<cfcomponent output="false">

The OUTPUT attribute of the CFCOMPONENT tag suppresses output from the "pseudo-constructor" code: code that is within the CFCOMPONENT tags, but outwith any CFFUNCTION tags.  This code is run when the CFC is instantiated.

OUTPUT for CFCOMPONENT loks like it's a boolean, but it's actually tri-state:

OUTPUT=TRUE: behaves as if the whole thing is wrapped in CFOUTPUT tags

OUTPUT=FALSE: behaves as if the whole thign is wrapped in CFSILENT tags

OUTPUT=[not specified] behaves like normal CFML code: will output plain text, but to resolve dynamic values (eg: stuff within hash-marks / pound-signs), one needs to use CFOUTPUT tags.

I guess this is why it's not CFOUTPUT=FALSE by default.  If that was the default, then there'd be no way of reflecting that third state.

If I was architecting the CFC implementation, it'd be output=false by default, and if output=true then the code would act like any normal CFML: so like the current [not specified] behaviour.  I think the way OUTPUT=TRUE behaves is stupid: who the hell would want ALL their code in CFOUTPUT tags?

Does that answer your question(s)?

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Adam

Now... when you say you're doing them in CFScript, do you mean as per CF9's new "script-only CFCs"?  You can almost get away with not bothering with OUTPUT=FALSE in that case, as CFScript doesn't generate spurious output like tags do.

The only thing to watch for is if within your script-only CFC you call a non-script CFC method which doesn't have output suppressed: then its spurious output could still bleed out.

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Adam

Regarding "Why anyone would have code in a cfc outside a method that renders output to a page I really do have no idea"

cfc's are one of the ways to produce re-useable code.  Sometimes the code you want to re-use involves outputting to a page.

Yeah, but if that stuff you want to output is in the pseudo-constructor of the CFC... you're almost certainly going about things the wrong way.

Having spent a good 5sec thinking about it, I cannot think of any situation under which I would consider doing this to be appropriate.

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Adam

Dan Bracuk wrote:

 

Regarding "Why anyone would have code in a cfc outside a method that renders output to a page I really do have no idea"

cfc's are one of the ways to produce re-useable code.  Sometimes the code you want to re-use involves outputting to a page.

I would never say never to this. Da Vinci and Einstein had to flout convention to find new ways of doing things.

I believe setting output = 'false" in cfcs also helps prevent memory leaks (and heap dumps). I am not sure if CF9 does this or not as I always add the output = 'false" in the cffunction.

Hope it helps,

Bill