View source for Prototyping 2013-09-23 (Networked Media)

{{underconstruction}}

Sept 23 2013: 1.02 "Turtles & Ducks"

== Promiscous interfaces ==

Generally the interesting things you can do with a programming language are provided by specific libraries. A code library is like a software application that you use via programming. Code written for a specific library often remains "glued" to it in the sense that if the specific library isn't available on another platform, or changes, the code will either not work or break. A degree of "promiscuity" or in this case robustness occurs when the "bindings" are less specific and code can change on "both sides" of the abstraction of a libraries interface allowing changes in one to not break the other.

Python supports a flexible concept of typing sometimes called [[Wikipedia:Duck typing|duck typing]]. What if we secretly replaced our turtle with another turtle trained to respond in exactly the same way as the one built-in to Python, but with a alternative agenda ;)

== Some tools + concepts ==

* [[Inkscape]] A free-software [[Vector graphics]] editor
* [[XML]] A standard way of creating (text) documents using "markup" with tags, designed for "interoperability"
* [[SVG]] An [[wikipedia:open standard|open standard]] for vector graphics, based on XML
* [[Inkscape Plugin]] A ([[Python]]) program that transforms an SVG file, typically run from within the Inkscape interface

== Rough Notes ==

* Inkscape: XML Editor
* SVG: Open in a text editor... draw by typing, search and replace

== Turtle Vectors ==

[[Seymour]]!

== New possibilities in the intersection of tools ==
* Inkscape: Apply path tools to a resulting drawing (need good example -- how to join nodes ?!)
* Python: Load a JSON feed (following Max's example?)

== Inkscape forums ==

Results for search "Joining nodes inkscape":

* http://www.inkscapeforum.com/viewtopic.php?f=28&t=12935
* http://www.youtube.com/watch?v=cGJi5sXxSfQ
* http://imagesbyheatherm.wordpress.com/2009/10/09/joining-lines-in-inkscape-using-the-node-tool/

== Afternoon ==

Practice with Seymour

Extra: Think about other Inkscape/Python plugins

== Reading an RSS Feed as JSON in Python ==

The following website can convert an RSS feed into JSON:

 http://ajax.googleapis.com/ajax/services/feed/load?v=1.0&q=

So to convert the BBC's news feed:

 http://feeds.bbci.co.uk/news/rss.xml

You could use this URL:

 http://ajax.googleapis.com/ajax/services/feed/load?v=1.0&q=http://feeds.bbci.co.uk/news/rss.xml

== About embedding SVG ==

You can place an SVG "inline" (ie cut and paste the code into an HTML page).

In addition, there are different ways to embed an external SVG image, see:

http://tecfa.unige.ch/guides/svg/ex/html5/circle.html

== Examples ==

Reading from a feed...
<source lang="python">
import urllib2
import json

# url = "http://ajax.googleapis.com/ajax/services/feed/load?v=1.0&q=http://feeds.bbci.co.uk/news/rss.xml"
url = "http://gdata.youtube.com/feeds/api/standardfeeds/top_rated?v=2&alt=jsonc"

f = urllib2.urlopen(url)

data = json.load(f)
# things = data['responseData']['feed']['entries']
things = data['data']['items']
for i in things:
    print i['title']
</source>


Now using Seymour:
<source lang="python">
import urllib2
import json

# url = "http://ajax.googleapis.com/ajax/services/feed/load?v=1.0&q=http://feeds.bbci.co.uk/news/rss.xml"
url = "http://gdata.youtube.com/feeds/api/standardfeeds/top_rated?v=2&alt=jsonc"

f = urllib2.urlopen(url)

data = json.load(f)
# things = data['responseData']['feed']['entries']
things = data['data']['items']
for i in things:
    turtle.pd()
    turtle.fd(100)
    turtle.pu()
    turtle.text(i['title'])
    turtle.fd(10)
</source>



* http://archipels.be is a website project I worked on that uses SVG+html plus some other random tools to make a browser of avant-garde music

The project made use of the following code:

* http://code.google.com/p/svgpan/
* http://www.cyberz.org/projects/SVGPan/tiger.svg  ... cue 80s music!