calling success function in executeQueryAsync

Question

i have a term set of details which have students as one term where i have three terms computer, biology, commerce.Inside to each term i have data which are terms.

details
    students 
         computer
            john
            jane   
         biology
            larry
            jevin
         commerce
            sam
            derik   

what i need is i need an array as result

output:

var output = [
              {id:"qweqdsadas", name:"john", dept:"computer"},
              {id:"eqweqwer", name:"jane", dept:"computer"},
              {id:"qweqweqwe", name:"larry", dept:"biology"},
              {id:"cxasdasd", name:"jevin, dept:"biology"},
              {id:"treeyrth", name:"sam", dept:"commerce"},
              {id:"jkhkjhkhk", name:"derik", dept:"commerce"}
             ]

i am able to create the array see the below code

  const fetchDetails = () => {
  let context = initializeContextData[0];
  context.load(studentTerms[0]) // which holds all the terms from students 
                                // term
  context.executeQueryAsync(() => {
    for(let i=0;i<studentTerms[0].get_count();i++){
      let child = studentTerms[0].getItemAtIndex(i)
      let subChild= child.get_terms();
      context.load(subChild);
      context.executeQueryAsync(() => {
        for(let i=0;i<subChild.get_count();i++){
          let studentDetails = subChild.getItemAtIndex(i)
          output.push({
            id: studentDetails.get_id()._m_guidString$p$0,
            name: studentDetails.get_name(),
            dept: child.get_name()
          })
        }
      })
    }
  })
}

// success method

const success = () => alert("data successfully pushed into array")

after creating the array i need to call a success method , since i am running in for loop and executeQueryAsync is an asynchronus function, how can i call a success method once the entire data is pushed into array, i tried $.Deferred but it doesn't seem to properly work . i am a beginner to javascript.

thanks in advance !!

Answer 1

You should use Promise.all with Deffered, it'll wait until all request resolve.

Link to documentation.