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

N.B. This function is automatically called by tas3_call() so making an explicit call is seldom needed. You may consider making such call if you need to know which EPR is actually found and you want to query some properties of the EPR. You can then pass the URL, as found using tas3_get_epr_url(), as an argument to tas3_call() to constrain the call to use a specific EPR.

First search the epr cache, and if there is a cache 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). String.

url

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

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. String.

n

Which matching instance is returned. 1 means first. Integer.

return

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