Syncfusion Javascript Splitter

Splitter Overview & Key Capabilities

The Splitter is a flexible layout component that:

• Divides containers into multiple panes separated by resizable bars
• Supports horizontal (default) and vertical orientations
• Enables collapsible panes with expand/collapse icons
• Allows flexible sizing in pixels or percentages
• Supports min/max constraints during resizing
• Provides nested splitters for complex layouts
• Includes built-in styling customization via CSS
• Supports RTL for right-to-left languages
• Automatically adjusts panes using flex layout

Documentation and Navigation Guide

API REFERENCE (Complete)

Complete API Reference — This document Comprehensive documentation of ALL components:

• Splitter Properties - All 12 properties with code examples
• Pane Properties - All 8 pane configuration properties
• Methods - All 12 methods with parameters and return types (addEventListener, addPane, appendTo, collapse, dataBind, destroy, expand, getRootElement, refresh, removeEventListener, removePane, Inject)
• Events - All 9 events with argument documentation (created, beforeExpand, expanded, beforeCollapse, collapsed, resizeStart, resizing, resizeStop, beforeSanitizeHtml)
• Event Arguments - Full documentation of all event argument properties

Getting Started

references/getting-started.md

• Package dependencies (@syncfusion/ej2-layouts)
• npm installation and setup
• CSS imports (fluent2.css theme)
• Basic Splitter component initialization
• HTML markup and DOM structure
• Creating panes with child elements

Core Concepts: Panes and Orientation

references/split-panes-orientation.md

• Horizontal layout (default behavior)
• Vertical layout (orientation: 'Vertical' property)
• Orientation API usage
• Pane separators (vertical for horizontal layout, horizontal for vertical)
• Dynamic pane management with addPane() method
• Dynamic pane removal with removePane() method
• Complete examples of both orientations

Pane Configuration & Sizing

references/pane-configuration.md

• Pane sizing in pixel format ('200px', '300px')
• Pane sizing in percentage format ('30%', '50%')
• Auto-sizing with flex layout
• Fixed pane sizes via paneSettings
• Minimum constraints (min property)
• Maximum constraints (max property)
• Flexible last pane behavior

Expand/Collapse Behavior

references/collapse-expand.md

• Enabling collapsible panes (collapsible: true)
• Built-in expand/collapse icons
• User-triggered collapse/expand actions
• Programmatic expand() method for specific pane index
• Programmatic collapse() method for specific pane index
• Specify initial collapsed state (collapsed: true property)
• Event handling and callbacks
• beforeExpand, expanded, beforeCollapse, collapsed events

Pane Content Options

references/pane-content.md

• HTML markup content in panes
• Text content strings
• Inner HTML via child elements
• Dynamic content property
• Loading HTML elements
• Practical content examples

Resizing & Constraints

references/resizing-behavior.md

• Resizing enabled by default
• Resize gripper functionality
• Horizontal vs vertical resizing behavior
• Adjacent pane auto-adjustment during resize
• Min/Max validation constraints
• Preventing resizing (resizable: false)
• Resizable property per pane configuration
• resizeStart, resizing, resizeStop events

Styling & Customization

references/styling-customization.md

• Split bar CSS customization (.e-split-bar)
• Horizontal split bar styling (.e-split-bar-horizontal)
• Vertical split bar styling (.e-split-bar-vertical)
• Hover and active state styling
• Resize handle customization (.e-resize-handler)
• Split bar arrow customization (.e-navigate-arrow)
• Color and theme customization

Complex Layouts & Nesting

references/layouts-nested.md

• Creating nested splitters
• Code editor style layout (horizontal + vertical)
• Outer and inner splitter configuration
• Step-by-step nesting implementation
• Multiple nesting levels
• Complex multi-pane hierarchies

Globalization (RTL)

references/globalization.md

• Right-to-left (RTL) layout support
• enableRtl property configuration
• RTL for Arabic, Hebrew, and other languages
• Default LTR behavior (enableRtl: false)
• RTL styling adjustments

Quick Start Example

import { Splitter } from '@syncfusion/ej2-layouts';

