REST API/Considerations

Important: To use the REST APIs, you must be logged into the platform. The response to the login request includes a session ID that must be present in each REST request you make. The cookie string that accompanies the login response contains additional information, like the load balancer key, which identifies the platform instance you logged in to. That key must be present in all subsequent session requests to insure that they go to the same platform instance. In your programs, you achieve that goal by including the cookie string in each request. (Browsers do that automatically, so once you are logged in, REST APIs in JSP pages "just work". But when writing a program, you need to code that behavior.) Learn more: REST API Sample programs

• The REST APIs are granular (each call operates on a single entity)
• Each REST API call is treated as a single transaction
• In most cases, APIs have a direct one-to-one mapping with the UI
• Data input and output can be in either XML or JSON format.
• The content types for request data are application/xml and application/json.
  (text/xml is not supported.)
• It is necessary to login to the platform before making a REST API call (and logout afterwards)
• All REST API calls execute within the context of the User that is logged in. As with all UI actions, this means that any subsequent REST API calls (to access levels, data visibility, team membership, etc.), are governed by the Data Access Permissions granted to the User.
• REST API calls are broadly categorized as Data API or Metadata API (excluding login/logout)
• Data calls can span multiple objects, for example, the owner field in an object, or Lookups (foreign key relationships) to some other objects

• The REST API implements the database CRUD model (Create, Read/Select, Update, Delete) using HTTP protocol requests (POST, GET, UPDATE and DELETE).

CRUD Action	HTTP Method
Create	POST
Read/Select	GET
Update	PUT
Delete	DELETE

• Field elements are optional in record updates. If a field is missing, existing data in that field is unaffected. If a field is present, but empty, any existing data in that field is deleted.
• When the database value for a checkbox field is null, the REST API returns 0. (So the value is always 1 (checked) or 0 (unchecked), whether or not the field has been initialized.)

Note: When specifying a URL in code, any special characters (characters other than letters and numbers) need to be encoded. For example, a space character can be encoded using either + or %20. (Browsers typically take care of encoding URLs entered into the address bar--so the URL displayed after visiting a page may differ somewhat from the one that was initially entered.) Here are some typical encodings: space + % %20 or + %2B %25 So: Instead of Use & (A&B) space (A B) %26 (A%26B) %20 (A%20B) It can be hard to get be hard to get the encoding right, so it's desirable to use a language library designed for the purpose. Learn more: URL Encoding in HTML Encode a URL in JavaScript URLEncoder class for Java