Node.js for Rails developers, Part 6b (MongoDB Datastore)

// app/models/robot.js

var mongoose = require( 'mongoose' );
var Schema = mongoose.Schema;

var RobotSchema = new Schema(
  {
    name : {
      type: String,
      required: true
    },
    description : {
      type: String,
      required: true
    }
  },
  {
    timestamps: { // include timestamp attributes in the schema and automatically assign values on create and update, respectively
      createdAt: 'created_at', // rename from createdAt
      updatedAt: 'updated_at' // rename from updatedAt
    }
  }
);

module.exports = mongoose.model('Robot', RobotSchema);

// db.js

var mongoose = require( 'mongoose' );
var mongoConnectionString = process.env.MONGODB_URI || 'mongodb://localhost/robots_dev';
mongoose.connect(mongoConnectionString); // establishes a database connection which may in some cases need to be manually closed ... use db.disconnect();

module.exports = mongoose;

// app.js

// ...
var db = require("./db") // MONGO ADDITION! starts a new mongoose connection
// ...

// db/seed.js

var db = require("../db"); // starts a mongoose connection
var Robot = require("../app/models/robot");

var robots = [
    {name:"c3po", description:"specializes in language translation"},
    {name:"r2d2", description:"holds a secret message"},
    {name:"bb8",  description:"rolls around"}
];

Robot.find(function (err, bots) {
    if (err) return console.error(err);
    console.log("FOUND", bots.length, "ROBOTS TO BE DELETED")

    Robot.remove(bots, function (err) {
        if (err) return console.error(err);
        console.log("DELETED")

        Robot.create(robots, function (err, new_bots) {
            console.log(new_bots)
            db.disconnect(); // close the connection, else it will keep running, which is appropriate for when the web server runs, but not for a script like this.
        });
    });
});

// app/controllers/robots_controller.js

var express = require('express');
var router = express.Router();

var Robot = require("../models/robot");
var mongooseError = require("../helpers/mongoose_error")

var create_robot_path = '/robots/';

function updateRobotPath(robot_id){
    return '/robots/'+robot_id+'/update';
};

/* INDEX */

router.get('/robots', function(req, res, next) {
    Robot.find( function (err, bots) {
      console.log("LIST", bots.length, "ROBOTS:", bots);
      res.render('robots/index', {
          page_title: 'Robots',
          robots: bots.reverse()
      });
    });
});

/* CREATE */

router.post('/robots', function(req, res, next) {
    console.log("CAPTURE FORM DATA:", req.body)
    var robot_name = req.body.robotName;
    var robot_description = req.body.robotDescription;
    var bot = new Robot({name: robot_name, description: robot_description});
    bot.save(function(saveErr, bot_id) {
        if (saveErr){
            console.log(saveErr);
            var error_messages = mongooseError.toMessages(saveErr);
            req.flash('danger', error_messages);
            res.render('robots/new', {
                page_title: 'Add a new Robot',
                form_action: create_robot_path,
                robot: {name: robot_name, description: robot_description} // pass-back attempted values to the form in case one was not blank
            });
        } else {
            console.log("CREATE ROBOT", bot)
            req.flash('success', 'Created a New Robot named '+robot_name );
            res.redirect('/robots')
        };
    });
});

/* NEW */
// this must come above the SHOW action else express will think the word 'new' is the :id

router.get('/robots/new', function(req, res, next) {
    console.log("NEW ROBOT")
    res.render('robots/new', {
        page_title: 'Add a new Robot',
        form_action: create_robot_path
    });
});

/* SHOW */

router.get('/robots/:id', function(req, res, next) {
    var robot_id = req.params.id;
    Robot.findById(robot_id, function(err, bot) {
        if (err){
            console.log("COULDN'T SHOW ROBOT #"+robot_id);
            console.log(err);
            var error_messages = mongooseError.toMessages(err);
            req.flash('danger', error_messages);
            res.redirect('/robots');
        } else {
            console.log("SHOW ROBOT:", bot);
            res.render('robots/show', {
                page_title: 'Robot #'+bot.id,
                robot: bot
            });
        };
    });
});

