3.3.9 Explicit Discovery: epr = tas3_get_epr(cf, ses, svc, url, di_opt, act, n)

First search epr cache, and if miss, go discover an EPR over the net. This is the main work horse for WSCs wishing to call WSPs via EPR.

cf

TAS³ configuration object, also used for memory allocation

ses

Session object in whose EPR cache the file will be searched

svc

Service type (usually a URN)

url

(Optional) If provided, this argument has to match either the ProviderID, EntityID, or actual service endpoint URL.

di_opt

(Optional) Additional discovery options for selecting the service, query string format

act

(Optional) The action, or method, that must be invokable on the service

n

Which matching instance is returned. 1 means first

return

EPR data structure on success, 0 on failure (no discovery EPR in cache, or not found by the discovery service).