bokeh.application.application¶

Provide the Application class.

Application instances are factories for creating new Bokeh Documents.

When a Bokeh server session is initiated, the Bokeh server asks the Application for a new Document to service the session. To do this, the Application first creates a new empty Document, then it passes this new Document to the modify_document method of each of its handlers. When all handlers have updated the Document, it is used to service the user session.

class Application(*handlers, **kwargs)[source]¶

An Application is a factory for Document instances.

__init__(*handlers, **kwargs)[source]¶

Application factory.

Parameters: handlers (seq[Handler]) – List of handlers to call. The URL is taken from the first one only.

Keyword Arguments:

Parameters:	handlers (seq[Handler]) – List of handlers to call. The URL is taken from the first one only.
Keyword Arguments:
	metadata (dict) – abitrary user-supplied JSON data to make available with the application. The server will provide a URL `http://applicationurl/metadata` which returns a JSON blob of the form: { "data": { "hi": "hi", "there": "there" }, "url": "/myapp" } The user-supplied metadata is returned as-is under the `"data"` key in the blob.

metadata (dict) –

abitrary user-supplied JSON data to make available with the application.

The server will provide a URL http://applicationurl/metadata which returns a JSON blob of the form:

{
    "data": {
        "hi": "hi",
        "there": "there"
    },
    "url": "/myapp"
}

The user-supplied metadata is returned as-is under the "data" key in the blob.

add(handler)[source]¶

Add a handler to the pipeline used to initialize new documents.

Parameters:	handler (Handler) – a handler for this Application to use to process Documents

create_document()[source]¶: Creates and initializes a document using the Application’s handlers.

initialize_document(doc)[source]¶: Fills in a new document using the Application’s handlers.

on_server_loaded(server_context)[source]¶

Invoked to execute code when a new session is created.

This method calls on_server_loaded on each handler, in order, with the server context passed as the only argument.

on_server_unloaded(server_context)[source]¶

Invoked to execute code when the server cleanly exits. (Before stopping the server’s IOLoop.)

This method calls on_server_unloaded on each handler, in order, with the server context passed as the only argument.

Warning

In practice this code may not run, since servers are often killed by a signal.

on_session_created(session_context)[source]¶

Invoked to execute code when a new session is created.

This method calls on_session_created on each handler, in order, with the session context passed as the only argument.

May return a Future which will delay session creation until the Future completes.

on_session_destroyed(session_context)[source]¶

Invoked to execute code when a session is destroyed.

This method calls on_session_destroyed on each handler, in order, with the session context passed as the only argument.

Afterwards, session_context.destroyed will be True.

handlers¶: The ordered list of handlers this Application is configured with.

metadata¶: Arbitrary user-supplied metadata to associate with this application.

safe_to_fork¶

static_path¶: Path to any (optional) static resources specified by handlers.

class ServerContext[source]¶

A harness for server-specific information and tasks related to collections of Bokeh sessions.

This base class is probably not of interest to general users.

add_next_tick_callback(callback)[source]¶

Add a callback to be run on the next tick of the event loop.

Subclasses must implement this method.

Parameters:

Parameters:	callback (callable) – a callback to add The callback will execute on the next tick of the event loop, and should have the form `def callback()` (i.e. it should not accept any arguments)
Returns:	an ID that can be used with `remove_next_tick_callback`.

callback (callable) –

a callback to add

The callback will execute on the next tick of the event loop, and should have the form def callback() (i.e. it should not accept any arguments)

Returns: an ID that can be used with remove_next_tick_callback.

add_periodic_callback(callback, period_milliseconds)[source]¶

Add a callback to be run periodically until it is removed.

Subclasses must implement this method.

Parameters:	callback (callable) – a callback to add The callback will execute periodically on the event loop as specified, and should have the form `def callback()` (i.e. it should not accept any arguments) period_milliseconds (int) – number of milliseconds to wait between executing the callback.
Returns:	an ID that can be used with `remove_periodic_callback`.

add_timeout_callback(callback, timeout_milliseconds)[source]¶

Add a callback to be run once after timeout_milliseconds.

Subclasses must implement this method.

Parameters:	callback (callable) – a callback to add The callback will execute once on the event loop after the timeout has passed, and should have the form `def callback()` (i.e. it should not accept any arguments) timeout_milliseconds (int) – number of milliseconds to wait before executing the callback.
Returns:	an ID that can be used with `remove_timeout_callback`.

remove_next_tick_callback(callback_id)[source]¶

Remove a callback added with add_next_tick_callback, before it runs.

Subclasses must implement this method.

Parameters:	callback_id – the ID returned from `add_next_tick_callback`

remove_periodic_callback(callback_id)[source]¶

Removes a callback added with add_periodic_callback.

Subclasses must implement this method.

Parameters:	callback_id – the ID returned from `add_periodic_callback`

remove_timeout_callback(callback_id)[source]¶

Remove a callback added with add_timeout_callback, before it runs.

Subclasses must implement this method.

Parameters:	callback_id – the ID returned from `add_timeout_callback`

sessions¶

SessionContext instances belonging to this application.

Subclasses must implement this method.

class SessionContext(server_context, session_id)[source]¶

A harness for server-specific information and tasks related to Bokeh sessions.

This base class is probably not of interest to general users.

__init__(server_context, session_id)[source]¶

with_locked_document(func)[source]¶

Runs a function with the document lock held, passing the document to the function.

Subclasses must implement this method.

Parameters:	func (callable) – function that takes a single parameter (the Document) and returns `None` or a `Future`
Returns:	a `Future` containing the result of the function

destroyed¶

If True, the session has been discarded and cannot be used.

A new session with the same ID could be created later but this instance will not come back to life.

id¶: The unique ID for the session associated with this context.

server_context¶: The server context for this session context