Util (Utility Functions)

Common utility functions and helper methods for the ge3d library.

Overview

Util is a collection of static utility functions that provide common functionality for data processing, type checking, formatting, and other helper operations throughout the ge3d library.

Usage

import { Util } from 'ge3d';

Type Checking Functions

Function	Parameters	Return Value	Description
isNumber	(obj: any)	boolean	Check if object is a Number type
isString	(obj: any)	boolean	Check if object is a String type
isBoolean	(obj: any)	boolean	Check if object is a Boolean type
isObject	(obj: any)	boolean	Check if object is an Object type
isArray	(obj: any)	boolean	Check if object is an Array type
isSimpleType	(value: any)	boolean	Check if object is a simple type (String, Boolean, Number, Array)
isArrayOfType	(arr: any[], type: any)	boolean	Check if all elements in array are of specific type
hasMethod	(obj: any, methodName: string)	boolean	Check if object has a specific method

String and Number Functions

Function	Parameters	Return Value	Description
formatNum	(num: number, digits?: number)	number	Format number to specified decimal places
getDecimalPlaces	(number: number)	number	Get number of decimal places
trim	(str: string)	string	Remove leading and trailing whitespace
splitWords	(str: string)	string[]	Split string by spaces and return array
padZero	(number: number)	string	Pad number with leading zero if less than 10

Object and Array Functions

Function	Parameters	Return Value	Description
clone	(obj: any, removeKeys?: string[], level?: number)	any	Deep clone object with optional key removal
merge	(dest: object, ...sources: any[])	object	Merge objects deeply
removeArrayItem	(arr: any[], val: any)	boolean	Remove item from array
removeArrayItemReturnArray	(arr: any[], val: any)	any[]	Remove item from array and return array
getArrayRandomOne	(arr: any[])	any	Get random element from array
sortBy	(property: string, isOrder?: boolean)	function	Create sort function for array

File and URL Functions

Function	Parameters	Return Value	Description
getFiletype	(fname: string)	string	Get file type from filename (image, txt, excel, word, pdf, etc.)
getUrlResource	(resource: any, templateValues?: any)	Cesium.Resource	Create Cesium Resource with proxy and headers
serialize	(obj: any)	string	Serialize object to query string

Cesium Integration Functions

Function	Parameters	Return Value	Description
formatPosition	(position: Cesium.Cartesian3)	object	Format Cesium position to readable format
getCesiumValue	(obj: any, ClasName?: any, time?: any)	any	Get final value from Cesium object
getCesiumColor	(color: string, defval?: Cesium.Color)	Cesium.Color	Convert string to Cesium Color
getColorByStyle	(style: object, defval?: Cesium.Color)	Cesium.Color	Get Cesium color from style configuration

Template and HTML Functions

Function	Parameters	Return Value	Description
template	(str: string, data: object, toEmpty?: boolean)	string	Template string replacement with data
getTemplateHtml	(options: object)	string	Generate HTML template for popup/tooltip
getAttrVal	(attr: any, options?: object)	object	Extract simple key-value pairs from Cesium attributes

GeoJSON Functions

Function	Parameters	Return Value	Description
getGeoJsonFeatures	(geojson: object)	object[]	Extract features array from GeoJSON
geoJsonToGraphics	(geojson: any, options?: object)	object[]	Convert GeoJSON to graphic parameters
featureToGraphic	(feature: any, options?: object)	object[]	Convert single GeoJSON feature to graphic

Map and Coordinate Functions

Function	Parameters	Return Value	Description
heightToZoom	(altitude: number)	number	Convert altitude to map zoom level
getHeightByLevel	(level: number)	number	Convert zoom level to altitude
pointsSimplify	(points: any[], options?: object)	LatLngPoint[]	Simplify point array using Turf.js

UI and Visual Functions

Function	Parameters	Return Value	Description
getCircleImage	(count: number, options?: object)	string	Generate circle image for clustering
getSymbolStyle	(symbol: object, attr: object, mergeStyle?: object)	object	Get style from symbol configuration
getCustomShader	(type: number, options?: object)	Cesium.CustomShader	Get custom shader by type

Image Processing Functions

Function	Parameters	Return Value	Description
createImageFromBlob	(blob: Blob)	Promise of Image	Convert Blob to Image
createImageBitmapFromBlob	(blob: ImageBitmapSource)	Promise of HTMLCanvasElement	Convert Blob to ImageBitmap

Performance Functions

Function	Parameters	Return Value	Description
throttle	(func: Function, wait: number)	Function	Throttle function execution
debounce	(func: Function, wait: number)	Function	Debounce function execution

Utility Functions

Function	Parameters	Return Value	Description
uuid	(prefix?: string)	string	Generate unique identifier
getLangText	(key: string, langType?: LangType)	string	Get localized text
handleEval	(fn: string)	any	Safe eval alternative
handAbnormalData	(scene: any, samples: any[], minDeviation?: number, maxDeviation?: number)	any[]	Handle abnormal elevation data
isPCBroswer	()	boolean	Check if running on PC browser
isPCBroswer1	()	boolean	Check if running on PC browser (cached)

Usage Examples

Type Checking

// Check data types
console.log(ge3d.Util.isNumber(123)); // true
console.log(ge3d.Util.isString("hello")); // true
console.log(ge3d.Util.isArray([1, 2, 3])); // true

String and Number Formatting

// Format numbers
const formatted = ge3d.Util.formatNum(3.14159, 2); // 3.14

// Template string replacement
const html = ge3d.Util.template(
  "Name: {name}, Date: {date}", 
  { name: "Ge3D", date: "2024-01-01" }
);

Object Manipulation

// Deep clone object
const cloned = ge3d.Util.clone(originalObject, ['internalId']);

// Merge objects
const merged = ge3d.Util.merge(target, source1, source2);

// Remove array item
const removed = ge3d.Util.removeArrayItem(array, item);

Cesium Integration

// Format Cesium position
const position = Cesium.Cartesian3.fromDegrees(116.3975, 39.9087, 1000);
const formatted = ge3d.Util.formatPosition(position);
// { x: 116.3975, y: 39.9087, z: 1000 }

// Get Cesium color
const color = ge3d.Util.getCesiumColor("#ff0000");

GeoJSON Processing

// Convert GeoJSON to graphics
const graphics = ge3d.Util.geoJsonToGraphics(geojsonData, {
  type: 'point',
  style: { color: '#ff0000' }
});

// Add graphics to layer
graphics.forEach(graphic => {
  layer.addGraphic(graphic);
});

Performance Optimization

// Throttle function
const throttledFunction = ge3d.Util.throttle(expensiveFunction, 100);

// Debounce function
const debouncedFunction = ge3d.Util.debounce(searchFunction, 300);

Notes

1. All Util functions are static and can be called directly without instantiation
2. Many functions are designed to work seamlessly with Cesium objects
3. Type checking functions provide robust validation for different data types
4. Template functions support complex HTML generation for popups and tooltips
5. GeoJSON functions handle coordinate system transformations automatically
6. Performance functions help optimize frequently called operations
7. File type detection supports common image, document, and archive formats