Import CSS from an HTML-file as external CSS - javascript

As the title reads, I want to import an HTML-file as external CSS to a website.
Just hear me out: my problem is that I'm working with a very inconvenient CMS that doesn't let me upload CSS-files no matter what.
I'm able to write CSS inside the page directly via HTML-style-tag but that generates a lot of text on every site and also makes maintaining CSS tedious.
As I can't upload CSS-files, I thought maybe I can create a dummy-site inside the CMS with only CSS in it and then later import that site as CSS.
The idea was: when parsed, the HTML of the site (header, body, etc.) will just be skipped (as when CSS has i.e. type-errors) while any valid CSS found is going to be imported.
Now when I try importing this website with
<style type="text/css"> #import url(dummyCSSWebsiteURL); </style>
(as the CMS also doesn't grant me access to the header of a page),
I - of course - get the error:
"Resource interpreted as Stylesheet but transferred with MIME type text/html"
as I am obviously requesting an HTML-file and not CSS.
I also tried jQuery to simply include all the dummy-HTML into an element (that I would have just not displayed):
$("#cssDummy").load(dummyCSSWebsiteURL);
but I get 2 errors that are probably just showing what a horribly inefficient idea this is:
Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience
A parser-blocking, cross site (i.e. different eTLD+1) script, ["..."], is invoked via document.write. The network request for this script MAY be blocked by the browser in this or a future page load due to poor network connectivity. If blocked in this page load, it will be confirmed in a subsequent console message.
maybe I am just disregarding (or not understanding) things on a conceptual level at all but I still wonder if there is a workaround for this problem?
EDIT: I found a workaround
Definitely don't recommend. Try using different server as pointed out in the comments if you can.
I used an XMLHttpRequest to get the external site's HTML, then used regEx to match the content of the div on the page that contains the css and - with added style-tags - inserted the matched css into a div on the page.
Code for external site that contains the CSS:
<div id="generalCode">.testBox{background-color: red; min-height: 200px;}</div>
Code on site that imports the external CSS:
<div class="testBox">
</div>
<div id="cssCodeOnPage">
</div>
<script>
// use onload if you want
getCssCode();
function getCssCode(){
// send request to page where div #generalCode contains css
var xhr = new XMLHttpRequest();
xhr.open('GET', dummyCSSWebsiteURL);
xhr.onload = function(){
// use regex to separate css from rest of html
var re = /<div id="generalCode">([\s\S]*?)<\/div>/;
var cssString = xhr.response.match(re)[1];
cssString = "<style>" + cssString +"</style>";
// insert css into div
var cssDivOnPage = document.getElementById('cssCodeOnPage');
cssDivOnPage.innerHTML = cssString;
}
xhr.send();
}
(sorry for this monstrosity of a question..)

I think the best option is to load that HTML page into an iframe, query the styles out of hte iframe, and then attach that to the current document. I created a live example on Glitch here.
Nothing but the <style> block will be copied from the HTML. The external HTML document does need to be an actual HTML document though (<html><head><style>....), otherwise the page won't be queryable to retrieve the CSS.
This is an example in plain JavaScript:
// Create an iframe
const iframe = document.createElement("iframe");
// Make it not visible
iframe.style.visibility = "hidden";
// This will run once the HTML page has loaded in the <iframe>
iframe.onload = () => {
// Find the <style> element in the HTML document
const style = iframe.contentDocument.querySelector("style");
// Take that <style> element and append it to the current document's <head>
document.querySelector("head").appendChild(style);
// Remove the <iframe> after we are done.
iframe.parentElement.removeChild(iframe);
};
// Setting a source starts the loading process
iframe.src = "css.html";
// The <iframe> doesn't actually load until it is appended to a document
document.querySelector("body").appendChild(iframe);

Its possible in a different way. However not through JS, but PHP include
For that however, your server needs to support PHP and need to use PHP instead of HTML as documents. Sounds more complicated now then it actually is. To use PHP the document has to becalled .php at the end instead of .html e.g. index.php.
The document itself can be written the very same way as you write HTML websites.
Now for the issue to use PHP include. you inlcude the CSS as head style:
index.php:
<html>
<head>
<?php
include('styles.css');
?>
</head>
<body>
content
</body>
</html>
the line <?php include('url'); ?> will load a file mentioned in the url server sided into the document. Therefor you only need to create another file with the name styles.css and write your css in there the normal way.

