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node_modules/lit-html/node/development/async-directive.js

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+import { isSingleExpression } from './directive-helpers.js';
+import { Directive, PartType } from './directive.js';
+export { Directive, PartType, directive } from './directive.js';
+
+/**
+ * @license
+ * Copyright 2017 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+/**
+ * Recursively walks down the tree of Parts/TemplateInstances/Directives to set
+ * the connected state of directives and run `disconnected`/ `reconnected`
+ * callbacks.
+ *
+ * @return True if there were children to disconnect; false otherwise
+ */
+const notifyChildrenConnectedChanged = (parent, isConnected) => {
+    var _a, _b;
+    const children = parent._$disconnectableChildren;
+    if (children === undefined) {
+        return false;
+    }
+    for (const obj of children) {
+        // The existence of `_$notifyDirectiveConnectionChanged` is used as a "brand" to
+        // disambiguate AsyncDirectives from other DisconnectableChildren
+        // (as opposed to using an instanceof check to know when to call it); the
+        // redundancy of "Directive" in the API name is to avoid conflicting with
+        // `_$notifyConnectionChanged`, which exists `ChildParts` which are also in
+        // this list
+        // Disconnect Directive (and any nested directives contained within)
+        // This property needs to remain unminified.
+        (_b = (_a = obj)['_$notifyDirectiveConnectionChanged']) === null || _b === void 0 ? void 0 : _b.call(_a, isConnected, false);
+        // Disconnect Part/TemplateInstance
+        notifyChildrenConnectedChanged(obj, isConnected);
+    }
+    return true;
+};
+/**
+ * Removes the given child from its parent list of disconnectable children, and
+ * if the parent list becomes empty as a result, removes the parent from its
+ * parent, and so forth up the tree when that causes subsequent parent lists to
+ * become empty.
+ */
+const removeDisconnectableFromParent = (obj) => {
+    let parent, children;
+    do {
+        if ((parent = obj._$parent) === undefined) {
+            break;
+        }
+        children = parent._$disconnectableChildren;
+        children.delete(obj);
+        obj = parent;
+    } while ((children === null || children === void 0 ? void 0 : children.size) === 0);
+};
+const addDisconnectableToParent = (obj) => {
+    // Climb the parent tree, creating a sparse tree of children needing
+    // disconnection
+    for (let parent; (parent = obj._$parent); obj = parent) {
+        let children = parent._$disconnectableChildren;
+        if (children === undefined) {
+            parent._$disconnectableChildren = children = new Set();
+        }
+        else if (children.has(obj)) {
+            // Once we've reached a parent that already contains this child, we
+            // can short-circuit
+            break;
+        }
+        children.add(obj);
+        installDisconnectAPI(parent);
+    }
+};
+/**
+ * Changes the parent reference of the ChildPart, and updates the sparse tree of
+ * Disconnectable children accordingly.
+ *
+ * Note, this method will be patched onto ChildPart instances and called from
+ * the core code when parts are moved between different parents.
+ */
+function reparentDisconnectables(newParent) {
+    if (this._$disconnectableChildren !== undefined) {
+        removeDisconnectableFromParent(this);
+        this._$parent = newParent;
+        addDisconnectableToParent(this);
+    }
+    else {
+        this._$parent = newParent;
+    }
+}
+/**
+ * Sets the connected state on any directives contained within the committed
+ * value of this part (i.e. within a TemplateInstance or iterable of
+ * ChildParts) and runs their `disconnected`/`reconnected`s, as well as within
+ * any directives stored on the ChildPart (when `valueOnly` is false).
+ *
+ * `isClearingValue` should be passed as `true` on a top-level part that is
+ * clearing itself, and not as a result of recursively disconnecting directives
+ * as part of a `clear` operation higher up the tree. This both ensures that any
+ * directive on this ChildPart that produced a value that caused the clear
+ * operation is not disconnected, and also serves as a performance optimization
+ * to avoid needless bookkeeping when a subtree is going away; when clearing a
+ * subtree, only the top-most part need to remove itself from the parent.
+ *
+ * `fromPartIndex` is passed only in the case of a partial `_clear` running as a
+ * result of truncating an iterable.
+ *
+ * Note, this method will be patched onto ChildPart instances and called from the
+ * core code when parts are cleared or the connection state is changed by the
+ * user.
