>>Don't get it. 'disable-action="disableClearMessage" ' is setting the value to a string. How does it get to a bool ?
>>
>>
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>>>However, the button is not disabled and I can click on it just fine and the click event works. It may be a minor problem since the only reason I want to disable the button if there is nothing to clear (the message is empty anyway).
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>disableClearMessage is a variable I define in the controller's code. So, I set it to true or false in the code.

You mean it is in the controller scope? As before you are assigning a string - you need to reference it in the scope:

disable-action="{{disableClearMessage}}"

It's exactly the same problem as you describe below.....

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>In the directive it was originally
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>ng-disabled = " disableAction"
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>and it didn't work (e.g. it was disableAction in the resulting HTML).
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>So, I changed last line of the directive to read as
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>ng-disabled = "{{ disableAction}} "
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>so now it probably evaluates the value of the disableClearMessage and sets it to true, so the ng-disabled = "true" now.
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>The strange thing is that it does work correctly in the New mode, but in the Edit mode the exactly same HTML code doesn't work.