How to pass a parameter to html?

Question

I have a script that uses the file picker but I need to pass a specific parameter which is called userId and is kept as a global variable in the calling script.

Answer 1

This post provides the solution how to pass parameter to a templated html:

html = HtmlService.createTemplateFromFile('page2');
html.id = s1;

Then in page 2 use the the tag to print out the id value;