Welcome to NYC Sinatra!

Introduction

We're going to build a history site for New York City, so we're going to need to create the following database structure:

• You will have three models (and their corresponding tables) Landmark, Title, Figure (think historical figure).
• A landmark belongs_to a figure and a figure has_many landmarks.
• Titles and figures have a "many-to-many" relationship, so we'll need a join table.

Domain Model

Our client has decided that the history app we're building them should have a special focus on historical figures. For this reason, it is through figure views and controllers that most of the magic of our app will happen. Our app will have view pages for all of the landmarks and a user will be able to create a new landmark. BUT, when a user creates or edits a figure, they should also be able to select or create a new landmark and/or title to associate to that figure. In other words, the form for a new figure and the form to edit a figure should allow the user to select from existing landmarks and title and create new landmarks and titles to associate to the figure. Our client doesn't really care about titles, on the other hand, and we won't be required to build a titles controller or to have any titles views. New titles will only get created in the context of creating or editing a figure.

Instructions

Migrations

Write migrations to create the following tables:

Figures

id	name
1	Robert Moses
2	Al Smith
3	Theodore Roosevelt
4	Peter Stuyvesant
5	Boss Tweed
6	Michael Bloomberg
7	Ed Koch
8	Fiorello LaGuardia
9	Jimmy Walker
10	Belle Moskowitz

Landmarks

id	name	figure_id	year_completed
1	BQE	1	1947
2	Holland Tunnel	5	1927
3	Wall Street Wall	4	1684
4	Brooklyn Battery Tunnel	10	1973

Titles

id	name
1	Mayor
2	President
3	Governor
4	NYC Parks commissioner

Join Tables

Any time you have a has_many to has_many relationship, you'll need to create a join table. An example of a has_many to has_many relationship is titles and figures. A title has_many figures because many people hold a title over time and a figure usually has_many titles over their career.

Below is an example of a join table. We called it figure_titles and you should do the same for this lab.

Figure_titles

id	title_id	figure_id
1	3	2
2	3	3
3	2	3
4	1	9
5	4	1

Models

Now, use the has_many, belongs_to and has_many, :through macros to set up the correct associations in your models:

• A Landmark belongs_to a figure and a figure has_many landmarks.
• A title has_many figure_titles and many figures through figure_titles.
• A figure has_many figure_titles and many titles through figure_titles.
• A figure_title belongs_to a figure and a title.

Top-Tip: Type tux in your terminal in the directory of this project in order to drop into an interactive Ruby console that is connected to your models and database. Here, you can play around with creating and associating instances of the classes you create once you properly set up the above. This is a helpful way to solidify your understanding of the relationships between your models before you go into building the routes, views and forms that will allows your users to interact with them. Start out by creating a new figure, landmark and title. Then, add that landmark and title to the figures collection of landmarks and titles respectively. Keep playing around from there however you like.

Test Database Migration

Make sure to migrate your test database by running rake db:migrate SINATRA_ENV=test

Views and Controllers

You should create a Landmarks Controller and a Figures Controller. This lab is test-driven and will also require you to think outside the box to get things working.

Your forms will need to be complex. Your form for a new figure should dynamically generate checkboxes out of the available landmarks and titles. It should also have fields for creating a new landmark and/or a new title. The controller action that catches the POST request sent by submitting this form should account for this. The same is true of your form for editing a given figure. Read the tests very carefully to understand how you should set up your forms.

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View Sinatra NYC on Learn.co and start learning to code for free.