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manager.js
464 lines | 18.5 KiB | application/javascript | JavascriptLexer
// Copyright (c) IPython Development Team.
// Distributed under the terms of the Modified BSD License.
define([
"underscore",
"backbone",
"jquery",
"base/js/utils",
"base/js/namespace",
"services/kernels/comm"
], function (_, Backbone, $, utils, IPython, comm) {
"use strict";
//--------------------------------------------------------------------
// WidgetManager class
//--------------------------------------------------------------------
var WidgetManager = function (comm_manager, notebook) {
/**
* Public constructor
*/
WidgetManager._managers.push(this);
// Attach a comm manager to the
this.keyboard_manager = notebook.keyboard_manager;
this.notebook = notebook;
this.comm_manager = comm_manager;
this.comm_target_name = 'ipython.widget';
this._models = {}; /* Dictionary of model ids and model instance promises */
// Register with the comm manager.
this.comm_manager.register_target(this.comm_target_name, $.proxy(this._handle_comm_open, this));
// Load the initial state of the widget manager if a load callback was
// registered.
var that = this;
if (WidgetManager._load_callback) {
Promise.resolve(WidgetManager._load_callback.call(this)).then(function(state) {
that.set_state(state);
}).catch(utils.reject('Error loading widget manager state', true));
}
// Setup state saving code.
this.notebook.events.on('before_save.Notebook', function() {
var save_callback = WidgetManager._save_callback;
var options = WidgetManager._get_state_options;
if (save_callback) {
that.get_state(options).then(function(state) {
save_callback.call(that, state);
}).catch(utils.reject('Could not call widget save state callback.', true));
}
});
};
//--------------------------------------------------------------------
// Class level
//--------------------------------------------------------------------
WidgetManager._model_types = {}; /* Dictionary of model type names (target_name) and model types. */
WidgetManager._view_types = {}; /* Dictionary of view names and view types. */
WidgetManager._managers = []; /* List of widget managers */
WidgetManager._load_callback = null;
WidgetManager._save_callback = null;
WidgetManager.register_widget_model = function (model_name, model_type) {
/**
* Registers a widget model by name.
*/
WidgetManager._model_types[model_name] = model_type;
};
WidgetManager.register_widget_view = function (view_name, view_type) {
/**
* Registers a widget view by name.
*/
WidgetManager._view_types[view_name] = view_type;
};
WidgetManager.set_state_callbacks = function (load_callback, save_callback, options) {
/**
* Registers callbacks for widget state persistence.
*
* Parameters
* ----------
* load_callback: function()
* function that is called when the widget manager state should be
* loaded. This function should return a promise for the widget
* manager state. An empty state is an empty dictionary `{}`.
* save_callback: function(state as dictionary)
* function that is called when the notebook is saved or autosaved.
* The current state of the widget manager is passed in as the first
* argument.
*/
WidgetManager._load_callback = load_callback;
WidgetManager._save_callback = save_callback;
WidgetManager._get_state_options = options;
// Use the load callback to immediately load widget states.
WidgetManager._managers.forEach(function(manager) {
if (load_callback) {
Promise.resolve(load_callback.call(manager)).then(function(state) {
manager.set_state(state);
}).catch(utils.reject('Error loading widget manager state', true));
}
});
};
//--------------------------------------------------------------------
// Instance level
//--------------------------------------------------------------------
WidgetManager.prototype.display_view = function(msg, model) {
/**
* Displays a view for a particular model.
*/
var cell = this.get_msg_cell(msg.parent_header.msg_id);
if (cell === null) {
return Promise.reject(new Error("Could not determine where the display" +
" message was from. Widget will not be displayed"));
} else {
return this.display_view_in_cell(cell, model)
.catch(utils.reject('Could not display view', true));
}
};
WidgetManager.prototype.display_view_in_cell = function(cell, model) {
// Displays a view in a cell.
if (cell.display_widget_view) {
var that = this;
return cell.display_widget_view(this.create_view(model, {
cell: cell,
// Only set cell_index when view is displayed as directly.
cell_index: that.notebook.find_cell_index(cell),
})).then(function(view) {
that._handle_display_view(view);
view.trigger('displayed');
return view;
}).catch(utils.reject('Could not create or display view', true));
} else {
return Promise.reject(new Error('Cell does not have a `display_widget_view` method'));
}
};
WidgetManager.prototype._handle_display_view = function (view) {
/**
* Have the IPython keyboard manager disable its event
* handling so the widget can capture keyboard input.
