I've a chrome extension which modifies the pages Dom. But the page is in angular so I need to change the scope of the element. How can I do that?
What you want is to interact with the page's JS context from the content script. There is nothing special about AngularJS in this regard.
In order to be able to interact with the page's JS you need to inject some code into the page.
This can be achieved in a lethora of ways and this answer covers them all in great detail.
Related
I have a content script running inside the Gmail UI and I am injecting some new HTML at different points. This is all working, but to keep the code clean I wanted to insert pre-defined HTML markup into certain parts of the page in a single function call.
This all seems feasible using chrome.extension.getURL(), but when I was testing this, it looks like chrome.extension is undefined! I was unable to find anywhere in the documentation that says this shouldn't be defined and several places where it says it should.
I am using chrome Version 39.0.2171.95 (64-bit)
Here is what the chrome object looks like in the javascript console:
First off, anyone know why chrome.extension might be undefined? Secondly, is there another (perhaps better) way to do this? I'd rather not just programmatically inject a large amount HTML into the page in code using jQuery, etc. in the content script, but can resort to this if there is no other way.
If you're testing this in the console, you must be aware of the concept of the Isolated World. When you add a content script, it has a separate JavaScript context for itself that is isolated from the page.
At the top of the Console tab of Dev Tools, you'll see <top frame> in a dropdown. This is a dropdown that selects JS context it is executing in. It will list frames inside the document and all extensions that have content scripts injected.
The chrome object you show in the screenshot corresponds to what the webpage normally sees. If you switch context, you'll see a different picture:
In any case, if you are really executing chrome.extension.getURL() in the content script - it will be well defined.
Now, if you injected a <script> tag in the page and tried it in that code - it would fail again, since the code will be in the page context. See this question for this situation.
Finally, most of the Chrome API will not be exposed to content scripts for security reasons. If an API is undefined when it shouldn't be, you may need a background page to do the job for you.
I'm trying to create a web page able to change a site visualization (.css or / and .js) in order to recreate the same live change capability offred by Firebug for Firefox or the Inspector of Chrome.
Here an image to better explain my task:
I have been able to visualize the other site inside my page using the iframe, but unfortunately it is not possible to change its visualization and access its elements due to the "same origin policy".
Is there a way to do this using the iframe or loading the external site inside another element?
Update:
Considering the answers the options should be:
create a php proxy page to load the target site and change visualization on it.
create a browser extention.
I've tried the first, even if it requires to install a web server (xampp), with a simple page calling the function file_get_contents('http://www.site.com');
The page is loaded but unfortunately missed some elements (like images) and it is only a static copy; it is not possible to go further in the site navigation.
Update 2:
Load the entire page via javascript could be the better solution (I don't konw how) if it is possible to live change the code but what about the possibility to interact with this "page copy" and transfer the interaction to the original one?
Scheme:
Explanation:
I've noticed Firebug extention can select and live edit any page element, even if they belong to the iframe which loads an external domain page.
What I'm looking for is a way to act like Firebug, get an element and change its style.
I'm trying to load the site into the iframe beacuse I wanted to create a toolbar above it to select my "visualization styles"; for example a button to makes titles bigger and red.
Anyway I'm open to any other methods suggestions.
Update 3:
I have found an extention for both FireFox and Chrome which is really close to my aim: "Stylish"
This add on allows to live change any site css proprerty and save it in order to reload them every time you'll visit the page.
Now my question is: How can I do the same creating a dedicated page to load and change visualization of a specific site?
FINAL EDIT:
In order to continue this question with a more relevant arguments I decided to ask a new one: create a php proxy page
No. Your solutions may be
to let your own site act as proxy so the same origin policy isn't triggered
to build an extension, which will be browser dependent (Firefox or Chrome) and which will require authorization and installation
I'm not sure if I understand what you want very well, but my feeling to ''trick'' this easier would probably to give very specific height and width to your first site (the iframe) and do a jQuery condition
If ($('body').width() == 500 && $('body').height() == 400 {
$('body').addClass('isiFrame');
}
Then, you only have to do your css .isiFrame .myCoolDivs {....}
You might have to use it on a document ready also, but that could be one way to trick it and since you're not doing it on resize (exepect if somebody's having his screen at this exact width and height at start)
The safer way would probably to create a master session using PHP but I cannot give you an example since it've been to long and echo the body class if the master_session or variable is equal to true
Hope it helped!
If you try to fight Same_origin_policy and try to fight it I am sure you won't get much success their.
