Possible shared state on core elements.

[Ashpants]

The documentation provides some great guidelines when initializing objects and arrays for an element. It suggests to initialize them in a created callback instead of the prototype object. This should prevent a “shared state”.

I tried to find some good examples of how this is done in the core and paper elements on the polymer site, and discovered this is typically not the case. I only found a few set up this way.

core-component-page has a created callback that initializes objects and arrays.

A few examples of elements that don't implement this are:
paper-radio-button
core-submenu
core-drawer-panel

The core and paper elements should be updated to using a created callback to further clarify the importance of its use, and prevent a shared state.

[arthurevans]

What shared state are you seeing? paper-radio-button and core-drawer-panel both have publish and eventDelegates objects, which are special objects used by Polymer. But I'm not seeing properties on either of them that are initialized to objects or arrays.

Note that published is documented: http://www.polymer-project.org/docs/polymer/polymer.html#published-properties

The eventDelegates object is not documented yet. The bug is here: Polymer/old-docs-site#546

[arthurevans]

What shared state are you seeing? paper-radio-button and core-drawer-panel both have publish and eventDelegates objects, which are special objects used by Polymer. But I'm not seeing properties on either of them that are initialized to objects or arrays.

Note that published is documented: http://www.polymer-project.org/docs/polymer/polymer.html#published-properties

The eventDelegates object is not documented yet. The bug is here: Polymer/old-docs-site#546

[arthurevans]

What shared state are you seeing? paper-radio-button and core-drawer-panel both have publish and eventDelegates objects, which are special objects used by Polymer. But I'm not seeing properties on either of them that are initialized to objects or arrays.

Note that published is documented: http://www.polymer-project.org/docs/polymer/polymer.html#published-properties

The eventDelegates object is not documented yet. The bug is here: Polymer/old-docs-site#546

[Ashpants]

Thanks for the quick response, I do see now that the objects I was concerned about are part of the publish object. Thank you for clearing that up.

I haven't run into a specific shared state scenario in my development, but was trying to find some use case examples of how to use a created callback.

Thanks for pointing out the eventDelegates as well.