javascript - Leaflet.contextmenu callbacks -

i'm struggling problem in leaflet.contextmenu library.

i got number of different maps, saved in global array. i'm using contextmenu options have contextmenu in maps. when want define callback functions, can't access arrmap[id], because function doesn't know id i'm using.

my question here is: how can give object (the id, example) callback function of leaflet.contextmenu library?

function x(){     arrmap[id] = new l.map('map'+id,{         contextmenu: true,         contextmenuwidth: 140,         contextmenuitems: [{             text: 'messung dieser position einfügen',             callback: newmeasurement         }, {             text: 'zeige koordinaten',             callback: showcoordinates         }, {             text: 'karte hier zentrieren',             callback: centermap         }]     }); }  function newmeasurement(e){ //do e , id } 

i thought like:

//function x(){... callback: newmeasurement(e,id) //...}  function newmeasurement(e,id){   console.log(id); } 

...but that's not working :(

thanks help!

you need create closure on value want.

first, read «how js closures work?» question.

then, read mdn reference closures. , then, this question how create different leaflet event handlers passing different value each handler function

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read first. try understand concept. mean it. if blindly copy-paste code, gods of stackoverflow kill kitten.

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now, want have event handler function, receive 1 parameter, like

function newmeasurement(ev){     // 'ev' , 'id' } 

that function needs receive 1 parameter, , needs have id variable somewhere. ok then, let's create function returns function:

function getmeasurementhandler(id) {     return function(ev) {         dosomething(ev, id);     } } 

that way, if run e.g.:

var handlerforid1234 = getmeasurementhandler(1234); 

that more-or-less equivalent to

var handlerforid1234 = function(ev) { dosomething(ev, 1234); } 

let's put together:

for (var id=0; id<4; id++) {     arrmap[id] = new l.map('map'+id, {         contextmenuitems: [{             text: 'somethingsomething',             callback: geteventhandlerforid(id)         }]     }); }  getcallbackfuncforid(id) {     return function(ev) {         console.log('event ', ev, ' in id ', id);     } }