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| 1 | +import { validateArgCount, validateCallback } from '../../utils/validation'; |
| 2 | +import { validatePathString } from '../core/util/validation'; |
| 3 | +import { Path } from '../core/util/Path'; |
| 4 | +import { PRIORITY_INDEX } from '../core/snap/indexes/PriorityIndex'; |
| 5 | +import { Node } from '../core/snap/Node'; |
| 6 | +import { Reference } from './Reference'; |
| 7 | +import { Index } from '../core/snap/indexes/Index'; |
| 8 | +import { ChildrenNode } from '../core/snap/ChildrenNode'; |
| 9 | + |
| 10 | +/** |
| 11 | + * Class representing a firebase data snapshot. It wraps a SnapshotNode and |
| 12 | + * surfaces the public methods (val, forEach, etc.) we want to expose. |
| 13 | + */ |
| 14 | +export class DataSnapshot { |
| 15 | + /** |
| 16 | + * @param {!Node} node_ A SnapshotNode to wrap. |
| 17 | + * @param {!Reference} ref_ The ref of the location this snapshot came from. |
| 18 | + * @param {!Index} index_ The iteration order for this snapshot |
| 19 | + */ |
| 20 | + constructor(private readonly node_: Node, |
| 21 | + private readonly ref_: Reference, |
| 22 | + private readonly index_: Index) { |
| 23 | + } |
| 24 | + |
| 25 | + /** |
| 26 | + * Retrieves the snapshot contents as JSON. Returns null if the snapshot is |
| 27 | + * empty. |
| 28 | + * |
| 29 | + * @return {*} JSON representation of the DataSnapshot contents, or null if empty. |
| 30 | + */ |
| 31 | + val(): any { |
| 32 | + validateArgCount('DataSnapshot.val', 0, 0, arguments.length); |
| 33 | + return this.node_.val(); |
| 34 | + } |
| 35 | + |
| 36 | + /** |
| 37 | + * Returns the snapshot contents as JSON, including priorities of node. Suitable for exporting |
| 38 | + * the entire node contents. |
| 39 | + * @return {*} JSON representation of the DataSnapshot contents, or null if empty. |
| 40 | + */ |
| 41 | + exportVal(): any { |
| 42 | + validateArgCount('DataSnapshot.exportVal', 0, 0, arguments.length); |
| 43 | + return this.node_.val(true); |
| 44 | + } |
| 45 | + |
| 46 | + // Do not create public documentation. This is intended to make JSON serialization work but is otherwise unnecessary |
| 47 | + // for end-users |
| 48 | + toJSON(): any { |
| 49 | + // Optional spacer argument is unnecessary because we're depending on recursion rather than stringifying the content |
| 50 | + validateArgCount('DataSnapshot.toJSON', 0, 1, arguments.length); |
| 51 | + return this.exportVal(); |
| 52 | + } |
| 53 | + |
| 54 | + /** |
| 55 | + * Returns whether the snapshot contains a non-null value. |
| 56 | + * |
| 57 | + * @return {boolean} Whether the snapshot contains a non-null value, or is empty. |
| 58 | + */ |
| 59 | + exists(): boolean { |
| 60 | + validateArgCount('DataSnapshot.exists', 0, 0, arguments.length); |
| 61 | + return !this.node_.isEmpty(); |
| 62 | + } |
| 63 | + |
| 64 | + /** |
| 65 | + * Returns a DataSnapshot of the specified child node's contents. |
| 66 | + * |
| 67 | + * @param {!string} childPathString Path to a child. |
| 68 | + * @return {!DataSnapshot} DataSnapshot for child node. |
| 69 | + */ |
| 70 | + child(childPathString: string): DataSnapshot { |
| 71 | + validateArgCount('DataSnapshot.child', 0, 1, arguments.length); |
| 72 | + // Ensure the childPath is a string (can be a number) |
| 73 | + childPathString = String(childPathString); |
| 74 | + validatePathString('DataSnapshot.child', 1, childPathString, false); |
| 75 | + |
| 76 | + const childPath = new Path(childPathString); |
| 77 | + const childRef = this.ref_.child(childPath); |
| 78 | + return new DataSnapshot(this.node_.getChild(childPath), childRef, PRIORITY_INDEX); |
