##// END OF EJS Templates
allow async output on the most recent request...
allow async output on the most recent request Keeps track of the most recent request, so async output is still allowed

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widget.js
451 lines | 16.5 KiB | application/javascript | JavascriptLexer
//----------------------------------------------------------------------------
// Copyright (C) 2013 The IPython Development Team
//
// Distributed under the terms of the BSD License. The full license is in
// the file COPYING, distributed as part of this software.
//----------------------------------------------------------------------------
//============================================================================
// Base Widget Model and View classes
//============================================================================
/**
* @module IPython
* @namespace IPython
**/
define(["widgets/js/manager",
"underscore",
"backbone"],
function(WidgetManager, _, Backbone){
var WidgetModel = Backbone.Model.extend({
constructor: function (widget_manager, model_id, comm) {
// Constructor
//
// Creates a WidgetModel instance.
//
// Parameters
// ----------
// widget_manager : WidgetManager instance
// model_id : string
// An ID unique to this model.
// comm : Comm instance (optional)
this.widget_manager = widget_manager;
this._buffered_state_diff = {};
this.pending_msgs = 0;
this.msg_buffer = null;
this.key_value_lock = null;
this.id = model_id;
this.views = [];
if (comm !== undefined) {
// Remember comm associated with the model.
this.comm = comm;
comm.model = this;
// Hook comm messages up to model.
comm.on_close($.proxy(this._handle_comm_closed, this));
comm.on_msg($.proxy(this._handle_comm_msg, this));
}
return Backbone.Model.apply(this);
},
send: function (content, callbacks) {
// Send a custom msg over the comm.
if (this.comm !== undefined) {
var data = {method: 'custom', content: content};
this.comm.send(data, callbacks);
this.pending_msgs++;
}
},
_handle_comm_closed: function (msg) {
// Handle when a widget is closed.
this.trigger('comm:close');
delete this.comm.model; // Delete ref so GC will collect widget model.
delete this.comm;
delete this.model_id; // Delete id from model so widget manager cleans up.
_.each(this.views, function(view, i) {
view.remove();
});
},
_handle_comm_msg: function (msg) {
// Handle incoming comm msg.
var method = msg.content.data.method;
switch (method) {
case 'update':
this.apply_update(msg.content.data.state);
break;
case 'custom':
this.trigger('msg:custom', msg.content.data.content);
break;
case 'display':
this.widget_manager.display_view(msg, this);
this.trigger('displayed');
break;
}
},
apply_update: function (state) {
// Handle when a widget is updated via the python side.
var that = this;
_.each(state, function(value, key) {
that.key_value_lock = [key, value];
try {
WidgetModel.__super__.set.apply(that, [key, that._unpack_models(value)]);
} finally {
that.key_value_lock = null;
}
});
},
_handle_status: function (msg, callbacks) {
// Handle status msgs.
// execution_state : ('busy', 'idle', 'starting')
if (this.comm !== undefined) {
if (msg.content.execution_state ==='idle') {
// Send buffer if this message caused another message to be
// throttled.
if (this.msg_buffer !== null &&
(this.get('msg_throttle') || 3) === this.pending_msgs) {
var data = {method: 'backbone', sync_method: 'update', sync_data: this.msg_buffer};
this.comm.send(data, callbacks);
this.msg_buffer = null;
} else {
--this.pending_msgs;
}
}
}
},
callbacks: function(view) {
// Create msg callbacks for a comm msg.
var callbacks = this.widget_manager.callbacks(view);
if (callbacks.iopub === undefined) {
callbacks.iopub = {};
}
var that = this;
callbacks.iopub.status = function (msg) {
that._handle_status(msg, callbacks);
};
return callbacks;
},
set: function(key, val, options) {
// Set a value.
var return_value = WidgetModel.__super__.set.apply(this, arguments);
// Backbone only remembers the diff of the most recent set()
// operation. Calling set multiple times in a row results in a
// loss of diff information. Here we keep our own running diff.
this._buffered_state_diff = $.extend(this._buffered_state_diff, this.changedAttributes() || {});
return return_value;
},
sync: function (method, model, options) {
// Handle sync to the back-end. Called when a model.save() is called.
// Make sure a comm exists.
var error = options.error || function() {
console.error('Backbone sync error:', arguments);
};
if (this.comm === undefined) {
error();
return false;
}
// Delete any key value pairs that the back-end already knows about.
var attrs = (method === 'patch') ? options.attrs : model.toJSON(options);
if (this.key_value_lock !== null) {
var key = this.key_value_lock[0];
var value = this.key_value_lock[1];
if (attrs[key] === value) {
delete attrs[key];
}
}
// Only sync if there are attributes to send to the back-end.
attrs = this._pack_models(attrs);
if (_.size(attrs) > 0) {
// If this message was sent via backbone itself, it will not
// have any callbacks. It's important that we create callbacks
// so we can listen for status messages, etc...
var callbacks = options.callbacks || this.callbacks();
// Check throttle.
if (this.pending_msgs >= (this.get('msg_throttle') || 3)) {
// The throttle has been exceeded, buffer the current msg so
// it can be sent once the kernel has finished processing
// some of the existing messages.
