Tc3JsonXmlSampleXmlDomReader

This sample illustrates how an XML document can be processed programmatically based on DOM. The function block FB_XmlDomParser is used as a basis.

Declaration range

PROGRAM MAIN
VAR
  fbXml : FB_XmlDomParser;
  xmlDoc : SXmlNode;
  xmlMachines : SXmlNode;
  xmlMachine1 : SXmlNode;
  xmlMachine2 : SXmlNode;
  xmlIterator : SXmlIterator;
  xmlMachineNode : SXmlNode;
  xmlMachineNodeValue : STRING;
  xmlMachineAttributeRef : SXmlAttribute;
  xmlMachine1Attribute : SXmlAttribute;
  xmlMachine2Attribute : SXmlAttribute;
  sMachine1Name : STRING;
  sMachine2Name : STRING;
  nMachineAttribute : DINT;
  nMachine1Attribute : DINT;
  nMachine2Attribute : DINT;
  sMessageToParse : STRING(255) := '<Machines><Machine Type="1" Test="3">Wilde Nelli</Machine><Machine Type="2">Huber8</Machine></Machines>';
END_VAR

Implementation range

The implementation section shows various options for parsing an XML document.

(* Load XML content *)
xmlDoc := fbXml.ParseDocument(sMessageToParse);

(* Parse XML nodes - Option 1 *)
xmlMachines := fbXml.ChildByName(xmlDoc, 'Machines');
xmlMachine1 := fbXml.ChildByAttribute(xmlMachines, 'Type', '1');
xmlMachine2 := fbXml.ChildByAttributeAndName(xmlMachines, 'Type', '2', 'Machine');

(* Parse XML nodes - Option 2 *)
xmlMachines := fbXml.ChildByName(xmlDoc, 'Machines');
xmlMachineNode := fbXml.Children(xmlMachines, xmlIterator);
WHILE NOT fbXml.IsEnd(xmlIterator) DO
  xmlMachineNode := fbXml.Node(xmlIterator);
  xmlMachineNodeValue := fbXml.NodeText(xmlMachineNode);
  xmlMachineNode := fbXml.Children(xmlMachines, xmlIterator);
END_WHILE

(* Parse XML nodes - Option 3 *)
xmlMachines := fbXml.ChildByName(xmlDoc, 'Machines');
xmlIterator := fbXml.Begin(xmlMachines);
WHILE NOT fbXml.IsEnd(xmlIterator) DO
  xmlMachineNode := fbXml.Node(xmlIterator);
  xmlMachineNodeValue := fbXml.NodeText(xmlMachineNode);
  xmlIterator := fbXml.Next(xmlIterator);
END_WHILE

(* Parse XML attributes - Option 1*)
xmlMachine1Attribute := fbXml.Attribute(xmlMachine1, 'Type');
xmlMachine2Attribute := fbXml.Attribute(xmlMachine2, 'Type');

(* Parse XML attributes - Option 2*)
xmlIterator := fbXml.AttributeBegin(xmlMachine1);
WHILE NOT fbXml.IsEnd(xmlIterator) DO
  xmlMachineAttributeRef := fbXml.AttributeFromIterator(xmlIterator);
  nMachineAttribute := fbXml.AttributeAsInt(xmlMachineAttributeRef);
  xmlIterator := fbXml.Next(xmlIterator);
END_WHILE

(* Retrieve node values *)
sMachine1Name := fbXml.NodeText(xmlMachine1);
sMachine2Name := fbXml.NodeText(xmlMachine2);

(* Retrieve attribute values *)
nMachine1Attribute := fbXml.AttributeAsInt(xmlMachine1Attribute);
nMachine2Attribute := fbXml.AttributeAsInt(xmlMachine2Attribute);