Parser

Kind of class: public class
Package:
Inherits from:
  • none
Classpath: org.asaplibrary.data.xml.Parser
File last modified: Wednesday, 11 May 2011, 18:34:06
Class for parsing XML data into DataValueObject classes. The class provides static functions for calling IParsable.parseXML on newly created objects of a specified type, either for single data blocks or for an array of similar data. The Parser removes the tedious for-loop from the location where the XML data is loaded, and moves the parsing of the XML data to the location where it's used for the first time: the DataValueObject class. Your application can use this data, that contains typed variables, without ever caring about the original source of the data. When the XML structure is changed, only the parsing function in the DataValueObject class has to be changed, thereby facilitating maintenance and development.
Usage
  • Consider an XML file with the following content: 
    <?xml version="1.0" encoding="UTF-8"?>
<settings>
<urls>
<url name="addressform" url="../xml/address.xml" />
<url name="entries" url="../xml/entries.xml" />
</urls>
</settings>
    Once the XML has been loaded, it can be converted into an Array of URLData objects with the following code: 
    // objects of type URLData
private var mURLs:Array;

// parse XML
// @param inXml: XML
// @return true if parsing went ok, otherwise false
private function handleSettingsLoaded (inXml:XML) : Boolean {
var xmlList:XMLList = XMLList(inXml);
mURLs = Parser.parseList(xmlList.urls.url, URLData, false);
return (mURLs != null);
}
    After calling this function, the member variable mURLs contains a list of objects of type URLData, filled with the content of the XML file. Notes to this code:
    • The first parameter to parseList is a (can be a) repeating node where each node contains similar data to be parsed into
    • Conversion of nodes to an Array is not necessary. If the <urls>-node in the aforementioned XML file would contain only one <url>-node, the parser still returns an Array, with one object of type URLData.
    • Since the last parameter to the call to parseList is false, an error in the xml data will result in mURLs being null. The parsing class determines if the data is valid or not, by returning true or false from parseObject().

Summary

Class methods
  • parseList (inList:XMLList, inClass:Class, inIgnoreError:Boolean = false) : Array
    • Parse an XMLList into an array of the specified class instance by calling its parseXML function
  • parseXML (inXML:XML, inClass:Class, inIgnoreError:Boolean = false) : IParsable
    • Parse XML into the specified class instance by calling its parseXML function

Class methods

parseList

static function parseList(inList:XMLList, inClass:Class, inIgnoreError:Boolean = false) : Array

Parse an XMLList into an array of the specified class instance by calling its parseXML function

Parameters
inXMLList :list of XML nodes
inClass :classname to be instanced; class must implement IParsable
ignoreError:if true, the return value of parseXML is always added to the array, and the array itself is returned. Otherwise, an error in parsing will return null.
Returns
  • Array of new objects of the specified type, cast to IParsable, or null if parsing returned false.

parseXML

static function parseXML(inXML:XML, inClass:Class, inIgnoreError:Boolean = false) : IParsable

Parse XML into the specified class instance by calling its parseXML function

Parameters
inXML :XML document or node
inClass :classname to be instanced; class must implement IParsable
ignoreError:if true, the return value of IParsable.parseXML is ignored, and the newly created object is always returned
Returns
  • a new object of the specified type, cast to IParsable, or null if parsing returned false.