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Top-level package for Fast Dash.

FastDash

Fast Dash app object containing automatically generated UI components and callbacks.

This is the primary Fast Dash data structure. Can be thought of as a wrapper around a flask WSGI application. It has in-built support for automated UI generation and sets all parameters required for Fast Dash app deployment.

Source code in fast_dash/fast_dash.py
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class FastDash:
    """
    Fast Dash app object containing automatically generated UI components and callbacks.

    This is the primary Fast Dash data structure. Can be thought of as a wrapper around
    a flask WSGI application. It has in-built support for automated UI generation and
    sets all parameters required for Fast Dash app deployment.
    """

    def __init__(
        self,
        callback_fn,
        inputs=None,
        outputs=None,
        title=None,
        title_image_path=None,
        subheader=None,
        github_url=None,
        linkedin_url=None,
        twitter_url=None,
        navbar=True,
        footer=True,
        theme="JOURNAL",
        update_live=False,
        mode=None,
        minimal=False,
        disable_logs=False,
        **kwargs
    ):
        """
        Args:
            callback_fn (func): Python function that Fast Dash deploys.
                This function guides the behavior of and interaction between input and output components.

            inputs (Fast component, list of Fast components, optional): Components to represent inputs of the callback function.
                Defaults to None. If `None`, Fast Dash attempts to infer the best components from callback function's type
                hints and default values. In the absence of type hints, default components are all `Text`.

            outputs (Fast component, list of Fast components, optional): Components to represent outputs of the callback function.
                Defaults to None. If `None`, Fast Dash attempts to infer the best components from callback function's type hints.
                In the absence of type hints, default components are all `Text`.

            title (str, optional): Title given to the app. Defaults to None. If `None`, function name (assumed to be in snake case)
                is converted to title case.

            title_image_path (str, optional): Path (local or URL) of the app title image. Defaults to None.

            subheader (str, optional): Subheader of the app, displayed below the title image and title. Defaults to None.
                If `None`, Fast Dash tries to use the callback function's docstring instead.

            github_url (str, optional): GitHub URL for branding. Displays a GitHub logo in the navbar, which takes users to the
                specified URL. Defaults to None.

            linkedin_url (str, optional): LinkedIn URL for branding Displays a LinkedIn logo in the navbar, which takes users to the
                specified URL. Defaults to None.

            twitter_url (str, optional): Twitter URL for branding. Displays a Twitter logo in the navbar, which takes users to the
                specified URL. Defaults to None.

            navbar (bool, optional): Display navbar. Defaults to True.

            footer (bool, optional): Display footer. Defaults to True.

            theme (str, optional): Apply theme to the app. Defaults to "JOURNAL". All available themes can be found
                at https://bootswatch.com/.

            update_live (bool, optional): Enable hot reloading. Defaults to False.

            mode (str, optional): Mode in which to launch the app. Acceptable options are `None`, `jupyterlab`, `inline`, 'external`.
                Defaults to None.

            minimal (bool, optional): Display minimal version by hiding navbar, title, title image, subheader and footer.
                Defaults to False.

            disable_logs (bool, optional): Hide app logs. Sets logger level to `ERROR`. Defaults to False.
        """

        self.callback_fn = callback_fn
        self.inputs = (
            _infer_components(callback_fn, is_input=True) if inputs is None else inputs
        )
        self.outputs = (
            _infer_components(callback_fn, is_input=False)
            if outputs is None
            else outputs
        )
        self.update_live = update_live
        self.mode = mode
        self.disable_logs = disable_logs
        self.kwargs = kwargs

        if self.disable_logs is True:
            log = logging.getLogger("werkzeug")
            log.setLevel(logging.ERROR)

        else:
            log = logging.getLogger("werkzeug")
            log.setLevel(logging.DEBUG)

        if title is None:
            title = re.sub("[^0-9a-zA-Z]+", " ", callback_fn.__name__).title()

        self.title = title
        self.title_image_path = title_image_path
        self.subtext = subheader if subheader is not None else callback_fn.__doc__
        self.github_url = github_url
        self.linkedin_url = linkedin_url
        self.twitter_url = twitter_url
        self.navbar = navbar
        self.footer = footer
        self.minimal = minimal

        # Assign IDs to components
        self.inputs_with_ids = _assign_ids_to_inputs(self.inputs, self.callback_fn)
        self.outputs_with_ids = _assign_ids_to_outputs(self.outputs)
        self.ack_mask = [
            True if input_.ack is not None else False for input_ in self.inputs_with_ids
        ]

