Teaching Guide

Description

Mongoose Basics is an ORM for MongoDB.

Mongoose Slides: http://bit.ly/elf-mongoose
Prog219 Resources

NOTE: There is an Angular, React and jquery version of this assignment. Make sure you are looking at the right one. This is the jquery assignment, the others are called AngularMongooseBasics and ReactMongooseBasics.

Step One

CreateAllExpress Week10-MongooseBasics
cd Week10-MongooseBasics
npm install

Open the project in Web Storm.

Step Two

Set up bower

bower install bootstrap --save

Now might be a good time to start the project: npm start

Ignore Scientists

Add a file called nodemon.json in the root of your project. Place the following content in it:

{
  "verbose": true,
  "ignore": ["scientists.json", "**/components/**"]
}

This project is going to create a file called scientists.json each time you insert data into the database. By default, this will cause nodemon to restart the project each time we write data to scientists.json. This can cause miscellaneous errors on the on the client side, such as a false report for failure for the insertValidCollection. The fix is to ask nodemon to ignore scientists.json. We should also ask it to ignore our components folder.

For more on nodemon configuration, see here:

You should also create a .gitignore file for this project and put the single line scientists.json in it.

Step Three

Let's practice setting up the favicon. Because you used CreateAllExpress, you should already have a favicon.png file in public. But in case you have some reason to do it manually, here is how to get a default favicon on Linux (first example) or on Windows:

cp $JSOBJECTS/Data/MongoBootstrap/favicon.png public/.
copy %USERPROFILE%\Git\JsObjects\Data\MongoBootstrap\favicon.png public\.

The next step is not done for you automatically by CreateAllExpress, so do this by hand:

In an editor, open up app.js from the root of your project. (Server side)
On line 18 uncomment: app.use(favicon(__dirname + '/public/favicon.ico'));
Change favicon.ico to favicon.png.

Step Four

Set up and learn a little about Mongoose. Mongoose is by far the most popular way to access MongoDb from Node Js applications.

First install mongoose:

npm install mongoose --save

You may see messages about mongoose, C++ and bson. If you are concerned about them, see the Elvenware notes on this subject.

NOTE: On Linux, you may need to install libkrb5-dev before you can install the Mongoose NPM package. This should not be an issue on Cloud 9.

sudo apt-get install libkrb5-dev

The Mongoose Schema

Once Mongoose is installed, you should set up a schema:

Create a folder called models at the root of your project
Put this code in a file called models/presidents.js:

var mongoose = require('mongoose');

var presidentsSchema = mongoose.Schema({
    "firstName": String,
    "lastName": String,
});

module.exports = mongoose.model('presidents', presidentsSchema);

While we are at it, let's create a more complex schema which we can use once we learn the basics. Put the follow code in a file called models/scientists.js.

var mongoose = require('mongoose');

var scientistsSchema = mongoose.Schema({
    "firstName": String,
    "lastName": String,
    "subject": String,
    "subjects": [String],
    "comments": [{ commentText: String, date: Date }]
});

module.exports = mongoose.model('scientists', scientistsSchema);

In routes/index.js do these two things:

var scientists = require('../models/scientists');
var presidents = require('../models/presidents');
var mongoose = require('mongoose');

And then create methods to open your collection:

In index.js, make sure that this is the last line in the file:

module.exports = router;

Connecting

Here is a tool for connecting to the database. It belongs in its own file called routes/connect.js:

var mongoose = require('mongoose');

var connect = {

    connected: false,

    simpleConnect: function() {
        'use strict';
        var url = 'mongodb://127.0.0.1:27017/test';
        connect.connected = true;
        mongoose.connect(url);
        var db = mongoose.connection;
        db.on('error', console.error.bind(console, 'connection error:'));
        db.once('open', function(callback) {
            connect.connected = true;
            console.log('Opened connection to mongo');
        });
    },

    mlabConnect: function() {
        'use strict';
        connect.connected = true;
        var userName = 'foo';
        var password = 'foobar';
        var siteAndPort = 'ds049848.mongolab.com:49848';
        var databaseName = 'elvenlab01';
        var url = 'mongodb://' + userName + ':' + password + '@' + siteAndPort + '/' + databaseName;
        console.log(url);
        mongoose.connect(url);

