I use loadURL to load the web, I want to make some changes. Is there a way to inject a css snippet once the page is rendered?
There are extensions for chrome that do what I want (like UserCSS), but I understand that they can't be used inside an Electron App.
After your page has completed loading...
Here is an example of adding CSS:
// When document has loaded, initialize
document.onreadystatechange = (event) => {
if (document.readyState == "complete") {
// Document has finished loading here
var styles = `img#license {
animation: none;
animation-iteration-count: 1;
animation-fill-mode: forwards;
position: absolute;
z-index: 3;
width: 375px;
top: 204px;
left: 112px;
visibility: hidden;
}`
var styleSheet = document.createElement("style");
styleSheet.innerText = styles;
document.head.appendChild(styleSheet);
}
};
I use the above to display a unlicensed image over my Electron app from the preload.js script, as it has access to the document element.
Edit the CSS to your needs.
Related
I decided to dip my toes in Vue and have had an idea for a website for a while which I'd like to use amCharts5 for.
I had some issues initially as all the info I could find was related to Vue2, but I think I've somewhat wrapped my head around Vue3 and its composition API.
The MapChart is created, however there is always a div slapped on top of it which prevent any interaction. If I delete this element via DevTools, the MapChart becomes interactive.
I've tried debugging this and commenting sections of the code out, regardless this div is always created. And I simply can't figure out if it's injected by Vue or if amCharts 5 is the culprit.
The highlighted element is the one I must delete for it to become interactive.
Here's how the component is setup;
<template>
<div class="testClass" ref="chartdiv">
</div>
</template>
<script setup lang="ts">
import * as am5 from "#amcharts/amcharts5";
import * as am5map from "#amcharts/amcharts5/map";
import am5geodata_worldLow from "#amcharts/amcharts5-geodata/worldLow";
import am5themes_Animated from '#amcharts/amcharts5/themes/Animated';
import { ref, onMounted, onUnmounted } from "vue";
const chartdiv = ref<HTMLElement | null>()
var root!: am5.Root;
onMounted(() => {
if (chartdiv.value) {
// Create the Root
var root = am5.Root.new(chartdiv.value);
// Setup the MapChart
var chart = root.container.children.push(
am5map.MapChart.new(root, {
panX: "rotateX",
panY: "rotateY",
projection: am5map.geoOrthographic(),
centerMapOnZoomOut: false
})
);
// Setup Animations
root.setThemes([
am5themes_Animated.new(root)
]);
// Create MapPolygons
var polygonSeries = chart.series.push(
am5map.MapPolygonSeries.new(root, {
geoJSON: am5geodata_worldLow
})
);
// Setup MapPolygon Styling
polygonSeries.mapPolygons.template.setAll({
tooltipText: "{name}",
fill: am5.color("#909090")
});
// Setup MapPolygon Hover Styling
polygonSeries.mapPolygons.template.states.create("hover", {
fill: am5.color("#FF0000"),
stroke: am5.color("#00FF00"),
strokeWidth: 2
});
polygonSeries.mapPolygons.template.events.on("click", function(event) {
//console.log("Clicked: {0}", event.target);
});
// Setup Background
var backgroundSeries = chart.series.unshift(
am5map.MapPolygonSeries.new(root, {})
);
backgroundSeries.mapPolygons.template.setAll({
fill: am5.color(0x2c84d0),
stroke: am5.color(0x2c84d0)
});
backgroundSeries.data.push({
geometry: am5map.getGeoRectangle(90, 180, -90, -180)
});
}
});
onUnmounted(() => {
if (root) {
root.dispose();
}
});
</script>
<style scoped>
.testClass {
width: 50vw;
height: 50vh;
}
</style>
When you create a Vite-powered Vue project, it automatically creates a bunch of CSS files for you. One of those is base.css.
Inside this file, you'll find these lines which causes all the headache;
*,
*::before,
*::after {
box-sizing: border-box;
margin: 0;
position: relative;
font-weight: normal;
}
Removing those lines will fix the issue.
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 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.
Im testing using react-testing-library and jest-styled-components.
I have a wrapper component that renders the styles of its child button dependant on a selected prop passed to it.
This is the code:
const selectedStyles = css`
background-image: url(../image);
background-position: center;
background-repeat: no-repeat;
border-color: ${color.grey6};
height: 38px;
width: 58px;
& span {
display: none;
}
`;
const ButtonWrapper = styled.div`
& button {
font-size: 15px;
line-height: 20px;
padding: 8px 12px;
${props =>
props.selected
? css`
${selectedStyles}
`
: ""}
&:hover,
:focus {
${props =>
props.selected
? css`
${selectedStyles}
`
: ""}
}
}
`;
and the test
test("it renders the correct styles when selected ", () => {
const { container } = render(<CheckButton selected>Add</CheckButton>);
const button = container.querySelector("button");
expect(button).toHaveStyleRule("background-position", "center");
});
but its failing with "Property 'background-position' not found in style rules" which is true for the original button, however when its parent is passed the selected prop this style applies.
I am also doing snapshot testing with the component however not testing the props getting passed brings the test coverage down.
Can anyone help?
In general as far as nested styles testing is concerned, I would recommend testing directly the nested element.
I personally haven't figured out a way to test nested styles using the .toHaveStyle(``); (not even a simple
a {
text-decoration: none;
}
)
so I ended up querying for the exact component I wanted to test, eg:
expect(screen.getByText(/text-within-the-child-component/i)).toHaveStyle(`
text-decoration: none;
`);
In your specific case I believe the way to go is to render your component in your test directly with the props that trigger the styles you want for each case (selected in your code example).
For those who are facing the same problem toHaveStyleRule accept a third "options" parameter after property and value where you can path a modifier:
test("it renders the correct styles when selected ", () => {
render(<CheckButton selected>Add</CheckButton>);
const button = container.querySelector("button");
expect(screen.getByText("Add").parentElement).toHaveStyleRule("background-position", "center", { modifier: 'button' });
});
Here I state on the fact that "Add" is the button text and its parent is the component ButtonWrapper.
By the way, you should avoid as much as possible using querySelector (here I'm using react testing library).
https://github.com/styled-components/jest-styled-components
Working on a little self project and having some trouble getting text placed on top of my background video.
At present, the code is sitting as follows:
<div class="video_container">
<div class="contentContainer">
<div class="skipButton">
<h1>Skip</h1>
</div>
<video id="tgVideo" autoplay loop>
<source src="videos/bgvidm4v.m4v" preload="none">
</video>
</div>
</div>
I am making the video full screen and keep this way when displaying on different size monitors by using the following JS
$(document).ready(function () {
var vid = $('video');
var vid_w_orig = 1280;
var vid_h_orig = 720;
// re-scale image when window resizes
$(window).resize(function () {
//Get the parent element size
var container_w = vid.parent().width();
var container_h = vid.parent().height();
//Use largest scale factor of horizontal/vertical
var scale_w = container_w / vid_w_orig;
var scale_h = container_h / vid_h_orig;
var scale = scale_w > scale_h ? scale_w : scale_h;
//Scale the video to fit any size screen
vid.width(scale * vid_w_orig);
vid.height(scale * vid_h_orig);
});
//Trigger re-scale of the video on pageload
$(window).trigger('resize');
});
This combination is working flawlessly for me so far. Only issue is getting the video to run on Android/iOS, but I think that's a limitation of the device.
What I am in need of is adding a piece of text for now that a user can click on to bring them away from the video. I am adding the href to the button after I get the text to display on top of the video.
I have found some tutorials online and have tried the below
.video_container .contentContainer {
position: absolute;
width: 100%;
height:100%;
background:#000;
opacity:0.5;
z-index:999;
}
.video_container .contentContainer .skipButton {
width:100%;
text-align:center;
}
.video_container .contentContainer .skipButton h1 {
color:#FFF;
text-transform:uppercase;
}
This is working for the most part, where I can see the text for a split second before it disappears behind the video.
Anyone have any tips for me?
Cheers!
You are setting the whole container to z-index: 999, this element .contentContainer contains also the video element. So I would put z-index only on the text containers alone with non-static position in order z-index to take effect.
.video_container .contentContainer {
position: absolute;
width: 100%;
height:100%;
background:#000;
opacity:0.5;
z-index:999; // not needed
}
.video_container .contentContainer .skipButton {
width:100%;
text-align:center;
position: relative;
z-index: 1000;
}
.video_container .contentContainer .skipButton h1 {
color:#FFF;
text-transform:uppercase;
position: relative;
z-index: 1000;
}