Class: Mechanize::PluggableParser
- Inherits:
-
Object
- Object
- Mechanize::PluggableParser
- Defined in:
- lib/mechanize/pluggable_parsers.rb
Overview
Mechanize allows different parsers for different content types. Mechanize uses PluggableParser to determine which parser to use for any content type. To use your own parser or to change the default parsers, register them with this class through Mechanize#pluggable_parser.
The default parser for unregistered content types is Mechanize::File.
The module Mechanize::Parser provides basic functionality for any content type, so you may use it in custom parsers you write. For small files you wish to perform in-memory operations on, you should subclass Mechanize::File. For large files you should subclass Mechanize::Download as the content is only loaded into memory in small chunks.
When writing your own pluggable parser, be sure to provide a method #body that returns a String containing the response body for compatibility with Mechanize#get_file.
Example
To create your own parser, just create a class that takes four parameters in the constructor. Here is an example of registering a parser that handles CSV files:
require 'csv'
class CSVParser < 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 = Mechanize.new
agent.pluggable_parser.csv = CSVParser
agent.get('http://example.com/test.csv') # => CSVParser
Now any response with a content type of ‘text/csv’ will initialize a CSVParser and return that object to the caller.
To register a parser for a content type that Mechanize does not know about, use the hash syntax:
agent.pluggable_parser['text/something'] = SomeClass
To set the default parser, use #default:
agent.pluggable_parser.default = Mechanize::Download
Now all unknown content types will be saved to disk and not loaded into memory.
Constant Summary collapse
- CONTENT_TYPES =
{ :html => 'text/html', :wap => 'application/vnd.wap.xhtml+xml', :xhtml => 'application/xhtml+xml', :pdf => 'application/pdf', :csv => 'text/csv', :xml => 'text/xml', }
Instance Attribute Summary collapse
-
#default ⇒ Object
Returns the value of attribute default.
Instance Method Summary collapse
-
#[](content_type) ⇒ Object
Retrieves the parser for
content_type
content. -
#[]=(content_type, klass) ⇒ Object
Sets the parser for
content_type
content toklass
. -
#csv=(klass) ⇒ Object
Registers
klass
as the parser for text/csv content. -
#html=(klass) ⇒ Object
Registers
klass
as the parser for text/html and application/xhtml+xml content. -
#initialize ⇒ PluggableParser
constructor
A new instance of PluggableParser.
-
#parser(content_type) ⇒ Object
Returns the parser registered for the given
content_type
. -
#pdf=(klass) ⇒ Object
Registers
klass
as the parser for application/pdf content. -
#register_parser(content_type, klass) ⇒ Object
:nodoc:.
-
#xhtml=(klass) ⇒ Object
Registers
klass
as the parser for application/xhtml+xml content. -
#xml=(klass) ⇒ Object
Registers
klass
as the parser for text/xml content.
Constructor Details
#initialize ⇒ PluggableParser
Returns a new instance of PluggableParser.
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# File 'lib/mechanize/pluggable_parsers.rb', line 72 def initialize @parsers = { CONTENT_TYPES[:html] => Mechanize::Page, CONTENT_TYPES[:xhtml] => Mechanize::Page, CONTENT_TYPES[:wap] => Mechanize::Page, 'image' => Mechanize::Image } @default = Mechanize::File end |
Instance Attribute Details
#default ⇒ Object
Returns the value of attribute default.
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# File 'lib/mechanize/pluggable_parsers.rb', line 70 def default @default end |
Instance Method Details
#[](content_type) ⇒ Object
Retrieves the parser for content_type
content
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# File 'lib/mechanize/pluggable_parsers.rb', line 147 def [](content_type) @parsers[content_type] end |
#[]=(content_type, klass) ⇒ Object
Sets the parser for content_type
content to klass
The content_type
may either be a full MIME type a simplified MIME type (‘text/x-csv’ simplifies to ‘text/csv’) or a media type like ‘image’.
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# File 'lib/mechanize/pluggable_parsers.rb', line 157 def []= content_type, klass register_parser content_type, klass end |
#csv=(klass) ⇒ Object
Registers klass
as the parser for text/csv content
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# File 'lib/mechanize/pluggable_parsers.rb', line 133 def csv=(klass) register_parser(CONTENT_TYPES[:csv], klass) end |
#html=(klass) ⇒ Object
Registers klass
as the parser for text/html and application/xhtml+xml content
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# File 'lib/mechanize/pluggable_parsers.rb', line 111 def html=(klass) register_parser(CONTENT_TYPES[:html], klass) register_parser(CONTENT_TYPES[:xhtml], klass) end |
#parser(content_type) ⇒ Object
Returns the parser registered for the given content_type
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# File 'lib/mechanize/pluggable_parsers.rb', line 86 def parser content_type return default unless content_type parser = @parsers[content_type] return parser if parser mime_type = MIME::Type.new content_type parser = @parsers[mime_type.to_s] || @parsers[mime_type.simplified] || @parsers[mime_type.media_type] || default rescue MIME::InvalidContentType default end |
#pdf=(klass) ⇒ Object
Registers klass
as the parser for application/pdf content
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# File 'lib/mechanize/pluggable_parsers.rb', line 126 def pdf=(klass) register_parser(CONTENT_TYPES[:pdf], klass) end |
#register_parser(content_type, klass) ⇒ Object
:nodoc:
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# File 'lib/mechanize/pluggable_parsers.rb', line 103 def register_parser content_type, klass # :nodoc: @parsers[content_type] = klass end |
#xhtml=(klass) ⇒ Object
Registers klass
as the parser for application/xhtml+xml content
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# File 'lib/mechanize/pluggable_parsers.rb', line 119 def xhtml=(klass) register_parser(CONTENT_TYPES[:xhtml], klass) end |
#xml=(klass) ⇒ Object
Registers klass
as the parser for text/xml content
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# File 'lib/mechanize/pluggable_parsers.rb', line 140 def xml=(klass) register_parser(CONTENT_TYPES[:xml], klass) end |