* Note, this is only done on the outer most widgets.
*/
if (this.keyboard_manager) {
this.keyboard_manager.register_events(view.$el);
if (view.additional_elements) {
for (var i = 0; i < view.additional_elements.length; i++) {
this.keyboard_manager.register_events(view.additional_elements[i]);
}
}
}
};
WidgetManager.prototype.create_view = function(model, options) {
/**
* Creates a promise for a view of a given model
*
* Make sure the view creation is not out of order with
* any state updates.
*/
model.state_change = model.state_change.then(function() {
return utils.load_class(model.get('_view_name'), model.get('_view_module'),
WidgetManager._view_types).then(function(ViewType) {
// If a view is passed into the method, use that view's cell as
// the cell for the view that is created.
options = options || {};
if (options.parent !== undefined) {
options.cell = options.parent.options.cell;
}
// Create and render the view...
var parameters = {model: model, options: options};
var view = new ViewType(parameters);
view.listenTo(model, 'destroy', view.remove);
return Promise.resolve(view.render()).then(function() {return view;});
}).catch(utils.reject("Couldn't create a view for model id '" + String(model.id) + "'", true));
});
var id = utils.uuid();
model.views[id] = model.state_change;
model.state_change.then(function(view) {
view.once('remove', function() {
delete view.model.views[id];
}, this);
});
return model.state_change;
};
WidgetManager.prototype.get_msg_cell = function (msg_id) {
var cell = null;
// First, check to see if the msg was triggered by cell execution.
if (this.notebook) {
cell = this.notebook.get_msg_cell(msg_id);
}
if (cell !== null) {
return cell;
}
// Second, check to see if a get_cell callback was defined
// for the message. get_cell callbacks are registered for
// widget messages, so this block is actually checking to see if the
// message was triggered by a widget.
var kernel = this.comm_manager.kernel;
if (kernel) {
var callbacks = kernel.get_callbacks_for_msg(msg_id);
if (callbacks && callbacks.iopub &&
callbacks.iopub.get_cell !== undefined) {
return callbacks.iopub.get_cell();
}
}
// Not triggered by a cell or widget (no get_cell callback
// exists).
return null;
};
WidgetManager.prototype.callbacks = function (view) {
/**
* callback handlers specific a view
*/
var callbacks = {};
if (view && view.options.cell) {
// Try to get output handlers
var cell = view.options.cell;
var handle_output = null;
var handle_clear_output = null;
if (cell.output_area) {
handle_output = $.proxy(cell.output_area.handle_output, cell.output_area);
handle_clear_output = $.proxy(cell.output_area.handle_clear_output, cell.output_area);
}
// Create callback dictionary using what is known
var that = this;
callbacks = {
iopub : {
output : handle_output,
clear_output : handle_clear_output,
// Special function only registered by widget messages.
// Allows us to get the cell for a message so we know
// where to add widgets if the code requires it.
get_cell : function () {
return cell;
},
},
};
}
return callbacks;
};
WidgetManager.prototype.get_model = function (model_id) {
/**
* Get a promise for a model by model id.
*/
return this._models[model_id];
};
WidgetManager.prototype._handle_comm_open = function (comm, msg) {
/**
* Handle when a comm is opened.
*/
return this.create_model({
model_name: msg.content.data.model_name,
model_module: msg.content.data.model_module,
comm: comm}).catch(utils.reject("Couldn't create a model.", true));
};
WidgetManager.prototype.create_model = function (options) {
/**
* Create and return a promise for a new widget model
*
* Minimally, one must provide the model_name and widget_class
* parameters to create a model from Javascript.
*
* Example
* --------
* JS:
* IPython.notebook.kernel.widget_manager.create_model({
* model_name: 'WidgetModel',
* widget_class: 'IPython.html.widgets.widget_int.IntSlider'})
* .then(function(model) { console.log('Create success!', model); },
* $.proxy(console.error, console));
*
* Parameters
* ----------
* options: dictionary
* Dictionary of options with the following contents:
* model_name: string
* Target name of the widget model to create.
* model_module: (optional) string
* Module name of the widget model to create.
* widget_class: (optional) string
* Target name of the widget in the back-end.
* comm: (optional) Comm
*
* Create a comm if it wasn't provided.
