Metadata-Version: 1.1
Name: pyitect
Version: 0.9.0
Summary: A Simple system for structuring a modeler project architecture via plugin like modules, uses the new importlib abilities first avalible in python 3.4, includes an exec load mode for support of pyhton 3.0+
Home-page: https://github.com/Ryex/pyitect
Author: Ryexander
Author-email: Ryexander@gmail.com
License: ISC
Description: =======
        Pyitect
        =======
        
        
        A `architect <https://github.com/c9/architect>`_ inspired plugin
        framework for Python 3
        
        .. contents:: Table of Contents
           :depth: 2
        
        *****************
        What is a Plugin?
        *****************
        
        
        a plugin to pyitect is simply a folder with a .json file of the same
        name inside
        
        ::
        
            /Im-A-Plugin
                Im-A-Plugin.json
                file.py
        
        A plugin has a name, a version, an author, a .py file, and it provides
        Components used to build your application. components are simply names
        in the module's namespace after the file is imported
        
        a plugin's json file provides information about the plugin as well as
        lists components it provides and components it needs on load
        
        here's an example, all fields are mandatory but the consumes and
        provides CAN be left as empty containers, but then the plugin would be
        useless would it not? not providing components and all?
        
        ::
        
            {
                "name": "Im-A-Plugin",
                "author": "Ryex",
                "version": "0.0.1",
                "file": "file.py",
                "mode": "import", // optional either 'import' or 'exec'
                "on_enable": "dostuff.py", // optional, runs this file when the plugin is enabled
                "consumes": {
                    "foo" : ""
                },
                "provides": {
                    "Bar": ""
                }
            }
        
        -  **name** -> the name of the plugin (No spaces)
        -  **author** -> the author of the plugin
        -  **version** -> a version for the plugin, a string that can be any form set up tools supports
        -  **file** -> a path to the file that when imported will provide a module who's namespace contains all provided plugins
        -  **mode** -> (OPTIONAL) defaults to `import` on python 3.4 and up `ecec` otherwise: sets the import mode
        -  **consumes** -> a mapping of needed component names to version strings, empty string = no requirement
        -  **provides** -> a mapping of provided component names to prefix mappings 
        
        ********************
        Version Requierments
        ********************
        
        a plugin can provide version requirements for the components it's
        importing
        
        a version string is formatted like so
        
        ::
        
            plugin_name:version_requirements
        
        both parts are optional and an empty string or a string containing only
        an '\*' means no requirement a version requirement can include logical
        operators to get version greater than or less than the specified value,
        you can evem select ranges
        
        here are some examples
        
        ::
        
            ""  // no requirement
            "*" // no requierment
            "FooPlugin" // from this plugin and no other, but any version
            "FooPlugin:*" // from this plugin and no other, but any version
            "FooPlugin:1" // from this plugin and no other, version 1.x.x
            "FooPlugin:1.0" // 1.0.x
            "FooPlugin:1.0.1" // version 1.0.1 or any post release
            "FooPlugin:1.0.1-pre123" // 1.0.1-pre123 -> this exact version
            "FooPlugin:1.0.1.1" // oh did I mention that your version strings can basically go on forever? choose your own style!
            "FooPlugin:1.2" // 1.2.x and any pre/post/dev release
            "FooPlugin:>1.0" // greater than 1.0
            "FooPlugin:>=1.2.3" // greater than or equal to 1.2.3
            "FooPlugin:<=2.1.4" // less than or equal to 2.1.4
            "FooPlugin:>1.0 <2.3" // greater than 1.0 and less than 2.3
            "FooPlugin:1.0.5 - 2.4.5" // between 1.0.5 and 2.3.x inclusive
            "FooPlugin:1.0 || 2.5.1" // either 1.0.x or 2.5.1
            "FooPlugin:1.0 || 2.3.3 - 3.1.0 || >=4.3 <5.2.6-pre25" // get real complicated, cause you know, you might need it.
        
