you write in triggers is it's very much analogous to JavaScript on a web page you could think of the data store as being like the Dom of the web page and the triggers is being the the code that causes changes to happen in that DOM and last I'd like to talk about the services now these are the basic ways you get information from the web they're blended in xquery which is a powerful xml and HTML processing language and they let you query the web and face get a web page and extract the information you need from that web page where maybe you're querying a soap service and extracting the information you need from the XML that comes back it's also very good at constructing XML in order to use to send queries and processing the results so one example is you may create a service to given a city-state pair query the web and get back a list of theaters that are available in that particular city and state my package again as a service it then becomes one function call that the JavaScript trigger can call to get that information and the details of where it has to go to get the information how that hTML is processed perhaps or XML and how to extract the results is all hidden in the service so I want to say a little bit about xquery x cree is a new emerging language that is under development by the w3c and if you go to w3c org you can see the current spec it's really designed for processing XML it has a relationship with xslt and that both share xpath underneath so if you're familiar with those standards xquery would be pretty straightforward to pick up so now I'd like to invite just back up to demonstrate xquery and also the X Pathfinder channel so we go to demo monthly okay so just as open the ex Pathfinder channel now this is one of the channels that you'll get in the development tools which you can subscribe to directly from the debug menu it's really just a sherlock channel but it helps you in developing sherlock channel so at the top there you see a text field where you enter the URL so if we get the HTML from this website which is apple com you'll see down below it displays the content of the website and that's using a safari WebKit view and up above it shows you the structure of the HTML that is being fetched from that site so it's a proud of column browser and you'll see HTML the left and we go ahead and select HTML and drill downs you'll see the two things happen one as we start to see the tag better within that so we see head and body and we can click on body and go further but you'll also see that down below as we drill down and the content rendered below also changes so really what we're doing is we're assuming in through the content and seeing what portion of the HTML page we're seeing this is a much more convenient way of drilling down and finding the bit of information that you want to extract then staring at HTML and trying to figure it out down at the bottom you'll see there's an xquery town and this is the xquery code that is used to access what you see in the display below so if you want to get at that particular tab this is the xquery code that will do it and in fact it's an XPath path so let's go ahead and copy that out of the X Pathfinder channel and we'll switch over to the xquery channel the xquery channel is used for being able to execute and test out any sort of xquery it's a great way to learn xquery you know try something out get one and you'll you'll see the results let's go ahead and paste it in the xquery channel and if we can zoom in so we can maybe read it a little bit better so you'll see there what this xpath or xquery is doing is it's fetching the document it's looking at the HTML tag within it and then going into the body tag within that the center tag within that the table tag within that my TR tag within that and that's how we zoom in on the bit of data that we want but in fact this is a little bit fragile because if we change the order of what's happening in the web page this may no longer work and so one of the things that we want to be able to do is to make it more robust so the XPath channel is a great starting point to get you roughly where you want to be but then you probably want to massage the expression a little bit to make it more robust so justice you want I guess I'm taking over at this point so I'm going to zoom you back out so that i can type and change things without making you feel ill and basically what i'm going to do here is I'm going to append a bit of text which I will show you when I do min again but I'm adding a path that calls our source function and that's going to display the results of what we execute in this channel in a way that you can read basically when you actually keep something in xquery the data type that's returned by default is an XML tree and so you need to sometimes convert that into a human readable form if you want to play with it in the xquery channel so just to make this a little less fragile you would probably want to do something like you know take out HTML body and center add a slash in there if you guys know about X square if you take an X square your ex passed tutorial the double slash says I want all tables in this document but then we know we want the first table so we're just going to add in a bracelet says give me the first table so let me zoom well first I'll run this and then i'll zoom in and show you what I've done so basically this is giving you the same TR that we got in the expo finder channel and I'll zoom in here and you can see I've been able to remove three paths elements in my command and so that's basically three fewer things that can break the web page you're querying changes that's about it great thanks Jeff ok let's go back to slide so as you can see we've provided the tools to make it easy to get at the information you need to on the web and extract it for use in your channel we've also provided some extensions to both javascript which is used in triggers and xquery which is used in services to make it to make it easier to do different kinds of HTTP requests for example posts and dealing with cookies and headers and those sorts of things to deal with URL encoding and translation and to do data matching which is kind of a traditional Sherlock to way of extracting information so now I'd like to invite jessica back up to go into much more detail about how to actually develop a channel than nitty-gritty welcome just thank you hi everybody as Wayne said before I'm the channel development lead and I'm going to talk to you about how to actually get started with developing your channels please forgive me if I'm rushing through but I'm a little short on time and I want to make sure that we have plenty of time for