First, I would like to clarify that this is a proposal for API change and not a bug report. AFAIK the existing API is working as advertised.
Currently, attribute values specified in hostAttributes will automatically override user-specified values for those attributes. I propose that this should be changed, so that attributes specified in hostAttributes will respect and defer to user-specified values.
One of the more tempting uses of hostAttributes is to set default ARIA attributes like role, and / or related ARIA states and properties. However, hostAttributes is a bad choice for this because you generally want to respect user-provided values for those same attributes.
For anecdotal evidence that the proposed behavior is preferable to the current behavior, please refer to the discussion here: PolymerElements/paper-toggle-button#1 (comment)
First, I would like to clarify that this is a proposal for API change and not a bug report. AFAIK the existing API is working as advertised.
Currently, attribute values specified in
hostAttributeswill automatically override user-specified values for those attributes. I propose that this should be changed, so that attributes specified inhostAttributeswill respect and defer to user-specified values.One of the more tempting uses of
hostAttributesis to set default ARIA attributes likerole, and / or related ARIA states and properties. However,hostAttributesis a bad choice for this because you generally want to respect user-provided values for those same attributes.For anecdotal evidence that the proposed behavior is preferable to the current behavior, please refer to the discussion here: PolymerElements/paper-toggle-button#1 (comment)