jsPsych/plugins/jspsych-single-stim.js
2014-09-09 08:36:39 -04:00

145 lines
5.4 KiB
JavaScript

/**
* jspsych-single-stim
* Josh de Leeuw
*
* plugin for displaying a stimulus and getting a keyboard response
*
* documentation: https://github.com/jodeleeuw/jsPsych/wiki/jspsych-single-stim
*
**/
(function($) {
jsPsych["single-stim"] = (function() {
var plugin = {};
plugin.create = function(params) {
params = jsPsych.pluginAPI.enforceArray(params, ['stimuli', 'choices', 'data']);
var trials = new Array(params.stimuli.length);
for (var i = 0; i < trials.length; i++) {
trials[i] = {};
trials[i].type = "single-stim";
trials[i].a_path = params.stimuli[i];
trials[i].choices = params.choices;
// option to show image for fixed time interval, ignoring key responses
// true = image will keep displaying after response
// false = trial will immediately advance when response is recorded
trials[i].continue_after_response = (typeof params.continue_after_response === 'undefined') ? true : params.continue_after_response;
// timing parameters
trials[i].timing_stim = params.timing_stim || -1; // if -1, then show indefinitely
trials[i].timing_response = params.timing_response || -1; // if -1, then wait for response forever
trials[i].timing_post_trial = (typeof params.timing_post_trial === 'undefined') ? 1000 : params.timing_post_trial;
// optional parameters
trials[i].is_html = (typeof params.is_html === 'undefined') ? false : params.is_html;
trials[i].prompt = (typeof params.prompt === 'undefined') ? "" : params.prompt;
trials[i].data = (typeof params.data === 'undefined') ? {} : params.data[i];
}
return trials;
};
plugin.trial = function(display_element, block, trial, part) {
// if any trial variables are functions
// this evaluates the function and replaces
// it with the output of the function
trial = jsPsych.pluginAPI.normalizeTrialVariables(trial);
// this array holds handlers from setTimeout calls
// that need to be cleared if the trial ends early
var setTimeoutHandlers = [];
// display stimulus
if (!trial.is_html) {
display_element.append($('<img>', {
src: trial.a_path,
id: 'jspsych-single-stim-stimulus'
}));
} else {
display_element.append($('<div>', {
html: trial.a_path,
id: 'jspsych-single-stim-stimulus'
}));
}
//show prompt if there is one
if (trial.prompt !== "") {
display_element.append(trial.prompt);
}
// function to end trial when it is time
var end_trial = function(info) {
// kill any remaining setTimeout handlers
for(var i = 0; i < setTimeoutHandlers.length; i++){
clearTimeout(setTimeoutHandlers[i]);
}
// kill keyboard listeners
jsPsych.pluginAPI.cancelKeyboardResponse(keyboardListener);
// gather the data to store for the trial
var trial_data = {
"rt": info.rt,
"stimulus": trial.a_path,
"key_press": info.key
};
block.writeData($.extend({}, trial_data, trial.data));
// clear the display
display_element.html('');
// move on to the next trial
if (trial.timing_post_trial > 0) {
setTimeout(function() {
block.next();
}, trial.timing_post_trial);
} else {
block.next();
}
};
// function to handle responses by the subject
var after_response = function(info) {
// after a valid response, the stimulus will have the CSS class 'responded'
// which can be used to provide visual feedback that a response was recorded
$("#jspsych-single-stim-stimulus").addClass('responded');
if (trial.continue_after_response) {
// response triggers the next trial in this case.
// if hide_image_after_response is true, then next
// trial should be triggered by timeout function below.
end_trial(info);
}
};
// start the response listener
var keyboardListener = jsPsych.pluginAPI.getKeyboardResponse(after_response, trial.choices);
// hide image if timing is set
if (trial.timing_stim > 0) {
var t1 = setTimeout(function() {
$('#jspsych-single-stim-stimulus').css('visibility', 'hidden');
}, trial.timing_stim);
setTimeoutHandlers.push(t1);
}
// end trial if time limit is set
if (trial.timing_response > 0) {
var t2 = setTimeout(function() {
end_trial({rt: -1, key: -1});
}, trial.timing_response);
setTimeoutHandlers.push(t2);
}
};
return plugin;
})();
})(jQuery);