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SQL Anywhere 12.0.1 » SQL Anywhere Server - Programming » HTTP web services » HTTP web service examples

 

Sample: Handling SOAP headers, parameters, and responses

This sample illustrates different ways of exchanging SOAP requests between a web server and a SOAP client.

The following server-side code illustrates how a web server can process SOAP requests containing parameters, and SOAP headers. The example implements an addItem SOAP operation that takes two parameters: amount of type int and item of type string. The sp_addItems procedure also processes an Authentication SOAP header extracting the first and last name of the user. The values are used to populate a SOAP response Validation header via the sa_set_soap_header system procedure. The response is a result of three columns: quantity, item and status with types INT, LONG VARCHAR and LONG VARCHAR respectively.



// create the SOAP service
call sa_make_object( 'service', 'addItems' );
alter SERVICE "addItems"
    TYPE 'SOAP'
    format 'concrete'
    AUTHORIZATION OFF
    USER dba
    AS call sp_addItems( :amount, :item );

// create SOAP endpoint for related services
call sa_make_object( 'service', 'store' );
alter SERVICE "store"
    TYPE 'DISH'
    AUTHORIZATION OFF
    USER dba;

// create the procedure that will process the SOAP requests for the addItems service
create or replace procedure sp_addItems( "count" int, item long varchar )
result( quantity int, item long varchar, status long varchar )
begin
    declare "hd_key" long varchar;
    declare "hd_entry" long varchar;
    declare "pwd" long varchar;
    declare "first" long varchar;
    declare "last" long varchar;
    declare "xpath" long varchar;
    declare "authinfo" long varchar;
    declare "namespace" long varchar;
    declare "mustUnderstand" long varchar;

  header_loop:
    loop
        set hd_key = next_soap_header( hd_key );
        if hd_key is NULL then
      // no more header entries.
            leave header_loop;
        end if;
        if hd_key = 'Authentication' then
            set hd_entry = soap_header( hd_key );
            set xpath = '/*:' || hd_key || '/*:userName';
            set "namespace" = soap_header( hd_key, 1, '@namespace' );
            set mustUnderstand = soap_header( hd_key, 1, 'mustUnderstand' );
            begin
        // parse for the pieces that you are interested in
                declare crsr cursor for select * from
                    openxml( hd_entry, xpath )
                        with ( pwd long varchar '@*:pwd',
                               "first" long varchar '*:first/text()',
                               "last" long varchar '*:last/text()');
                open crsr;
                fetch crsr into pwd, "first", "last";
                close crsr;
            end;
      // build a response header, based on the pieces from the request header
            set authinfo = XMLELEMENT( 'Validation',
            XMLATTRIBUTES(
                    "namespace" as xmlns,
                    "mustUnderstand" as mustUnderstand ),
                    XMLELEMENT( 'first', "first" ),
                    XMLELEMENT( 'last', "last" ) );

            call sa_set_soap_header( 'authinfo', authinfo);
        end if;
    end loop header_loop;
    //  code to validate user/session and check item goes here...
    select count, item, 'available';
end;

The following client-side code illustrates how to create SOAP procedures and functions that send parameters and SOAP headers. Wrapper procedures are used to populate the web service procedure calls and process the responses. The soapAddItemProc procedure illustrates the use of a SOAP web service procedure, the soapAddItemFunction function illustrates the use of a SOAP web service function, and the httpAddItemFunction function illustrates how a SOAP payload may be passed to an HTTP web service procedure.



/* -- SOAP client procedure --
    uses substitution parameters to send SOAP headers
         a single inout parameter is used to receive SOAP headers
*/
create or replace procedure soapAddItemProc("amount" int, item long varchar, inout inoutheader long varchar, in inheader long varchar )
	url 'http://localhost/store'
    set 'SOAP( OP=addItems )'
    type 'SOAP:DOC'
	soapheader '!inoutheader!inheader';

/* Wrapper that calls soapAddItemProc
    demonstrates:
        how to send and receive soap headers
        how to send parameters
 */
create or replace procedure addItemProcWrapper( amount int, item long varchar, "first" long varchar, "last" long varchar )
    begin
        declare io_header long varchar;	// inout (write/read) soap header
        declare resxml long varchar;
        declare soap_header_sent long varchar;
        declare i_header long varchar;	// in (write) only soap header
        declare err int;
        declare crsr cursor for call soapAddItemProc( amount, item, io_header, i_header );

        set io_header = XMLELEMENT( 'Authentication',
			      	XMLATTRIBUTES('CustomerOrderURN' as xmlns),
                    XMLELEMENT('userName', XMLATTRIBUTES(
				            'none' as pwd,
				            '1' as mustUnderstand ),
                        	XMLELEMENT( 'first', "first" ),
                        	XMLELEMENT( 'last', "last" ) ) );
        set i_header = '<Session xmlns="SomeSession">123456789</Session>';
        set soap_header_sent = io_header || i_header;
        open crsr;
        fetch crsr into resxml, err;
        close crsr;

        select resxml, err, soap_header_sent, io_header as soap_header_received;
    end;
/* example call to addItemProcWrapper */
call addItemProcWrapper( 5, 'shirt', 'John', 'Smith' );


