When to use NoOp() and Verbose()

The difference between Verbose() and NoOp() is subtle. Here are some suggestions as to how you can discern when to use each. The Verbose() application is handy when you want to output something to the console. Using the set verbose command (followed by the level of verbosity you desire—0 to 4), you can set the output to a level that will not show you all of the activity on the system, but rather only those things that are equal to or less than that the current level. (Actually, you can set the verbosity to whatever you want. The set verbose 999 will work just fine, but we have not been able to find anything that outputs at a level higher than 4, so anything from 4 to infinity will be effectively the same for the time being.) This means that you can display all kinds of information pertaining to a section of code you are testing, without having to see all of the other activity in the system. If you set the following in your dial plan:

exten => _X.,n,Verbose(2, ${SOME_VAR})

You can then use the CLI to set the verbosity to 2 or less (core set verbose 2), and you will see output from the various calls to Verbose(), but very little else.

Read the section on Verbose() later in this appendix for more on how to use it. The NoOp() application is best used as a place holder. For example, if you are setting a Goto() point in your dialplan that is using a priority label, you can use NoOp() as the destination point for that goto. For example,

exten => _X.,n(call_forward),NoOp()

is an excellent marker for pointing a jump in your dialplan to a spot. From that point you can carry on with whatever logic you wanted to apply to that part of the extension (judging by the label, it’d have something to do with call forwarding). The value of the NoOp() is that when you don’t really know what sort of things you might want to move around in relation to what follows that label, you can be sure you’ll never have to recode the label itself. It will never do anything other than provide a destination for the Goto(), so you can put it wherever you like and be sure it won’t introduce any unexpected behavior.

If this seems confusing, it is due to our inability to describe it right. Experiment with Verbose() and NoOp() all in your dialplan (you can use them anywhere), and you will quickly gain an understanding of how they can help you (especially if you are like us and cause a lot of syntax errors).