Markdown Interpolation

Find and replace the content between markdown comments.

This is intended for use in Node.js because it has some file operation logic for convenience.

Writing

Let's say you have a file called README.md with this content.

My name is Bob.

You can make the name "Bob" dynamic.

Let's call our variable NAME by using the prefix <!-- NAME --> and suffix <!-- END NAME -->.

My name is <!-- NAME -->Bob<!-- END NAME -->

Write by file name

Now write some javascript to replace the content Bob with John.

import { mdIFileWrite } from 'markdown-interpolation';

mdIFileWrite('README.md', {
    NAME: 'John'
});

This will result in the following file.

My name is <!-- NAME -->John<!-- END NAME -->

When rendered in markdown it will appear as follows.

My name is John

Write by regex match on file names

You can use regular expressions to match multiple files in a single call.

For example match all files that end with .md.

import { mdIFileWrite } from 'markdown-interpolation';

mdIFileWrite(/.*\.md/i, {
    NAME: 'John'
});

Reading

You can read all the markdown variables back.

Let's continue using the example from the previous section.

My name is <!-- NAME -->John<!-- END NAME -->

Read content of all variables

Read all the variables from a file.

import { mdIReadEntries } from 'markdown-interpolation';

const results = mdIReadEntries('TEST.md');
console.log(results);

The output will be a JSON array of objects describing each variable.

[{
    "key": "NAME",
    "value": "John"
}]

Regex

This entire thing is powered by regex. Below is the expression.

/(?<=<!-- ?${key} ?-->)(.*?)(?=<!-- ?END ${key} ?-->)/gs