---
title: WWDC2004 Session 405
framework: wwdc
role: article
path: wwdc/wwdc2004-405
---

# WWDC2004 Session 405

## Transcript

Kind: captions Language: en thank you thank you and good morning got it I went backwards already there we go this session is called understanding document binding and I thought that I should start by explaining what we mean by document binding so we know what we're talking about one of the breakthrough or revolutionary features of the original mac back in nineteen eighty-four was the ability to let users double-click on a document and have it open in the right application or an application that could work with the document and this was revolutionary just because the user didn't have to figure out which tools to use anymore the user could just start working on a document and it's still a very critical feature today so very narrowly defined document binding is what makes that work it's how the OS associates documents with applications that can view and edit them and on Mac OS 10 that service is provided by the launch services framework so that's the technology we're going to be talking about for the next hour I'm specifically going into what's new with launch services on tiger first I gave a very narrow definition launch services actually does more than simply associate documents and applications and I wanted to review what those things are it's an API that is used heavily by the finder and the doc other applications third-party applications to open things there's API that can actually just open an application open documents and on Mac OS 10 we added the ability to associate URLs and specifically URL schemes with applications that can handle those URLs and so there's API for opening all of those things and creating new applications in the users workspace as I said it in order to make that work launch services figures out and keeps track of application document bindings so it looks like your application looks at your info.plist and figures out what kind of documents and urls you can handle and it remembers all those associate now with so many applications available today there's often a number of applications on the system that can handle any particular type of document and launch services keeps track of user preferences so that we know actually which application is preferred when the user clicked double clicks on a given document and then finally because there are certain things provided or related to document bindings that appear in the UI such as in the finder in another application such as kind strings for a document localized display names for documents and applications and folders there's this abstraction layer a thin abstraction layer above the file system that launch services provides additional attributes that appear in the UI that give us the nice user experience that we expect on the Mac so those are the things that launch services does and I'd like to talk then about the topics and get this to work the topics we want to talk about today as far as what's new in launch services on tiger now first one is actually not new uniform type identifiers were introduced in 10.3 but they were very specifically introduced for one purpose which was to support the new carbon pasteboard api and they're going to be used much more widely on tiger and i want to give a quick overview of what they are how they work because it's relevant to the rest of the session uniform talk identifiers are going to be used in a new way to declare your document kinds in your info.plist so that you can simplify your info.plist and benefit from other features that UTIs provide and then there's three new sets of API and launch services first one is a new way to access item attributes that's the abstraction layer over the file system new API for actually setting and reading user user binding preferences and new options for opening things new ways to open documents URLs and applications I've got a little spiel about security and how it relates to launch services and I want to finish up with some interesting ways in which we're extending the whole idea of opening things and how what kinds of things can be opened in the users workspace let's start with uniform type identifiers when Mac os10 was introduced we wanted to play really well with the rest of the computing world one of the controversial things we did was recognized filename extensions we also wanted to work really well with the Internet these things were all facts of life that we had to interoperate well with the computing world and it led to a kind of Tower of Babel as how as far as how we identify data and file system object types on the system and to use an example of this these are all the different ways that TIFF data might be identified on 10 on Mac OS 10 there's a mind type is to filename extensions that are distinct but they mean the same thing there's Coco's and asked if keyboard type for the NS pasteboard and then there's the tip OS type which might be on the carbon scrap or it could be associated with a file on disk and there was no system service to kind of tie all these together and make it clear that they were related there was internet config but it didn't didn't cover all of these namespaces and it was really geared towards the internet and we wanted to provide a general service for abstractly recognizing types and that's what UTIs are we decided we needed to introduce a new name space because none of the existing ones really did the trick they were too prone to collisions or in order to avoid collisions like mime types they required registration and there were all sorts of mime types that aren't even declared or don't exist yet that we wanted to associate with the files on the system and so we didn't want to be tied to mind types and so we create a new naming convention called uniform type identifier this is an example of public TIFF and what's key to making it not just another name space is that built into the system use the ability to map it to other type namespaces and so the API associated with UTIs allows you to go back and forth between a UTI and a mime type filename extension and so on so it's very easy to give it a file figure out what its UTI is given some data on the pasteboard see its UTI and so on so that's one thing that's built in that helps us make sense of all this type identification stuff you have to bend down like this to get the slides to go forward what about the namespace well we Monaco's time was introduced we borrowed from Java to use the reverse dns name space for bundle identifier and in a way bundle identifier is