Local

data and meta are variables specific to the scope of specific elements.

The variables that we’ve discussed so far are relevant for whole tasks or even whole studies. We now approach variables that have a narrower scope: they have to do with specific elements within your task. These variables are called Data and Meta.

Data

The Data variables allow you to manually set useful information into each element. Their behaviour is described fully within as part of element inheritance.

In the following example, the data set in the ‘default’ task, is used from within a template in the sequence.

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define(['managerAPI'], function(Manager){

  var API = new Manager();

  API.addTasksSet('default', [
  	{
  		type:'message',
  		keys: ' ',
        data: {condition:'using data in templates'}
  	}
  ]);

  API.addSequence([
    {inherit:'default',template:'We are in the "<%= tasksData.condition %>" condition.'}
  ]);

  return API.script;
});

Meta

The Meta variables hold some meta information regarding this element that is auto-generated by the mixer. The meta objects have two properties number and outOf:

Property	Description
number	The serial number for this element within the sequence (i.e. 3 if this is the third element to be presented).
outOf	An attempt to estimate how many elements are in the sequence overall. This number cannot be fully trusted as the number of elements may be dynamically generated and depend on various variables not yet determined.

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define(['managerAPI'], function(Manager){

  var API = new Manager();

  API.addTasksSet('default', [
  	{
  		type:'message',
  		keys: ' ',
        template: 'Task number <%= tasksMeta.number %> out of <%= tasksMeta.outOf %>.'
  	}
  ]);

  API.addSequence([
    {inherit:'default'},
    {inherit:'default'},
    {inherit:'default'},
    {inherit:'default'}
  ]);

  return API.script;
});

Naming convention

The naming convention for these variables is <elementName>Data and <elementName>Meta respectively. For example, for tasks they appear as tasksData and tasksMeta.

The elementNames for the various tasks are as follows:

Task	elementName	Object names
miManager	tasks	tasksData, tasksMeta
miQuest	pages	pagesData, pagesMeta
questions	questionsData, questionsMeta
miTime	trial	trialData, trialMeta
stimulus	stimulusData, stimulusMeta
media	mediaData, mediaMeta

Last modified March 11, 2021: setup hugo (11980dc)