Embed a base64-encoded image at the bottom of HTML file - html

I have an HTML file like this:
<html>
<body>
<p>Some text...</p>
<img src="data:image/png;base64
<!-- Some really ugly base64 -->
">
<p>Some text...</p>
</body>
</html>
By default, a base64-encoded file really clutters an HTML document.
I am wondering, if there is a method to have an image that links to another place at the HTML file, rather than pasting the base64 directly between the important content, to improve readability in the raw file. I know, this is possible with some kind of JavaScript solution, but I would prefer not to use it.

Inspired by this answer, it is possible to specify image contents via CSS using the all-purpose content attribute.
I do not know which browsers support this behaviour, although I strongly suspect most modern ones do.
Example modified from that answer:
<img src="#" class="myImage" />
<style type="text/css">
.myImage {
content: url('data:image/gif;base64,R0lGODlhEAAQALMPAAAAAIAAAACAAICAAAAAgIAAgACAgMDAwICAgP8AAAD/AP//AAAA//8A/wD//////yH5BAEAAA8ALAAAAAAQABAAQAQ78EkJqp10LaB759sDVh4ZiqVVTqC3om6smVvcAmz74Zioz7zMRmfC/WTAGXI0Ws5gtc+HhXz2fJagJAIAOw==');
}
</style>
Placing style elements in the body is illegal in HTML4, and dubious in HTML 5. However, every browser I know of supports it.
Remember that having inline images in HTML documents comes with some massive downsides, most prominently impaired cacheability.

Related

Is there a smart way to hide alot of text in HTML?

so I have this huge amount of text from several documents that i'd like to insert on my webpages. When i copy paste the text into my <p>element, it works fine and all, but it looks messy in my html-file.
Is there any other way to transfer my written document to my html-file, for instance link the document to the html-file, or maybe there's a way to hide or separate the <p> so the html-file looks neat even though there's a huge amount of text in my html-file. Any advice?
I do not know about any way to include html in another html (something like php's include), but it could be done with JQuery:
index.html:
<html>
<head>
<!-- link jquery -->
<script>
$(function(){
$("#fileContent").load("doc.html");
});
</script>
</head>
<body>
<div id="fileContent"></div>
</body>
</html>
doc.html (file that contains your text)
There's a lot you could do to separate these blocks of text.
Firstly, I'd recommend using <div>..</div> tags to divide the content into separate semantic sections. There are a bunch of different tags that aim to divide the content of the page semantically: <aside>, <main>, <header>, <nav>, and so on. I'd recommend reading up on these tags and using them appropriately.
However, to answer your question more directly, you should separate each block of text into separate <p> tags. After all, the <p> tag is meant for defining separate paragraphs. While the HTML document may not look pretty when indented and filled with multiple different tags like <div> a <p>, it is the best way to do it.
Unless the HTML page is going to be presented in its core (code) format, then how the <p> tags look in the .html file is unnecessary because after all these are what define how the page is presented and rendered in the browser.

How to Isolate some part of HTML code style & formatting? [duplicate]

