Seaside by default points example.com/myapp to whatever application is registered at myapp. I'd like to have a core application that can also handle these links, or some other way of handling these links.
So far, I have a home application that is also registered as the default application, so http://mydomain.com will resolve to it, but if I generate a link, like http://mydomain.com/more-info, Seaside tries to resolve an application registered at more-info. What if I want my home application to handle the link? Or handle it in some other way?
I'm hosting Seaside with Apache, so I could use Apache's URL rewriting engine to rewrite http://mydomain.com/more-info to http://mydomain.com/home/more-info, which would be handled by my home app.
Is there a better way to do this? Also, if a link exists to an explanation of the Seaside request/response lifecycle, that'd be sweet.
What you are trying to do is not common practice in Seaside applications. If you want to generate a link from one page to another page in your application, you generally use a callback attached to an anchor:
html anchor callback: [ self call: moreInfoComponent]
In such cases, you do not care about how the url looks like and Seaside generates the url for you. Such generated urls never have a nested structure but use parameters.
More information on the Seaside request/response cycle can be found in the online book (chapters "Fundamentals" and "Sequencing Components").
However, if you indeed want to have such a nested url (to make urls bookmarkable), there are different approaches, depending on what you actually want to achieve. You can either take a look at the approach for handling expired sessions (in the book) or at the Seaside-REST package.
Btw, the mapping of urls to applications happens through (instances of) WADispatcher. If you inspect the result of the following expression, you can see the dispatcher tree of Seaside. It's entirely customizable by adding new applications, dispatchers, etc...
WAAdmin defaultServerManager adaptors first requestHandler
Hope this helps you on your way...
Related
I'm trying to comprehend the concept behind MVC and URL routing. I understand that it's good to seperate your code, hence MVC, but fail to understand the idea behind the URL router!
Instead of having a lot of rewrite rules in htaccess, I send all traffic to router.php, and in this page I have an array with page urls, and its corresponding PHP controller.
To keep it simple, I just include the controller, where the output finally is generated, however having seen lots of other practices, I'm afraid that im doing something wrong, or bad in some way..
Can someone please enlighten me, how to do a good, but simple URL router? Is it okay just to include the controller, which then generates the output? Perhaps someone has some information that describes the subject in details (something understandable for a beginner)
Thanks in advance
There are lots of ways to do URL routing. Some are client side like with backbone.js, others are server side. Doing it with .htaccess is one way, another is th way you are doing it by having a prerequisite path that is is either a hard path, or a regular expression that you parse and figure out where to send it. None of them are 100% right or 100% wrong, it's all preference, and it sounds like you are doing just fine with a route file.
For more information on how different frameworks do routing you should read over the docs on routing for CodeIgniter, and Symfony frameworks to see 2 different styles of server side routing, and then maybe look at the backbone.js framework for client side routing just to see the similarities and differences.
The router in the MVC concept decides which controller it has to load when a user requests a page. E.g. a user requests example.com/something/very/important, the router would now look for an action which is mapped to this route and execute it. There are different methods how you can accomplish that (simple include, instantiating a class and running a method etc.) but the most simple and still powerful solution I came up with is creating a separate class for every action. I've written a little article on that matter, since I've been asked this question several times, you can have a look at it here: Writing a simple and fast mvc router with PHP
The ASP.NET Routing module is responsible for mapping incoming browser requests to particular MVC controller actions.
Routing is a pattern matching system that monitor the incoming request and figure out what to do with that request. At runtime, Routing engine use the Route table for matching the incoming request's URL pattern against the URL patterns defined in the Route table. You can register one or more URL patterns to the Route table at Application_Start event.
I'm using urlrewriteFilter (org.tuckey.web.filters.urlrewrite.UrlRewriteFilter) to forward pages like www.mysite.com/myname to a Struts2 action. The action is mapped up in sitemesh, and it works properly.
But now I want to keep the same URL but apply another decorator to the page, based on whether the user is logged in or not.
I'm using AppFuse-stack Struts2.
Ok - since no-one else looks like having a go.
Sitemesh selects the decorators based on the incoming url string, so to have different decorators you need different urls depending on the login status of your client. AFAIK Sitemesh uses the entire Url string so this includes parameters so you might get away with appending ?loggedIn="true" or ?loggedIn="false" and map the decorators on this. However this doesn't help with POST requests.
Another way to do it would be to create two Struts packages - one for logged in users and one for anonymous users so your actions will have different paths and then map on the path part of the Url.
I don't know how practical this might be in your scenario, but a third option maybe to have one common decorator and control the layout via seperate stylesheets which you could control via a test in your jsp.
HTH
Regards
Not long ago I came across this website: http://www.danasoft.com/
This websites provides dynamically updating signatures which are pretty cool in my opinion.
There is just one thing that I don't get and would really like to know how to do.
Here's a direct link to an image on the website: http://www.danasoft.com/vipersig.jpg Try refreshing. Notice it changes? How do I achieve that? How do I have a direct link to a file like www.mypage.com/thing.jpeg output different images each time?
Basically, the URL is not actually retrieving the file directly each time, but rather the server is intercepting that URL and serving a (possibly random) image from a larger set of images. Depending on whether the server is running Apache, IIS, etc, the implementation could vary... This could also probably be achieved with the MVC routing engine by defining a custom route handler for URLs ending in '.jpg', but I'm not actually sure.
EDIT:
See this discussion for more detail on the MVC implementation.
So Google takes:
http://www.mysite.com/mypage/#!pageState
and converts it to:
http://www.mysite.com/mypage/?_escaped_fragment_=pageState
...So... Would be it fair game to redirect that with a 301 status to something like:
http://www.mysite.com/mypage/pagestate/
and then return an HTML snapshot?
