儲存區域的資訊清單

localsync 儲存區不同,managed 儲存區需要將其結構宣告為 JSON 結構定義,並由 Chrome 嚴格驗證。這個結構定義必須儲存在 "storage" 資訊清單鍵的 "managed_schema" 屬性所指示的檔案中,並宣告擴充功能支援的企業政策。

政策與選項類似,但由系統管理員而非使用者設定,可讓擴充功能預先設定給機構的所有使用者。瞭解 Chrome 如何處理 政策

宣告政策後,即可透過 storage.managed API 讀取這些政策。擴充功能會負責強制執行管理員設定的政策。

manifest.json 範例

storage.managed_schema 屬性會指出擴充功能中含有政策結構定義的檔案。

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

接著,Chrome 會從基礎作業系統和已登入使用者的 Google 應用程式載入這些政策。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 結構定義格式有幾項額外的要求:

  • 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 是這項擴充功能的政策。
  • 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,並會指出未驗證結構定義的原因。如果政策值不符合結構定義,就不會由 storage.managed API 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" }
       
}
     
}
   
}
 
}
}