WWDC2003 Session 418

Transcript

Kind: captions Language: en hello hello welcome welcome session for 18 as you say internet technologies advanced foundation URL so this week here at the conference we've introduced the new URL loading API it's going to be in foundation I expect probably a lot of you heard something about it while you're going to be hearing a lot more about it in this session of course and yes see so there's sort of I guess you'd say good news and bad news the good news is I think you're really going to like this API sort of the bad news as well there are some new things that maybe you're going to need to learn about new classes new api's but there are really also some new features which I think you'll find interesting and useful to you disk caching cookies authentication a couple of more things and we'll be talking about these in the whole rest of the session until what why I do okay so URL loading are we talking a lot about URL loading so what do I mean when I say you are all loading well let's maybe do a little bit of history first of all I like to ask you how many of you are through a Mac old timers and it sort of real real veteran so I seeing a couple hands Oh a bunch of hands cocoa great well then probably you remember loading URLs like this no well maybe not and and well I also want to say you know it says you know a doc right well Steve Jobs not the only one who's going to do doc minimization tricks their heads these are the jokes people so well of course you know sort of now all kidding aside everyone knows that this is the way we load URLs right no no I mean maybe not well okay so getting back to the real real material of course these are a bunch of URLs this is what we're going to be talking about today this is the there's a level of networking that we're going to be talking about today is really the level of the URL so if you have a URL and you want to use this API well the thing you're going to have is a thing you're going to use it for you have the URL you want the data whether this is the API for you so you start off with the URL this API will help you go out to the origin source whether that be a network file system what have you and get you back the data so if you're a framework developer and application developer this URL loading API is something I think you're going to be pretty pretty interested in and so you might ask well why why a new API you see if you go out on Mac OS 10 well there are many many API for URL loading right cyberdog now it's just so I've got five years I one of these things is not like the other well of course URL access manager in carbon carbon for that well we again we have many many api's and there's but there's really even though we have all of those there is one big reason for developing a new URL loading API and of course that's Safari and when we started developing Safari just about two years ago now well first things we realized as well its web browser URL loading it it's pretty complex I mean there's a lot of things that you have to do in order to work like a web browser in the way that people have come to expect and and really it has to just work all the time there's not there's not many people don't have a lot of patience for a web browser that doesn't get them through to the places where they want to go so it has to just work and so when we started Safari well we knew the URL loading requirements well we it had to support a world class web browser that was our goal right from the beginning with Safari is that this is going to be a web browser that everybody on the Mac was was going to want to use and so in order to get there we had a short list of things that we were going to try to target to even try to hit and just go over these briefly naturally standards compliance is a big one there's a very very long list of rfcs that were related to web technologies naturally the HTTP rfcs figures very very prominently for web browser so we have to implement impo implement that but then of course out on the real world internet well not every site is going to implement every standard to the letter so we had to make sure that that Safari would interoperate with with all of these sites because people want to go go to these sites so we have to make sure that we can get through there and of course there are some real details once you get down to URL loading above and beyond things like you have to do in WebKit and so forth and so we wanted to make sure that we had both standards compliance and real-world compliance and then there were features things that none of those other api's that I listed before really we're going to deliver for us as they stood right there things like caching and cookies things i'll be talking about a little bit later and then of course there's the issue of performance we wanted to make sure that that that you are loading and that the browser was really really fast and and and if i go back to the beginning of the Safari project well when I started on this project I know how to use a web browser but I certainly didn't know how to write one and the first thing that I ever learned about web browsers was this here if you want to make a fast web browser you have to have fast you are a loading nothing else matters if you don't get this right and that was told to me by John Milton you may have seen his talk I think it was on Tuesday it's the first manager of the Safari team and so this was this was where this is where I came into the project and this is what i started doing and you know I we figured that while we were at it while we were at making sure that we had this good performance and the features and the standards compliance and so forth if we go one step further and and hone those api's a little bit make sure there are no WebKit dependencies no GUI dependencies and so forth a couple of other goals we had that we could have a public API usable outside of Safari too you are alluding and so that's what we that's what we did and and just to get back to this performance issue again you know we really do think that it turned out and it was fast and I think you see that in Safari as a matter of fact I think it turned out to be really fast to the point where i'm sure you probably saw the keynote and you saw the g5 and some of the great new technologies that's in there well this api so fast that you know we had some cooling concern so we wound up dividing Safari up into four different thermal zones now so you're going to go home you're not going to know which part of this presentation is the real stuff in which is it which is the jokes