the modern replacement for the Creator signature on an application so it's kind of natural to extend that to type identifiers and so let me bring up a couple of other examples for types that are proprietary are owned by a particular organization we use the reverse DNS naming convention so comical depict is a quick draw picture data and calm dotted OB photoshop PSD would be an example of a Photoshop document now the important thing is that they're unique the name doesn't imply any sort of type hierarchy as with mine types but the important thing is that we using reverse DNS makes it naturally unique and we're not going to have to legends they're also kind of verbose you can read them you know what organization their associated with who to go to for more information about a type you're not familiar with and then four types that I really are in the public domain or not owned by any the standard types we just put those in the public things are the public domain public dot so that it's clear that they're UTIs and that there standard now I mention the type hierarchy with mime types we wanted to go further than that the mime type hierarchy is very fixed it's built into the name and fairly simple you've got images audio video text and we felt it was important to have a runtime actually identified types in a hierarchy and as we go through the session and other sessions later this week you'll see how that hierarchy is useful these are all examples of images the same types i had on the last slide and so they are declared as being subtypes or conforming to public image and abstract type and this is important because users think of these files because images and by associating them as subtypes of something called public image we can associate certain attributes that are associated with images such as the resolution height width and so on this is something that spotlight uses a lot for building the metadata store to go a step further all images are data streams and so pretty much every file on disk is a subtype of public data because it's a data stream but because it's a multiple multiple inheritance hierarchy we can add other tags if you will or names to a type and content is something that reflects document content something that when user double clicks on it it's going to open as a document something they can edit just some other examples of abstract types like that let's look at sub types of content we've got images of which I gave few concrete examples we've also got public text which is anything which is texting coded now this is by the way this is not going to be a complete overview of the type hierarchy this session is not really supposed to be about UTIs but it's important to get a feel for what it's like and there's some documentation I can point you out later another one is audio-visual content which is a way to of all time based media audio and video together we can also model different kinds of directories so we use directories in a lot of different way a lot of different ways in the file system now but the root type for directories is public directory and everything pretty much goes into two categories either it's a folder which is something the user can navigate into or it's a package which is something we define as something that to the user looks like a file an example of a concrete package is an application bundle and then finally I wanted to give another example of how multiple inheritance can be used there's several kinds of applications on the system there's application bumbles there's also files with type A ppl which can be applications and so we have an abstract supertype condotta filled out application and you can use that for instance in a file selection dialog if you filter for just one UTI com app about application the user will be able to select any kind of application whether it's a bundle or a file so it gives us this very rich type description model and it's extensible because the namespace of naturally avoid collisions you can add your type to the hierarchy and you do that by putting it a dell oration your info.plist it's some xml pretty simple it's similar to how document types are currently declared you give the type identifier you say what it conforms to and then you list out the different kinds of tags or other name spaces such as this one has to filename extensions and one mime type and that's how you create automatic mappings between the UTI the abstract type that is and specific namespace tags so those are the key points about UTIs we've got naming conventions that ensure uniqueness it gives us an abstract idea of what a type is independent of all the different namespaces they also exist in a hierarchy which gives us a nice model for filtering and associated metadata and the key is to declare your own types so that other applications can take advantage of them and you'll see some advantages of that later on in 10.3 there were not a whole lot of types declared because as I said it was targeted really in just a baseboard but we've added a lot more there are string constants for them along with some commentary in this header UT core.typed H so enough of that let's go on more specifically to launch services and how UTIs can simplify your application development when you declare your document types that is what kinds of documents you can open in your application it's fairly laborious you have to even four basic types like JPEG TIFF or txt files you have to go through and you list every possible OS type every mine type every file name extension that you want to recognize it's kind of very literal and there's no notion of abstractly recognizing the type and that means every application that opens JPEGs has to come up with the right list of JPEG identifiers and more importantly if you open text well there's no way in the world you can possibly list every file name extension that might be a text type so UTIs allow us to simplify that process and leverage the type hierarchy and type knowledge contributed by other applications on the system they also let us do nifty things like inherit icons and kind strings so to give kind of an extreme example here is this is pulled from a preview app this is not even the whole type declaration but this is just for three types we've got a tip JPEGs and ticked and it's saying that it's a viewer for these three types that lists all of the different filename extensions and os types and it provides an icon and a kind string and it's a lot of text i purposely made it unreadable that's the point it's small because there's a lot of it and I had to fit it all on one slide