diff --git a/flake8/formatting/base.py b/flake8/formatting/base.py new file mode 100644 index 0000000..85a931c --- /dev/null +++ b/flake8/formatting/base.py @@ -0,0 +1,105 @@ +"""The base class and interface for all formatting plugins.""" +from __future__ import print_function + + +class BaseFormatter(object): + """Class defining the formatter interface. + + .. attribute:: options + + The options parsed from both configuration files and the command-line. + + .. attribute:: filename + + If specified by the user, the path to store the results of the run. + + .. attribute:: output_fd + + Initialized when the :meth:`start` is called. This will be a file + object opened for writing. + + .. attribute:: newline + + The string to add to the end of a line. This is only used when the + output filename has been specified. + """ + + def __init__(self, options): + """Initialize with the options parsed from config and cli. + + This also calls a hook, :meth:`after_init`, so subclasses do not need + to call super to call this method. + + :param optparse.Values options: + User specified configuration parsed from both configuration files + and the command-line interface. + """ + self.options = options + self.filename = options.output_file + self.output_fd = None + self.newline = '\n' + self.after_init() + + def after_init(self): + """Initialize the formatter further.""" + pass + + def start(self): + """Prepare the formatter to receive input. + + This defaults to initializing :attr:`output_fd` if :attr:`filename` + """ + if self.filename: + self.output_fd = open(self.filename, 'w') + + def handle(self, error): + """Handle an error reported by Flake8. + + This defaults to calling :meth:`format` and then :meth:`write`. To + extend how errors are handled, override this method. + + :param error: + This will be an instance of :class:`~flake8.style_guide.Error`. + :type error: + flake8.style_guide.Error + """ + line = self.format(error) + self.write(line) + + def format(self, error): + """Format an error reported by Flake8. + + This method **must** be implemented by subclasses. + + :param error: + This will be an instance of :class:`~flake8.style_guide.Error`. + :type error: + flake8.style_guide.Error + :returns: + The formatted error string. + :rtype: + str + """ + raise NotImplementedError('Subclass of BaseFormatter did not implement' + ' format.') + + def write(self, line): + """Write the line either to the output file or stdout. + + This handles deciding whether to write to a file or print to standard + out for subclasses. Override this if you want behaviour that differs + from the default. + + :param str line: + The formatted string to print or write. + """ + if self.output_fd is not None: + self.output_fd.write(line + self.newline) + else: + print(self.output_fd) + + def stop(self): + """Clean up after reporting is finished.""" + if self.output_fd is not None: + self.output_fd.close() + self.output_fd = None diff --git a/setup.py b/setup.py index 0b90cf7..00b5a68 100644 --- a/setup.py +++ b/setup.py @@ -58,6 +58,7 @@ setuptools.setup( url="https://gitlab.com/pycqa/flake8", packages=[ "flake8", + "flake8.formatting", "flake8.main", "flake8.options", "flake8.plugins",