My thought is if you have an existing html structure, and you just want to add ajax as a progressive enhancement, this would be a fair way to do it, if Google just skipped over _escaped_fragment_ and indexed the redirected URL. Then your ajax links are configured by javascript, and underneath them are the regular links that go to your regular site structure.
So then when a user comes in on a static url (ie http://www.mysite.com/mypage/pagestate/ ), the first link he clicks takes him to the ajax interface if he has javascript, then it's all ajax.
On a side note does anyone know if Yahoo/MSN onboard with this 'spec' (loosely used)? I can't seem to find anything that says for sure.
If you redirect the "?_escaped_fragment_" URL it will likely result in the final URL being indexed (which might result in a suboptimal user experience, depending on how you have your site setup). There might be a reason to do it like that, but it's hard to say in general.
As far as I know, other search engines are not yet following the AJAX-crawling proposal.
You've pretty much got it. I recently did some tests and experimented with sites like Twitter (which uses #!) to see how they handle this. From what I can tell they handle it like you're describing.
If this is your primary URL
http://www.mysite.com/mypage/#!pageState
Google/Facebook will go to
http://www.mysite.com/mypage/?_escaped_fragment_=pageState
You can setup a server-side 301 redirect to a prettier URL, perhaps something like
http://www.mysite.com/mypage/pagestate/
On these HTML snapshot pages you can add a client-side redirect to send most people back to the dynamic version of the page. This ensures most people share the dynamic URL. For example, if you try to go to http://twitter.com/brettdewoody it'll redirect you to the dynamic (https://twitter.com/#!/brettdewoody) version of the page.
To answer your last question, both Google and Facebook use the _escaped_fragment_ method right now.
When I look at Amazon.com and I see their URL for pages, it does not have .htm, .html or .php at the end of the URL.
It is like:
http://www.amazon.com/books-used-books-textbooks/b/ref=topnav_storetab_b?ie=UTF8&node=283155
Why and how? What kind of extension is that?
Your browser doesn't care about the extension of the file, only the content type that the server reports. (Well, unless you use IE because at Microsoft they think they know more about what you're serving up than you do). If your server reports that the content being served up is Content-Type: text/html, then your browser is supposed to treat it like it's HTML no matter what the file name is.
Typically, it's implemented using a URL rewriting scheme of some description. The basic notion is that the web should be moving to addressing resources with proper URIs, not classic old URLs which leak implementation detail, and which are vulnerable to future changes as a result.
A thorough discussion of the topic can be found in Tim Berners-Lee's article Cool URIs Don't Change, which argues in favour of reducing the irrelevant cruft in URIs as a means of helping to avoid the problems that occur when implementations do change, and when resources do move to a different URL. The article itself contains good general advice on planning out a URI scheme, and is well worth a read.
More specifically than most of these answers:
Web content doesn't use the file extension to determine what kind of file is being served (unless you're Internet Explorer). Instead, they use the Content-type HTTP header, which is sent down the wire before the content of the image, HTML page, download, or whatever. For example:
Content-type: text/html
denotes that the page you are viewing should be interpreted as HTML, and
Content-type: image/png
denotes that the page is a PNG image.
Web servers often use the file extension if the file is served directly from disk to determine what Content-type to assign, but web applications can also generate pages with any Content-type they like in response to a request. No matter the filename's structure or extension, so long as the actual content of the page matches with the declared Content-type, the data renders as intended.
For websites that use Apache, they are probably using mod_rewrite that enables them to rewrite URLS (and make them more user and SEO friendly)
You can read more here http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html
and here http://www.sitepoint.com/article/apache-mod_rewrite-examples/
EDIT: There are rewriting modules for IIS as well.
Traditionally the file extension represents the file that is being served.
For example
http://someserver/somepath/image.jpg
Later that same approach was used to allow a script process the parameter
http://somerverser/somepath/script.php?param=1234&other=7890
In this case the file was a php script that process the "request" and presented a dinamically created file.
Nowadays, the applications are much more complex than that ( namely amazon that you metioned )
Then there is no a single script that handles the request ( but a much more complex app wit several files/methods/functions/object etc ) , and the url is more like the entry point for a web application ( it may have an script behind but that another thing ) so now web apps like amazon, and yes stackoverflow don't show an file in the URL but anything comming is processed by the app in the server side.
websites urls without file extension?
Here I questions represents the webapp and 322747 the parameter
I hope this little explanation helps you to understand better all the other answers.
Well how about a having an index.html file in the directory and then you type the path into the browser? I see that my Firefox and IE7 both put the trailing slash in automatically, I don't have to type it. This is more suited to people like me that do not think every single url on earth should invoke php, perl, cgi and 10,000 other applications just in order to sent a few kilobytes of data.
A lot of people are using an more "RESTful" type architecture... or at least, REST-looking URLs.
This site (StackOverflow) dosn't show a file extension... it's using ASP.NET MVC.
Depending on the settings of your server you can use (or not) any extension you want. You could even set extensions to be ".JamesRocks" but it won't be very helpful :)
Anyways just in case you're new to web programming all that gibberish on the end there are arguments to a GET operation, and not the page's extension.
A number of posts have mentioned this, and I'll weigh in. It absolutely is a URL rewriting system, and a number of platforms have ways to implement this.
I've worked for a few larger ecommerce sites, and it is now a very important part of the web presence, and offers a number of advantages.
I would recommend taking the technology you want to work with, and researching samples of the URL rewriting mechanism for that platform. For .NET, for example, there google 'asp.net url rewriting' or use an add-on framework like MVC, which does this functionality out of the box.
In Django (a web application framework for python), you design the URLs yourself, independent of any file name, or even any path on the server for that matter.
You just say something like "I want /news/<number>/ urls to be handled by this function"