Obsidian Regex Mark is a plugin for Obsidian that allows you to add custom CSS classes to text based on regular expressions.

Add a regular expression and a CSS class to the plugin settings. The plugin will then add the CSS class to any text that matches the regular expression.

And data-contents will be added to the span tag

The following regular expression will add the CSS class comment to any text that matches the regular expression.

regex: //.*$
class: comment

And the following text

This is a normal line of text. //This is a comment.

will be converted to

<p>This is a normal line of text. <span class="comment">//This is a comment.</span></p>

It is also possible to create "custom" markdown tags using the {{open:regex}} and {{close:regex}} syntax. You need to toggle the option hide to enable it.

The plugin will mimic the behavior of Obsidian with transforming:

__text__

to

<span>
	<span class="cm-hide">__</span>
	<span class="cm-underline">text</span>
	<span class="cm-hide">__</span>
</span>

The css will after hide the .cm-hide class, unless you select it (only in livePreview for the selection).

Selecting the text will show everything, like with other markup.

• Underline : {{open:__}}(.*){{close:__}}
• SuperScript : {{open:\^}}(.) (Note: It works for "one" character only here, but you can use ^x^ syntax if you want to use for more text: {{open:\^}}(.*){{close:\^}})
• SubScript : {{open:_}}([a-zA-Z\d]\b)) (As before, it works for only one element)

The css for the above example is:

.superscript {
	vertical-align: super;
	font-size: 90%;
}
.subscript {
	vertical-align: sub;
	font-size: 90%;
}

You can then use the CSS class to style the text in your CSS snippet or any other usages.

If your Obsidian refuse to open file and you get this error in the console:

RangeError: Decorations that replace line breaks may not be specified via plugins

That's mean that one of your regex doesn't work inside Obsidian. You need to check every regex you have added to find the one that cause the issue and delete it, and reload Obsidian to make it work again.

• rien7: Original work