https://www.polymer-project.org/1.0/docs/devguide/local-dom#dom-distribution
In the above link under "Dom Distribution" it says:
To support composition of an element's light DOM with its local DOM, Polymer supports the
<content>element. ...
Just wondering if this is out of date? Does Polymer 1.0 use slots as described here?
https://developers.google.com/web/fundamentals/primers/shadowdom/?hl=en#composition_slot
It's definitely working in Polymer 1.0, even with Shadow DOM; I'm currently using it in my projects which use Polymer 1.6, but it may be outdated in Polymer 2.0 or a newer version.
@ebidel confirmed that they will add the slots to webcomponents.js, but currently nobody is assigned to it: https://github.com/webcomponents/webcomponentsjs/issues/430
UPDATE
In the Polymer 1.7 they introduced the <slot> element for preparing to upgrade to 2.0 wich should be released soon. The 2.0 will not have the <content> element because they switching to the CustomElement v1 spec. I recommend that if you are plan to use <content> element then switch it to slot so in the future you will able to just upgrade the polymer library without heavy migrating.
The slot is working a bit different, the slot does not have a selector:
<dom-module id="my-element">
<template>
<slot name="content"></slot>
</template>
<script>
Polymer({
is: 'my-element'
});
</script>
</dom-module>
<my-element>
<div slot="content">My Content</div>
</my-element>
