Data Model Example

question.model.js

'use strict';

export class MultipleChoiceAnswerModel{
    constructor(rawQuestion){
        this.questionIdentifier = rawQuestion.identifier;
        this.type = rawQuestion.question_type;
        this.multipleChoiceAllowed = typeof rawQuestion.multiple === "string" ? JSON.parse(rawQuestion.multiple) : rawQuestion.multiple;
        this.choices = Array.from(rawQuestion.choices);
        this.userAnswer = null;
    }
}

export class TextAnswerModel{
    constructor(rawQuestion){
        this.questionIdentifier = rawQuestion.identifier;
        this.type = rawQuestion.question_type;        
        this.multilineAllowed = rawQuestion.multiline;
        this.userAnswer = null;        
    }
}

const questionTypes = [
    {type :"multiple-choice", answerModel: MultipleChoiceAnswerModel},
    {type :"text", answerModel: TextAnswerModel}
];

export default class QuestionModel {
    constructor(rawQuestion){
        this.type = rawQuestion.question_type;
        this.identifier = rawQuestion.identifier;
        this.questionSentence = rawQuestion.headline;
        this.description = rawQuestion.description;
        this.required = rawQuestion.required;
        this.answer = this.createAnswerModel(rawQuestion);
    }

    createAnswerModel(question){
        let Model = (questionTypes.find( questionType => questionType.type === question.question_type)).answerModel;
        return new Model(question);
    }
}

//Answer Type Enumaration
//In case of changing any property of enumaration, freeze the object.
export const answerTypes = Object.freeze({
    MULTIPLE :"multiple-choice",
    TEXT :"text"
});

Remote_responsejson

 "questions": [
      {
        "question_type": "multiple-choice",
        "identifier": "ac9835eb-9efa-4cce-9e35-09987d32e6c8",
        "headline": "Multiple Choice Question Sentence 1",
        "description": null,
        "required": false,
        "multiple": true,
        "choices": [
          {
            "label": "Answer 1",
            "value": "Answer 1",
            "selected": false
          },
          {
            "label": "Answer 2",
            "value": "Answer 2",
            "selected": false
          },
          {
            "label": "Answer 3",
            "value": "Answer 4",
            "selected": false
          }
        ]
      },
      
       {
        "question_type": "multiple-choice",
        "identifier": "af711459-9c79-41b7-a6a1-9035f0bac263",
        "headline": "Yes No question Sentence 2",
        "description": null,
        "required": false,
        "multiple": false,
        "choices": [
          {
            "label": "Yes",
            "value": 1,
            "selected": false
          },
          {
            "label": "No",
            "value": 0,
            "selected": false
          }
        ]
      },
      {
        "question_type": "text",
        "identifier": "37e8ea44-5061-415a-8da3-d49ddb6ba020",
        "headline": "Text question sentence",
        "description": null,
        "required": false,
        "multiline": true
      },
			{
        "question_type": "text",
        "identifier": "3a98eb1a-9009-4dc8-9497-0c2c14281c9b",
        "headline": "Text question sentence",
        "description": null,
        "required": false,
        "multiline": false
      }
   ]

someController.js

this.questions = this.survey.questions.map(question => new QuestionModel(question));