With all the various technological terms, acronyms, and buzzwords being thrown about (with just about any technical matter), it sometimes becomes rather easy to get lost in the chase. To help keep ourselves grounded this primer will translate HTTP communications into very simple terms that will make sense to any OpenInsight developer.
HTTP communications is analogous to making a function call. Consider these similarities:
- Functions are executed from a calling operation, typically another routine or an event handler. Likewise, HTTP communications are initiated from a calling operation, typically a request from a web browser or other HTTP-aware client. HTTP Requests are well-defined operations which will be touched upon through this document.
- The caller (or client) waits until the function (or server handling the HTTP request) is finished. While other factors may interrupt the wait (such a timeout or critical disconnection), the normal expectation is a response of some kind.
- Functions return the results of a request back to the caller, typically through a return variable. Some programming environments might also allow arguments to be modified or global variables to be updated. Likewise, HTTP communications also return the results of a request back to the caller. This is referred to as the HTTP Response, another well-defined operation. HTTP Responses can either be handled by a server-side program or through the retrieval of a local file.
With that high-level comparison in mind, let’s examine the anatomy of the two basic HTTP means of communication: Requests and Responses:
