| Index: third_party/pkg/di/lib/injector.dart
|
| diff --git a/third_party/pkg/di/lib/injector.dart b/third_party/pkg/di/lib/injector.dart
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..343a66edba43dd3c5a1f51eeae8f1aaafd5750d2
|
| --- /dev/null
|
| +++ b/third_party/pkg/di/lib/injector.dart
|
| @@ -0,0 +1,219 @@
|
| +part of di;
|
| +
|
| +class Injector {
|
| +
|
| + /**
|
| + * Name of the injector or null of none is given.
|
| + */
|
| + final String name;
|
| +
|
| + static const List<Type> _PRIMITIVE_TYPES = const <Type>[
|
| + num, int, double, String, bool
|
| + ];
|
| +
|
| + /**
|
| + * Returns the parent injector or null if root.
|
| + */
|
| + final Injector parent;
|
| +
|
| + Injector _root;
|
| +
|
| + Map<Type, _Provider> _providers = <Type, _Provider>{};
|
| +
|
| + final Map<Type, Object> instances = <Type, Object>{};
|
| +
|
| + final List<Type> resolving = <Type>[];
|
| +
|
| + final bool allowImplicitInjection;
|
| +
|
| + Iterable<Type> _typesCache;
|
| +
|
| + /**
|
| + * List of all types which the injector can return
|
| + */
|
| + Iterable<Type> get _types {
|
| + if (_typesCache == null) {
|
| + _typesCache = _providers.keys;
|
| + }
|
| + return _typesCache;
|
| + }
|
| +
|
| + Injector({List<Module> modules, String name,
|
| + bool allowImplicitInjection: false})
|
| + : this.fromParent(modules, null,
|
| + name: name, allowImplicitInjection: allowImplicitInjection);
|
| +
|
| + Injector.fromParent(List<Module> modules,
|
| + Injector this.parent, {this.name, this.allowImplicitInjection}) {
|
| + _root = parent == null ? this : parent._root;
|
| + if (modules != null) {
|
| + modules.forEach((module) {
|
| + _providers.addAll(module._bindings);
|
| + });
|
| + }
|
| + _providers[Injector] = new _ValueProvider(this);
|
| + }
|
| +
|
| + Injector get root => _root;
|
| +
|
| + Set<Type> get types {
|
| + var types = new Set.from(_types);
|
| + var parent = this.parent;
|
| + while (parent != null) {
|
| + types.addAll(parent._types);
|
| + parent = parent.parent;
|
| + }
|
| + return types;
|
| + }
|
| +
|
| + String _error(message, [appendDependency]) {
|
| + if (appendDependency != null) {
|
| + resolving.add(appendDependency);
|
| + }
|
| +
|
| + String graph = resolving.join(' -> ');
|
| +
|
| + resolving.clear();
|
| +
|
| + return '$message (resolving $graph)';
|
| + }
|
| +
|
| + dynamic _getInstanceByType(Type typeName, Injector requester) {
|
| + _checkTypeConditions(typeName);
|
| +
|
| + if (resolving.contains(typeName)) {
|
| + throw new CircularDependencyError(
|
| + _error('Cannot resolve a circular dependency!', typeName));
|
| + }
|
| +
|
| + var providerWithInjector = _getProviderWithInjectorForType(typeName);
|
| + var provider = providerWithInjector.provider;
|
| + var injector = providerWithInjector.injector;
|
| + var visible = provider.visibility != null ?
|
| + provider.visibility(requester, injector) :
|
| + _defaultVisibility(requester, injector);
|
| +
|
| + if (visible && instances.containsKey(typeName)) {
|
| + return instances[typeName];
|
| + }
|
| +
|
| + if (providerWithInjector.injector != this || !visible) {
|
| + if (!visible) {
|
| + if (injector.parent == null) {
|
| + throw new NoProviderError(
|
| + _error('No provider found for ${typeName}!', typeName));
|
| + }
|
| + injector =
|
| + injector.parent._getProviderWithInjectorForType(typeName).injector;
|
| + }
|
| + return injector._getInstanceByType(typeName, requester);
|
| + }
|
| +
|
| + var value;
|
| + try {
|
| + var strategy = provider.creationStrategy != null ?
