Why does the second button not work, when ng-if is used?
I want to realize a button that is present only when the model value is set / not \"\"/ not nul
It doesn't work because ng-if is creating a new scope and interpreting your blub = 'yyyy' as defining a new local variable in the new scope. You can test this by putting the second button to:
<button ng-click="$parent.blub = 'yyyy'" ng-if="blub.length">Y</button>
However $parent is an ugly feature.
The button doesn't work because of the nested scope created by ng-if
. The blub
bound to the second button is not the same blub
that's bound to the first one.
You can use ng-show
instead of ng-if
, since it uses its parent's scope, but that's just avoiding the problem instead of solving it. Read about nested scopes so you can understand what actually happened.
Also, check this out: fiddle
Use ng-show Instead of ng-if
. That should work.
Fiddle
Try putting a magic dot on the variable
<input type="text" ng-model="bl.ub"/>
<br/>
<button ng-click="bl.ub = 'xxxx'">X</button>
<br/>
<button ng-click="bl.ub = 'yyyy'" ng-if="bl.ub.length">Y</button>
jsfiddle