The Power of the URL-Line

By Jon Udell

August 20, 2001

(The Power of the URL-Line :  Page 1 of 1 )

RPC-style services don't replace the humble URL

There is often more value in getting XML out of a web service than in sending XML into a service. In such cases, the human-friendly URL-line offers distinct advantages.

For years I used the phrase "URL command line" to describe the browser's Location (Netscape) or Address (MSIE) window — that is, the place where you type or paste URLs. My friend Rael Dornfest has more recently coined the more elegant term URL-line.

Like the traditional command line, the URL-line is available for use both by humans, who can type it or paste it or click on it, and by programs, which can invoke it. Unlike the traditional command line, the URL-line tends to be self-documenting — a key point which I think is often overlooked. When you read the man page for a UNIX command, the description is given in formal and abstract terms. You might find some examples at the end of the man page, but you might not. The URL-line's syntax, on the other hand, is quite often demonstrated as a consequence of normal interactive use of web pages. This documentation effect occurs because web pages can be, at the same time, documents and software. The blending of these two styles meant that first-generation web APIs were:

• Easily discovered

  That's true, anyway, for GET requests. POST requests, which do not reveal syntax on the URL-line, made API discovery harder. See my earlier column, Website API Discovery, for some tips on how to expose URL-line syntax that's been hidden from view.

  One of the key drivers of the Web's explosive growth was its radical transparency. Like the BYTE.com > Tangled in the Threads > 2001 > August