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types/YMap.js

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+/**
+ * @module types
+ */
+
+import { Item } from '../structs/Item.js'
+import { Type } from '../structs/Type.js'
+import { ItemJSON } from '../structs/ItemJSON.js'
+import { logItemHelper } from '../protocols/syncProtocol.js'
+import { YEvent } from '../utils/YEvent.js'
+
+/**
+ * Event that describes the changes on a YMap.
+ */
+export class YMapEvent extends YEvent {
+  /**
+   * @param {YMap} ymap The YArray that changed.
+   * @param {Set<any>} subs The keys that changed.
+   * @param {boolean} remote Whether the change was created by a remote peer.
+   */
+  constructor (ymap, subs, remote) {
+    super(ymap)
+    this.keysChanged = subs
+    this.remote = remote
+  }
+}
+
+/**
+ * A shared Map implementation.
+ */
+export class YMap extends Type {
+  /**
+   * Creates YMap Event and calls observers.
+   *
+   * @private
+   */
+  _callObserver (transaction, parentSubs, remote) {
+    this._callEventHandler(transaction, new YMapEvent(this, parentSubs, remote))
+  }
+
+  /**
+   * Transforms this Shared Type to a JSON object.
+   *
+   * @return {Object}
+   */
+  toJSON () {
+    const map = {}
+    for (let [key, item] of this._map) {
+      if (!item._deleted) {
+        let res
+        if (item instanceof Type) {
+          if (item.toJSON !== undefined) {
+            res = item.toJSON()
+          } else {
+            res = item.toString()
+          }
+        } else {
+          res = item._content[0]
+        }
+        map[key] = res
+      }
+    }
+    return map
+  }
+
+  /**
+   * Returns the keys for each element in the YMap Type.
+   *
+   * @return {Array}
+   */
+  keys () {
+    // TODO: Should return either Iterator or Set!
+    let keys = []
+    for (let [key, value] of this._map) {
+      if (!value._deleted) {
+        keys.push(key)
+      }
+    }
+    return keys
+  }
+
+  /**
+   * Remove a specified element from this YMap.
+   *
+   * @param {string} key The key of the element to remove.
+   */
+  delete (key) {
+    this._transact((y) => {
+      let c = this._map.get(key)
+      if (y !== null && c !== undefined) {
+        c._delete(y)
+      }
+    })
+  }
+
+  /**
+   * Adds or updates an element with a specified key and value.
+   *
+   * @param {string} key The key of the element to add to this YMap
+   * @param {Object | string | number | Type} value The value of the element to add
+   */
+  set (key, value) {
+    this._transact(y => {
+      const old = this._map.get(key) || null
+      if (old !== null) {
+        if (
+          old.constructor === ItemJSON &&
+          !old._deleted && old._content[0] === value
+        ) {
+          // Trying to overwrite with same value
+          // break here
+          return value
+        }
+        if (y !== null) {
+          old._delete(y)
+        }
+      }
+      let v
+      if (typeof value === 'function') {
+        v = new value() // eslint-disable-line new-cap
+        value = v
+      } else if (value instanceof Item) {
+        v = value
+      } else {
+        v = new ItemJSON()
+        v._content = [value]
+      }
+      v._right = old
+      v._right_origin = old
+      v._parent = this
+      v._parentSub = key
+      if (y !== null) {
+        v._integrate(y)
+      } else {
+        this._map.set(key, v)
+      }
+    })
+    return value
+  }
+
+  /**
+   * Returns a specified element from this YMap.
+   *
+   * @param {string} key The key of the element to return.
+   */
+  get (key) {
+    let v = this._map.get(key)
+    if (v === undefined || v._deleted) {
+      return undefined
+    }
+    if (v instanceof Type) {
+      return v
+    } else {
+      return v._content[v._content.length - 1]
+    }
+  }
+
+  /**
+   * Returns a boolean indicating whether the specified key exists or not.
+   *
+   * @param {string} key The key to test.
+   */
+  has (key) {
+    let v = this._map.get(key)
+    if (v === undefined || v._deleted) {
+      return false
+    } else {
+      return true
+    }
+  }
+
+  /**
+   * Transform this YXml Type to a readable format.
+   * Useful for logging as all Items and Delete implement this method.
+   *
+   * @private
+   */
+  _logString () {
+    return logItemHelper('YMap', this, `mapSize:${this._map.size}`)
+  }
+}