Server Side
I would suggest you Handle this on server-side, grab the web-page and apply whatever styling and scripts you want, should be very easy!!
If you use Ruby on rails - Nokogiri gem can help you to parse html. And you can use standard library to 'get' a webpage.
Client Side
If you want to do this on client side, you need to write some jquery/javascript code, you can take following steps:
Get the webpage you want to display.
Grab the element's which include js/css files, remove them and your own.
Display the page in new Iframe present in your page.
I've been looking into using an iframe to sandbox some javascript for a site module. I have one core question before I start to code and test this. Could adding and then removing an iframe from a webpage prompt Google to ban a website?
I'm not even sure if this is possible but here's what I'm hoping to do in a nutshell:
All of this is necessary to ensure comparability of my module with any website. I'll load a hidden iframe on the page. The frame will handle jquery operations & ajax calls for my module. Once the iframe has loaded I hope to store a reference in the parent window to a function in the iframe. I would then like to use javascript to remove the iframe from the page, while maintaining and utilizing the function reference. I'd appreciate insight into the feasibility of this, in addition to my core question.
Thanks,
skibulk
No, google won't take action against you for dynamically creating an iframe. It's done all the time. I'm not sure whether "iframe sandboxing" works on safari though.
I have developed a small component which can be put in to any website. Now, I want to develop a code that could demonstrate how would my component look like on any website.
So, the person would come to my page and put in his URL and then my code should embed my custom JS/CSS in to the downloaded HTML and display it. Something like this.
Here, like the feedback tab, I want to show my component any where on that page.
Try a bookmarklet.
Create a piece of javascript that adds your code into the page such as the following:
javascript:(function(){var%20script=document.createElement('script');script.src='http://www.example.org/js/example.js';document.getElementsByTagName('head')[0].appendChild(script);})()
Add it as the href of a link like so:
Link Text Here
Tell your users to drag the link to their bookmark toolbar and click on it on different websites to try your code out.
Some examples: http://www.reclaimprivacy.org/, http://www.readability.com/bookmarklets
In the example you linked, they are requesting the page specified in the url querystring parameter on the server, and then doing more or less the following steps:
In the <head> tag they are adding a <base href="url" /> tag to the document. The base tag will make any relative links in the document treat the value in the href attribute as their root. This is how they are getting around broken css / images. (The base tag is supported by all browsers)
At the end of the document (IE the </body> tag) they are injecting the javascript that runs their demos.
They serve the modified HTML requested to the browser.
All of this is pretty straight forward in implementation. You could use regular expressions to match the <head> and </body> tags for steps 1 and 2 respectively. Depending on the server platform how you actually request the page will vary, but here are some links to get you started:
C# - HttpWebRequest object documentation
PHP - HttpRequest::send
Nathan's answer is the closest to how we have done the demo feature at WebEngage. To make such a demo functional, you'll need to create a Javascript widget that can be embedded on third party sites. syserr0r's answer on creating a bookmarklet is the simplest approach to do so. Our's is a JAVA backend and we use HttpClient to fetch the responses. As Nathan suggested, we parse the response, sanitize it and add our widget Javascript to the response. The widget JS code takes it on from there to render the Feedback tab and load a demo short survey.
Disclosure: I am a co-founder and ceo at WebEngage.
You can not do this with JQuery due to cross site scripting restrictions.
I suggest you write a PHP script that downloads the URL specified by the user and includes your widget code and then echo it back to the user.
I recommend using bookmarklets. I've made a bookmarklet generator for adding jQuery-enabled bookmarklets to a page to make development easier.
There's a caliper bookmarklet on the page that you can mess around with just to show an example of it working.
Full disclosure, this is something I've made, I'm not trying to be spammy as I think it's relevant: zbooks
You could make an iframe page, which loads their page in the iframe, and uses javascript to inject your code into the iframe.
Here is my approach...
http://jsfiddle.net/L2kEf/
html
<iframe src="http://www.bing.com"></iframe>
<div>I am div</div>
css
div { background: red; position: absolute; top: 20px; width: 100px; left:20px;}
iframe{width: 100%; height: 500px;}
you can add javascript/jquery too, so you could do something like,
jQuery //not 100% sure it would work coz of cross browser thingy, but you know, worth a try.
$('div').click(function (){
$('iframe').contents().html('changed');///
});
if this can't change any of the contents, you can display a dialog, to say it would normally work if it was in your website, then use #syserr0r approach for bookmarked users, for better results, since you are offering this kinda services, to developers, im sure they would know about bookmarking, my approach would be rarely used :) so hope it helps.