on tiger you can simplify all that we've got one dictionary here of listing several document types and he uses a new key LS item content types and in its array it's an array of UTIs claiming JPEG TIFF and picked the same three types from the last slide and it says that the application is a viewer for these types and it doesn't even if you don't want to you don't even have to provide an icon or a time string because the system will provide the default icon and time string associated with those types you still can if you want to have a branded icon when a file is bound to your app you can provide an icon but you don't have to you don't risk having a completely generic document show up document icon show up by not providing one so as you can see this is much simpler it and it allows all applications using this style of declaration to have the same definition of what a JPEG is what a tip is and what a pict is so everyone's using the same extensions same OS types because that's controlled elsewhere by the type declaration another way to think of it is that we took what was document type declaration that we split it up into an abstract type and then an association of the type with a role in this case viewer another example I call this a free lunch because if you want to claim to open all plain text files the advantage of doing this is that you suddenly gained the ability to open a plain text file declared by some other application on the system so you don't even have to know what the extension is or how is identified as text you rely on the system to determine that and you if you declare this this way then somebody will take a plain text file try to drop it on your application and they'll get the right feedback and Kim then the document can be dropped even though you might have no idea what the extension is back to directories up until now we've had kind of no modern equivalent of the old fold and disk OS types that were used to allow folders and hard disks to be dropped onto an application now we have UTIs for those as well as for package types and so on and those can be listed as LS item content types in your p list so i think what i should do now is switch over to the demo machine and just give an example here of what I've been talking about in the example I picked picked is text of it because everyone knows what it is and sample code or the source code is available as an example on the DVD you received so we're starting out with stock text edit and let's see what it can do now I'm going to show a series of drag and drop operations because that's an easy way to test document binding you get feedback as to whether the application is going to accept a document and here's a plain text shopping list so obviously that is going to work there we go and let's move along here's a dot C file source code is it going to be able to handle that probably here's some HTML i'm not sure what it's going to do with that but it is tech so let's see okay so actually text edit knows how to render HTML that's kind of nice gives me a nice rich text display now here's a PDF that's not really a text file but let's see what text said it's going to do looks like maybe it is going to open it and that's kind of disappointing isn't it it's kind of a downer because it looked like it was going to do the right thing and and it really did this this just that's not what I want well so that's not so good I wonder well I wonder what would happen if I grabbed a hard disk drag what it looks like you can open those two at least it didn't try to display the contents of my hard disk so it gave me an error message instead well what's going on here textedit want to try to open anything and there might be some good reasons for doing that because it can be it gives a stab at recognizing anything is a text file and trying to display it but in the only mechanism by which currently of it is available to be able to try to open anything is to essentially claim to open everything there's a wild card in TextEdit CP list and let's go take a look at the Xcode project here if we go to the expert view of the plist editor barely readable I can't make it any bigger here's the CF bundled document types and if we look I think it's number three yeah this is of the plain text claim and we look at the extensions it has txt txt and asterisk and that asterisk asterisk is really what they don't even have to list anything else in there p list if you just list an asterisk it says let anything be dropped on this application and with UTIs we can do a little bit better than that and I'm going to go in here and just get rid of everything and I even want to get rid of most of these here go to the icon linetypes typename OS types that we've got the role it's an editor and i'm going to create a new key LF item content types and if I don't get it exactly right it'll be a sad demo and this is an array and let's add a UTI here public text this is saying open any kind of text file by the way the difference between text and plain dash texture that is that text includes things like HTML or RTF textbook markup plain text has mil mark up so I built it I think and let's see this is the this was actually the build target right here let's see what happens we can still open shopping lists you can open dot C files even though textedit knows nothing about the dot C extension or claims to know nothing HTML well the system recognizes that as a subtype of text so we can still drop that if we grab PDF however it won't let us drop it anymore cuz PDF is not a type of text and why don't we grab the hard disk and sure enough it won't let us drop that either in fact the finder is showing the that make alias icon because it's going to make an alias in this folder if I drop it here so we've improved the user feedback there and simplified the plist at the same time now just one more quick example suppose for some reason we wanted to add back the ability to open volumes textedit suddenly could browse volumes so let's add one more UT IM here there we go and build that and we should be able to drop that if we wanted to so by adding one value to the plist we can really get very precise definition or declaration if you will of what kinds of documents your application can open and these will these associations will work back to the slides I guess even if even for double-clicking if when you double-click a particular kind of document if there's an application that specifically claims that UTI or document kind it will be preferred but if there is no specific applications available like that then an application say claiming