Remove nested requests

[suchow]

Consider the nested HTTP requests in the following snippet from questionnaire.js:

submit_responses = function() {
    if (lock===false) {
        lock=true;
        reqwest({
            url: "/question/" + participant_id,
            method: 'post',
            type: 'json',
            data: {
                question: "engagement",
                number: 1,
                response: $("#engagement").val()
            },
            success: function (resp) {
                reqwest({
                    url: "/question/" + participant_id,
                    method: 'post',
                    type: 'json',
                    data: {
                        question: "difficulty",
                        number: 2,
                        response: $("#difficulty").val()
                    },
                    success: function(resp) {
                        submit_assignment();
                    },
                    error: function (err) {
                        err_response = JSON.parse(err.response);
                        if (err_response.hasOwnProperty('html')) {
                            $('body').html(err_response.html);
                        }
                    }
                });
            },
            error: function (err) {
                console.log(err);
                err_response = JSON.parse(err.response);
                if (err_response.hasOwnProperty('html')) {
                    $('body').html(err_response.html);
                }
            }
        });
    }
};

Because the second HTTP request does not depend on the first, it is unnecessary to nest them in this way. It would be simpler to write a for loop over the questions and post them one by one.

This appears in several places elsewhere.

[suchow]

Okay, @thomasmorgan pointed out a problem with the above solution, which is that moving to the next page can interrupt the HTTP requests. Instead of a loop, we should write a recursive function that automatically extracts all the ids of the questions and recursively runs through the list, posting each response.

[DallingerBot]

This issue was moved to Dallinger/Dallinger#76