Linux Creative Group

Hpricot – Dig The Impossible With Ruby

By: Subhransu Behera arya.subhransu@gmail.com

What’s Special?

Ruby !!!

So … Let’s See ! •  Dynamic

•  EasytoLearn•  Easytomaintainandgrow

•  ConvenientShort‐CutsEx:Str=“LinuxCrea=veGroup”

Str_join=Str.split(““).join(“+”)

•  Transparent,codefaster•  FewSyntaxErrors,FewerBugs•  It’sFun

Ruby Gems

•  PackageManagementSystemforRubyApplica=onsandLibraries

•  ResolveDependencies.•  ProvidesCentralRepositoryofSoUware.•  OneCommandRules: ‐geminstall<gem_name>

•  CanHaveyourOwnLocalGemServer ‐geminstall<gem_name>‐‐source<gem_server_ip_and_port>

Hpricot makes it easy to Parse

Hpricot

•  Pullinforma=onfromvirtuallyanywebsite.

•  SearchbyElementID,Tags,CSSSelectors.•  ParseHTMLincludingbrokenHTML•  UpdateHTML

•  Usethisdataanywhereandanywayyouwant!•  ParsebyXPathfordirectlyparsinganelement.•  Let’ssee….Howitworks.

Let’s Parse A Badly Designed Site !!

•  h^p://www.worldweather.org•  It’sasitethatprovidesweatherinforma=onfordifferentloca=onsacrosstheglobe.

•  Inthemainpagetheyhaveabadlynestedtablestructure!!

•  AnidealWeb‐DevelopercouldhaveputthemnicelyindivswithmeaningfulIDs.

•  Butlet’sfacethetruthandparsetheCountryNamesandtheirURLs.

Easy Steps – 1. Open The Site

Easy Steps – 2. Inspect With Firebug

Easy Steps – 3. Copy X-Path of the Element

Easy Steps – 4. Parse By X-Path Using Hpricot

Use some Logic & You’ll Get

Just Try it Out

Questions?

References

•  RubyProgrammingLanguage:h^p://www.ruby‐lang.org/en/

•  Hpricot:h^p://code.whytheluckys=ff.net/hpricot/

•  X‐Path:h^p://en.wikipedia.org/wiki/XPath•  Firebug:h^p://gecirebug.com/

Thanks