Source code for invoke.collection

import copy
import types

from .util import six, Lexicon, helpline

from .config import merge_dicts, copy_dict
from .parser import Context as ParserContext
from .tasks import Task

[docs]class Collection(object): """ A collection of executable tasks. See :doc:`/concepts/namespaces`. .. versionadded:: 1.0 """ def __init__(self, *args, **kwargs): """ Create a new task collection/namespace. `.Collection` offers a set of methods for building a collection of tasks from scratch, plus a convenient constructor wrapping said API. In either case: * The first positional argument may be a string, which (if given) is used as the collection's default name when performing namespace lookups; * A ``loaded_from`` keyword argument may be given, which sets metadata indicating the filesystem path the collection was loaded from. This is used as a guide when loading per-project :ref:`configuration files <config-hierarchy>`. * An ``auto_dash_names`` kwarg may be given, controlling whether task and collection names have underscores turned to dashes in most cases; it defaults to ``True`` but may be set to ``False`` to disable. The CLI machinery will pass in the value of the ``tasks.auto_dash_names`` config value to this kwarg. **The method approach** May initialize with no arguments and use methods (e.g. `.add_task`/`.add_collection`) to insert objects:: c = Collection() c.add_task(some_task) If an initial string argument is given, it is used as the default name for this collection, should it be inserted into another collection as a sub-namespace:: docs = Collection('docs') docs.add_task(doc_task) ns = Collection() ns.add_task(top_level_task) ns.add_collection(docs) # Valid identifiers are now 'top_level_task' and 'docs.doc_task' # (assuming the task objects were actually named the same as the # variables we're using :)) For details, see the API docs for the rest of the class. **The constructor approach** All ``*args`` given to `.Collection` (besides the abovementioned optional positional 'name' argument and ``loaded_from`` kwarg) are expected to be `.Task` or `.Collection` instances which will be passed to `.add_task`/`.add_collection` as appropriate. Module objects are also valid (as they are for `.add_collection`). For example, the below snippet results in the same two task identifiers as the one above:: ns = Collection(top_level_task, Collection('docs', doc_task)) If any ``**kwargs`` are given, the keywords are used as the initial name arguments for the respective values:: ns = Collection( top_level_task=some_other_task, docs=Collection(doc_task) ) That's exactly equivalent to:: docs = Collection(doc_task) ns = Collection() ns.add_task(some_other_task, 'top_level_task') ns.add_collection(docs, 'docs') See individual methods' API docs for details. """ # Initialize self.tasks = Lexicon() self.collections = Lexicon() self.default = None = None self._configuration = {} # Specific kwargs if applicable self.loaded_from = kwargs.pop("loaded_from", None) self.auto_dash_names = kwargs.pop("auto_dash_names", None) # splat-kwargs version of default value (auto_dash_names=True) if self.auto_dash_names is None: self.auto_dash_names = True # Name if applicable args = list(args) if args and isinstance(args[0], six.string_types): = self.transform(args.pop(0)) # Dispatch args/kwargs for arg in args: self._add_object(arg) # Dispatch kwargs for name, obj in six.iteritems(kwargs): self._add_object(obj, name) def _add_object(self, obj, name=None): if isinstance(obj, Task): method = self.add_task elif isinstance(obj, (Collection, types.ModuleType)): method = self.add_collection else: raise TypeError("No idea how to insert {!r}!".format(type(obj))) return method(obj, name=name) def __repr__(self): task_names = list(self.tasks.keys()) collections = ["{}...".format(x) for x in self.collections.keys()] return "<Collection {!r}: {}>".format(, ", ".join(sorted(task_names) + sorted(collections)) ) def __eq__(self, other): return ( == and self.tasks == other.tasks and self.collections == other.collections ) def __ne__(self, other): return not self == other def __nonzero__(self): return self.__bool__() def __bool__(self): return bool(self.task_names)
[docs] @classmethod def from_module( cls, module, name=None, config=None, loaded_from=None, auto_dash_names=None, ): """ Return a new `.Collection` created from ``module``. Inspects ``module`` for any `.Task` instances and adds them to a new `.Collection`, returning it. If any explicit namespace collections exist (named ``ns`` or ``namespace``) a copy of that collection object is preferentially loaded instead. When the implicit/default collection is generated, it will be named after the module's ``__name__`` attribute, or its last dotted section if it's a submodule. (I.e. it should usually map to the actual ``.py`` filename.) Explicitly given collections will only be given that module-derived name if they don't already have a valid ``.name`` attribute. If the module has a docstring (``__doc__``) it is copied onto the resulting `.Collection` (and used for display in help, list etc output.) :param str name: A string, which if given will override any automatically derived collection name (or name set on the module's root namespace, if it has one.) :param dict config: Used to set config options on the newly created `.Collection` before returning it (saving you a call to `.configure`.) If the imported module had a root namespace object, ``config`` is merged on top of it (i.e. overriding any conflicts.) :param str loaded_from: Identical to the same-named kwarg from the regular class constructor - should be the path where the module was found. :param bool auto_dash_names: Identical to the same-named kwarg from the regular class constructor - determines whether emitted names are auto-dashed. .. versionadded:: 1.0 """ module_name = module.