Use variables for URI in WSDL mediators WSO2 - wso2

Question

I am re-factorizing a wso2 project and I wondered how/whether I could do the following. This project is designed to send data to a SOAP Api. In every environment, this API exposes a .wsdl file and the URL and credentials are the only things changing from one environment to another. The most natural thing to do is thus to
create those in the Registry and
load it in the beginning of the job like so
<propertyGroup>
<property expression="get-property('registry', 'gov:/endpoints/sap_constructionSiteUser')" name="sap_constructionSiteUser" scope="default" type="STRING"/>
<property expression="get-property('registry', 'gov:/endpoints/sap_constructionSitePassword')" name="sap_constructionSitePassword" scope="default" type="STRING"/>
<property expression="get-property('registry', 'gov:/endpoints/sap_constructionSiteUrl')" name="uri.var.sap_constructionSiteUrl" scope="default" type="STRING"/>
</propertyGroup>
But I could not find a straightforward way to use this uri.var.sap_constructionSiteUrl in the endpoint definition. The following does not work
<call>
<endpoint>
<wsdl optimize="mtom" uri="{uri.var.sap_constructionSiteUrl}" port="OUVERTURE_CHANTIER" service="OUVERTURE_CHANTIER" statistics="enable">
<suspendOnFailure>
<initialDuration>-1</initialDuration>
<progressionFactor>-1</progressionFactor>
<maximumDuration>0</maximumDuration>
</suspendOnFailure>
<markForSuspension>
<retriesBeforeSuspension>0</retriesBeforeSuspension>
</markForSuspension>
</wsdl>
</endpoint>
</call>
Looks like uri= only accept plain value. Is there a way I could made this dynamic without writing the entire endpoint in the Registry (the point is to keep things simple for the clients)
[Environment]
wso2ei 6.5.0
====================EDIT========================
I just created a template:
<template name="crm4sap-constructionSiteTemplate" xmlns="http://ws.apache.org/ns/synapse">
<axis2ns488:parameter name="port" xmlns:axis2ns488="http://ws.apache.org/ns/synapse"/>
<axis2ns489:parameter name="service" xmlns:axis2ns489="http://ws.apache.org/ns/synapse"/>
<axis2ns490:parameter name="uri" xmlns:axis2ns490="http://ws.apache.org/ns/synapse"/>
<endpoint name="$name">
<wsdl port="$port" service="$service" uri="$uri">
<suspendOnFailure>
<initialDuration>-1</initialDuration>
<progressionFactor>1.0</progressionFactor>
</suspendOnFailure>
<markForSuspension>
<retriesBeforeSuspension>0</retriesBeforeSuspension>
</markForSuspension>
</wsdl>
</endpoint>
</template>
And I call it with
<call>
<endpoint name="constructionSiteEndpoint" template="crm4sap-constructionSiteTemplate">
<axis2ns468:parameter name="port" value="OUVERTURE_CHANTIER" xmlns:axis2ns468="http://ws.apache.org/ns/synapse"/>
<axis2ns469:parameter name="service" value="OUVERTURE_CHANTIER" xmlns:axis2ns469="http://ws.apache.org/ns/synapse"/>
<axis2ns469:parameter name="uri" value="{$ctx:sap_constructionSiteUrl}" xmlns:axis2ns469="http://ws.apache.org/ns/synapse"/>
</endpoint>
</call>
Variable substitution does not seem to occur:
[2020-04-15 12:30:54,032] [] WARN - TemplateEndpointFactory Could not read the WSDL endpoint {$ctx:sap_constructionSiteUrl}
java.net.MalformedURLException: no protocol: {$ctx:sap_constructionSiteUrl}
at java.net.URL.<init>(URL.java:600)
at java.net.URL.<init>(URL.java:497)
at java.net.URL.<init>(URL.java:446)
Looks like a common problem

Answer 1

You can try to template this endpoint and then call the template with the parameters. You can pass dynamic values to the template in the runtime.
https://docs.wso2.com/display/EI650/Endpoint+Template

Answer 2

I was able to do it using the following code in the sequence:
<call-template target="template-for-calling-soap">
<with-param name="url" value="{get-property('soap-uri')}"/>
</call-template>
Where soap-uri is a local entry or a simple property, and the sequence template named template-for-calling-soap takes as parameter the url value and has the following code:
<template name="template-for-calling-soap"
xmlns="http://ws.apache.org/ns/synapse">
<parameter name="url"/>
<sequence>
<property expression="$func:url" name="uri.var" scope="default"
type="STRING"/>
<send>
<endpoint>
<address format="soap11" uri="${uri.var}"/>
</endpoint>
</send>
</sequence>
</template>