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Re: Is this how you can use bindings?
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Re: Is this how you can use bindings?


  • Subject: Re: Is this how you can use bindings?
  • From: Ron Lue-Sang <email@hidden>
  • Date: Tue, 12 Aug 2008 23:56:13 -0700

The way to think about this is, you bind the value of the text field to a controller (or model) object that owns the value. Then, bind the enabled binding of the button to the same property of of the same controller and use a valuetransformer to check whether the value is nil.

So your setup should look like:
- TextField value binding bound to yourObject with keypath yourStringProperty
- button enabled binding bound to yourObject with keypath yourStringProperty with value transformer NSIsNotNil


You may want to turn on "continuously updates value" for the textfiled's value binding.This way as soon as the user starts typing, the enabled state of the button will get toggled.

Note that part of why this works with the value transformer is because the textfield value binding sets nil as the value when the textfield is emptied.

---------------------
RONZILLA

On Aug 12, 2008, at 11:21 PM, Chris Idou <email@hidden> wrote:

I want a button to be enabled when myTextField is not empty.

Can have an outlet in my controller called myTextField, and then set the "Enabled" binding on the button to point to myTextField.stringValue.length, then can I write a transformer called GreaterThanZero to return boolean if the input is greater than zero?

Is that a valid way to go about this problem? It doesn't seem to be working for me. I wrote a myTextField accessor to see what is happening and it doesn't even seem to get called.






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