refactor(core): rename ViewContainer to ViewContainerRef
This also renames InternalAppViewContainer into AppViewContainer Related to #1477 Closes #1554
This commit is contained in:
@@ -2,24 +2,24 @@
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## Overview
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This document explains the concept of a View.
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A View is a core primitive used by angular to render the DOM tree.
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This document explains the concept of a View.
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A View is a core primitive used by angular to render the DOM tree.
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A ViewPort is location in a View which can accept child Views.
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Every ViewPort has an associated ViewContainer than can contain any number of child Views.
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Every ViewPort has an associated ViewContainerRef than can contain any number of child Views.
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Views form a tree structure which mimics the DOM tree.
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* View is a core rendering construct. A running application is just a collection of Views which are
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nested in a tree like structure. The View tree is a simplified version of the DOM tree. A View can
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have a single DOM Element or large DOM structures. The key is that the DOM tree in the View can
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* View is a core rendering construct. A running application is just a collection of Views which are
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nested in a tree like structure. The View tree is a simplified version of the DOM tree. A View can
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have a single DOM Element or large DOM structures. The key is that the DOM tree in the View can
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not undergo structural changes (only property changes).
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* Views represent a running instance of a DOM View. This implies that while elements in a View
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can change properties, they can not change structurally. (Structural changes such as, adding or
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* Views represent a running instance of a DOM View. This implies that while elements in a View
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can change properties, they can not change structurally. (Structural changes such as, adding or
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removing elements requires adding or removing child Views into ViewContainers).
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* View can have zero or more ViewPorts. A ViewPort is a marker in the DOM which allows
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* View can have zero or more ViewPorts. A ViewPort is a marker in the DOM which allows
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the insertion of child Views.
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* Views are created from a ProtoView. A ProtoView is a compiled DOM View which is efficient at
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* Views are created from a ProtoView. A ProtoView is a compiled DOM View which is efficient at
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creating Views.
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* View contains a context object. The context represents the object instance against which all
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* View contains a context object. The context represents the object instance against which all
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expressions are evaluated.
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* View contains a ChangeDetector for looking for detecting changes to the model.
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* View contains ElementInjector for creating Directives.
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@@ -51,9 +51,9 @@ And assume following HTML View:
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</div>
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```
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The above template is compiled by the Compiler to create a ProtoView. The ProtoView is then used to
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create an instance of the View. The instantiation process involves cloning the above template and
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locating all of the elements which contain bindings and finally instantiating the Directives
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The above template is compiled by the Compiler to create a ProtoView. The ProtoView is then used to
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create an instance of the View. The instantiation process involves cloning the above template and
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locating all of the elements which contain bindings and finally instantiating the Directives
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associated with the template. (See compilation for more details.)
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```
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@@ -81,13 +81,13 @@ Note:
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* View knows which expressions need to be watched.
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* View knows what needs to be updated if the watched expression changes.
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* All DOM elements are owned by single instance of the view.
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* The structure of the DOM can not change during runtime. To allow structural changes to the DOM we need
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* The structure of the DOM can not change during runtime. To allow structural changes to the DOM we need
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to understand Composed View.
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## Composed View
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An important part of an application is to be able to change the DOM structure to render data for the
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An important part of an application is to be able to change the DOM structure to render data for the
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user. In Angular this is done by inserting child views into the ViewPort.
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Let's start with a View such as:
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@@ -123,12 +123,12 @@ The next step is to compose these two ProtoViews into an actual view which is re
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</ul> | viewA(someContext)
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```
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*Step2:* Instantiate `Foreach` directive which will receive the `ViewContainer`. (The ViewContainer
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*Step2:* Instantiate `Foreach` directive which will receive the `ViewContainerRef`. (The ViewContainerRef
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has a reference to `protoViewA`).
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*Step3:* As the `Foreach` directive unrolls it asks the `ViewContainer` to instantiate `protoViewB` and insert
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it after the `ViewPort` anchor. This is repeated for each `person` in `people`. Notice that
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*Step3:* As the `Foreach` directive unrolls it asks the `ViewContainerRef` to instantiate `protoViewB` and insert
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it after the `ViewPort` anchor. This is repeated for each `person` in `people`. Notice that
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```
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<ul> | viewA(someContext)
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@@ -138,9 +138,9 @@ it after the `ViewPort` anchor. This is repeated for each `person` in `people`.