yeah well anyway back to the real stuff so we think this API really does work great we do we use it in Safari and now we want you to use it too so that's that this developer conference we're going to be making this available so my job now for the rest of this time is to convince you that it's something that you want to use and whether or not you should be interested and so why should be interested in this API well its API through you if you load URLs if not well you can probably fall asleep I mean you may anyway by time things are over but really this course you are loading URLs is real prerequisite but then if you develop frameworks applications this API is really it's for you it I think it'll be suitable for you and and here's the key point is if you value features more than details if you're going to be interested in every little socket option every little bit that's coming over the network this may not be the right level for you in the stack you may want to get down maybe a little bit lower on but if i said as i said before if you have a URL and you want to get the data and you don't want to do a lot of extra work you want it to work correctly but you don't want to do a lot of extra work I think this API something you might be interested in and then the last point there is whether you use objective c or c c++ sort of both in you know the cocoa and carbon developers should find this api api useful and i want to go and say yes yes c c++ carbon developers you can use this API i won't i won't lie to you the new API is in objective-c but there is no technical barrier to using this in your program you will need to write a little bit of glue but you know here's here's my advice of on this subject is that if you like the features if i do a good enough job convincing you that the features and the api something you want to use just linked with foundation and and start coding and and the good thing is in the in the web kit sdk which you can download from your through a DC there is example code in there which will show you how to do this from a carbon program i even have a demo a little bit later which i'll be showing you briefly but of course to really get into it you need to go and look at that code in the SDK and so anytime that a new API is is is it out and one that affects others so yeah I can I've been in your position before I mean your question you're asked well what changes and what stays the same so let's go through that a little bit the URL loading API for Safari move down into the foundation framework okay and it's now called foundation URL loading API I think you heard that turn of phrase quite a few times okay there's also another existing API in foundation to load URLs and its URL handle and that's superseded but supported so if you're using and its URL handle now in your code that code will continue to work without any change you don't need to do anything however for new code we suggest if nsurl handle with something that was attractive to you I want to convince you to use the API will be talking about today instead there's also a number of existing conveniences in foundation having to do with nsurl just you have an NF URL and you want to get the data for that well those are still fully supported and one of the things that we're doing this is sort of still in progress we're in 3 implementing the internals on top of the new API I think if we do our job right this will be this will be done for Panther release in a stream and foundation is another API it was just the course introduced to this conference that's still fully supported as is CF stream still fully supported but of course those two api's are sort a little bit lower in the stack and they're not they're not going to have the same features like i'll be talking about however they do give you more control in return and so that will be really up to you to decide they're still fully supported as this CF network is sort of the same idea you'll get some more protocol support and CF network if you want to maybe have more control over threading that's your thing again a lower level API use it if that's where you want to come into the stack still fully supported matter of fact I should mention foundation URL loading API uses CF network extensively and so this is still still good api's but again it's still a matter of leveling where you are in the stack URL access manager in carbon however even though it's still available to you it's not being removed from the API removed from the from the system however it's no longer an active development and I probably refer you to the to the dvds there was a networking overview this morning where Becky will rich talked a little bit more about transitioning off old API so you may want to look in your book and look in your dvds and and see a little bit more information about that and of course you could still you can still do it yourself I mean if you want to do sockets and go down to that level you can but that's a lot of work again if you have a URL and what you want the data that's really really going to be a lot of work for you and I don't suggest that instead i would suggest the foundation you are a loading api to my so I I get the big check mark okay and again if you have a URL you want the data you like the features and you don't want to write a lot of code this is this is probably going to be the API for you and so what are the pieces of this API what what are what are the components what are the what is the feature set and so naturally the first part of it and naturally to you are loading API to a very very big part of it is you are a loading but then there's also these other pieces which round out that feature set and hopefully we'll make this API where you know convenience easy for you to use and give you the give you the the right combination of power and simplicity and we'll be stepping through these and doing some good good detail about those so getting into that this first piece URL loading this is really the basic building blocks of all of those other pieces on the LAN that bottom half of that that previous slide so we go go back to that they're right URL loading is the building blocks for all of those pieces under the break so I just want to sort of give us a good grounding and talk about this this you are a loading piece first there are some men components in url loading the concept so I'm going to talk about first and we'll talk about how that really fits into the API we have request-response connection and delegate callbacks you'll be seeing this again and again and again throughout the