I am just wondering how facebook manage requests to "my profile page" and "home page" and some other pages that seem to reload just some content.
For example when I am on "my profile page" on facebook, i Hit the home button and the top bar button and chat panel on right side remain intact (they are not reloaded). I have monitored XMLHTTPRequest in webkit console and no ajax is generated, so its not Ajax (i think). Otherwise, if FULL http requests are generated when clicking those links, I thought the full page must be reloaded, I am right? So I have no clue how is this handled. Can you give me a hand please?
Thanks :)
It's a type of performance optimization called "quickling", they also use a "pagecache" strategy to reduce the data from server. In the lower level, it depends on javascript perform as a LinkController, which delegate a hyper-link click event and then send an ajax (or use iframe) to request the pagelet data from server, the response will be a json-formed data structure, then javascript will insert the content of current page. Uri in your address bar can be dealled with the hash change event in old browsers and H5's History API (pushState) to manage the history record of browser.
Related
The question is probably easily misunderstood, so I'll go into more detail:
I am trying to automate a task in a certain (very outdated) browser-based idle game that is written in PHP in order to polish my portfolio with a little more variated projects.
I used DevTools to reverse most of the requests and wrote a small C# Request wrapper to test them. I can get most of the actions I want to work, using the respective ajax get requests and the correct cookies/headers - not really part of the problem.
Example:
Attacking an enemy:
https://somebrowsergame.com/game/ajax.php?mod=location&submod=attack&location=3&stage=2&premium=0&sh=****mysessionhash****
Making a GET request to this URI with the correct headers and cookies, I can perform the in-game action programmatically and successfully from my C# console application and see that the fight has taken place when visiting the site in the browser.
The problem:
When monitoring all requests after clicking the "attack" button, via DevTools, even with preserve logs enabled, I don't see any redirects or way of determining how my browser gets told where to navigate to.
Findings
I found out that the button calls a javascript function attack() in its onClick event and tried debugging the javascript in DevTools in order to find out where somethign happens (such as setting document.href or smth), but when Debugging I ran into a seemingly infinite loop of setInterval handler and setTimeout handler in the call stack.
I also cleared the Network tab after the onClick event (and after the ajax request which I could find during Debugging) but the only request/response I got was the document GET request for the final page, no request telling my browser which site to navigate to.
Monitoring requests
The request made to initiate the action (via button click on website or ajax GET request as outlined above)
The document response / site navigated to
What I want to know is how my browser got told which site to navigate too, as the request URI for the document request (getting the html of the target page) has a parameter generated on the server side (logId)
I have also used "All" request types in DevTools, as well as negative filters when monitoring requests but never was I able to see how my browser knows which page to navigate to. I tried with source breakpoints at "beforeunload", tried inspecting the javascript source connected to the onclick event of the button (which didnt give me anything, as the js is minified and barely readable - i am not even sure if the navigation is done via window.target.href) and googled this question in all possible wordings which lead me nowhere
I am not too versed in web development, but I am sure my browser has to be told where to navigate to in some fashion after clicking that button?
I was reading up on ajax and how it empowers us to exchange data with a server behind the scenes and consequently avoid full page reloads. My confusion lies here, I don't really understand what full-page reloads mean. I think it's probably cause I've been working with ajax/react since the start I guess and have not really seen any webpage of mine fully reload when I access stuff from a database or an api.
It'd be great if someone could explain what they are and why did we need them before ajax?
A full page load is where the entire page is downloaded from the server. A page typically consists of several sections: header, footer, navigation, and content. In a classic web application without AJAX, a user clicks on a link to another page, and has to download the full page, even though only the main content is changing. The header, footer, and navigation all get downloaded again even though they don't change.
With AJAX there is the opportunity to only change the parts of the page that will change. When a user clicks on the link, JavaScript loads just the content for that link and inserts it into the current page. The header, footer, and navigation don't need to reload.
This introduces other problems that need attention.
