customize CRUD operation in loopback js - node.js

Question

i am new to loopback js trying to create remote method Create,Read,update and delete operation.
i have created a model name class and now i want to write the crud operation in my project file
models/class.js file.
'use strict';
module.exports = function(Class) {
};
I have no idea how to do it , read docs but does not clearify things if anyone can give example to write CRUD operation would be better understanding. (Using loopback 3 for practice.)

Answer 1

To create a custom method for a model, you need to do two things:
1/ Create the method within your model like this:
module.exports = function (Mymodel) {
Mymodel.myCustomMethod = function (req, res, cb) {
// method body
}
}
2/ To declare the remote to your model, so it can be exposed
module.exports = function (Mymodel) {
/* custom methods, hooks, ... */
Mymodel.remoteMethod(
'myCustomMethod', {
http: {
path: '/myCustomMethod',
verb: 'post' // it could also be 'post', 'put', 'delete'
},
accepts: {
arg: 'data',
type: 'object', // accepting an object in the body
'http': {
source: 'body' // Reading the body of the request. It could also be 'req' to read the req url for parameters.
}
},
returns: {
type: 'object', // Returns an object to the front
root: true
}
}
)
}
This is an example for a 'post' remote method. A 'put' remote method will look exactly the same, except for the keyword 'put' instead of 'post'.
For a 'get' or 'delete' requests, only the request url will be read, so the remote method should contain:
http: { path: '/myCustomMethod/:projectId', verb: 'get' },
accepts: { arg: 'projectId', type: 'number' },
With projectId the name of a property given in the URL, and number being the type of projectId.