talk so these are things we really want to get to get a good hold on so URL loading begin with request what is it request well it's request is a URL + load specific data so you have a URL you want to load it but you want you want to specify how it should be loaded so for instance you may want to bypass the cash go back to the origin server pull that data down freshly you may want to add a custom HTV user agent well or other HTTP parameters this would be the place where you would do that in this in this nsurl request object ok so again request is a URL + load specific data so we have a response and a response gives you everything but the data and so will you send a request out you're going to get this response back you're going to be getting data of course but you're also meaning i'm going to be getting interesting metadata that your that your application is probably going to be pretty interested in things like mime type content length or then hdb specific information like whether or not the data should be cached or not and this is how you get this delivered to your to your code and nsurlresponse-- we have a class in the API for this okay connection a connection is a handle to an asynchronous load in progress so if you have a qwest you can create a connection with end start your load it turns out that request is reusable you can go and and create a request create a connection with it go back and modify that request again once you start your connection though that request is yours you can modify a change the url change some of the things and use it again to create another connection okay so that turns out to be really really convenient when in in in real code it may seem like a like a small point now but it really is really very very convenient and so as I say connection ID uniquely identifies a particular load particular request you're sending out and since this since this loading happens asynchronously this connection gives you a a handle for canceling in case you want to stop it before before it's all done and we have a class for this and it's URL connection and so this last piece in this this first set of building boxes these delegate callbacks well so you've got a request you create a connection your load begins well interesting things are going to start to happen there may be going to be getting your response back some data is going to come in and so forth well the way that we deliver that to your application is with with these delegate callbacks okay and so this is for informing you about interesting events and not only informing you but giving you in many cases a chance to take action in your program this is a very very important hook for adding that application specific behavior so that your app can act like it needs to okay and some examples of this is again you've got the response you got some data delivered to you and your load with finished and so we have nsurl connection delegate this is an informal protocol you implement in your app you choose out some of these delegate callbacks and you implement them and you'll get the callbacks when when those events happen again I I just touched on it briefly a moment ago but it's important to to mention that these delegate callbacks are optional there's that there's really a quite a quite a nice list of them however in your program you only need to implement the ones that are important for you that that makes sense for your application and so looking at all these pieces again yet we have request-response connection and the delegate delegate callbacks let me just go back again these are very very important again the important building blocks you'll be seeing them again and again throughout the API when you look at it and then certainly for the rest of the time during this talk here's a here's a small example just to show you again the level at which you would come into this API to go and do some of the work that it knows how to do so you have maybe a custom method in your in your program load URL you have an nsurl and create a request with it and then create a connection with that request and that load starts automatically someplace else in your program implement a couple delegate callbacks and this is all you need to do to start using this API again it gives you that nice level where you have the URL you get the data back and you're moving on to the other parts of your code that that is really probably more interesting to you than doing the actual loading of data and so I'd like to do a little bit of a demo hey demo I could tell you about the demo but it wouldn't be nearly as interesting did the machine go to sleep perhaps yes okay ah there we go ok ok I have a little app here called visible loader let's just let's just run it and what you'll see here is I have a URL bar and I'm just going to poke this the start load button and you see some things happening well what is it that happen I've got this www apple com URL in the address bar and I loaded I just loaded that URL there's the the visible evidence of that is in this window which are these these are the delegate callbacks that I got that's what this application does with its delegate callbacks is it logs them in this window and so you can see I can go around and and and brows brows these these delegate callbacks and and get some nice information about them let's kind of just hop back to the pot back to the code for a second if I can I seem to have lost my aliases so you'll have to forgive me we just quit this for a second and see if they come back no I had a bunch of aliases that I think you have lost well there we go there they are and so here are the delegate callbacks this application implements an you'll see in just one of the you know a simple example is I received data and all that I did in this app application was I updated the progress indicator and I put a little log message in the window so that we can go and look at it now naturally in your application you know is in safari for example what we do as well we take that data we feed it off to the to the HTML rendering engine and so this is the way again that you begin to hook in your code into this new API and again it just you know illustrates that this API is not it's not a black box it gives you a good amount of visibility in other words you just don't throw URL over the wall get some data back and that's it try to give you a good amount of control over over what's happening as it as it's going on okay go back to the slides please so again those four pieces then been over them and over them again the basic building blocks for URL loading