I'm creating a page template for a plone-based website. I've defined some variables using the template attribute language:
<tal:macro metal:define-macro="sample" tal:define="var python: here.getThisVar();">
Now I would like to use var in an extern javascript file, that I call by clicking a button inside my template. How can I transfer my variable, that I can work with it in my javascript file?
In your template define a javascript variable by writing it out using TAL like this:
<script type="text/javascript" tal:content="string:var MY_VAR=${view/myVar};"></script>
Now MY_VAR should be available in scope of your external js as long as you call it after the line above...
Another way: inject your variable into HTML using an HTML 5 data attribute::
<div id="myVar" tal:attributes="data-myVar python:here.getThisVar();">
Then read it using JAvaScript/jQuery::
$('#myVar').data('myVar');
jq('#myVar').attr('myVar');jq('#myVar').attr('data-myVar');There are a variety of ways to do it. All involve constructing Javascript code as if it's text, then returning the result for insertion into a page or rendering as a JS resource in the javascript registry.
If you'd like a robust example that includes provisions for message translatability and works with the JS resource registry, see the way Plone itself does it: https://github.com/plone/Products.CMFPlone/blob/4.2.7/Products/CMFPlone/browser/jsvariables.py
tal:content to define and set js variables, then adding static js code that uses those vars. I personally create a namespace (js object) for this stuff to avoid collisions: tal:content="string:var Plone.myVar = 'foo'"