Returns the URL from which the given element was loaded.
If the given element was never directly updated, but part of a larger fragment update, the closest known source of an ancestor element is returned.
In the HTML below, the element #one
was loaded from the URL /foo
:
<div id="one" up-source"/foo">
<div id="two">...</div>
</div>
We can now ask for the source of an element:
up.fragment.source('#two') // returns '/foo'
The URL from which the element was loaded.