/* -- SOAP client function --
    uses substitution parameters to send SOAP headers
    Entire SOAP response envelope is returned.  SOAP headers can be parsed using openxml
*/
create or replace function soapAddItemFunction("amount" int, item long varchar, in inheader1 long varchar, in inheader2 long varchar )
returns XML
	url 'http://localhost/store'
    set 'SOAP( OP=addItems )'
    type 'SOAP:DOC'
	soapheader '!inheader1!inheader2';

/* Wrapper that calls soapAddItemFunction
    demonstrates the use of SOAP function:
        how to send and receive soap headers
        how to send parameters and process response
 */
create or replace procedure addItemFunctionWrapper( amount int, item long varchar, "first" long varchar, "last" long varchar )
    begin
        declare i_header1 long varchar;
        declare i_header2 long varchar;
        declare res long varchar;
        declare ns long varchar;
	    declare xpath long varchar;
	    declare header_entry long varchar;
	    declare localname long varchar;
	    declare namespaceuri long varchar;
        declare r_quantity int;
        declare r_item long varchar;
        declare r_status long varchar;
        

        set i_header1 = XMLELEMENT( 'Authentication',
			      	XMLATTRIBUTES('CustomerOrderURN' as xmlns),
                    XMLELEMENT('userName', XMLATTRIBUTES(
				            'none' as pwd,
				            '1' as mustUnderstand ),
                        	XMLELEMENT( 'first', "first" ),
                        	XMLELEMENT( 'last', "last" ) ) );
        set i_header2 = '<Session xmlns="SessionURN">123456789</Session>';

        set res = soapAddItemFunction( amount, item, i_header1, i_header2 );

	     set ns = '<ns xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"'
		|| ' xmlns:mp="urn:ianywhere-com:sa-xpath-metaprop"'
        || ' xmlns:customer="CustomerOrderURN"'
        || ' xmlns:session="SessionURN"'
		|| ' xmlns:tns="http://localhost"></ns>';

        // Process headers...	     
        set xpath = '//SOAP-ENV:Header/*';
	    begin
	     declare crsr cursor for select * from
		     openxml( res, xpath, 1, ns )
                          with (  "header_entry" long varchar '@mp:xmltext',
        				"localname" long varchar '@mp:localname',
        				"namespaceuri" long varchar '@mp:namespaceuri' );
            open crsr;
            fetch crsr into "header_entry", "localname", "namespaceuri";
            close crsr;
        end;

        // Process body...
        set xpath = '//tns:row';
	    begin
	     declare crsr1 cursor for select * from
		     openxml( res, xpath, 1, ns )
                          with (  "r_quantity" int 'tns:quantity/text()',
        				"r_item" long varchar 'tns:item/text()',
        				"r_status" long varchar 'tns:status/text()' );
            open crsr1;
            fetch crsr1 into "r_quantity", "r_item", "r_status";
            close crsr1;
        end;

    select r_item, r_quantity, r_status, header_entry, localname, namespaceuri;
    end;

/* example call to addItemFunctionWrapper */
call addItemFunctionWrapper( 5, 'shirt', 'John', 'Smith' );

/*
 Demonstrate how a HTTP:POST can be used as a transport for a SOAP payload
 Rather than creating a webservice client SOAP procedure, this approach
 creates a webservice HTTP procedure that transports a SOAP payload
*/
create or replace function httpAddItemFunction("soapPayload" xml )
returns XML
	url 'http://localhost/store'
    type 'HTTP:POST:text/xml'
    header 'SOAPAction: "http://localhost/addItems"';


/* Wrapper that calls soapAddItemFunction
    demonstrates the use of SOAP function:
        how to send and receive soap headers
        how to send parameters and process response
 */

create or replace procedure addItemHttpWrapper( amount int, item long varchar )
result(response xml)
begin
    declare payload xml;
    declare response xml;

    set payload =
'<?xml version="1.0"?>
<SOAP-ENV:Envelope
  xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:m="http://localhost">
  <SOAP-ENV:Body>
    <m:addItems>
      <m:amount>' || amount || '</m:amount>
      <m:item>' || item || '</m:item>
    </m:addItems>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>';
    set response = httpAddItemFunction( payload );
    /* process response as demonstrated in addItemFunctionWrapper */
    select response;
end
go

/* example call to addItemHttpWrapper */
call addItemHttpWrapper( 5, 'shirt' );
 See also