*/
var comm = options.comm;
if (!comm) {
comm = this.comm_manager.new_comm('ipython.widget', {'widget_class': options.widget_class});
}
var that = this;
var model_id = comm.comm_id;
var model_promise = utils.load_class(options.model_name, options.model_module, WidgetManager._model_types)
.then(function(ModelType) {
var widget_model = new ModelType(that, model_id, comm);
widget_model.once('comm:close', function () {
delete that._models[model_id];
});
widget_model.name = options.model_name;
widget_model.module = options.model_module;
return widget_model;
}, function(error) {
delete that._models[model_id];
var wrapped_error = new utils.WrappedError("Couldn't create model", error);
return Promise.reject(wrapped_error);
});
this._models[model_id] = model_promise;
return model_promise;
};
WidgetManager.prototype.get_state = function(options) {
/**
* Asynchronously get the state of the widget manager.
*
* This includes all of the widget models and the cells that they are
* displayed in.
*
* Parameters
* ----------
* options: dictionary
* Dictionary of options with the following contents:
* only_displayed: (optional) boolean=false
* Only return models with one or more displayed views.
* not_live: (optional) boolean=false
* Include models that have comms with severed connections.
*
* Returns
* -------
* Promise for a state dictionary
*/
var that = this;
return utils.resolve_promises_dict(this._models).then(function(models) {
var state = {};
for (var model_id in models) {
if (models.hasOwnProperty(model_id)) {
var model = models[model_id];
// If the model has one or more views defined for it,
// consider it displayed.
var displayed_flag = !(options && options.only_displayed) || Object.keys(model.views).length > 0;
var live_flag = (options && options.not_live) || model.comm_live;
if (displayed_flag && live_flag) {
state[model_id] = {
model_name: model.name,
model_module: model.module,
state: model.get_state(),
views: [],
};
// Get the views that are displayed *now*.
for (var id in model.views) {
if (model.views.hasOwnProperty(id)) {
var view = model.views[id];
if (view.options.cell_index) {
state[model_id].views.push(view.options.cell_index);
}
}
}
}
}
}
return state;
}).catch(utils.reject('Could not get state of widget manager', true));
};
WidgetManager.prototype.set_state = function(state) {
/**
* Set the notebook's state.
*
* Reconstructs all of the widget models and attempts to redisplay the
* widgets in the appropriate cells by cell index.
*/
// Get the kernel when it's available.
var that = this;
return this._get_connected_kernel().then(function(kernel) {
// Recreate all the widget models for the given state and
// display the views.
that.all_views = [];
var model_ids = Object.keys(state);
for (var i = 0; i < model_ids.length; i++) {
var model_id = model_ids[i];
// Recreate a comm using the widget's model id (model_id == comm_id).
var new_comm = new comm.Comm(kernel.widget_manager.comm_target_name, model_id);
kernel.comm_manager.register_comm(new_comm);
// Create the model using the recreated comm. When the model is
// created we don't know yet if the comm is valid so set_comm_live
// false. Once we receive the first state push from the back-end
// we know the comm is alive.
var views = kernel.widget_manager.create_model({
comm: new_comm,
model_name: state[model_id].model_name,
model_module: state[model_id].model_module})
.then(function(model) {
model.set_comm_live(false);
var view_promise = Promise.resolve().then(function() {
return model.set_state(state[model.id].state);
}).then(function() {
model.request_state().then(function() {
model.set_comm_live(true);
});
// Display the views of the model.
var views = [];
var model_views = state[model.id].views;
for (var j=0; j<model_views.length; j++) {
var cell_index = model_views[j];
var cell = that.notebook.get_cell(cell_index);
views.push(that.display_view_in_cell(cell, model));
}
return Promise.all(views);
});
return view_promise;
});
that.all_views.push(views);
}
return Promise.all(that.all_views);
}).catch(utils.reject('Could not set widget manager state.', true));
};
WidgetManager.prototype._get_connected_kernel = function() {
/**
* Gets a promise for a connected kernel
*/
var that = this;
return new Promise(function(resolve, reject) {
if (that.comm_manager &&
that.comm_manager.kernel &&
that.comm_manager.kernel.is_connected()) {
resolve(that.comm_manager.kernel);
} else {
that.notebook.events.on('kernel_connected.Kernel', function(event, data) {
resolve(data.kernel);
});
}
});
};
// Backwards compatibility.
IPython.WidgetManager = WidgetManager;
return {'WidgetManager': WidgetManager};
});