Here's the thing. I use 'Highlight.js' (a javascript-based automatic syntax highlighter) to syntax-highlight code on my website. But it doesn't support line numbers or zebra-striping (for alternate lines of code).
My code block is wrapped in <pre><code> blocks like this:
<pre><code>
<script type="text/javascript">
// Say hello world until the user starts questioning
// the meaningfulness of their existence.
function helloWorld(world) {
for (var i = 42; --i >= 0;) {
alert('Hello ' + String(world));
}
}
</script>
<style>
p { color: pink }
b { color: blue }
u { color: "umber" }
</style>
</code></pre>
And the output looks like this:
Now I want to show line numbers for the code block dynamically using JavaScript. How do I do that? (Also, if possible, how do I show zebra-striping?)
Thanks.
PS: I don't know JavaScript, so please try to be as clear as possible. I will try my best to understand. Thanks.
Here's the thing. I use 'Highlight.js' (a javascript-based automatic syntax highlighter) to syntax-highlight code on my website. But it doesn't support line numbers or zebra-striping (for alternate lines of code).
My code block is wrapped in <pre><code> blocks like this:
<pre><code>
<script type="text/javascript">
// Say hello world until the user starts questioning
// the meaningfulness of their existence.
function helloWorld(world) {
for (var i = 42; --i >= 0;) {
alert('Hello ' + String(world));
}
}
</script>
<style>
p { color: pink }
b { color: blue }
u { color: "umber" }
</style>
</code></pre>
And the output looks like this:
Now I want to show line numbers for the code block dynamically using JavaScript. How do I do that? (Also, if possible, how do I show zebra-striping?)
Thanks.
PS: I don't know JavaScript, so please try to be as clear as possible. I will try my best to understand. Thanks.
Share Improve this question asked Mar 24, 2012 at 9:47 its_meits_me 11.4k25 gold badges87 silver badges135 bronze badges3 Answers
Reset to default 4You could use an alternate framework such as http://alexgorbatchev./SyntaxHighlighter/
Or take a look here and find something that suites. http://www.1stwebdesigner./css/16-free-javascript-code-syntax-highlighters-for-better-programming/
Adding a new answer to an old question.
I wanted to display line numbers in the left margin the way ace.js does.
My solution has some hacky details, but I wanted to share it anyway, because it turns out that absolute-positioned spans within relative-positioned spans work pretty well for this.
Encouraged by the above answers and this answer about relative positioning without taking up space, I used:
var line = 1;
code = code.replace(/^/gm, function() {
return '<span class="line-number-position">​<span class="line-number">' + line++ + '</span></span>';
});
The regular expression /^/gm "replaces" the beginning of each line with the span-within-span.
​ is a zero-width space, because apparently firefox seems to have trouble deciding whether to put a zero-height span at the top or the bottom of the character.
line-number-position and line-number are CSS classes like these:
.line-number-position {
position: relative;
top: 0;
}
.line-number {
position: absolute;
text-align: right;
right: 17px;
font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', 'Consolas', 'source-code-pro', monospace;
font-size: 12px;
}
Yes, there are some magic numbers in there to match ace formatting, but the point is to put a relative-positioned zero-sized span at the beginning of each line and use it as a reference point to add an absolute-positioned span out in the left margin.
Works on current Chrome, Safari, Firefox, and Opera.
The basic steps would be:
- Take the HTML inside the element.
- Split by newline characters (
\n). - For each string, add a number and a dot in front of it.
- Combine the strings again with newline characters.
- Set the string as the HTML of the element.
However, this would mess up the syntax highlighting of the syntax highlighter because it most likely won't recognize that the code has line numbers in front. So the syntax highlighter needs to provide the functionality of line numbers for you.