        pyitect uses `parse_version` from the `pkg_resources` module (part
        of setuptools) to turn version strings into tuples that are then
        compared lexagraphicaly so any version string system that works with
        setuptools works here
        
        learn more from the `parse\_version docs <https://pythonhosted.org/setuptools/pkg_resources.html#id33>`_
        
        ******************************************
        Letting plugins access consumed Components
        ******************************************
        
        
        inside your plugin files you need to get access to your consumed
        components right? here's how you do it
        
        ::
        
            #file.py
            from PyitectConsumes import foo
        
            class Bar(object):
                def __init__():
                    foo("it's a good day to be a plugin")
        
        **************************
        Setting up a Plugin system
        **************************
        
        
        Here's how you set up a plugin system
        
        ::
        
            from pyitect import System
            #in case you need to specify versions for plugins that don't have a default
            #or you need to be sure a specific version is used,
            #you can supply a mapping of component names to version strings on system setup
            system = System({foo: "*"})
        
            system.search("path/to/your/plugins/tree")
            #enable the plugins found, you can of course do some filtering first
            plugins = [system.plugins[n][v] for n in system.plugins for v in system.plugins[n]]
            system.enable_plugins(plugins)
        
            Bar = system.load("Bar")
        
        The general idea is to create a system, search some path or paths for plugins and then enable them
        you can of course filter `System.plugins` in some way before passing it to `System.enable_plugins`
        
        Enable Plugins
        ==============
        
        
        `System.enable_plugins()` accepts either a single `Plugin` object, a mapping object 
        where each key maps to a `Plugin` object, or an iterable (ie a list) of `Plugin` objects
        
        Plugin components are not made available to the system until they are enabled.
        
        'on_enable' Property
        ---------------------
        
        plugins can specify an `on_enable` property in this configuration. This file is exacuted 
        right after a plugin is enabled and it's components have been mapped. 
        this allows for special cases where enabling a plugin requires more than just makeing it's components avalible to be imported.
        for example is there is some system set up to be done.
            
        
        Loading Plugins
        ===============
        
        Plugins are loaded on demand when a component is loaded via
        
        ::
        
            System.load("<component name>")
            
        a plugin can also be explicitly loaded via
        
        ::
        
            System.load_plugin(plugin, version)
            
        where `plugin` is the plugin name and `version` is the version
        
        Plugin Loading Modes
        --------------------
        
        Plugins can be loaded in two different modes `import` and
        `exec`. Both modes can be set in the plugin's json file just like
        any other optional
        
        import mode
        ^^^^^^^^^^^
        
        
        `import` mode requires, and is the default on, Python version 3.4 or
        higher. It uses the newly improved import lib to load the file pointed
        to in the plugin json with the `file` property. This lets the file
        to be loaded be any file python itself could import, be it a compiled
        python module in `.pyd` or `.so` form, a `.pyc` or `.pyo`
        compiled source file, or just a plain old `.py` source file.
        
        exec mode
        ^^^^^^^^^
        
        
        loads plugins by compiling the provided source file into a code object
        and executing the code object inside a blank Module object. This
        effectively recreates an import process by it's limited in that it can
        only load raw python source not compiled `.pyc` or `.pyo` \_\_init
        ### both in both cases relative imports DO NOT WORK. the plugin folder
        is temporarily added to the search path so absolute imports work but
        relatives will not.
        
        UNLESS the name of the file is `__init__.py` . In this special case
        the plugin folder is reconsidered as a python package and relative
        imports work as normal. exec mode does it's best to recognize this case
        by testing for the file name `__init__.py` and then setting **name**
        and **package** of the executed module to the folder name and
        temporarily injecting the module into sys.modules.
        
