mongoof

Mongoof

A less-error-prone alternative syntax for Mongoose.

Introduction

If you're like me, won't go through Mongoose without making those damn casting errors then this library is for you.

The syntax has been designed to get the most out of Mongoose with simple and elegant syntactic sugar. The API is a small and intuitive one compared to Mongoose. For me, it made me way more productive and feel confident about my models.

Install

Install with npm

$ npm install --save mongoof

Guide

There should be a model for each collection in your database, this model will be used to validate data and to communicate with the database system for CRUD operations.

Your models will have three objects:

const Model = require("mongoof").model;

// collection name
new Model("users")
.schema({
	// Object 1 Schema [REQUIRED]
})
.options({
	// Object 2 Options [OPTIONAL]
})
.methods({
	// Object 3 Methods [OPTIONAL]
})
.compile(); // don't forget to compile

Declaring a Schema

A schema defines your data in several ways: which data type to expect (Array, Object, String, Date ...etc), the default value, and other validation properties like the maximum or minimum values.

Typically with mongoof, you can do 4 things:

1. Declaring Data types

Data types declaration is the most basic validation, and is required for each key.

Example: A store items schema:

const Model = require("mongoof").model;
new Model("store")
.schema({
	title:{
		type:Model.String,
	},
	price:{
		type:Model.Number,
	},
	numOfOrders:{
		type:Model.Number,
	},
	htmlDescription:{
		type:Model.String
	}
});

If you're only declaring data types then you can use short hands:

const Model = require("mongoof").model;
new Model("store")
.schema({
	title: Model.String,
	price: Model.Number,
	numOfOrders: Model.Number,
	htmlDescription:Model.String
});

• Model.String
• Model.Number
• Model.Date
• Model.Buffer
• Model.Boolean
• Model.Mixed (can accept various types)
• Model.Array
• Model.ObjectId (when referencing other document's IDs)
• Model.Virtual (we'll discuss this one in a bit)

NOTE

Please note how each data type is capitalized and prefixed with Model

2. Declaring Validations

Declaring a data type can be considered as a validation, however, you can define more validation. And there are two types of validations:

Functional validations

Functional validation can be used to implement any kind of validation. When defining a schema the validate key can take either an object (single functional validator) or array (a set of functional validators).

The model will assume that those functions are synchronous. However if a function takes two arguments then the second arguments will be considered as a callback thus the function will be treated as an asynchronous function.

{
	email:{
		type:Model.String,
		validate:{
			validator:function(email){
				if(email.indexOf("@") < 1 || email.indexOf(".") < 1) return false;
				else return true;
			},
			msg:"Sorry your email appears to be invalid"
		}
	}
}

Example 2: A set of Asynchronous/Synchronous validators

{
	email:{
		type:Model.String,
		validate:[
			// validation 1: Asynchronous
			{
				validator:function(value,callback){
					setTimout(function(){
						callback(true);
					},500)
				},
				message:"Error message"
			},
			// validation 2: Synchronous
			{
				validator:function(value){
					return true;
				},
				message:"Error message"
			}
		]
	}		
}

NOTE

If you don't want to set a custom error message then you can use the short hand, by defining a function instead of the object.

Built-in validations

For simple and common validations, there are few built-in validators that you can use:

• For all data types:
  • required
• For numbers:
  • min
  • max
• For strings:
  • enum
  • match
  • maxlength
  • minlength

{
	gmail:{
		type:String,
		required:true,
		match:[/\w+@gmail\.com/,"You should use gmail"],
		minlength:[10,"Email is not long enough"],
		maxlength:[99,"Email is too long"]
	},
	portfolio:{
		type:Model.Array,
		required:true
	},
	favoriteFootballTeam:{
		type:Model.String,
		enum:["Liverpool","Chelsea","Arsenal"]
	},
	height:{
		type:Model.Number,
		min:[50,"Your hight should be more than 50 cm to watch the game"],
		max:[280,"You'll block others from watching if we let you in :( sorry!"],
	}
}

3. Declaring Modifiers

Schematic modification is a function that transforms a specific value into another before being saved in MongoDB.

Example: This can be useful for example when saving email addresses, since it should be case-insensitive, but a user input might be uppercased, lowercased, capitalized .. etc, To make sure we have a consistent letter-casing, we would apply a modifier:

{
	email:{
		type:Model.String,
		modify:function(value){
			return value.toLowerCase();
		},
		// validators will always apply after modification
		// so this validation will always pass
		validate:{
			validator:(value) => value.toLowerCase() === value,
			msg:""
		}
	}
}

Asynchronous Example

{
	email:{
		type:Model.String,
		modify:function(value,callback){
			setTimeout(function(){
				callback(value.toLowerCase());
			},2000);
		},
	}
}

4. Declaring Virtual Getters

Virtual values are values that depends on stored values but not persisted (stored) there.

