MVC: My struggle and path to enlightenment

Flashback

invented in 1979
by Trygve Reenskaug
while with Xerox
NOT FOR THE WEB
for GUI applications
with Smalltalk - 80

By Trygve Reenskaug - Trygve Reenskaug, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31168223

Smalltalk GUI

MVC for each element on the screen!!!

A Thing

According to Trygve Reenskaug

Something that is of interest to the user. It could be concrete, like a house or an integrated

circuit. It could be abstract, like a new idea or opinions about a paper. It could be a whole,

like a computer, or a part, like a circuit element

Model

According to Trygve Reenskaug

Models represent knowledge. A model could be a single object (rather uninteresting), or it

could be some structure of objects.

A Model is an active representation of an abstraction in the form of data in a computing

system

View

According to Trygve Reenskaug

A view is attached to its model (or model part) and gets the data necessary for the presentation

from the model by asking questions...

To any given Model there is attached one or more Views, each View being capable of

showing one or more pictorial representations of the Model on the screen and on hardcopy.

... the view will therefore have to know the semantics of the attributes of the model it represents.

Editors

Controllers

According to Trygve Reenskaug

A controller is the link between a user and the system. It provides the user with input by

arranging for relevant views to present themselves in appropriate places on the screen. It

provides means for user output by presenting the user with menus or other means of giving

commands and data.

A controller should never supplement the views...

Conversely, a view should never know about user input, such as mouse operations and

keystrokes.

MVC

Let's see how this works on the Web

Controllers

According to PHP frameworks

Matches a route
Instantiates a class that groups actions
Calls an action with parameters
The action calls stuff on model
The action creates a view
The action gives model to view
The actions renders the view

... so many of them, doing the exact same thing ...

Model

The model is your database
The model is where all your DB queries reside
For each table in your DB you have a model

According to friends and random search results

Model

According to Laravel

Defining Models
- Eloquent Model Conventions
Retrieving Models
Retrieving Single Models / Aggregates
Inserting & Updating Models
Deleting Models
Query Scopes
Events
- retrieved, creating, created, updating, updated, saving, saved, deleting, deleted, restoring, restored

Model

According to Yii 2.0

Attributes
Scenarios
Validation Rules
Massive assignment
Data Exporting

What annoys me

thin models (they are just DBAL)
fat controllers (this is where the actual work is done)
this is bad
because now we can't reuse our logic

A calculator App

No data -> no DB -> no Model ???
Have the calculations done in the controller?
Use an HTTP controller in a command line app?

Separation of concerns

Different controllers for different inputs
Different view for different presentations and views
Same calculator logic

Implementation

... next time :)

Enlightenment

Enlightenment (to an extent)

Thank you!

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