You Do
<link rel="stylesheet" href="css/style.css">

Related

Localizing html content in vue

So I have been using v-html tag to render the html in my vue pages.
But I encountered a string which was a proper html file and it contained text kind of like this:
<html xmlns="https://www.w3.org/1999/xhtml">
<head>
....
<style>
</style>
</head>
<body style="....">
</body>
</html>
The problem is, I have the v-html on a div, but this code starts affecting the whole page and adds its styling to the whole page and not only to that specific div.
I tried adding "scope" to the style tags but it did not work. Maybe because there's also a style inline tag on body?
I need to find a way to make the html affect only on the div it is on, and not the whole page.
Your best bet would probably be to have a better control over the HTML added using v-html. I would suggest to parse it before and keep only the <body> tag. You could do it using a regex, but it would be easier using a dom parser lib. Example with DomParser:
const DomParser = require("dom-parser");
const parser = new DomParser();
export default {
// ...
computed: {
html() {
const rawHtml = "<html><body><div>test</div></body></html>"; // This data should come from your server
const dom = parser.parseFromString(rawHtml);
return dom.getElementsByTagName("body")[0].innerHTML;
}
}
}
Please note that it is an oversimplified solution as it does not handle the case where there is no <body> tag.
First, you should be very careful when using external HTML with v-html as it can make your site vulnerable to various sorts of attacks (see Vue docs).
Now if you trust the HTML source, other problem is how to embed it without affecting your own side. There is special element for this case, <iframe> - it is not without risk and you should definitely read a bit on how to make it safe but it should solve your problem because is "sandbox" external HMTL so it does not affect your site.
https://developer.mozilla.org/en-US/docs/Learn/HTML/Multimedia_and_embedding/Other_embedding_technologies

Is it possible to do some client-side DOM manipulation before document ready?

I am trying to find a way (if possible) to use javascript to add some attributes to an element at render time and before the DOM is fully loaded. I know, that sounds counterproductive, but let me give you some background:
I'm working in an extremely limited templating platform that gives me access to some page variables, but they need some minor string manipulation. I can't leverage any of the ASP preprocessing so it has to happen on the client-side.
Specifically, I am trying to add Schema.org Microdata markup to an element before Googlebot scans through the document contents.
Essentially I need to modify an attribute value from $5.99 to 5.99.
Here's my most recent attempt, which makes the DOM modifications correctly, but not before Google's rich snippet validator processes the page:
<div class="pitinfo"><div class="padleft padright"><%Product.BasePrice%></div></div>
<!-- at page bottom -->
<script type="text/javascript">
(function() {
var pricesting = "<%Product.BasePrice%>";
var price = pricesting.slice(1);
$('.pitinfo').attr('itemprop', 'price');
$('.pitinfo').attr('content', price);
})();
</script>
After load I get this <div class="pitinfo" itemprop="price" content="9.99">$9.99</div>, however the Rich Snippet Testing tool tells me price is not set.
I have already tried using ASP in my template code but the hosting provider does not allow it.
Is it possible to make the DOM modifications sometime in the middle of the document rendering flow?
It is possible to insert a <script> tag inside of the <body>. JavaScript inside of the tag is loaded before the HTML after it, so you would be able to edit the element's value before the rest of the HTML/JS is loaded.
For example:
<div>
<div id="element" value="$5.99"></div>
<script>
var element = document.getElementById("element")
element.value = 5.99;
</script>
</div>
You can check it out here

Print Javascript in Javascript?

