Using ajax request in Google extensions - basic knowledge ? Performance - ajax

I am creating google chome extension and everything is fine, but i need to know the way to use ajax requests more freely, it should be in the same domain (request) or in the file of the extension directory.
For example i have tried :
var heroPage = "";
$.get('/hero.php', function(data) {
heroPage = data;
});
var townPage = "";
$.get('/town.php', function(data) {
townPage = data;
});
And then i try to use the data in the mouseover listener, and the first one works every second time, but the second does not work at all...it may be something with some limitations or etc.
Is there a way to use for example php file with requests in chrome extensions (in the extension directory), or use some kind of different requests or in the different way ?
I need to get at least 5 requests on page load or even near it and store some data in local-storage or etc., and just cant make it work...
Thank you for you help ! answer will be selected for those who is helping for points ;)
Basically what i need is to fetch infromation from webpage html and store it in local-storage but to fetch from few pages at almost same time. ?
Answer to one of the answer and maybe more clear explanation :
Hey thanks for answer but it was not what i meant, maybe i did not explained it clearly. What i meant is : I am having a problem with the link you send with http request (because i am doing like so now) that it works only with one request per some time or etc. and i need to fetch html from five pages. The second thing i understand that php needs to be on the server with apache and etc. i was jsut thinking about overcome to this problem, maybe if i would store php file on my server, and make one request to it, and that php file would make more http requests to where i need and it will returnev erything in one data to the js file. I just need a way get five www html websites into variables on my extension at almost same time , what is the better way to do it ?
someone ?\?

First, let's clear up a thing or two. Files fetched from the World Wide Web are fetched from a server that's usually running Apache with a bunch of add-ons for stuff like executing PHP. The environment that your Chrome extension code runs in isn't any of that, so PHP won't run; it'll just get treated like any other text in the file. The only things that make your extension different from a plain HTML file loaded from the file:// protocol are the manifest.json file and some special privileges.
Now on to your question. It's not very clear, but it sounds like you were trying to use PHP to get around the fact that browsers won't let you directly fetch a file on another domain with Ajax. But Chrome will in fact allow a Chrome extension to do this, if it requests this permission. Head to the Cross-Origin XMLHTTPRequest page and scroll down to "Requesting cross-origin permissions" for more information.

Related

AJAX URLs & URL Rewriting

I am starting to set up a personal website, and I would like it's layout to look something like
-------------------------------
- Page Header & Menus Go Here -
-------------------------------
- Main Contents -
-------------------------------
- Footers -
-------------------------------
The main question is that I would like it to be a single-page interface in which the main contents are loaded and displayed with a combination of AJAX and jQuery to produce a nice effect. However, I would, of course, like to have the contents bookmark-enabled and indexed by search engines. I have skimmed throught the Single Page Interface Manifesto which explains some nice ways of achieving this, but I wouldn't really like to have my URLs like
http://www.mysite.com/index.php#!section=section1
http://www.mysite.com/index.php#!section=section2
I would, of course, like to re-write them as
http://www.mysite.com/section1
http://www.mysite.com/section2
My questions are this whether this approach is correct/doable and if AJAX URLs are compatible with URL rewriting. What URLS would be indexed by, say, Google anyway?
If you want your page to work without reloading and update at the same time the page's URL, the only way to archieve this is by changing the hash in the URL (location.hash = 'whatever').
URL rewriting cannot be used since the hash is not sent to the server, it's only available in the browser's scope.
Check Facebook or Twitter URLs. They are prettier than #!section=section1 but still need the hash.
Cheers.
If you want to load different content/tabs/some content of page without reloading browser,
Now It is possible with pjax..
you can use something like http://padrino-pjax.heroku.com/
you can try it, go to the link and click on any of links home,dinosaurs,aliens
and you will see It will change url and some content without reloading full page
It is achieved using ajax+push/pop of url in browser
I'm looking for a solution myself for a similar problem (I have a client site with an AJAXed wordpress theme, and these dreadful #! stuff on the URL prevent all the Social sharing plugins I have tried so far, from working correctly).
Apparently, there is a solution (with some drawbacks ofc..). I found about it here: http://moz.com/blog/create-crawlable-link-friendly-ajax-websites-using-pushstate
I know it's like two years since you've asked, but it could be helpful for someone else, or you may wanna check it out just for the sake of the curiosity itself! :-)

