unify valueType and phetioType options

[pixelzoom]

While we're doing #189 (Simplify Property type validation) ...

Let's consider unifying valueType and phetioType options. They are currently 2 very different ways of expressing identical semantics. Duplicating this information is undesirable for both instrumentation and maintainability.

Examples...

GRAPHING_QUADRATICS/GQModel

      // @public {Property.<Quadratic|null>} the saved quadratic, null if nothing is saved
      this.savedQuadraticProperty = new Property( null, {
        isValidValue: value => ( value instanceof Quadratic || value === null ),
        ...
        phetioType: PropertyIO( NullableIO( QuadraticIO ) ),
        ...
      } );

GRAPHING_QUADRATICS/PointTool

      // @public {Vector2}
      this.locationProperty = new Property( options.location, {
        valueType: Vector2,
        ...
        phetioType: PropertyIO( Vector2IO ),
        ...
      } );

AXON/BooleanProperty (and similarly in NumberProperty and StringProperty)

  function BooleanProperty( value, options ) {

    options = _.extend( {
      phetioType: PropertyIO( BooleanIO )
    }, options );

    ...
    options.valueType = 'boolean';  // BooleanProperty requires values to be primitive booleans

    Property.call( this, value, options );
  }

[zepumph]

Wow what a great issue to create! We are looking into this for Emitter right now and it is going very well, see #190. To decide the main schema for determining what a "valid value" is, we will need to wait on the decision in #189

[pixelzoom]

See also #195, proper handling of valueType: Array.

[samreid]

On hold until #189 is complete.

[samreid]

See also #204, which is the same issue for Emitters.

[pixelzoom]

It seems like we addressed this in #189, where we concluded that these options will not be unified. @samreid @zepumph Can this issue be closed?

[samreid]

That sounds right to me, leaving up to @zepumph in case he has other thoughts or recommendations.

[zepumph]

where we concluded that these options will not be unified.

I think that you and I understand this in the same way @pixelzoom, though I want state the decision for this issue. Though they won't be unified via a mutual exclusion assertion, phetioType does cover valueType in most cases and, by convention, can/should be removed when the phetioType is provided. For example phetioType: NullableIO( BooleanIO ) is a superset of information of valueType: [ null, 'boolean' ], and so the valueType doesn't need to also be provided (and can be removed if already supplied). Closing