Another week has flown past!  Last week we learnt a few essential concepts and I also had a few ideas about the type of problems I would like to solve.  We did a bunch of work on authentication and authorisation.

Working on authentication was fascinating.  So when you have an app you obviously would like to customize the experience for your users, which means you need to identify and recognize them.  The easiest way to do this is by getting users to register and choose a password.

Here is an example of a Registration page asking for a password and confirmation

But having users passwords in your database without encryption is a bad idea. Since most people tend to use the same password for many services.  Therefore it is better to encrypt the password, but if you use an encryption service that can be decrypted, somebody can still use the encrypted value you store to get the original password.

The answer to this is to use one-way encryption that is consistent. This means it cannot be decrypted, but every time the same password is encrypted the result is the same so you can compare the encrypted versions to see if they match. Like many other features that most apps use, there is a gem to help in rails. Which once again, makes the whole process a breeze.

Once registered a new user can just log in for future visits

Now you would think that when choosing which encryption method to use, you would want something difficult to crack but that can still do its work as quickly as possible;  but it turns out you actually want one that is slow, which makes it harder to brute force it.  This article on How to safely store a password explains it in detail.  So we ended up using bcrypt.

This next step after authenticating users, involves deciding who should have access to which services in your app.  Once again something that rails makes very easy!

I think The Starter League has done an awesome job so far with the curriculum, it feels like they introduce us to the right concept at the right time in the right dose.  They also leave enough for us to figure out on our own. This week Jeff the Chief Instructor at Starter League shared this video that shows a little of the teaching methodology that they try and follow:

It was another great week, it was fun learning about authentication and authorisation. I have also spent a great deal of time this week thinking about the problems I would like to solve, and will do another post about that.

I am now 5 weeks into The Starter League and I still love every minute of it.  At times I find it hard to believe that it has only been 3 weeks since I worked with Rails for the first time.  It has empowered me to do things already that I thought would be impossible after only 5 weeks here.

In the last two weeks we have spent a lot of time working with databases.  First we’ve learnt how to make two databases relate to each other by adding a foreign key to one of them.  You call that one to many relationships, since you have one ‘object’ that relates to many others.

The list of Movies on our SMDB app – our own IMDB clone

To explain this concept and give us something to work on, Raghu made us build a copy of IMDB (Internet Movie Database). For the sake of our project, we assumed a movie could only have one director.  So one director could have many movies but a movie could only have one director. This was our first one to many relational databases.  We achieved this by adding a director_id column to the movie table in our database…. that sentence would have made no sense to me a month ago!

We then added another one to many relationship by adding roles to a movie (again assuming a role could only be in one movie).  But since a role is played by an actor, we could add another one to many relationship between a role and an actor.

The details page of my Favourite movie, The Shawshank Redemption on our IMDB clone

After we did that, Raghu explained that we in effect had created a many to many relationship between actors and movies by using a table linking the two, in this case called roles.  So we had created our first many to many relationship without even knowing it!

Raghu also challenged us to build a paging system after one of the classes this week.  I struggled with that one for a few hours but eventually I was able to get pagination going the way I wanted it without using a gem. A gem is like plugin, a piece of code somebody else wrote, usually for a task that many people want done. You install the gem and then you can use it instead of writing that part of the code yourself.

Doing pagination far a fun challenge, here it is nicely implemented on our IMDB clone

On Friday we’ve also learnt about font awesome, another little arrow now in our arsenal.  It allows you to add icons to your site that act like fonts, so you can change the colour, size and some other properties in CSS like regular fonts.  No need for a designer to redo everything a 100 times!

Building a IMDB clone was great fun! I continue to be amazed how much fun it is learning to code. I really look forward to using these new skills to solve meaningful problems in the future!