Parse single quiz MCQ

parser.js

class McqParser {

    getQuestionNode(doc) {
        return doc.querySelector('.question_box>h3>p');
    }

    getOption(labelEl) {
        return new McqChoice(
            labelEl.innerHTML,
            labelEl.title
        );
    }

    getOptions(doc) {
        var options = [];
        var labels = doc.querySelectorAll('.question_box>label');
        labels.forEach((labelEl) => {
            options.push(this.getOption(labelEl));
        })

        return options;
    }

    parse(doc) {
        return new MCQ(
            this.getQuestionNode(doc),
            this.getOptions(doc)
        )
    }
}

class MCQ {
    constructor(text, choices, ans) {
        this.text = text;
        this.choices = choices;
        this.ans = ans;
    }

    static loadFromObj(obj) {
        var text;
        if(typeof obj.text == 'string'){
            text = document.createElement('p');
            text.innerText = text;
        }
        else 
            text = obj.text;

        return new MCQ(text, obj.choices, obj.ans);
    }

    getJSON() {
        var options = this.choices.map((opt) => opt.getJSON())
        return {
            text: this.text.innerText.trim(),
            choices: options,
            ans: this.ans
        }
    }

    existsIn(qDict) {
        for (var qId in qDict) {
            if (qDict[qId].text == this.text.innerText.trim())
                return MCQ.loadFromObj(qDict[qId]);
        }
    }

    mark(id) {
        document.querySelector(`[value='${id}']`).click();
    }

    getHash() {
        return this.text.innerText.trim().hashCode();
    }

    setAns(id) {
        this.ans = id;
    }

    updateAnsFromText(text){
        for(var choice of this.choices){
            if(choice.text == text){
                this.ans = choice.id;
                return;
            }
        }
    }
}

class McqChoice {
    constructor(text, id) {
        this.text = text;
        this.id = id;
    }

    getJSON() {
        return {
            text: this.text.trim(),
            id: this.id
        }
    }
}