What is this ?

This project is an extension to the original leader-line project https://github.com/anseki/leader-line v1.0.7.

Why using it ?

The original LeaderLine class lacks:

Feature	Description
parent option	The original leaderline class always inserts the line svg element in body. In some cases, inserting the line in a specific element is required.
element property	The LeaderLine instance lacks the element property, that points to the line's svg element in the DOM
scroll positioning	If you create a line using the original class and then drag one of its connected elements (start/end) to the end of its parent's offset, causing the parent to become scrollable, the positioning of the line becomes incorrect
absolute positioning	When you create a line and append it to a draggable element, making the draggable element the parent node of the line SVG element in the DOM, the positioning of the line becomes incorrect if you subsequently drag that element

What's new ?

This library tackles all the issues mentioned above and provides more options and properties to the LeaderLine instance :

New Options	Description
parent	where to insert the line element, default to document.body in <1.2.0 and to the line's end element parentNode in >=1.2.0
minGridLength	The minimun line length (default to 40). Only applied to grid-pathed lines [>=1.6.0]

New Properties	Type	Description
element	SVG Element	The line svg element
removed	boolean	Indicates whether the line was removed (line.remove was called) or not [>=1.5.0]
standalone	boolean	Indicates whether the line is directly instantiated or not (ex: belongs to a LinkerLineChain instance) [>=1.5.0]

Changes :

1. pointAnchor, areaAnchor, mouseHoverAnchor are renamed to PointAnchor, AreaAnchor, MouseHoverAnchor.
2. CaptionLabel and PathLabel are merged into Label. The Label has an option named "on" that takes as a value either "path" or "element".
3. animation object "timing" property is renamed to "easing".
4. dash "len" property is renamed to "length".

Illustration

Check source code.

How to use it ?

Just install the package using npm or any package manager of your choice :

npm install --save linkerline

And then use it in your code as follows :

import LinkerLine from "linkerline";

const line=new LinkerLine({
    //...OriginalClassProps,
    parent:HTMLElement,// this is the new parent option
    start:HTMLElement,
    end:HTMLElement,
});
//line.element => returns the line svg element

Version 1.5.0 add-ons

Static Method Name	Return Value	Description
removeAll()	void	removes all standalone lines at once
getLineChain(line:LinkerLine)	LinkerLineChain | null	returns the LinkerLineChain instance the line belongs to if any

LinkerLine Chain [1.3.0]

new LinKerLine.Chain(nodes,options):LinkerLineChain;

Param Name	Type	Description
nodes	HTMLElement[]	The chain nodes
options	object	The chain options

Chain Options :

Option Name	Type	Description
linkingDuration	number	The line draw animation duration, default to 500
linked	boolean	specifies if the chain is initially linked or not, default to false
lineOptions	LinkerLineOptions	The line options
onLinkChange	(context : object) : void	Called on each node-to-node connection change

onLinkChange Context :

Property Name	Type	Description
line	LinkerLine	The connection line
startNode	HTMLElement	Same as line.start
endNode	HTMLElement	Same as line.end
nodesLinked	boolean	Indicates whether the nodes are linked or unlinked
hopIndex	number	The hop index [>=1.4.0]

LinkerLineChain:

Name	Type	Description
nodes	HTMLElement[]	gets the chain target nodes
lines	LinkerLine[]	gets the chain lines
linked	boolean	true if all nodes are fully linked, false otherwise
partiallyLinked	boolean	true if at least one line is visible, false otherwise
link	() : void	links the chain nodes
unlink	() : void	unlinks the chain nodes
pushNode	(node:HTMLElement) : void	appends a new node to the end of the chain
unshiftNode	(node:HTMLElement) : void	adds a new node at the start of the chain

Additional properties are added to nodes:

Property Name	Type	Description
outLine	LinkerLine | undefined	The linkerline instance exiting the node
inLine	LinkerLine | undefined	The linkerline instance entering the node

Illustration code :

const chain=new LinkerLine.Chain(nodes,{
    onLinkChange:({line,startNode,endNode,nodesLinked})=>{
        const color=nodesLinked?line.color:null;
        startNode.style.backgroundColor=color;
        endNode.style.backgroundColor=color;
    },
});
linkbtn.onclick=()=>{
    chain.link();
};
unlinkbtn.onclick=()=>{
    chain.unlink();
}

positionAll [1.2.0]

A new static method LinkerLine.positionAll() : void that updates all the lines'positions at once.

Custom Plugs [1.1.0]

It allows defining custom plugs via the static method LinkerLine.definePlug( options : object ).

Option Name	Type	Description
name	string (required)	plug name
shape	enum "rect","ellipse"	defines a plug via a shape
svg	string | (color:string,weight:string)=>string	defines a plug via an svg string
src	string	defines a plug via an url or base64 string
width	number	sets the plug base width
height	number	sets the plug base height
margin	number	margin between the plug and the start/end element
rotatable	boolean	indicates whether the plug should have a fixed orientation or rotate accordingly

LinkerLine.definePlug({
    name:"star",
    svg:(color,weight)=>`
        <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="${color}" stroke-width="${weight}" stroke-linecap="round" stroke-linejoin="round">
            <path d="M8.243 7.34l-6.38 .925l-.113 .023a1 1 0 0 0 -.44 1.684l4.622 4.499l-1.09 6.355l-.013 .11a1 1 0 0 0 1.464 .944l5.706 -3l5.693 3l.1 .046a1 1 0 0 0 1.352 -1.1l-1.091 -6.355l4.624 -4.5l.078 -.085a1 1 0 0 0 -.633 -1.62l-6.38 -.926l-2.852 -5.78a1 1 0 0 0 -1.794 0l-2.853 5.78z"/>
        </svg>
    `,
    width:20,
    height:20,
    rotatable:false,
});

const line=new LinkerLine({
    parent:linkerlineview,
    color:"#73f5fa",
    size:3,
    startPlug:"star",
    endPlug:"star",
});

For svgs, when a function is specified, the color and the weight params will respectively make sure that the plug will match the line color (or start/endPlugColor if specified) and thickness.