__name__.split(".")[-1] def instantiate(obj_name=None): # Explicitly given name wins over root ns name (if applicable), # which wins over actual module name. args = [name or obj_name or module_name] kwargs = dict( loaded_from=loaded_from, auto_dash_names=auto_dash_names ) instance = cls(*args, **kwargs) instance.__doc__ = module.__doc__ return instance # See if the module provides a default NS to use in lieu of creating # our own collection. for candidate in ("ns", "namespace"): obj = getattr(module, candidate, None) if obj and isinstance(obj, Collection): # TODO: make this into Collection.clone() or similar? ret = instantiate( ret.tasks = ret._transform_lexicon(obj.tasks) ret.collections = ret._transform_lexicon(obj.collections) ret.default = ret.transform(obj.default) # Explicitly given config wins over root ns config obj_config = copy_dict(obj._configuration) if config: merge_dicts(obj_config, config) ret._configuration = obj_config return ret # Failing that, make our own collection from the module's tasks. tasks = filter(lambda x: isinstance(x, Task), vars(module).values()) # Again, explicit name wins over implicit one from module path collection = instantiate() for task in tasks: collection.add_task(task) if config: collection.configure(config) return collection
[docs] def add_task(self, task, name=None, aliases=None, default=None): """ Add `.Task` ``task`` to this collection. :param task: The `.Task` object to add to this collection. :param name: Optional string name to bind to (overrides the task's own self-defined ``name`` attribute and/or any Python identifier (i.e. ``.func_name``.) :param aliases: Optional iterable of additional names to bind the task as, on top of the primary name. These will be used in addition to any aliases the task itself declares internally. :param default: Whether this task should be the collection default. .. versionadded:: 1.0 """ if name is None: if name = elif hasattr(task.body, "func_name"): name = task.body.func_name elif hasattr(task.body, "__name__"): name = task.__name__ else: raise ValueError("Could not obtain a name for this task!") name = self.transform(name) if name in self.collections: err = "Name conflict: this collection has a sub-collection named {!r} already" # noqa raise ValueError(err.format(name)) self.tasks[name] = task for alias in list(task.aliases) + list(aliases or []): self.tasks.alias(self.transform(alias), to=name) if default is True or (default is None and task.is_default): if self.default: msg = "'{}' cannot be the default because '{}' already is!" raise ValueError(msg.format(name, self.default)) self.default = name
[docs] def add_collection(self, coll, name=None): """ Add `.Collection` ``coll`` as a sub-collection of this one. :param coll: The `.Collection` to add. :param str name: The name to attach the collection as. Defaults to the collection's own internal name. .. versionadded:: 1.0 """ # Handle module-as-collection if isinstance(coll, types.ModuleType): coll = Collection.from_module(coll) # Ensure we have a name, or die trying name = name or if not name: raise ValueError("Non-root collections must have a name!") name = self.transform(name) # Test for conflict if name in self.tasks: err = ( "Name conflict: this collection has a task named {!r} already" ) # noqa raise ValueError(err.format(name)) # Insert self.collections[name] = coll
def _split_path(self, path): """ Obtain first collection + remainder, of a task path. E.g. for ``"subcollection.taskname"``, return ``("subcollection", "taskname")``; for ``"subcollection.nested.taskname"`` return ``("subcollection", "nested.taskname")``, etc. An empty path becomes simply ``('', '')``. """ parts = path.split(".") coll = parts.pop(0) rest = ".".join(parts) return coll, rest
[docs] def subcollection_from_path(self, path): """ Given a ``path`` to a subcollection, return that subcollection. .. versionadded:: 1.0 """ parts = path.split(".") collection = self while parts: collection = collection.collections[parts.pop(0)] return collection
def __getitem__(self, name=None): """ Returns task named ``name``. Honors aliases and subcollections. If this collection has a default task, it is returned when ``name`` is empty or ``None``. If empty input is given and no task has been selected as the default, ValueError will be raised. Tasks within subcollections should be given in dotted form, e.g. ''. Subcollection default tasks will be returned on the subcollection's name. .. versionadded:: 1.0 """ return self.task_with_config(name)[0] def _task_with_merged_config(self, coll, rest, ours): task, config = self.collections[coll].task_with_config(rest) return task, dict(config, **ours)
[docs] def task_with_config(self, name): """ Return task named ``name`` plus its configuration dict. E.g. in a deeply nested tree, this method returns the `.Task`, and a configuration dict created by merging that of this `.Collection` and any nested `Collections <.Collection>`, up through the one actually holding the `.Task`. See `~.Collection.__getitem__` for semantics of the ``name`` argument. :returns: Two-tuple of (`.Task`, `dict`). .. versionadded:: 1.0 """ # Our top level configuration ours = self.configuration() # Default task for this collection itself if not name: if self.default: return self[self.default], ours else: raise ValueError("This collection has no default task.") # Normalize name to the format we're expecting name = self.transform(name) # Non-default tasks within subcollections -> recurse (sorta) if "." in name: coll, rest = self._split_path(name) return self._task_with_merged_config(coll, rest, ours) # Default task for subcollections (via empty-name lookup) if name in self.collections: return self._task_with_merged_config(name, "", ours) # Regular task lookup return self.tasks[name], ours
