Patterns #

Why? 🤔 #

Why do we care about patterns and why do we want to study them?

Universe #

In the space and time there is matter and energy.

Universe: Diagram of the universe objects and classes

Senses #

Inside that Universe there are living beings that have the ability to perceive external and internal physical stimulations through certain organs which are passed to our nervous system:

• Sight
• Hearing
• Smell
• Taste
• Touch

Physical signals that can vary in their frequency, width, ... and transform in different color values decomposed into combinations of red, green and blue or different values of words decomposed into phonemes, a, ae, e, i, o , u, ... depending on the language.

Light spectrum

Measurement units #

Basic units

Derived units

Names

Relations

What? 🤓 #

What is a pattern?

Pattern, model that is used to get an equal thing

Pattern for an artisan and in industry:

Pattern in science:

Equality #

For what? 😲 #

For what do we need patterns?

To be able to, from the present, study the past and predict/imagine the future.

How? 🧐 #

How are patterns? How do we find them in our universe?

Pattern types #

Recurrent #

It will eventually repeat. Example of recurrent pattern would be the rain. You don't know when but it will eventually rain at some point.

Iterative #

It repeats, the end of one iteration directly connects with the beginning of a new one. Example of an iterative pattern would be day and night.

Recursive #

It repeats in itself. You can amplify or reduce its point of view and it will replicate the same structure.

Recursion everywhere #

We can find examples of recursion in nature

Caracola

Brocoli

In our daily life

Family tree

In art

Katsushika Hokusai

Simple Patterns #

Line	Three points	Circle
Sequence	Alternation	Circularity
Line of time	Water molecule, mountains	Cells, soap bubbles
Metro line	Pyramids	Hurricanes
natural or artificial frontier, line of products...	Social organizations, economy...	Roundabouts, vicious and virtuous circles

Patterns in software 🖥 #

Graphical User Interface #

Line	Three points	Circle
Form	Window with panels	Navigation map

Data types #

Data structures #

Line	Three points	Circle
List	Tree, Hierarchy	Graph

Flow control sentences #

{
 console.log("Title");
 console.log("Subtitle");
 ...
}

if (x > 0) {
  ...
} else {
  ...
}

switch (x){
  case 0:
  ...
  break;
}

while (x > 0) {
 ...
}

do {
 ...
} while (x > 0);

Development methodologies #

Line	Three points	Circle
Waterfall	Crystal Clear	Iteratives

Domain model 👌🏼 #

The domain model describes the most important concepts (types of objects) of a context, things like objects from the domain and the relations between them.

• Business objects that represent things that are manipulated by the business.
• Real world objects and concepts which a system has to keep track of.
• Events that will or have already occur.

With the objective of

• Comprehend the structure and dynamics of the organization in which the system will be developed.
• Comprehend the latest problems of the target organization.
• Ensure that clients, final users and developers have a common comprehension of the target organization.
• Obtain the requirements of the system to help the target organization.

Unified Model Language #

The usage of UML (Unified Model Language) is recommended to model the domain. RUP (Rational Unified Process) already does so.

Each symbol (lexical) related (syntax) in a diagram has a standard meaning (semantics). We avoid ambiguity and different people interpret the same from the same diagram, opposed to non standardized arrows and boxes.

Structural diagrams #

Objects diagram	Classes diagram
Picture (static) of entities from reality	Picture (static) of classes of entities from reality
Barely used	Extremely used

Behavioral diagrams #

Activity diagram	State diagram
Video (dynamic) with sequence of highlighted actions	Video (dynamic) with sequence of NOT highlighted actions, highlighting in-between states
Barely used	Extremely used

Sequence diagram	Collaboration diagram
Video (dynamic) with sequence of actions between different collaborators	Picture (static) without sequence of actions between different collaborators
Barely used	Extremely used

Domain Model conclusions #

• Comprehend the context of a system with crucial knowledge about use cases.
• Define a common vocabulary for users, clients, developers and others involved.
  • Glossary of keywords.
  • Consistent mix of all participants' language.
  • Suggest internal classes during analysis.