Google Search optimisation for ajax calls

I have a page on my site which has a list of things which gets updated frequently. This list is created by calling the server via jsonp, getting json back and transforming it into html. Fast and slick.
Unfortunately, Google isn't able to index it. After reading up on how to get this done according to Google's AJAX crawling guide, I am bit confused and need some clarification and confirmation:
The ajax pages need to be implement the rules only, right?
I currently have a rest url like
[site]/base/junkets/browse.aspx?page=1&rows=18&sidx=ScoreAll&sord=desc&callback=jsonp1295964163067
this would need to become something like:
[site]/base/junkets/browse.aspx#page=1&rows=18&sidx=ScoreAll&sord=desc&callback=jsonp1295964163067
And when google calls it like this
[site]/base/junkets/browse.aspx#!page=1&rows=18&sidx=ScoreAll&sord=desc&callback=jsonp1295964163067
I would have to deliver the html snapshot.
Why replace the ? with # ?
Creating html snapshots seems very cumbersome. Would it suffice to just serve simple links? In my case I would be happy if google would only index the things pages.
It looks like you've misunderstood the AJAX crawling guide. The #! notation is to be used on links to the page your AJAX application lives within, not on the URL of the service your appliction makes calls to. For example, if I access your app by going to example.com/app/, then you'd make page crawlable by instead linking to example.com/app/#!page=1.
Now when Googlebot sees that URL in a link, instead of going to example.com/app/#!page=1 – which means issuing a request for example.com/app/ (recall that the hash is never sent to the server) – it will request example.com/app/?_escaped_fragment_=page=1. If _escaped_fragment_ is present in a request, you know to return the static HTML version of your content.
Why is all of this necessary? Googlebot does not execute script (nor does it know how to index your JSON objects), so it has no way of knowing what ends up in front of your users after your scripts run and content is loaded. So, your server has to do the heavy lifting of producing a HTML version of what your users ultimately see in the AJAXy version.
So what are your next steps?
First, either change the links pointing to your application to include #!page=1 (or whatever), or add <meta name="fragment" content="!"> to your app's HTML. (See item 3 of the AJAX crawling guide.)
When the user changes pages (if this is applicable), you should also update the hash to reflect the current page. You could simply set location.hash='#!page=n';, but I'd recommend using the excellent jQuery BBQ plugin to help you manage the page's hash. (This way, you can listen to changes to the hash if the user manually changes it in the address bar.) Caveat: the currently released version of BBQ (1.2.1) does not support AJAX crawlable URLs, but the most recent version in the Git master (1.3pre) does, so you'll need to grab it here. Then, just set the AJAX crawlable option:
$.param.fragment.ajaxCrawlable(true);
Second, you'll have to add some server-side logic to example.com/app/ to detect the presence of _escaped_fragment_ in the query string, and return a static HTML version of the page if it's there. This is where Google's guidance on creating HTML snapshots might be helpful. It sounds like you might want to pursue option 3. You could also modify your service to output HTML in addition to JSON.
I've more or less given up on this. There really seems no alternative to generating the html on the server and delivering it in the html bdoy if you want goolge to index your directory.
I even tried adding a section wraped a .net user control which implemented a simple html version of the directory. But google also managed to ignore ..
So in the end my directory has been de-ajaxified. :(

With Google's #! mess, what effect would a redirect on the converted URL have?

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.

Cross site scripting(XSS)

I am loading content from another page and depending on the content of page, changing content of my page and this is giving me cross site scripting issues.
When i use iframe, since the content is from other domain, content of iframe becomes inaccessible.
When i use ajax and try to inject the content as plain html code, XmlHttpRequest object throws permission denied exception due to cross site scripting.
When i use JSONP, such as getJSON in JQuery, it only supports GET protocol and it is not adequate for further processing.
I wonder what other options i can try. Heard that DOJO, GWT,Adobe Air do some XSS, but dont know which one is the best.
Thanks,
Ebe.
Without JSON-P, your only option is to run a proxy script on your own server that fetches the content from the external site and pipes it back to the browser.
The browser fetches the content from the script on your server, hence no cross-domain issues, but the script on your server dynamically fetches it from the external site.
There's an example of such a script in PHP here: http://www.daniweb.com/code/snippet494.html (NB. I haven't personally used it).
If you have control over both domains, take a look at EasyXDM. It's a library which wraps cross-browser quirks and provides an easy-to-use API for communicating in client script between different domains using the best available mechanism for that browser (e.g. postMessage if available, other mechanisms if not).
Caveat: you need to have control over both domains in order to make it work (where "control" means you can place static files on both of them). But you don't need any server-side code changes.
To add to what RichieHindle says, there are some good script (Python+Cron) that you can plonk on your server and it will check for changes to a POST/GET location and cache the changes on your server.
Either set your triggers low (once every 10 mins/ 1 per day) or you might get blacklisted from the target.
This way, a local cache won't incur the HTTP overhead on every AJAX call from the client.

Javascript: achieving the Google Ad AJAX effect

I need to create a portable script to give to others to implement on their websites that will dynamically show content from my database (MySQL).
I know AJAX has a cross-site problem, but it seems that Google's ad's somehow manage the effect in a cross-browser / cross-site fashion.
Knowing that I have to give people a simple cut/paste snippet to put in their website...how can I achieve this? How did Google?
They use an <iframe>, so the ad is served from their server, and can talk to their database. I'm not actually sure that they use any sort of AJAX from their ads, though; they appear to just be mostly static content, with a few scripts for tweaking the formatting (which are optional, since they want their ads to be visible even if users have JS turned off).
Remember, you can always look into this on your own, and see what they did. On Firefox, use Firebug to explore the html, css, and scripts on a site. On WebKit based browsers (Safari, Chrome, and others), you can use the Web Inspector.
Google's ad code is loaded via a script tag that calls a remote javascript file. The AJAX restrictions that are generally enforced with xmlhttp, iframe, and similar AJAX requests don't apply when it comes to loading remote javascript files.
Once you've loaded the javascript file, you can create iframes in your page that link back to the actual hosted content on your server (and feed them any data about the current page that you wish).
jQuery has built in support for jsonp in their ajax calls. You may want to lookin in to using that if you are really needing to use ajax.
http://api.jquery.com/
http://docs.jquery.com/Ajax
You don't need iFrames and you don't need AJAX. It's really, really simple!
You pull in a remote JS file that is actually a constructed file from php/asp/whatever. In your JS file you have a document.write script that writes the content. It's that simple.
We do this all the time with media stored on separate sites. Here's an example.
YOUR SERVER: file.php (which outputs js)
<script>
document.write("I'm on a remote server");
</script>
OTHER SITE:
<script src='http://www.yourserver.com/file.php'></script>
And it will output the content generated by the script. To make the content customized you can put in script vars above the script call that will adjust what your file pulls out. From there it's pretty straightforward.
I realize this question is a year old, but I've written a library that can help with the document.write part of the problem (whether this is a TOS violation, I don't know) writeCapture.js. It's pretty simple:
$('#ads').writeCapture().html('<script src="whatever-your-adsense-code-is"> </script>');
The example uses jQuery, but you can use it standalone as well.

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