        Pyitect does it's best to isolate plugins from the rest of the program
        by keeping clean namespaces but this is no substitute for good security
        only load know plugins.
        
        
        get_plugin_module
        ------------------
        
        Loaded pluginss do NOT store their module object in `sys.modules` 
        instead they are stored internally at `System.loaded_plugins` (a mapping of plugin names and version strings to module objects)
        Normaly you would only access a plugin's components but the module obejct can be accessed explicitly with
        
        ::
        
            System.get_plugin_module(plugin [, version=version_stirng])
            
        if no version is given it fetches the highest version avalible.
        
        a plugin must allready be loaded (not just enabled) to fetch it's module obejct
        
        Loading multiple versions of one component
        ==========================================
        
        
        There are times when you might want to load more than one version of a
        plugin at once. why? well lets say you have a `tool` component that
        does some function on a piece of data, what function? not important but
        if you say wanted to extend the system to also allow an number of other
        functions on that same data, perhaps some function provided by a 3d
        party. how do make it so that all available functions are loaded?
        
        Pyitect lets you classify all these as a single components with
        different versions and then load them all.
        
        ::
        
            System.load(component, requirements={'component': 'plugin:version'})
        
        in this case the requirements for the component can be set to load a
        spesfic versi
        --------------------------on from one plugin, bypassing the default from the system.
        
        Tracking loaded Components
        ==========================
        
        Pyitect tracks used components at anytime `System.useing` can be
        inspected to find all components that have been requested and from what
        plugins they have been loaded along with versions `System.useing` is
        laying out as a multilayer dictionary with arrays of loaded versions,
        here is an example where more than one version of a component is active
        
        ::
        
            >> System.useing
            {
                'component1' : {
                    'plugin1`: ['1.0.2']
                },
                'special_component1' : {
                    'special_plugin1': ['0.1.3'],
                    'special_plugin2': ['0.2.4', '1.0.1-pre3']
                }
            }
        
        
        Providing multiple versions of a component from the same plugin
        ===============================================================
        
        
        what if you want to provide multiple versions of a component from the
        same plugin? if you have a system like in the Loading multiple versions
        of one component section above then you may want to provide multiple
        versions from one plugin
        
        this can be accomplished by providing a version post-fix for the
        provided component and map it to the Global name it can be accessed from
        in the loaded module
        
        you may of noticed that provided components are mapped to a string
        
        ::
        
            {
                "name": "Im-A-Plugin",
                ...
                "provides": {
                    "Bar": ""
                }
            }
        
        that string is a post-fix mapping, an empty string represent no mapping
        (the component is provided in the loaded module under the same name, no
        version post-fix)
        
        if however we did this
        
        ::
        
            {
                "name": "Im-A-Plugin",
                ...
                "version": "0.0.1",
                ...
                "provides": {
                    "Bar": "bar_type_1=bar1"
                }
            }
        
        then a special version would be added to the system, version
        `0.0.1-bar_type_1`, and when you required that version when loading
        the `Bar` component it would load the name `bar1` from the module
        loaded from the `Im-A-Plugin` plugin. More than one mapping can be
        provided by separating them with the pipe `|` character in this way
        more than one version can be provided. example:
        
        ::
        
            {
                "name": "Im-A-Plugin",
                ...
                "version": "0.0.1",
                ...
                "provides": {
                    "Bar": "bar_type_1=bar1 | bar_type_2=bar2 | bar_type_3=bar3 | bar_type_4=bar4 | bar_type_5=bar5"
                }
            }
        
        creating versions mappings
        --------------------------
        
        ::
        
            0.0.1-bar_type_1 -> bar1
            0.0.1-bar_type_2 -> bar2
            0.0.1-bar_type_3 -> bar3
            0.0.1-bar_type_4 -> bar4
            0.0.1-bar_type_5 -> bar5
        
        it is also possible to use the mapping to simple provide an alternate
        name to acces the component under
        
        ::
        
            {
                "name": "Im-A-Plugin",
                ...
                "version": "0.0.1",
                ...
                "provides": {
                    "FooBar": "=foobar",
                    "BARFOO": "barfootype=barfoo"
                }
            }
        
        notice that the version post-fix can be left out, as long as the `=`
        is there the capitalized name `FooBar` can be accessed via the
        lowercase name `foobar` but will still have the normal `0.0.1`
        version
        
        the second one `BARFOO` wil create a `0.0.1-barfootype` version.
        