questions ok so what I'm going to cover today is developing channels in four steps that's honestly all it takes then I'm going to cover a little what's new for developers in Panther and then a few advanced topics so what are the four steps for developing channels you create your channel you customize your channel you probably have to debug your channel and then you deploy your channel I'm going to talk about creating your channel first so the steps to creating the channel all involve using Xcode our development environment which you've probably all received on your CDs and the first step that you want to take is launched Xcode and create a new project and you'll find that in your list of choices you can choose to create a sherlock channel we've provided a template for that kind of project choose to make one of those next you're going to be presented with a panel to save your channel project somewhere and make sure you save it in an HTTP accessible directory when you deploy your channel it goes out on the web but to be able to test your channel locally it needs to be in either of a global web server documents folder or maybe in your sights folder in your user directory next make sure you turn on personal web sharing it will save you a lot of pain you're going to wonder why your channels not showing up and it's because you forgot to turn on personal web sharing so you do that in the sharing preference panel in System Preferences finally go back to Xcode and build and run your project basically Sherlock's gonna launch and it's going to launch with the right environment variable set to get the development you in the development you you want to add your channel the Sherlock we've realized that this is an extra step that you probably don't want to do so in future revisions hopefully we will automate that for you but remember to add your channel this will prevent you prevent you this will present you with a dialog where you have to type in a little sherlock URL but there's one there by default so you really only have to edit a couple of pieces of it to make sure that it's pointing to your chip channels definition file once you hit add then Sherlock's going to display your channel but it's our channel because it's the one in the template so this probably isn't exactly what you want that's why you're going to customize them so customizing your channel involves two steps you give your channel its own identity and then you enhance our starter code to meet your specific needs giving your channel its own identity involved naming it describing it setting its identifier and then giving it a beautiful icon to really attract your customers to it naming it's pretty simple it's done in the localized resources plist file that's where all strings that could be displayed in multiple languages are defined in a sherlock channel so that you can see what that file actually contains I've highlighted the channel name key and then I've named my channel WWDC 2003 example in that same file you can describe your channel that's the channel description key and I've said this example demonstrates basic channel development tasks what's that going to get you well setting the name and studying the description is going to show up in the other channels view in our channel management view so you want to make sure that you describe accurately what your channel does sell it a little bit it'll get users to click on it set aside enta fire this is important not for your customers but for Sherlock if you've developed applications on our platform outside of Sherlock a Coco app a carbon app but you're probably familiar with the concept of a bundle identifier and this is basically the same thing but for Sherlock here I've set the identifier to calm a palatable you wdc 2003 example so just like with bundle identifier a three part string comprised of calm your company your product name will make it sufficiently unique that you probably won't collide with other channels finally the last it is to give it a beautiful icon this is really important it puts a level of polish on your channel that users are really going to appreciate I can't emphasize enough that giving your channel an identity that makes users want to double click on it in the other channels view is going to give you a larger customer base how can you give it a beautiful icon well briefly you can download the Aqua icon kit from our developer website or you can hire a professional design agency if you're not a graphic artist okay so you've given your channel and identity but it still does what our default channel does so enhance the starter code to meet your deeds back to the diagram that Wayne was using earlier channels consist of interface triggers and services at least from a developer's point of view that the stuff that you need to worry about customizing first we're going to talk about customizing the interfaces Wayne mentioned the interface is designed with interface builder it's the same as a regular native used in any other kind of app on our platform what's the point of the interface well you display a pretty picture to your users but also you need to set up data in the interface to connect your triggers so that when your user interacts with your channel something happens to execute a search out onto the web so here I've opened up channel nib which is the default nib that comes as a result of creating the Sherlock channel in the project template in Xcode and I've clicked on the search button and now I've gotten info about it with the project inspector or the nib inspector rather so with we mentioned earlier again you can assign these Sherlock names or Sherlock IDs to UI elements and this is where you do it choose the Sherlock item from the pop-up there and then your main view has its own identifiers and then you can identify the button so here I've named it internet search button okay this is going to be useful to us in my next example so let's move on triggers are executed when a value for a data store path changes or when the data store path is notified so you can programmatically just sort of touch a data store path inside of a trigger and that can cause the trigger to execute another figure to execute triggers tend to use javascript why because Java JavaScript is going to execute in a linear and more deterministic fashion than xquery if you're familiar with channel development at all or you've looked at any of our sample stuff in xquery you can return a dictionary right and the keys can be data store pads and you can be setting values to those paths but there's no guarantee that if the dictionary has say four items in it they're going to return in that order so sometimes order is