        # Default state of outputs
        self.output_state_default = [
            output_.placeholder for output_ in self.outputs_with_ids
        ]

        # Define Flask server
        server = flask.Flask(__name__)
        external_stylesheets = [
            theme_mapper(theme),
            "https://use.fontawesome.com/releases/v5.9.0/css/all.css",
        ]

        source = dash.Dash
        if self.mode is not None:
            try:
                from jupyter_dash import JupyterDash

                source = JupyterDash

            except ImportError as e:
                self.mode = None
                warnings.warn(str(e))
                warnings.warn("Ignoring mode argument")

        self.app = source(
            __name__,
            external_stylesheets=external_stylesheets,
            server=server,
            meta_tags=[
                {
                    "name": "viewport",
                    "content": "width=device-width, initial-scale=1.0, maximum-scale=1.8, minimum-scale=0.5",
                }
            ],
        )
        # Define app title
        self.app.title = self.title

        # Intialize layout
        self.set_layout()

        # Register callbacks
        self.register_callback_fn()

        # Keep track of the number of clicks
        self.submit_clicks = 0
        self.reset_clicks = 0
        self.app_initialized = False

        # Allow easier access to Dash server
        self.server = self.app.server

    def run(self, **kwargs):
        self.server.run(**kwargs) if self.mode is None else self.app.run_server(
            mode=self.mode, **kwargs
        )

    def run_server(self, **kwargs):
        self.app.run_server(**kwargs) if self.mode is None else self.app.run_server(
            mode=self.mode, **kwargs
        )

    def set_layout(self):

        if self.inputs is not None:
            input_groups = _make_input_groups(self.inputs_with_ids, self.update_live)

        if self.outputs is not None:
            output_groups = _make_output_groups(self.outputs_with_ids, self.update_live)

        default_layout = DefaultLayout(
            inputs=input_groups,
            outputs=output_groups,
            title=self.title,
            title_image_path=self.title_image_path,
            subtext=self.subtext,
            github_url=self.github_url,
            linkedin_url=self.linkedin_url,
            twitter_url=self.twitter_url,
            navbar=self.navbar,
            footer=self.footer,
            minimal=self.minimal,
        )

        self.app.layout = default_layout.layout

    def register_callback_fn(self):
        @self.app.callback(
            [
                Output(
                    component_id=output_.id,
                    component_property=output_.component_property,
                )
                for output_ in self.outputs_with_ids
            ]
            + [
                Output(
                    component_id=input_.ack.id,
                    component_property=input_.ack.component_property,
                )
                for input_ in self.inputs_with_ids
            ],
            [
                Input(
                    component_id=input_.id, component_property=input_.component_property
                )
                for input_ in self.inputs_with_ids
            ]
            + [
                Input(component_id="reset_inputs", component_property="n_clicks"),
                Input(component_id="submit_inputs", component_property="n_clicks"),
            ],
        )
        def process_input(*args):

            reset_button = args[-2]
            submit_button = args[-1]
            ack_components = [
                ack if mask is True else None
                for mask, ack in zip(self.ack_mask, list(args[:-2]))
            ]

            if submit_button > self.submit_clicks or (
                self.update_live is True and None not in args
            ):
                self.app_initialized = True
                self.submit_clicks = submit_button
                output_state = self.callback_fn(*args[:-2])

                if isinstance(output_state, tuple):
                    self.output_state = list(output_state)
                    return self.output_state + ack_components

                self.output_state = [output_state]
                return self.output_state + ack_components

            elif reset_button > self.reset_clicks:
                self.reset_clicks = reset_button
                self.output_state = self.output_state_default
                return self.output_state + ack_components

            elif self.app_initialized:
                return self.output_state + ack_components

            else:
                return self.output_state_default + ack_components

__init__(callback_fn, inputs=None, outputs=None, title=None, title_image_path=None, subheader=None, github_url=None, linkedin_url=None, twitter_url=None, navbar=True, footer=True, theme='JOURNAL', update_live=False, mode=None, minimal=False, disable_logs=False, **kwargs)

Parameters:

Name Type Description Default
callback_fn func

Python function that Fast Dash deploys. This function guides the behavior of and interaction between input and output components.

required
inputs Fast component, list of Fast components

Components to represent inputs of the callback function. Defaults to None. If None, Fast Dash attempts to infer the best components from callback function's type hints and default values. In the absence of type hints, default components are all Text.

