jsPsych/plugins/jspsych-text.js
Josh de Leeuw 9651f983a2 1/21/2013
2013-01-21 18:45:03 -05:00

107 lines
5.1 KiB
JavaScript

/* jspsych-text.js
* Josh de Leeuw
*
* This plugin displays text (including HTML formatted strings) during the experiment.
* Use it to show instructions, provide performance feedback, etc...
*
* No data is currently collected with this plugin. Do not use it for situations in which
* data collection is important.
*
* Parameters:
* type: "text"
* text: an array of strings. Each element in the array will be displayed on a separate screen.
* cont_key: the keycode of the key the user should press to advance to the next screen. Default is '13' which is ENTER.
* timing: an array with a single element representing the time in milliseconds to delay on a blank screen after the continue key is pressed. Default is no delay.
* variables: see variables section below.
*
* Optional Variables: If you want to display dynamic information that is updated at the moment the text is rendered on the screen,
* such calculating an accuracy score to tell a subject how many trials they got right, you can use the optional variables parameter.
* The variables are specified as an array of arrays. The outer level array indexes for which block of text you are showing, and the
* outer array should have the same length as the text array. Each element of the outer level array is also an array, with one element
* for each variable that you are specifying. Variables are specified as functions which return the string that you want to display.
* To indicate where a variable should be placed in the text, use the special string "%v" in the text. This will be replaced by the
* return value of the function that is in the variables array. Each "%v" string will be replaced in the order that they appear in the
* text, and only one replacement will be made per function call. Therefore, you should have the same number of "%v" strings as you have
* elements in the inner arrays of the "variables" array.
*
* Example:
* var goodbye_func = function(){return "goodbye";}
* var hello_func = function(){return "hello";}
* "text": ["%v, %v.", "I don't know why you say %v, I say %v."]
* "variables":[[hello_func, hello_func],[goodbye_func, hello_func]]
*
* When the above parameters are loaded into the text plugin, the first screen would show
* "hello, hello." and the second screen would show "I don't know why you say goodbye, I say hello."
*
*/
(function( $ ) {
jsPsych.text = (function(){
var plugin = {};
plugin.create = function(params) {
var trials = new Array(params.text.length);
for(var i = 0; i < trials.length; i++)
{
trials[i] = {};
trials[i]["type"] = "text"; // must match plugin name
trials[i]["text"] = params.text[i]; // text of all trials
trials[i]["cont_key"] = params.cont_key || '13'; // keycode to press to advance screen, default is ENTER.
trials[i]["timing_post_trial"] = params.timing_post_trial || 0; // how long to delay between screens, default is no delay.
if(params.variables != undefined)
{
trials[i]["variables"] = params.variables[i]; // optional variables, defined as functions.
}
}
return trials;
}
plugin.trial = function(display_element, block, trial, part) {
// the text for the trial is in trial.text, but we need to replace any variables that are in the text.
var replaced_text = trial.text;
// check to see if there are any variables defined.
if(trial.variables != undefined)
{
for(var i = 0; i < trial.variables.length; i++)
{
// loop through the array of variables and call each variable function
// to get the actual text that should be substituted in.
var variable_text = trial.variables[i]();
// replace the "%v" with the return value of the function.
replaced_text = replaced_text.replace("%v", variable_text);
}
}
// set the HTML of the display target to replaced_text.
display_element.html(replaced_text);
// define a function that will advance to the next trial when the user presses
// the continue key.
var key_listener = function(e) {
if(e.which==trial.cont_key)
{
$(document).unbind('keyup',key_listener); // remove the response function, so that it doesn't get triggered again.
display_element.html(''); // clear the display
setTimeout(function(){block.next();}, trial.timing_post_trial); // call block.next() to advance the experiment after a delay.
}
}
var mouse_listener = function(e){
display_element.unbind('click', mouse_listener); // remove the response function, so that it doesn't get triggered again.
display_element.html(''); // clear the display
setTimeout(function(){block.next();}, trial.timing_post_trial); // call block.next() to advance the experiment after a delay.
}
// check if key is 'mouse'
if(trial.cont_key == 'mouse')
{
display_element.click(mouse_listener);
} else {
// attach the response function to the html document.
$(document).keyup(key_listener);
}
}
return plugin;
})();
}) (jQuery);