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# Coding Standards

## Code Style

Please observe the following coding standards when working on the codebase:

- Docstrings quoted with `"""`

- Simple strings in source code should be quoted with `'`

- Coding must follow a style guide. In case of Python it is pep8 and using the command line tool pep8 (or `make pep8`) to enforce this. The pep8 checks E121-E128 have been disabled until pep8 version 1.3 becomes widely available.

- Python documentation guide

- Comments should be complete sentences. If a comment is a phrase or sentence, its first word should be capitalized, unless it is an identifier that begins with a lower case letter (never alter the case of identifiers!). Comments should start with a # and a single space.

- Adherence to regression/unit testing wherever possible (`make test`)

- Use of github for revision control, issue tracking and management

- Simple deployment procedure - all dependencies must be delivered with the plugin installer for QGIS or exist in standard QGIS installs.

- Develop in the spirit of XP/Agile, i.e. frequent releases, continuous integration and iterative development. The master branch should always be assumed to represent a working demo with all tests passing.

- All strings should be internationalisation enabled. Please see Internationalisation Support for details.

- Code must pass a pylint validation (http://www.logilab.org/card/pylint_manual#what-is-pylint). You can test this using the make target `make pylint`. In some cases you may wish to override a line or group of lines so that they are not validated by lint. You can do this by adding either:

      import foo  # pylint: disable=W1203

  or:

      # pylint: disable=W1234
      print 'hello'
      print 'goodbye'
      # pylint: enable=W1234

  The relevant id (W1234) is provided on the output of the above mentioned lint command’s output. A complete list of codes is available at http://pylint-messages.wikidot.com/all-codes.

  Note

  You can globally ignore messages by adding them to `pylintrc` in the `[MESSAGES CONTROL]` section.

  The following pylint messages have been thus globally excluded from the check. For a discussion of these see also github issue https://github.com/AIFDR/inasafe/issues/245.

  - All type R: Refactor suggestions such as limiting the number of local

      variables. We may bring some back later.

  - All type I: Information only

  - W0142: Allow the Python feature F(*args, **kwargs)

  - W0201: Allow definition of class attributes outside the constructor.

  - W0212: Allow access to protected members (e.g. _show_system_info)

  - W0231: Allow classes without constructors.

  - W0232: Un-instantiated classes is a feature used in this project.

  - W0403: Relative imports are OK for modules that live in the same dir

  - W0511: Appearance of TODO and FIXME is not a sign of poor quality

  - E1101: Disable check for missing attributes.

  - E1103: This one does not understand numpy variables.

  - C0103: Allow mathematical variables such as x0 or A.

  - C0111: Allow missing docstrings in some cases

  - C0302: No restriction on the number of lines per module

  It is of course possible to run all pylint checks on any part of the code if desired: E.g pylint safe/storage/raster.py

- Each source file should include a standard header containing copyright, authorship and version metadata as shown in the exampled below.

Example standard header:

    # -*- coding: utf-8 -*-
    """**One line description.**

    .. tip::
       Detailed multi-paragraph description...

    """

    __author__ = 'Ole Nielsen <ole.moller.nielsen@gmail.com>'
    __revision__ = '$Format:%H$'
    __date__ = '01/11/2010'
    __license__ = "GPL"
    __copyright__ = 'Copyright 2012, Australia Indonesia Facility for '
    __copyright__ += 'Disaster Reduction'

Note

Please see How did you embed the git version SHA1 into each .py file? for details on how the revision tag is replaced with the SHA1 for the file when the release packages are made.

### Doc strings

All code should be self documenting. We used the following style for documenting functions and class methods:

    def setKeywordDbPath(self, thePath):
        """Set the path for the keyword database (sqlite).

        The file will be used to search for keywords for non local datasets.

        Args:
            * thePath: a valid path to a sqlite database. The database does
                  not need to exist already, but the user should be able to write
                  to the path provided.
        Returns:
            None
        Raises:
            None
        """
        self.keywordDbPath = str(thePath)

- If you use a few lines of code in more than one place, refactor them into their own function.
- If you use a literal string or expression in more than one place, refactor it into a function or variable.

Various other sphinx markup elements may be used in the docstrings too. For more information see also: http://thomas-cokelaer.info/tutorials/sphinx/docstring_python.html

### Human Interface Guidelines

For consistency of user experience, the user interfaces created in Risk in a Box should adhere to the QGIS Human Interface Guidelines (HIG) which are listed here for your convenience:

- Group related elements using group boxes: Try to identify elements that can be grouped together and then use group boxes with a label to identify the topic of that group. Avoid using group boxes with only a single widget / item inside.
- Capitalise first letter only in labels: Labels (and group box labels) should be written as a phrase with leading capital letter, and all remaing words written with lower case first letters
- Do not end labels for widgets or group boxes with a colon: Adding a colon causes visual noise and does not impart additional meaning, so don’t use them. An exception to this rule is when you have two labels next to each other e.g.: Label1 [Plugin Path:] Label2 [/path/to/plugins]
- Keep harmful actions away from harmless ones: If you have actions for ‘delete’, ‘remove’ etc, try to impose adequate space between the harmful action and innocuous actions so that the users is less likely to inadvertantly click on the harmful action.
- Always use a QButtonBox for ‘OK’, ‘Cancel’ etc buttons: Using a button box will ensure that the order of ‘OK’ and ‘Cancel’ etc, buttons is consistent with the operating system / locale / desktop environment that the user is using.
- Tabs should not be nested. If you use tabs, follow the style of the tabs used in QgsVectorLayerProperties / QgsProjectProperties etc. i.e. tabs at top with icons at 22x22.
- Widget stacks should be avoided if at all possible. They cause problems with layouts and inexplicable (to the user) resizing of dialogs to accommodate widgets that are not visible.
- Try to avoid technical terms and rather use a laymans equivalent e.g. use the word ‘Transparency’ rather than ‘Alpha Channel’ (contrived example), ‘Text’ instead of ‘String’ and so on.
- Use consistent iconography. If you need an icon or icon elements, please contact Robert Szczepanek on the mailing list for assistance.
- Place long lists of widgets into scroll boxes. No dialog should exceed 580 pixels in height and 1000 pixels in width.
- Separate advanced options from basic ones. Novice users should be able to quickly access the items needed for basic activities without needing to concern themselves with complexity of advanced features. Advanced features should either be located below a dividing line, or placed onto a separate tab.
- Don’t add options for the sake of having lots of options. Strive to keep the user interface minimalistic and use sensible defaults.
- If clicking a button will spawn a new dialog, an ellipsis (...) should be suffixed to the button text.

### Code statistics

- https://www.ohloh.net/p/inasafe/analyses/latest
- https://github.com/AIFDR/inasafe/network
- https://github.com/AIFDR/inasafe/graphs

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