Example: Language Translation
The manifest for a language translation Motion service might look like so:
{
“name”: “translate”,
“description”: “Translates a message from one language to another”,
“requests”: [ “subject”, “body” ],
“requires”: [ ],
“modifies”: [ “subject”, “body”, “language” ],
“configurable”: true,
“endpoint”: “https://translate.example.com/translate/”
}
Note that this service has "configurable": true. That means that if we then POST a blank document to it, the service will create a new configuration instance, and serve up a human-interactive page with which may be used to select the desired configuration settings.
The mechanisms used to store these settings within the service are not defined by Motion; we care only that we now have a path at which our settings may be changed and to which we will POST our messages to be processed.
C:POST /translate/translate/ HTTP/1.1
C:Content-Length: 0
C:
S:HTTP/1.1 201 Created
S:Location: /translate/options/a1e9
S:
We may now POST the required fields from our message data to the service, and receive the translated versions.
C:POST /translate/options/a1e9 HTTP/1.1
C:Content-Type: application/json
C:
C:{
C: “subject”: “Bonjour!”,
C: “body”: {
C: “text”: “j'oublie tout”,
C: “html”: “<html><body>j'oub...
C: }
C:}
C:
S:HTTP/1.1 200 Ok
S:Content-Type: application/json
S:
S:{
S: “language”: “en”,
S: “subject”: “Hello!”,
S: “body”: {
S: “text”: “I forget everything”,
S: “html”: “<html><body>I forg...
S: }
S:}
An improvement over this initial design might be to create two services, a language identifier and a language translator. The first would only determine the language used in the message.
C:POST /whatlanguage HTTP/1.1
C:Content-Type: application/json
C:
C:{
C: “subject”: “Bonjour!”,
C: “body”: {
C: “text”: “j'oublie tout”,
C: “html”: “<html><body>j'oub...
C: }
C:}
C:
S:HTTP/1.1 200 Ok
S:Content-Type: application/json
S:
S:{
S: “language”: “en”
S:}
This way, an MTA (or archiver, or mail client, or anything) would then have the option to act in a number of ways based on what language is detected, including using the full translation service.
if (language == “de” ||
language == “fr” ||
language == “es”
) {
translate(en);
} else {
/* Is this spam? */
delete();
}