與 local 和 sync 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" }
}
}
}
}
}