Class | WWW::Mechanize::PluggableParser |
In: |
lib/www/mechanize/pluggable_parsers.rb
|
Parent: | Object |
This class is used to register and maintain pluggable parsers for Mechanize to use.
A Pluggable Parser is a parser that Mechanize uses for any particular content type. Mechanize will ask PluggableParser for the class it should initialize given any content type. This class allows users to register their own pluggable parsers, or modify existing pluggable parsers.
PluggableParser returns a WWW::Mechanize::File object for content types that it does not know how to handle. WWW::Mechanize::File provides basic functionality for any content type, so it is a good class to extend when building your own parsers.
To create your own parser, just create a class that takes four parameters in the constructor. Here is an example of registering a pluggable parser that handles CSV files:
class CSVParser < WWW::Mechanize::File attr_reader :csv def initialize(uri=nil, response=nil, body=nil, code=nil) super(uri, response, body, code) @csv = CSV.parse(body) end end agent = WWW::Mechanize.new agent.pluggable_parser.csv = CSVParser agent.get('http://example.com/test.csv') # => CSVParser
Now any page that returns the content type of ‘text/csv’ will initialize a CSVParser and return that object to the caller.
To register a pluggable parser for a content type that pluggable parser does not know about, just use the hash syntax:
agent.pluggable_parser['text/something'] = SomeClass
To set the default parser, just use the ‘defaut’ method:
agent.pluggable_parser.default = SomeClass
Now all unknown content types will be instances of SomeClass.
CONTENT_TYPES | = | { :html => 'text/html', :pdf => 'application/pdf', :csv => 'text/csv', :xml => 'text/xml', } |
default | [RW] |
# File lib/www/mechanize/pluggable_parsers.rb, line 55 55: def initialize 56: @parsers = { CONTENT_TYPES[:html] => Page } 57: @default = File 58: end
# File lib/www/mechanize/pluggable_parsers.rb, line 84 84: def [](content_type) 85: @parsers[content_type] 86: end
# File lib/www/mechanize/pluggable_parsers.rb, line 88 88: def []=(content_type, klass) 89: @parsers[content_type] = klass 90: end
# File lib/www/mechanize/pluggable_parsers.rb, line 76 76: def csv=(klass) 77: register_parser(CONTENT_TYPES[:csv], klass) 78: end
# File lib/www/mechanize/pluggable_parsers.rb, line 68 68: def html=(klass) 69: register_parser(CONTENT_TYPES[:html], klass) 70: end
# File lib/www/mechanize/pluggable_parsers.rb, line 60 60: def parser(content_type) 61: content_type.nil? ? default : @parsers[content_type] || default 62: end
# File lib/www/mechanize/pluggable_parsers.rb, line 72 72: def pdf=(klass) 73: register_parser(CONTENT_TYPES[:pdf], klass) 74: end
# File lib/www/mechanize/pluggable_parsers.rb, line 64 64: def register_parser(content_type, klass) 65: @parsers[content_type] = klass 66: end