Example: if you had a key firstName and another key lastName and your API utilizes the full name (firstName + " " + lastName), you can define a virtual value that computes the full name based on the firstName and lastName, but it's not stored in your database, yet whenever you read values through this model, you get the virtual value too.

Example 1: Getting absolute path of a file:

{
	file:{
		// a relative path would be something like: /uploads/filename.png
		relativePath:Model.String,
		// absolute path is computed based on the relative path:
		absolutePath:{
			type:Model.Virtual // it will not be persisted
			getter:function(){
				// this refers to the whole document
				return path.join(process.cwd(),"public",this.file.relativePath);
			}
		}
	}
}

Example 2: Seeing whether a book is available or not based on multiple values

// a store bought a number of copies
// they rented some
// then sold some
// they found some of copies were damaged
// and then fixed some
// how would they calculate the available copies?
{
	bought:Model.Number,
	rented:Model.Number,
	sold:Model.Number,
	damaged:Model.Number,
	fixed:Model.Number
	available:{
		type:Model.Virtual,
		getter:function(){
			return this.bought - this.rented - this.sold - this.damaged + this.fixed;
		}
	}	
}

Example 3: Asynchronous currency conversion

const GBP2USD = require("gbp2usd");

//...

{
	price:Model.Number,
	usdPrice:{
		type:Model.Virtual,
		getter:function(callback){
			GBP2USD(this.price,function(priceInUSD){
				callback(priceInUSD);
			});
		}
	}	
}

Conclusion

Here's an example of an almost finished schema

const Model = require("mongoof").model;

// this model is for a book store
// we'll use this library to validate ISBN numbers
const validateISBN = require("isbn-validator");
// currency conversion library
const gbp2usd = require("gbp2usd");
// 
new Model("books")
.schema({
	title:Model.String,
	author:Model.String,
	year:{
		type:Model.Number,
		// using built-in validators
		max:2020,
		min:1500,
	},
	publisher:Model.String,
	ISBN:{
		type:Model.String,
		validate:{
			// The ISBN validator is asynchronous and promise based
			validator:function(value,callback){
				validateISBN(value)
				.then(function(valid){
					callback(valid)
				})
				.catch(function(err){
					callback(false);
					console.log(err);
				});
			},
			msg:"Invalid ISBN number"
		}
	},
	copies:{
		type:Model.Number,
		min:0
	},
	price:{
		type:Model.Number,
		min:0
	},
	// virtual value
	usdPrice:{
		type:Model.Virtual,
		getter:function(callback){
			GBP2USD(this.price,function(priceInUSD){
				callback(priceInUSD);
			});
		}
	}
	previewPages:[
		{
			number:{
				type:Model.Number,
				min:1
			},
			img:{
				type:Model.String,
				// this modifer will write a base64 encoded image
				// and save a string referring to the path of the image
				// instead of the base64 string
				modify:function(base64,callback){
					if(base64.length < 50) callback(base64); // it's not base64
					else {
						base64 = base64.replace(/^data:image\/\w+;base64,/, '');
						// random file name generation
						let filename = Math.random().toString(36).substr(4)+".png";
						let filePath = "uploads/previews/"+filename;
						fs.writeFile(filePath, base64, {encoding: 'base64'}, function(err){
							callback(filePath);
						});
					}
				}
			}
		}
	]
})

Declaring Methods

Methods are CRUD operations (create, read, update and delete) performed on the collection the model concerned with.

CRUD operations in mongoof are promise base.

Mongoof CRUD API is rather simple, but very expressive:

Example reading all entries from a collection

const Model = require("mongoof").model;

new Model("users")
.schema({/* .. */})
.methods({

	MethodName:function(){
		// ..
		return new Promise(function(resolve,reject){
			this.read()
			.then(function(out){
				resolve(out);
			})
			.catch(function(err){
				reject(err);
			})
			
		});
	}
})

As you can see from the above example this keyword refers to the collection and read applies an operations, and returns a promise.

This is referred to as query statement.

A query statement is composed of:

• this keyword [REQUIRED]
• Selector [optional] (example: where)
• Modifier [optional] (example: sort)
• Runner [REQUIRED] (example: read)

A query statement SHOULD begin with this and end with a runner.

Available selectors:

The only selector available is the where selector. but you can apply operators on it as you wish.

