contentv3.xml Format Documentation

See also: For the modern .elpx format and content.xml structure, see ELPX Format Documentation.

This document describes the legacy contentv3.xml format used by eXeLearning 2.x (eXe Legacy). This format is a Python object serialization to XML and is not suitable for DTD validation due to its dynamic structure.

Overview

The contentv3.xml format is a serialization of Python objects from the original eXeLearning application. It uses a reference-based system to represent complex object graphs.

Important: A DTD cannot effectively validate this format because: 1. Class names are attribute values, not element names 2. Cross-references between objects cannot be validated with DTD 3. The structure is highly dynamic

Root Structure

<?xml version="1.0" encoding="utf-8"?>
<instance xmlns="http://www.exelearning.org/content/v0.3"
          reference="2"
          version="0.3"
          class="exe.engine.package.Package">
  <dictionary>
    <!-- Package metadata and content -->
  </dictionary>
</instance>

Root Attributes

Attribute	Description
xmlns	Namespace: http://www.exelearning.org/content/v0.3
reference	Unique numeric ID for this object
version	Format version (typically "0.3")
class	Python class name (exe.engine.package.Package)

Data Types

String Elements

<string role="key" value="_title"/>

Used for dictionary keys and simple string values.

Unicode Elements

<unicode value="Document Title"/>
<unicode content="true" value="&lt;p&gt;HTML content&lt;/p&gt;"/>

Attribute	Description
value	The text content
content	If "true", indicates HTML content

Boolean Elements

<boolean value="True"/>
<boolean value="False"/>

Integer Elements

<int value="42"/>

None/Null Elements

<none/>

Reference Elements

<reference key="4"/>

References another object by its reference ID.

Dictionary Elements

<dictionary>
  <string role="key" value="propertyName"/>
  <unicode value="propertyValue"/>
  <!-- More key-value pairs -->
</dictionary>

Dictionaries contain alternating key-value pairs. Keys are typically <string role="key"> elements.

List Elements

<list>
  <instance class="...">...</instance>
  <instance class="...">...</instance>
</list>

Tuple Elements

<tuple>
  <string value="fieldName"/>
  <list>...</list>
</tuple>

Package Structure

The Package object (exe.engine.package.Package) contains:

Metadata Properties

Key	Type	Description
_title	unicode	Project title
_author	unicode	Author name
_description	unicode	Project description
_lang	unicode	Language code (e.g., "es", "en")
_name	unicode	Project filesystem name
_docType	unicode	Export format ("HTML5")
_isTemplate	boolean	Whether this is a template
_isChanged	boolean	Modified flag
_nextNodeId	int	Next available node ID
_nextIdeviceId	int	Next available iDevice ID

Export Options

Key	Type	Description
_addPagination	boolean	Add page numbers
_addSearchBox	boolean	Include search
_addExeLink	boolean	Include eXe link
_extraHeadContent	unicode	Custom CSS/JS

Navigation Structure

Key	Type	Description
_nodeIdDict	dictionary	Maps node IDs to Node instances
_levelNames	list	Custom hierarchy level names
_root	reference	Root Node reference

Node Structure (Pages)

Nodes represent pages in the navigation hierarchy.

<instance class="exe.engine.node.Node" reference="4">
  <dictionary>
    <string role="key" value="_title"/>
    <unicode value="Page Title"/>

    <string role="key" value="parent"/>
    <reference key="2"/>  <!-- or <none/> for root -->

    <string role="key" value="idevices"/>
    <list>
      <!-- iDevice instances -->
    </list>

    <string role="key" value="children"/>
    <list>
      <!-- Child Node instances -->
    </list>
  </dictionary>
</instance>

Node Properties

Key	Type	Description
_title	unicode	Page title
parent	reference/none	Parent node (none for root)
idevices	list	List of iDevice instances
children	list	Child node instances

iDevice Structure (Components)

iDevices are interactive learning elements. There are multiple types:

JsIdevice (Modern JSON-based)

<instance class="exe.engine.jsidevice.JsIdevice" reference="5">
  <dictionary>
    <string role="key" value="_title"/>
    <unicode value="Activity Title"/>

    <string role="key" value="class_"/>
    <unicode value="text"/>

    <string role="key" value="fields"/>
    <list>
      <!-- Field instances -->
    </list>
  </dictionary>
</instance>

TextAreaField (Content Field)

<instance class="exe.engine.field.TextAreaField" reference="6">
  <dictionary>
    <string role="key" value="_id"/>
    <unicode value="field-id-123"/>

    <string role="key" value="content_w_resourcePaths"/>
    <unicode content="true" value="&lt;p&gt;HTML content&lt;/p&gt;"/>
  </dictionary>
</instance>

Legacy iDevice Types

The following are common legacy iDevice class names:

