4. Modules

4.1. Module

class tornado_websockets.modules.Module(name='')

4.2. Progress bar

The module « ProgressBar » facilitate the communication between the server-side and client-side of a progression bar.

Server-side:

• An easier communication with client-side ProgressBar module
• Handle init, update and done events,
• Update current progression value with tick() or reset()

Client-side:

• An easier communication with server-side ProgressBar module,
• Handle init, update and done events,
• Rendering a progression bar by using HTML5 or Bootstrap rendering.

4.2.1. Server-side

4.2.1.1. Construction

class tornado_websockets.modules.ProgressBar(name='', min=0, max=100, indeterminate=False)

Initialize a new ProgressBar module instance.

If min and max values are equal, this progress bar has its indeterminate state set to True.

Parameters:

• min (int) – Minimum value
• max (int) – Maximum value

4.2.1.2. Methods

ProgressBar.reset()

Reset progress bar’s progression to its minimum value.

ProgressBar.tick(label=None)

Increments progress bar’s _current by 1 and emit update event. Can also emit done event if progression is done.

Call emit_update() method each time this method is called. Call emit_done() method if progression is done.

Parameters:label (str) – A label which can be displayed on the client screen

ProgressBar.is_done()

Return True if progress bar’s progression is done, otherwise False.

Returns False if progress bar is indeterminate, returns True if progress bar is determinate and current value is equals to max value. Returns False by default.

Return type:bool

4.2.1.3. Events

ProgressBar.on(callback)

Shortcut for tornado_websockets.websocket.WebSocket.on() decorator, but with a specific prefix for each module.

Parameters:callback (Callable) – function or a class method. Returns:callback parameter.

ProgressBar.emit_init()

Emit before_init, init and after_init events to initialize a client-side progress bar.

If progress bar is not indeterminate, min, max and value values are sent with init event.

ProgressBar.emit_update(label=None)

Emit before_update, update and after_update events to update a client-side progress bar.

Parameters:label (str) – A label which can be displayed on the client screen

ProgressBar.emit_done()

Emit done event when progress bar’s progression is_done().

4.2.1.4. Example

from tornado import gen

from tornado_websockets.modules import ProgressBar
from tornado_websockets.websocket import WebSocket

ws = WebSocket('module_progressbar')
progressbar = ProgressBar('foo', min=0, max=100)

ws.bind(progressbar)


@progressbar.on
def reset():
    progressbar.reset()


@progressbar.on
@gen.engine  # Make this function asynchronous for Tornado's IOLoop
def start():
    for value in range(0, progressbar.max):
        yield gen.sleep(.1)  # like time.sleep(), but asynchronous with @gen.engine
        progressbar.tick(label="[%d/%d] Tâche %d terminée" % (progressbar.current + 1, progressbar.max, value))

4.2.2. Client-side

Read documentation about ProgressBar client-side module here.