MMHF: Mongoose Middleware Handlers Factory Is a package of Express middlewares to quickly perform the daily CRUD operations, catching the errors internally and sending unified formats of responses to the clients.

Examples:

Example of using factory.getMany():

const express = require('express')
const UsersModel = require('./modles/UsersModel.js')
const factory = require('mmhf') // require mmhf

const app = express()
app.get('/api/users', factory.getMany(UsersModel))

app.listen(3000, () => console.log('listening on port 3000...'))

When a client requests the endpoint /api/users the response would be:

/*
    { # 200
        status: 'success',
        results: 3
        data: [
            { 
                id: 1,
                name: 'Murat'
                age: 9
            },
            { 
                id: 2,
                name: 'Yaser'
                age: 10
            },
            { 
                id: 3,
                name: 'Omer'
                age: 10
            },
        ]
    }
*/

---

Example of using factory.getOne():

const express = require('express')
const UsersModel = require('./modles/UsersModel.js')
const factory = require('mmhf') // require mmhf

const app = express()
app.get(
  '/api/users/:id',
  factory.getOneById(UsersModel, (req) => req.params.id)
)

app.listen(3000, () => console.log('listening on port 3000...'))

When a client requests the endpoint /api/users/2 the response would be:

/*
    { # 200
        status: 'success',
        data: { 
                id: 2,
                name: 'Yaser'
                age: 10
              }
    }
*/

---

Example of using factory.createOne():

const express = require('express')
const UsersModel = require('./modles/UsersModel.js')
const factory = require('mmhf') // require mmhf

const app = express()
app.post(
  '/api/users',
  factory.createOne(UsersModel, (req) => req.body)
)

app.listen(3000, () => console.log('listening on port 3000...'))

When a client sends a POST request the endpoint /api/users with the following data, the response would be:

// REQUEST to [POST /api/users ]
{
    name: 'Saleem',
    age: 11
}
/*  RESPONSE:
    { # 201
        status: 'success',
        data: {
                id: 4,
                name: 'Saleem'
                age: 11
              }
    }
*/

API

Quick overview:

// the following are all the available methods: ---------------
// [C] Create ----
factory.createOne(Model, dataObj, options)
// [R] Read ----
factory.getMany(Model, (filterObj = {}), options)
factory.getOne(Model, filterObj, options)
factory.getOneById(Model, id, options)
// [U] Update ----
factory.updateOne(Model, filterObj, updateObj, options)
factory.updateOneById(Model, id, updateObj, options)
factory.updateOneWithSave(Model, filterObj, updateObj, options)
factory.updateOneByIdWithSave(Model, id, updateObj, options)
// [D] Delete ----
factory.deleteOne(Model, filterObj, options)
factory.deleteOneById(Model, id, options)
factory.archiveOne(Model, filterObj, options)
factory.archiveOneById(Model, id, options)

The API is pretty straightforward, there are 4 types of middlewares: CRUD [Creating middlewares, Reading middlewares, Updating middlewares, Deleting middlewares].

Creating Middlewares:

createOne(Model: MongooseModel | function, dataObj: object | function, options: object | function)

Create one document using the dataObj argument, and send the response.

• Internally uses the Mongoose method Model.create().
• operation success status code: 201.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• dataObj: object | function, The data you want to write.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• see the options available in the available options section.

---

Reading Middlewares:

getMany(Model: MongooseModel | function, filterObj: object | function, options: object | function)

Get multiple documents, search for them using the filterObj argument, and send them with a results property.

• results is the count of the documents returned from the database.
• internally uses the Mongoose method Model.find().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• filterObj: object | function, The search filter you use to find the documents.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• projection:: (defaults to null) the mongoose findOne method arguemnt, optional fields to return, read more here.
• for other options, read the options available in the available options section.

getOne(Model: MongooseModel | function, filterObj: object | function, options: object | function)

Get one document, search for it using the filterObj argument, and send the response.

• internally uses the Mongoose method Model.findOne().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• filterObj: object | function, The search filter you use to find the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• projection: (defaults to null) the mongoose findOne method arguemnt, optional fields to return, read more here.
• for other options, read the options available in the available options section.

getOneById(Model: MongooseModel | function, id: ObjectId | string | function, options: object | function)

Get one document, search for it by its ID, and send the response.

