A custom object's setup page has a section "Buttons, Links, and Actions". I've created buttons and links in the past, but do not remember the "action" option being there.
Can anyone explain what "action" is for and compare it with what "button" offers? The salesforce help doesn't seem to have documented "action" yet.
You need to use the window open properties button on the button detail page
This will allow you to set all properties for your popup
We can now query those 01I object ids and 00N field ids directly without Tooling API or callouts.
List<EntityParticle> entities = [
SELECT DurableId
FROM EntityParticle
WHERE EntityDefinition.QualifiedApiName = 'MyCustom__c'
];
This will return:
DurableId
01I7F000001fbTC.LastViewedDate
01I7F000001fbTC.LastReferencedDate
01I7F000001fbTC.00N7F00000HnXIU
01I7F000001fbTC.00N7F00000HnXIW
...
Much easier than the historical solution - and no Session ID involved or API privilege issues.
Best Answer
These relate to a new feature to extend Chatter in Summer'13, allowing you to add your own actions for users to select when responding to comments left directly in the Chatter feed.
I've seen them called Multi Dimensional Publisher (MDP) Actions or Publisher Actions or Chatter Actions. The branding is I think still settling. It is odd the standard links are broken, its worth submitting a case to them to fix this. By searching for Publisher Actions in the main help I found this page that should lead you to the main topics you need. Also the Summer'13 training docs have a good video here. You can also find an excellent blog on the topic here from Daniel Hoechst (Salesforce MVP).
For a more advanced discussion on using Visualforce pages with these button see here.