def __contains__(self, name): try: self[name] return True except KeyError: return False
[docs] def to_contexts(self): """ Returns all contained tasks and subtasks as a list of parser contexts. .. versionadded:: 1.0 """ result = [] for primary, aliases in six.iteritems(self.task_names): task = self[primary] result.append( ParserContext( name=primary, aliases=aliases, args=task.get_arguments() ) ) return result
[docs] def subtask_name(self, collection_name, task_name): return ".".join( [self.transform(collection_name), self.transform(task_name)] )
[docs] def transform(self, name): """ Transform ``name`` with the configured auto-dashes behavior. If the collection's ``auto_dash_names`` attribute is ``True`` (default), all non leading/trailing underscores are turned into dashes. (Leading/trailing underscores tend to get stripped elsewhere in the stack.) If it is ``False``, the inverse is applied - all dashes are turned into underscores. .. versionadded:: 1.0 """ # Short-circuit on anything non-applicable, e.g. empty strings, bools, # None, etc. if not name: return name from_, to = "_", "-" if not self.auto_dash_names: from_, to = "-", "_" replaced = [] end = len(name) - 1 for i, char in enumerate(name): # Don't replace leading or trailing underscores (+ taking dotted # names into account) # TODO: not 100% convinced of this / it may be exposing a # discrepancy between this level & higher levels which tend to # strip out leading/trailing underscores entirely. if ( i not in (0, end) and char == from_ and name[i - 1] != "." and name[i + 1] != "." ): char = to replaced.append(char) return "".join(replaced)
def _transform_lexicon(self, old): """ Take a Lexicon and apply `.transform` to its keys and aliases. :returns: A new Lexicon. """ new_ = Lexicon() # Lexicons exhibit only their real keys in most places, so this will # only grab those, not aliases. for key, value in six.iteritems(old): # Deepcopy the value so we're not just copying a reference new_[self.transform(key)] = copy.deepcopy(value) # Also copy all aliases, which are string-to-string key mappings for key, value in six.iteritems(old.aliases): new_.alias(from_=self.transform(key), to=self.transform(value)) return new_ @property def task_names(self): """ Return all task identifiers for this collection as a one-level dict. Specifically, a dict with the primary/"real" task names as the key, and any aliases as a list value. It basically collapses the namespace tree into a single easily-scannable collection of invocation strings, and is thus suitable for things like flat-style task listings or transformation into parser contexts. .. versionadded:: 1.0 """ ret = {} # Our own tasks get no prefix, just go in as-is: {name: [aliases]} for name, task in six.iteritems(self.tasks): ret[name] = list(map(self.transform, task.aliases)) # Subcollection tasks get both name + aliases prefixed for coll_name, coll in six.iteritems(self.collections): for task_name, aliases in six.iteritems(coll.task_names): # Cast to list to handle Py3 map() 'map' return value, # so we can add to it down below if necessary. aliases = list( map(lambda x: self.subtask_name(coll_name, x), aliases) ) # Tack on collection name to alias list if this task is the # collection's default. if coll.default == task_name: aliases += (coll_name,) ret[self.subtask_name(coll_name, task_name)] = aliases return ret
[docs] def configuration(self, taskpath=None): """ Obtain merged configuration values from collection & children. :param taskpath: (Optional) Task name/path, identical to that used for `~.Collection.__getitem__` (e.g. may be dotted for nested tasks, etc.) Used to decide which path to follow in the collection tree when merging config values. :returns: A `dict` containing configuration values. .. versionadded:: 1.0 """ if taskpath is None: return copy_dict(self._configuration) return self.task_with_config(taskpath)[1]
[docs] def configure(self, options): """ (Recursively) merge ``options`` into the current `.configuration`. Options configured this way will be available to all tasks. It is recommended to use unique keys to avoid potential clashes with other config options For example, if you were configuring a Sphinx docs build target directory, it's better to use a key like ``''`` than simply ``'target'``. :param options: An object implementing the dictionary protocol. :returns: ``None``. .. versionadded:: 1.0 """ merge_dicts(self._configuration, options)
[docs] def serialized(self): """ Return an appropriate-for-serialization version of this object. See the documentation for `.Program` and its ``json`` task listing format; this method is the driver for that functionality. .. versionadded:: 1.0 """ return { "name":, "help": helpline(self), "default": self.default, "tasks": [ { "name": self.transform(, "help": helpline(x), "aliases": [self.transform(y) for y in x.aliases], } for x in sorted(self.tasks.values(), key=lambda x: ], "collections": [ x.serialized() for x in sorted( self.collections.values(), key=lambda x: or "" ) ], }