Text-based iDevices

• FreeTextIdevice - Free text content
• FreeTextfpdIdevice - FPD variant
• GenericIdevice - Generic content
• ReflectionIdevice - Reflection activity
• WikipediaIdevice - Wikipedia content

Interactive iDevices

• TrueFalseIdevice - True/False questions
• MultichoiceIdevice - Multiple choice
• MultiSelectIdevice - Multiple selection
• ClozeIdevice - Fill in the blanks
• QuizTestIdevice - Quiz

Media iDevices

• GalleryIdevice - Image gallery
• ImageMagnifierIdevice - Image magnifier
• AppletIdevice - Java applet (legacy)

Spanish FPD Variants

• VerdaderofalsofpdIdevice
• EleccionmultiplefpdIdevice
• SeleccionmultiplefpdIdevice
• ClozefpdIdevice
• ReflectionfpdIdevice
• TareasIdevice
• ListaApartadosIdevice
• ComillasIdevice
• NotaInformacionIdevice
• CasopracticofpdIdevice
• DebesconocerfpdIdevice
• DestacadofpdIdevice
• ParasabermasfpdIdevice
• And more...

Resource References

Assets are referenced within content using the path format:

resources/image.jpg

The parser extracts these paths using regex pattern /resources\/[^\s"'<>]+/g.

Parsing Strategy

When parsing contentv3.xml:

1. Build Reference Map: Create a map of reference IDs to XML elements
2. Find Package: Locate the root exe.engine.package.Package instance
3. Extract Metadata: Parse the Package dictionary for metadata
4. Find Root Node: Follow the _root reference to the root Node
5. Build Page Tree: Recursively parse nodes and their children
6. Extract iDevices: Parse iDevice instances within each node
7. Map Types: Convert legacy iDevice types to modern equivalents
8. Collect Resources: Extract resource paths from content

Type Mappings

Legacy iDevice types are mapped to modern ODE types:

Legacy Type	Modern Type
FreeTextIdevice	text
TrueFalseIdevice	trueorfalse
MultichoiceIdevice	quick-questions-multiple-choice
MultiSelectIdevice	quick-questions-multiple-choice
ClozeIdevice	complete
ImageMagnifierIdevice	magnifier
GalleryIdevice	image-gallery
CasestudyIdevice	casestudy
FileAttachIdevice	text
AttachmentIdevice	text
ExternalUrlIdevice	external-website
QuizTestIdevice	quick-questions
JsIdevice	Uses class_ attribute

Implementation Files

The contentv3.xml parser is implemented in:

• src/services/xml/legacy-xml-parser.ts - Main parser
• src/services/xml/xml-parser.ts - Format detection
• src/services/xml/interfaces.ts - Type definitions

Example Document

<?xml version="1.0" encoding="utf-8"?>
<instance xmlns="http://www.exelearning.org/content/v0.3"
          reference="1" version="0.3"
          class="exe.engine.package.Package">
  <dictionary>
    <string role="key" value="_title"/>
    <unicode value="My Learning Content"/>

    <string role="key" value="_author"/>
    <unicode value="John Doe"/>

    <string role="key" value="_lang"/>
    <unicode value="en"/>

    <string role="key" value="_root"/>
    <instance class="exe.engine.node.Node" reference="2">
      <dictionary>
        <string role="key" value="_title"/>
        <unicode value="Home"/>

        <string role="key" value="parent"/>
        <none/>

        <string role="key" value="idevices"/>
        <list>
          <instance class="exe.engine.idevice.FreeTextIdevice" reference="3">
            <dictionary>
              <string role="key" value="_title"/>
              <unicode value="Introduction"/>

              <string role="key" value="fields"/>
              <list>
                <instance class="exe.engine.field.TextAreaField" reference="4">
                  <dictionary>
                    <string role="key" value="content_w_resourcePaths"/>
                    <unicode content="true" value="&lt;p&gt;Welcome!&lt;/p&gt;"/>
                  </dictionary>
                </instance>
              </list>
            </dictionary>
          </instance>
        </list>

        <string role="key" value="children"/>
        <list/>
      </dictionary>
    </instance>

    <string role="key" value="_nodeIdDict"/>
    <dictionary>
      <string role="key" value="0"/>
      <reference key="2"/>
    </dictionary>
  </dictionary>
</instance>

Differences from ODE Format

Aspect	contentv3.xml	ODE Format
Root Element	<instance class="...">	<ode>
Serialization	Python objects	Native XML
References	@reference attribute	odePageId, odeBlockId
Content	<unicode content="true">	<htmlView>, <jsonProperties>
Hierarchy	Nested Node instances	Flat with odeParentPageId
Metadata	Dictionary keys	<odeProperty> elements

For full documentation of the ODE format, see elpx-format.md.