Inheritance
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Inheritance
In this tutorial we will learn how to create sets of Trials/Stimuli/Media and use them for randomization.
Sets are essentialy lists of objects that allow us to select objects out of them. The typical set definition looks something like this:
API.addMediaSet('setName',[
media1,
media2
]);
Using objects from a set is simple. all you have to do is add the inherit property to the inheriting object.
There are two syntax types for inheriting.
The simplified version randomly inherits a media object form the set 'mediaSet':
media: {inherit: 'mediaSet'}
The full syntax allows you to pick the inheritance type:
media: {
inherit: {
set: 'mediaSet',
type: 'exRandom'
}
}
// # Inheritance
// In this tutorial we will learn how to create sets of Trials/Stimuli/Media and use them for randomization.
// Sets are essentialy lists of objects that allow us to select objects out of them.
// The typical set definition looks something like this:
// API.addMediaSet('setName',[
// media1,
// media2
// ]);
// Using objects from a set is simple. all you have to do is add the `inherit` property to the inheriting object.
// There are two syntax types for inheriting.
// The simplified version randomly inherits a media object form the set 'mediaSet':
// media: {inherit: 'mediaSet'}
// The full syntax allows you to pick the inheritance type:
// media: {
// inherit: {
// set: 'mediaSet',
// type: 'exRandom'
// }
// }
define(['pipAPI'], function(APIconstructor) {
var API = new APIconstructor();
// #### media sets
// We define a set of media objects and call it *good*.
API.addMediaSets('good', [
{word: 'Paradise'},
{word: 'Pleasure'},
{word: 'Cheer'},
{word: 'Wonderful'},
{word: 'Splendid'},
{word: 'Love'}
]);
// We define a set of media objects and call it *bad*.
API.addMediaSets('bad', [
{word: 'Bomb'},
{word: 'Abuse'},
{word: 'Sadness'},
{word: 'Pain'},
{word: 'Poison'},
{word: 'Grief'}
]);
// #### Stimulus sets
// We define two types of stimuli: bad media on the left, good media on the right.
// This way, we use inheritance to style each media set in a uniform way.
API.addStimulusSets("Default", [
// randomly inherit a media object from the 'bad' media set
{
data: {type:'bad'},
location: {left:30},
media: {inherit:'bad'}
},
// randomly inherit a media object from the 'good' media set
{
data: {type:'good'},
location: {right:30},
media: {inherit:'good'}
}
]);
// #### Trial sets
// We define only one trial, this is inherantly gives us a shortcut to this trial, and will eventuall allow us to use it as a prototype. </br>
// This trial simply displays a random stimulus.
API.addTrialSets("Default", [
{
input: [{handle: 'end', on:'space'}],
layout: [{inherit:'Default'}],
interactions: [
{
conditions: [{type:'inputEquals',value:'end'}],
actions: [{type:'endTrial'}]
}
]
}
]);
// #### sequence
API.addSequence([
// ##### Simple inheritance
// We can simply inherit the Default trial and have it display random stimuli.
{inherit:'Default'},
{inherit:'Default'},
{inherit:'Default'},
// ##### Exclusive Randomization
// `exRandom`: pick a random object with exclusion.
// Repeated calls to `exRandom` will not return the same object until all objects in the set have been used. </br>
// Specificaly this Trial presents a random 'bad' media object (note that in this case we inherit a media object, not a stimulus).
{
input: [{handle: 'end', on:'space'}],
layout: [
/* begin stimulus */
{
/* begin media */
media: {
inherit:{
set:'bad',
type:'exRandom'
}
}
/* end media */
}
/* end stimulus */
],
interactions: [
{
conditions: [{type:'inputEquals',value:'end'}],
actions: [{type:'endTrial'}]
}
]
},
// ##### Inherit by Data
// `byData` checks if the inherit objtects' `data` property is a subset of the elements' `data` property and if it is it picks the element.
// (this means that if all properties of `data` equal to the properties of the same name in `element.data` it is a fit). </br>
// Specificaly, this trial picks the stimulus that has `data:{type:'good'}` (note that in this case we inherit a whole stimulus object).
{
input: [{handle: 'end', on:'space'}],
layout: [
/* begin stimulus */
{
inherit:{
set:'Default',
type:'byData',
data: {type:'good'}
}
}
/* end stimulus */
],
interactions: [
{
conditions: [{type:'inputEquals',value:'end'}],
actions: [{type:'endTrial'}]
}
]
},
// ##### Prototyping
// One of the greatest powers of inheritance is prototyping; using a the inheritance as a template for more advanced elements.
// When an element (the child) has an inherit property, then the child is used to extend the inherited element (the parent).
// What this means is that inherited properties are overwritten by explicit properties. Let's see how this works.
{
// Inherit the 'Default' trial.
inherit: 'Default',
// The layout property gets overridden
layout: [{media:{word:'One Child'}}]
},
{
// Inherit the 'Default' trial.
inherit: 'Default',
// The layout property gets overriden in a different way.
layout: [{media:{word:'A differen child'}}]
}
]);
return API.script;
});
License: Apache 2. © Project Implicit. · Current version [version]