the i/o is asynchronous and there are a bunch of these optional delegate callbacks that you get ok so now using this as a foundation let me go on and talk about another piece of the API which is URL file transfers excuse me and so this is very very similar to you are a loading however it gives you some nice features for downloading content instead of just like to the maybe the innards of your program or something just going to download that URL on to disk and there a couple extra delegate callbacks you might imagine to help you do that and uploads are coming soon and so we take this same picture that we had before a download comes into the middle there and takes the places connection but everything else stays the same we've got this class and its URL download to go into the place of nsurlconnection but really the way that's the that the program works is really very very similar and I have another brief demo of that what I wanted to do for this is illustrate a carbon a carbon example and so I'm going to run this and you'll see that i'm going to go HTTP i'm single threaded when it comes to typing so you'll have to excuse me max calm and and download and you'll see i'll get a little prompt so and probably just pride on the desktop would be great so go and do this little download and you see I've got the file there and so you know again to illustrate you know we saw the sheet come down this is a carbon program as well as I can show you there's a slightly slightly modified version of this it's actually a nun hacked up version is actually what it is which is going to be in the the developer STK and you'll see that again it's just a bunch of delegate coba it's actually a few more than the other program that we looked at and again it gives you a a a good amount of control the side destination with suggested file name is what is the hook that we use to drop that sheet down so again you get a good amount of control of things as as they're going on and then as you can see down here this is a little C++ code so this is an objective C++ file and it's a little indication of the kind of glue that you'd have to write to get from get from your C C++ code over to where you can use this use this API okay good I'm going to clean my mommy always told me to clean up after myself so there we go okay good so if we can go back to the to the slides please yes demo and so here seen this picture before these are the basic basic building blocks of the API loading file transfers and delegate callbacks so now to go on and talk about yet another piece content caching well what is this for well after we download a URL we store the content locally I don't think this should be news to any of you makes furture for future requests for the same URL go faster now the interesting part I think about this about this portion of the API is that it just works automatically you don't have to do anything you don't have to call a method or set a flag or anything well I want caching no it's just going to happen for you automatically it's going to go faster if it can if it can help you to go faster it will how end but I should also point out that there is an API to provide direct access to the cash and its contents if you wish and some of the features of this this portion of the API first there is I like to think that the that this API has presents a good HTTP cache smarts there's a there's a lot of texts in the RFC for HTTP about caching and we've implemented that we've gone through gone done the work to implement that here and so so that when you're interacting with this API to go and get content for HTTP servers it's going to work the way that you want with regard to caching and so that's that's that's a ones that being a bunch of work that you don't have to do and the benefit is that you'll get the correct combination of correctness and speed another big addition to this API is is disk caching which is I think a very nice very nice feature so that your cash will be persistent across multiple runs of your application and then there's some other things configurable policy for a quest time like I said before is it bypassed the cash is perhaps an option there's also some other other policies which I'll talk about in a little bit and then there's as you might imagine a delegate callback for response time when things were going to get written into the cash now unlike the api's that I talked about before request-response etc you need to ask yourself well is this a portion of the API that I really need to use and well I would I would you know I would answer that by saying well if you want the cash to work in the background if you want it to help you make your program go faster but you don't really want to know about the details so much you're not going to need this portion of the API again it just works automatically and you'll get the benefits without having to do any work however you'll need this API if you want say custom cash policies for different loads or even surely direct access to the cash you'll need this API and so here the building blocks for for this part of the API cash cash response and cash policies just go through that the cash is actually the single concept but it turns out to be a stack of memory cache and disk cache you don't get to see them really separately they're actually some API methods which will operate on one of the other however when you ask the cash for something there's there's no there's no way for us to even a report to you through the API oh this came from memory this came from disk okay but again it works transparently if you're using just the request response API you will you won't be involved in in interactions with the cash as you might imagine it will look in memory first since if it's in memory it can be returned to your program much faster and then look on disk which naturally has much much more storage to look for information I should say that there is a you can configure the sizes of these caches and you can configure where the disk cache will live in case you want to say ensure that it was on a local volume or something like that and again of course it can be accessed directly through the API and we have a class for this nsurl cash cash response a cash response stores the URL data and the metadata and so it wraps in nsurlresponse-- it wraps an NS data and when it comes time to disk caching that's that object is just realized right out to disk in a file you may have looked in your Safari cash on disk then you see a bunch of files with cryptic cryptic names well what those are serialized and cached responses