        // This part is optional
        var db = mongoose.connection;
        db.on('error', console.error.bind(console, 'connection error:'));
        db.once('open', function(callback) {
            connect.connected = true;
            console.log('Opened connection to mongo');
        });
    },

    doConnection: function(useSimple) {
        'use strict';
        var connectType = useSimple || true;
        if (connectType) {
            connect.simpleConnect();
        } else {
            connect.mlabConnect();
        }
    }

};

module.exports = connect;

Step 5

Here is index.jade:

extends layout

block content
  h1= title
  p Welcome to #{title}

    button#insertValidData Insert Valid Data
    button#getAll Get All
    button#emptyCollection Empty Collection

  pre#display

and layout.jade

doctype html
html
  head
    title= title
    link(rel='stylesheet', href='/stylesheets/style.css')
    link(rel='stylesheet', href='/components/bootstrap/dist/css/bootstrap.css')
    script(src="components/jquery/dist/jquery.js")
    script(src="components/bootstrap/dist/js/bootstrap.js")
    script(src="javascripts/control.js")
  body
    block content

Step Six

Here is public/javascripts/control.js:

$(document).ready(function() { 'use strict';
    var insertUrl = '/insertValidCollection';

    function insertCollection() {
        var jqxhr = $.get(insertUrl, function(result) {
            alert( "success" );
            console.log(JSON.stringify(result, null, 4));
        })
            .done(function() {
                console.log( "second success" );
            })
            .fail(function() {
                alert( "error" );
            })
            .always(function() {
                console.log( "finished" );
            });
    }

    $('#insertValidData').click(insertCollection);

    $("#getAll").click(function() {
       $.getJSON('/all-data', function(result) {
           $('#display').html(JSON.stringify(result, null, 4));
       })
    });
});

Step Seven

In routes/index.js append all of the following before the module statement:

var express = require('express');
var router = express.Router();
var scientists = require('../models/scientists');
var allMongo = require('./all-mongo');
var connect = require('./connect');

/* GET home page. */
router.get('/', function(req, res, next) {
    'use strict';
    res.render('index', {
        title: 'Week09-MongooseBasics'
    });
});

var connected = false;

router.get('/all-data', function(request, response) {
    'use strict';
    console.log('AllData route invoked.');
    if (!connect.connected) {
        connect.doConnection();
    }

    console.log('About to find scientists.');
    scientists.find({}, function(err, allData) {
        console.log(allData.length);
        console.log(allData[0]);

        allMongo.writeData('scientists.json', allData);

        response.send({
            result: 'Success',
            allData: allData
        });
    });
});

router.get('/emptyCollection', function(request, response) {
    'use strict';
    if (!connect.connected) {
        connect.doConnection();
    }

    scientists.remove({}, function(err) {
        if (err) {
            response.send({
                result: 'err',
                err: err
            });
        } else {
            response.send({
                result: 'collection removed'
            });
        }
    });
});

router.get('/insertValidCollection', function(request, response) {
    'use strict';
    allMongo.readDataAndInsert(response);
});

router.get('/:id', function(request, response) {
    'use strict';
    response.render(request.params.id, {});
});

module.exports = router;

All Mongo

In routes/all-mongo.js:

