儲存區域的資訊清單

有別於 local 和 sync 儲存空間區域，managed 儲存空間區域的結構必須 宣告為 JSON 結構定義，且經過 Chrome 嚴格驗證。這個結構定義必須儲存在 檔案 (由 "storage" 資訊清單鍵的 "managed_schema" 屬性表示)，並宣告 擴充功能支援的企業政策。

政策類似選項，但是由系統管理員 (而非使用者) 設定 允許為機構中的所有使用者預先設定擴充功能。瞭解 Chrome 如何處理 政策。

宣告政策後，即可從 storage.managed API 讀取政策。取決於 強制執行管理員設定的政策。

manifest.json 範例

storage.managed_schema 屬性代表副檔名中含有政策的檔案 結構定義。

{
  "name": "My enterprise extension",
  "storage": {
    "managed_schema": "schema.json"
  },
  ...
}

Chrome 接著會從基礎作業系統和 Google Apps 載入這些政策 。偵測到政策變更時，就會觸發 storage.onChanged 事件。 包括在擴充功能使用事件頁面時，瀏覽器並未執行時顯示。您可以進行驗證 Chrome 在 chrome://policy 中所載入的政策

結構定義格式

JSON 結構定義格式還有 Chrome 額外規定：

  • 頂層結構定義必須採用 object 類型。
  • 頂層 object 不得包含 additionalProperties。宣告的 properties 是 政策。
  • 每個結構定義都必須有一個 $ref 值或僅有一個 type。

如果結構定義無效，Chrome 就不會載入擴充功能，且會說明 未驗證結構定義如果政策值不符合結構定義，就不會 storage.managed API 所發布。

結構定義範例

{
  "type": "object",

  // "properties" maps an optional key of this object to its schema. At the
  // top-level object, these keys are the policy names supported.
  "properties": {

    // The policy name "AutoSave" is mapped to its schema, which in this case
    // declares it as a simple boolean value.
    // "title" and "description" are optional and are used to show a
    // user-friendly name and documentation to the administrator.
    "AutoSave": {
      "title": "Automatically save changes.",
      "description": "If set to true then changes will be automatically saved.",
      "type": "boolean"
    },

    // Other simple types supported include "integer", "string" and "number".
    "PollRefreshRate": {
      "type": "integer"
    },

    "DefaultServiceUrl": {
      "type": "string"
    },

    // "array" is a list of items that conform to another schema, described
    // in "items". An example to this schema is [ "one", "two" ].
    "ServiceUrls": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },

    // A more complex example that describes a list of bookmarks. Each bookmark
    // has a "title", and can have a "url" or a list of "children" bookmarks.
    // The "id" attribute is used to name a schema, and other schemas can reuse
    // it using the "$ref" attribute.
    "Bookmarks": {
      "type": "array",
      "id": "ListOfBookmarks",
      "items": {
        "type": "object",
        "properties": {
          "title": { "type": "string" },
          "url": { "type": "string" },
          "children": { "$ref": "ListOfBookmarks" }
        }
      }
    },

    // An "object" can have known properties listed as "properties", and can
    // optionally have "additionalProperties" indicating a schema to apply to
    // keys that aren't found in "properties".
    // This example policy could map a URL to its settings. An example value:
    // {
    //   "youtube.com": {
    //     "blocklisted": true
    //   },
    //   "google.com": {
    //     "bypass_proxy": true
    //   }
    // }
    "SettingsForUrls": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "blocklisted": { "type": "boolean" },
          "bypass_proxy": { "type": "boolean" }
        }
      }
    }
  }
}