问题
I would like to dynamically build a component tree basing on some information received from AJAX calls.
How to programmatically add a component to the DOM from inside of other component? I have <outer-comp> and I would like, basing on some logic, insert an <inner-comp>. The following code just inserts the elements <inner-comp></inner-comp> to the DOM, and not actual <inner-comp> representation.
@NgComponent(
selector: \'outer-comp\',
templateUrl: \'view/outer_component.html\',
cssUrl: \'view/outer_component.css\',
publishAs: \'outer\'
)
class AppComponent extends NgShadowRootAware {
void onShadowRoot(ShadowRoot shadowRoot) {
DivElement inner = shadowRoot.querySelector(\"#inner\");
inner.appendHtml(\"<inner-comp></inner-comp>\");
}
}
Update: I managed to render the inner component correctly in the following way, but I\'m still not sure if this is the proper way:
class AppComponent extends NgShadowRootAware {
Compiler compiler;
Injector injector;
AppComponent(this.compiler, this.injector);
void onShadowRoot(ShadowRoot shadowRoot) {
DivElement inner = shadowRoot.querySelector(\"#inner\");
inner.appendHtml(\"<inner-comp></inner-comp>\");
BlockFactory template = compiler(inner.nodes);
var block = template(injector);
inner.replaceWith(block.elements[0]);
}
}
回答1:
This would be a proper use of the block API.
class AppComponent extends NgShadowRootAware {
Compiler compiler;
Injector injector;
Scope scope;
DirectiveMap directives;
AppComponent(this.compiler, this.injector, this.scope, this.directives);
void onShadowRoot(ShadowRoot shadowRoot) {
DivElement inner = shadowRoot.querySelector("#inner");
inner.appendHtml("<inner-comp></inner-comp>");
BlockFactory template = compiler([inner], directives);
Scope childScope = scope.$new();
Injector childInjector =
injector.createChild(new Module()..value(Scope, childScope));
template(childInjector, [inner]);
}
}
Also, if you ever need to recompile the inner template make sure you do childScope.$destroy() on the previous childScope.
回答2:
The API has changed in AngularDart 0.9.9:
- BlockFactory now is ViewFactory
- scope.$new now seems to be scope.createChild(scope.context)
- injector.createChild(modules) now requires a list of modules (instead of a single one)
AngularDart 0.10.0 introduces these changes:
- NgShadowRootAware not is ShadowRootAware
- ..value() now is ..bind(., toValue: .)
So the code of pavelgj now looks like so:
class AppComponent extends ShadowRootAware {
Compiler compiler;
Injector injector;
Scope scope;
DirectiveMap directives;
AppComponent(this.compiler, this.injector, this.scope, this.directives);
void onShadowRoot(ShadowRoot shadowRoot) {
DivElement inner = shadowRoot.querySelector("#inner");
inner.appendHtml("<inner-comp></inner-comp>");
ViewFactory template = compiler([inner], directives);
Scope childScope = scope.createChild(scope.context);
Injector childInjector =
injector.createChild([new Module()..bind(Scope, toValue: childScope)]);
template(childInjector, [inner]);
}
}
回答3:
The above code samples on longer work because of changes in the Angular Dart library. Specifically ViewFactory.call which no longer takes an injector but takes a Scope and a DirectiveInjector. I've tried adapting what's above and I get very close. The component shows up but none of the bindings are replaced (I see {{cmp.value}} for example.
Here's the code I'm using. I think the issue here is that DirectiveInjector is coming in as null.
void main() {
IBMModule module = new IBMModule();
AngularModule angularModule = new AngularModule();
Injector injector = applicationFactory()
.addModule(module)
.run();
AppComponent appComponent = injector.get(AppComponent);
appComponent.addElement("<brazos-input-string label='test'/>");
}
@Injectable()
class AppComponent {
NodeValidator validator;
Compiler _compiler;
DirectiveInjector _injector;
DirectiveMap _directiveMap;
NodeTreeSanitizer _nodeTreeSanitizer;
Scope _scope;
AppComponent(this._injector, this._compiler, this._directiveMap, this._scope, this._nodeTreeSanitizer) {
validator = new NodeValidatorBuilder.common()
..allowCustomElement("BRAZOS-INPUT-STRING")
..allowHtml5()
..allowTemplating();
}
void addElement(String elementHTML) {
DivElement container = querySelector("#container");
DivElement inner = new DivElement();
inner.setInnerHtml(elementHTML, validator: validator);
ViewFactory viewFactory = _compiler.call([inner], _directiveMap);
Scope childScope = _scope.createChild(new PrototypeMap(_scope.context));
if (_injector == null) {
print("injector is null");
}
View newView = viewFactory.call(childScope, _injector);
container.append(inner);
newView.nodes.forEach((node) => inner.append(node));
}
}
class IBMModule extends Module {
IBMModule() {
bind(BrazosInputStringComponent);
bind(BrazosTextAreaComponent);
bind(BrazosButtonComponent);
bind(ProcessDataProvider, toImplementation: ActivitiDataProvider);
bind(AppComponent);
}
}
回答4:
I did finally get this to work but was not happy with having to add a timer:
@Injectable()
class AppComponent{
NodeValidator validator;
Compiler _compiler;
DirectiveInjector _directiveInjector;
DirectiveMap _directiveMap;
NodeTreeSanitizer _nodeTreeSanitizer;
Injector _appInjector;
Scope _scope;
AppComponent(this._directiveInjector, this._compiler, this._directiveMap, this._nodeTreeSanitizer, this._appInjector, this._scope) {
validator = new MyValidator();
}
void addElement(String id, String elementHTML) {
DivElement container = querySelector(id);
DivElement inner = new DivElement();
container.append(inner);
Element element = new Element.html(elementHTML, validator: validator);
ViewFactory viewFactory = _compiler.call([element], _directiveMap);
if (_scope != null) {
Scope childScope = _scope.createProtoChild();
View newView = viewFactory.call(childScope, _directiveInjector);
newView.nodes.forEach((node) => inner.append(node));
Timer.run(() => childScope.apply());
} else {
print("scope is null");
}
}
}
回答5:
EDIT
The package http://pub.dartlang.org/packages/bwu_angular contains this decorator/directive as bwu-safe-html
------
I use a custom directive for that
@NgDirective(
selector: '[my-bind-html]'
)
class MyBindHtmlDirective {
static dom.NodeValidator validator;
dom.Element _element;
Compiler _compiler;
Injector _injector;
DirectiveMap _directiveMap;
MyBindHtmlDirective(this._element, this._injector, this._compiler, this._directiveMap) {
validator = new dom.NodeValidatorBuilder.common()
..allowHtml5()
..allowImages();
}
@NgOneWay('my-bind-html')
set value(value) {
if(value == null) {
_element.nodes.clear();
return;
}
_element.setInnerHtml((value == null ? '' : value.toString()),
validator: validator);
if(value != null) {
_compiler(_element.childNodes, _directiveMap)(_injector, _element.childNodes);
}
}
}
It can be used like
my-bind-html='ctrl.somehtml'
Angular issue
I created an issue to include this functionality into Angulars ng-bind-html https://github.com/angular/angular.dart/issues/742 (declined)
来源：https://stackoverflow.com/questions/20423565/how-to-add-a-component-programmatically-in-angular-dart