None
outputs Fast component, list of Fast components

Components to represent outputs of the callback function. Defaults to None. If None, Fast Dash attempts to infer the best components from callback function's type hints. In the absence of type hints, default components are all Text.

None
title str

Title given to the app. Defaults to None. If None, function name (assumed to be in snake case) is converted to title case.

None
title_image_path str

Path (local or URL) of the app title image. Defaults to None.

None
subheader str

Subheader of the app, displayed below the title image and title. Defaults to None. If None, Fast Dash tries to use the callback function's docstring instead.

None
github_url str

GitHub URL for branding. Displays a GitHub logo in the navbar, which takes users to the specified URL. Defaults to None.

None
linkedin_url str

LinkedIn URL for branding Displays a LinkedIn logo in the navbar, which takes users to the specified URL. Defaults to None.

None
twitter_url str

Twitter URL for branding. Displays a Twitter logo in the navbar, which takes users to the specified URL. Defaults to None.

None
navbar bool

Display navbar. Defaults to True.

True
footer bool

Display footer. Defaults to True.

True
theme str

Apply theme to the app. Defaults to "JOURNAL". All available themes can be found at https://bootswatch.com/.

'JOURNAL'
update_live bool

Enable hot reloading. Defaults to False.

False
mode str

Mode in which to launch the app. Acceptable options are None, jupyterlab, inline, 'external`. Defaults to None.

None
minimal bool

Display minimal version by hiding navbar, title, title image, subheader and footer. Defaults to False.

False
disable_logs bool

Hide app logs. Sets logger level to ERROR. Defaults to False.

False
Source code in fast_dash/fast_dash.py
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def __init__(
    self,
    callback_fn,
    inputs=None,
    outputs=None,
    title=None,
    title_image_path=None,
    subheader=None,
    github_url=None,
    linkedin_url=None,
    twitter_url=None,
    navbar=True,
    footer=True,
    theme="JOURNAL",
    update_live=False,
    mode=None,
    minimal=False,
    disable_logs=False,
    **kwargs
):
    """
    Args:
        callback_fn (func): Python function that Fast Dash deploys.
            This function guides the behavior of and interaction between input and output components.

        inputs (Fast component, list of Fast components, optional): Components to represent inputs of the callback function.
            Defaults to None. If `None`, Fast Dash attempts to infer the best components from callback function's type
            hints and default values. In the absence of type hints, default components are all `Text`.

        outputs (Fast component, list of Fast components, optional): Components to represent outputs of the callback function.
            Defaults to None. If `None`, Fast Dash attempts to infer the best components from callback function's type hints.
            In the absence of type hints, default components are all `Text`.

        title (str, optional): Title given to the app. Defaults to None. If `None`, function name (assumed to be in snake case)
            is converted to title case.

        title_image_path (str, optional): Path (local or URL) of the app title image. Defaults to None.

        subheader (str, optional): Subheader of the app, displayed below the title image and title. Defaults to None.
            If `None`, Fast Dash tries to use the callback function's docstring instead.

        github_url (str, optional): GitHub URL for branding. Displays a GitHub logo in the navbar, which takes users to the
            specified URL. Defaults to None.

        linkedin_url (str, optional): LinkedIn URL for branding Displays a LinkedIn logo in the navbar, which takes users to the
            specified URL. Defaults to None.

        twitter_url (str, optional): Twitter URL for branding. Displays a Twitter logo in the navbar, which takes users to the
            specified URL. Defaults to None.

        navbar (bool, optional): Display navbar. Defaults to True.

        footer (bool, optional): Display footer. Defaults to True.

        theme (str, optional): Apply theme to the app. Defaults to "JOURNAL". All available themes can be found
            at https://bootswatch.com/.

        update_live (bool, optional): Enable hot reloading. Defaults to False.

        mode (str, optional): Mode in which to launch the app. Acceptable options are `None`, `jupyterlab`, `inline`, 'external`.
            Defaults to None.

        minimal (bool, optional): Display minimal version by hiding navbar, title, title image, subheader and footer.
            Defaults to False.

