LEDMatrix/docs/widget-guide.md

Widget Development Guide

Overview

The LEDMatrix Widget Registry system allows plugins to use reusable UI components for configuration forms. This enables:

• Reusable Components: Use existing widgets (file upload, checkboxes, etc.) without custom code
• Custom Widgets: Create plugin-specific widgets without modifying the LEDMatrix codebase
• Backwards Compatibility: Existing plugins continue to work without changes

Available Core Widgets

Plugin File Manager Widget (plugin-file-manager)

Full inline file management UI for plugins that manage files via the web_ui_actions system. Renders a card grid, upload zone, create/delete modals, and an entry table editor — entirely inline, no iframe.

plugin_id is automatically injected from template context. File operations call /api/v3/plugins/action immediately on user action; no Save Configuration needed.

Schema Configuration:

{
  "file_manager": {
    "type": "null",
    "title": "Data Files",
    "x-widget": "plugin-file-manager",
    "x-widget-config": {
      "actions": {
        "list":   "list-files",
        "get":    "get-file",
        "save":   "save-file",
        "upload": "upload-file",
        "delete": "delete-file",
        "create": "create-file",
        "toggle": "toggle-category"
      },
      "upload_hint":      "JSON files with day numbers 1–365 as keys",
      "directory_label":  "my_data/",
      "create_fields": [
        { "key": "category_name", "label": "Category Name",
          "placeholder": "e.g., my_words", "pattern": "^[a-z0-9_]+$",
          "hint": "Lowercase letters, numbers, underscores" },
        { "key": "display_name", "label": "Display Name",
          "placeholder": "e.g., My Words", "hint": "Optional" }
      ]
    }
  }
}

Not all 7 actions are required — omit any key to hide the corresponding UI element (e.g., no create = no New File button, no toggle = no enable/disable switch).

The edit view auto-detects whether file content is tabular (object-of-objects with uniform keys) and shows a paginated table editor with inline cells. Otherwise falls back to a JSON textarea.

Used by: of-the-day

---

Time Picker Widget (time-picker)

Single time selection using the browser's native time input. Returns a string in HH:MM (24-hour) format. Generic — works in any plugin without configuration.

Schema Configuration:

{
  "target_time": {
    "type": "string",
    "x-widget": "time-picker",
    "default": "00:00",
    "x-options": {
      "placeholder": "Select time",
      "clearable": true
    }
  }
}

Used by: countdown

---

File Upload Single Widget (file-upload-single)

Single-image upload for string fields. Uploads to the plugin's asset folder (assets/plugins/<plugin_id>/uploads/) and sets the string field value to the returned relative path. Shows a thumbnail preview and a clear button. The plugin_id is automatically injected from the template context — no need to specify it in the schema.

Schema Configuration:

{
  "image_path": {
    "type": "string",
    "x-widget": "file-upload-single",
    "x-upload-config": {
      "allowed_types": ["image/png", "image/jpeg", "image/bmp", "image/gif"],
      "max_size_mb": 5
    }
  }
}

Note: Unlike file-upload (array-level), this widget is for a single string field. It is ideal for per-item images inside array-table rows.

Used by: countdown

---

File Upload Widget (file-upload)

Upload and manage image files with drag-and-drop support, preview, delete, and scheduling.

Schema Configuration:

{
  "type": "array",
  "x-widget": "file-upload",
  "x-upload-config": {
    "plugin_id": "my-plugin",
    "max_files": 10,
    "max_size_mb": 5,
    "allowed_types": ["image/png", "image/jpeg", "image/bmp", "image/gif"]
  }
}

Used by: static-image, news plugins

Checkbox Group Widget (checkbox-group)

Multi-select checkboxes for array fields with enum items.

Schema Configuration:

{
  "type": "array",
  "x-widget": "checkbox-group",
  "items": {
    "type": "string",
    "enum": ["option1", "option2", "option3"]
  },
  "x-options": {
    "labels": {
      "option1": "Option 1 Label",
      "option2": "Option 2 Label"
    }
  }
}

Used by: odds-ticker, news plugins

Custom Feeds Widget (custom-feeds)

Table-based RSS feed editor with logo uploads.

Schema Configuration:

{
  "type": "array",
  "x-widget": "custom-feeds",
  "items": {
    "type": "object",
    "properties": {
      "name": { "type": "string" },
      "url": { "type": "string", "format": "uri" },
      "enabled": { "type": "boolean" },
      "logo": { "type": "object" }
    }
  },
  "maxItems": 50
}

Used by: news plugin (for custom RSS feeds)

Using Existing Widgets

To use an existing widget in your plugin's config_schema.json, simply add the x-widget property:

{
  "properties": {
    "my_images": {
      "type": "array",
      "x-widget": "file-upload",
      "x-upload-config": {
        "plugin_id": "my-plugin",
        "max_files": 5
      }
    },
    "enabled_leagues": {
      "type": "array",
      "x-widget": "checkbox-group",
      "items": {
        "type": "string",
        "enum": ["nfl", "nba", "mlb"]
      },
      "x-options": {
        "labels": {
          "nfl": "NFL",
          "nba": "NBA",
          "mlb": "MLB"
        }
      }
    }
  }
}

The widget will be automatically rendered when the plugin configuration form is loaded.