+ */
+function notifyChildPartConnectedChanged(isConnected, isClearingValue = false, fromPartIndex = 0) {
+    const value = this._$committedValue;
+    const children = this._$disconnectableChildren;
+    if (children === undefined || children.size === 0) {
+        return;
+    }
+    if (isClearingValue) {
+        if (Array.isArray(value)) {
+            // Iterable case: Any ChildParts created by the iterable should be
+            // disconnected and removed from this ChildPart's disconnectable
+            // children (starting at `fromPartIndex` in the case of truncation)
+            for (let i = fromPartIndex; i < value.length; i++) {
+                notifyChildrenConnectedChanged(value[i], false);
+                removeDisconnectableFromParent(value[i]);
+            }
+        }
+        else if (value != null) {
+            // TemplateInstance case: If the value has disconnectable children (will
+            // only be in the case that it is a TemplateInstance), we disconnect it
+            // and remove it from this ChildPart's disconnectable children
+            notifyChildrenConnectedChanged(value, false);
+            removeDisconnectableFromParent(value);
+        }
+    }
+    else {
+        notifyChildrenConnectedChanged(this, isConnected);
+    }
+}
+/**
+ * Patches disconnection API onto ChildParts.
+ */
+const installDisconnectAPI = (obj) => {
+    var _a, _b;
+    var _c, _d;
+    if (obj.type == PartType.CHILD) {
+        (_a = (_c = obj)._$notifyConnectionChanged) !== null && _a !== void 0 ? _a : (_c._$notifyConnectionChanged = notifyChildPartConnectedChanged);
+        (_b = (_d = obj)._$reparentDisconnectables) !== null && _b !== void 0 ? _b : (_d._$reparentDisconnectables = reparentDisconnectables);
+    }
+};
+/**
+ * An abstract `Directive` base class whose `disconnected` method will be
+ * called when the part containing the directive is cleared as a result of
+ * re-rendering, or when the user calls `part.setConnected(false)` on
+ * a part that was previously rendered containing the directive (as happens
+ * when e.g. a LitElement disconnects from the DOM).
+ *
+ * If `part.setConnected(true)` is subsequently called on a
+ * containing part, the directive's `reconnected` method will be called prior
+ * to its next `update`/`render` callbacks. When implementing `disconnected`,
+ * `reconnected` should also be implemented to be compatible with reconnection.
+ *
+ * Note that updates may occur while the directive is disconnected. As such,
+ * directives should generally check the `this.isConnected` flag during
+ * render/update to determine whether it is safe to subscribe to resources
+ * that may prevent garbage collection.
+ */
+class AsyncDirective extends Directive {
+    constructor() {
+        super(...arguments);
+        // @internal
+        this._$disconnectableChildren = undefined;
+    }
+    /**
+     * Initialize the part with internal fields
+     * @param part
+     * @param parent
+     * @param attributeIndex
+     */
+    _$initialize(part, parent, attributeIndex) {
+        super._$initialize(part, parent, attributeIndex);
+        addDisconnectableToParent(this);
+        this.isConnected = part._$isConnected;
+    }
+    // This property needs to remain unminified.
+    /**
+     * Called from the core code when a directive is going away from a part (in
+     * which case `shouldRemoveFromParent` should be true), and from the
+     * `setChildrenConnected` helper function when recursively changing the
+     * connection state of a tree (in which case `shouldRemoveFromParent` should
+     * be false).
+     *
+     * @param isConnected
+     * @param isClearingDirective - True when the directive itself is being
+     *     removed; false when the tree is being disconnected
+     * @internal
+     */
+    ['_$notifyDirectiveConnectionChanged'](isConnected, isClearingDirective = true) {
+        var _a, _b;
+        if (isConnected !== this.isConnected) {
+            this.isConnected = isConnected;
+            if (isConnected) {
+                (_a = this.reconnected) === null || _a === void 0 ? void 0 : _a.call(this);
+            }
+            else {
+                (_b = this.disconnected) === null || _b === void 0 ? void 0 : _b.call(this);
+            }
+        }
+        if (isClearingDirective) {
+            notifyChildrenConnectedChanged(this, isConnected);
+            removeDisconnectableFromParent(this);
+        }
+    }
+    /**
+     * Sets the value of the directive's Part outside the normal `update`/`render`
+     * lifecycle of a directive.
+     *
+     * This method should not be called synchronously from a directive's `update`
+     * or `render`.
+     *
+     * @param directive The directive to update
+     * @param value The value to set
+     */
+    setValue(value) {
+        if (isSingleExpression(this.__part)) {
+            this.__part._$setValue(value, this);
+        }
+        else {
+            // this.__attributeIndex will be defined in this case, but
+            // assert it in dev mode
+            if (this.__attributeIndex === undefined) {
+                throw new Error(`Expected this.__attributeIndex to be a number`);
+            }
+            const newValues = [...this.__part._$committedValue];
+            newValues[this.__attributeIndex] = value;
+            this.__part._$setValue(newValues, this, 0);
+        }
+    }
+    /**
+     * User callbacks for implementing logic to release any resources/subscriptions
+     * that may have been retained by this directive. Since directives may also be
+     * re-connected, `reconnected` should also be implemented to restore the
+     * working state of the directive prior to the next render.
+     */
+    disconnected() { }
+    reconnected() { }
+}
+
+export { AsyncDirective };
+//# sourceMappingURL=async-directive.js.map