Menu
I have an HTML file that will be portable to distribute to clients. It has an index of documents. I want a PDF or Word icon for each document but I don't want to repeat the base64 string 30 times if I can avoid it. How should I do this? Javascript is okay, but my goals are simplicity and portability.
627
Browsers can cache downloaded files. If the Base64 string is in a text (or JSON) file then it can be cached.
With the introduction of multiplexing that arrived with HTTP/2, web browsers have become incredibly efficient in delivering hundreds of files through a single connection. This works around most limits that the Base64 encoding solved and in fact means Base64 now does more bad than good.
Base64 is only useful for very small images. This is because when it comes to larger images, the encoded size of a picture in bytes will end up being much larger than JPEGs or PNG files.
It will however be larger than the source file. A ballpark figure is around 270 000 characters.
You can use a CSS variable.
In the <head> section of the page, name and define the variable and a class to use it:
:root {
--img-123: url(data:null;base64,iVBORw………); /* your image data here */
}
.img-123 {
background-blend-mode: normal;
background-clip: content-box;
background-position: 50% 50%;
background-color: rgba(0,0,0,0);
background-image:var(--img-123);
background-size: 100% 100%;
background-origin: content-box;
background-repeat: no-repeat;
}
In the <body> section of the page, use the image repeatedly via element style section or CSS classes. The SVG data creates a transparent image through which to see the content.
<img
class="img-123"
src="data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"><rect fill-opacity="0"/></svg>"
>
I observed this technique in the output of the open source Firefox / Chrome extension SingleFile. There might be ways to simplify the CSS and to avoid using SVG.
28
Try using CSS class
img.word-icon {
content: url(data:image/gif;base64,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);
width: 32px;
height: 32px;
}<html>
<body>
<img class="word-icon">foo
<img class="word-icon">bar
<img class="word-icon">
</body>
</html>The other answer using CSS gives the right idea, but it is not compatible with all browsers. The content property of the CSS is only allowed in the pseudo-elements ::before and ::after. The img tag with a class with a content property is empty. The browsers have no obligation to display it. Chrome displays it nevertheless (incorrectly).
To make this work for all browsers, use for example the ::before on an empty span:
span.word-icon::before {
content: url(data:image/gif;base64,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);
}<html>
<body>
<p><span class="word-icon"></span>Paragraph with icon.</p>
</body>
</html>You can also attach it directly to p::before.
22
create a script to insert it into the images. I purposely put the script code inline since you're sending a single HTML file:
<img alt="pdf"/>
<img alt="pdf"/>
<img alt="pdf"/>
<img alt="pdf"/>
<img alt="pdf"/>
<img alt="pdf"/>
<script>
var images = document.getElementsByTagName('img');
for (var i = 0; i < images.length; i++){
images[i].src = "data:image/png;base64,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";
}
</script>If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
