XMLReader Data TypeOfficial Content

It allows XML files or XML strings to be read.

Description

A variable of a data type called XMLReader must be defined in order to read the content of an XML file or XML string from a GeneXus object. The methods and properties needed to obtain the information concerning the nodes that make it up must then be invoked.

The basic idea is that there is a Read() method that behaves like a cursor moving forward through the file, one node at a time. Using some properties such as Name and Value, it is possible to obtain the data for a node, in this case, its name and value. Thus, the Read() method is used to “navigate” through the document in a sequential way, obtaining the information on the different nodes.

Properties

Methods

 

Say we have the following XML document, called Meeting.xml:

<?xml version="1.0" encoding="ISO-8859-1" ?>
<MEETING Date="06/03/01">
  <DATE>06/03/01</DATE>
   <!—Meeting description-->
<! [ CDATA [ Meeting of the application development team.
The meeting was held on Friday, 9.30 a.m. ] ] >
<MEMBERS>
  <MEMBER>Peter</MEMBER>
  <MEMBER>Laura</MEMBER>
  <MEMBER>John</MEMBER>
  <MEMBER>Diana</MEMBER>
  </MEMBERS>
<TASKS>
<TASK>
  <PERSON_IN_CHARGE>Peter</PERSON_IN_CHARGE>
   <! [ CDATA [ Write the application’s documentation ] ] >
  </TASK>
<TASK>
  < PERSON_IN_CHARGE >Diana</ PERSON_IN_CHARGE >
   <! [ CDATA [ Meet with clients ] ] >
  </TASK>
<TASK>
  < PERSON_IN_CHARGE >Laura</ PERSON_IN_CHARGE >
   <! [ CDATA [ Write user’s manual ] ] >
  </TASK>
<TASK>
  < PERSON_IN_CHARGE >John</ PERSON_IN_CHARGE >
   <! [ CDATA [ Document the specifications ] ] >
  </TASK>
  </TASKS>
  </MEETING>

The following GeneXus procedure reads the file and obtains the members attending the meeting:

&XMLReader.Open('Meeting.xml')     
&XMLReader.ReadType(1, 'MEMBERS')
&XMLReader.Read()
    Do While &XMLReader.Name <> 'MEMBERS'
       &MEMBER = &XMLReader.Value
       &XMLReader.Read()                                                             
    Enddo
&XMLReader.Close()
The following GeneXus procedure reads the file and obtains the tasks of a member attending the meeting:
&XMLReader.Open('Meeting.xml') 
&success = &XMLReader.ReadType(1,'PERSON_IN_CHARGE') 
Do While &XMLReader.Value <> &MEMBER 
   &success = &XMLReader.ReadType(1,'PERSON_IN_CHARGE')
   If &success = 0
      Exit
   Endif
Enddo

If &success <> 0
   &XMLReader.Read()
   &tasks = &XMLReader.Value
Else
   &tasks = Nullvalue(&tasks)
Endif
&XMLReader.Close()

Scope

Objects: Procedures, Transactions, Web Panels
Languages: .NET, Java, Ruby (up to GeneXus X Evolution 3), Visual FoxPro (up to GeneXus X Evolution 3)

See Also




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