Accessing function of Ionic app running inside an iFrame

Hi guys,

Here i am again with a very specific question.

I’m using a web page and an iFrame to run my application pretty much like in the Ionic documentation.
What i’m trying to do is being able to fire a function that is inside my application from the webpage that is running the iFrame. Any way i could do that?

The final goal being that my client can see a ‘bare’ version of my app (without business logic) and can select colors to personnalise the app to his business. (hence firing a function that would set colors attributes in my running app).

The set up is very basic and mostly copy/paste from inonic doc :

    <script src="script.js"></script>
    <div id="phone-case">
            <iframe id='targetFrame' src=/pathToRunningApp"></iframe>

        <input type="button" value="click" onclick="test()" />
 function test() {