actually technically they're serialize and it's cached URL responses okay and then the last portion of this API is cache policy controls whether the cache data is returned for a URL request and we have several policies here you get those good HTTP cache smarts that I mentioned before by default when you're using HTTP but you can also say well by cat bypass the cash in case your application may have a reload button very very simply simple for you to do that and then there's also some offline behavior if you know that you're not connected you can specify look give me this data from the cash even if it's expired if it's stale I just want it because I can't go and refresh it right now and so this is also very useful for some other applications we have an enum for those constants and so I just wanted to show you a very brief example of how to access the cash directly get the shared URL cash you have a string representing URL create a URL with it create a request with that URL and then you can just go and ask this this shared cache object for the out for the object that would map to that request and then you can just get an N its data back from that and then go and do something interesting with the data once you get it and so just with a few lines of code you can take advantage of the direct access cache API and so I would like to do a demo I have a sleepy computer today it looks like could I get a demo thank you and so here's a little app I called the disk cache inspector and and what this does is it's gone through and it's looked at a provider list of all of the files in the Safari cash and so here they are and then we can do some some interesting interesting things with it I think they're interesting at least is that we can go and and give a view of of what the content is in the cache and not only not only images you could see that in the case of an HTML page I've actually got the HML this is is actually is what is in the cache and so what you can do with this program is you can su to root and see what other people have in their disk caches which is kind of a you want to do that okay and so and so there are some other things here too which I think are pretty interesting here's uh if I can do this oh yes here's a sum of actually much of what is in an nsurl response you see there's HTTP specific information in there that's what's in the cash as well and then there's also quite a bit of information that is comes into use to implement this good cash smart that I mentioned so a lot of this information comes into account when you send out a request the cash is consulted and the engine has to decide am I going to use this cache data for this request or not or am I going to go out and reload from from the network or for the really from the network file URLs typically aren't cash okay and so this is again an example of what you can do with the the direct access cache API in a little example of of what why oh that's a good one what winds up what winds up being in there okay okay okay okay the slides back please okay just to summarize again we've got cash policy's cash cash response the cash stores URLs locally makes things go faster if it can and again it has this nice feature where it'll just work automatically if it can and so fitting this in to the rest of the rest of the pieces of the puzzle are we filling those in and so we've got cash cash fits in right there and so going on to the next peach HTTP cookies I think probably most of you if not all of you know what a cookie is well when you go out to a website it'll send you back a small packet of information that then when you go back to that website you'll send back that little packet of information back to that server every other time you access it in the future and so enables a lot of ecommerce websites website logins rely on this a lot another great part I think of this API is that again it just works for you automatically so we've got a lot of cookie machinery that'll just kick in whenever you do HTTP if you need cookies it'll just they'll just be applied for you but again this API provides you direct access if you want some more control and so the features of this API we've got persistent cookie storage so that you have your you're a cookie cookie file on disk another another interesting part of this is that the cookie storage is shared per user so each user will have their own cookie file but it's shared among all applications that that user will use and so if they get some cookie data from say safari they'll be able to use that cookie data in Sherlock and you won't have to do anything and so but additionally because cookies there are some security some privacy concerns we do have configurable accept policies and then another piece that we worked very hard on in the cookie API was to was to interoperate some real world compliance there to make sure that when site send its cookies that we can parse them and read them and use them as the website developer intended there really isn't a good standard here it really is just their law of the jungle and and we've really really tried to make sure that we we have a good interoperability with what you'll find out there in the internet and so again do you need this portion of the API well if you want cookies in the background without worrying about the details you don't you can just sort of let this work for you and do its good work without having to delve into the details however if you want to control cookie except policies or get direct access to the cookie store then this is a portion of the API you'll need to learn a bit more about cookie cookie storage cookie accept policies these are the three three pieces of this API and so cookie as I just said this little nugget of information that is sort of exchange between your program and a server these are created automatically and sent back automatically and again there's extensive rule checking for these NS HTTP cookie we have a class in the API for this cookie storage cookies are shared on disk as I said and are shared among processes this class will manage that cookie file it'll actually do the do the work of parsing out this cookie data and then this is probably we're going to come in and inspect set remove cookies as you wish in your application we have a class for this NS HTTP storage and cookie accept policy accepting cookies is governed by this setting there's actually three different settings always accept always reject and then accept that only from the same host and this happens very often you go you go to site a but add server site wants to set a cookie