I wrote a Google Chrome extension, which popups a dialog with an autocomplete field and it's own style, but there are some sites where my CSS gets totally broken, which doesn't look very nice.
I know about isolating styles with iFrames, but in Google Chrome extension there is no way to isolate my HTML and CSS in this way. Another method is to wrap all my stuff into a separated div with it's own id and relative styles for that id, and I do so, but it seems that it doesn't work on some sites with "hard" tags style overloading or "!important" directives in the CSS code.
So, I want to know is there any way to really isolate my styles in z convenient way or it's my bad carma to overload every little CSS property to fix one or another style issue for each site?
By the way: I set up my manifest to load all the things at the "document_end", but I see it's not being applied to the stylesheets which is every time loaded whenever the DOM is ready.
At the time of asking the question, your only option was to either use iframes, or stylesheets with a very high specificity and explicitly set all properties that might affect styles. The last method is very cumbersome, because there will always be some property that is overlooked by you. Consequently, the only usable method for isolating stylesheets was to use iframes.
The solution to this problem -isolation of styles without iframes- is Shadow DOM (since Chrome 25). You can find a tutorial at HTML5 Rocks. For a real-world Chrome extension that uses Shadow DOM to isolate styles, see Display #Anchors (source code here).
As I've recently gone through the gauntlet of this issue, I want to share some information I think is valuable.
First, Rob W's answer is correct. Shadow DOM is the correct solution to this problem. However, in my case not only did I need CSS isolation, I also needed JavaScript events. For example, what happens if the user clicks a button that lives within the isolated HTML? This gets really ugly with just Shadow DOM, but we have another Web Components technology, Custom Elements, to the rescue. Except that as of this writing there is a bug in chrome that prevents custom element in chrome extensions. See my questions here and here and the bug here.
So where does that leave us? I believe the best solution today is IFrames, which is what I went with. The article shahalpk linked is great but it only describes part of the process. Here's how I did it:
First, create an html file and js file for your isolated widget. Everything inside these files will run in an isolated environment in an iframe. Be sure to source your js file from the html file.
//iframe.js
var button = document.querySelector('.my-button');
button.addEventListener('click', function() {
// do useful things
});
//iframe.html
<style>
/* css */
</style>
<button class='my-button'>Hi there</button>
<script src='iframe.js'></script>
Next, inside your content script create an iframe element in javascript. You need to do it in javascript because you have to use chrome.extension.getURL in order to grab your iframe html file:
var iframe = document.createElement('iframe');
iframe.src = chrome.extension.getURL("iframe.html");
document.body.appendChild(iframe);
And that's it.
One thing to keep in mind: If you need to communicated between the iframe and the rest of the content script, you need to chrome.runtime.sendMessage() to the background page, and then chrome.tabs.sendMessage from the background page back to the tab. They can't communicate directly.
EDIT: I wrote a blog post detailing everything I learned through my process, including a complete example chrome extension and lots of links to different information:
https://apitman.com/3/#chrome-extension-content-script-stylesheet-isolation
In case my blog goes down, here's the sources to the original post:
Blog post
Example source
Either use all
.some-selector {
all: initial;
}
.some-selector * {
all: unset;
}
or use Shadow DOM
Library
function Widget(nodeName, appendTo){
this.outer = document.createElement(nodeName || 'DIV');
this.outer.className = 'extension-widget-' + chrome.runtime.id;
this.inner = this.outer.createShadowRoot();
(appendTo || document.body).appendChild(this.outer);
}
Widget.prototype.show = function(){
this.outer.style.display = 'block';
return this;
};
Widget.prototype.hide = function(){
this.outer.style.display = 'none';
return this;
};
Usage
var myWidget = new Widget();
myWidget.inner.innerHTML = '<h1>myWidget</h1>';
You can access the widget contents via myWidget.inner and the outer via myWidget.outer.
Styles
/*
* Reset Widget Wrapper Element
*/
.extension-widget-__MSG_##extension_id__ {
background: none;
border: none;
bottom: auto;
box-shadow: none;
color: black;
cursor: auto;
display: inline;
float: none;
font-family : "Helvetica Neue", "Helvetica", "Arial", sans-serif;
font-size: inherit;
font-style: normal;
font-variant: normal;
font-weight: normal;
height: auto;
left: auto;
letter-spacing: 0;
line-height: 100%;
margin: 0;
max-height: none;
max-width: none;
min-height: 0;
min-width: 0;
opacity: 1;
padding: 0;
position: static;
right: auto;
text-align: left;
text-decoration: none;
text-indent: 0;
text-shadow: none;
text-transform: none;
top: auto;
vertical-align: baseline;
white-space: normal;
width: auto;
z-index: 2147483648;
}
/*
* Add your own styles here
* but always prefix them with:
*
* .extension-widget-__MSG_##extension_id__
*
*/
.extension-widget-__MSG_##extension_id__{
position: fixed;
top: 100px;
margin: 0 auto;
left: 0;
right: 0;
width: 500px;
}
.extension-widget-__MSG_##extension_id__::shadow h1 {
display: block;
margin: 0 auto;
padding: 20px;
background-color: yellow;
border: 10px solid green;
font-size: 20px;
text-align: center;
}
I recently created Boundary, a CSS+JS library to solve problems just like this. Boundary creates elements that are completely separate from the existing webpage's CSS.
