Region managers provide a consistent way to manage a number of Marionette.Region objects within an application. The RegionManager is intended to be used by other objects, to facilitate the addition, storage, retrieval, and removal of regions from that object. For examples of how it can be used, see the Marionette.Application and Marionette.Layout objects.
RegionManagers can be instantiated directly, and can have regions added and removed via several methods:
var rm = new Marionette.RegionManager();
var region = rm.addRegion("foo", "#bar");
var regions = rm.addRegions({
baz: "#baz",
quux: "ul.quux"
});
regions.baz.show(myView);
rm.removeRegion("foo");
Regions can be added individually using the addRegion
method. This method takes two parameters: the region name
and the region definition.
var rm = new Marionette.RegionManager();
var region = rm.addRegion("foo", "#bar");
In this example, a region named "foo" will be added
to the RegionManager instance. It is defined as a
jQuery selector that will search for the #bar
element in the DOM.
There are a lot of other ways to define a region, including object literals with various options, and instances of Region objects. For more information on this, see the Region documentation.
Regions can also be added en-masse through the use
of the addRegions
method. To use this method,
pass an object literal that contains the names of
the regions as keys, and the region definitions as
values.
var rm = new Marionette.RegionManager();
var regions = rm.addRegions({
foo: "#bar",
bar: {
selector: "#quux",
regionType: MyRegionType
}
});
regions.foo; //=> the "foo" region instance
regions.bar; //=> the "bar" region instance
This method returns an object literal that contains all of the named region instances.
When adding multiple regions it may be useful to
provide a set of defaults that get applied to all
of the regions being added. This can be done through
the use of a defaults
parameter. Specify this
parameter as an object literal with key: value
pairs that will be applied to every region added.
var rm = new Marionette.RegionManager();
var defaults = {
regionType: MyRegionType
};
var regions = {
foo: "#bar",
baz: "#quux"
};
rm.addRegions(regions, defaults);
In this example, all regions will be added as
instances of MyRegionType
.
A region instance can be retrieved from the
RegionManager instance using the get
method and
passing in the name of the region.
var rm = new Marionette.RegionManager();
rm.addRegion("foo", "#bar");
var region = rm.get("foo");
A region can be removed by calling the removeRegion
method and passing in the name of the region.
var rm = new Marionette.RegionManager();
rm.addRegion("foo", "#bar");
rm.removeRegion("foo");
A region will have its close
method called before
it is removed from the RegionManager instance and
stopListening
is called.
You can quickly remove all regions from the
RegionManager instance by calling the removeRegions
method.
var rm = new Marionette.RegionManager();
rm.addRegions({
foo: "#foo",
bar: "#bar",
baz: "#baz"
});
rm.removeRegions();
This will close all regions, and remove them.
You can quickly close all regions from the RegionManager
instance by calling the closeRegions
method.
var rm = new Marionette.RegionManager();
rm.addRegions({
foo: "#foo",
bar: "#bar",
baz: "#baz"
});
rm.closeRegions();
This will close the regions without removing them from the RegionManager instance.
A RegionManager instance can be closed entirely by
calling the close
method. This will both close
and remove all regions from the RegionManager instance.
var rm = new Marionette.RegionManager();
rm.addRegions({
foo: "#foo",
bar: "#bar",
baz: "#baz"
});
rm.close();
A RegionManager will trigger various events as it is being used.
The RegionManager will trigger a "region:add" event when a region is added to the manager. This allows you to use the region instance immediately, or attach the region to an object that needs a reference to it:
var rm = new Marionette.RegionManager();
rm.on("region:add", function(name, region){
// add the region instance to an object
myObject[name] = region;
});
rm.addRegion("foo", "#bar");
The RegionManager will trigger a "region:remove" event when a region is removed from the manager. This allows you to use the region instance one last time, or remove the region from an object that has a reference to it:
var rm = new Marionette.RegionManager();
rm.on("region:remove", function(name, region){
// add the region instance to an object
delete myObject[name];
});
rm.addRegion("foo", "#bar");
rm.removeRegion("foo");
The RegionManager has several methods for iteration
attached to it, from underscore.js. This works in the
same way as the Backbone.Collection methods that have
been imported. For example, you can easily iterate over
the entire collection of region instances by calling
the each
method:
var rm = new Marionette.RegionManager();
rm.each(function(region){
// do stuff w/ the region instance here
});
The list of underscore methods includes: