eXeLearning Package Validator

A client-side inspector, validator, asset explorer, and preview tool for eXeLearning packages (.elpx and legacy .elp).

All processing happens entirely in the browser — no files are uploaded to any server.

Live demo: https://ateeducacion.github.io/elpx-validator/

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Features

Supported Formats

Format	Manifest	Description
Modern .elpx	content.xml (ODE 2.0)	Full validation with deep structural and semantic checks
Legacy .elp	contentv3.xml	Basic metadata extraction with format-appropriate pipeline

The validator auto-detects the format and applies the correct validation pipeline. A badge (Modern ELPX / Legacy ELP) is shown in the results.

Validation Scope

The validator performs layered validation organized into categories:

1. Package / ZIP layer (PKG*)

• Presence of required files: content.xml, content.dtd, index.html
• Recommended directories: html/, content/resources/, theme/, libs/, idevices/
• Path traversal detection (../)
• Absolute path detection
• Suspicious files (.DS_Store, Thumbs.db, executables)
• Duplicate normalized paths (casing conflicts)

2. XML / Schema layer (XML*)

• XML well-formedness
• Root element is <ode>
• Namespace validation (http://www.intef.es/xsd/ode)
• version attribute presence
• DOCTYPE ode SYSTEM "content.dtd" detection
• Expected root child ordering: userPreferences?, odeResources?, odeProperties?, odeNavStructures
• Unknown root child elements

3. Navigation / Structure layer (NAV*)

• Page, block, and component ID presence and uniqueness
• Parent page reference validation (dangling references)
• Page hierarchy cycle detection
• Sibling ordering consistency
• Component containment validation (page/block ID matches)
• Order field numeric validation

4. Metadata layer (META*)

• odeId and odeVersionId format validation (14-digit timestamp + 6 uppercase alphanumeric)
• eXeVersion presence
• Project title (pp_title) presence

5. iDevice layer (IDEV*)

• Type recognition against a registry of 18 known iDevice types from the ELPX specification
• jsonProperties parseability
• htmlView content check
• Type-specific validation:
  • Image iDevices (image-gallery, magnifier): image asset references
  • URL iDevices (external-website): URL presence
  • Download iDevices (download-source-file): isDownload flag consistency

6. Asset layer (ASSET*)

• Complete asset inventory from the ZIP
• Reference extraction from htmlView, jsonProperties, and exported HTML
• {{context_path}} template variable normalization
• Missing asset detection (referenced but not present)
• Orphaned asset detection (present but never referenced)
• Casing mismatch detection
• Path traversal in references

Known iDevice Types

The registry includes these documented types, classified by validation depth:

Type	Group	Validation
text	Content	Deep
image-gallery	Media	Deep
magnifier	Media	Deep
external-website	Embed	Deep
download-source-file	System	Deep
form, matching, sort, classify, guess, checklist, crossword	Activity	Shallow
casestudy, rubric	Content	Shallow
trueorfalse, quick-questions, quick-questions-multiple-choice	Quiz	Shallow
complete	Activity	Shallow

Unknown/custom iDevice types are reported as informational findings, not errors.

Asset Explorer

The Assets tab provides:

• Full inventory of all files in the package with MIME type, extension, and preview capability
• Filtering: All / Referenced / Orphaned / Missing
• Summary counts: total, referenced, missing, orphaned

Preview System

The Preview tab provides:

• Sandboxed <iframe> preview of index.html and pages under html/
• Asset references rewritten to Blob URLs for offline rendering
• Page selector dropdown

User Interface

The redesigned UI is organized as a navigable inspector:

Tab	Content
Overview	Legacy checklist, package metadata, file size
Findings	All validation findings with severity/category filtering
Pages	Hierarchical page tree with blocks and components
iDevices	Type summary, counts, known/unknown classification
Assets	Full asset inventory with filtering
Preview	Sandboxed page preview

Each finding includes:

