Using Erlang for Comsuming Web Services using SOAP

[Erik Reitsma EJ (RY/ETM)]

Hi Neil,

I wrote that library for some SOAP stuff I had to do. No documentation exists (to my knowledge), because I used to be the only user. I am already proud that I put some comments in the source. :) Then I decided to give away the code, but without putting more effort in it. So, it is as it is.
I have used it mainly as a SOAP server, but there is a small client part too. I have not used that for a while, so it may be incompatible with recent inets changes. It is also written when xmerl-0.19 or even earlier was available, so it may be incompatible with the latest (official) xmerl. I have not tried that.
I am not sure when I am going to use this library again myself, so it is not actively maintained. It is "dormant", but I may wake it up when I need it.
I am sure that my SOAP implementation leaves a lot to be desired, but for my needs it was good enough.

About the client part. Before you can call soapclient:invoke/4 you have to define the operations, types and messages you want to use. (It would be nice if this could be generated from WSDL.) 
Example:

-include("erlsoap.hrl").

-define(PARLAYX_SMS_XSD_URI,'http://www.csapi.org/schema/parlayx/common/v1_0').

add_messages() ->
    %% sendSms operation
    erlsoap:add_operation({'http://www.csapi.org/wsdl/parlayx/sms',
				"sendSms"},
			       {'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_sendSmsRequest"},
			       {'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_sendSmsResponse"},
			       []),
    %% sendSms request message
    erlsoap:add_message({'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_sendSmsRequest"},
			     [{"destinationAddressSet",{?PARLAYX_SMS_XSD_URI,"ArrayOfEndUserIdentifier"}},
			      {"senderName",{?XMLSchemaURI,"string"}},
			      {"charging",{?XMLSchemaURI,"string"}},
			      {"message",{?XMLSchemaURI,"string"}}]),
    %% sendSms response message
    erlsoap:add_message({'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_sendSmsResponse"},
			     [{{?PARLAYX_SMS_XSD_URI,"result"},
			       {?XMLSchemaURI,"string"}
			      }
			     ]),

    %% getSmsDeliveryStatus operation
    erlsoap:add_operation({'http://www.csapi.org/wsdl/parlayx/sms',
				"getSmsDeliveryStatus"},
			       {'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_getSmsDeliveryStatusRequest"},
			       {'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_getSmsDeliveryStatusResponse"},
			       []),
    %% getSmsDeliveryStatus request message
    erlsoap:add_message({'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_getSmsDeliveryStatusRequest"},
			     [{"requestIdentifier",{?XMLSchemaURI,"string"}}]),
    %% getSmsDeliveryStatus response message
    erlsoap:add_message({'http://www.csapi.org/wsdl/parlayx/sms/v1_0/service',
			      "SendSMS_getSmsDeliveryStatusResponse"},
			     [{{?PARLAYX_SMS_XSD_URI,"result"},
			       {'http://www.csapi.org/schema/parlayx/sms/v1_0',"ArrayOfDeliveryStatusType"}
			      }
			     ]),


    %% EndUserIdentifier type
    erlsoap:add_type({?PARLAYX_SMS_XSD_URI,"EndUserIdentifier"},
			  {complex_type,
			   {sequence,
			    [{"value",{?XMLSchemaURI,"string"},0,1}]
			   }
			  }),

    erlsoap:add_type({'http://www.csapi.org/schema/parlayx/sms/v1_0',"ArrayOfDeliveryStatusType"},
			  {complex_type,
			   {sequence,
			    [{"ArrayOfDeliveryStatusType",
			      {'http://www.csapi.org/schema/parlayx/sms/v1_0',
			       "DeliveryStatusType"},0,unbounded}
			     ]
			    }
			  }),

     erlsoap:add_type({?PARLAYX_SMS_XSD_URI,"ArrayOfEndUserIdentifier"},
 		     {complex_type,
 		      {array,
		       {?PARLAYX_SMS_XSD_URI,"EndUserIdentifier"}
 		      }
 		     }),

    erlsoap:add_type({'http://www.csapi.org/schema/parlayx/sms/v1_0',"ArrayOfSmsType"},
			  {complex_type,
			   {sequence,
			    [{"ArrayOfSmsType",
			      {'http://www.csapi.org/schema/parlayx/sms/v1_0',
			       "SmsType"},0,unbounded}
			     ]
			    }
			  }),

    erlsoap:add_type({'http://www.csapi.org/schema/parlayx/sms/v1_0',"DeliveryStatusType"},
			  {complex_type,
			   {sequence,
			    [{"destinationAddress",
			      {?PARLAYX_SMS_XSD_URI,
			       "EndUserIdentifier"},0,1},
			     {"deliveryStatus",
			      {'http://www.csapi.org/schema/parlayx/sms/v1_0',"DeliveryStatus"},0,1}
			    ]
			   }
			  }
			 ),

    erlsoap:add_type({'http://www.csapi.org/schema/parlayx/sms/v1_0',"SmsType"},
			  {complex_type,
			   {sequence,
			    [{"message",{?XMLSchemaURI,"string"}},
			     {"senderAddress",
			      {?PARLAYX_SMS_XSD_URI,
			       "EndUserIdentifier"},0,1}
			    ]
			   }
			  }
			 ),

    erlsoap:add_type({'http://www.csapi.org/schema/parlayx/sms/v1_0',"DeliveryStatus"},
			  {simple_type,{restriction,
					[{?XMLSchemaURI,"string"}],
					[{enumeration,'Delivered'},
					 {enumeration,'DeliveryUncertain'},
					 {enumeration,'DeliveryImpossible'},
					 {enumeration,'MessageWaiting'}]
				       }
			  }),

    erlsoap:add_type({'http://www.csapi.org/schema/parlayx/sms/v1_0',"SmsFormat"},
			  {simple_type,{restriction,
					[{?XMLSchemaURI,"string"}],
					[{enumeration,'Ems'},
					 {enumeration,'SmartMessaging'}]
				       }
			  }).

Then you should be able to call the service:

send_sms_local(X,Message) ->
    soapclient:invoke("http://some.host.com:8888/soap/rpcrouter",
		       "\"SendSMS#sendSms\"",
		       {'http://www.csapi.org/wsdl/parlayx/sms',
				"sendSms"},
		       [[[X]],["tel:1234"],"no bill",Message]).

I hope this helps a little.

Kind regards,
*Erik.