plain text will become a candidate for opening a text file so one problem with all this is that you're going to start getting open document events Oh doc Apple events for files that you may not know anything about you may not recognize any of the metadata associated with that file so you need to know what kind of file it is and for that we were providing new API and launch services there's a new content type property associated with everything on disk it's not actually on disk but you get at it through launch services there's really no need to store yet another type identifier on disk because we've got filename extensions we've got our less types and so the content type is a UTI that is essentially derived from all the available metadata and you just have to have to ask launch services what the content type is and then you know and it may be a very specific subtypes again you don't know anything about that you can test it for conformance to the types you do recognize so if you recognize playing text you say ok I've got its UTI does it conform to plain text us you ask us that and we say yes and then you know what to do with it now as far as API to get at the content type attribute we could have just added a new method and say given this FS ref what is the content type and the reason we didn't do that was that we kind of have been adding a number of those on with each release of Mac OS 10 first there was the kind string that you could get for a file then there was the display name and the problem is that each of those introduced io or cause I owe to happen so if you have to get several attributes the i/o gets done over and over again so we've generalized that to two new functions LS copy item attribute and more interestingly LF copy item attributes a bulk call so that attributes have names and you also have to provide a role mask which means you know you're asking for an attribute as an editor or a viewer because the role can affect the document binding and you get back a value which is often a string that it could be any core foundation object types such as a boolean a number in the case of the bulk call you pass in an array of attribute names and you get back a dictionary of key value pairs and the bulk call is really nice if you know what attributes you need in your ear you I what you're going to have to display or work with you can ask for all those at once and we only have to do the i/o once on the file to get the attributes so there's a number of string constants naming the attributes now in the launch services headers the attributes include and there's a few other ones but the major ones are the content type which is the UTI and by the way content type is also the term used for spotlight for the metadata framework which you'll learn a bit more about tomorrow and it's very important property for categorizing metadata and then the content type is the only new attribute we also provide the display name the kind string and just for completeness in to allow bulk access you can get the type of the creator and the extension of the target object so that's the attributes API I want to go on now to the next set of API which is new and tiger which is setting handler preferences I didn't want to go through I probably shouldn't say this I didn't want to go through another WWDC without being able to say that we can essentially replace the internet config functionality finally I'm Mac os10 and that's what the Preferences API provides is a way to do part of what internet config disz would internet config did which was associate file types and extensions with a creator code that would be the default handler and also associated schemes with a creator code which would be the default handler for a given URL and we've tried to keep it simple in that spirit but using the type the data types that are in common use on Mac OS 10 so the terminology goes like this a handler is an application which is capable of opening a particular kind of document or our particular URL scheme and for a given a document type or scheme you can get what the default handler is that is that the one that the user prefers you can get all the known handlers in a list and that's useful for driving in you I say for a pop-up menu and you can set the default handler now handlers are specified not by a specific application instance but by bundle ID and so it allows us to pick the user's preferred say if if if if an app is already running for instance and the user prefers that bundle ID we're going to use the app that's already running not another one on disk so when you set preferences you give a bundle identifier and as I mentioned just pretty much replaces a key part of the Internet config API so here's a simple example contenttype handlers are driven by UTIs expressed as the content type in this case a JPEG if you were to ask launch services for a list of possible handlers you would actually get back a pretty long list of JPEG handlers on the system but to simplify here 3 preview of course which is the one that ships out of the box is the default bbedit can actually display JPEGs I found and Internet Explorer and each content or each handler has a role so this is saying that the default viewer for jpg is condotta Apple dot preview and so if you ask the default viewer you'll get back that bundle identifier if you set the default viewer to BB edit it will create an association to handle JPEGs by default in BB at it now here the API is real quick all I need to say about them is that there's three functions for utis you can get the default role handler copy all the role handlers to get a list of bundle identifier and you can set the default role handler these are in the headers so you don't need to like type fees or anything it's a little bit simpler for URL schemes but the same idea you just you can pass any URL scheme there's no roles with you are handling URLs but you pass any URL scheme you can get the default handler you can get a list of all the available handlers for a given scheme so you passing HTTP you give up all the browsers on the system for example and you can set what the default handler is so very simple API and this is something that developers have requested for some time there are various reasons why in your preferences dialog or add application launch you might want to give the user some choice about us making your app the default but I want to put some guidelines out there for setting handlers that you need to remember these are because we're taking a little bit of a risk by making all these pub because they can be abused the idea of