I am trying to figure out a way to display an archive of email newsletters on my client's site. The issue is that the newsletters are full of a zillion inline styles, which is great for seeing them in Outlook or wherever, but they're not looking too hot in an otherwise-nicely styled site.
My goal is for my client to be able to copy the entire source code of a generated newsletter (which her list management company* gives her access to) and paste it into the CMS (drupal, if it makes a difference).
*Constant Contact? Mail Chimp? I forget. One of those.
Then I'd like to display it on her site, inside the basic structure (header, nav, etc) of the rest of the site. If this was 1997, I'd say "iframes!" and be done with it, but A) that seems like a lame solution, and B) the code doesn't actually exist on a page by itself, which I think is required for iframes.
Is there some kind of tag I can put around this block of HTML to isolate it from the rest of the site's styles? Or is there another way to go about this entirely?
Thanks!
IFrames are the only way to go that I've ever been able to find. The only alternative to this would be to override every style in the parent page's CSS for the newsletter display area.
As you noted, using an iframe will probably require you to host the newsletters in an independent file. The only alternative to this that I'm aware of is that you can use JavaScript to dynamically create and/or populate the iframe.
If you go with this method, you could have the newsletter present in a div with a specific class, and then use JavaScript to move the div into an iframe. The big downside being that this wouldn't happen for users without JavaScript enabled.
9 years later and there still isn't a better solution.
If you don't have an external source (you can't add html into a frame manually) you need to use js to insert the messy html/css (in my case I use it to view emails)
<iframe class="my-frame" width="100%" height="100%" src="about:blank"></iframe>
and js:
const frame = document.querySelector('.my-frame');
frame.contentWindow.document.open('text/html', 'replace');
frame.contentWindow.document.write(hereGoesYourMessyHtmlCss);
frame.contentWindow.document.close();
Is there a reason why you can't use a modal? That would allow you to force a new request and make the page render how you'd want it to by not applying your general stylesheet while at the same time keeping your user on the desired page. Of course, it doesn't display the element inline so-to-speak, but it's nearly functionally equivelent.
Cutting and pasting raw HTML presents too many security problems, in my opinion. Never trust user's input. Even when the content is entirely benign, next week the designer of newsletter might decide to change their formatting or incorporate some javascript and you'll be responsible for anything that might go wrong.
Therefore I would implement a parser that would drop anything but the content part and leave only b, a, h*, blockquote and similar simple elements, like the ones allowed in forum posts, as well as their styles. After that, you can display it as a normal post in a CMS. I don't see any reason why that should look differently.
As for how to isolate that from your other CSS, you don't really need to if you are careful that all of CSS rules of your CMS apply to elements with specific classes. Alternatively, do a CSS reset for your posts:
.post p {
margin: 0;
...
.post /* all the standard CSS reset rules preceded with .post */
and then
<div class="post"> content parsed from your CMS </div>
Another option that I haven't used myself but am looking to possibly leverage in a similar situation is to use the Shadow DOM which is part of the Web Components spec. My main concern is that we still have some user's using IE 11 and while there seems to be support for polyfills it doesn't look like covering all browser's is real straight forward based on what I've read elsewhere.
Some details on how to use Shadow DOM to this effect can be found here and here. I've also created a small gist that I've created to demonstrate basic idea that I've been formulating as I learn about how the Shadow DOM works which I'll be updating as I learn more. Below you can see a snapshot of the content of that gist.
<!doctype html>
<html>
<head>
<style>
.row {
display: flex;
}
.column {
flex: 50%;
padding: 10px;
height: 300px;
}
* {
color: Red;
}
</style>
</head>
<body>
<div class="row">
<div class="column" style="background-color:#aaa;">
<h2>Column 1</h2>
<div id="content1">
SOME CONTENT FROM CMS
</div>
</div>
<div class="column" style="background-color:#bbb;">
<h2>Column 2</h2>
<div id="content2">
SOME MORE CONTENT FROM CMS
</div>
</div>
</div>
<script>
document
.getElementById("content1")
.attachShadow({ mode: 'open' })
.innerHTML = `
<style>
*{all:initial}
style{display: none}
div{display: block}
</style>
<h3>This text is not red</h3>
<div>slot content: <slot></slot></div>`;
document
.getElementById("content2")
.attachShadow({ mode: 'open' })
.innerHTML = `
<style>
*{all:initial}
style{display: none}
div{display: block}
</style>
<h3>This text is not red</h3>
<div>slot content: <slot></slot></div>`;
</script>
</body>
</html>

What is the semantic HTML tag to display for URLs that are not links?

I have a search engine plugin that outputs results in a basic structure:
<a href="page url">
<div class="searchResult">
<h3>Page title</h3>
<p>Page url</p>
<p>Page <meta> description</p>
</div>
</a>
The plugin is designed to integrate into an existing website so it has no default styling. However, websites are supposed to be usable even without CSS through the use of the correct, semantic HTML tags. Currently the displayed URL is indistinguishable from the description and would appear as a software glitch without additional styling.
Google uses the <cite> tag, however in HTML 5 <cite> should be used for the title of a work, not a URL so this isn't the answer.
Is there a HTML tag that is designed to show a URL other than <a>, a URL that is not clickable? What is the semantic approach for this?
If I understand you correctly, you want the url to be a link but also display as a url. To do this put the url in the a tag twice, like so:
This can then be style as desired by the destination page.
<style>
a {
color: blue;
text-decoration: underline; }
</style>
http://www.google.com/<br /><br />
Edited to add:<br /><br />
<a>http://www.google.com/</a>
The href attribute is required for default link styling.
Since adding css seems to be an issue I doubt you can use JS but if you can here's a solution that requires the css class .do-not-open to prevent links from opening.

How to add 1 pure html in another html

I am having 1 pure html page for ex. sample.html. I need to include this html into another pure html for ex.Orginal.html.How to do this? I am having a header image in my sample.html.It should come at the top of the Orginal.html page.
If you're using Apache web server, you could try using server side includes.
You can't do such things in pure HTML, unless you use frames or iframe element. But better merge them by hand...
Here is an example of how to do it in pure HTML with an iframe, which although strangely not mentioned in HTML 4 specification is supported by all major browsers (and is in the HTML 5 specification)
<body>
<h1>This is original page</h1>
<p>Some content on original page.</p>
<iframe src="sample.html" width="600" height="300"></iframe>
</body>
You can adjust the width and height and you can also remove the border if you want the page to be more seamless.
Be wary of JavaScript solutions to this problem, especially if you want to be viewed on mobile devices.
Additional note: Avoid frameset solutions also, as they aren't valid markup.
See Include One File In Another, which has a summary of the various techniques that are available (along with their pros and cons).
You could use JavaScript to load some HTML from one document into another. This task is fairly simple using the jQuery toolkit:
$("The ID of a container (a div element for instance) in which you want to load
the contents of a HTML file").load("path to html file you want to load");
<div id="inserthere" />
$(function ()
{
$("#inserthere").load("loadme.html"); // Load the contents of loadme.html
// and stuff it in the div with the
// ID of "inserthere"
});

Any way to display some heavily-styled HTML in isolation from the rest of site's styles?

