In my dropdown list of objects, I have a person object with properties like id, firstName, and lastName.
<select formControlName="person">
<option *ngFor='let person of persons" [ngValue]="person">{{person.firstName+' '+person.lastName}}</option>
</select>
Suppose I want to determine if a specific person object is already in the dropdown list. If it exists, I would like that person object to be automatically selected as the default value in the dropdown list.
To set a default value in your form, you can utilize the formControl feature. Depending on whether the value is available during component initialization, you can either assign it when constructing the form or use patchValue after receiving the value. If you have the data when building the form:
ngOnInit() {
this.myForm = this._fb.group({
person: [this.persons[1]]
});
}
In this case, we typically avoid using ngValue as it binds the entire object. However, feel free to use it if necessary for your particular situation.
Alternative method to approach dropdown default value setting without using ngModel involves utilizing the index (i) within each iteration of *ngFor directive. By applying the 'selected' property on the option element, you can specify the index (i) corresponding to the desired default option. In this scenario, the 2nd option is set as the default selection. The index represents the position of each option within an array. Below is a slightly modified example showcasing this technique:
@Component({ selector: 'my-app', template: ` {{option.name}}
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