我总是对视图进行核处理,有时还会重用模型。如果您保留模型,确保视图被释放可能会很痛苦。如果模型没有正确绑定,它们可能会保留对视图的引用。
从 Backbone ~0.9.9 开始,使用 view.listenTo() 而不是 model.on() 绑定模型允许通过控制反转(视图控制绑定而不是模型)更容易地清理。如果使用 view.listenTo() 进行绑定,则调用 view.stopListening() 或 view.remove() 将删除所有绑定。类似于调用model.off(null, null, this)。
我喜欢通过使用半自动调用子视图的关闭函数扩展视图来清理视图。子视图必须由父视图的属性引用,或者它们必须添加到父视图中名为 childViews[] 的数组中。
这是我使用的关闭功能..
// fired by the router, signals the destruct event within top view and
// recursively collapses all the sub-views that are stored as properties
Backbone.View.prototype.close = function () {
// calls views closing event handler first, if implemented (optional)
if (this.closing) {
this.closing(); // this for custom cleanup purposes
}
// first loop through childViews[] if defined, in collection views
// populate an array property i.e. this.childViews[] = new ControlViews()
if (this.childViews) {
_.each(this.childViews, function (child) {
child.close();
});
}
// close all child views that are referenced by property, in model views
// add a property for reference i.e. this.toolbar = new ToolbarView();
for (var prop in this) {
if (this[prop] instanceof Backbone.View) {
this[prop].close();
}
}
this.unbind();
this.remove();
// available in Backbone 0.9.9 + when using view.listenTo,
// removes model and collection bindings
// this.stopListening(); // its automatically called by remove()
// remove any model bindings to this view
// (pre Backbone 0.9.9 or if using model.on to bind events)
// if (this.model) {
// this.model.off(null, null, this);
// }
// remove and collection bindings to this view
// (pre Backbone 0.9.9 or if using collection.on to bind events)
// if (this.collection) {
// this.collection.off(null, null, this);
// }
}
然后声明一个视图如下..
views.TeamView = Backbone.View.extend({
initialize: function () {
// instantiate this array to ensure sub-view destruction on close()
this.childViews = [];
this.listenTo(this.collection, "add", this.add);
this.listenTo(this.collection, "reset", this.reset);
// storing sub-view as a property will ensure destruction on close()
this.editView = new views.EditView({ model: this.model.edits });
$('#edit', this.el).html(this.editView.render().el);
},
add: function (member) {
var memberView = new views.MemberView({ model: member });
this.childViews.push(memberView); // add child to array
var item = memberView.render().el;
this.$el.append(item);
},
reset: function () {
// manually purge child views upon reset
_.each(this.childViews, function (child) {
child.close();
});
this.childViews = [];
},
// render is called externally and should handle case where collection
// was already populated, as is the case if it is recycled
render: function () {
this.$el.empty();
_.each(this.collection.models, function (member) {
this.add(member);
}, this);
return this;
}
// fired by a prototype extension
closing: function () {
// handle other unbinding needs, here
}
});