Change CSS locally per domain - html

I want to add CSS to pages with a certain URL in much the same way that Greasemonkey adds JavaScript. I guess I could inject some CSS with a script, but that isn't as clean.
Are there any browser plugins that let me do this? It doesn't necessarily need to be a Firefox one.

There's the Stylish add-on for Firefox. It supports global, per-domain, and per-URL user stylesheets. It seems to work well for what I use it for, although I admittedly haven't played around with it very seriously.

If you have access to jQuery, you could do this pretty easily:
var css_href = "path to css";
var head = document.getElementsByTagName('head')[0];
$(document.createElement('link'))
.attr({ type: 'text/css',
href: css_href,
rel: 'stylesheet,
media: 'screen''})
.appendTo(head);
[Source]
This can also be done pretty easily with vanilla JavaScript:
function addStyle(style) {
var head = document.getElementsByTagName("HEA­D")[0];
var ele = head.appendChild(window.document.c­reateElement( 'style' ));
ele.innerHTML = style;
return ele;
}
addStyle('#import "/URL/TO/STYLESHEET;"');
[Source] (Apparently from "Dive into Greasemonkey" by Mark Pilgrim originally)
You might want to make sure your styles have !important declarations though.
Having said that, it should be easy to remove the existing stylesheets this way too and perhaps even iterate elements and remove inline styles.

Related

CSS conflict when using iFrame [duplicate]

Is it possible to change styles of a div that resides inside an iframe on the page using CSS only?
You need JavaScript. It is the same as doing it in the parent page, except you must prefix your JavaScript command with the name of the iframe.
Remember, the same origin policy applies, so you can only do this to an iframe element which is coming from your own server.
I use the Prototype framework to make it easier:
frame1.$('mydiv').style.border = '1px solid #000000'
or
frame1.$('mydiv').addClassName('withborder')
In short no.
You can not apply CSS to HTML that is loaded in an iframe, unless you have control over the page loaded in the iframe due to cross-domain resource restrictions.
Yes. Take a look at this other thread for details:
How to apply CSS to iframe?
const cssLink = document.createElement("link");
cssLink.href = "style.css";
cssLink.rel = "stylesheet";
cssLink.type = "text/css";
frames['frame1'].contentWindow.document.body.appendChild(cssLink);
// ^frame1 is the #id of the iframe: <iframe id="frame1">
You can retrieve the contents of an iframe first and then use jQuery selectors against them as usual.
$("#iframe-id").contents().find("img").attr("style","width:100%;height:100%")
$("#iframe-id").contents().find("img").addClass("fancy-zoom")
$("#iframe-id").contents().find("img").onclick(function(){ zoomit($(this)); });
Good Luck!
The quick answer is: No, sorry.
It's not possible using just CSS. You basically need to have control over the iframe content in order to style it. There are methods using javascript or your web language of choice (which I've read a little about, but am not to familiar with myself) to insert some needed styles dynamically, but you would need direct control over the iframe content, which it sounds like you do not have.
Use Jquery and wait till the source is loaded,
This is how I have achieved(Used angular interval, you can use javascript setInterval method):
var addCssToIframe = function() {
if ($('#myIframe').contents().find("head") != undefined) {
$('#myIframe')
.contents()
.find("head")
.append(
'<link rel="stylesheet" href="app/css/iframe.css" type="text/css" />');
$interval.cancel(addCssInterval);
}
};
var addCssInterval = $interval(addCssToIframe, 500, 0, false);
Combining the different solutions, this is what worked for me.
$(document).ready(function () {
$('iframe').on('load', function() {
$("iframe").contents().find("#back-link").css("display", "none");
});
});
Apparently it can be done via jQuery:
$('iframe').load( function() {
$('iframe').contents().find("head")
.append($("<style type='text/css'> .my-class{display:none;} </style>"));
});
https://stackoverflow.com/a/13959836/1625795
probably not the way you are thinking. the iframe would have to <link> in the css file too. AND you can't do it even with javascript if it's on a different domain.
Not possible from client side . A javascript error will be raised "Error: Permission denied to access property "document"" since the Iframe is not part of your domaine.
The only solution is to fetch the page from the server side code and change the needed CSS.
A sort of hack-ish way of doing things is like Eugene said. I ended up following his code and linking to my custom Css for the page. The problem for me was that, With a twitter timeline you have to do some sidestepping of twitter to override their code a smidgen. Now we have a rolling timeline with our css to it, I.E. Larger font, proper line height and making the scrollbar hidden for heights larger than their limits.
var c = document.createElement('link');
setTimeout(frames[0].document.body.appendChild(c),500); // Mileage varies by connection. Bump 500 a bit higher if necessary
Just add this and all works well:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
If the iframe comes from another server, you will have CORS ERRORS like:
Uncaught DOMException: Blocked a frame with origin "https://your-site.com" from accessing a cross-origin frame.
Only in the case you have control of both pages, you can use https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage to safely send messages like this:
On you main site(one that loads the iframe):
const iframe = document.querySelector('#frame-id');
iframe.contentWindow.postMessage(/*any variable or object here*/, 'https://iframe-site.example.com');
on the iframe site:
// Called sometime after postMessage is called
window.addEventListener("message", (event) => {
// Do we trust the sender of this message?
if (event.origin !== "http://your-main-site.com")
return;
...
...
});
Yes, it's possible although cumbersome. You would need to print/echo the HTML of the page into the body of your page then apply a CSS rule change function. Using the same examples given above, you would essentially be using a parsing method of finding the divs in the page, and then applying the CSS to it and then reprinting/echoing it out to the end user. I don't need this so I don't want to code that function into every item in the CSS of another webpage just to aphtply.
References:
Printing content of IFRAME
Accessing and printing HTML source code using PHP or JavaScript
http://www.w3schools.com/js/js_htmldom_html.asp
http://www.w3schools.com/js/js_htmldom_css.asp

Override all CSS styles for block

I'm using HTML examples on my website (using Crayon) and want to show output as well.
But I want the output to show as pure as it would have without any of my website's own stylesheets.
I can of course do this with an iframe, but that seems tedious. Is there perhaps another trick or library that anyone is aware of?
Thanks
Ended up doing this. Works well...
$('.crayon-title').click(function() {
var content = $(this).parent().siblings('.crayon-plain-wrap').children('textarea').text();
var x=window.open();
x.document.open();
x.document.write(content);
x.document.close();
})

Dynamically load stylesheets

i know that you can have style-sheets in the head of a page, but i like to have them in a separate file. Now i'm working with a single page application.
Well in an SPA the content is dynamic, right? so i didn't want to import all the style-sheets in the head section with the link tag. Can i somehow import style-sheets as-and-when i need them?
I mean, can i have a link in the body, such that whenever my SPA loads some dynamic content, a style sheet also gets loaded? Such that i dont have to load all the stylesheets even when the dynamic content is not loaded..
I stress again: Whenever the content loads, the styles load.
I know i can do it with the help of an inline style like this:
~PSEUDO CODE
<tagname style="somestyle"></tagname>
but can i have some dynamic file imports too? Can i have the link tag in the body too? Even if it works, is it standard?
You should look into asychronously loading assets, such as the famous google-analytics code. You can load external stylesheets using Javascript.
JavaScript
(function(){
var styles = document.createElement('link');
styles.rel = 'stylesheet';
styles.type = 'text/css';
styles.media = 'screen';
styles.href = 'path/to/css/file';
document.getElementsByTagName('head')[0].appendChild(styles);
})();
Lines 1 and 7 create a new scope for variables such that local variables do not collide or override with globally scoped variables. It isn't necessary just a best practice. This solution also assumes you have a <head> tag in your html.
You can add/remove/edit link tags in your head area with java script to add/remove stylesheet files.
Code example:
Add a stylesheet to the head:
var newstyle = document.createElement("link"); // Create a new link Tag
// Set some attributes:
newstyle.setAttribute("rel", "stylesheet");
newstyle.setAttribute("type", "text/css");
newstyle.setAttribute("href", "filename.css"); // Your .css File
document.getElementsByTagName("head")[0].appendChild(newstyle);
To remove or edit a stylesheet you can give every stylesheet an id attribute and access it with this:
document.getElementById('styleid')
Or you can loop through all link tags in the head area and find the correct one but I suggest the solution with the ID ;)
Now you can change the href attribute:
document.getElementById('styleid').setAttribute("href", "newfilename.css");
Or you can remove the complete tag:
var styletorem = document.getElementById('styleid');
styletorem.parentNode.removeChild(styletorem)
I just tried to give dynamic styling to my webpage. I used a button. On click of it, the CSS will get imported using a method in Javascript.
In my html, I have:
<button type="button" onclick="changeStyle()"> CLICK TO SEE THE MAGIC!! </button>
Then in Javascript, I have a method named changeStyle():
function changeStyle()
{
var styles = document.createElement('link');
styles.type="text/css";
styles.rel="stylesheet";
styles.href="./css/style.css";
document.head.appendChild(styles);
}
It worked perfectly.

