COBOL Tutorial

COBOL XML-NAMESPACE - Quick Reference

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Overview

XML-NAMESPACE in COBOL refers to the functionality for handling XML namespaces during XML document processing. XML namespaces provide a way to avoid naming conflicts by qualifying element names with Uniform Resource Identifiers (URIs), enabling the processing of complex XML documents with elements from different vocabularies.

Key Features

Namespace awareness - Process XML with namespace support
Prefix handling - Work with namespace prefixes and URIs
Conflict resolution - Avoid naming conflicts between elements
Multi-namespace support - Handle multiple namespaces in one document

Syntax and Usage

XML namespace handling syntax and usage patterns for different XML processing scenarios.

Basic XML Namespace Handling

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. XML-NAMESPACE-EXAMPLE.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  XML-DOCUMENT    PIC X(1000) VALUE
           "
           John Doe
           12345
           ".
       01  XML-EVENT-TYPE  PIC X(20).
       01  XML-EVENT-NAME  PIC X(30).
       01  XML-NAMESPACE-URI PIC X(100).
       01  XML-NAMESPACE-PREFIX PIC X(10).
       01  CUSTOMER-NAME   PIC X(30).
       01  CUSTOMER-ID     PIC 9(5).
       
       PROCEDURE DIVISION.
           XML PARSE XML-DOCUMENT
               PROCESSING PROCEDURE HANDLE-NAMESPACE
               NAMESPACE-PREFIX IS XML-NAMESPACE-PREFIX
               NAMESPACE-URI IS XML-NAMESPACE-URI
           END-XML
           
           DISPLAY "Customer Name: " CUSTOMER-NAME
           DISPLAY "Customer ID: " CUSTOMER-ID
           STOP RUN.
       
       HANDLE-NAMESPACE.
           EVALUATE XML-EVENT-TYPE
               WHEN "START-OF-ELEMENT"
                   IF XML-EVENT-NAME = "name" AND XML-NAMESPACE-PREFIX = "ns"
                       MOVE "Y" TO PROCESSING-NAME
                   END-IF
               WHEN "CHARACTER-CONTENT"
                   IF PROCESSING-NAME = "Y"
                       MOVE XML-EVENT-CONTENT TO CUSTOMER-NAME
                       MOVE "N" TO PROCESSING-NAME
                   END-IF
           END-EVALUATE
           EXIT.

Basic XML namespace handling to process namespaced XML elements.

Multiple Namespace Handling

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. XML-MULTI-NAMESPACE.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  XML-DOCUMENT    PIC X(1000) VALUE
           "
           John Doe
           Widget
           29.99
           ".
       01  XML-EVENT-TYPE  PIC X(20).
       01  XML-EVENT-NAME  PIC X(30).
       01  XML-NAMESPACE-URI PIC X(100).
       01  XML-NAMESPACE-PREFIX PIC X(10).
       01  PROCESSING-FLAGS.
           05  PROCESSING-CUSTOMER PIC X VALUE "N".
           05  PROCESSING-PRODUCT  PIC X VALUE "N".
       01  ORDER-DATA.
           05  CUSTOMER-NAME   PIC X(30).
           05  PRODUCT-ITEM   PIC X(20).
           05  PRODUCT-PRICE  PIC 9(4)V99.
       
       PROCEDURE DIVISION.
           XML PARSE XML-DOCUMENT
               PROCESSING PROCEDURE HANDLE-MULTI-NAMESPACE
           END-XML
           
           DISPLAY "Customer: " CUSTOMER-NAME
           DISPLAY "Product: " PRODUCT-ITEM
           DISPLAY "Price: " PRODUCT-PRICE
           STOP RUN.
       
       HANDLE-MULTI-NAMESPACE.
           EVALUATE XML-EVENT-TYPE
               WHEN "START-OF-ELEMENT"
                   EVALUATE XML-NAMESPACE-PREFIX
                       WHEN "customer"
                           IF XML-EVENT-NAME = "name"
                               MOVE "Y" TO PROCESSING-CUSTOMER
                           END-IF
                       WHEN "product"
                           EVALUATE XML-EVENT-NAME
                               WHEN "item"
                                   MOVE "Y" TO PROCESSING-PRODUCT
                               WHEN "price"
                                   MOVE "Y" TO PROCESSING-PRICE
                           END-EVALUATE
                   END-EVALUATE
               WHEN "CHARACTER-CONTENT"
                   IF PROCESSING-CUSTOMER = "Y"
                       MOVE XML-EVENT-CONTENT TO CUSTOMER-NAME
                       MOVE "N" TO PROCESSING-CUSTOMER
                   END-IF
                   IF PROCESSING-PRODUCT = "Y"
                       MOVE XML-EVENT-CONTENT TO PRODUCT-ITEM
                       MOVE "N" TO PROCESSING-PRODUCT
                   END-IF
           END-EVALUATE
           EXIT.

Handling multiple namespaces in a single XML document.

