如何以反应形式动态设置默认值？

Question

I am creating the table with the looping, and if the loop value matches with the particular character I want to set the Reactive Form default value of Repeat else I want to set the empty value in the Reactive Form. Following Is my code

typescript

rDefault:string = "";
create(){
    let form = this.fb.group({
    rp:[this.rDefault]});
    return form;
}

template

<tbody  *ngFor="let c of ch.vl; let i = index" [formGroupName]="i">
    <tr class="ui-widget-content ui-datatable">
        <td>
        {{rpm[ofs+i].label}}
        </td>
        <td>
            <p-dropdown formControlName="rp" [options]="rpm[ofs+i].label =='REPEAT'? compOpt : []" appendTo="body" [disabled]='rpm[ofs+i].label == "REPEAT"?false:true'></p-dropdown>  
        </td>
    </tr>
</tbody>

If {{rpm[ofs+i].label}} this value is equal to "Repeat" I want to set the default form values as "Repeat", else empty value. How can I achieve this?

Answer 1

Got the solution for my question but I don't know this is the correct way or not?

In the every loop I am calling the another method from [option] and setting the value in that method.

template file

    <td>
        <p-dropdown formControlName="rp" [options]="changeDefault(rpm[ofs+i].label)" appendTo="body" [disabled]='rpm[ofs+i].label == "REPEAT"?false:true'></p-dropdown>  
    </td>

Updated TS file

rDefault:string = "";

//this method will change value of rDefault
changeDefault(val){
    this.rDefault = val == "REPEAT" ? "REPEAT" : "";
    let rtnar = 'REPEAT'? this.compOpt : [];
    return rtnar;
}
//


create(){
    let form = this.fb.group({
    rp:[this.rDefault]});
    return form;
}