        disable_logs (bool, optional): Hide app logs. Sets logger level to `ERROR`. Defaults to False.
    """

    self.callback_fn = callback_fn
    self.inputs = (
        _infer_components(callback_fn, is_input=True) if inputs is None else inputs
    )
    self.outputs = (
        _infer_components(callback_fn, is_input=False)
        if outputs is None
        else outputs
    )
    self.update_live = update_live
    self.mode = mode
    self.disable_logs = disable_logs
    self.kwargs = kwargs

    if self.disable_logs is True:
        log = logging.getLogger("werkzeug")
        log.setLevel(logging.ERROR)

    else:
        log = logging.getLogger("werkzeug")
        log.setLevel(logging.DEBUG)

    if title is None:
        title = re.sub("[^0-9a-zA-Z]+", " ", callback_fn.__name__).title()

    self.title = title
    self.title_image_path = title_image_path
    self.subtext = subheader if subheader is not None else callback_fn.__doc__
    self.github_url = github_url
    self.linkedin_url = linkedin_url
    self.twitter_url = twitter_url
    self.navbar = navbar
    self.footer = footer
    self.minimal = minimal

    # Assign IDs to components
    self.inputs_with_ids = _assign_ids_to_inputs(self.inputs, self.callback_fn)
    self.outputs_with_ids = _assign_ids_to_outputs(self.outputs)
    self.ack_mask = [
        True if input_.ack is not None else False for input_ in self.inputs_with_ids
    ]

    # Default state of outputs
    self.output_state_default = [
        output_.placeholder for output_ in self.outputs_with_ids
    ]

    # Define Flask server
    server = flask.Flask(__name__)
    external_stylesheets = [
        theme_mapper(theme),
        "https://use.fontawesome.com/releases/v5.9.0/css/all.css",
    ]

    source = dash.Dash
    if self.mode is not None:
        try:
            from jupyter_dash import JupyterDash

            source = JupyterDash

        except ImportError as e:
            self.mode = None
            warnings.warn(str(e))
            warnings.warn("Ignoring mode argument")

    self.app = source(
        __name__,
        external_stylesheets=external_stylesheets,
        server=server,
        meta_tags=[
            {
                "name": "viewport",
                "content": "width=device-width, initial-scale=1.0, maximum-scale=1.8, minimum-scale=0.5",
            }
        ],
    )
    # Define app title
    self.app.title = self.title

    # Intialize layout
    self.set_layout()

    # Register callbacks
    self.register_callback_fn()

    # Keep track of the number of clicks
    self.submit_clicks = 0
    self.reset_clicks = 0
    self.app_initialized = False

    # Allow easier access to Dash server
    self.server = self.app.server

Fastify(component, component_property, ack=None, placeholder=None, label_=None)

Modify a Dash component to a FastComponent.

Parameters:

Name Type Description Default
component type required
component_property type required
ack type None
placeholder type None
label_ type None

Returns:

Type Description
Source code in fast_dash/utils.py
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def Fastify(component, component_property, ack=None, placeholder=None, label_=None):
    """
    Modify a Dash component to a FastComponent.

    Args:
        component (type):
        component_property (type):
        ack (type, optional):
        placeholder (type, optional):
        label_ (type, optional):

    Returns:
        [type]: [description]
    """

    component.component_property = component_property
    component.ack = ack
    component.label_ = label_
    component.placeholder = placeholder

    return component

fastdash(_callback_fn=None, *, inputs=None, outputs=None, title=None, title_image_path=None, subheader=None, github_url=None, linkedin_url=None, twitter_url=None, navbar=True, footer=True, theme='JOURNAL', update_live=False, mode=None, minimal=False, disable_logs=False, **run_kwargs)

Decorator for the FastDash class.

Use the decorated Python callback functions and deployes it using the chosen mode.

Parameters:

Name Type Description Default
callback_fn func

Python function that Fast Dash deploys. This function guides the behavior of and interaction between input and output components.

required
inputs Fast component, list of Fast components

Components to represent inputs of the callback function. Defaults to None. If None, Fast Dash attempts to infer the best components from callback function's type hints and default values. In the absence of type hints, default components are all Text.

None
outputs Fast component, list of Fast components

Components to represent outputs of the callback function. Defaults to None. If None, Fast Dash attempts to infer the best components from callback function's type hints. In the absence of type hints, default components are all Text.

None
title str

Title given to the app. Defaults to None. If None, function name (assumed to be in snake case) is converted to title case.

None
title_image_path str

Path (local or URL) of the app title image. Defaults to None.

None
subheader str

Subheader of the app, displayed below the title image and title. Defaults to None. If None, Fast Dash tries to use the callback function's docstring instead.

None
github_url str

GitHub URL for branding. Displays a GitHub logo in the navbar, which takes users to the specified URL. Defaults to None.

None
linkedin_url str

LinkedIn URL for branding Displays a LinkedIn logo in the navbar, which takes users to the specified URL. Defaults to None.