/**
 * Created by charlie on 6/5/16.
 */

var express = require('express');
var connect = require('./connect');
var Scientists = require('../models/scientists');
var fs = require('fs');
var totalScientistsSaved = 0;

function allMongo() {
    'use strict';
}

allMongo.numberOfScientists = 0;

function insertScientist(scientist, response) {
    'use strict';
    if (!connect.connected) {
        connect.doConnection();
    }
    var newScientist = new Scientists({
        'firstName': scientist.firstName,
        'lastName': scientist.lastName,
        'subject': scientist.subject,
        'subjects': scientist.subjects,
        'comments': scientist.comments
    });

    console.log('inserting', newScientist.lastName);

    newScientist.save(function(err) {
        totalScientistsSaved++;
        console.log('saved: ', newScientist.lastName, allMongo.numberOfScientists, totalScientistsSaved);

        if (totalScientistsSaved === allMongo.numberOfScientists) {
            response.send({
                result: 'Success Saving Scientists',
                totalSaved: totalScientistsSaved
            });
        }
    });
}

allMongo.writeData = function(fileName, data) {
    'use strict';
    var dataAsString = JSON.stringify(data, null, 4);
    fs.writeFile(fileName, dataAsString, function(err, result) {
        if (err) {
            throw (err);
        }
        console.log('success writing file');
    });
};

allMongo.readDataAndInsert = function(response) {
    'use strict';
    fs.readFile('ValidScientists.json', function(err, scientistsText) {
        if (err) {
            throw (err);
        }
        scientistsText = JSON.parse(scientistsText);
        totalScientistsSaved = 0;
        allMongo.numberOfScientists = scientistsText.length;
        for (var i = 0; i < scientistsText.length; i++) {
            insertScientist(scientistsText[i], response);
        }
    });
};

module.exports = allMongo;

Another query

Don't forget to open a terminal and type mongo to start the mongo shell. Then do something like this:

show dbs
use test
show collections
db.scientists.find()
db.scientists.find({} , {_id: 0, firstName: 1, lastName: 1})