// Initialize Splitter with horizontal orientation (default)
let splitObj: Splitter = new Splitter({
    height: '250px',
    width: '600px',
    paneSettings: [
        { size: '200px', content: 'Pane 1' },
        { size: '200px', content: 'Pane 2' },
        { size: '200px', content: 'Pane 3' }
    ]
});

// Render to DOM
splitObj.appendTo('#splitter');

HTML:

<div id="splitter">
    <div></div>
    <div></div>
    <div></div>
</div>

Common Patterns

Pattern 1: Responsive Panes with Min/Max

let splitObj: Splitter = new Splitter({
    height: '300px',
    width: '100%',
    paneSettings: [
        { size: '30%', min: '20%', max: '50%' },
        { size: '40%', min: '30%', max: '60%' },
        { size: '30%', min: '20%', max: '50%' }
    ]
});
splitObj.appendTo('#splitter');

Pattern 2: Collapsible Panes with Initial State

let splitObj: Splitter = new Splitter({
    height: '300px',
    paneSettings: [
        { collapsible: true, size: '250px', content: 'Sidebar', collapsed: false },
        { collapsible: true, size: '250px', content: 'Details', collapsed: true }
    ]
});
splitObj.appendTo('#splitter');

Pattern 3: Vertical Split (Stacked)

let splitObj: Splitter = new Splitter({
    height: '400px',
    orientation: 'Vertical',
    paneSettings: [
        { size: '150px' },
        { size: '200px' },
        { size: '150px' }
    ]
});
splitObj.appendTo('#splitter');

Pattern 4: Nested Splitters (Code Editor Layout)

// Outer vertical splitter
let verticalSplit: Splitter = new Splitter({
    height: '400px',
    orientation: 'Vertical',
    paneSettings: [
        { size: '250px', min: '30%' }
    ]
});
verticalSplit.appendTo('#verticalSplitter');

// Inner horizontal splitter (inside first pane)
let horizontalSplit: Splitter = new Splitter({
    height: '220px',
    paneSettings: [
        { size: '29%', min: '23%' },
        { size: '20%', min: '15%' },
        { size: '35%', min: '35%' }
    ]
});
horizontalSplit.appendTo('#horizontalSplitter');

Pattern 5: Event Handling - Prevent Collapse

let splitObj: Splitter = new Splitter({
    height: '300px',
    paneSettings: [
        { collapsible: true, size: '250px', content: 'Important Pane' },
        { collapsible: true, size: '250px', content: 'Other Pane' }
    ],
    beforeCollapse: (args: BeforeExpandEventArgs) => {
        // Prevent collapse of first pane
        if (args.index[0] === 0) {
            args.cancel = true;
            console.log('First pane cannot be collapsed');
        }
    }
});
splitObj.appendTo('#splitter');

Pattern 6: Dynamically Add/Remove Panes

let splitObj: Splitter = new Splitter({
    height: '300px',
    paneSettings: [
        { size: '50%', content: 'Pane 1' },
        { size: '50%', content: 'Pane 2' }
    ]
});
splitObj.appendTo('#splitter');

// Add a new pane
document.getElementById('addBtn').addEventListener('click', () => {
    splitObj.addPane({ size: '200px', content: 'New Pane' }, 1);
});

// Remove a pane
document.getElementById('removeBtn').addEventListener('click', () => {
    splitObj.removePane(1);
});

Pattern 7: Programmatic Expand/Collapse

let splitObj: Splitter = new Splitter({
    height: '300px',
    paneSettings: [
        { collapsible: true, size: '250px', content: 'Pane 1', collapsed: true },
        { collapsible: true, size: '250px', content: 'Pane 2' }
    ]
});
splitObj.appendTo('#splitter');

// Expand pane
document.getElementById('expandBtn').addEventListener('click', () => {
    splitObj.expand(0);
});

// Collapse pane
document.getElementById('collapseBtn').addEventListener('click', () => {
    splitObj.collapse(0);
});

Pattern 8: Track Resize Events

let splitObj: Splitter = new Splitter({
    height: '300px',
    paneSettings: [
        { size: '250px', content: 'Pane 1' },
        { size: '250px', content: 'Pane 2' }
    ],
    resizeStart: (args: ResizeEventArgs) => {
        console.log('Resize started on pane:', args.index);
    },
    resizing: (args: ResizingEventArgs) => {
        console.log('Resizing... New sizes:', args.paneSize);
    },
    resizeStop: (args: ResizingEventArgs) => {
        console.log('Resize completed. Final sizes:', args.paneSize);
    }
});
splitObj.appendTo('#splitter');