important so it's better to use JavaScript and data stored outset so here's an example of a trigger and I'm going to whizz past this screen because you probably can't read it but triggers tend to live in a file called channel XML and they look something like this so think back to that inspector where we set internet search button action is one of the default datastore paths for NS button you're going to want to check out our documentation on the web the inside Mac like documentation all of the default data store paths for any particular kind of object are listed there including an expectant actions so briefly what this triggers doing is using data store set to set the results table to a particular setting it's an all set and see it out it's turning on the network arrows by another default path thought animating and then it's kicking off a search by notifying or catching another data store path to perform the search ok services you want to perform your search you want to do this in a service so that next data store pass will probably execute a search service services are called by triggers they encapsulate data source transactions is Wayne with mentioning um we find that this makes it easier to maintain a channel because it's much more likely that your service is going to need periodic maintenance when the web changes so to isolate that from your channel trigger code means that when you need to change to accommodate a change to a website you're only changing your services file you don't need to upload your whole channel file again they tend to use xquery because it's a great XML parsing mechanism so again you can't really see this but soaked XML is actually a services file that we shift today and we use it ourselves in our shipping channels and basically this is just a definition of a function called soap query it takes a few parameters it's using the dictionary call to set up HTTP headers and then it's doing a post with the headers and asking for the data back from that post returning it pretty simple to execute a soap query okay so I've gone running through how you can make your channel you get an identity customized it to talk to your web service and return your results to your users and ideally it would just work fine but they probably don't be and if the web changes as it often does and your service changes you might need to debug it debugging and channels is a little different than debugging a cocoa a poor a carbon and so you need to learn a few new tricks first you need to make liberal use of message and debug statements which are sort of like printf but messages for xquery and debug is for JavaScript more importantly i think is liberal use of the xquery and javascript channels during your channel development phase I'll explain why in a bit finally there's the enhanced a bug menu which Wayne mentioned we've had a de bug menu all along but we've added a lot more interesting stuff to it and Panther a lot more useful stuff for you first message in debug again message is used in xquery code basically this little sample is getting the HTML down from Apple's website then it's logging it out if you execute message statements you will find that they if you're running Sherlock from within project builder or rather Xcode as we are in this example you'll find these message statements in its console but if you're just running Sherlock stand alone without Xcode you're going to want to look in console app for these messages so it's logging out the HTML from the site and then continuing along and returning what it wanted to return from the service similarly you can use the bug I've basically done the same thing here just making use of the xml query JavaScript object and calling document getting the data debugging it out to the console and returning it more importantly though as I said xquery and JavaScript channels you didn't see the JavaScript channel earlier but it's the same concept as an expert channel which we did demonstrate why do you want to use these you really want to unit test blocks of code as you're developing your channel so that when you paste it into your channel file you just know it works a caveat though in your channel file because it's an XML file you need to escape special characters so you know a less than symbol would have to the ampersand LT colon to work in your channel file to work in the xquery channel you don't want to escape it it's not an XML file so you just need to sort of global search and replace ampersand LP for a real less than sign make sure you do that so a little picture of what these do here have got an xquery channel a picture up there I'm getting again the data from apple com I've got a little xquery execute to grab all the image tags and then I'm asking for their storage attributes and when you hit run all the service attributes get put out in the results area similarly the JavaScript channel I couldn't really think of a good example so I'm just checking that five plus 16 still equals 21 and in fact it did finally the debug menu so the way you turn it on although someone's edited my slide to capitalized each and you don't want to do that if you want to turn it on with a default command which is executed in terminal defaults write calm down a pleasure lock Sherlock debug one the next time you want your luck it's going to come up with the debug menu and there are a number of things we've added you can turn on and off different levels of logging you can turn off HTTP caching which is pretty excellent as you're developing a channel because you're making changes all the time so you'd rather just have the fresh copy right away as soon as you've made a change you can look at the data store and also tickle the data store you can change its values or notify things you can look at your NS view hierarchy all kinds of good stuff in there all right so hopefully now you've got the tools to debug your channels and you're ready to deploy it so there are a few things to think about when you're deploying first is so you want to use subscriptions and checkpoints once you've decided all that you got to figure out how to ftp your files to the web server of your choice and then you just submit your channel apple and it shows up in our other channels view this is kind of a wordy slide if i'm going to gloss over it subscriptions and checkpoints so the subscription file lists channels you're deploying it's useful when you shoot multiple channels like Apple does so we use subscriptions for for instance our apple channels are other channels which are the third party channels our channel development tools all of those things that show up in the left-hand column of the channel management view they will