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,並由 Chrome 嚴格驗證。這個結構定義必須儲存在 "storage"
資訊清單金鑰的 "managed_schema"
屬性指定的檔案中,並宣告擴充功能支援的企業政策。
政策很像選項,但是由系統管理員設定用於安裝政策的擴充功能,允許機構的所有使用者預先設定擴充功能。如需 Chrome 本身的政策範例,請參閱 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。這個擴充功能是由擴充功能強制執行由管理員設定的政策。
manifest.json 範例
storage.managed_schema
屬性代表副檔名中的一個檔案,其中包含政策結構定義。
{
"name": "My enterprise extension",
"storage": {
"managed_schema": "schema.json"
},
...
}
隨後 Chrome 會從基礎作業系統和 Google Apps 載入這些政策,以供已登入的使用者使用。偵測到政策變更時,會觸發 storage.onChanged
事件。您可以在 chrome://policy 驗證 Chrome 載入的政策。
結構定義格式
JSON 結構定義格式有一些 Chrome 的額外規定:
- 頂層結構定義必須包含
object
類型。 - 頂層
object
不得包含additionalProperties
。宣告的properties
是這項擴充功能的相關政策。 - 每個結構定義都必須包含一個
$ref
值或只有一個type
。
如果結構定義無效,Chrome 就不會載入擴充功能,並指出結構定義未通過驗證的原因。如果政策值與結構定義不符,storage.managed
API 就不會發布該政策值。
結構定義範例
{
"type": "object",
// "properties" maps an optional key of this object to its schema. At the
// top-level object, these keys are the policy names supported.
"properties": {
// The policy name "AutoSave" is mapped to its schema, which in this case
// declares it as a simple boolean value.
// "title" and "description" are optional and are used to show a
// user-friendly name and documentation to the administrator.
"AutoSave": {
"title": "Automatically save changes.",
"description": "If set to true then changes will be automatically saved.",
"type": "boolean"
},
// Other simple types supported include "integer", "string" and "number".
"PollRefreshRate": {
"type": "integer"
},
"DefaultServiceUrl": {
"type": "string"
},
// "array" is a list of items that conform to another schema, described
// in "items". An example to this schema is [ "one", "two" ].
"ServiceUrls": {
"type": "array",
"items": {
"type": "string"
}
},
// A more complex example that describes a list of bookmarks. Each bookmark
// has a "title", and can have a "url" or a list of "children" bookmarks.
// The "id" attribute is used to name a schema, and other schemas can reuse
// it using the "$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" }
}
}
}
}
}