on you when you go to that site you can set it so that that cookie would get rejected but any cookies from the site that you navigated to will actually get accepted and so we have a set of constants for this as well now in Safari yeah you've probably seen this window here it may be a little bit hard to see but but the the second sort of savage sort of check boxes on the top stead of radio buttons well that's the cookie except setting dialog in Safari it's going to be in the security the security and when the user goes and checks that you can see you know he's just a quick example of of just a few lines of code that you'll need to go in and and and actually implement that setting this is just actually really just copied right out of right out of so far just to two other case statements like the one that what that is listed there and and you're done so again there's sort of EV the economy of coding that you're going to need to do to use this API and get to get the features out of what's in there and we've really really concentrated on that and so again here are the pieces of this API cookies help with the website logins e-commerce and are shared among processes and just work for you automatically and so we dropped that piece into the puzzle and so moving on authentication authentication actually proving your identity to a software system and in most cases for websites this means you know this sheet will drop down and you're gonna need to type in your username and password I'm sure you've probably many of you most of you have seen this dialog in in Safari and so this portion of the API provides your hooks for a custom UI like you see in Safari however point out that there are actually no GUI dependencies you again there are no WebKit dependencies there's there's there's no cocoa there's no AB kit dependencies in this API so we have to sort of work it out so that would work so that would happen and there's a hook for providing custom authentication schemes and there's ask once capability integration with keychain and so if you're just interested in loading URL through the WebKit API you don't maybe you want to come down to this level well naturally this portion the API won't be for you or if you don't need to access protected data however if you do want to you know see that she dropped down or have functionality similar to that you're going to need to learn about this portion the API the authentication piece or if you want to develop a custom custom user interfaces these are the pieces mercifully I'm not going to go and talk to you each one individually just as you know these are the pieces that we have to represent usernames and passwords places with you want to authenticate to individual authentication challenges and so for they're all they're all in this portion of the API and now I'd like to do a brief demo okay so what I've done here is I I just went out the other evening and I I found this site on the net that does a lot of provides a lot of test pages for HTTP authentication I'm just going to go up on this very very first one and get the sheet dropping down this is the authentication API in Safari being used i'm just going to log into this site and you'll see that i get access only two rows basic auth it's just a little test page okay and so you see Safari using this this API then I'm going to do another another example like the going to the same site I like to call this that 70s demo hey there like the I did the nice amber you know I I couldn't be the amber or green I couldn't decide well anyway this is an example of using authentication from from a command-line application to see here I didn't even take the trouble of doing hiding the password but you can see again you just get the output printed to the terminal in exactly the same as showed up in Safari just showing that again this API has you can use it from command line applications you don't need to be writing a GUI program to get to derive advantage from it so so with that back to the slide please it's authentication again providing access to protected data asked once with the keychain and no GUI dependencies as was illustrated and so and so and so authentication fits in fits in right there going into the next piece custom protocol so let's say you have an application and these protocols HDPE HCPs have to be file and about don't suit you you have gopher you have some custom protocol that you want to implement in your application well this will be the API that you use to to develop your own and I think the really really strong part of this API is that there are there's no there are no secrets there's a very very clean interface to the other parts of the subsystem is your it winds up being the same interface that those built-in protocols that we actually wind up do providing to same API that those that those protocols use your protocols our peers to the one that ship on the system I think that's a really really strong part well actually do you need this API well if you're not going to be developing a custom protocol you don't then if you are well you do and just two pieces here protocol and protocol client this is what actually does this is really you know in some ways this the classes that implement this this protocol concept they're really one to being the engine of the of the API wanting to wind up doing the real work to go out and load load a URL in a protocol specific fashion many many times these map to a scheme like HTTP and then they really do work like in many ways like plugins I mean there that you can you can uninstall and reinstall actually even while the application all the application is running and they just must be registered in order to be in order to be used and we have nsurl protocol is the class for this in the API and then we have protocol client which is the piece that provides the interface to the URL loading system and in some ways you can think the whole engine is over here and if you are all protocol instances are over here and you use this protocol client interface to talk back to the system from from from your protocol and so there's no secret API and there's this one way communication once a protocol is created it's the responsibility of the protocol to drive the URL loading process and tell the URL loading system about things that are happening in protocol specific protocol specific things I mean to do with a load and nsurl protocol client is the API piece for that and so here's just a very very brief example of things that are in the protocol client interface you'll notice it's actually these turn down and