increase your channels visibility if you choose to use a subscription for that very reason that they'll show up as a separate folder or collection on that left-hand side of the channel management view and they're also very convenient for your user because if you're shipping multiple channels if you want to deploy them one by one we user have to click on a URL each time to add a channel one at a time so just ship them all at once in a subscription and they just have to add the subscription they're done why else are they useful well subscriptions allow you to control who sees your channels in a subscription file you can require specific sherlock versions or require a specific geographic region for instance okay now that you've decided to use a subscription file perhaps you need to wonder as to whether you want to use checkpoints water checkpoints basically you can designate certain files in your channel hierarchy as a checkpoint and it helps your lock to know what's change so if you change the mod date on your web server once you've deployed of a file that is a checkpoint Sherlock's going to know that it should take a look at everything below that and possibly update it all right so you're using a subscription or you're not you're using check going through you're not either way you're up to being your files to a public web server you could deploy on your company's web servers you could deploy on da map if you've got it on mac account you could apply on any HTTP server if you're using a channel for internal purposes at your company you can deploy on something like that but if the channel is external make sure you submit your channel to Apple we can't stress enough how much this is going to raise your channels visibility so when that's a bug menu usage the submit channel menu item and your channel will appear in the other channels collection alright so hopefully I should note at this point actually that the reason I'm glossing over the details of some of these things like how do you create a subscription file and what does a checkpoint look like it's because it is actually pretty well covered in our in our documentation and so if you take a look at the inside Mac likes documentation on developer apple com also you want to take a look definitely at the release notes on your cds that you got in developer documentation release notes because we took great care to update them with all the new information which is what i'm going to talk about right now so what's new for sherlock channel developers in Panther we've got some user interface enhancements we've got interop location communication abilities that weren't there before we've added some support for address book we've added per channel health support for help viewer and we've added some versioning capabilities so that you can adopt all of these things safely first off the interface enhancements in an astable view we've changed it so that you can turn on type selection in columns or an entire table you have more control over whether users can delete rows or not you can set the scroll position of the table you can have checkboxes in table cells and table sorting can be done for you automatically we change the NS combo box to their we've changed it so that you can turn on text selection text selection on first mouse down or you can turn that off and you have just generally greater control over the list behavior the HTML view of course is now using the fabulous WebKit and that's going to add a lot of capabilities if you want to display more complicated HTML you can set the default car set so let's say you've narrowed down a chunk of HTML in one of your services and in so doing you've managed to strip out the car set tag you can just tell the web view that every time you're displaying HTML that's what car set should be whatever finally you can turn it on you can turn on browsing within Sherlock so links will be followed with in your HTML view versus if the user clicks on a link now in Jaguar rather if they click on a link it will definitely be sent out to the default handler for HTTP URLs so you can actually just browse with interlock now because the WebKit is powerful enough to handle that inter application communication so Sherlock is a playground and that makes it safe for users and we think it's pretty easy to develop for but not the only ass out there so maybe your channel wants to talk with other applications we've enabled this by using special URLs so there are address book URLs ical and web cal URLs to talk to ical and health URL so that you can open help you or from within your channel the way you would use these URLs as you create one in your in your channel source and then you send it to system the JavaScript system object with the openurl command and if the URLs in there the system object will decide what the proper handler for that team is via launch services and the right application will be opened address book support so as you saw in the phone book channel we've got combo boxes that do all kinds of neat completion they complete city-states they complete on titles in the users address books they'll even complete you didn't see this but they will complete on addresses in the users address book so that's done in the Sherlock address combo box we've packaged it up so that you can just drag it in interface builder drag a combo box in change the custom types to Sherlock address combo locks and you've got the same functionality we have in the phone book channel also there's a JavaScript address book object and through that object you can add things to the users address book and you can search the user's address book per channel health it's really good user experience it's its basic aqua savvy to provide help for your software and to do so in help viewer so we've enabled that in Panther basically you tell us where your help file is and we take care of the rest we add an item to the help menu that points to your channels help we open it when the user chooses that item you're going to want to take advantage of versioning if you take advantage of any of these new functionality of any of this new functionality though and if you're familiar with the concept of Gestalt sir anything like that basically you can check to see that something is there before you use it or you can check to see that Sherlock itself is a particular version before you use something and that's done by checking for the existence of new JavaScript objects you can call channel version from X queries and that will give you back the version of Sherlock and you can use version or max version attributes on triggers or services or subscriptions and again this is all covered in the documentation