ISSUE-1468 [DOC] JMAP Download All custom extension (#1485)

docs/modules/ROOT/pages/tmail-backend/jmap-extensions/downloadAll.adoc

@@ -0,0 +1,41 @@
+= JMAP Download All
+:navtitle: JMAP Download All
+
+This extension allows users, when reading an email, to download all attachments at once. The attachments are being compressed
+and delivered to the user in a zip file.
+
+== Additions to the capability object
+
+Servers supporting the JMAP Download All extension need to advertise it through the session capabilities:
+....
+com:linagora:params:downloadAll
+....
+
+The capability needs to advertise the following specified download all attachments route.
+
+== Specification
+
+The JMAP Download All extension is defined by a new JMAP route following this pattern:
+
+....
+GET /jmap/downloadAll/{accountId}/{emailId}?name={name}
+....
+
+Where:
+
+- `accountId`: *String*. The user account id.
+- `emailId`: *String*. The email id to download all attachments from.
+- `name`: *String*. The name of the zip file.
+
+It returns all attachments of that email compressed into a zip file.
+
+Error codes:
+
+- `401`: no rights to access the mail and its attachments
+- `404`: email not found or no attachments present in the email
+
+Notes:
+
+- When multiple files have the same name, we only keep and return the latest one in the zip file.
+
+

docs/modules/ROOT/pages/tmail-backend/jmap-extensions/index.adoc

@@ -48,6 +48,7 @@ from the blob id of the calendar file (.ics).
  - link:jmapLabels.adoc[com:linagora:params:jmap:labels] allows users to manipulate emails by labels.
  - link:jmapSettings.adoc[com:linagora:params:jmap:labels] allows clients to store per-user settings on the backend side.
  - link:publicAssets.adoc[com:linagora:params:public:assets] allows clients to store images as public assets to use on their TMail signature.
+ - link:downloadAll.adoc[com:linagora:params:downloadAll] allows clients to download all attachments of a mail at once compressed in a zip file.
 
 === Standard JMAP extensions