OpenEdge Development: Working with XML - Product ...

Reading and Writing XML with the Document Object Model (DOM)
Reading XML input into ABL
2–14
This section describes how to read XML input into ABL.
To read in an XML file and process it:
1. Create an X-document object.
2. Create an X-noderef object to represent your root node.
3. Use the LOAD( ) method to read the input file.
4. Use the GET-DOCUMENT-ELEMENT( ) method to get the root node reference handle.
5. Create an X-noderef object to represent nodes for your document.
6. Using the GET-CHILD( ) method, read through the child nodes.
7. Using the GET-ATTRIBUTE( ) METHOD, the NAME attribute, the NODE-VALUE attribute and
other attributes and methods, access the XML data.
8. Update the database or other fields as necessary.
9. Delete the objects.
Loading an XML file
The LOAD( ) method reads the specified file into memory, parses it, optionally validates it, and
makes its contents available to ABL. Once the XML file is in memory, you must get the handle
to its root element by using the GET-DOCUMENT-ELEMENT( ) method. Once you have the root
node handle, you can manipulate the remaining child nodes.
The following code fragment demonstrates loading an XML file called myfile.xml:
DEFINE VARIABLE hDocMine AS HANDLE NO-UNDO.
DEFINE VARIABLE hRootMine AS HANDLE NO-UNDO.
CREATE X-DOCUMENT hDocMine.
CREATE X-NODEREF hRootMine.
hDocMine:LOAD("FILE","myfile.xml",TRUE).
hDocMine:GET-DOCUMENT-ELEMENT(hRootMine).
. . .
Loading an XML file from a LONGCHAR
An XML file can be read from a LONGCHAR as the following code fragment demonstrates:
DEFINE VARIABLE longstring AS LONGCHAR NO-UNDO.
. . .
hDoc:LOAD("LONGCHAR",longstring,FALSE).
. . .