node-request-model

Mongoose-inspired Node.js / Express middleware to simplify handling requests.

Eliminates boilerplate code responsible for basic parameter validation, default value handling, and type conversion. Also, it creates an easy-to-read description of what is expected by the route.

install

npm install --save node-request-model

Usage

constmodel=require('node-request-model');// ...// Models are declared as middleware. They can be added to any route (GET, POST, etc...) and// the results will be stored in the req.model variable by default. app.post('/customer/:customer/register',model({// shorthand for {type: 'string', required: true}customer: 'string',// optional valueheight: {type: 'float',required: false},// enforce enumsfoodChoice: {type: 'string',enum: ['pizza','taco','salad']},// booleans are converted to true if the value is "true", 1, or "1", otherwise false subscribe: 'bool',// objects are always pulled from the body. This assumes json body parser was run earlierpreferences: {type: 'object'},// forces node-request-model to look first in req.body and then in req.query if no value// is found in the body. It will not look in req.params image: {type: 'string',sources: ['body','query']},// looks for "my_field" in the request and stores the result in req.model.myFieldmyField: {type: 'string',name: 'my_field'}}),(req,res)=>{// If any validation checks have failed, a 400 response is returned to the caller// Otherwise, req.model has the values (already cast to their correct types)// By default, values are pulled from req.params, req.query, and req.body (in that order)console.log('Model',req.model);res.json(req.model);})// Models are declared as middleware. They can be added to any route (GET, POST, etc...) and// the results will be stored in the req.model variable by default. app.get('/customer/:customer',model({customer: 'string'},'somethingElse'),(req,res)=>{// The optional second parameter can be used to override which property will hold the // the model outputconsole.log('Model',req.somethingElse)res.json(req.somethingElse);})

Re-using models

person.js

module.exports={firstName: "string",lastName: "string"}

address.js

module.exports={street1: 'string',street2: {type: 'string',default: ''},city: 'string',state: {type: 'string',validation: (s)=>s.length===2},// example regex test. More complex logic (e.g. country dependent)// doesn't belong in request validation logic. postalCode: {type: 'string',validation: (s)=>/^[0-9]{5}(?:-[0-9]{4})?$/.test(s)}}

In the route, models definitions can be combined using the spread operator. Nested models are not supported.

app.post('/customer',model({
...require('./person.js'),
...require('./address.js')}),(req,res)=>{// The optional second parameter can be used to override which property will hold the // the model outputconsole.log('Model',req.model)res.json(req.model);})

Functional defaults

Functions can be used to specify default values. The function will be evaluated for each request.

app.post('/customer',model({firstName: 'string',lastName: 'string',// A function can be passed as a default. // The function will be evaluated for each request.registeredAt: {type: 'int',default: Date.now}}),(req,res)=>{// req.model.registeredAt will be the current time, unless a value was explicitly// passed by the client.console.log('Model',req.model)})