D 2015-05-11T21:17:18.996
L write\sa\splugin
N text/x-markdown
P 2f2c2016a6824a8870ec3420d9d942fb687f8412
U mario
W 5928
Writing a new plugin is often trivial.
Just create a new `channels/name.py` following this structure:

    # title: MyPlugin
    # description: my radio list
    # url: http://www.mymusicstation.com/
    # version: 0.1
    # type: channel
    # category: radio
    # priority: optional
    # config: -

    from config import *
    from channels import *
    import ahttp

    class myplugin (ChannelPlugin):
        has_search = False
        titles = dict(listeners=False)
        categories = []
        catmap = {}
        listformat = "pls"

        def update_categories(self):
            self.categories = ["Pop", "Rock", "etc"]

        def update_streams(self, cat, search=None):
            entries = []
            # ...
            # get it from somewhere
            # ...        
            return entries

### Plugin meta block

The description block on top is used for the [plugin management](wiki/plugin+meta+data) (and documentative purposes). This is meant to cleanly separate in-application values (like .module or .has_search, .catmap) from attributes that just serve initialization.

All fields show up in `self.meta`, for instance the `meta["title"]` or `meta["url"]` are occasionally used. The `config[]` entry is a list/dict combination, and its defaults automatically thrown into `conf.*` variables. Therefore plugins can use their settings right away (e.g. `conf.myplugin_bitrate=128`)

### update_categories()

Each plugin needs a `update_categories()` method. This can be a stub, if the channel plugin has a static list of genres. If so, just set the `categories = [...]` declaration right away. The method is only used if the default categories list is empty, needs to be renewed from the service (e.g. whenever the menu entry Channel>Update_categories is used). There's also a `catmap={}` dict in case category/genre titles have to be associated with service ids.

### update_streams()

More importantly you need the `update_streams()` method to fetch station lists. It receives a `cat` parameter, for instance `"Pop"`. Then do whatever API query or website scraping (regex/pyquery) is necessary to populate a list.

Most plugins will return a list of dicts like:

    [
      {title: Radio123, url: http://pls, genre: Pop, playing: Song123},
      {title: Next.Radio, url: http://pls, genre: Pop, playing: Next Song},
      ...
    ]

The title is required, and the streaming URL of course. Other fields are mostly optional.

   * Standard fields are:

      * <kbd>genre</kbd> - the category name
      * <kbd>title</kbd> - station title
      * <kbd>url</kbd> - streaming url (to pls or m3u resource)
      * <kbd>playing</kbd> - currently playing song, if any
      * <kbd>homepage</kbd> - station homepage
      * <kbd>bitrate</kbd> - (int) audio bitrate (like 128)
      * <kbd>listeners</kbd> - (int) number of listeners
      * <kbd>format</kbd> - to set a custom audio format (audio/ogg)

   * Internal fields are: 

      * <kbd>favicon</kbd> - path to localized favicon, either from <kbd>homepage</kbd> or <kbd>img</kbd> url
      * <kbd>state</kbd> - a gtk icon
      * <kbd>deleted</kbd> - strikethrough for deleted entries
      * <kbd>favourite</kbd> - add a star for bookmarked stations
      * <kbd>search_col</kbd> - search color
      * <kbd>search_set</kbd> - search state

   * With a `datamap=[]` declaration custom field names could be displayed.

   * Often you just want to rename the column titles however - per `title=dict(listeners="Whatever")` in the class declaration.

You can add any additional fields of your choosing.

### streams = {}

Received station lists get stored internally in a `streams={"Pop":[...]}` dict, and cached in the `~/.config/streamtuner2/cache/` directory of course.

### conf. options

You can access your <kbd>config:</kbd> options per the global `conf.*` dict. Take care to prefer unambigious names like `conf.myplugin_pagesize` etc.

### Attributes

There are a couple of other attributes.

 - **has_search** `= False`  
   This flag documents if live server searches are available. If it's supported, then the `update_streams()` method may be called with `cat=None` and `search="Find me maybe"` instead; and it's then responsible to do some searching.

 - **audioformat** `= "audio/mpeg"`  
   Sets the default audio stream type for this channel. (Note that each individual stream entry may carry its own `format` attribute, just in case.)

 - **listformat** `= "pls"`  
   Declares the channel service playlist type. Can be either "pls" or "m3u" or "xspf" if the server is super modern. Most directories provide `http://myradiolist.com/listen-12345.pls` URLs, so should use `"pls"` here.  It's also possible to use "href" here, if you can't be sure of audio or playlist format types. And "srv" if the provider has a clean list of direct MP3/Ogg streaming URLs only.

 - **titles =** `dict(listeners=False)`  
   This defines which station column titles to show. There are title=, genre= which you commonly have. And there is playing= or bitrate= and homepage= which you can omit by setting it to `=False`. Alternatively just rename them with `playing="Artist/Album name`.

 - **datamap** = `[...]`  
   If you want some complexity, such as elaborate column title renaming, extra pixmaps/favicons, or using custom row fields/attributes - then this can all be accomplished with a Gtk TreeView *datamap*. No, you don't want to do that.

 - Other internal fields are listed in `channels/__init__.py`

### Installation

To have a new plugin picked up, you need to copy/symlink the file into `/usr/share/streamtuner2/channels/`. It's imported from the `channels` module group automatically. Which allows relocatability, and later even local plugins. (Which is commonly unneeded featuritis though. So not yet implemented.)

Z 1cc23fe4cff06815077f35b9af7b7824