// Combine updates if it is a 'patch' sync, otherwise replace updates
switch (method) {
case 'patch':
this.msg_buffer = $.extend(this.msg_buffer || {}, attrs);
break;
case 'update':
case 'create':
this.msg_buffer = attrs;
break;
default:
error();
return false;
}
this.msg_buffer_callbacks = callbacks;
} else {
// We haven't exceeded the throttle, send the message like
// normal.
var data = {method: 'backbone', sync_data: attrs};
this.comm.send(data, callbacks);
this.pending_msgs++;
}
}
// Since the comm is a one-way communication, assume the message
// arrived. Don't call success since we don't have a model back from the server
// this means we miss out on the 'sync' event.
this._buffered_state_diff = {};
},
save_changes: function(callbacks) {
// Push this model's state to the back-end
//
// This invokes a Backbone.Sync.
this.save(this._buffered_state_diff, {patch: true, callbacks: callbacks});
},
_pack_models: function(value) {
// Replace models with model ids recursively.
if (value instanceof Backbone.Model) {
return value.id;
} else if ($.isArray(value)) {
var packed = [];
var that = this;
_.each(value, function(sub_value, key) {
packed.push(that._pack_models(sub_value));
});
return packed;
} else if (value instanceof Object) {
var packed = {};
var that = this;
_.each(value, function(sub_value, key) {
packed[key] = that._pack_models(sub_value);
});
return packed;
} else {
return value;
}
},
_unpack_models: function(value) {
// Replace model ids with models recursively.
if ($.isArray(value)) {
var unpacked = [];
var that = this;
_.each(value, function(sub_value, key) {
unpacked.push(that._unpack_models(sub_value));
});
return unpacked;
} else if (value instanceof Object) {
var unpacked = {};
var that = this;
_.each(value, function(sub_value, key) {
unpacked[key] = that._unpack_models(sub_value);
});
return unpacked;
} else {
var model = this.widget_manager.get_model(value);
if (model) {
return model;
} else {
return value;
}
}
},
});
WidgetManager.register_widget_model('WidgetModel', WidgetModel);
var WidgetView = Backbone.View.extend({
initialize: function(parameters) {
// Public constructor.
this.model.on('change',this.update,this);
this.options = parameters.options;
this.child_views = [];
this.model.views.push(this);
},
update: function(){
// Triggered on model change.
//
// Update view to be consistent with this.model
},
create_child_view: function(child_model, options) {
// Create and return a child view.
//
// -given a model and (optionally) a view name if the view name is
// not given, it defaults to the model's default view attribute.
// TODO: this is hacky, and makes the view depend on this cell attribute and widget manager behavior
// it would be great to have the widget manager add the cell metadata
// to the subview without having to add it here.
var child_view = this.model.widget_manager.create_view(child_model, options || {}, this);
this.child_views[child_model.id] = child_view;
return child_view;
},
delete_child_view: function(child_model, options) {
// Delete a child view that was previously created using create_child_view.
var view = this.child_views[child_model.id];
if (view !== undefined) {
delete this.child_views[child_model.id];
view.remove();
}
},
do_diff: function(old_list, new_list, removed_callback, added_callback) {
// Difference a changed list and call remove and add callbacks for
// each removed and added item in the new list.
//
// Parameters
// ----------
// old_list : array
// new_list : array
// removed_callback : Callback(item)
// Callback that is called for each item removed.
// added_callback : Callback(item)
// Callback that is called for each item added.
// removed items
_.each(_.difference(old_list, new_list), function(item, index, list) {
removed_callback(item);
}, this);
// added items
_.each(_.difference(new_list, old_list), function(item, index, list) {
added_callback(item);
}, this);
},
callbacks: function(){
// Create msg callbacks for a comm msg.
return this.model.callbacks(this);
},
render: function(){
// Render the view.
//
// By default, this is only called the first time the view is created
},
send: function (content) {
// Send a custom msg associated with this view.
this.model.send(content, this.callbacks());
},
touch: function () {
this.model.save_changes(this.callbacks());
},
});
var DOMWidgetView = WidgetView.extend({
initialize: function (options) {
// Public constructor
// In the future we may want to make changes more granular
// (e.g., trigger on visible:change).
this.model.on('change', this.update, this);
this.model.on('msg:custom', this.on_msg, this);
DOMWidgetView.__super__.initialize.apply(this, arguments);
},
on_msg: function(msg) {
// Handle DOM specific msgs.
switch(msg.msg_type) {
case 'add_class':
this.add_class(msg.selector, msg.class_list);
break;
case 'remove_class':
this.remove_class(msg.selector, msg.class_list);
break;
}
},
add_class: function (selector, class_list) {
// Add a DOM class to an element.
this._get_selector_element(selector).addClass(class_list);
},
remove_class: function (selector, class_list) {
// Remove a DOM class from an element.
this._get_selector_element(selector).removeClass(class_list);
},
update: function () {
// Update the contents of this view
//
// Called when the model is changed. The model may have been
// changed by another view or by a state update from the back-end.
// The very first update seems to happen before the element is
// finished rendering so we use setTimeout to give the element time
// to render
var e = this.$el;
var visible = this.model.get('visible');
setTimeout(function() {e.toggle(visible);},0);
var css = this.model.get('_css');
if (css === undefined) {return;}
var that = this;
_.each(css, function(css_traits, selector){
// Apply the css traits to all elements that match the selector.
var elements = that._get_selector_element(selector);
if (elements.length > 0) {
_.each(css_traits, function(css_value, css_key){
elements.css(css_key, css_value);
});
}
});
},
_get_selector_element: function (selector) {
// Get the elements via the css selector.
// If the selector is blank, apply the style to the $el_to_style
// element. If the $el_to_style element is not defined, use apply
// the style to the view's element.
var elements;
if (!selector) {
if (this.$el_to_style === undefined) {
elements = this.$el;
} else {
elements = this.$el_to_style;
}
} else {
elements = this.$el.find(selector);
}
return elements;
},
});
IPython.WidgetModel = WidgetModel;
IPython.WidgetView = WidgetView;
IPython.DOMWidgetView = DOMWidgetView;
// Pass through WidgetManager namespace.
return WidgetManager;
});