XmlParser

The XMLParser provides the ability to parse and extract data from XML documents.

Using XmlParser ​

To parse an xml document, first institiate the class with the ParserEvent handler.

constxmlParser=newXmlParser(this.onEventCallback);

onEventCallback(event: ParserEvent) {
switch (event.eventType) {

case ParserEventType.StartElement:

if (event.attributes) {
for (constattributeNamein event.attributes) {
if (event.attributes.hasOwnProperty(attributeName)) {
 console.log({
 eventType: event.eventType,
 elementName: event.elementName,
 attributeName: attributeName,
 result: event.attributes[attributeName],
 significantText: null,
 });
 }
 }
 } else {
 console.log({
 eventType: event.eventType,
 elementName: event.elementName,
 attributeName: null,
 result: null,
 significantText: null,
 });
 }
break;
case ParserEventType.EndElement:

 console.log({
 eventType: event.eventType,
 elementName: event.elementName,
 attributeName: null,
 result: null,
 significantText: null,
 });
break;

case ParserEventType.Text:
constsignificantText= event.data.trim();

if (significantText !=='') {
 console.log({
 eventType: event.eventType,
 elementName: null,
 attributeName: null,
 result: null,
 significantText: significantText,
 });
 }
break;
default:
break;
 }
 }

Then call the parse method on the instance passing it the data to be parsed.

xmlParser.parse(`
 <Document>
 <First attr1=\ "attribute1\" attr2=\ "attribute2\">I am first</First>
 <Second>I am second</Second>
 <Third>
 <FirstChild attr3=\ "attribute3\"></FirstChild>
 </Third>
 </Document>
`)

XmlParser API ​

constructor ​

constxmlParser=newXmlParser(onEvent: (event:ParserEvent) =>void, onError?: (error:Error, position:Position) =>void, processNamespaces?: boolean, angularSyntax?: boolean)

Creates a new instance of the XmlParser class.

• onEvent is the callback to execute when a parser event occurs.

• Optional: onError is the callback to execute when a parser error occurs. The error parameter contains the error and the position represents the position of the parsing error.

• Optional: processNamespaces specifies whether namespaces should be processed.

parse() ​

xmlParser.parse(xmlString: string)

Parses the supplied xml string.

ParserEvent ​

The parser event data object has the following properties.

eventType ​

consteventType:ParserEventType= event.eventType

Returns the type of the parser event. See ParserEventType

position ​

constposition:Position= event.position

Returns the position (column number and line number) in the xml string where the event was generated.

prefix ​

constprefix:Position= event.prefix

If namespace processing is enabled, returns the prefix of the element if the eventType is ParserEventType.StartElement or ParserEventType.EndElement.

namespace ​

If namespace processing is enabled, returns the namespace of the element if the eventType is ParserEventType.StartElement or ParserEventType.EndElement.

elementName ​

Returns the name of the element if the eventType is ParserEventType.StartElement or ParserEventType.EndElement.

attributes ​

Returns a JSON object with the attributes of an element if the eventType is ParserEventType.StartElement.

data ​

Returns the relevant data if the eventType is ParserEventType.Text, ParserEventType.CDATA or ParserEventType.Comment.

toString() ​

Returns a JSON string representation of this instance.

ParserEventType ​

The following are the available parser event types:

StartElement ​

Specifies the StartElement event type.

EndElement ​

Specifies the EndElement event type.

ParserEventType.Text ​

Specifies the Text event type.

ParserEventType.CDATA ​

Specifies the CDATA event type.

ParserEventType.Comment ​

Specifies the Comment event type.

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