these AP is is that they set user preferences not developer preferences you may want all of your documents and URLs to go to your application but this is not an invitation to just slam the settings all of these should be used with the users dishes in mind so you're going to be changing preferences you should be informative about what you're doing what you're changing give the user a choice and make sure that you have the users consent you follow what the user asks for and don't pester the user I know that there's a desire sometimes on first launch of an application to ask you you know if you want the app to be the default handler and you know that's okay throwing up an alert ism isn't the ideal you I but just don't do it every time if the user says no the user has said no the user says yes great the third set of new API for that I want to talk about today is opening things we've had a bunch of developer requests over the last couple of years and they've piled up enough so that we can provide to them all in one fell swoop so I actually tried to include everything we had a record of in our bug database for the things people wanted from the ls open calls those include getting back that getting back to process serial number when you open a document or an application shut up he works with me the initial apple event so you can you can put together any arbitrary apple event you want and pass it to an application that you're launching passing in arguments which eventually get sent to your main which is useful if you're launching some unix or unix oriented utility and is also setting up an environment any arbitrary environment that you want for the launched application and then finally being able to open a document with a specific role so if you want to open a document for viewing or specifically for editing or for some other role this API lets you do that so what does it look like well first of all there's a structure which is used by the three functions which are going to follow and inside the structure is everything related to specifically launching in applications that is nothing related to documents or URLs but just specifying an application and how it should be launched its called LF application parameters and there's launch flags which are already used in the old LS open API there is an FS ref for which application should be launched and then there's some other things like the environment has a dictionary of key value pairs are the command line arguments as an array of strings and the initial apple event and this is nice you don't even have to flatten the apple event like you did with the process manager api's you just create an apple event and pass it into this in this structure and it will get delivered as a first Apple event to the target ad and so if you want to open an application you have this simple function to call LS open application you passing the parameters structure that we just looked at and you get back a process serial number that's a nice simple one but you can also open an array of items or documents I don't call them documents because they might be folders or packages they could even be an array of applications I suppose but it takes an array of FS Restless of FS reps and a role to open it in you can pass in all roles if you don't really care you can set the application parameters if you want is that is if you want to open the document in a specific application you can specify that or you can leave the apt params no and let launch services pick the application and you get back actually an array of process serial numbers this is usually you passing one item and you get back one process stereo memory but if you ft in 10 documents like sometimes the finder does they can each go off to a different application and so you get back an array of process serial numbers which is a parallel array telling you where each document was sent to and then there's a similar API for URLs in this case it's very similar except that you have an array of URLs to open these could be document URLs by the way which is especially convenient for say Koko apps you can pass in file URLs here and they'll be handled as documents okay that's all the new API want to talk about there's a few other odds and ends but that is the bulk of it it's new in Tiger now I want to talk about security just earlier this month there was a security update that went out and launch services was in that security update in fact it was it was happening just as I was trying to gear up for WWDC so it distracted me for a while but we actually want we had to change the launch services behavior in order to avoid running an application that the user didn't trust it is an application which the user may have downloaded perhaps accidentally and then maybe the user clicked on a URL on a web page and that application was a handler for the URL and it would get launched so there's a small chance there could be a malicious application that got launched this way we didn't actually have any cases of this but we wanted to close that up as soon as possible so the important thing I want to pass along is kind of what changed in launch services and and also how you guys participate in maintaining security with respect to launching things the main goal was don't run untrusted code without user consent in this context untrusted code we define as an application which is never before been launched if the application has been launched we take that as kind of an implicit statement trust the user asked for that application to be launched if it's a malicious app once it's launched kids done its thing running it again probably even going to be any worse and furthermore it's the user system we have to allow the user to do what the user wants to do so once an app is launched its trusted but if it's never been launched before then we don't necessarily want to trust its bindings that is we don't want to use it in particular when user double clicks a document or open the URL which is bound only to that application so the design principles we kind of to be really careful because we didn't want to ruin the user experience but the design principles are do what the user is asking for when we're evaluating document bindings and URL bindings always prefer trusted applications if there's several choices of applications pick a trusted one one that is the user has run before if there are no trusted apps then give the user a chance to intervene and stop an app from launching that they may not be expecting but then once an app does launch trust that application in the future so this results in a