select two markers & draw line between them in leaflet - leaflet

Question

I am very much new to leaflet.
I have multiple markers/circle Markers plotted on my map in leaflet.
now I have to draw line between two markers//circle Markers when I select them.
Can any one help in doing this.
var map = L.map('map').setView([51.49521, -0.10062], 13);
L.tileLayer('http://{s}.tile.cloudmade.com/BC9A493B41014CAABB98F0471D759707/997/256/{z}/{x}/{y}.png', {
maxZoom: 18,
attribution: 'Map data © OpenStreetMap contributors, CC-BY-SA, Imagery © CloudMade'
}).addTo(map);
// get all 6 points
var points = new Array(
[51.49346, -0.11518],
[51.49827, -0.06763],
[51.48331, -0.08154],
[51.52284, -0.09974],
[51.51932, -0.06695],
[51.50949, -0.1363]
);
// centerpoint
var centerPoint = new L.LatLng(51.49521, -0.10062);
var marker1 = L.marker([51.49521, -0.10062]).addTo(map);
// adding allo points to map
for (var i =0 ; i < points.length; i++)
{
// here I can use marker also(if solution is possible with markers)
L.circleMarker([points[i][0],points[i][1]]).addTo(map);
var point = new L.LatLng(points[i][0],points[i][1]);
var pointList = [point, centerPoint];
var firstpolyline = new L.Polyline(pointList, {
color: 'red',
weight: 5,
smoothFactor: 1
}).addTo(map);
}

Answer 1

You must store selection (however it can be polyline points or flag in your markers). When you select two or more markers you must add points to you polyline - it draws line on map, otherwise you must remove point from polyline. See details about polyline: http://leafletjs.com/reference.html#polyline.
See next code for example:
// Init map
var map = L.map('map').setView([53.902257, 27.561640], 13);
L.tileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png').addTo(map);
// Init selection and lines logic
var selection = [];
var polyline = L.polyline([], {color: 'red'}).addTo(map);
var onClick = function () {
var index = selection.indexOf(this);
if (index !== -1) {
this.setRadius(10);
selection.splice(index, 1);
polyline.spliceLatLngs(index, 1);
} else {
this.setRadius(25);
selection.push(this);
polyline.addLatLng(this.getLatLng())
}
};
// Init circle markers
L.circleMarker([53.90, 27.56]).on('click', onClick).addTo(map);
L.circleMarker([53.92, 27.60]).on('click', onClick).addTo(map);
L.circleMarker([53.88, 27.60]).on('click', onClick).addTo(map);
// Init selection droping on ESC pressed
L.DomEvent.on(document, 'keydown', function (e) {
if (e.keyCode === 27) {
var oldSelection = selection.slice(0);
for (var i = 0, l = oldSelection.length; i < l; i++) {
oldSelection[i].fire('click');
}
}
});
UPD:
It's analogically, see updated code:
var map = L.map('map').setView([51.49521, -0.10062], 13);
L.tileLayer('http://{s}.tile.cloudmade.com/BC9A493B41014CAABB98F0471D759707/997/256/{z}/{x}/{y}.png', {
maxZoom: 18,
attribution: 'Map data © OpenStreetMap contributors, CC-BY-SA, Imagery © CloudMade'
}).addTo(map);
// get all 6 points
var points = [
[51.49346, -0.11518],
[51.49827, -0.06763],
[51.48331, -0.08154],
[51.52284, -0.09974],
[51.51932, -0.06695],
[51.50949, -0.1363]
];
// polyline
var selection = [];
var polyline = new L.Polyline([], {
color: 'red',
weight: 5,
smoothFactor: 1
}).addTo(map);
var changeMarkerState = function (marker, select) {
if (marker instanceof L.CircleMarker) {
if (select) {
marker.setRadius(25);
} else {
marker.setRadius(10);
}
}
if (marker instanceof L.Marker) {
if (select) {
marker.options.title = 'selected';
} else {
marker.options.title = 'unselected';
}
marker.setIcon(new L.Icon.Default());
}
};
var onClick = function () {
var index = selection.indexOf(this);
if (index !== -1) {
changeMarkerState(this, false);
selection.splice(index, 1);
polyline.spliceLatLngs(index, 1);
} else {
changeMarkerState(this, true);
selection.push(this);
polyline.addLatLng(this.getLatLng())
}
};
// centerpoint
var centerPoint = new L.LatLng(51.49521, -0.10062);
var marker1 = L.marker([51.49521, -0.10062],
{title: 'unselected'}).on('click', onClick).addTo(map);
// adding allo points to map
for (var i = 0, l = points.length; i < l; i++)
{
// here I can use marker also(if solution is possible with markers)
L.circleMarker(points[i]).on('click', onClick).addTo(map);
}