None
twitter_url str

Twitter URL for branding. Displays a Twitter logo in the navbar, which takes users to the specified URL. Defaults to None.

None
navbar bool

Display navbar. Defaults to True.

True
footer bool

Display footer. Defaults to True.

True
theme str

Apply theme to the app. Defaults to "JOURNAL". All available themes can be found at https://bootswatch.com/.

'JOURNAL'
update_live bool

Enable hot reloading. Defaults to False.

False
mode str

Mode in which to launch the app. Acceptable options are None, jupyterlab, inline, 'external`. Defaults to None.

None
minimal bool

Display minimal version by hiding navbar, title, title image, subheader and footer. Defaults to False.

False
disable_logs bool

Hide app logs. Sets logger level to ERROR. Defaults to False.

False
Source code in fast_dash/fast_dash.py
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def fastdash(
    _callback_fn=None,
    *,
    inputs=None,
    outputs=None,
    title=None,
    title_image_path=None,
    subheader=None,
    github_url=None,
    linkedin_url=None,
    twitter_url=None,
    navbar=True,
    footer=True,
    theme="JOURNAL",
    update_live=False,
    mode=None,
    minimal=False,
    disable_logs=False,
    **run_kwargs
):
    """
    Decorator for the `FastDash` class.

    Use the decorated Python callback functions and deployes it using the chosen mode.

    Args:
        callback_fn (func): Python function that Fast Dash deploys.
            This function guides the behavior of and interaction between input and output components.

        inputs (Fast component, list of Fast components, optional): Components to represent inputs of the callback function.
            Defaults to None. If `None`, Fast Dash attempts to infer the best components from callback function's type
            hints and default values. In the absence of type hints, default components are all `Text`.

        outputs (Fast component, list of Fast components, optional): Components to represent outputs of the callback function.
            Defaults to None. If `None`, Fast Dash attempts to infer the best components from callback function's type hints.
            In the absence of type hints, default components are all `Text`.

        title (str, optional): Title given to the app. Defaults to None. If `None`, function name (assumed to be in snake case)
            is converted to title case.

        title_image_path (str, optional): Path (local or URL) of the app title image. Defaults to None.

        subheader (str, optional): Subheader of the app, displayed below the title image and title. Defaults to None.
            If `None`, Fast Dash tries to use the callback function's docstring instead.

        github_url (str, optional): GitHub URL for branding. Displays a GitHub logo in the navbar, which takes users to the
            specified URL. Defaults to None.

        linkedin_url (str, optional): LinkedIn URL for branding Displays a LinkedIn logo in the navbar, which takes users to the
            specified URL. Defaults to None.

        twitter_url (str, optional): Twitter URL for branding. Displays a Twitter logo in the navbar, which takes users to the
            specified URL. Defaults to None.

        navbar (bool, optional): Display navbar. Defaults to True.

        footer (bool, optional): Display footer. Defaults to True.

        theme (str, optional): Apply theme to the app. Defaults to "JOURNAL". All available themes can be found
            at https://bootswatch.com/.

        update_live (bool, optional): Enable hot reloading. Defaults to False.

        mode (str, optional): Mode in which to launch the app. Acceptable options are `None`, `jupyterlab`, `inline`, 'external`.
            Defaults to None.

        minimal (bool, optional): Display minimal version by hiding navbar, title, title image, subheader and footer.
            Defaults to False.

        disable_logs (bool, optional): Hide app logs. Sets logger level to `ERROR`. Defaults to False.
    """

    def decorator_fastdash(callback_fn):
        "Decorator for callback_fn"

        @functools.wraps(callback_fn)
        def wrapper_fastdash(**kwargs):
            app = FastDash(callback_fn=callback_fn, **kwargs)
            app.run(**run_kwargs)
            return callback_fn

        return wrapper_fastdash(
            inputs=inputs,
            outputs=outputs,
            title=title,
            title_image_path=title_image_path,
            subheader=subheader,
            github_url=github_url,
            linkedin_url=linkedin_url,
            twitter_url=twitter_url,
            navbar=navbar,
            footer=footer,
            theme=theme,
            update_live=update_live,
            mode=mode,
            minimal=minimal,
            disable_logs=disable_logs,
            **run_kwargs
        )

    # If the decorator is called with arguments
    if _callback_fn is None:
        return decorator_fastdash
    # If the decorator is called without arguments. Use default input and output values
    else:
        return decorator_fastdash(_callback_fn)