Monthly Archives: November 2005

Escaping URLs vs escaping HTML

Programming, Python, ruby, Scripting

I often get confused between two types of escaping you need to do when developing web applications: URL escaping and HTML escaping. This is a short note about when should you use what.

URL Escaping (or HTTP encoding or URL encoding) is used to escape the characters not allowed to be permitted for a URL (e.g. To generate the query string to be passed from forms). The way to encode these characters is to use % and hexadecimal code for the ASCII character code. e.g. %20 for space character. (RFC 1738 defines the syntax and symantics of URLs)

HTML escaping is used when writing HTML documents where you do not want the browser to interpret the HTML special characters. e.g. You need to use & to represent &. Wikipedia has an article describing escape sequences for comonly used special HTML characters.

Scripting languages have libraries which can do URL and HTML encoding and decoding for you:

Python: urllib.quote and urllib.unquote , ???, ???

Ruby: CGI::escape, CGI::unescape, CGI::escapeHTML, CGI::unescapeHTML

Playing mp3 links right in your browser

Internet, Programming, Scripting

The del.icio.us folks have a nifty javascript piece of code which adds a small button to all the mp3 links on your webpage. (This infact embeds a small shockwave/flash script for each link). All you need to do is include the following code in the head section of your webpage:


<script type="text/javascript" src="http://del.icio.us/js/playtagger"></script>

Here is a link to their webpage (Notice the small play button just before the link to audio file.

Here are some popular audio links contributed by del.icio.us users.

Update: And then there is Yahoo! Media player with nicer look and more features. You just need to add
<script type="text/javascript" src="http://mediaplayer.yahoo.com/js"></script>

at the end of the html (just before closing </body>)

Yahoo Geocoding in ruby…

Internet, Programming, ruby, Scripting, webdev, , , , , , , ,

Find lattitude and longitude of any address

Yahoo just released a new beta of their maps webservice. Here is a small ruby script (inspired by Rasmus's PHP code ) that I wrote that returns Lattitude, Longitude of the address provided...

require 'open-uri'
require "rexml/document"
include REXML
url='http://api.local.yahoo.com/MapsService/V1/geocode?appid=yahoomap.rb&location='
puts 'Enter Location: '
address=gets
address=URI.escape(address)
result=URI(url+address).read
doc = Document.new result
r=doc.elements["/ResultSet/Result"]
print "Precision: ", r.attributes["precision"],"\n"
r.children.each { |c| print c.name, " : ",c.text,"\n"}

Update: Here is a link to the script in github or to the .