Listbox should not be empty

Listbox should not be empty

Posted by: nivishapanwar on 22 February 2021, 5:12 pm EST

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  nivishapanwar

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  Posted 22 February 2021, 5:12 pm EST

  Hello,
  
  I am using a wijmo listbox . In that I am using add, remove , update functions.
  
  How can i restrict the listbox to be not empty, means there should be always a record present in listbox.
  
  removeRecord() {
  
  let lb = this.ListData.collectionView;
  
  lb.items.splice(this.ListData.selectedIndex, 1);
  
  lb.refresh();
  
  this.ListData.selectedIndex = -1;
  
  this.fullname = “”;
  
  this.saveListBoxData();
  
  }
  
  displayListBoxValueInTextField(listBox) {
  
  this.fullname = listBox.selectedValue;
  
  }
  
  Thank you.

  Regards,
  
  Nivisha Panwar

• 

  ashwin.saxena

  

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  Posted 22 February 2021, 9:51 pm EST

  Hi Nivisha,

  You can add a check initially whether at least one item is present or not:

  removeRecord() {
  	let lb = this.ListData.collectionView;
  	if(lb.totalItemCount <= 1) {
  		return;
  	}
  	.....
  }
  

  Regards,
  
  Ashwin

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  nivishapanwar

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  Posted 28 February 2021, 10:31 pm EST

  Hi Ashwin,
  
  I tried using this, but it gave an error that totalitemcount property doesn’t exist in collection view.
  
  Then I tried with ._src.length but still got the same error.Can you suggest something else?
  
  Thank you.

  Regards,
  
  Nivisha

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  ashwin.saxena

  

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  Posted 1 March 2021, 10:55 pm EST

  Hi Nivisha,

  This type of error is not thrown by JS. If the totalItemCount property is not present in CollectionView, then it will return undefined and will not produce this error. So, please make sure that this.ListData.collectionView is actually an instance of CollectionView.
  
  You can also use items.length or sourceCollection.length property.

  ~regards

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  nivishapanwar

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  Posted 1 March 2021, 11:03 pm EST

  Hi Ashwin,

  Thanks for the help, sourceCollection.length property worked.

  Regards,
  
  Nivisha