• Simple where selector:

	this.where({key1:"value1",key2:"value2"}).read()

Comparison Operators

• Operator: greater than

	this.where({age:{$gt:18}}).read()

• Operator: less than

	this.where({age:{$lt:18}}).read()

• Operator: greater or equal to

	this.where({age:{$gte:18}}).read()

• Operator: less or equal to

	this.where({age:{$lte:18}}).read()

• Operator: NOT equal to

	this.where({age:{$ne:18}}).read()

• Operator: Equal to one of these values

	this.where({key:{$in:[0,2,4,6,8]}}).read()

• Operator: NOT in one of these values

	this.where({key:{$nin:[1,3,5,7,9]}}).read()

Logical Operators

• Operator: or

	this.where({$or:[{quantity:{$lt:20}},{price:10}]}).read();

• Operator: and

	this.where({$and:[{quantity:{$lt:20}},{price:10}]}).read();

• Operator: not

	this.where({price:{$not:{$gt:1.99}}}).read();

• Operator: nor

	this.where({$nor:{available:false,mark:{$lt:50}}}).read();

Primary Operators

• Operator: exists

	this.where({refundedAmount:{$exists:true}}).read();

• Operator: type

	this.where({zipCode:{$type:"string"}}).read();

Evaluation Operators

• Operator: mod (reminder of division)

	this.where({copies:{$mod:[2,0]}}).read(); // even
	this.where({copies:{$mod:[2,1]}}).read(); // odd

• Operator: regular expression

	this.where({email:{$regex:/\w+@gmail\.com/}}).read();

Available Modifiers

Modifier	When?	default	possible	example
distinct	reading	false	"any key"	this.distinct("name").read()
sort	reading	NaN	-1,1	this.sort({lastName:-1,age:1}).read()
limit	reading	false	=> 0	this.limit(10).read();
skip	reading	false	=> 0	this.skip(10).read();
upsert	updating	false	true,false	this.where({a:5}).upsert(true).update({a:10})
multi	updating	false	true,false	this.where({a:5}).multi(true).update({a:10})

NOTE

Upsert means that if no document did satisfy the where selector criteria, create a new one. While update means that if multiple documents satisfied the where selector criteria, update them all.

NOTE

sort,limit and skip are usually used together for pagination. Example: this.sort({time:-1}).limit(10).skip(10).read();

Available Runners

Runners are the last methods in the query statement, they run the query, and return a promise

read

Takes no argument to read all the fields, takes an array of arguments to read specific set of fields, or takes a string to read only one field

	// all
	this.read();
	// only full name
	this.read("fullname");
	// age and last hospitalization date
	this.read(["age","lastHospitalizationDate"]);

create

Create new document, takes one argument as the document to be created:

this.create({
	firstName:"Alex",
	lastName:"Corvi",
	email:"[e-mail]",
	
})

delete

Deletes all documents that satisfies the where criteria, when no where selector is used it will empty the collection.

this.where(age:{$lt:19}).delete(); // delete all non-adult users
this.delete(); // delete all user

update

Update specific fields in a document(s) that satisfies the where criteria.

this.where({lastLoggedIn:{$lt:1384655207000}}).multi(true).update({active:false});

unset

Removes a field from the document

this.where({active:false}).unset({salary:"",anotherKey:""});
// short hand (to unset only one value):
this.where({active:false}).unset("salary");

increment

Increment a numerical value

this.where({title:"salesman"}).inc({salary:300}); // a raise for salesmen

this.where({title:"CEO"}).inc({salary:-300}); // :(

push

Pushing a value to an array

this.where({name:"Alex Corvi"}).push({projects:"mongoof"});

PushAll

Pushing multiple values to an array

this.where({name:"Alex Corvi"}).pushAll({projects:["mongoof","vunode","pul"]});

pull

Removes a value from an array

this.where({name:"Alex Corvi"}).pull({todos:"mongoof"});

pullAll

Removes a value from an array

this.where({name:"Alex Corvi"}).pullAll({todos:["mongoof","vunode"]});

addToSet

Push a value to an array only if it doesn't exists already

this.where({name:"Alex Corvi"}).addToSet({projects:"mongoof"});

addAllToSet

Push multiple values to an array if they don't exist already

this.where({name:"Alex Corvi"}).addAllToSet({projects:["mongoof","vunode","pul"]});

pop

pop an item out of an array

this.where({name:"Alex"}).pop({wishlist:-1}); // pops the last item
this.where({name:"Alex"}).pop({wishlist:1}); // pops the first item

How to call a method?

Now in our model, we defined these methods:

const Model = require("mongoof").model;

new Model("users")
.schema({/* ... */})
.methods({
   read:function(){
	   return new Promise(function(resolve,rejects){
		   this.read()
		   .then(function(out){
			   resolve(out);
		   })
	   })
   }
})
.compile(); // don't EVER, EVER, EVER forget to compile

Somewhere else (in our API maybe .. ):

const Model = require("mongoof").model;
Model("users").read(); // will call the function we defined above

Options

Last but not least, the options object, which is just wrapper around mongoose schema options

find out more

Mongoose aliases:

require("mongoof").connect === require("mongoose").connect require("mongoof").connection === require("mongoose").connection

CRUD library outside model methods

const crud = require('mongoof').crud;
new crud("collectionName").read() // returns a promise just like this.read();