coldfusioncoldfusion-7

How does Coldfusion deal with createObject internally?

Say I want to call a static function from a CFC from within a cfscript block. As far as I know, the only method is using createObject() which returns a reference to the CFC object.

Is this good practice? I think I remember reading that cfinvoke definitely instanciated objects smartly and would not instanciate a static CFC multiple times. Is this even true, and if so, is this still true when using createObject()?

Solution

  • CFOBJECT

    CFOBJECT instantiates a component and creates a variable for it.

    <cfobject type="component" name="path.to.my.CFC" name="myCFC" />

    CFINVOKE

    CFINVOKE can then reference the variable created by CFOBJECT, so that it doesn't have to re-create the object again.

    <cfinvoke component="#myCFC#" method="foo" returnVariable="myValue" />

    So you can call as many CFINVOKEs as you want on #myCFC# without recreating the object.

    However, CFINVOKE can also implicitly create the object for you if you don't also use CFOBJECT.

    <cfinvoke component="path.to.my.CFC" method="foo" returnVariable="myValue" />

    Calling multiple functions in this manner will recreate the object each time.

    CREATEOBJECT

    createObject() works pretty much the same way. Either create the object first with a reference variable

    <cfscript>
myCFC = createObject("component", "path.to.my.CFC");
myValue = myCFC.foo();
otherValue = myCFC.bar();
</cfscript>

    or create the object with each function call.

    <cfscript>
myValue = createObject("component", "path.to.my.CFC").foo();
otherValue = createObject("component", "path.to.my.CFC").bar();
</cfscript>

    I prefer createObject() since I've been using CFSCRIPT as much as possible. And I always create the object first if I'm going to call multiple functions from it.