I am trying to figure out a way to display an archive of email newsletters on my client's site. The issue is that the newsletters are full of a zillion inline styles, which is great for seeing them in Outlook or wherever, but they're not looking too hot in an otherwise-nicely styled site.
My goal is for my client to be able to copy the entire source code of a generated newsletter (which her list management company* gives her access to) and paste it into the CMS (drupal, if it makes a difference).
*Constant Contact? Mail Chimp? I forget. One of those.
Then I'd like to display it on her site, inside the basic structure (header, nav, etc) of the rest of the site. If this was 1997, I'd say "iframes!" and be done with it, but A) that seems like a lame solution, and B) the code doesn't actually exist on a page by itself, which I think is required for iframes.
Is there some kind of tag I can put around this block of HTML to isolate it from the rest of the site's styles? Or is there another way to go about this entirely?
Thanks!
IFrames are the only way to go that I've ever been able to find. The only alternative to this would be to override every style in the parent page's CSS for the newsletter display area.
As you noted, using an iframe will probably require you to host the newsletters in an independent file. The only alternative to this that I'm aware of is that you can use JavaScript to dynamically create and/or populate the iframe.
If you go with this method, you could have the newsletter present in a div with a specific class, and then use JavaScript to move the div into an iframe. The big downside being that this wouldn't happen for users without JavaScript enabled.
9 years later and there still isn't a better solution.
If you don't have an external source (you can't add html into a frame manually) you need to use js to insert the messy html/css (in my case I use it to view emails)
<iframe class="my-frame" width="100%" height="100%" src="about:blank"></iframe>
and js:
const frame = document.querySelector('.my-frame');
frame.contentWindow.document.open('text/html', 'replace');
frame.contentWindow.document.write(hereGoesYourMessyHtmlCss);
frame.contentWindow.document.close();
Is there a reason why you can't use a modal? That would allow you to force a new request and make the page render how you'd want it to by not applying your general stylesheet while at the same time keeping your user on the desired page. Of course, it doesn't display the element inline so-to-speak, but it's nearly functionally equivelent.
Cutting and pasting raw HTML presents too many security problems, in my opinion. Never trust user's input. Even when the content is entirely benign, next week the designer of newsletter might decide to change their formatting or incorporate some javascript and you'll be responsible for anything that might go wrong.
Therefore I would implement a parser that would drop anything but the content part and leave only b, a, h*, blockquote and similar simple elements, like the ones allowed in forum posts, as well as their styles. After that, you can display it as a normal post in a CMS. I don't see any reason why that should look differently.
As for how to isolate that from your other CSS, you don't really need to if you are careful that all of CSS rules of your CMS apply to elements with specific classes. Alternatively, do a CSS reset for your posts:
.post p {
margin: 0;
...
.post /* all the standard CSS reset rules preceded with .post */
and then
<div class="post"> content parsed from your CMS </div>
Another option that I haven't used myself but am looking to possibly leverage in a similar situation is to use the Shadow DOM which is part of the Web Components spec. My main concern is that we still have some user's using IE 11 and while there seems to be support for polyfills it doesn't look like covering all browser's is real straight forward based on what I've read elsewhere.
Some details on how to use Shadow DOM to this effect can be found here and here. I've also created a small gist that I've created to demonstrate basic idea that I've been formulating as I learn about how the Shadow DOM works which I'll be updating as I learn more. Below you can see a snapshot of the content of that gist.
<!doctype html>
<html>
<head>
<style>
.row {
display: flex;
}
.column {
flex: 50%;
padding: 10px;
height: 300px;
}
* {
color: Red;
}
</style>
</head>
<body>
<div class="row">
<div class="column" style="background-color:#aaa;">
<h2>Column 1</h2>
<div id="content1">
SOME CONTENT FROM CMS
</div>
</div>
<div class="column" style="background-color:#bbb;">
<h2>Column 2</h2>
<div id="content2">
SOME MORE CONTENT FROM CMS
</div>
</div>
</div>
<script>
document
.getElementById("content1")
.attachShadow({ mode: 'open' })
.innerHTML = `
<style>
*{all:initial}
style{display: none}
div{display: block}
</style>
<h3>This text is not red</h3>
<div>slot content: <slot></slot></div>`;
document
.getElementById("content2")
.attachShadow({ mode: 'open' })
.innerHTML = `
<style>
*{all:initial}
style{display: none}
div{display: block}
</style>
<h3>This text is not red</h3>
<div>slot content: <slot></slot></div>`;
</script>
</body>
</html>