[OpenSIPS-Devel] Pseudovariable implementation extended

[Anca Vamanu]

Hi,

The pseudovariable implementation has been extended with new operations to give more power to the script writer:

1. Added 2 new operations on pseudovariables values from the script:
	- *delete* the pseudovariable at a certain index; syntax: *pvar[_index_]=NULL*.
	- *overwrite* the value of a pseudovariable at a certain index; syntax: *pvar[_index_]=_value_*.

2. Added one new function for avp: inserts a value to an avp set at a certain position
	- syntax: *avp_insert*
 
3. Added operations for set values of pseudovariables:
	- *count* the number of values; syntax: *set_count(_pvar_name_)*.
	- *select* an element from the set based on fitness. The selection algorithm is the genetic algorithm roulette-wheel selection. One usage example is selecting a route based on costs.
	 syntax: *set_select_weight(_pvar_name_)*; it returns the index of the selected value.

4. Added a new transformation: extract a parameter from a To like header
	- syntax: *{nameaddr.param,param_name}
	*- example:*'"test" <sip:test at opensips.org>;tag=dat43h' {nameaddr.param,tag} = dat43h
*

5. Added *context* meaning to pseudovariables - a new token added in front of the pv type name that specifies the context where the pv should be taken from
The implementation is made general - with a mechanism of registering pv context functions, allowing for extensions and addition of custom contexts. For now there are 2 pv contexts: reply and request, registered by the tm module.
	- example: -referencing *$(<request>ru)* from a reply route will get the Request-URI from the request
		   -the <reply> context can be used from failure route to access information from the reply


Hope you will find this useful.

Regards,
Anca