How to parse XML document returned by webservices

Question

Hi,
I have a form (version 10.1.2.0) which has to display the credit card types using webservices. I created the webstub and jar file through jdeveloper and then after adding the jar files in the respective classpaths, I import it in the forms. I write the code in when-button-pressed and it gives the result in xml document like this:
<?xml version="1.0" encoding="UTF-8"?><WSAnswerTO><error>false</error><errorMessage></errorMessage><
results><CardTypeTO><carTypId>3</carTypId><type>AMERICAN
EXPRESS</type><numLength>15</numLength><cvvLength>4</cvvLength><comments>1 800-639-0002</comments></CardTypeTO><CardTypeTO><carTypId>4</carTypId><type>DISCOVER</type><numLength>16</numLength><cvvLength>3</cvvLength><comments>1 800-347-2683</comments></CardTypeTO><CardTypeTO><carTypId>1</carTypId><type>MASTERCARD</type><numLength>16</numLength><cvvLength>3</cvvLength><comments>1 800-633-7367</comments></CardTypeTO><CardTypeTO><carTypId>2</carTypId><type>VISA</type><numLength>16</numLength><cvvLength>3</cvvLength><comments>1 800-945-2000</comments></CardTypeTO></results></WSAnswerTO>
From the above xml document, I only need to display the type (such as AMERICAN EXPRESS, VISA, ETC) in my forms. Can somebody please tell me how to do it. Do I need to store the values in a table first and then retrieve it. Please advise. I have already read a otn document in xml parsing but I didnt understand anything from it.
Please help. Thanks in advance.

Answer 1

Hello,
It probably exists a database package/function to parse this kind of stuff.
If you want to keep the process into the Forms, here is a PL/SQL package you can use:
CREATE OR REPLACE PACKAGE Pkg_Tools AS
  --  Types  --
  -- table of strings --
  TYPE TYP_TAB_CHAR IS TABLE OF VARCHAR2(4000) INDEX BY BINARY_INTEGER;
  --  Methodes   --
  -- function that return all contents for a given XML tag --
  FUNCTION Get_Xml_Tag
     PC$XmlContent  IN VARCHAR2,                 -- XML string
     PC$Tag         IN VARCHAR2,                 -- searched tag
     PC$NewLine     IN VARCHAR2 DEFAULT CHR(10)  -- defaull NL character
  RETURN TYP_TAB_CHAR ;
END Pkg_Tools;
CREATE OR REPLACE PACKAGE BODY Pkg_Tools
IS
  -- fonction de retour du contenu d'une balise XML  --
  FUNCTION Get_Xml_Tag
     PC$XmlContent  IN VARCHAR2,                 -- contenu XML
     PC$Tag         IN VARCHAR2,                 -- tag recherche
     PC$NewLine     IN VARCHAR2 DEFAULT CHR(10)  -- defaull NL character
  RETURN TYP_TAB_CHAR
  IS
   TC$Table      TYP_TAB_CHAR ;
   LC$Ligne      VARCHAR2(32000) ;
   LC$Xml        VARCHAR2(32000) ;
   LN$INDEX      PLS_INTEGER := 0 ;
   LN$TagDeb     PLS_INTEGER ;
   LN$TagFin     PLS_INTEGER ;
   LN$TagLength  PLS_INTEGER ;
   LN$LigLength  PLS_INTEGER ;
   LN$Occur      PLS_INTEGER := 1 ;
  BEGIN
    IF ( PC$XmlContent IS NOT NULL AND PC$Tag IS NOT NULL ) THEN
      LC$Xml := REPLACE( PC$XmlContent, CHR(13), '' ) ;
      LN$TagLength := LENGTH( PC$Tag ) ;
       LOOP
      LN$TagDeb := INSTR( LC$Xml, PC$Tag, 1, LN$Occur ) ;
      LN$TagFin := INSTR( LC$Xml, '</' || SUBSTR(PC$Tag,2, 256), 1, LN$Occur ) ;
      LN$LigLength := (LN$TagFin - ( LN$TagDeb + LN$TagLength ) ) ;
      IF (LN$TagDeb > 0 AND LN$TagFin > 0 ) THEN
         LN$Occur := LN$Occur + 1 ;
         LC$Ligne := SUBSTR( LC$Xml, LN$TagDeb + LN$TagLength, LN$LigLength ) ;
         LOOP
           LN$INDEX := LN$INDEX + 1 ;
           LN$TagDeb := INSTR( LC$Ligne, PC$NewLine ) ;
           IF LN$TagDeb > 0 THEN
             IF Trim( SUBSTR( LC$Ligne, 1, LN$TagDeb - 1 )) IS NOT NULL THEN
               TC$Table(LN$INDEX) := SUBSTR( LC$Ligne, 1, LN$TagDeb - 1 ) ;
             ELSE
               LN$INDEX := LN$INDEX - 1 ;
             END IF ;
             LC$Ligne := SUBSTR( LC$Ligne, LN$Tagdeb + LENGTH( PC$NewLine ), 30000 ) ;
           ELSE
             IF Trim(LC$Ligne) IS NOT NULL THEN
                TC$Table(LN$INDEX) := LC$Ligne ;
             END IF ;
             EXIT ;
           END IF ;
         END LOOP ;
      ELSE
          EXIT ;
      END IF ;
       END LOOP ;
    END IF ;
    RETURN TC$Table ;
  END Get_Xml_Tag ;
END Pkg_Tools;
/Then the call:
DECLARE
   LC$t  VARCHAR2(2000);
   LT$Table Pkg_Tools.TYP_TAB_CHAR ;
BEGIN
   lc$t := '<?xml version="1.0" encoding="UTF-8"?><WSAnswerTO><error>false</error><errorMessage></errorMessage><results>'
||'<CardTypeTO><carTypId>3</carTypId><TYPE>AMERICAN EXPRESS</TYPE><numLength>15</numLength><cvvLength>4</cvvLength>'
||'<comments>1 800-639-0002</comments></CardTypeTO><CardTypeTO><carTypId>4</carTypId><TYPE>DISCOVER</TYPE>'
||'<numLength>16</numLength><cvvLength>3</cvvLength><comments>1 800-347-2683</comments></CardTypeTO>'
||'<CardTypeTO><carTypId>1</carTypId><TYPE>MASTERCARD</TYPE><numLength>16</numLength><cvvLength>3</cvvLength>'
||'<comments>1 800-633-7367</comments></CardTypeTO><CardTypeTO><carTypId>2</carTypId><TYPE>VISA</TYPE>'
||'<numLength>16</numLength><cvvLength>3</cvvLength><comments>1 800-945-2000</comments></CardTypeTO></results></WSAnswerTO>' ;
   LT$Table := Pkg_Tools.Get_Xml_Tag(LC$T,'<TYPE>') ; 
   IF LT$Table.COUNT > 0 THEN
     FOR i IN LT$Table.First .. LT$Table.Last LOOP
        dbms_output.put_line( 'Table(' || i || ')=' || LT$Table(i) ) ;
     END LOOP ;
   ELSE
     dbms_output.put_line( 'tag xml not found' ) ;
   END IF ;
END;Francois