arrays - Group by on a complex object in AngularJS -

i've array contains assignments of employees on tasks, looks this:

$scope.assignments = [     {        employee: {         id:"1", firstname:"john", lastname:"rambo"       },       task: {         name:"kill everyone", project:"destruction"       },       date: {         day:"01/01", year:"1985"       }     },     {       employee: {         id:"2", firstname:"luke", lastname:"skywalker"       },       task: {         name:"find daddy", project:"star wars"       },       date: {         day:"65/45", year:"1000000"       }             },     {       employee: {         id:"1", firstname:"john", lastname:"rambo"       },       task: {         name:"save world", project:"destruction"       },       date: {         day:"02/01", year:"1985"       }     } ]; 

i group employee, having this:

$scope.assignmentsbyemployee = [     { //first item       id:"1",        firstname:"john",       lastname:"rambo",       missions: [         {           name:"kill everyone",           date:"01/01",           year:"1985"         },         {           name:"save world",           date:"02/01",           year:"1985"         }       ]     },     { //second item       id="2",       firstname:"luke",       lastname:"skywalker",       missions: [         name:"find daddy",           date:"65/45",           year:"1000000"                ]    } ]; 

is simple way ? tried double foreach, leads me nowhere.

hope i'm understandable :)

thanks !

you should able loop through assignments array , create 'keyed array' (which means using object in javascript) on employee id. fill missions array required.

something like

// initialise holding object var assignmentsbyemployee = {};  // loop through assignemnts for(var = 0; < $scope.assignments.length; i++) {     // grab current assignment     var currentassignment = $scope.assignments[i];     // grab current id     var currentid = currentassignment.employee.id;      // check if have seen employee before     if(assignmentsbyemployee[currentid] === undefined) {         // haven't, add new object array         assignmentsbyemployee[currentid] = {             id: currentid,             firstname: currentassignment.employee.firstname,             lastname: currentassignment.employee.lastname,             missions: []         };     }      // know employee exists @ point, add mission details     assignmentsbyemployee[currentid].missions.push({         name: currentassignment.task.name,         date: currentassignment.date.day,         year: currentassignment.date.year     }); } 

these leaves assignmentsbyemployee object, can foreach through , convert array if required. e.g:

$scope.assignmentsbyemployee = []; for(var employeeid in assignmentsbyemployee) {     $scope.assignmentsbyemployee.push(assignmentsbyemployee[employeeid]); }