rdd-technical-reference.md



title:  'SUB RDD Technical Reference'


About this Document
Author: Software Quality Working Group


Audience: Developers of the Research and Development Department of the Göttingen State and University Library.


Purpose: This guideline should help you getting started a new software development project (or improving an existing one!) in the Research and Development Department of the Göttingen State and University Library.
Our goal is to establish better software quality by following standards the developer team has mutually agreed upon. Roughly basing on the EURISE Network Technical Reference, these standards are discussed, worked out, and decided in the Software Quality Working Group, which meets biweekly on Tuesdays at 13:00--14:00. However, they aren't cast in stone, so in case you have a good idea for a better standard, feel free to contribute!


Status: This document is a living document and will be extended as soon as the Software Quality Working Group has agreed upon a new standard for software projects in RDD.
TODOs and addenda of this document are maintained here.

Style Guides

General
The basic definitions are given by our EditorConfig file, .editorconfig,
i.e. Unix line breaks and 2 space indentation.

Specific for Programming Languages
For the more prominent programming languages we have formatting and general style guides we ask you to follow:


Java: The Java style guide can be found here. It's based on the Google style guide for Java with some minor RDD specific settings. You can configure Eclipse to use it automatically at Eclipse > Preferences > Java > Code Style > Formatter. Just load the RDD Eclipse Java Google Style in the formatter preferences and use it in your RDD projects.


JavaScript: For JS we use the Airbnb JavaScript Style Guide.


HTML/CSS: For HTML/CSS we agreed upon the Google HTML/CSS Style Guide.


XQuery: We use the xqdoc style guide with the following addenda:

use double quotes instead of single quotes (for easy escaping)
use four spaces for a TAB (because eXide switching the preferences in eXide's setting isn't permanent)


XSLT: Since there is no official style guide for XSLT, we decided to write
our own, resulting from common best practices and own experiences within
the department.


Python: For Python PEP 8 should be used, Django has a style guide based on PEP-8 with some exceptions: Django-Styleguide. There are linters and tools like flake-8 and pep-8 available as support.


SPARQL: For SPARQL there is not really any official style guide and there is no possibility to simply include any code style automatically using a code style file. We just collect some advice how to format and use SPARQL code here.


Is Your Software Fully Documented?

Doc Sprints
To ensure the best documentation of our code we meet on a weekly base for a code sprint to document everything we have coded throughout the week and haven't been able to document properly yet. The meeting takes place in the meeting room at 1pm. Cookies may be provided.

General


Don't document a language's specifics, e.g. operators.

Example: Use of => in the XQuery expression replace("qbc", "q", "b") => substring(1, 2) MUST NOT be explained in a comment.


It is best to use a language's structure to document.


Write the best documentation you can.


Documentation and variable language is American English.


Docs should be as close to the code as possible.

This refers both to the documentation in a repository and in the code itself, e.g. inline documentation.


Every code repository MUST have:

a README.md file according to this template that contains

link to original repository (if the software is forked or otherwise based on preexisting software)
short introduction on what the repository is about
a guide how to get the software running (if makes sense)
link to demo instance
example or demo installation
link to license file
contribution guide
link to style guide
link to bug tracker/project management system
known issues
badges to CI status


a LICENSE file


Developer Documentation

Architecture of the Software
Each software project should be documented using an architecture diagram that helps understanding its basic functionality (even though using tools to generate diagrams such as UML class diagrams doesn't seem to be possible in every case).\
Examples:

Generating call graphs in eXist-db

Call diagrams can be useful to follow code and service calls and should be existing for every API method.

API Documentation


The docs should comprise used parameters, author and @since annotations


Example for Java


Links to callers must not be listed in the documentation, because this info will be deprecated soon. It is strongly recommended to use call stacks of tools like Eclipse (Java) and/or Call Graph Module (SADE).


Document REST-APIs using openAPI if possible. OpenAPI docs should be located at /doc/api on servers.


Admin Documentation

The docs should comprise how to install the software, how to run and/or restart it, how to test the installation, ...


Server documentation:
This type of documentation is provided and maintained in our DARIAH wiki space.\
We have a template encompassing all information necessary: To create a wiki page for a new server navigate to the FE Server list, select "..." right beside the "Create" button and search for "FE-Server".

User Documentation


how to use the software and APIs, FAQs, walkthroughs, ...


guided tour (Bootstrap Tour) as user documentation

for SADE portal usage (such as Fontane, BdN, Architrave)
for complex Digital Editions


screencasts


CESSDA's Software Maturity Levels in RDD

Which version control do you use? You do use version control, do you?
We exclusively use git in RDD. Please see https://git-scm.com/doc for information on how it works.
We recommend to use the Git flow Workflow (also consult the Cheat Sheet).
For git flow it is safest to protect your master and develop branch on server side to avoid accidental pushes into these branches. All specific branches working on an issue described in a bug tracker may utilize the following naming scheme:


[track]/#[ISSUENUMBER]-[KEYWORD]


e.g. bugfix/#12-flux-capacitor.
A GitHub workflow used in DARIAH-DE and related services is described in the DARIAH-DE Wiki.
You could also use the GitLab flow as a simpler alternative, which can be broken down into 11 Rules.
It is also recommended to automatically close issues via commit message; How this works exactly depends on the Git repository server. Issues can also be referenced across repositories.
We use the following Git servers at the moment in RDD:

Projects (GWDG) --> https://projects.gwdg.de

GitLab (GWDG) --> https://gitlab.gwdg.de

github.org --> https://github.com/subugoe


Which one is suitable for you depends on:

the project you are working on
existing code
whether or not you want to use CI/CD or GitLab Runners
...

We have got an RDD team on GitHub. Feel free to join us!
Consider mirroring of repos for project visibility (e.g. mirror GitLab/Projects code to Github?)

Do you track your bugs properly?
A bug tracking system is obligatory! Please use the respective bug tracking system of your repo and/or project management solution (please see chapter version control)!

Do you test your software?
We aim to have a test coverage of 100% (except for getter and setter methods). This is understood on a component level, which means that every method should have at least one test. Whether you achieve this by Test Driven Development (TDD) or not is specific to your preferred way to work.
Please keep in mind not only to write a test for each of your functions but also
to consider all possible outcomes. It is e.g. not sufficient to test if a function
creates a file if the written content depends on variables etc.
Examples for writing tests in different programming languages are:

XQuery