|
| + provider.creationStrategy : _defaultCreationStrategy;
|
| + value = strategy(requester, injector, () {
|
| + resolving.add(typeName);
|
| + var val = provider.get(this, requester, _getInstanceByType, _error);
|
| + resolving.removeLast();
|
| + return val;
|
| + });
|
| + } catch(e) {
|
| + resolving.clear();
|
| + rethrow;
|
| + }
|
| +
|
| + // cache the value.
|
| + providerWithInjector.injector.instances[typeName] = value;
|
| + return value;
|
| + }
|
| +
|
| + /// Returns a pair for provider and the injector where it's defined.
|
| + _ProviderWithDefiningInjector _getProviderWithInjectorForType(Type typeName) {
|
| + if (_providers.containsKey(typeName)) {
|
| + return new _ProviderWithDefiningInjector(_providers[typeName], this);
|
| + }
|
| +
|
| + if (parent != null) {
|
| + return parent._getProviderWithInjectorForType(typeName);
|
| + }
|
| +
|
| + if (allowImplicitInjection) {
|
| + return new _ProviderWithDefiningInjector(
|
| + new _TypeProvider(typeName), this);
|
| + }
|
| +
|
| + throw new NoProviderError(_error('No provider found for '
|
| + '${typeName}!', typeName));
|
| + }
|
| +
|
| + void _checkTypeConditions(Type typeName) {
|
| + if (_PRIMITIVE_TYPES.contains(typeName)) {
|
| + throw new NoProviderError(_error('Cannot inject a primitive type '
|
| + 'of $typeName!', typeName));
|
| + }
|
| + }
|
| +
|
| +
|
| + // PUBLIC API
|
| +
|
| + /**
|
| + * Get an instance for given token ([Type]).
|
| + *
|
| + * If the injector already has an instance for this token, it returns this
|
| + * instance. Otherwise, injector resolves all its dependencies, instantiate
|
| + * new instance and returns this instance.
|
| + *
|
| + * If there is no binding for given token, injector asks parent injector.
|
| + *
|
| + * If there is no parent injector, an implicit binding is used. That is,
|
| + * the token ([Type]) is instantiated.
|
| + */
|
| + dynamic get(Type type) => _getInstanceByType(type, this);
|
| +
|
| + /**
|
| + * Create a child injector.
|
| + *
|
| + * Child injector can override any bindings by adding additional modules.
|
| + *
|
| + * It also accepts a list of tokens that a new instance should be forced.
|
| + * That means, even if some parent injector already has an instance for this
|
| + * token, there will be a new instance created in the child injector.
|
| + */
|
| + Injector createChild(List<Module> modules,
|
| + {List<Type> forceNewInstances, String name}) {
|
| + if (forceNewInstances != null) {
|
| + Module forceNew = new Module();
|
| + forceNewInstances.forEach((type) {
|
| + var providerWithInjector = _getProviderWithInjectorForType(type);
|
| + var provider = providerWithInjector.provider;
|
| + forceNew.factory(type,
|
| + (Injector inj) => provider.get(this, inj, inj._getInstanceByType,
|
| + inj._error),
|
| + creation: provider.creationStrategy,
|
| + visibility: provider.visibility);
|
| + });
|
| +
|
| + modules = modules.toList(); // clone
|
| + modules.add(forceNew);
|
| + }
|
| +
|
| + return newFromParent(modules, name);
|
| + }
|
| +
|
| + newFromParent(List<Module> modules, String name) {
|
| + throw new UnimplementedError('This method must be overriden.');
|
| + }
|
| +
|
| + Object newInstanceOf(Type type, ObjectFactory factory, Injector requestor,
|
| + errorHandler(message, [appendDependency])) {
|
| + throw new UnimplementedError('This method must be overriden.');
|
| + }
|
| +}
|
| +
|
| +class _ProviderWithDefiningInjector {
|
| + final _Provider provider;
|
| + final Injector injector;
|
| + _ProviderWithDefiningInjector(this.provider, this.injector);
|
| +}
|
|
|