omdOperatorNode

Represents an operator symbol (e.g., +, -, *, ÷) as a leaf node in the expression tree. This node handles the visual representation of operators, including mapping common operation names to their appropriate symbols and applying styling.

Class Definition

export class omdOperatorNode extends omdLeafNode

Constructor

`new omdOperatorNode(nodeData)`

Creates a new omdOperatorNode instance.

nodeData (object | string): The AST node data (from math.js) or the operator symbol as a string (e.g., "+", "*"). The constructor maps common operation names (like "multiply") to their display symbols (like "×"), respecting the configured multiplication symbol.

Public Properties

opName (string): The internal name of the operator (e.g., "*", "+"). This might differ from the displayed symbol for multiplication.
type (string): Always "omdOperatorNode".
textElement (jsvgTextLine): The internal jsvgTextLine instance that displays the operator symbol.

Public Methods

`computeDimensions()`

Calculates the dimensions of the node based on its text content, adding a small amount of padding around the operator symbol to improve visual spacing.

Overrides: omdLeafNode.computeDimensions().

`updateLayout()`

Updates the layout of the node. This method primarily calls the superclass's updateLayout.

Overrides: omdLeafNode.updateLayout().

`toMathJSNode()`

Converts the omdOperatorNode to a math.js-compatible AST format. It creates a minimal OperatorNode AST object.

Returns: object - A math.js-compatible AST node with type: "OperatorNode", op (operator symbol), fn (function name, typically same as op), and an empty args array. The returned object also includes a clone method for compatibility.

`toString()`

Converts the operator node to its string representation, which is simply its opName.

Returns: string - The operator symbol (e.g., "+", "*").

`highlight(color)`

Applies a highlight to the node's background and sets the operator's text color to white for better contrast. This method respects the isExplainHighlighted lock.

color (string): The color of the highlight.

`clearProvenanceHighlights()`

Clears any provenance-related highlights from the node and resets the operator's text color to its default (black).

Internal Methods

parseOpName(nodeData): Extracts the operator's internal name from the constructor's nodeData. It handles mapping from math.js function names (e.g., "multiply") to display symbols (e.g., "×"), using the configured multiplication symbol.
parseType(): Sets the node's type. Always returns "operator".

Example

import { omdOperatorNode } from '@teachinglab/omd';

// Create operator nodes from strings
const plus = new omdOperatorNode('+');
const times = new omdOperatorNode('*'); // Displays as × (configurable via omdConfigManager)

// Create operator node from AST data (e.g., from math.js parse result)
const minus = new omdOperatorNode({
  type: 'OperatorNode',
  op: '-',
  fn: 'subtract'
}); // Displays as −

// To render, typically add to a parent node or an omdDisplay
// node.setFontSize(24);
// node.initialize(); // Computes dimensions and layout

OMD Documentation