CODEWITHSUNDEEP
sapui5
Sravan Kumar
Sravan Kumar

Reputation: 3

How to set visible property as false if model does not yet defined? (SAPUI5)

my model "categories" is defined on the second view controller and set as a global model. but in the first view, I have a button and set its visible condition like below

<Button text="Click Me" visible="{=${categories>/}.length > 0}" />

the button should only be visible when the categories model has data.

but since I have not yet navigated to the second view and my model is not yet defined. the expression binding is not working for the button in the first view. how do set the button visible as false if the model is not defined and has no data? only using XML, not with javascript.

/}.length > 0}" />

Upvotes: 0

Views: 861

Answers (1)

depth1
depth1

Reputation: 145

According the Expression Binding Documentation, you can use Function call and Binary logical operator.
With that, you can for example do this expression binding:

{= Array.isArray(${model}) && ${model}.length > 0 }
  1. Check model exists and is an Array
  2. And
  3. Check model size > 0

With that if model is not existent or is not an array or is an empty array the answer is false otherwise true.

With you code it would give :

<Button text="Click Me" visible="{= Array.isArray(${categories>/}) &amp;&amp; ${categories>/}.length > 0 }" />

& character from binary operator must be escaped in XML with &amp;
XML syntax escaping rules

Upvotes: 1

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