Take creating a dialog for example. After installing Boundary, you can do this in your content script
var dialog = Boundary.createBox("yourDialogID", "yourDialogClassName");
Boundary.loadBoxCSS("#yourDialogID", "style-for-elems-in-dialog.css");
Boundary.appendToBox(
"#yourDialogID",
"<button id='submit_button'>submit</button>"
);
Boundary.find("#submit_button").click(function() {
// some js after button is clicked.
});
Elements within #yourDialogID will not be affected by the existing webpage. And find() function returns a regular jQuery DOM element so you can do whatever you want with it.
Hope this helps. Please let me know if you have any question.
https://github.com/liviavinci/Boundary
Use iframes. It's a workaround, but works fine.
Maxime has written an article on it.
I don't have dyslexia, yet still feeling much hard to read any text on the screen. So I want to add letter-spacing & word-spacing on my Kinder app by changing its local files. The problem is, after I changed contents of the local files, Kinder won't be launched. It simply doesn't response.
Here's what I have done on app-index.js file;
// app-index.js
<style>
* {
letter-spacing: 1em;
word-spacing: 1em; // values are just for testing.
}
</style>
In bundle.js file(optimised);
g(e,"table.amazon-table-style-0 tr th","border:none; padding:1px; text-align:justify; letter-spacing:1em; word-spacing:1em")
I would like to have some solutions to resolve my problem. (I'm working on Mac)
Thanks.
======= Progress Updated =======
I found styles.css file later in /Applications/Kindle.app/Contents/Resources and I modified it. However, the app still won't open.
// styles.css
* {
letter-spacing: 15px;
}
I am using Emotion 11 as css-in-js lib for a React project.
My goal is to generate styles with a given prefix to the selector in order to increase specifity (the pages also include legacy css).
.c50id {
color: pink;
}
to
#my-chosen-id .c50id {
color: pink;
}
I found questions suggesting to use stylis-plugin-extra-scope but it does not seem to work anymore due to the upgrade to stylis 4.
Any suggestion is welcomed,
thank you!
So, I'm building a hybrid app using the Ionic framework and AngularJS.
I created a volume slider with a custom style, using the code below:
style.css
input[type=range] {
-webkit-appearance: none;
height: 9px;
background-image: url("/img/bar.png");
border: none;
width: 280px;
}
input[type=range]::-webkit-slider-thumb {
-webkit-appearance: none;
border: none;
height: 30px;
width: 30px;
background-image: url("/img/slider.png");
}
When I test it in the browser it works fine. But the problem is: to run it in Android I have to add "android_asset/www/" in the image path. For all the images that I'm using in the html, I made a function in the js file that detects if the app is running in Android, and if it returns true, the function automatically add the "android_asset/www/". But in my case, the images for the volume slider's style are added in the CSS, so I can't call the js function.
So, how can I fix it? How to add "android_asset/www/" to the image's path in the CSS only if it is running in Android? Is there a way to call the js function in CSS? Is it possible to change the image's path in CSS from the html?
This is the js function's code:
app.js
$scope.convertAndroid = function(src){
if(device.platform.toLowerCase() === "android") { src = "/android_asset/www" + src; }
return src;
};
And this is how I invoke the function in the html
index.html
<img src={{convertAndroid('/img/something.png')}}>
Well, there is a mistake in the general concept here. A hybrid application creates separate WWW folders for each platform, i.e. web, Android, IOS, etc. For example, following is the general hierarchy:
root project
----wwww
--------platforms
------------android
----------------assets
--------------------www
------------ios
It means that, every platform sees the related WWW folder as the root directory. If you are running on Android, it will read the WWW inside assets. You just have to create the same content for every WWW folder in your project.
Ext.util.CSS.createStyleSheet(
'.cleanForm .x-form-text.x-superboxselect { background: none; border-color: white; } ' +
'.cleanForm .mySuperSelectItem a { background: url(../sprite.png) no-repeat 0px -50px; } ' +
Ext.id( null, 'someStyleSheet')
);
This stylesheet works in FireFox. The second rule works in IE. The first rule does not work in IE. It appears when IE loads the stylesheet, it ignores the third class creating a rule not applicable for my code.
Has anybody seen problems with multiple class selectors that follow a third, parent class?
What version of IE are you using? I tested IE9 on this mulitclass selector test page and it doesn't look like it properly supports multiclass selectors in quirks mode. Have you set a doctype? Switching to standards mode in IE7+ looks better.
Some cursory googling found this blog post with a good discussion in the comments.