• Rule code (e.g., PKG001, XML004, NAV012, IDEV007, ASSET015)
• Severity: error / warning / info
• Category: package / xml / navigation / metadata / idevice / asset / compatibility
• Detailed explanation
• Location (page, block, iDevice)
• Evidence (raw data supporting the finding)
• Repair suggestion

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Validation Rule Catalog

Code Range	Category	Examples
PKG001–PKG014	Package	Missing files, path traversal, suspicious names
XML001–XML008	XML/Schema	Malformed XML, wrong root, namespace, ordering
NAV001–NAV022	Navigation	Missing IDs, duplicates, cycles, containment
META001–META006	Metadata	Missing/invalid odeId, odeVersionId, title
IDEV001–IDEV006	iDevice	Unknown types, parse errors, missing assets/URLs
ASSET001–ASSET005	Asset	Missing, orphaned, path traversal, casing
COMPAT001–COMPAT002	Compatibility	Legacy/modern format detection

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Getting Started

1. Open index.html in a modern browser. No build step is required.
2. Drop an .elp, .elpx, or .zip file onto the drop zone or click it to choose a file.
3. Review the validation results across the different tabs.

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Architecture

The codebase follows a modular architecture:

index.html                    # Application shell
styles.css                    # Styling for the UI
js/
├── core/
│   ├── rules.js              # Rule catalog and finding factory
│   └── model.js              # Normalized project model builder
├── registries/
│   └── idevice-types.js      # Known iDevice type registry
├── validators/
│   ├── package-rules.js      # ZIP/package structure validation
│   ├── xml-rules.js          # XML schema validation
│   ├── nav-rules.js          # Navigation/ID/reference validation
│   ├── idevice-rules.js      # iDevice type validation
│   └── asset-rules.js        # Asset inventory and validation
├── preview/
│   └── virtual-fs.js         # Blob URL virtual filesystem
├── validator.js              # Main orchestrator (new + legacy API)
└── app.js                    # UI layer
tests/                        # Jest unit tests

All validation rules return structured finding objects:

{
  code: 'IDEV001',
  severity: 'info',
  category: 'idevice',
  message: 'Unknown iDevice type',
  details: 'The component uses an iDevice type not in the known registry.',
  location: { pageId: '...', blockId: '...', ideviceId: '...' },
  evidence: { odeIdeviceTypeName: '...' },
  suggestion: 'Verify whether this is a custom iDevice or a typo.'
}

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Development

Requirements

• A modern browser (Chrome, Firefox, Safari, Edge)
• Node.js (for running tests)

Running locally

Open index.html in a browser, or start a local HTTP server:

npm run start

By default it listens on http://localhost:8081.

Running tests

npm install
npm test

The test suite includes 102 tests covering:

• Rule catalog and finding factory
• Project model builder
• iDevice type registry
• Package-level validation (path traversal, suspicious files, duplicates)
• XML/schema validation (namespace, version, DOCTYPE, ordering)
• Navigation validation (ID uniqueness, cycles, cross-references, ordering)
• iDevice validation (type recognition, JSON parsing, type-specific checks)
• Asset validation (inventory, references, orphans, missing, casing)
• Legacy API backward compatibility

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Known Limitations

• DTD validation: True DTD validation is not feasible in the browser. The tool checks for the DOCTYPE declaration and content.dtd presence but does not validate XML against the DTD.
• Legacy .elp: Limited to metadata extraction. Deep structural validation requires the modern content.xml format.
• Preview fidelity: HTML preview uses Blob URLs for assets, which may not perfectly replicate server-side behavior for all resource types.
• iDevice depth: Only a subset of iDevice types have deep validation. Custom iDevices are flagged as informational only.
• Cross-check: XML vs. exported HTML cross-checking is reference-based only; full structural comparison is a future enhancement.

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Credits

Built by the Área de Tecnología Educativa – Gobierno de Canarias.

References:

• eXeLearning
• ELPX Format Specification