utils

DG.Browser

A namespace with static properties for browser/feature detection.

if (DG.Browser.ie6) {
    alert('Upgrade your browser, dude!');
}

Properties

Property	Type	Description
ie	Boolean	true for all Internet Explorer versions (not Edge).
ielt9	Boolean	true for Internet Explorer versions less than 9.
edge	Boolean	true for the Edge web browser.
webkit	Boolean	true for webkit-based browsers like Chrome and Safari (including mobile versions).
gecko	Boolean	true for gecko-based browsers like Firefox.
android	Boolean	true for any browser running on an Android platform.
android23	Boolean	true for browsers running on Android 2 or Android 3.
chrome	Boolean	true for the Chrome browser.
safari	Boolean	true for the Safari browser.
ie3d	Boolean	true for all Internet Explorer versions supporting CSS transforms.
webkit3d	Boolean	true for webkit-based browsers supporting CSS transforms.
gecko3d	Boolean	true for gecko-based browsers supporting CSS transforms.
opera12	Boolean	true for the Opera browser supporting CSS transforms (version 12 or later).
any3d	Boolean	true for all browsers supporting CSS transforms.
mobile	Boolean	true for all browsers running in a mobile device.
mobileWebkit	Boolean	true for all webkit-based browsers in a mobile device.
mobileWebkit3d	Boolean	true for all webkit-based browsers in a mobile device supporting CSS transforms.
mobileOpera	Boolean	true for the Opera browser in a mobile device.
mobileGecko	Boolean	true for gecko-based browsers running in a mobile device.
touch	Boolean	true for all browsers supporting touch events.
msPointer	Boolean	true for browsers implementing the Microsoft touch events model (notably IE10).
pointer	Boolean	true for all browsers supporting pointer events.
retina	Boolean	true for browsers on a high-resolution "retina" screen.
canvas	Boolean	true when the browser supports <canvas>.
vml	Boolean	true if the browser supports VML.
svg	Boolean	true when the browser supports SVG.

DG.Util

Various utility functions.

Functions

Function	Returns	Description
extend( <Object> dest, <Object> src? )	Object	Merges the properties of the src object (or multiple objects) into dest object and returns the latter. Has an DG.extend shortcut.
create( <Object> proto, <Object> properties? )	Object	Compatibility polyfill for Object.create
bind( <Function> fn, … )	Function	Returns a new function bound to the arguments passed, like Function.prototype.bind. Has a DG.bind() shortcut.
stamp( <Object> obj )	Number	Returns the unique ID of an object, assiging it one if it doesn't have it.
throttle( <Function> fn, <Number> time, <Object> context )	Function	Returns a function which executes function fn with the given scope context (so that the this keyword refers to context inside fn's code). The arguments received by the bound function will be any arguments passed when binding the function, followed by any arguments passed when invoking the bound function. Has an DG.bind shortcut.
wrapNum( <Number> num, <Number[]> range, <Boolean> includeMax? )	Number	Returns the number num modulo range in such a way so it lies within range[0] and range[1]. The returned value will be always smaller than range[1] unless includeMax is set to true.
falseFn()	Function	Returns a function which always returns false.
formatNum( <Number> num, <Number> digits? )	Number	Returns the number num rounded to digits decimals, or to 5 decimals by default.
trim( <String> str )	String	Compatibility polyfill for String.prototype.trim
splitWords( <String> str )	String[]	Trims and splits the string on whitespace and returns the array of parts.
setOptions( <Object: options: Object> obj )	Object	Merges the given properties to the options of the obj object, returning the resulting options. See Class options. Has an DG.setOptions shortcut.
getParamString( <Object> obj, <String> existingUrl?, <Boolean> uppercase? )	String	Converts an object into a parameter URL string, e.g. {a: "foo", b: "bar"} translates to '?a=foo&b=bar'. If existingUrl is set, the parameters will be appended at the end. If uppercase is true, the parameter names will be uppercased (e.g. '?A=foo&B=bar') Simple templating facility, accepts a template string of the form 'Hello {a}, {b}' and a data object like {a: 'foo', b: 'bar'}, returns evaluated string ('Hello foo, bar'). You can also specify functions instead of strings for data values — they will be evaluated passing data as an argument.
isArray(obj)	Boolean	Compatibility polyfill for Array.isArray
indexOf()	Number	Compatibility polyfill for Array.prototype.indexOf
requestAnimFrame( <Function> fn, <Object> context?, <Boolean> immediate? )	requestId: Number	Schedules fn to be executed when the browser repaints. fn is bound to context if given. When immediate is set, fn is called immediately if the browser doesn't have native support for window.requestAnimationFrame, otherwise it's delayed. Returns an id that can be used to cancel the request.
cancelAnimFrame( <Number> id )		Cancels a previous requestAnimFrame. See also window.cancelAnimationFrame.

Properties

Property	Type	Description
lastId	Number	Last unique ID used by stamp()
emptyImageUrl	String	Data URI string containing a base64-encoded empty GIF image. Used as a hack to free memory from unused images on WebKit-powered mobile devices (by setting image src to this string).

DG.LineUtil

Various utility functions for polyine points processing, used by Leaflet internally to make polylines lightning-fast.

Functions

Function	Returns	Description
simplify( <Point[]> points, <Number> tolerance )	Point[]	Dramatically reduces the number of points in a polyline while retaining its shape and returns a new array of simplified points, using the Douglas-Peucker algorithm. Used for a huge performance boost when processing/displaying Leaflet polylines for each zoom level and also reducing visual noise. tolerance affects the amount of simplification (lesser value means higher quality but slower and with more points). Also released as a separated micro-library Simplify.js.
pointToSegmentDistance( <Point> p, <Point> p1, <Point> p2 )	Number	Returns the distance between point p and segment p1 to p2.
closestPointOnSegment( <Point> p, <Point> p1, <Point> p2 )	Number	Returns the closest point from a point p on a segment p1 to p2.

DG.PolyUtil

Various utility functions for polygon geometries.

Functions

Function	Returns	Description
clipPolygon( <Point[]> points, <Bounds> bounds, <Boolean> round? )	Point[]	Clips the polygon geometry defined by the given points by the given bounds (using the Sutherland-Hodgeman algorithm). Used by Leaflet to only show polygon points that are on the screen or near, increasing performance. Note that polygon points needs different algorithm for clipping than polyline, so there's a seperate method for it.