XMLTV::Grab_XML - Man Page
Perl extension to fetch raw XMLTV data from a site
Synopsis
package Grab_XML_rur; use base 'XMLTV::Grab_XML'; sub urls_by_date( $ ) { my $pkg = shift; ... } sub country( $ ) { my $pkg = shift; return 'Ruritania' } # Maybe override a couple of other methods as described below... Grab_XML_rur->go();
Description
This module helps to write grabbers which fetch pages in XMLTV format from some website and output the data. It is not used for grabbers which scrape human-readable sites.
It consists of several class methods (package methods). The way to use it is to subclass it and override some of these.
Methods
- XMLTV::Grab_XML->date_init()
Called at the start of the program to set up Date::Manip. You might want to override this with a method that sets the timezone.
- XMLTV::Grab_XML->urls_by_date()
Returns a hash mapping YYYYMMDD dates to a URL where listings for that date can be downloaded. This method is abstract, you must override it.
Arguments: the command line options for --config-file and --quiet.
- XMLTV::Grab_XML->xml_from_data(data)
Given page data for a particular day, turn it into XML. The default implementation just returns the data unchanged, but you might override it if you need to decompress the data or patch it up.
- XMLTV::Grab_XML->configure()
Configure the grabber if needed. Arguments are --config-file option (or undef) and --quiet flag (or undef).
This method is not provided in the base class; if you don't provide it then attempts to --configure will give a message that configuration is not necessary.
- XMLTV::Grab_XML->nextday(day)
Bump a YYYYMMDD date by one. You probably shouldn't override this.
- XMLTV::Grab_XML->country()
Return the name of the country you're grabbing for, used in usage messages. Abstract.
- XMLTV::Grab_XML->usage_msg()
Return a command-line usage message. This calls
country()
, so you probably need to override only that method.- XMLTV::Grab_XML->get()
Given a URL, fetch the content at that URL. The default implementation calls XMLTV::Get_nice::get_nice() but you might want to override it if you need to do wacky things with http requests, like cookies.
Note that while this method fetches a page,
xml_from_data()
does any further processing of the result to turn it into XML.- XMLTV::Grab_XML->go()
The main program. Parse command line options, fetch and write data.
Most of the options are fairly self-explanatory but this routine also calls the XMLTV::Memoize module to look for a --cache argument. The functions memoized are those given by the
cachables()
method.- XMLTV::Grab_XML->cachables()
Returns a list of names of functions which could reasonably be memoized between runs. This will normally be whatever function fetches the web pages - you memoize that to save on repeated downloads. A subclass might want to add things to this list if it has its own way of fetching web pages.
- XMLTV::Grab_XML->remove_early_stop_times()
Checks each stop time and removes it if it's before the start time.
Argument: the XML to correct Returns: the corrected XML
Author
Ed Avis, ed@membled.com