Can I create links with 'target="_blank"' in Markdown?

Is there a way to create a link in Markdown that opens in a new window? If not, what syntax do you recommend to do this? I'll add it to the markdown compiler I use. I think it should be an option.
As far as the Markdown syntax is concerned, if you want to get that detailed, you'll just have to use HTML.
Hello, world!
Most Markdown engines I've seen allow plain old HTML, just for situations like this where a generic text markup system just won't cut it. (The StackOverflow engine, for example.) They then run the entire output through an HTML whitelist filter, regardless, since even a Markdown-only document can easily contain XSS attacks. As such, if you or your users want to create _blank links, then they probably still can.
If that's a feature you're going to be using often, it might make sense to create your own syntax, but it's generally not a vital feature. If I want to launch that link in a new window, I'll ctrl-click it myself, thanks.
Kramdown supports it. It's compatible with standard Markdown syntax, but has many extensions, too. You would use it like this:
[link](url){:target="_blank"}
I don't think there is a markdown feature, although there may be other options available if you want to open links which point outside your own site automatically with JavaScript.
Array.from(javascript.links)
.filter(link => link.hostname != window.location.hostname)
.forEach(link => link.target = '_blank');
jsFiddle.
If you're using jQuery:
$(document.links).filter(function() {
return this.hostname != window.location.hostname;
}).attr('target', '_blank');
jsFiddle.
With Markdown v2.5.2, you can use this:
[link](URL){:target="_blank"}
So, it isn't quite true that you cannot add link attributes to a Markdown URL. To add attributes, check with the underlying markdown parser being used and what their extensions are.
In particular, pandoc has an extension to enable link_attributes, which allow markup in the link. e.g.
[Hello, world!](http://example.com/){target="_blank"}
For those coming from R (e.g. using rmarkdown, bookdown, blogdown and so on), this is the syntax you want.
For those not using R, you may need to enable the extension in the call to pandoc with +link_attributes
Note: This is different than the kramdown parser's support, which is one the accepted answers above. In particular, note that kramdown differs from pandoc since it requires a colon -- : -- at the start of the curly brackets -- {}, e.g.
[link](http://example.com){:hreflang="de"}
In particular:
# Pandoc
{ attribute1="value1" attribute2="value2"}
# Kramdown
{: attribute1="value1" attribute2="value2"}
^
^ Colon
One global solution is to put <base target="_blank">
into your page's <head> element. That effectively adds a default target to every anchor element. I use markdown to create content on my Wordpress-based web site, and my theme customizer will let me inject that code into the top of every page. If your theme doesn't do that, there's a plug-in
Not a direct answer, but may help some people ending up here.
If you are using GatsbyJS there is a plugin that automatically adds target="_blank" to external links in your markdown.
It's called gatsby-remark-external-links and is used like so:
yarn add gatsby-remark-external-links
plugins: [
{
resolve: `gatsby-transformer-remark`,
options: {
plugins: [{
resolve: "gatsby-remark-external-links",
options: {
target: "_blank",
rel: "noopener noreferrer"
}
}]
}
},
It also takes care of the rel="noopener noreferrer".
Reference the docs if you need more options.
For ghost markdown use:
[Google](https://google.com" target="_blank)
Found it here:
https://cmatskas.com/open-external-links-in-a-new-window-ghost/
I'm using Grav CMS and this works perfectly:
Body/Content:
Some text[1]
Body/Reference:
[1]: http://somelink.com/?target=_blank
Just make sure that the target attribute is passed first, if there are additional attributes in the link, copy/paste them to the end of the reference URL.
Also work as direct link:
[Go to this page](http://somelink.com/?target=_blank)
You can do this via native javascript code like so:
var pattern = /a href=/g;
var sanitizedMarkDownText = rawMarkDownText.replace(pattern,"a target='_blank' href=");
JSFiddle Code
In my project I'm doing this and it works fine:
[Link](https://example.org/ "title" target="_blank")
Link
But not all parsers let you do that.
There's no easy way to do it, and like #alex has noted you'll need to use JavaScript. His answer is the best solution but in order to optimize it, you might want to filter only to the post-content links.
<script>
var links = document.querySelectorAll( '.post-content a' );
for (var i = 0, length = links.length; i < length; i++) {
if (links[i].hostname != window.location.hostname) {
links[i].target = '_blank';
}
}
</script>
The code is compatible with IE8+ and you can add it to the bottom of your page. Note that you'll need to change the ".post-content a" to the class that you're using for your posts.
As seen here: http://blog.hubii.com/target-_blank-for-links-on-ghost/
If someone is looking for a global rmarkdown (pandoc) solution.
Using Pandoc Lua Filter
You could write your own Pandoc Lua Filter which adds target="_blank" to all links:
Write a Pandoc Lua Filter, name it for example links.lua
function Link(element)
if
string.sub(element.target, 1, 1) ~= "#"
then
element.attributes.target = "_blank"
end
return element
end
Then update your _output.yml
bookdown::gitbook:
pandoc_args:
- --lua-filter=links.lua
Inject <base target="_blank"> in Header
An alternative solution would be to inject <base target="_blank"> in the HTML head section using the includes option:
Create a new HTML file, name it for example links.html
<base target="_blank">
Then update your _output.yml
bookdown::gitbook:
includes:
in_header: links.html
Note: This solution may also open new tabs for hash (#) pointers/URLs. I have not tested this solution with such URLs.
In Laravel I solved it this way:
$post->text= Str::replace('<a ', '<a target="_blank"', $post->text);
Not works for a specific link. Edit all links in the Markdown text. (In my case it's fine)
I ran into this problem when trying to implement markdown using PHP.
Since the user generated links created with markdown need to open in a new tab but site links need to stay in tab I changed markdown to only generate links that open in a new tab. So not all links on the page link out, just the ones that use markdown.
In markdown I changed all the link output to be <a target='_blank' href="..."> which was easy enough using find/replace.
I do not agree that it's a better user experience to stay within one browser tab. If you want people to stay on your site, or come back to finish reading that article, send them off in a new tab.
Building on #davidmorrow's answer, throw this javascript into your site and turn just external links into links with target=_blank:
<script type="text/javascript" charset="utf-8">
// Creating custom :external selector
$.expr[':'].external = function(obj){
return !obj.href.match(/^mailto\:/)
&& (obj.hostname != location.hostname);
};
$(function(){
// Add 'external' CSS class to all external links
$('a:external').addClass('external');
// turn target into target=_blank for elements w external class
$(".external").attr('target','_blank');
})
</script>
You can add any attributes using {[attr]="[prop]"}
For example [Google] (http://www.google.com){target="_blank"}
For completed alex answered (Dec 13 '10)
A more smart injection target could be done with this code :
/*
* For all links in the current page...
*/
$(document.links).filter(function() {
/*
* ...keep them without `target` already setted...
*/
return !this.target;
}).filter(function() {
/*
* ...and keep them are not on current domain...
*/
return this.hostname !== window.location.hostname ||
/*
* ...or are not a web file (.pdf, .jpg, .png, .js, .mp4, etc.).
*/
/\.(?!html?|php3?|aspx?)([a-z]{0,3}|[a-zt]{0,4})$/.test(this.pathname);
/*
* For all link kept, add the `target="_blank"` attribute.
*/
}).attr('target', '_blank');
You could change the regexp exceptions with adding more extension in (?!html?|php3?|aspx?) group construct (understand this regexp here: https://regex101.com/r/sE6gT9/3).
and for a without jQuery version, check code below:
var links = document.links;
for (var i = 0; i < links.length; i++) {
if (!links[i].target) {
if (
links[i].hostname !== window.location.hostname ||
/\.(?!html?)([a-z]{0,3}|[a-zt]{0,4})$/.test(links[i].pathname)
) {
links[i].target = '_blank';
}
}
}
Automated for external links only, using GNU sed & make
If one would like to do this systematically for all external links, CSS is no option. However, one could run the following sed command once the (X)HTML has been created from Markdown:
sed -i 's|href="http|target="_blank" href="http|g' index.html
This can be further automated by adding above sed command to a makefile. For details, see GNU make or see how I have done that on my website.
If you just want to do this in a specific link, just use the inline attribute list syntax as others have answered, or just use HTML.
If you want to do this in all generated <a> tags, depends on your Markdown compiler, maybe you need an extension of it.
I am doing this for my blog these days, which is generated by pelican, which use Python-Markdown. And I found an extension for Python-Markdown Phuker/markdown_link_attr_modifier, it works well. Note that an old extension called newtab seems not work in Python-Markdown 3.x.
For React + Markdown environment:
I created a reusable component:
export type TargetBlankLinkProps = {
label?: string;
href?: string;
};
export const TargetBlankLink = ({
label = "",
href = "",
}: TargetBlankLinkProps) => (
<a href={href} target="__blank">
{label}
</a>
);
And I use it wherever I need a link that open in a new window.
For "markdown-to-jsx" with MUI v5
This seem to work for me:
import Markdown from 'markdown-to-jsx';
...
const MarkdownLink = ({ children, ...props }) => (
<Link {...props}>{children}</Link>
);
...
<Markdown
options={{
forceBlock: true,
overrides: {
a: {
component: MarkdownLink,
props: {
target: '_blank',
},
},
},
}}
>
{description}
</Markdown>
This works for me: [Page Link](your url here "(target|_blank)")