when maybe get the SDK and you look you'll notice that these pieces are actually trying to be very very similar to what's in the delegate callbacks again these protocols are actually doing the work that drive they'll drive the load of your URL and so you know when interesting things happen they tell the system and then the system goes and tells you in your code and then actually implementing a protocol you only need to do a few things you need to implement a small small handful of methods to just go and implement your own your own protocol and have it be a peer of all of the others and as a matter of fact this is a this is a snippet a surprise it's a good good majority of the code that's actually in the about protocol in Safari and I just highlight out just a a couple of lines to show that this is the protocol interface the about protocol and it's driving of the load back through to Safari and you see about protocol never never fails it's always always succeeds did did finished loading at the end and so protocol Klein protocol again no secret api's your protocols are peers is a very very clean interface to the rest of the system and so dropping that dropping that piece in there and so I'd like to do just another another brief demo and I'd like to just point out a feature in Safari which I don't know if I if if if all of you have seen but this is the activity window and although you know once you know in a real program it's not you know it's never quite as straightforward as we try to make it up here on onstage but but really what what lines up happening in this activity window is these are all of the URLs that you loaded and and and really what winds up happening each entry in this list when that winds up there as a result of one of these delegate callbacks from the URL loading system that URL got loaded and eventually that winds up getting reported through the the user interface in in Safari and so this is just again otta yet another example of how delegate callbacks are used I'd like to do another another small demo here to this is one I was not planning on doing but I must have spoken quickly but this is kind of neat I think and so what I'm what I've actually done is actually now I have three versions as far let's just go with two versions of Safari and so I'm going to do is rearrange these windows here and and in both i'm going to show the cookie list so that's the cookie list for this window and right and then the is the cookie list for this window that's what i'm going to do just to it just to make it easier easier to see i'm going to remove all of the cookies from both applications that what what you've seen already is that those two copies of Safari to WebKit clients to nsurl foundation API clients they're cooperating on the cookie store you remove the cookies from one version of Safari and the other version of Safari its window odd just automatically updates with new information about a change in the state of cookies and so if I go pick one of these and go back to a site where cookies get set again you'll see that as soon as I click in that other window it updates redraws and shows that cookies get set and in that window as well so again an illustration of that cookie API and and the cooperation between processes running belonging to a single user okay great may have the slides back please and so to wrap up this is a roadmap some of these conferences actually half of them the first two I see have already happened please going to go back and review on DVD the open source talk we used a lot of open source in in WebKit and Safari there's actually no open source it turns out in this portion of the API is still implemented by Apple but if you're interested in Safari technology in general that's a talk you might be interested in Safari technology in web standards talks about if you're a website developer you want to develop content that's going to work well in Safari if you're just interested in web standards in and apples implementation stance towards standards the second one advanced foundation URL API as well that's this talk so you saw it that's that's all there is to see and then tomorrow I I really urge you to go to the if you're interested in Safari technology go to that last one tomorrow at 9am advanced WebKit api's if you've seen those demos of wiring things up with WebKit well you really go down a step lower and see a little bit more about what's about what's under the hood and then yes another session tomorrow afternoon internet technologies developing web services using web channels some sherlock technology Mac os10 networking api's again I mean if you if you you know you saw those checks and exes before I mean I think it's it's probably you know if you're not familiar with the API is it's probably a pretty tough choice for you to decide which of these you are loading api's do I want to use well I think that that session will give you some more good information about that and then tomorrow afternoon see if network in depth will talk to you more about see if network and then I also encourage you to come tomorrow at ten-thirty to the feedback form where I'm because you're going to have an opportunity now to ask some questions but tomorrow you can you know come and give us some more feedback about this API and and networking as well and if you think of something now or if you have other feedback a little bit later John Bell NZ this the email address on the screen is the is the person to contact for more information and to get further further feedback and so here's some some other information about about these api's there are some I think some very very nice the documentation people did a really really nice job going through and sort of cleaning up what we did and documenting it in such a way that you folks can understand it hopefully so I I refer you to this documentation and then really if you want to get into this API you want to get into this API in the WebKit API really urge you to go and start working with this web kit SDK again I should probably it's been mentioned before but just to make sure that everyone knows that the all the code that you need to do the applications like I wrote here today and and the ones that you've seen with WebKit if you have Panther you have everything that you need it's installed on the system if you have a Jaguar system and you've installed Safari 10 everything is there on the system you you have everything that you need however there's some other examples and such that are really only going to be in the SDK and so I still do urge you to go out and get it