XML

XML Module in Vint

The XML module in Vint provides basic XML processing capabilities including validation, value extraction, and character escaping/unescaping. This module helps you work with XML data safely and efficiently.

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Importing the XML Module

To use the XML module, simply import it:

import xml

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Functions and Examples

1. Validate XML (validate)

The validate function checks if a given XML string is well-formed and valid.

Syntax:

validate(xmlString)

Example:

import xml

print("=== XML Validation Example ===")

// Valid XML
valid_xml = "<root><name>John</name><age>30</age></root>"
is_valid = xml.validate(valid_xml)
print("Valid XML:", is_valid)
// Output: Valid XML: true

// Invalid XML
invalid_xml = "<root><name>John</age></root>"
is_invalid = xml.validate(invalid_xml)
print("Invalid XML:", is_invalid)
// Output: Invalid XML: false

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2. Extract Value from XML Tag (extract)

The extract function extracts the value from a specific XML tag.

Syntax:

extract(xmlString, tagName)

Example:

import xml

print("=== XML Value Extraction Example ===")
xml_data = "<user><name>John Doe</name><email>john@example.com</email></user>"

name = xml.extract(xml_data, "name")
email = xml.extract(xml_data, "email")

print("Name:", name)
print("Email:", email)
// Output: 
// Name: John Doe
// Email: john@example.com

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3. Escape XML Characters (escape)

The escape function escapes special XML characters to make text safe for XML content.

Syntax:

escape(text)

Example:

import xml

print("=== XML Escape Example ===")
unsafe_text = "<script>alert('Hello & Goodbye');</script>"
safe_text = xml.escape(unsafe_text)

print("Original:", unsafe_text)
print("Escaped: ", safe_text)
// Output: Escaped: &lt;script&gt;alert(&#39;Hello &amp; Goodbye&#39;);&lt;/script&gt;

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4. Unescape XML Entities (unescape)

The unescape function converts XML entities back to their original characters.

Syntax:

unescape(escapedText)

Example:

import xml

print("=== XML Unescape Example ===")
escaped_text = "<tag>Hello & Goodbye</tag>"
unescaped_text = xml.unescape(escaped_text)

print("Escaped:  ", escaped_text)
print("Unescaped:", unescaped_text)
// Output: Unescaped: <tag>Hello & Goodbye</tag>

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Complete Usage Example

import xml

print("=== XML Module Complete Example ===")

// Create XML data
user_name = "John & Jane"
user_email = "user@example.com"

// Escape data for safe XML insertion
safe_name = xml.escape(user_name)
safe_email = xml.escape(user_email)

// Build XML string
xml_string = "<user><name>" + safe_name + "</name><email>" + safe_email + "</email></user>"
print("Generated XML:", xml_string)

// Validate the XML
if xml.validate(xml_string) {
    print("XML is valid!")
    
    // Extract values
    extracted_name = xml.extract(xml_string, "name")
    extracted_email = xml.extract(xml_string, "email")
    
    // Unescape extracted values
    final_name = xml.unescape(extracted_name)
    final_email = xml.unescape(extracted_email)
    
    print("Final Name:", final_name)
    print("Final Email:", final_email)
} else {
    print("Generated XML is invalid!")
}

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Use Cases

• XML Document Processing: Parse and extract data from XML files
• Web Scraping: Extract information from XML responses
• Configuration Files: Read XML configuration data
• Data Exchange: Safely prepare data for XML transmission
• Template Processing: Build XML documents dynamically

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Summary of Functions

Function	Description	Return Type
validate	Validates XML structure and syntax	Boolean
extract	Extracts value from a specific XML tag	String
escape	Escapes special characters for safe XML content	String
unescape	Converts XML entities back to original characters	String

The XML module provides essential functionality for working with XML data safely and efficiently in VintLang applications.