minimal I guess disruption of the user experience but now if the user double clicks essentially winner winner an app is first installed on the system or it's downloaded it's in an untrusted state and if the user launches that application there's no intervention know you I if the user drag something and drops it on that application that's an explicit gesture to launch an application but if the user just put the URL in the browser and we're about to launch an untrusted app then we actually will show some UI and it's a warning the internet location you are opening will open the application malware for the first time are you sure you want to open this application and this is the chance we're giving the user to intervene and say no and there's no default button they have to make a choice and so this this is the the way we came up with to minimally disrupt the user experience but also give the user a chance to stop an application from running unexpectedly so what are your responsibilities in making all this work well as I said if the user double-click same application we're going to launch it and all the Finder is doing is calling LS opened on the application so likewise if you are going to launch an application we're not going to put up a dialog asking the user if this is what they really want to do so it's up to you guys to make sure that you're launching an application which is trusted either it's an application you know about like it's one of one of the applications in your suite of applications when your helper apps or it's something that was explicitly selected by the user like in James Thompson's drag drag thing is a launcher app so the user clicks the tile there it's essentially user consent so those are the main things if you launch an application either it's one of your trusted apps or something the user explicitly asked for if you are going to open a document or a URL generally just let launch services choose which application if you pass in a document and a specific application to use it's like a dragon job Chester its interpreted as an explicit request to launch an app and we're not going to pester the user with an alert in that case but if you just say open a document and let launch services choose that is specify no for the application then you'll get two benefits first of all it'll be respecting the users binding preferences because LS will follow that choice and it will also enable us to show the consent alert if it's necessary to block an untrusted app from launch is one other new thing in Tiger which we want to build awareness of and over time will help us improve security we want to encourage people to use a new role of shell role shell in your info.plist be prior to tiger the only two roles you could list in your info.plist where editor and viewer and it turns out that there's really another kind of document commonly in use which isn't really a document it's an executable which isn't an application it could be a jar file a Java you know a java application or an apple script or any other kind of proprietary scripting language and double-clicking it is going to execute the program in that document and if you are offering that kind of service for one of your documents put it in your info.plist as rural shell this will allow us to know that you're not actually going to edit or view the document you're going to execute the document and so there may be special security measures that we want to provide in the future in order to help the user know what's going to happen for instance we might change the appearance of things which are going to get executed when they're double clicked I might look a little bit different than regular documents I'm not saying we're going to do that in fact we haven't even tried that but it's a possibility so likewise if you if if all executable files are claimed with rural shell then when you go to LS open something if you don't you want to make sure it's not executed you can just specify roll editor a roll viewer and will refuse to pick an app that claims roll shell for the type of document that you're opening so that's something new to tiger and we just are encouraging people to start using it it will become more useful over time now the last topic today I want to talk about is extending the open metaphor this is something I've been wanting to do for a while and it's fun to show it in Tiger now since the doc was introduced it's this really nice access point for applications and from the beginning we've been able to drag documents down to the dock and drop them onto application tiles and it's a great drop target because it's always there it's always at the top layer it's never hidden behind anything and I found that there were times when I was frustrated because there were other things I wanted to drag down to the dock and nothing would happen I would get hover over an application tile and there's no feedback you can't drop anything and so by extending the open metaphor I'm looking at what other kinds of things can we open currently we can open applications documents and URLs and we can do that through various methods such as the open menu command in the finder single clicking a URL double-clicking a document and then there's drag and drop and drag and drop is something that you can do with documents but you can also drag content out of an application window you can drag the URL out of an application window and when to be nice if we could do something with that in the dock and in order to really help you understand I'm just going to show it to you I've done this demo a couple of times now for various people at Apple and a common reaction is can't we do that already and that's very promising very I like that reaction because it means it's a natural thing and amazingly all the other stuff I'm about to do we can't do in panther in 10.3 so I'm in mail and my friend keith has sent me an email which I want to take a look at it says Chris did you see this morning's news about spaceship one this was last week and no I hadn't seen the name is about spaceship one but I'm wondering what he means and then I noticed Keith kind of a knucklehead and he put the URL up in the subject line and you know male doesn't expect a URL in subject line so it's not a live link like it would be in the body and invariably this happens right you get into some context where there's not a live link you've got a URL you have to copy it out onto the pasteboard go to a browser paste it in press return to get there and it would be much smoother if we could just grab that URL and drag it down say to Safari and