/* EDIT */

router.get('/robots/:id/edit', function(req, res, next) {
    var robot_id = req.params.id;
    Robot.findById(robot_id, function(err, bot) {
        console.log("EDIT ROBOT", bot);
        res.render('robots/edit', {
            page_title: 'Edit Robot #'+bot.id,
            robot: bot,
            form_action: updateRobotPath(bot.id)
        });
    });
});

/* UPDATE */

router.post('/robots/:id/update', function(req, res, next) {
    console.log("CATURED FORM DATA", req.body)
    var robot_id = req.params.id;
    var robot_name = req.body.robotName;
    var robot_description = req.body.robotDescription;
    Robot.findById(robot_id, function(err, bot) {
        bot.name = req.body.robotName
        bot.description = req.body.robotDescription
        bot.save(function(saveErr, new_bot) {
            if (saveErr){
                console.log(saveErr)
                var error_messages = mongooseError.toMessages(saveErr)
                req.flash('danger', error_messages);
                res.render('robots/edit', {
                    page_title: 'Edit Robot #'+robot_id,
                    form_action: updateRobotPath(robot_id),
                    robot: {name: robot_name, description: robot_description} // pass-back attempted values to the form in case one was not blank
                });
            } else {
                console.log("UPDATED ROBOT", new_bot)
                req.flash('success', 'Updated Robot #'+new_bot._id );
                res.redirect('/robots')
            };
        });
      });
});

/* DESTROY */

router.post('/robots/:id/destroy', function(req, res, next) {
    var robot_id = req.params.id;
    Robot.findById(robot_id, function(err, bot) {
        bot.remove( function(rmErr, removed_bot) {
            if (rmErr) {
                console.log("COULDN'T DELETE ROBOT #", bot_id);
                req.flash('danger', "Couldn't delete Robot #"+bot_id );
                var error_messages = mongooseError.toMessages(rmErr);
                req.flash("danger", error_messages)
            } else {
                console.log("DELETED ROBOT", removed_bot);
                req.flash('success', 'Deleted Robot #'+removed_bot._id );
            }
            res.redirect('/robots');
        });
    });
});

module.exports = router;

// app/helpers/mongoose_error.js

var exports = module.exports = {};

// Transform mongoose error object into error message(s).
//
// @param [ValidationError] err A mongoose error like...
//
//  {
//    message: 'Note validation failed',
//    name: 'ValidationError',
//    errors:{
//      description:{
//        message: 'Path `description` is required.',
//        name: 'ValidatorError',
//        properties: [Object],
//        kind: 'required',
//        path: 'description',
//        value: ''
//      },
//      title:{
//        message: 'Path `name` is required.',
//        name: 'ValidatorError',
//        properties: [Object],
//        kind: 'required',
//        path: 'title',
//        value: ''
//      }
//    }
//  }
//
// ... or like ...
//
//  {
//    message: 'Cast to ObjectId failed for value "abc" at path "_id"',
//    name: 'CastError',
//    kind: 'ObjectId',
//    value: 'abc',
//    path: '_id',
//    reason: undefined
//  }
//
// @return [Array] error_messages
exports.toMessages = function(err){
    if (err.name == "ValidationError") {
      var errors = err.errors
      var error_messages = Object.keys(errors).map(function(k) {
          var error = errors[k]
          return error.name+': '+error.path+' is '+error.kind //> ValidatorError: description is required
      });
    } else if (err.name == "CastError") {
        var error_messages = ["Sorry, couldn't find a robot with that identifier..."]
    } else {
        var error_messages = ["Oops, something unexpected has happened..."]
    };

    return error_messages //> ["ValidatorError: description is required", "ValidatorError: title is required"]
};