Today, the Web, based on URLs and HTTP-style protocols is widely
recognized as a platform in its own right. This platform emerged
over time — to me, Web APIs arrived in the late 90's when I
observed the following with respect to my own behavior on many
popular sites:
- I opened a Web page that took a while to load (remember, I
was still using Emacs-W3),
- I then searched through the page to find a form-field that
I filled out, e.g., start and end destinations on Yahoo
Maps,
- I hit submit, and once again waited for a heavy-weight
HTML page to load,
- And finally, I hunted through the rendered content to find
what I was looking for.
This pattern repeated across a wide-range of interactive Web
sites ranging from AltaVista for search (this was pre-Google),
Yahoo Maps for directions, and Amazon for product searches to
name but a few. So I decided to automate away the pain by
creating Emacspeak module emacspeak-websearch that did the
following:
- Prompt via the minibuffer for the requisite fields,
- Consed up an HTTP GET URL,
- Retrieved this URL,
- And filtered out the specific portion of the HTML DOM that
held the generated response.
Notice that the above implementation hard-wires the CGI parameter
names used by a given Web application into the code implemented
in module emacspeak-websearch. REST as a design pattern had not
yet been recognized, leave alone formalized, and module
emacspeak-websearch was initially decryed as being fragile.
However, over time, the CGI parameter names remained fixed — the
only things that have required updating in the Emacspeak
code-base are the content filtering rules that extract the
response — for popular services, this has averaged about one to
two times a year.
I later codified these filtering rules in terms of XPath, and
also integrated XSLT-based pre-processing of incoming HTML
content before it got handed off to Emacs-W3 — and yes,
Emacs/Advice once again came in handy with respect to injecting
XSLT pre-processing into Emacs-W3!
Later, in early 2000, I created companion module
emacspeak-url-templates — partially inspired by Emacs'
webjump module. URL templates in Emacspeak leveraged the
recognized REST interaction pattern to provide a large collection
of Web widgets that could be quickly invoked to provide rapid
access to the right pieces of information on the Web.
The final icing on the cake was the arrival of RSS and Atom feeds
and the consequent deep-linking into content-rich sites — this
meant that Emacspeak could provide audio renderings of useful
content without having to deal with complex visual navigation!
While Google Reader existed, Emacspeak provided a light-weight
greader client for managing ones feed subscriptions; with the
demise of Google Reader, I implemented module emacspeak-feeds
for organizing feeds on the Emacspeak desktop. A companion
package emacspeak-webspace implements additional goodies
including a continuously updating ticker of headlines taken from
the user's collection of subscribed feeds.
