// Region
// ------
//
// Manage the visual regions of your composite application. See
// http://lostechies.com/derickbailey/2011/12/12/composite-js-apps-regions-and-region-managers/
Marionette.Region = function(options){
this.options = options || {};
this.el = Marionette.getOption(this, "el");
if (!this.el){
var err = new Error("An 'el' must be specified for a region.");
err.name = "NoElError";
throw err;
}
if (this.initialize){
var args = Array.prototype.slice.apply(arguments);
this.initialize.apply(this, args);
}
};
// Region Type methods
// -------------------
_.extend(Marionette.Region, {
// Build an instance of a region by passing in a configuration object
// and a default region type to use if none is specified in the config.
//
// The config object should either be a string as a jQuery DOM selector,
// a Region type directly, or an object literal that specifies both
// a selector and regionType:
//
// ```js
// {
// selector: "#foo",
// regionType: MyCustomRegion
// }
// ```
//
buildRegion: function(regionConfig, defaultRegionType){
var regionIsString = (typeof regionConfig === "string");
var regionSelectorIsString = (typeof regionConfig.selector === "string");
var regionTypeIsUndefined = (typeof regionConfig.regionType === "undefined");
var regionIsType = (typeof regionConfig === "function");
Iif (!regionIsType && !regionIsString && !regionSelectorIsString) {
throw new Error("Region must be specified as a Region type, a selector string or an object with selector property");
}
var selector, RegionType;
// get the selector for the region
if (regionIsString) {
selector = regionConfig;
}
if (regionConfig.selector) {
selector = regionConfig.selector;
}
// get the type for the region
if (regionIsType){
RegionType = regionConfig;
}
if (!regionIsType && regionTypeIsUndefined) {
RegionType = defaultRegionType;
}
if (regionConfig.regionType) {
RegionType = regionConfig.regionType;
}
// build the region instance
var region = new RegionType({
el: selector
});
// override the `getEl` function if we have a parentEl
// this must be overridden to ensure the selector is found
// on the first use of the region. if we try to assign the
// region's `el` to `parentEl.find(selector)` in the object
// literal to build the region, the element will not be
// guaranteed to be in the DOM already, and will cause problems
if (regionConfig.parentEl){
region.getEl = function(selector) {
var parentEl = regionConfig.parentEl;
if (_.isFunction(parentEl)){
parentEl = parentEl();
}
return parentEl.find(selector);
};
}
return region;
}
});
// Region Instance Methods
// -----------------------
_.extend(Marionette.Region.prototype, Backbone.Events, {
// Displays a backbone view instance inside of the region.
// Handles calling the `render` method for you. Reads content
// directly from the `el` attribute. Also calls an optional
// `onShow` and `close` method on your view, just after showing
// or just before closing the view, respectively.
show: function(view){
this.ensureEl();
var isViewClosed = view.isClosed || _.isUndefined(view.$el);
var isDifferentView = view !== this.currentView;
if (isDifferentView) {
this.close();
}
view.render();
if (isDifferentView || isViewClosed) {
this.open(view);
}
this.currentView = view;
Marionette.triggerMethod.call(this, "show", view);
Marionette.triggerMethod.call(view, "show");
},
ensureEl: function(){
if (!this.$el || this.$el.length === 0){
this.$el = this.getEl(this.el);
}
},
// Override this method to change how the region finds the
// DOM element that it manages. Return a jQuery selector object.
getEl: function(selector){
return Marionette.$(selector);
},
// Override this method to change how the new view is
// appended to the `$el` that the region is managing
open: function(view){
this.$el.empty().append(view.el);
},
// Close the current view, if there is one. If there is no
// current view, it does nothing and returns immediately.
close: function(){
var view = this.currentView;
if (!view || view.isClosed){ return; }
// call 'close' or 'remove', depending on which is found
if (view.close) { view.close(); }
else Eif (view.remove) { view.remove(); }
Marionette.triggerMethod.call(this, "close");
delete this.currentView;
},
// Attach an existing view to the region. This
// will not call `render` or `onShow` for the new view,
// and will not replace the current HTML for the `el`
// of the region.
attachView: function(view){
this.currentView = view;
},
// Reset the region by closing any existing view and
// clearing out the cached `$el`. The next time a view
// is shown via this region, the region will re-query the
// DOM for the region's `el`.
reset: function(){
this.close();
delete this.$el;
}
});
// Copy the `extend` function used by Backbone's classes
Marionette.Region.extend = Marionette.extend;
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