kotlin-xml

Kotlin XML project contains:

• XML Model: for manipulation of XML data structures.
• XML Generator: for generation of XML documents out of Kotlin objects using automatic inference.
• XML Editor: a GUI application for operations on XML Model, which can be extended via plugins.

XML Model

The XML Model consists of the following classes:

• XmlDocument: represents an XML Document, contains a root XmlEntity and a method for serialization of the document to text.
• XmlNode: abstract class reprsenting an XML Node, can be an XmlEntity or XmlText.
• XmlEntity: represents an XML Entity, contains a name, a list of attributes in format of key-value and a list of nested XmlNodes.
• XmlText: represents an XML text node, contains a String type value.
• XmlVisitor: an interface for traversal of the XML data structure, is passed to a XmlNode by the accept method.

Usage example:

        val root = XmlEntity("root")
        root.appendAttribute("attributeName", "attributeValue")
        val childEntity = XmlEntity("childEntity")
        val textNode = XmlText("This is a text node.")
        childEntity.appendChild(textNode)
        root.appendChild(childEntity)
        val emptyEntity = XmlEntity("emptyEntity")
        root.appendChild(emptyEntity)
        val document = XmlDocument(root)
        println(document.serialize())

Would produce the following output:

<?xml version="1.0" ?>
<root attributeName="attributeValue">
    <childEntity>This is a text node.</childEntity>
    <emptyEntity/>
</root>"

XML Generator

The XML Genearator is a static class providing functions for automatic XML inference and the following annotations:

• XmlName: to set a specific name of the object in the resulting XML Model.
• XmlAttribute: to indicate that a property should be represented as an attribute (the default is as an entity).
• XmlString: to indicate that a class should be represented as a XmlText node (by calling toString on the object).
• XmlIngnore: to indicate that a property should not be included in the XML Model.

Usage example:

internal data class Course(
    @XmlAttribute
    val name: String,
    @XmlAttribute
    val type: String,
    @XmlAttribute
    val year: Int
)

internal data class Student(
    @XmlAttribute
    val number: Int,
    @XmlAttribute
    val name: String,
    val courses: MutableList<Course>
)

internal fun main() {

    val course = Course(
        "Telecommunications and Computer Engineering",
        "MSc",
        2022
    )
    val student = Student(
        73132,
        "Oleh Petryna",
        mutableListOf(course)
    )

    val xmlStudent = XmlDocument(XmlGenerator.generate(student))
    println(xmlStudent.serialize())
}

Would produce the following output:

<?xml version="1.0" ?>
<Student name="Oleh Petryna" number="73132">
	<courses>
		<Course name="Telecommunications and Computer Engineering" type="MSc" year="2022"/>
	</courses>
</Student>

XML Editor

The XML Editor provides two interfaces for implementing plugins:

• EntityComponent.Action: for implementing custom context-menu actions on XML Entities. Has a lateinit var EntityComponent which will be instantiated with the EntityComponent on which the plugin will perform operations. Must implement execute() and undo() methods and override the name attribute.
• AttributesComponent.AttributeViewTemplate: for implementing custom views on XML Attributes. Must implement a create(name: String, value: String) function which returns a AttributesComponent.AttributeViewTemplate.AttributeView object which must contain a val component: JComponent property and a updateValue(value: String) method.

Check an example implementation at kotlin-xml/src/test/kotlin/org/opetryna/xmleditor/XmlEditorPluginsExample.kt