• internally uses the Mongoose method Model.findById().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• id: ObjectId | string | function, The ID of the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• projection:: (defaults to null) the mongoose findOne method arguemnt, optional fields to return, read more here.
• for other options, read the options available in the available options section.

---

Updating Middlewares:

updateOne(Model: MongooseModel | function, filterObj: object | function, updateObj: object | function, options: object | function)

Update one document, search for it using the filterObj argument, update the specified fields specified in the updateObj argument, and send the response.

• Internally uses the Mongoose method Model.findOneAndUpdate().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• filterObj: object | function, The search filter you use to find the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• updateObj: object | function, the data you want to write on the document if found.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• queryOptions: uses { new: true, runValidators: true } internally by default.
• for other options, read the options available in the available options section.

updateOneById(Model: MongooseModel | function, id: ObjectId | string | function, updateObj: object | function, options: object | function)

Update one document, search for it using the by its ID, update the specified fields specified in the updateObj argument, and send the response.

• Internally uses the Mongoose method Model.findByIdAndUpdate().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• id: ObjectId | string | function, The ID of the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• updateObj: object | function, the data you want to write on the document if found.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• queryOptions: uses { new: true, runValidators: true } internally by default.
• for other options, read the options available in the available options section.

updateOneWithSave(Model: MongooseModel | function, filterObj: object | function, updateObj: object | function, options: object | function)

Update one document, search for it using the filterObj argument, update the specified fields specified in the updateObj argument, and send the response. This method has the benefit of running the Mongoose 'save' hooks/middlewares, it also fires the Mongoose findOne middleware because it first searches for the specified document, and then merges the updates specified in the updateObj argument with the original data in the document.

• Internally uses the Mongoose method Model.findOne() and Document.save().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• filterObj: object | function, The search filter you use to find the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• updateObj: object | function, the data you want to write on the document if found.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• saveQueryOptions: options you want to pass to the Mongoose Document.save() method, see the official Mongoose .save() method docs for these options.
• for other options, read the options available in the available options section.

updateOneByIdWithSave(Model: MongooseModel | function, id: ObjectId | string | function, updateObj: object | function, options: object | function)

Update one document, search for it using the filterObj argument, update the specified fields specified in the updateObj argument, and send the response. This method has the benefit of running the Mongoose 'save' hooks/middlewares, it also fires the Mongoose findOne middleware because it first searches for the specified document, and then merges the updates specified in the updateObj argument with the original data in the document.

• Internally uses the Mongoose method Model.findOne() and Document.save().
• operation success status code: 200.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• id: ObjectId | string | function, The ID of the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• updateObj: object | function, the data you want to write on the document if found.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• saveQueryOptions: options you want to pass to the Mongoose Document.save() method, see the official Mongoose .save() method docs for these options.
• for other options, read the options available in the available options section.

---

Deleting Middlewares:

deleteOne(Model: MongooseModel | function, filterObj: object | function, options: object | function)

Delete one document, search for it using the filterObj argument, and send the response.

• Internally uses the Mongoose method Model.findOneAndDelete().
• operation success status code: 204.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• filterObj: object | function, The search filter you use to find the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• sendDeletedDoc: boolean, (default false) send the document which got deleted with the response.
  • Note: since the default status code is 204, you're most likely not going to see the body of the response on the client-side, (for example when you're using PostMan).
• for other options, read the options available in the available options section.

deleteOneById(Model: MongooseModel | function, id: ObjectId | string | function, options: object | function)

Delete one document, search for it by its ID, and send the response.

• Internally uses the Mongoose method Model.findByIdAndDelete().
• operation success status code: 204.

parameters:

• Model: function | Mongoose model.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return a Mongoose Model.
• id: ObjectId | string | function, The ID of the document.
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.
• options: object | function
  • When a function is provided, it will be called with the express req object as the first parameter.
  • If a function is provided, it must return an object.