When AJAX inserts new content into the page, the URL doesn't change. That makes it difficult for users to bookmark or link to specific content. Well written AJAX applications use history.pushState() to update the URL when loading content via AJAX.
There are then two paths to get to every piece of content. Users can either load the URL containing that content directly, or load the content into some other page by following a link. Web developers need to test and ensure both work.
Search engines have trouble crawling AJAX powered sites. For best compatibility, you need to employ server side rendering (SSR) or pre-rendering to serve initial content on a page load that doesn't require JavaScript.
Even for Googlebot (which executes JavaScript) care must be taken to make an AJAX powered site crawlable. Googlebot doesn't simulate user actions like clicking, scrolling, hovering, or moving the mouse.
Content needs to appear on page load without any user interaction
You must use <a href=...> links for navigation so that Googlebot can find other pages by scanning the document object model (DOM). For users, JavaScript can intercept clicks on those links and prevent a full page load by using return false from the onclick handler or event.preventDefault() in the click handler.
If you carefully notice facebook, you will understand that the when you visit one page to another then the whole page is not refreshed or redirected but the URL changes when navigating to new page. It is more clear when chat windows are open, they remains static during page loading. As other website does this by using the # but facebook does not.
There is another example came to me: http://www.davidwalsh.name/. Visit the site and open other pages within their site and you will understand what I mean. Don't forget to notice the URL change.
How they do this?
Added More: I want a way that the page content will be loaded with ajax, change the URL for bookmark feature but when changing URL it should not reload / refresh the page by not using # (hash).
You have two questions:
For the URL change you can put the path instead of the # in the href property of the anchor (e.g /otherlink).
For opening the chat or opening some div does not require to send it in the url, its the onclick event on the div and its expands. Also the chat remains open may be thay set cookie or flag when the chat is first time opened and checking and changing the chat with flag they are setting.
As suggested by #andytuba
For Facebook, Google "hash navigation ajax".
For DavidWalsh, google "history API".
I have a very strict requirement to use POST to pass in request parameters to my application upon entry. Once entering the application (page1), entering form information and continuing to the next page (page2) via a commandButton, the expectation is that the data will be posted and later read from a session scoped manage bean. All works well except when using browser back on page2 to navigate back to page1.
I have tried adding a redirect tag on the navigation rule that navigates from page1 to page2 to no avail. I have also tried this implementation of the Post-Get-Redirect pattern (http://balusc.blogspot.com/2007/03/post-redirect-get-pattern.html). Am I missing something obvious here?
Abel, the scope of page1 is request.
The solution we came up with which is no means ideal is to disable browser caching on the previous page. What this means is that whenever you refresh the page using the browser refresh button or click the browser back button, the browser will indicate that the page is expired and prompt a warning asking whether you want to re-submit the request.
We do have a work around which is to provide navigation buttons within the webpage but the idea was to support browser back. This would be easy using GET parameters, but POST provides additional complexity which we have decided to mitigate by by providing our in-house navigation buttons.
I am implementing a web application using ASP .Net and C#. One of the pages has a requirement that it always needs to be fetched from the server, rather than from the local browser cache. I have been able to achieve this.
We have a back button in the application, which simply invokes javascript:history.back() method. The problem is that when the back button is clicked to navigate to the page which is always to be reloaded from the server, the browser displays a "Web page expired message".
The intent here is to force the browser to reload the page rather than display the web page expired message.
Any help would be highly appreciated. Thanks a ton in advance.
You will probably need to change the implementation to make the browser load the URL explicitly:
window.location.href = 'http://....';
instead of invoking the back button, since the intention of the back button is to get the last page from the cache.
(If browsers would not act that way, they would re-send your form data multiple times when using the back button during a registration process or similar.)
You mean you want to control browser behaviour, which is not possible. I doubt you can solve it that way. You could set the expiration time to a small value (1 minute perhaps?) so that the page is still valid if one navigates back quickly.