How To Assign Data From Service To Json?

I am making angular 6 application, where i am making a angular dynamic form in which the data comes as dynamic from JSON. JSON: jsonData: any = [ { 'elementType': 'text

Solution 1:

you must ask yourself about what data you receive and what data do you need. In general you can has,e.g.

getOptions():Observable<any[]>
{
   //of, create an observable
   return of(
     [{key:"option1",data:["option1_1","option_1_2"]},
      {key:"option2",data:["option2_1","option_2_2","option_2_3]},..
     ])
}

getModel():Observable<any[]>
{ 
  return of(
            [{key:"option1",...},
             {key:"option2",..}
     ])
}

You must use switchMap to received the fullModel. switchmap make that you don't receive the first call else the inner one. is a way to not encatenate subscribe

getFullMode():Observable<any[]>
{
     returngetOptions().pipe(switchMap(
        opts=>{
           returngetModel().pipe(map(mod=>{
             //..here transform "mod" using the values of opts//e.g.let option=opts.find(p=>p.key=mod.key);
             mod.options=option.data
           }))
        })
     )
}

Well, you case is easer because only has an "option" and a unique "option", anf json is fixed.

getFullJson(url,token) 
{
    this.service.get(url,token).pipe(map(opt=>{
      //we don't want return opt, else this.jsonData transformed.let element=this.jsonData.find(e=>e.elementType=='dropdown');
      if (element)
         element.option=res.datareturnthis.jsonData
    }))
  }).subscribe(res=>console.log(res));

If your json comes from an observable, not use map, use switchmap. SwitchMap, wait the outer call end to make the second

getFullJson(url,token) {
    this.service.get(url,token).pipe(switchMap(opt=>{
    //we don't want return opt, else this.jsonData transformed.//to transform data use pipe(map)returnthis.service.getJsonData(pipe(map(jsonData=>{
         let element=jsonData.find(e=>e.elementType=='dropdown');
         if (element)
           element.option=res.datareturnthis.jsonData
    }))
  }).subscribe(res=>console.log(res));