Pattern 9: Persistent Splitter State

let splitObj: Splitter = new Splitter({
    height: '300px',
    enablePersistence: true, // Save state to localStorage
    paneSettings: [
        { size: '250px', content: 'Pane 1' },
        { size: '250px', content: 'Pane 2' }
    ]
});
splitObj.appendTo('#splitter');
// State automatically persists across page reloads

Pattern 10: RTL Support

let splitObj: Splitter = new Splitter({
    height: '300px',
    enableRtl: true,
    paneSettings: [
        { size: '50%', content: 'محتوى عربي' }, // Arabic content
        { size: '50%', content: 'תוכן עברי' }   // Hebrew content
    ]
});
splitObj.appendTo('#splitter');

Complete API Reference

For detailed examples of all properties, methods, and events, see the Complete API Reference.

Splitter Properties

Complete list of all properties available on the Splitter component:

→ View examples in api-reference.md

Pane Properties

Configuration properties available within each pane in the paneSettings array:

→ View examples in api-reference.md

Methods

→ View examples in api-reference.md

Events & Event Arguments

→ View examples in api-reference.md

Event Arguments

BeforeExpandEventArgs (used in: beforeExpand, beforeCollapse)

• cancel (boolean): Set to true to cancel the action
• element (HTMLElement): Root element
• event (Event): Native event
• index (number[]): Pane index
• pane (HTMLElement[]): Pane elements
• separator (HTMLElement): Separator element

ExpandedEventArgs (used in: expanded, collapsed)

• element (HTMLElement): Root element
• event (Event): Native event
• index (number[]): Pane index
• pane (HTMLElement[]): Pane elements
• separator (HTMLElement): Separator element

ResizeEventArgs (used in: resizeStart)

• cancel (boolean): Set to true to stop resize
• element (HTMLElement): Resizing pane element
• event (Event): Native event
• index (number[]): Pane index
• pane (HTMLElement[]): Pane elements
• separator (HTMLElement): Separator element

ResizingEventArgs (used in: resizing, resizeStop)

• element (HTMLElement): Resizing pane element
• event (Event): Native event
• index (number[]): Pane index
• pane (HTMLElement[]): Pane elements
• paneSize (number[]): Current/final pane size
• separator (HTMLElement): Separator element

BeforeSanitizeHtmlArgs (used in: beforeSanitizeHtml)

• cancel (boolean): Prevent sanitization if needed
• helper (Function): Custom sanitization callback
• selectors (SanitizeSelectors): XSS block list configuration

Quick Reference

Essential Splitter Properties:

• height, width → Container dimensions
• orientation → 'Horizontal' (default) or 'Vertical'
• paneSettings → Array of pane configurations
• enableRtl → Right-to-left support
• separatorSize → Gap width between panes (default: 1px)

Key Pane Properties:

• size → Dimension ('200px' or '30%')
• min / max → Resize constraints
• collapsible → Enable collapse icons (default: false)
• collapsed → Initial state
• resizable → Allow resizing (default: true)
• content → HTML content or text

Common Use Cases

• Dashboard Layout: Sidebar + content with adjustable widths → Use collapsible left pane with flexible right pane
• IDE/Code Editor: Multi-pane editor with nested splitters → File explorer, code editor, console
• Responsive Admin Panel: Collapsible sections with min/max constraints for mobile-friendly resizing
• Multi-Document Interface (MDI): Stack/arrange multiple documents with horizontal and nested vertical splits

Next Steps

1. Start with Getting Started → Setup dependencies and basic initialization
2. Choose your orientation → Horizontal for side-by-side, Vertical for stacked
3. Configure panes → Set sizes, min/max constraints, collapsible behavior
4. Add content → Load HTML markup or text
5. Style as needed → Customize colors, borders, resize handles
6. Add nested splitters → For complex layouts (advanced)

For specific implementation questions, refer to the appropriate reference file in the navigation guide above.