Ensure script remains installed after updates

Question

I have some script I want to add to my wordpress page (which contains Latex math, for which I use MathJax), so what I used to do is edit header.php in my themes, which is OK, except that every time I do an update, I have to edit that again and again... which is annoying and some times I forget to do that.

Is there anyway I could set that script permanently even after an update?

Answer 1

The solution is to create your own plug-in, which turns our to be much simpler than anyone thinks.

1- Pick a name for your plugin, I'll call it MyPlugin

2- Open a folder in your /wp-content/plugins/MyPlugin

3- Open a file inside the latter folder and call it MyPlugin.php

4- Input the following in that file:

<?php
/*
Plugin Name: MyPlugin
*/
function add_my_header() {
    echo '<script type="text/x-mathjax-config">';
    echo 'MathJax.Hub.Config({';
    echo 'tex2jax: {inlineMath: [[\'$\',\'$\']]}';
    echo '});';
    echo '</script>';
    echo '<script type="text/javascript"';
    echo '  src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_SVG">';
    echo '</script>';
}
add_action( 'get_header', 'add_my_header' );
?>

You may change the script as you want.

5- Enable the plugin.

6- You're done! Give me a thumbs-up, and have fun :)