[SalesForce] Add custom field to attachment related list

You just need to Edit the task itself to see the Add Attachment button. It's only available in the task edit view.

crop1645, there's usually no great solution in situations like this. Definitely not ones supportable by Salesforce. So, with that said, maybe you can tweak Option 3 to work like this:

1. Extend your component as you described
2. Include the standard related list, and do render it
3. Hide the standard list using style="display:none"
4. Use JavaScript to "lift" the Salesforce-generated button and move it into your custom component

This is still prone to breaking, but you should have fewer cross-browser issues. Plus, you won't have to build the button; Salesforce will have built it for you.