EVAL_EXTEN()¶

Synopsis¶

Evaluates the contents of a dialplan extension and returns it as a string.

Description¶

The EVAL_EXTEN function looks up a dialplan entry by context,extension,priority, evaluates the contents of a Return statement to resolve any variable or function references, and returns the result as a string.

You can use this function to create simple user-defined lookup tables or user-defined functions.

Example: Custom dialplan functions

[call-types]
exten => _1NNN,1,Return(internal)
exten => _NXXNXXXXXX,1,Return(external)

[udf]
exten => calleridlen,1,Return(${LEN(${CALLERID(num)})})

[default]
exten => _X!,1,Verbose(Call type ${EVAL_EXTEN(call-types,${EXTEN},1)} - ${EVAL_EXTEN(udf,calleridlen,1)})

Any variables in the evaluated data will be resolved in the context of that extension. For example, '${EXTEN}' would refer to the EVAL_EXTEN extension, not the extension in the context invoking the function. This behavior is similar to other applications, e.g. 'Gosub'.

Example: Choosing which prompt to use

same => n,Read(input,${EVAL_EXTEN(prompts,${CALLERID(num)},1)})

[prompts]
exten => _X!,1,Return(default)
exten => _20X,1,Return(welcome)
exten => _2XX,1,Return(${DB(promptsettings/${EXTEN})})
exten => _3XX,1,Return(${ODBC_MYFUNC(${EXTEN})})

Extensions on which EVAL_EXTEN is invoked are not different from other extensions. However, the application at that extension is not executed. Only the application data is parsed and evaluated.

A limitation of this function is that the application at the specified extension isn't actually executed, and thus unlike a Gosub, you can't pass arguments in the EVAL_EXTEN function.

If you need the ability to evaluate more complex logic that cannot be done purely using functions, see 'EVAL_SUB'.

Syntax¶

EVAL_EXTEN(context,extensions,priority)

Arguments¶

context
extensions
priority

Generated Version¶

This documentation was generated from Asterisk branch 21 using version GIT