have it open the URL so it's much faster and it got me here to this article about spaceship won the first privately-funded spaceship to leave the atmosphere and that's pretty cool and there's some control about the first successful test flight and some photos but I really actually would like to get to the spaceship one official website and I'm wondering if there's any way I can do that well maybe I can grab this and drag it down here that's not a URL so what is Safari do with it well it does a google search on it and the first the first hit here is the spaceship one home page so let's go there and see what we've got here it is they've got a bunch of information about the spaceship and the test flight and let us at other some photos whole photo gallery and I happen to know because I've rehearsed this that on this page there's a photo of the cockpit which was kind of interesting it's it's pretty simple for a spaceship don't you think but I kind of would like to get a closer look so I'm going to grab that photo and drag it down to preview and drop it on preview and I get a new window here in preview whoops subscribe to preview and that's kind of useful because I can zoom in I'm not really getting more resolution but I can see it a little bit better and I can grab it around so it was just a nice simple way to get an image into another application maybe I want to save it at this point or I can even drag it into an image editor now let's go back to the website and here's the press release page and here's their press release for their announcing the first successful flight and maybe I want to send that back to keep my friend Keith I'm going to do select all and grab that and drag it down to mail and I get a new message ready to be addressed to mail doesn't have the image yet but we're working on that and so you can see it's all very natural gestures saves time and it really leverages the dock as a great drop destination now if I can go back to the slides now I get to one of the coolest parts about this is that i didn't have to change those applications except for preview i made no changes to those applications to make that demo work i added about five lines to preview in order to allow it to accept the drop but otherwise mail and safari were already set up to do you wonder how can that be and the way it works is that we already have a very well-established mechanism for working with data on the pasteboard coming from another application and that is the services menu applications in there info.plist can declare services and they show up under the under the application menu who say for male you can select some text go to the services menu and you see a bunch of services offered by other applications that operate on text for example and this is really then just a new way to invoke a service so we're integrating existing technology with the doc and this is the details of how it works some of the details I guess we do use an apple event in order to send the data between applications because we want it to be all asynchronous and so there's a new apple event ka e open content or Oh calm and it is simply it's very similar to an ER doc event except instead of a list of document references it's a list of data items of AE desk and each desk contains the data to be open so when I drag that image out of Safari down to preview we created an open event we stuffed the entire image into the yoke I'm event and we very efficiently moved it between processes delivered it to preview but preview doesn't have a no con event handler and none of those applications have a note on event handler you can choose to handle the hook on event directly if you want or you can allow look you can allow launch services to handle it for you and what launch services does in Tiger is it installed a system default handler for the Oakland event and when an old kind of event goes unhandled we look at the current applications list of services and we look to see if they're a service that the app provides which can handle this type of data and if there is we just invoke the service so if you adopt services not only where you appear in the services menu but now you will also be able to you have the service invoked as a drop target on your application icon and we'll also integrate this into the finder for dropping things in the finder as well that is dropping things on application icons in the finder and that might be hit oh one more slide so you know some of this already went over you add a services declaration to your pee list and handle the Oakland event only if you want to and one other thing I want to say about how to respond to it usually the response in many applications will be open an untitled window you essentially get a new document untitled and it has all of the data in the okanagan but you can be a little more creative than that if you wish in Safari was a good example there it got some plain text it was able to take that and figure out that it should do a Google search on it because that's the most logical thing to happen in safari with a chunk of plain text so feel free to be creative so what are the main points i want to take want you to take away today they are the following uniform type identifiers are used much more widely and tired than they were on Panther both in launch services-karbonn pasteboard what else the trans- translation services carbon API we have plans and tiger to use them in navigation services for filtering and Coco has plans to adopt them more widely also in its API oh yeah Thank You Alan spotlight also is organizes its metadata around uniform type identifiers so it's a great foundational technology on the system we have new API for setting handler preferences use them don't abuse them we have new Ellis open functions with a bunch of features that you guys have asked for please try to follow our new guidelines for opening things and help us maintain security and the sister and finally using services now with integration with drag-and-drop gives you a great new kind of portal into your application increasing the value of your application to the user and I am done now I think we have one more is documentation we have some documentation now on uniform type identifiers we just finished a couple of weeks ago and it's available on the wdc reference library site and also it didn't make the DVD but I encourage you to read the release notes also the launch services release notes not everything you've seen is implemented yet and so it's good to read the release notes before you get frustrated we're going to get it to you as soon as we can