How to make your designs in the visual editor?

Question

JavaScript

Hello!
There is some html code in which some constructs are inserted. For example:

<p>123</p>
[myConstruction?someparam=value]
<p>123</p>

It is necessary to visualize these structures in the editor, make a convenient setting of parameters. Based on which editor is it better to implement this and how? How is this even called? Thank you.