I am in the process of making an addon for a software that basically allows you to have 'responsive' adverts, by checking the page size with javascript and then outputting the relevant ad code to the screen.
This works fine for text ad codes, however I've hit a snag when the ad code is javascript - I can't get the user-provided javascript to output to the page and be executed.
Is this possible at all?
Here is some example code:
<div id="admanagerresponsive">
<script type="text/javascript">
adUnit = document.getElementById("admanagerresponsive");
adWidth = adUnit.offsetWidth;
if (adWidth >= 728) {
<output ad code>
}
</script>
</div>
The code above will be directly in the page.
Is such a thing possible?
EDIT:
could be any advertiser's code, such as adsense. It'll be user provided, and will be standard html. However, it could contain tags, and these will need to be rendered and outputted correctly...
If you really need to inject add html code containing script tags and you are award of the security problems, i suggest to use a library like jQuery that takes care about the cross browser issues with executing <script> tags added later.
Additionally you need to take care about various pitfalls like:
Html paring is done before script parsing, so no matter where a </script> appears this will immediately end your script.
The examples are important for the situations where you have that code as inline script inside your html page.
Example 1:
<script>
adUnit = document.getElementById("admanagerresponsive");
adWidth = adUnit.offsetWidth;if (adWidth >= 728) {
// if you add </script> <b>this is visible as html</b> and everything below is not script anymore
}
</script>
Example 2:
<script>
adUnit = document.getElementById("admanagerresponsive");
adWidth = adUnit.offsetWidth;if (adWidth >= 728) {
var string = "<script> var test;</script>";//the same problem here everything behind the closing script tag is html and not script anymore
}
</script>
So if you need to have some script to inject there you need to make the </script> not to be detectable by the html parser:
<script>
adUnit = document.getElementById("admanagerresponsive");
adWidth = adUnit.offsetWidth;if (adWidth >= 728) {
var string = "<script> var test;</sc"+"ript>";//that way the html parser does not detect the closing script tag
}
</script>
A better solution is not to use inline script at all, not only for that reason, but because you should always keep css, js and html separated.
Break it into two ideas. From your HTML above, just call a js function you wrote somewhere else. Initially have that js function be an alert, to verify that works.
Once that works, you have the problem: how can I get custom js for a page? The answer to that is hopefully that you can create and load a (one-off, custom) js file the same way you create an html file. Or, libraries such as now.js could help. Or, there is a script portion of your html page that you understand how to assemble to include the js.
You could even preload all your size possibilities, then have the js routine from the first paragraph pick the right routine to call,

Most secure javascript JSON Inline technique

I'm using varnish+esi to return external json content from a RESTFul API.
This technique allows me to manage request and refresh data without using webserver resources for each request.
e.g:
<head>
....
<script>
var data = <esi:include src='apiurl/data'>;
</script>
...
After include the esi varnish will return:
var data = {attr:1, attr2:'martin'};
This works fine, but if the API returns an error, this technique will generate a parse error.
var data = <html><head><script>...api js here...</script></head><body><h1 ... api html ....
I solved this problem using a hidden div to parse and catch the error:
...
<b id=esi-data style=display:none;><esi:include src='apiurl/data'></b>
<script>
try{
var data = $.parseJSON($('#esi-data').html());
}catch{ alert('manage the error here');}
....
I've also tried using a script type text/esi, but the browser renders the html inside the script tag (wtf), e.g:
<script id=esi-data type='text/esi'><esi:include src='apiurl/data'></script>
Question:
Is there any why to wrap the tag and avoid the browser parse it ?
Let me expand upon the iframe suggestion I made in my comment—it's not quite what you think!
The approach is almost exactly the same as what you're doing already, but instead of using a normal HTML element like a div, you use an iframe.
<iframe id="esi-data" src="about:blank"><esi:include src="apiurl/data"></iframe>
var $iframe = $('#esi-data');
try {
var data = $.parseJSON($iframe.html());
} catch (e) { ... }
$iframe.remove();
#esi-data { display: none; }
How is this any different from your solution? Two ways:
The data/error page are truly hidden from your visitors. An iframe has an embedded content model, meaning that any content within the <iframe>…</iframe> tags gets completely replaced in the DOM—but you can still retrieve the original content using innerHTML.
It's valid HTML5… sort-of. In HTML5, markup inside iframe elements is treated as text. Sure, you're meant to be able to parse it as a fragment, and it's meant to contain only phrasing content (and no script elements!), but it's essentially just treated as text by the validator—and by browsers.
Scripts from the error page won't run. The content gets parsed as text and replaced in the DOM with another document—no chance for any script elements to be processed.
Take a look at it in action. If you comment out the line where I remove the iframe element and inspect the DOM, you can confirm that the HTML content is being replaced with an empty document. Also note that the embedded script tag never runs.
Important: this approach could still break if the third party added an iframe element into their error page for some reason. Unlikely as this may be, you can bulletproof the approach a little more by combining your technique with this one: surround the iframe with a hidden div that you remove when you're finished parsing.
Here I go with another attempt.
Although I believe you already have the possibly best solution for this, I could only imagine that you work around it with a fairly low-performance method of calling esi:insert in a separate HTML window, then retrieve the contents as if you were using AJAX on the server. Perhaps similar to this? Then check the contents you retrieved, maybe by using json_decode and on success generate an error JSON string.
The greatest downside I see to this is that I believe this would be very consuming and most likely even delays your requests as the separate page is called as if your server yourself was a client, parsed, then sent back.
I'd honestly stick to your current solution.
this is a rather tricky problem with no real elegant solution, if not with no solution at all
I asked you if it was an HTML(5) or XHTML(5) document, because in the later case a CDATA section can be used to wrap the content, changing slightly your solution to something like this :
...
<b id='esi-data' style='display:none;'>
<![CDATA[ <esi:include src='apiurl/data'> ]]>
</b>
<script>
try{
var data = $.parseJSON($('#esi-data').html());
}catch{ alert('manage the error here');}
....
Of crouse this solution works if :
you're using XHTML5 and
the error contains no CDATA section (because CDATA section nesting is impossible).
I don't know if switching from one serialization to the other is an option, but I wanted to clarify the intent of my question. It will hopefully help you out :).
Can't you simply change your API to return JSON { "error":"error_code_or_text" } on error? You can even do something meaningful in your interface to alert user about error if you do it that way.
<script>var data = 999;</script>
<script>
data = <esi:include src='apiurl/data'>;
</script>
<script>
if(data == 999) alert("there was an error");
</script>
If there is an error and "data" is not JSON, then a javascript error will be thrown. The next script block will pick that up.

