Data saving exampleΒΆ

Code on the server (to receive the data). Save this as save_data.php

<?php
$json = file_get_contents('php://input');
$obj = json_decode($json, true);
$username = explode("/", dirname(__FILE__))[2];
$server_data = '/home/'.$username.'/server_data';
$path = $server_data."/".$obj["filename"];
if (substr(realpath(dirname($path)), 0, strlen($server_data))!=$server_data) {
    error_log("attempt to write to bad path: ".$path);
} else {
    file_put_contents($path, $obj["filedata"], FILE_APPEND);
}
?>

The experiment (which sends the data).

<html>
    <head>
        <title>datasaving</title>
        <script src="https://unpkg.com/jspsych@8.0.2"></script>
        <script src="https://unpkg.com/@jspsych/plugin-image-keyboard-response@2.0.0"></script>
        <script src="experiment.js"></script>
        <link href="https://unpkg.com/jspsych@8.0.2/css/jspsych.css" rel="stylesheet" type="text/css" />

        </head>
    <body></body>
</html>

var jsPsych = initJsPsych({
    on_finish: function() {
        var experiment_data = jsPsych.data.get();
        return save_data("test.csv", experiment_data.csv());
    }
});

var factors = {
    image: ['Dog1.jpg', 'Dog2.jpg', 'Dog3.jpg'],
    duration: [400, 800, 1200]
};

var factorial_values = jsPsych.randomization.factorial(factors);

var trial = {
    type: jsPsychImageKeyboardResponse,
    prompt: '<p>Press a key!</p>',
    stimulus: jsPsych.timelineVariable('image'),
    trial_duration: jsPsych.timelineVariable('duration')
};

var trials_with_variables = {
    timeline: [trial],
    timeline_variables: factorial_values
};

async function fetch_with_retry(...args) {
    let count = 0;
    while(count < 3) {
        try {
            let response = await fetch(...args);
            if (response.status !== 200) {
                throw new Error("Didn't get 200 Success");
            }
            return response;
        } catch(error) {
            console.log(error);
        }
        count++;
        await new Promise(x => setTimeout(x, 250));
    }
    throw new Error("Too many retries");
}


async function save_data(name, data_in){
    var url = 'save_data.php';
    var data_to_send = {filename: name, filedata: data_in};
    await fetch_with_retry(url, {
        method: 'POST',
        body: JSON.stringify(data_to_send),
        headers: new Headers({
                'Content-Type': 'application/json'
        })
    });
}

jsPsych.run([trials_with_variables]);