there once was a command linenav filesystem, launch apps, write scripts

Program

Input Output

lots of power in a bit of infrastructure involving input and output

Program

STDIN STDOUT

STDERR

stdin, stdout were available to reroute wherever the user wantedmost common use was chaining commands together: piping

Program

STDIN STDOUT

STDERR

Infrastructure

this was an amazing amount of infrastructure based on a very simple idea

1977and we’ve had it since 1977

1997fast foward 20 years just after commercialization of internet to a perl conferencejon udell talks about websites as data sources that can be reused and remixedtoday that idea isn’t very novel

1997

a new programming paradigm that takes the whole Internet

as its platform

he also talked about a new programming paradigmi don’t think we’re there yetbut this inspired ...

“What is the equivalent of the pipe in the age of the web?”

tim oreilly to ask in 2000...

there seems to be resounding consensus the answer is feedsthey sound good in theory

it makes you think of feeds like in the telecom world

data coming directly to you

but we know that’s not how it works

?

instead we have to go request the data

then it gives it to us. and we do this over and over.

?

client side mashups might be able to get by with this

?

but when you start talking about persistent web applications, it becomes a bit more work

?

• Crontab / Daemon• Parsing• Caching

?

• Crontab / Daemon• Parsing• Caching

this is just too much work sometimes

the other problem i have is with the command line metaphor for web apps

Start Stop

Command-line Application

because a command line application is linear. it starts, runs, and stops

AlwaysRunning

WebApplication

web apps are always running.a better metaphor for this is a running process or daemon

here we have some daemons.this is ps doomso using this metaphor, how do daemons communicate?

IPC?Inter process communication

ipc?

lolh4x

stfun00b

...yeah. my experience with ipc was pretty bad. ipc usually involves some sort of shared memory mechanism, like a queue

it turns out amazon provides a queue web servicebut with a third party queue you only defer the pollingit doesn’t solve the problem, its just fancier rss

so this is not the solution, and probably why not too many people use or know of it

Real-timeEfficient

Easy

Web Hooks

web hooks are user defined callback URLs that point to a web script to run on a certain event.you can call them other things...

Web Hooks• User Callbacks• Triggers• Event Handlers• “Plugouts”

web hooks are user defined callback URLs that point to a web script to run on a certain event.you can call them other things...

to implement web hooks, you generally provide a ui--

for the user to specify a url for events

http://example.com/post-commit.php

Infrastructure

http://example.com/post-commit.php

what this does is creates powerful infrastructure that might not be obvious at the surface

Easy for Vendors

the idea is that it’s easy for vendors to integrate

the main mechanism is a standard http post, which is trivial in most environments

Easy (enough) for Users

it’s also very open and easy for the users, which will generally be advanced users, but can easily be taken advantage of by novice users

as a user, to take advantage of hooks, you’d write a script to handle an event, like the committhis is a very simple script

“Internet”

so what the user would do

“Internet”

is put that script up on the internet

“Internet”

then they’d go to the hook settings page

and hook the commit event up to their script

then as the user interacts with devjavu

Commit!

and they make a commit, it fires a post to their script

Commit!

the script runs, and send an email to the mailing list

Commit!

this makes the user a happy cookie. and this is a trivial example, using only on web service. imagine using the api of another in the hook script and chaining these things together

Commit!

but even in this simple example, you see the power it gives to the user and to the data that we’re trying to “open up” to our users

Program

STDIN STDOUT

back to piping on the command line, remember that it was simple infrastructure that gave you tremendous power, and one of the key components was making it easy to chain commands

Program

STDIN

we wouldn’t be able to do it without the output part of it

Web App

API

unfortunately that’s how the web is today. the only output you can get is by using the input (api, feed)

Web App

API Hooks

web hooks gives us this output, and when *combined* with the input of api’sit will give us and our user tremendous power that i think will really push the webinto being a new programmable paradigm

Program the Web

the possibilities become very rich and i’ve thought about it a lotthere’s probably a lot moreimagine realtime data syncronizationor a chain of events that makes these apps work together in a way you’ve never imagined

Fin

Questions?

blogrium.com

SuperHappyDevHouse

Web App

API Hooks

web hooks gives us this output, and when *combined* with the input of api’sit will give us and our user tremendous power that i think will really push the webinto being a new programmable paradigm