Implementing Moodle's Privacy API in a Moodle Plugin - Part 4

Continuing the series on implementing Moodle's Privacy API in my questionnaire plugin, I will add code to handle all of the questionnaire data. I did my smaller test set, but now I need to get a fully working implementation.

To start with, I need to add all of the potential response data to my privacy data provider. For questionnaire, this includes multiple question and response tables. For the export, I also need to design an appropriate output structure. This post will work on fulfilling these functions.

I have a couple of options for an output structure. I can create one JSON structure with all of the responses, questions and answers, like this:

{
    "name": "Test Questionnaire",
    "intro": "A wonderful description of the questionnaire.",
    "responses": [
        {
            "complete": "Yes",
            "lastsaved": "Friday, 18 November 2016, 8:14 pm",
            "questions" : [
                {
                    "questionname": "Q1. Car ownership",
                    "questiontext": "Do you own a car?",
                    "answers": [
                        "No"
                    ]
                },
                {
                    "questionname": "Q2. Characters",
                    "questiontext": "Enter no more than 10 characters.",
                    "answers": [
                        "123456"
                    ]
                },
                {
                    "questionname": "Q3. Numbers",
                    "questiontext": "Check all that apply",
                    "answers": [
                        "1,3,5,Another number: 7"
                    ]
                },
                {
                    "questionname": "Q4. Rate course",
                    "questiontext": "Rate these",
                    "answers": [
                        "Formatting your course: Very easy to use",
                        "Laying out your course: Easy to use"
                    ]
                }
            ]
        }
    ]
}

Or I could use subcontexts, and create a directory structure. Something like this:

In this case, each response by the user would have its own directory, with a separate subdirectory for each question and its specific response. This would be done using subcontexts. I feel the first option is really the best choice for what I need. The second one seems like overkill.

Building the directory structure is done in the forum module. I'm not completely sure how it works, but if you walk through the forum's provider file, you can see that it is built through arrays, and exported through nested calls to export_data.

In any case, building a JSON structure like the one I planned above, is not too difficult. I already have a function in questionnaire that returns a structured data set that I use when sending responses via email or other notification methods. It isn't exactly what I need, but is close enough. So I'll modify it and make sure it still works for the code that uses it currently. The modified code is here, and I create another quick function to use in the privacy provider. The rewrite of my export function that provides all appropriate response data now looks like this.

The last thing I require is the full deletion functions. I do have some library functions that delete response data, but they also log events. The core plugins all seem to provide direct database deletions rather than using their deletion library functions. So, I'll do the same, creating one function that does most of the deletion work so that the two privacy API functions don't have to duplicate that code. The end result is here.

I have tested all of this code with the test code Moodle provided. It all seemed to work fine. I'll see if I can create some automated tests into the module's testing code as well, and do more testing before I release this.

If you have any questions about this work, please ask here or in the forums on Moodle.org.