/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import { Optional, SkipSelf } from '../../di';
import { ListWrapper } from '../../facade/collection';
import { isBlank, isPresent } from '../../facade/lang';
/**
 * A repository of different Map diffing strategies used by NgClass, NgStyle, and others.
 * @stable
 */
export var KeyValueDiffers = (function () {
    function KeyValueDiffers(factories) {
        this.factories = factories;
    }
    KeyValueDiffers.create = function (factories, parent) {
        if (isPresent(parent)) {
            var copied = ListWrapper.clone(parent.factories);
            factories = factories.concat(copied);
            return new KeyValueDiffers(factories);
        }
        else {
            return new KeyValueDiffers(factories);
        }
    };
    /**
     * Takes an array of {@link KeyValueDifferFactory} and returns a provider used to extend the
     * inherited {@link KeyValueDiffers} instance with the provided factories and return a new
     * {@link KeyValueDiffers} instance.
     *
     * The following example shows how to extend an existing list of factories,
           * which will only be applied to the injector for this component and its children.
           * This step is all that's required to make a new {@link KeyValueDiffer} available.
     *
     * ### Example
     *
     * ```
     * @Component({
     *   viewProviders: [
     *     KeyValueDiffers.extend([new ImmutableMapDiffer()])
     *   ]
     * })
     * ```
     */
    KeyValueDiffers.extend = function (factories) {
        return {
            provide: KeyValueDiffers,
            useFactory: function (parent) {
                if (isBlank(parent)) {
                    // Typically would occur when calling KeyValueDiffers.extend inside of dependencies passed
                    // to
                    // bootstrap(), which would override default pipes instead of extending them.
                    throw new Error('Cannot extend KeyValueDiffers without a parent injector');
                }
                return KeyValueDiffers.create(factories, parent);
            },
            // Dependency technically isn't optional, but we can provide a better error message this way.
            deps: [[KeyValueDiffers, new SkipSelf(), new Optional()]]
        };
    };
    KeyValueDiffers.prototype.find = function (kv) {
        var factory = this.factories.find(function (f) { return f.supports(kv); });
        if (isPresent(factory)) {
            return factory;
        }
        else {
            throw new Error("Cannot find a differ supporting object '" + kv + "'");
        }
    };
    return KeyValueDiffers;
}());
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