Dropdown: "0" Value in optionValue, causes Label to be replaced by Placeholder

[eduardheller89]

Describe the bug

When the value of the dropdown is 0, the placeholder value is still shown in the input.

This is the line causing the issue

return this.modelValue() ? this.getOptionLabel(this.selectedOption) : this.placeholder || 'p-emptylabel';

this Line in component.ts causes '0' to be accepted as False. You should check for null or undefined.

Thanks

Environment

Win10/chrome

Reproducer

No response

Angular version

17.1.2

PrimeNG version

17.5.0

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

18.19.0

Browser(s)

Chrome 121

Steps to reproduce the behavior

1. Set Dropdown to a value in optionValue to 0.
2. Set Dropdown placeholder
3. Change the value of the dropdown in the ui to the corresponding value with Value 0
4. Placeholder still remains in the input

Expected behavior

The optionLabel should show the Label of the optionValue with Value 0

[Cr3aHal0]

Hi,

Not sure if this is by design or if more options should be available other than '0' such as true, false or empty string. If empty/null comparison is enough, the linked PR should be okay

[rosenthalj]

This issue is the result of a condition that I did not consider when the code was changed for pull request #14665.

I believe that 2 sets of changes need to be made to fix this issue.

Please see the annotated screenshot of pull request #14665 listed below

[Cr3aHal0]

Hi rosenthalj,

I'll be investigating your suggestion, I did not encountered any incorrect behaviour while testing the change but i'll retry :)

[rosenthalj]

Cr3aHal0,

When testing I would recommend that you try the following "filtering" cases:

1. A test case similar to the last video in pull request Fix #14596 - fixes p-dropdown logic for selectedOption and label #14665 comments.
   --- set options 0, 1, 2
   --- select 0
   --- enter 1 in the filter
2. A test case that enters a value that doesn't match any option
   --- set options 0, 1, 2
   --- select 0
   --- enter "A" in the filter

[cetincakiroglu]

Fixed in #14719

[eduardheller89]

Thank you for being fast with the issue. Thats great