Creating Custom Widgets

Step 1: Create Widget File

Create a JavaScript file in your plugin directory. The recommended location is widgets/[widget-name].js:

// Ensure LEDMatrixWidgets registry is available
if (typeof window.LEDMatrixWidgets === 'undefined') {
    console.error('LEDMatrixWidgets registry not found');
    return;
}

// Register your widget
window.LEDMatrixWidgets.register('my-custom-widget', {
    name: 'My Custom Widget',
    version: '1.0.0',
    
    /**
     * Render the widget HTML
     * @param {HTMLElement} container - Container element to render into
     * @param {Object} config - Widget configuration from schema
     * @param {*} value - Current value
     * @param {Object} options - Additional options (fieldId, pluginId, etc.)
     */
    render: function(container, config, value, options) {
        const fieldId = options.fieldId || container.id;
        
        // Always escape HTML to prevent XSS
        const escapeHtml = (text) => {
            const div = document.createElement('div');
            div.textContent = text;
            return div.innerHTML;
        };
        
        container.innerHTML = `
            <div class="my-custom-widget">
                <input type="text" 
                       id="${fieldId}_input" 
                       value="${escapeHtml(value || '')}"
                       class="w-full px-3 py-2 border border-gray-300 rounded">
            </div>
        `;
        
        // Attach event listeners
        const input = container.querySelector('input');
        input.addEventListener('change', (e) => {
            this.handlers.onChange(fieldId, e.target.value);
        });
    },
    
    /**
     * Get current value from widget
     */
    getValue: function(fieldId) {
        const input = document.querySelector(`#${fieldId}_input`);
        return input ? input.value : null;
    },
    
    /**
     * Set value programmatically
     */
    setValue: function(fieldId, value) {
        const input = document.querySelector(`#${fieldId}_input`);
        if (input) {
            input.value = value || '';
        }
    },
    
    /**
     * Event handlers
     */
    handlers: {
        onChange: function(fieldId, value) {
            // Trigger form change event
            const event = new CustomEvent('widget-change', {
                detail: { fieldId, value },
                bubbles: true
            });
            document.dispatchEvent(event);
        }
    }
});

Step 2: Reference Widget in Schema

In your plugin's config_schema.json:

{
  "properties": {
    "my_field": {
      "type": "string",
      "description": "My custom field",
      "x-widget": "my-custom-widget",
      "default": ""
    }
  }
}

Step 3: Widget Loading

The widget will be automatically loaded when the plugin configuration form is rendered. The system will:

1. Check if widget is registered in the core registry
2. If not found, attempt to load from plugin directory: /static/plugin-widgets/[plugin-id]/[widget-name].js
3. Render the widget using the registered render function

Note: Currently, widgets are server-side rendered via Jinja2 templates. Custom widgets registered via the registry will have their handlers available, but full client-side rendering is a future enhancement.

Widget API Reference

Widget Definition Object

{
    name: string,           // Human-readable widget name
    version: string,        // Widget version
    render: function,       // Required: Render function
    getValue: function,     // Optional: Get current value
    setValue: function,     // Optional: Set value programmatically
    handlers: object        // Optional: Event handlers
}

Render Function

render(container, config, value, options)

Parameters:

• container (HTMLElement): Container element to render into
• config (Object): Widget configuration from schema
• value (*): Current field value
• options (Object): Additional options
  • fieldId (string): Field ID
  • pluginId (string): Plugin ID
  • fullKey (string): Full field key path

Get Value Function

getValue(fieldId)

Returns: Current widget value

Set Value Function

setValue(fieldId, value)

Parameters:

• fieldId (string): Field ID
• value (*): Value to set

Examples

See web_interface/static/v3/js/widgets/example-color-picker.js for a complete example of a custom color picker widget.

Best Practices

Security

1. Always escape HTML: Use escapeHtml() or textContent to prevent XSS
2. Validate inputs: Validate user input before processing
3. Sanitize values: Clean values before storing

Performance

1. Lazy loading: Load widget scripts only when needed
2. Event delegation: Use event delegation for dynamic content
3. Debounce: Debounce frequent events (e.g., input changes)

Accessibility

1. Labels: Always associate labels with inputs
2. ARIA attributes: Use appropriate ARIA attributes
3. Keyboard navigation: Ensure keyboard accessibility

Troubleshooting

Widget Not Loading

1. Check browser console for errors
2. Verify widget file path is correct
3. Ensure LEDMatrixWidgets.register() is called
4. Check that widget name matches schema x-widget value

Widget Not Rendering

1. Verify render function is defined
2. Check container element exists
3. Ensure widget is registered before form loads
4. Check for JavaScript errors in console

Value Not Saving

1. Ensure widget triggers widget-change event
2. Verify form submission includes widget value
3. Check getValue function returns correct type
4. Verify field name matches schema property

Current Implementation Status

Phase 1 Complete:

• ✅ Widget registry system created
• ✅ Core widgets extracted to separate files
• ✅ Widget handlers available globally (backwards compatible)
• ✅ Plugin widget loading system implemented

Current Behavior:

• Widgets are server-side rendered via Jinja2 templates (existing behavior preserved)
• Widget handlers are registered and available globally
• Custom widgets can be created and registered
• Full client-side rendering is a future enhancement

Backwards Compatibility:

• All existing plugins using widgets continue to work without changes
• Server-side rendering remains the primary method
• Widget registry provides foundation for future enhancements

See Also

• Widget README - Complete widget development guide with examples
• Plugin Development Guide - General plugin development
• Plugin Configuration Guide - Configuration setup