- <a href="#how-to-contribute">How to contribute</a>

- <a href="#versioning">Versioning</a>

**To work on a new pattern** you need to do the following steps:

1. If there is no issue for the new pattern yet, raise new issue. Comment on

the issue that you are working on it so that others don't start work on the

same thing.

2. Fork the repository.

3. Create a new folder for the pattern. The rough structure of the new folder would be as follows:

* etc (every resource related to the pattern, like diagrams)

* src (the source code of the pattern)

* index.md (the description of the pattern)

* pom.xml (the maven pom.xml)

4. Implement the code changes in your fork. Remember to add sufficient comments

documenting the implementation. Reference the issue id e.g. #52 in your

commit messages.

5. Format the code according to [Google Java Style Guide](https://google.github.io/styleguide/javaguide.html)

* [Eclipse configuration](https://github.com/google/styleguide/blob/gh-pages/eclipse-java-google-style.xml)

* [IntelliJ configuration](https://github.com/google/styleguide/blob/gh-pages/intellij-java-google-style.xml)

6. Create a simple class diagram from your example code and put it inside of the etc folder.

7. Add description of the pattern in index.md and link to the class diagram.

(Attention, all internal links must be relative to the pattern subdirectory, else the links dont link properly on the website)

8. Create a pull request.

**Structure of the index.md file**

--- # this is so called 'Yaml Front Matter', read up on it here: http://jekyllrb.com/docs/frontmatter/

layout: pattern # layout must allways be pattern

title: Best Pattern Ever # the properly formatted title

folder: best-pattern-ever # the folder name in which this pattern lies

permalink: /patterns/best-pattern-ever/ # the permalink to the pattern, to keep this uniform please stick to /patterns/FOLDER/

categories: creational # categories of the pattern

tags: # tags of the pattern

- best

- ever

- awesome

**Intent:** Makes your code awesome


**Applicability:** Use the Best Pattern Ever pattern when

* you want to be the best

* you need to ...

**Real world examples:**

* [Nowhere](http://no.where.com)

**To add a new category or tag** you need to edit the _config.yml file of the gh-pages branch.

In there you should find 2 yaml lists with the respective names 'category-list' and 'tag-list'

**To work on one of the non-pattern issues** you need to do the following steps:

1. Check that the issue has "help wanted" badge

2. Comment on the issue that you are working on it

3. Fork the repository.

4. Implement the code changes in your fork. Remember to add sufficient comments

documenting the implementation. Reference the issue id e.g. #52 in your

commit messages.

5. Create a pull request.

**For creating/editing UML diagrams** you need [ObjectAid UML Explorer for Eclipse](http://www.objectaid.com/home).

**For inspiration** check out the following sources:

* there is a good list of design patterns at [Wikipedia](http://en.wikipedia.org/wiki/Software_design_pattern)

* Martin Fowler's [Catalog of Patterns of Enterprise Application Architecture](http://martinfowler.com/eaaCatalog/)

* [pattern language for microservices](http://microservices.io/patterns/index.html)

* Microsoft's [Cloud Design Patterns](http://download.microsoft.com/download/B/B/6/BB69622C-AB5D-4D5F-9A12-B81B952C1169/CloudDesignPatternsBook-PDF.pdf)

**Links to patterns applied in real world applications** are welcome. The links

should be added to the corresponding section of the `index.md`.

Java-design-patterns project uses [semantic versioning](http://semver.org/)

scheme. However, version numbers in this project do not signify binary releases

(since we don't make any) but rather milestones achieved on the roadmap. In

other words, version numbers are used only for project planning sake.