| 79 | + } |
| 80 | + |
| 81 | + /** |
| 82 | + * Returns whether the snapshot contains a child at the specified path. |
| 83 | + * |
| 84 | + * @param {!string} childPathString Path to a child. |
| 85 | + * @return {boolean} Whether the child exists. |
| 86 | + */ |
| 87 | + hasChild(childPathString: string): boolean { |
| 88 | + validateArgCount('DataSnapshot.hasChild', 1, 1, arguments.length); |
| 89 | + validatePathString('DataSnapshot.hasChild', 1, childPathString, false); |
| 90 | + |
| 91 | + const childPath = new Path(childPathString); |
| 92 | + return !this.node_.getChild(childPath).isEmpty(); |
| 93 | + } |
| 94 | + |
| 95 | + /** |
| 96 | + * Returns the priority of the object, or null if no priority was set. |
| 97 | + * |
| 98 | + * @return {string|number|null} The priority. |
| 99 | + */ |
| 100 | + getPriority(): string | number | null { |
| 101 | + validateArgCount('DataSnapshot.getPriority', 0, 0, arguments.length); |
| 102 | + |
| 103 | + // typecast here because we never return deferred values or internal priorities (MAX_PRIORITY) |
| 104 | + return /**@type {string|number|null} */ <string | number | null>(this.node_.getPriority().val()); |
| 105 | + } |
| 106 | + |
| 107 | + /** |
| 108 | + * Iterates through child nodes and calls the specified action for each one. |
| 109 | + * |
| 110 | + * @param {function(!DataSnapshot)} action Callback function to be called |
| 111 | + * for each child. |
| 112 | + * @return {boolean} True if forEach was canceled by action returning true for |
| 113 | + * one of the child nodes. |
| 114 | + */ |
| 115 | + forEach(action: (d: DataSnapshot) => any): boolean { |
| 116 | + validateArgCount('DataSnapshot.forEach', 1, 1, arguments.length); |
| 117 | + validateCallback('DataSnapshot.forEach', 1, action, false); |
| 118 | + |
| 119 | + if (this.node_.isLeafNode()) |
| 120 | + return false; |
| 121 | + |
| 122 | + const childrenNode = /**@type {ChildrenNode} */ <ChildrenNode>(this.node_); |
| 123 | + // Sanitize the return value to a boolean. ChildrenNode.forEachChild has a weird return type... |
| 124 | + return !!childrenNode.forEachChild(this.index_, (key, node) => { |
| 125 | + return action(new DataSnapshot(node, this.ref_.child(key), PRIORITY_INDEX)); |
| 126 | + }); |
| 127 | + } |
| 128 | + |
| 129 | + /** |
| 130 | + * Returns whether this DataSnapshot has children. |
| 131 | + * @return {boolean} True if the DataSnapshot contains 1 or more child nodes. |
| 132 | + */ |
| 133 | + hasChildren(): boolean { |
| 134 | + validateArgCount('DataSnapshot.hasChildren', 0, 0, arguments.length); |
| 135 | + |
| 136 | + if (this.node_.isLeafNode()) |
| 137 | + return false; |
| 138 | + else |
| 139 | + return !this.node_.isEmpty(); |
| 140 | + } |
| 141 | + |
| 142 | + get key() { |
| 143 | + return this.ref_.getKey(); |
| 144 | + } |
| 145 | + |
| 146 | + /** |
| 147 | + * Returns the number of children for this DataSnapshot. |
| 148 | + * @return {number} The number of children that this DataSnapshot contains. |
| 149 | + */ |
| 150 | + numChildren(): number { |
| 151 | + validateArgCount('DataSnapshot.numChildren', 0, 0, arguments.length); |
| 152 | + |
| 153 | + return this.node_.numChildren(); |
| 154 | + } |
| 155 | + |
| 156 | + /** |
| 157 | + * @return {Reference} The Firebase reference for the location this snapshot's data came from. |
| 158 | + */ |
| 159 | + getRef(): Reference { |
| 160 | + validateArgCount('DataSnapshot.ref', 0, 0, arguments.length); |
| 161 | + |
| 162 | + return this.ref_; |
| 163 | + } |
| 164 | + |
| 165 | + get ref() { |
| 166 | + return this.getRef(); |
| 167 | + } |
| 168 | +} |
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