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</ul> | viewA(someContext)
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```
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*Step4:* All of the bindings in the child Views are updated. Notice that in the case of `Foreach`
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the evaluation context for the `viewB0` and `viewB1` are `locals0` and `locals1` respectively.
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Locals allow the introduction of new local variables visible only within the scope of the View, and
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*Step4:* All of the bindings in the child Views are updated. Notice that in the case of `Foreach`
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the evaluation context for the `viewB0` and `viewB1` are `locals0` and `locals1` respectively.
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Locals allow the introduction of new local variables visible only within the scope of the View, and
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delegate any unknown references to the parent context.
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```
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@@ -151,17 +151,17 @@ delegate any unknown references to the parent context.
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</ul> | viewA
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```
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Each View can have zero or more ViewPorts. By inserting and removing child Views to and from the
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ViewContainers, the application can mutate the DOM structure to any desirable state. A View may contain
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individual nodes or a complex DOM structure. The insertion points for the child Views, known as
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ViewContainers, contain a DOM element which acts as an anchor. The anchor is either a `template` or
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a `script` element depending on your browser. It is used to identify where the child Views will be
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Each View can have zero or more ViewPorts. By inserting and removing child Views to and from the
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ViewContainers, the application can mutate the DOM structure to any desirable state. A View may contain
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individual nodes or a complex DOM structure. The insertion points for the child Views, known as
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ViewContainers, contain a DOM element which acts as an anchor. The anchor is either a `template` or
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a `script` element depending on your browser. It is used to identify where the child Views will be
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inserted.
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## Component Views
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A View can also contain Components. Components contain Shadow DOM for encapsulating their internal
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rendering state. Unlike ViewPorts which can contain zero or more Views, the Component always contains
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A View can also contain Components. Components contain Shadow DOM for encapsulating their internal
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rendering state. Unlike ViewPorts which can contain zero or more Views, the Component always contains
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exactly one Shadow View.
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```
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@@ -205,7 +205,7 @@ And assume the following HTML View:
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</div> | viewA(greeter)
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```
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The above UI is built using a single View, and hence a single context `greeter`. It can be expressed
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The above UI is built using a single View, and hence a single context `greeter`. It can be expressed
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in this pseudo-code.
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```
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@@ -215,15 +215,15 @@ var greeter = new Greeter();
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The View contains two bindings:
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1. `greeting`: This is bound to the `greeting` property on the `Greeter` instance.
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2. `name.value`: This poses a problem. There is no `name` property on the `Greeter` instance. To solve
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2. `name.value`: This poses a problem. There is no `name` property on the `Greeter` instance. To solve
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this we wrap the `Greeter` instance in the `Local` instance like so:
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```
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var greeter = new Locals(new Greeter(), {name: ref_to_input_element })
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```
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By wrapping the `Greeter` instance into the `Locals` we allow the view to introduce variables which
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are in addition to the `Greeter` instance. During the resolution of the expressions we first check
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By wrapping the `Greeter` instance into the `Locals` we allow the view to introduce variables which
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are in addition to the `Greeter` instance. During the resolution of the expressions we first check
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the locals, and then the `Greeter` instance.
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@@ -233,14 +233,14 @@ the locals, and then the `Greeter` instance.
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Views transition through a particular set of states:
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1. View is created from the ProtoView.
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2. View can be attached to an existing ViewContainer.
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3. Upon attaching View to the ViewContainer the View needs to be hydrated. The hydration process
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2. View can be attached to an existing ViewContainerRef.
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3. Upon attaching View to the ViewContainerRef the View needs to be hydrated. The hydration process
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involves instantiating all of the Directives associated with the current View.
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4. At this point the view is ready and renderable. Multiple changes can be delivered to the
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4. At this point the view is ready and renderable. Multiple changes can be delivered to the
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Directives from the ChangeDetection.
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5. At some point the View can be removed. At this point all of the directives are destroyed during
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5. At some point the View can be removed. At this point all of the directives are destroyed during
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the dehydration process and the view becomes inactive.
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6. The View has to wait until it is detached from the DOM. The delay in detaching could be caused
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6. The View has to wait until it is detached from the DOM. The delay in detaching could be caused
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because an animation is animating the view away.
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7. After the View is detached from the DOM it is ready to be reused. The view reuse allows the
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7. After the View is detached from the DOM it is ready to be reused. The view reuse allows the
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application to be faster in subsequent renderings.
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