Make HTML anchor to a new window in a strict docktype

We use "target" attribute of the tag to specify the target location of the link.
But "target" attribute cannot be used in strict doctype (I referred this at http://w3schools.com/tags/tag_a.asp). So what is the solution if we use strict doctype?
In short, JavaScript.
The strict doctype is loosely considered to be "strictly document content" and not behaviour, which the target attribute defines. It assumes the user will decide and have complete control over how links are opened in their browser.
The solution is to use JavaScript to define how links open. You might use a class or other attribute to have a JS library to force them to open in a new window:
my link
So your script might look like this:
function externalLinks() {
if (!document.getElementsByTagName) return;
var anchors = document.getElementsByTagName("a");
for (var i=0; i<anchors.length; i++) {
var anchor = anchors[i];
if (anchor.getAttribute("href") &&
anchor.getAttribute("rel") == "external")
anchor.target = "_blank";
}
}
window.onload = externalLinks;
This is even easier in jQuery:
$(function(){
$('a[rel=external]').attr('target', '_blank');
});
Either use the transitional doctype, which does allow target, or if you want to open a new window, use JavaScript.
window.open() is the programmatic way to open a new tab if you cannot rely on the default anchor behavior. However, this will get intercepted by many pop-up blockers. Consider an in-document overlay. http://www.javascript-coder.com/window-popup/unblockable-popup.phtml