adql.query.operand.function

Class UserDefinedFunction

java.lang.Object

adql.query.operand.function.ADQLFunction

adql.query.operand.function.UserDefinedFunction

All Implemented Interfaces:

ADQLObject, ADQLOperand, UnknownType

Direct Known Subclasses:

DefaultUDF

public abstract class UserDefinedFunction
extends ADQLFunction
implements UnknownType

Function defined by the user (i.e. PSQL functions).

Version:

1.3 (02/2015)

Author:

Grégory Mantelet (CDS;ARI)

See Also:

DefaultUDF

Nested Class Summary

Nested classes/interfaces inherited from class adql.query.operand.function.ADQLFunction

ADQLFunction.ParameterIterator

Constructor Summary

Constructors

Constructor and Description
UserDefinedFunction()

Method Summary

Modifier and Type	Method and Description
char	getExpectedType() Get the type expected by the syntactic parser according to the context.
void	setExpectedType(char c) Set the type expected for this operand.
abstract java.lang.String	translate(ADQLTranslator caller) Translate this User Defined Function into the language supported by the given translator.

Methods inherited from class adql.query.operand.function.ADQLFunction

adqlIterator, getNbParameters, getParameter, getParameters, getPosition, paramIterator, setParameter, setPosition, toADQL

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface adql.query.operand.ADQLOperand

isGeometry, isNumeric, isString

Methods inherited from interface adql.query.ADQLObject

adqlIterator, getCopy, getName, getPosition, toADQL

Constructor Detail

UserDefinedFunction

public UserDefinedFunction()

Method Detail

getExpectedType

public char getExpectedType()

Description copied from interface: UnknownType

Get the type expected by the syntactic parser according to the context.

Specified by:

getExpectedType in interface UnknownType

Returns:

Expected type: 'n' or 'N' for numeric, 's' or 'S' for string, 'g' or 'G' for geometry.

setExpectedType

public void setExpectedType(char c)

Description copied from interface: UnknownType

Set the type expected for this operand.

Specified by:

setExpectedType in interface UnknownType

Parameters:

c - Expected type: 'n' or 'N' for numeric, 's' or 'S' for string, 'g' or 'G' for geometry.

translate

public abstract java.lang.String translate(ADQLTranslator caller)
                                    throws TranslationException

Translate this User Defined Function into the language supported by the given translator.

VERY IMPORTANT: This function MUST NOT use ADQLTranslator.translate(UserDefinedFunction) to translate itself. The given ADQLTranslator must be used ONLY to translate UDF's operands.

Implementation example (extract of DefaultUDF.translate(ADQLTranslator)):

 public String translate(final ADQLTranslator caller) throws TranslationException{
        StringBuffer sql = new StringBuffer(functionName);
        sql.append('(');
        for(int i = 0; i < parameters.size(); i++){
                if (i > 0)
                        sql.append(',').append(' ');
                sql.append(caller.translate(parameters.get(i)));
        }
        sql.append(')');
        return sql.toString();
 }
 

Parameters:

caller - Translator to use in order to translate ONLY function parameters.

Returns:

The translation of this UDF into the language supported by the given translator.

Throws:

TranslationException - If one of the parameters can not be translated.

Since:

1.3