so i won't go into the exact detail very briefly because I know I'm running out of time advanced topics three of them the most important in my opinion localized resources printing and performance tips if you take advantage of any of these three advancing you're going to provide your user with a much better user experience localized resources so not everybody in the world speaks the language that you're developing your channel in and if you have the ability to localize your channel into other ANC's languages Sherlock will let you do that basically you set a localized base URL which tales tell Sherlock where to look for your localized resources and then you can access localized resources from your code as well so if you're setting a string dynamically so let's say you're setting a label from within a trigger with a data stored up set to the to the labels pack you would call localized resource get the right strings and then set it you can also call localized URL to get a URL that points into the right L proj directory printing channels can be kind of complex there's a lot of information in there particularly because you're aggregating information from multiple websites or you're trying to do better than a web page could do and so you're showing a lot of stuff i mean let's look at the phone book channel we've got tables of results we've got driving directions we've got a big map sometimes that looks great in Sherlock but it doesn't look great when you print it out on an eight and a half by eleven piece of paper and so I can't help but stress that if you print it out and it doesn't look too good your users really not going to appreciate that create a custom print view you just add any of you to your nib you reorganize your UI elements so that it'll look good for eight and a half by eleven and then if you do that be sure to set your channels means you identify your data for path so that a Sherlock loads your channel it knows that one view is actually the view to show in Sherlock and the other view is your print view performance tips nobody likes to use a channel that's slow and we've been working to make ours faster and I want to share with you a little bit of what we've learned about that a void initialize globe initializes with special chunk of code that all execute before your channel shows up there's a lot of stuff that we were doing and initialized that did not have to be done before the channel appeared if you are doing stuff that doesn't have to be done and initialized move it to a later trigger execute any given X hath only once so let's take a little example let's say I download some HTML with the document command and it's in a variable dollar HTML and I want to get all the anchors in that HTML and then I'm going to need all of the anchors hrs and all of the text for those anchors well I could say dollar HTML / /a flash text and then dollar HTML / /a flash at href but since I'm doing / /a twice and that might be expensive why don't I saved that in a variable next favor cash update for infrequently changed resources we've made use of this ourselves and basically it's a flag that you can set on an HTTP request and if you know a resource out on the web is I'm going to change very often there's an image out there that's pretty static if you set that flag you're able to get the image from the cash first and then Sherlock will go check to see if it's changed and pull it down in the background so the next time you access it you'll have the new thing in the cash stream return data into the view as it becomes available examples where we do this with a pictures channel in the internet channel if you have some info first and you're waiting for others don't make your user wait splat it out into the view and wait for your stuff and then splat the next stuff out finally show cache data first and then refresh we mentioned this as a tactic for having a good channel user interface we do this in the movies channel if you do a movie search and we get your list of theaters and and movies will show that to the user again the next time they launch and then updated in the background so I'm going to invite Wayne back up for a wrap up for our session thank you Jeff so in summary Sherlock allows you to deliver web services today you can create them quickly there updatable on the web they provide a native aqua you I much like an application but you can link to them directly from the web or launch them from the dock and in Panther they're built right into Sherlock so for a road map now of course all of these sessions have already happened but for those of you watching on DVD or if you'd like to get the dvds the internet technology safari over to provides a high-level overview of the technologies used by Safari and of course by Sherlock as well the WebKit and the foundation URL API if you'd like to add help tier channel then you might be interested in session 408 for the apple health updates and how to's and the next one there is more about Safari and web standards which again is interesting for HTML views and such and then the session internet application development the new frontier is an environment provided by macromedia that aims to provide Internet applications that may also be of interest if you're doing a lot of graphics like you would in a flash kind of context so and of course our friend jon is is the guy to contact if you'd like to ask for features or any sort of thing like that and for more information there's the Sherlock developer web page which is very easy to get to developer to the apple.com / Mac os10 flash Sherlock has all the information you need there there's a mailing list if you'd like to ask questions if you're in the midst of channel development and you went into a problem you're not sure how to deal with please ask on the mailing lists we're more than happy to answer questions there or other developers will also chimed in an answer inside Mac os10 Sherlock channels is the documentation for how to create Sherlock channels and that's up at the developer website and it's also on or disc and then of course the release notes will tell you specifically new features that have been added in various releases along the way including Panther if you'd like to learn more about the JavaScript language there are lots and lots of references out there the sort of main standard reference is out on the ECMA site and there's the URL there but of course there are many books out on JavaScript xquery is much newer of course and it's not yet a final standard and so there really aren't as many references out there but the the main reference is at the w3c site and this is both the language and then the function to provide you