Default Namespace Handling

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. XML-DEFAULT-NAMESPACE.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  XML-DOCUMENT    PIC X(1000) VALUE
           "
           John Doe
           123 Main St
           ".
       01  XML-EVENT-TYPE  PIC X(20).
       01  XML-EVENT-NAME  PIC X(30).
       01  XML-NAMESPACE-URI PIC X(100).
       01  DEFAULT-NAMESPACE PIC X(100) VALUE "http://example.com/customer".
       01  CUSTOMER-INFO.
           05  CUSTOMER-NAME    PIC X(30).
           05  CUSTOMER-ADDRESS PIC X(50).
       
       PROCEDURE DIVISION.
           XML PARSE XML-DOCUMENT
               PROCESSING PROCEDURE HANDLE-DEFAULT-NAMESPACE
           END-XML
           
           DISPLAY "Name: " CUSTOMER-NAME
           DISPLAY "Address: " CUSTOMER-ADDRESS
           STOP RUN.
       
       HANDLE-DEFAULT-NAMESPACE.
           EVALUATE XML-EVENT-TYPE
               WHEN "START-OF-ELEMENT"
                   IF XML-NAMESPACE-URI = DEFAULT-NAMESPACE
                       EVALUATE XML-EVENT-NAME
                           WHEN "name"
                               MOVE "Y" TO PROCESSING-NAME
                           WHEN "address"
                               MOVE "Y" TO PROCESSING-ADDRESS
                       END-EVALUATE
                   END-IF
               WHEN "CHARACTER-CONTENT"
                   IF PROCESSING-NAME = "Y"
                       MOVE XML-EVENT-CONTENT TO CUSTOMER-NAME
                       MOVE "N" TO PROCESSING-NAME
                   END-IF
                   IF PROCESSING-ADDRESS = "Y"
                       MOVE XML-EVENT-CONTENT TO CUSTOMER-ADDRESS
                       MOVE "N" TO PROCESSING-ADDRESS
                   END-IF
           END-EVALUATE
           EXIT.

Handling default namespaces without explicit prefixes.

Namespace Types

Prefixed Namespaces

Namespaces with explicit prefixes.

xml

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xmlns:prefix="uri"
content

Default Namespaces

Namespaces without explicit prefixes.

xml

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xmlns="uri"
content

Multiple Namespaces

Multiple namespaces in one document.

xml

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xmlns:ns1="uri1" xmlns:ns2="uri2"
content
content

Nested Namespaces

Namespaces with different scopes.

xml

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5

  
    content

Best Practices

Validate namespaces - Always validate namespace URIs and prefixes
Handle conflicts - Be prepared to handle namespace conflicts
Use meaningful prefixes - Choose descriptive namespace prefixes
Document namespace usage - Document which namespaces your program expects
Error handling - Provide error handling for namespace-related issues

XML-NAMESPACE Quick Reference

Namespace Type	Declaration	Usage
Prefixed	xmlns:prefix="uri"	Explicit namespace qualification
Default	xmlns="uri"	Implicit namespace for elements
Multiple	xmlns:ns1="uri1" xmlns:ns2="uri2"	Multiple vocabularies
Nested	Different scopes	Hierarchical namespace structure

Test Your Knowledge

1. What is the primary purpose of XML-NAMESPACE in COBOL?

To generate XML documents
To handle XML namespaces, prefixes, and URI management during XML processing
To validate XML schemas
To format XML output

2. What is an XML namespace?

A file containing XML data
A way to avoid naming conflicts by qualifying element names with URIs
A type of XML attribute
A COBOL data structure

3. How are XML namespaces typically declared?

Using xmlns attributes in XML elements
Using special COBOL statements
Using external configuration files
Using database tables

4. What is the relationship between namespace prefixes and URIs?

They are the same thing
Prefixes are shortcuts that map to full URIs
URIs are shortcuts that map to prefixes
They are completely unrelated

5. How do you handle namespaces in COBOL XML processing?

Using special namespace-aware XML parsing
Using manual string manipulation
Using external tools
Namespaces cannot be handled in COBOL

Frequently Asked Questions

Related Concepts

XML Processing

XML and JSON processing in COBOL.

XML-EVENT

XML parsing events and handling.

XML-INFORMATION

XML information and context.

Data Validation

Validate data structures and formats.

String Operations

String manipulation for XML content.

XML-INFORMATION XML-NNAMESPACE

COBOL Tutorial

COBOL XML-NAMESPACE - Quick Reference

Overview

Key Features

Syntax and Usage

Basic XML Namespace Handling

Multiple Namespace Handling

Default Namespace Handling

Namespace Types

Prefixed Namespaces

Default Namespaces

Multiple Namespaces

Nested Namespaces

Best Practices

XML-NAMESPACE Quick Reference

Test Your Knowledge

Frequently Asked Questions

Is XML-NAMESPACE available in all COBOL compilers?

What are the main components of XML namespace handling?

How do you specify namespace handling in XML PARSE?

Can you process multiple namespaces in one XML document?

What is the difference between default namespaces and prefixed namespaces?

Related Concepts

XML Processing

XML-EVENT

XML-INFORMATION

Data Validation

String Operations

Related Pages