SERVICE Structure<indexterm>
<primary>SERVICE Structure</primary>
</indexterm>servicename := SERVICE [ :
defaultkeywords
] prototype :
keywordlist;END;servicenameThe name of the service the SERVICE structure
provides.defaultkeywordsOptional. A comma-delimited list of default keywords and
their values shared by all prototypes in the external
service.prototypeThe ECL name and prototype of a specific function.keywordlistA comma-delimited list of keywords and their values that
tell the ECL compiler how to access the external service.The SERVICE structure makes it
possible to create external services to extend the capabilities of ECL to
perform any desired functionality. These external system services are
implemented as exported functions in a .SO (Shared Object). An ECL system
service .SO can contain one or more services and (possibly) a single .SO
initialization routine.Example: email := SERVICE
simpleSend( STRING address,
STRING template,
STRING subject) : LIBRARY='ecl2cw',
INITFUNCTION='initEcl2Cw';
END;
MyAttr := COUNT(Trades): FAILURE(email.simpleSend('help@ln_risk.com',
'FailTemplate',
'COUNT failure'));
//An example of a SERVICE function returning a structured record
NameRecord := RECORD
STRING5 title;
STRING20 fname;
STRING20 mname;
STRING20 lname;
STRING5 name_suffix;
STRING3 name_score;
END;
LocalAddrCleanLib := SERVICE
NameRecord dt(CONST STRING name, CONST STRING server = 'x')
: c,entrypoint='aclCleanPerson73',pure;
END;
MyRecord := RECORD
UNSIGNED id;
STRING uncleanedName;
NameRecord Name;
END;
x := DATASET('x', MyRecord, THOR);
myRecord t(myRecord L) := TRANSFORM
SELF.Name := LocalAddrCleanLib.dt(L.uncleanedName);
SELF := L;
END;
y := PROJECT(x, t(LEFT));
OUTPUT(y);
//The following two examples define the same functions:
TestServices1 := SERVICE
member(CONST STRING src)
: holertl,library='test',entrypoint='member',ctxmethod;
takesContext1(CONST STRING src)
: holertl,library='test',entrypoint='takesContext1',context;
takesContext2()
: holertl,library='test',entrypoint='takesContext2',context;
STRING takesContext3()
: holertl,library='test',entrypoint='takesContext3',context;
END;
//this form demonstrates the use of default keywords
TestServices2 := SERVICE : holert,library='test'
member(CONST STRING src) : entrypoint='member',ctxmethod;
takesContext1(CONST STRING src) : entrypoint='takesContext1',context;
takesContext2() : entrypoint='takesContext2',context;
STRING takesContext3() : entrypoint='takesContext3',context;
END;
See Also: External Service Implementation, CONST