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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.

ts
const xmlParser = new XmlParser(this.onEventCallback);

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

      case ParserEventType.StartElement:

        if (event.attributes) {
          for (const attributeName in 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:
        const significantText = 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.

ts
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 ​

ts
const xmlParser = new XmlParser(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() ​

ts
xmlParser.parse(xmlString: string)

Parses the supplied xml string.

ParserEvent ​

The parser event data object has the following properties.

eventType ​

ts
const eventType: ParserEventType = event.eventType

Returns the type of the parser event. See ParserEventType

position ​

ts
const position: Position = event.position

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

prefix ​

ts
const prefix: Position = event.prefix

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

namespace ​

ts

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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