Static content in website

I've got a website and I'd like to make a part of it static. What happens is that the header, the menu bar and the footer are consistent in every page. I'd like to have them always loaded and when I click the menu button, it will only reload what is the body of the site.
Is there a simple chunck of code that can early achieve this? Something in js or ajax? I'm sorry but I don't have enough experience in these languages to accomplish something on my own. I've already tried to check jQuery library but it's still pretty confusing to me.
Thank you.
I think you don't even need Ajax or css!! Just use iFrames!! They are awesome, what happens is that u only design one page as the holder of your static content (Header-Menu ...) and put one iFrame in there as a place holder for any page you want to load in it, u should use proper css code to place the iFrame where you want, now, for every link in your menu, just set the "target" attribute equal to your iFrame's name and all the links will be loaded in that iFrame and your page won't be reloaded with every link click... I'll be back with some code...
Just add in every page a div container with ID for header, menubar and footer and just load it with this:
$(document).ready(function(){
$('#header').load('header.html');
$('#menubar').load('menubar.html');
$('#footer').load('footer.html');
});
Just make sure that the html files don't have html, head or body tags within, only the HTML-Code you would write inside the div. It's just like the include function in PHP.
EDIT:
For easy and simple implementation store the code above inside a .js file (e.g. include.js) and add this inside every head just below the include of all other scripts of your html files:
<script type="text/javascript" src="include.js"></script>
EDIT2:
Another solution ist to load the content of the page instead of the header, menubar, footer.
Here you take the same specifications (no html, body, etc. tags inside your content html files)
Name your content div e.g. <div id="content"></div>
Your navbar for example:
<div id="navbar">
Content1
Content2
</div>
JavaScript Code:
$(document).ready(function() {
//Click on a link that's child of the navbar
$('#navbar > a').click(function() {
//Get the html file (e.g. content1.html)
var file = $(this).attr('href');
//Load this file into the #content
$('#content').load(file);
return false;
});
});
You should consider the use of Server Side Included : http://httpd.apache.org/docs/current/howto/ssi.html
It's not quite easy to understand (as it refer to apache configuration), but this is a really great solution.
In a nutshell, you include parts of html code in you main page :
<!--#include virtual="/footer.html" -->
You won't have to use or understand all JQuery Framewol, user agent won't have to parse (if they are able to !) Javascript.
This is a pretty good replacement of PHP / ASP / Java for this kind of purpose.
You could use ajax to request the body of each page. But this is only one possibility - there are many. An other approach could be to create you page content using a script language (php, perl) serverside and employ a function there which adds footer, header and anything else to each page.
If you have an idea of Jquery then use click event on menu links to load the page in a div like the following syntax may help you.
$(document).ready(function(){
$("a.menu").click(function(){
$("#bodyContent").load("http://abc.com/your-linked-page.html");
});
});
To load the url dynamically use the following code:
In your menu bar the link looks like:
Home
In your Jquery code:
$(document).ready(function(){
$("a.menu").click(function(){
url = $(this).attr("title"); // here url is just a variable
$("#bodyContent").load(url);
});
});
Step 1: Add Jquery file into your html page.
Step 2: Use the above jquery code and change your menu link to the new what i said here.
Step 3: If you done it correctly, It will work for you.
How about a traditional iframe?
In your menu:
<a target="body" href="URL_to_your_Menu1_page">Menu1</a>
and then further in the document:
<iframe name="body" src="URL_to_homepage"></iframe>
You may use frameset and frames and organize you pages accordingly. So, frames containing menus can always be at display and while displaying contents on click of menu u may set target to frame in which you would like to load the contents.

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