I had a problem of a similiar nature, and the main obstacle is the cross-domain policy.
You have to ask the user to put your code in a <script src="..."> or create a proxy solution that would add your code for them.
I went for the proxy and here are my observations:
it's easy to create a basic proxy in php - there are some php proxies on sourceforge and Ben Alman has created a simple php proxy for AJAX. Based on those I was able to create a php proxy altering the content properly in one day.
after that I spent a lot of time making it work with more and more sites with issues. You can never create a perfect proxy.
As an alternative (sa long as you are non-commercial) you can use http://www.jmarshall.com/tools/cgiproxy/ and put the site in an iframe and then do whatever you want to do with the iframes document, as it's in your domain thanks to the proxy. You can access iframeDOMnode.contentWindow.document then, etc.
You can create a Crossrider extension which your users can download.
Then simply add this to your App/Extension code:
appAPI.dom.addRemoteJS("http://yourdomain.com/file.js")
Your users can then download the extension (it works cross-browser for Internet Explorer, Chrome and Firefox) and it will load your JS code on every page load.
You can get an approximation of what it will look like using a iframe. Take a look at that link for an example.
http://jsfiddle.net/jzaun/5PjRy/
The issue with this appoch is that you can't move your DIV(s) when the page scrolls, they are in effect just floating over the iframe. There is no way around this as cross-domain scripting wont let you access the iframe's document to monitor scroll events.
The only other option you have for a better fitting example would be to load the page from the server side in whatever scripting language you are using and load that into the iframe (or into a div, etc.) and you can use javascript all you want as the page is coming from your domain.
For your example of what will your widget look like I imagine floating your DIV(s) over an iframe would give enough of an idea.
Please note the example you gave is using the server side method, not the iframe method.
I agree with the bookmarklet strategy.
I'm a fan of http://bookmarklets.heroku.com/, which lets you generate bookmarklets easily, inject jQuery, etc.
Hiho,
There's an existing website that i need to include into another site which goes like this:
a.mysite.com
and i need to fetch content from this site in my
www.mysite.com
website...
As i need to access the content of the iframe the Same origin policy produces a problem here.
What i did was to configure mod_proxy on Apache to proxy pass all requests from
www.mysite.com/a
to
a.mysite.com
This will work fine...but my problem is that im not sure what the best way would be to include those pages.
1. Idea
As the content of the iframe is a full featured site with a top navigation...left navigation etc....i would need to change the page template to only show the content box to be able to integrate that page in the iframe.
2. Idea
I could just load the DIV where the content lies through JQuery.load() and integrate it into my site.
What is the best way to accomplish such a task? How bad is both ideas from the SEO point of view?
Unless it involves significant rework, the best solution is to combine the two into a single HTML page on the server side (using server-side includes).
Advantages:
No problems with SEO as it's delivered as a single page. Content in iFrames and content loaded via AJAX (with an associated link in the HTML) are traversed, but only the link, not the content itself is associated with the main page. See: http://www.straightupsearch.com/search-marketing/best-practices/seo_iframes_a_g/
Faster page load - either of your suggestions will cause the main page to be loaded first before the other content is loaded.
No reliance on Javascript - your second method will fail completely if javascript is not supported / turned on.
Include all JS and CSS only once - your first method will require these to be duplicated in the <head> of each page. This is more of a long term advantage if you wish to achieve full integration of site "a". However, it can be a disadvantage initially, see below.
Disadvantage:
May cause conflicts with scripts and CSS between the two pages. However, this same problem exists with your second method.
If you must choose between either of the two options you proposed, I would not select the second as others have suggested. Significant amounts of static content should never be loaded via Ajax, and in this scenario gives you no additional benefits. At least iFrames guarantee no JS and CSS conflicts.
Use the 2nd approach (jQuery.load) and if you're working with HTML5, for browsers that support the History API you can change the URL to whatever the content is for that div.
Check out https://github.com/blog/760-the-tree-slider for an example of how github did it for their tree slider.
EDIT:
I am not sure how using an iFrame whose src points to your own domain affects search rankings but at best it's a grey area. I would assume that possibly some pagerank would trickle from the parent to the child but I have no clue how it would work for instance if a blogger linked to your page with the iframe that pointed to another page. This would be a pretty good question to ask at the Webmaster Help Forum
Always say no to iframes. jQuery+Ajax all the way.