Available options:

• sendDeletedDoc: boolean, (default false) send the document which got deleted with the response.
  • Note: since the default status code is 204, you're most likely not going to see the body of the response on the client-side, (for example when you're using PostMan).
• for other options, read the options available in the available options section.

archiveOne(Model: MongooseModel | function, filterObj: object | function, options: object | function)

• 🧪 This middleware is here for experimental purposes only, and it might get removed at any time.
• ⚠️ Don't use this middleware, as it's not guaranteed, you've been warned.

Soft delete a document by setting a _archived property on the document with the current timestamp indicating the time of archiving, when this property is set, you should filter any find query using mongoose to search only for the documents that don't have the _archive property.

• Internally uses the Mongoose methods Model.findOne() and Model.findOneAndUpdate().
• operation success status code: 204.

archiveOneById(Model: MongooseModel | function, id: ObjectId | string | function, options: object | function)

• 🧪 This middleware is here for experimental purposes only, and it might get removed at any time.
• ⚠️ Don't use this middleware, as it's not guaranteed, you've been warned.

Soft delete a document by setting a _archived property on the document with the current timestamp indicating the time of archiving, when this property is set, you should filter any find query using mongoose to search only for the documents that don't have the _archive property.

• Internally uses the Mongoose methods Model.findOne() and Model.findOneAndUpdate().
• operation success status code: 204.

Available Options

All the middlewares share the following options:

sendRes: {}, // default value
queryOptions: {}, // default value
callNext: false, // default value
statusCode,
resBody, // if array { $$data: doc } else { data: doc }

• sendRes: object, the options you want to pass to the sendRes module, mmhf defaults to the default configurations of sendRes, if you want to configure how your response styles, use this property. see the available options for this property object on the official docs of sendRes.
• queryOptions: object, the options you want to pass down to the query method, these are passed directly down to the mongoose query method which is in use, for instnce, if you're using factory.getOneById(Model, (req)=> req.params.id, { queryOptions: { strictQuery: false } }), the strictQuery: false you wrote is going to be passed to the inner Model.findOneById mongoose method. If you want to see the available options for each query, refer to the official Mongoose documentation for this purpose.
• callNext: boolean, If you have an express middleware that you want to execute after running one of the middlewares, use this option to make the middleware you're using call the express next() function internally.
  • Note: even if this option was set to true, the response will be sent, either way, and you can't send a response twice.
• statusCode: number, the success status code, refer to the API section to know the default success status code for each middleware.
• resBody: the response body, what you pass here goes directly to the sendRes package.

all the middlewares except [createOne(), getMany()] uses the following options:

notFoundErr: true,
notFoundMsg: 'No record found with that ID',
notFoundStatusCode: 404,
handleNotFoundErr: true

• notFoundErr: call next with an error if the requested document was not found (default to true).
• notFoundMsg: the message property will be in the response if a document was not found.
  • of course, this option will only have an effect if the notFoundErr option was true.
• notFoundStatusCode: the status code to include in the error (default 404).
• handleNotFoundErr: send the response automatically (default: true), if you disable that, you must handle the not found errors in an express error handling middleware, the error name is always: 'factoryNotFoundError'.

all the middlewares except createOne() uses the following options:

chain: (query) => query

• chain: gets called with the mongoose query as the first argument, here you can hang mongoose methods like .sort(), .select(), .transform(), .pre() ...etc.

For more options, refer to each middleware in the API above to see if any other options are available per each middleware.

Error handling

MMHF depends on express-async-handler, it performs the asynchronous tasks normally, and when it catches an error, it internally calls next() with the error, you can then use that error to handle it the way you want in your express error handling middleware.

The errors can be one of two types:

1. a mongoose error, such as validation errors, casting errors, or duplicate fields errors, for this you need to read the official docs of Mongoose, and you need to handle these errors in an express error handling middleware.
2. an mmhf error and the only error that mmhf have is the not found error, when it tries to search for a document, then it can't find that document, for this, mmhf throws a 'factoryNotFoundError', if the mmhf middleware you're using has the option handleNotFoundErr: true, then the error will not be called by next(), otherwise, mmhf calls next() with the error which you should by then handle within your express error handling middleware.

---

Originally Created at: 05 - July - 2022