BrightScript m variable


BrightScript is the language to program Roku streaming player.
The m keyword can be confusing.
code snippet from source/main.brs tagged with MvsThis, which stands for m vs this.

Function MvsThisCreate() as Object
	print "MvsThisCreate entered"
	obj = CreateObject("roAssociativeArray")
	obj.svc = "MvsThisSvc"
	obj.MvsThisFunc = MvsThisFunc
	obj.MvsThisFunc2 = MvsThisFunc2
	return obj
End Function

Function MvsThisFunc() as Void
	print "MvsThisFunc entered"
	print "MvsThisFunc m.svc="m.svc
	print "MvsThisFunc m.MvsThisFunc2="m.MvsThisFunc2
	print "MvsThisFunc MvsThisFunc2="MvsThisFunc2
	m.MvsThisFunc2("m.MvsThisFunc2")
	MvsThisFunc2("MvsThisFunc2")
End Function

Function MvsThisFunc2(str as String) as Void
	print "MvsThisFunc2 called by: "str
End Function

Function MvsThisTest() as Void
	print "MvsThisTest start"
	MvsThis = MvsThisCreate()
	MvsThis.MvsThisFunc()
	print "MvsThisTest done"
End Function

When we run MvsThisTest(), we get these output:

	MvsThisTest start
	MvsThisCreate entered
	MvsThisFunc entered
	MvsThisFunc m.svc=MvsThisSvc
	MvsThisFunc m.MvsThisFunc2=<Function: mvsthisfunc2>
	MvsThisFunc MvsThisFunc2=<Function: mvsthisfunc2>
	MvsThisFunc2 called by: m.MvsThisFunc2
	MvsThisFunc2 called by: MvsThisFunc2

As shown above, m is for accessing data in roAssociativeArray from roAssociativeArray’s function fields.
Calling m.MvsThisFunc2( and MvsThisFunc2(, without the m. are the same thing when the object is roAssociativeArray.
Calling m.MvsThisFunc2() doesn’t work if the object is SceneGraph node, e.g. loaded as xml file.

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