Valid Scientists

Save in the root of your project as ValidScientists.json

[
    {
        "_id": "5577c95032fa23f82013611e",
        "firstName": "Albert",
        "lastName": "Einstein",
        "subject": "Physics",
        "__v": 0,
        "comments": [
            {
                "commentText": "Albert One",
                "_id": "5575a4be8ee728bc0da40c49",
                "date": "2015-06-08T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Foobar",
            "Able",
            "Tuna"
        ]
    },
    {
        "_id": "5577c95032fa23f82013611f",
        "firstName": "Rene",
        "lastName": "Descartes",
        "subject": "Radioactivity",
        "__v": 0,
        "comments": [
            {
                "commentText": "Fred",
                "_id": "5574be8c7c93a1180729f3b5",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Suzy",
                "_id": "5574bf42d525507c0ca48e21",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Lunches",
                "_id": "5574bfaed525507c0ca48e22",
                "date": "2015-06-07T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Rene"
        ]
    },
    {
        "_id": "5577c95032fa23f820136121",
        "firstName": "Niels",
        "lastName": "Bohr",
        "subject": "Physics",
        "__v": 0,
        "comments": [
            {
                "commentText": "Niels One",
                "_id": "5575a4af8ee728bc0da40c48",
                "date": "2015-06-08T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Math"
        ]
    },
    {
        "_id": "5577c95032fa23f820136124",
        "firstName": "Thomas",
        "lastName": "Edison",
        "subject": "Radioactivity",
        "__v": 0,
        "comments": [
            {
                "commentText": "Sam",
                "_id": "5574b6dee5c7ed30124b0dca",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Fred",
                "_id": "5574b6f3e5c7ed30124b0dcb",
                "date": "2015-06-07T00:00:00.000Z"
            }
        ],
        "subjects": [
            "asf"
        ]
    },
    {
        "_id": "5577c95032fa23f820136126",
        "firstName": "Johanes",
        "lastName": "Kepler",
        "subject": "Astronomy",
        "__v": 2,
        "comments": [
            {
                "commentText": "Hello Johannes",
                "_id": "55746faa82492e4815d893c4",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Foobar",
                "_id": "557490926f35aa301a50422a",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "_id": "55749e924c3a43000acf589d",
                "commentText": "Fable",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Qux",
                "_id": "55749ebd4c3a43000acf589f",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "_id": "55749f804c3a43000acf58a0",
                "commentText": "Fingers",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Sam",
                "_id": "5574b5597d70f4e813d01ec4",
                "date": "2015-06-07T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Johan",
            "Able"
        ]
    },
    {
        "_id": "5577c95032fa23f820136125",
        "firstName": "Isaac",
        "lastName": "Newton",
        "subject": "Astronomy",
        "__v": 0,
        "comments": [
            {
                "commentText": "Fig",
                "_id": "5574bdf631bd81a416bd855f",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Qux",
                "_id": "5574be373956c08c12f1731c",
                "date": "2015-06-07T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Bar"
        ]
    },
    {
        "_id": "5577c95032fa23f820136122",
        "firstName": "Marie",
        "lastName": "Curie",
        "subject": "Radioactivity",
        "__v": 0,
        "comments": [
            {
                "commentText": "MarieOne",
                "_id": "5574e4ff748448b40c26a324",
                "date": "2015-06-08T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Foo",
            "Bar",
            "Qux",
            "Goober"
        ]
    },
    {
        "_id": "5577c95032fa23f820136123",
        "firstName": "Maxi",
        "lastName": "Planck",
        "subject": "Radioactivity",
        "__v": 0,
        "comments": [
            {
                "commentText": "Foo",
                "_id": "5574bd333a9db45405200d7b",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Bar",
                "_id": "5574bd3a3a9db45405200d7c",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Tom",
                "_id": "5574bd4f3a9db45405200d7d",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Sue",
                "_id": "5574bd861cc805b81ab0427c",
                "date": "2015-06-07T00:00:00.000Z"
            }
        ],
        "subjects": [
            "asdf",
            "Bar"
        ]
    },
    {
        "_id": "5577c95032fa23f82013611d",
        "firstName": "Carl",
        "lastName": "Sagan",
        "subject": "Radioactivity",
        "__v": 1,
        "comments": [
            {
                "_id": "5574a552583c8a0005366cd9",
                "commentText": "Carlbar",
                "date": "2015-06-07T00:00:00.000Z"
            },
            {
                "commentText": "Foo",
                "_id": "5577cd7698d1b48420a76be0",
                "date": "2015-06-10T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Astronomy"
        ]
    },
    {
        "_id": "5577c95032fa23f820136120",
        "firstName": "Nikola",
        "lastName": "Tesla",
        "subject": "Radioactivity",
        "__v": 0,
        "comments": [
            {
                "commentText": "One",
                "_id": "5574e4eb748448b40c26a323",
                "date": "2015-06-08T00:00:00.000Z"
            }
        ],
        "subjects": [
            "Serbia",
            "Electricity",
            "Physics",
            "Blink"
        ]
    },
    {
        "_id": "55786da8c446f6fc4a5d423a",
        "firstName": "Gregor",
        "lastName": "Mendel",
        "subject": "Physics",
        "__v": 0,
        "comments": [],
        "subjects": [
            "Genetics",
            "Plants"
        ]
    }
]

Turn it in

Push you code to your repository, and when you turn it in tell me the branch and folder where it resides.

Additional Notes

Things to remember.

Mongoose Basics Connect

After you run grunt check, run your tests and your program again to make sure everything still works!

This was my bug not yours, so you will not lose points for this. Nevertheless, for the final, be sure that you write the following in routes/connect.js:

connect.connected = true;

This is about lines 14 and 35.

The assignment now has the right code.

Mongoose Basics Empty Collection

Notice that emptyCollection has now changed and contains a check to make sure you are connected. The assignment now has the right code.

Match get and post

Here we do a get on the client:

var jqxhr = $.get(insertUrl, function(result) { ... })

Here is the server side, which is also a get:

router.get('/insertValidCollection', function(request, response) { ... })

If you do a get on the client, do a get on the server. Don't do a get in one place and post in the other. (I had this mixed up in one version of the assignment. You need to get this cleaned up if you followed my example and made a mistake.)

Scientists File

Be sure to add the code to ignore scientists.