        ******
        Events
        ******
        
        The plugin system also includes a simple event system bount to the
        `System` object, it simply allows one to register a function to an
        event name and when `System.fire_event` is called it calls all
        registered functions passing the extra args and kwargs to them
        
        pyitect fires some event internally so that you can keep track of when
        the system finds and loads plugins
        
        Using Events
        ============
        
        Pyitect supplies three methods for dealing with events
        
        System.bind_event
        -----------------
        ::
        
            System.bind_event('name', Function)
        
        binds `Function` to the event `'name'`. when an event of `'name'` is fired 
        the function will be called wall all extra parameters passed to the `fire_event` call.
        
        System.unbind_event
        -------------------
        ::
        
            System.unbind_event('name', Function)
        
        removes `Function` form the list of functions to be called when the event is fired
        
        System.fire_event
        -----------------
        ::
        
            System.fire_event('name', *args, **kwargs)
        
        fires the event `'name'`, calling all bound functions with `*args` and `**kwargs`
        
        Events Fired Internaly
        ======================
        
        
        plugin\_found
        -------------
        
        
        
        a function bound to this event gets called every time a plugin is found
        during a search called an example is provided:
        
        ::
        
            def onPluginFound (path, plugin):
                """
                path : the full path to the folder containing the plugin
                plugin : plugin version string (ie 'plugin_name:version')
                """
                print("plugin `%s` found at `%s`" % (plugin, path))
        
        plugin\_loaded
        --------------
        
        
        
        a function bound to this event is called every time a new plugin is
        loaded during a component load example:
        
        ::
        
            def onPluginLoad (plugin, plugin_required, component_needed):
                """
                plugin : plugin version string (ie 'plugin_name:version')
                plugin_required: version string of the plugin that required the loaded plugin (version string ie 'plugin_name:version') (might be None)
                component_needed: the name of the component needed by the requesting plugin
                """
                print("plugin `%s` was loaded by plugin `%s` during a request for the `%s` component" % (plugin, plugin_required, component_needed))
        
        component\_loaded
        -----------------
        
        a function bound to this event is called every time a component is
        sucessfuly loaded example:
        
        ::
        
            def onComponentLoad (component, plugin_required, plugin_loaded):
                """
                component : the name of the component loaded
                plugin_required : version string of the plugin that required the loaded component (version string ie 'plugin_name:version') (might be None)
                plugin_loaded : version string of the plugin that the component was loaded from (version string ie 'plugin_name:version')
                """
                print("Component `%s` loaded, required by `%s`, loaded from `%s`" % (component, plugin_required, plugin_loaded) )
        
        
        ****************************************
        Iterating over available plugin versions
        ****************************************
        
        
        Pyitect provides an iterator function to iterate over available
        providers for a component `System.ittrPluginsByComponent`
        
        this function will loop over all plugin that provided the component and
        return a tulple of the plugin name and it's highest available version.
        if there are post-fix mappings for the component on that plugin it will
        list them too.
        
        ::
        
            for plugin, version in System.ittrPluginsByComponent('component_name'):
                print("Plugin %s provides The component at version %s" % (plugin, version))
        
        ********
        Examples
        ********
        
        
        For more information checkout the tests directory, it should be a fairly
        straight forward explanation form there.
        
        *******
        LICENSE
        *******
        
        
        Copyright (c) 2014, Benjamin "Ryex" Powers ryexander@gmail.com
        
        Permission to use, copy, modify, and/or distribute this software for any
        purpose with or without fee is hereby granted, provided that the above
        copyright notice and this permission notice appear in all copies.
        
        THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
        WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
        MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
        ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
        WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
        ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
        OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
Keywords: architect project modeler plugin
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: License :: OSI Approved :: ISC License (ISCL)
Classifier: Intended Audience :: Developers
Classifier: Intended Audience :: Information Technology
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Topic :: Software Development
Classifier: Topic :: Software Development :: Libraries
Classifier: Topic :: Software Development :: Libraries :: Application Frameworks
