Comparison of XPCML source to PCML source

PCML allows you to use the init attribute of the <data> tag to specify the initial value for a data element in the PCML source. However, using PCML to specify values has the following limitations:

• You cannot use the init attribute to set array values
• Validation of the init value occurs only after parsing the PCML document

To specify array values in PCML, you must first read in and parse the PCML document, then perform a series of calls to ProgramCallDocument.setValue().

Using XPCML makes it easier to specify values of single elements and arrays:

• Specify values for both scalar and array elements in the XPCML source file
• Validate the specified array values at parse time

The following simple comparisons indicate ways in which XPCML differs from PCML. Each example defines a program call for an iSeries™ server program.

Example: Calling an iSeries server program

The following examples call an iSeries server program called prog1.

XPCML source code

    <?xml version="1.0" encoding="UTF-8"?>
    <xpcml xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
         xsi:noNamespaceSchemaLocation='xpcml.xsd' version="4.0">
        <program name="prog1" path="/QSYS.LIB/W95LIB.LIB/PROG1.PGM"> 
          <parameterList>
             <stringParm name="parm1"  passDirection="in" length="10">Parm1</stringParm>
             <intParm    name="parm2"  passDirection="in">5</intParm>
             <shortParm  name="parm3"  passDirection="in">3</shortParm>
          </parameterList>
        </program>
    </xpcml>

PCML source code

    <pcml version="4.0">
      <program name="prog1" path="QSYS.LIB/MYLIB.LIB/PROG1.PGM">
         <data name="parm1"  type="char" usage="input" length="10" init="Parm1"/>
         <data name="parm2"  type="int"  usage="input" length="4"  init="5"/>
         <data name="parm3"  type="int"  usage="input" length="2"  precision="16" init="3"/>
      </program>
    </pcml>

Example: Calling an iSeries server program using an array of string parameters

The following examples call an iSeries server program called prog2 and define parm1 as an array of string parameters. Note the functionality of XPCML:

• Initializes the value of each element in the array
• Specifies the input values as element content that a fully validating XML parser can verify

You can take advantage of this XPCML functionality without writing any Java™ code.

PCML cannot match the XPCML performance. PCML cannot initialize the value of each element in the array. PCML cannot validate the init values at parse time. To match the functionality of XPCML, you would have to read in and parse the PCML document, then code your Java application to set the value for each array element. You would also have to write code to validate the parameters.

XPCML source code

    <?xml version="1.0" encoding="UTF-8"?>
    <xpcml xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
         xsi:noNamespaceSchemaLocation="xpcml.xsd" version="4.0">

        <program name="prog2" path="/QSYS.LIB/W95LIB.LIB/PROG2.PGM"> 
          <parameterList>
             <arrayOfStringParm name="parm1" passDirection="in"
                length="10" count="3">
                 <i>Parm1-First value</i>
                 <i>Parm1-Second value</i>
                 <i>Parm1-Third value</i>
             </arrayOfStringParm>
             <longParm name="parm2"  passDirection="in">5</longParm>
             <zonedDecimalParm name="parm3"  passDirection="in"
                totalDigits="5" fractionDigits="2">32.56</zonedDecimalParm>
          </parameterList>
        </program>
    </xpcml>

PCML source code

    <pcml version="4.0">
      <program name="prog2" path="QSYS.LIB/MYLIB.LIB/PROG2.PGM">
         <data name="parm1"  type="char"  usage="input" length="20" count="3"/>
         <data name="parm2"  type="int"   usage="input" length="8"  init="5"/>
         <data name="parm3"  type="zoned" usage="input" length="5"  precision="2" init="32.56"/>
      </program>
    </pcml>