What is the best way to remove all selected items in a dropdown menu?

My issue pertains to Angular and Typescript. I am facing a challenging problem with a dropdown menu that has 3 items. The unique aspect is that I am not utilizing the standard select HTML tag; instead, I am using my company's custom toolkit, which serves as a wrapper for primeng components with our specific branding elements. This toolkit is known as PLK toolkit. Unfortunately, there is a bug in their code where the previously selected item is not being cleared properly. Below is an example of their dropdown code:

Note: In the following code snippet, plk-dropdown serves as a replacement for the select tag, while plk-option replaces option.

<plk-dropdown [(ngModel)]="fruit" name="fruit">
    <plk-option [value]="'apple'">Apple</plk-option>
    <plk-option [value]="'pear'">Pear</plk-option>
    <plk-option [value]="'melon'">Melon</plk-option>
</plk-dropdown>

Initially, on clicking, it works fine. However, subsequent clicks result in multiple selections. Upon examining their code:

dropdown.js

DropDownComponent.prototype.writeValue = function (value) {
    if (this.options) {
        this.selectOptionByValue(value);
    }
};

I managed to resolve the bug by adding one line of code:

DropDownComponent.prototype.writeValue = function (value) {
  if (this.options) {
      this.clearSelectedOptions(); // THIS I ADDED
      this.selectOptionByValue(value);
  }
};

The component is now functioning correctly. However, I am unable to modify their JavaScript file, both due to restrictions and the risk of reappearing bugs after repository updates.

Is there a way to address this issue purely through TypeScript code without introducing jQuery? I attempted the solution mentioned here, but to no avail.

Your assistance would be greatly appreciated as I am currently stuck. Thank you.

Answer №1

When using a dropdown without any values selected, I employ a null option. This is particularly relevant when working with primeng, as it allows me to set the first option as selected even if the value does not match the ngModel property. I have created a demonstration to illustrate this concept. By doing so, users have the ability to undo their selection in case it was made in error.

<plk-dropdown [(ngModel)]="fruit" name="fruit">
    <plk-option [value]="null">Unselected</plk-option>
    <plk-option [value]="'apple'">Apple</plk-option>
    <plk-option [value]="'pear'">Pear</plk-option>
    <plk-option [value]="'melon'">Melon</plk-option>
</plk-dropdown>

Check out the demo 🚀

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