Polymer: access properties of parent or other elements
<p>How do I access properties of parent or other elements in Polymer?</p>

<p>For example my top-most element is "my-app".</p>

<p>Now I am in an element called "my-element-1", how would I access/reference any properties from "my-app" using Javascript?</p>

<p>Further, if I am in "my-element-2", would I be able to access/reference properties of "my-element-1"?</p>

<p>EDIT: There are many reasons why I want to do this, and I certainly believe there are better ways than having to do this. But, I do not know the ways.</p>

<p>1: The first use case that comes to mind is that I use "iron-pages", which is located in a parent element. Each "page" is therefore a child of that parent.</p>

<p>The parent definitely knows which "page" is "selected" because the "iron-pages" is a property of the parent.</p>

<p>However, each "page" does not know if it is selected or no longer selected because the "selected" attribute is only known to the parent.</p>

<p>In this use case, I just want to be able to know from within the "page" whether it is still selected or not.</p>

<p>2: The second use case is probably a general design pattern. I want to maintain a set of GLOBAL properties, which can then be accessed anywhere from within the Polymer app. My assumption is that it should be store within "my-app" as the root element. </p>