PROBLEM
Let’s assume we have the following JSON data:-
[
{
"date": "2015-07-30",
"calendarAppointmentPtoJsonBeans": [
{
"basicEmployeeJsonBean": {
"id": 1,
"name": "Vrabel"
}
}
]
},
{
"date": "2015-07-31",
"calendarAppointmentPtoJsonBeans": [
{
"basicEmployeeJsonBean": {
"id": 2,
"name": "Cray"
}
},
{
"basicEmployeeJsonBean": {
"id": 1,
"name": "Vrabel"
}
},
{
"basicEmployeeJsonBean": {
"id": 3,
"name": "Haeflinger"
}
}
]
}
]
What we want to do is to get all unique employees and ordered them by their names so that we get the following data:-
[
{
"id": 2,
"name": "Cray"
},
{
"id": 3,
"name": "Haeflinger"
},
{
"id": 1,
"name": "Vrabel"
}
]
SOLUTION 1: Less Elegant
Underscore.js provides various functions that allow us to pull this off.
var employees = _.sortBy( _.unique( _.pluck( _.flatten(
_.pluck( jsonData, 'calendarAppointmentPtoJsonBeans' ) ),
'basicEmployeeJsonBean' ), function ( employee ) {
return employee.id;
} ), function ( employee ) {
return employee.name;
} );
While doable, the code is virtually not readable.
If you hate your peers and life, this is what you would write.
SOLUTION 2: More Elegant
The good news is Underscore.js also provides _.chain(..) that allows us to do the same thing through method chaining:-
var employees = _.chain( jsonData )
.pluck( 'calendarAppointmentPtoJsonBeans' )
.flatten()
.pluck( 'basicEmployeeJsonBean' )
.unique( function ( employee ) {
return employee.id;
} )
.sortBy( function ( employee ) {
return employee.name;
} )
.value();
Very nice solution!