javascript - How to represent range in mongoose schema? -

background

lets doing schema fruits can buy. in schema, fruit has price range:

let fruit = {     name: "banana",     price: {         currency: "eur",         range: [2, 10]     } }; 

to achieve saving above object, trying use following schema:

let fruitschema = {     name: {type: string, required: true},     price: {         currency: {type: string, required: true},         range: [{             type: number,             min: 0         }],         validate: [arraysize]     } };  const arraysize = function arraylimit(val) {   return val.length === 2; }; 

problem:

my solution range part feels clunky, on complicated , doesn't check if max range value bigger min range value, i.e., doesn't check if 10 > 2.

question:

• how implement price range in schema in mongoose ?

my solution

i decided have both values in schema separately, in example bellow:

income: {     currency: { type: string },     range: {         min: { type: number, min: 0 },         max: { type: number, min: 0 }     } } 

problem

however, left problem. how check max >= min @ times, , min <= max ??

given nor min nor max mandatory, 1 can have object upper range, or lower one.

enter custom validators

to fix validation issue, used custom validator functions. validators missing piece in puzzle, , allowed me enforce max , min restrictions:

validate object min:

validate: {     validator: function(val){         const currmax = this.target.income.range.max;         return (currmax !== undefined ? val <= currmax : true);     },     message: "the min range value {value} must <= max range!" } 

validate object max:

validate: {     validator: function(val) {         const currmin = this.target.income.range.min;         return (currmin !== undefined ? val >= currmin : true);     },     message: "the max range value {value} must >= min range!" } 

final result

thus, final result follows:

income: {     currency: { type: string },     range: {         min: {              type: number, min: 0,             validate: {                 validator: function(val){                     const currmax = this.target.income.range.max;                     return (currmax !== undefined ? val <= currmax : true);                 },                 message: "the min range value {value} must <= max range!"             }         },         max: {              type: number, min: 0,             validate: {                 validator: function(val) {                     const currmin = this.target.income.range.min;                     return (currmin !== undefined ? val >= currmin : true);                 },                 message: "the max range value {value} must >= min range!"             }         }     } } 

going further

this solution nice, shows advanced knowledge , requirements. in try insert object min > max, have nice error message value being inserted.

however, have following questions / suggestions improvement, didn't add because don't yet know how do:

1. the validator keep inconsistent objects being inserted. however, when not prevent bad updates, i.e., following example work on object min = 10:

   objmodel.update( { _id: "58dd26b5476664e33eec4b93" }, { $set: {"income.range.max": 1}} );

to updates on objects using validators, must use save method, , follow convention described @ end of mongoose docs.

model.findone({ name: 'borne' }, function (err, doc){   doc.name = 'jason borne';   doc.visits.$inc();   doc.save(); }); 

which trigger validator expected.

2. in functions check min , max, can print value being evaluated using {value}. however, can use other values of object? when comparing min , max, useful print value being evaluated values being compared to.

hope helps, , inspires!