Module: TaliaCore::ActiveSourceParts::Finders

Included in:
TaliaCore::ActiveSource
Defined in:
lib/talia_core/active_source_parts/finders.rb

Overview

All class methods that are used for finding sources.

Instance Method Summary collapse

Instance Method Details

#count(*args) ⇒ Object

Modify the count helper so that it can use the advanced options of the ActiveSource #find routine



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# File 'lib/talia_core/active_source_parts/finders.rb', line 50

def count(*args)
  if((options = args.last).is_a?(Hash))
    options.to_options!
    options.delete(:prefetch_relations) # This is not relevant for counting
    prepare_options!(options)
  end
  super
end

#find(*args) ⇒ Object

Finder also accepts uris as “ids”. There are also some additional options that are accepted:

:find_through

accepts and array with an predicate name and an object value/uri, to search for predicates that match the given predicate/value combination

:type

specifically looks for sources with the given type.

:find_through_inv

like :find_through, but for the “inverse” lookup

:prefetch_relations

if set to “true”, this will pre-load all semantic relations for the sources (experimental, not fully implemented yet)



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# File 'lib/talia_core/active_source_parts/finders.rb', line 18

def find(*args)
  prefetching = false
  if(args.last.is_a?(Hash))
    options = args.last
    options.to_options!
    
    # Hack the "default" ordering
    options[:order] = 'id' if(options[:order] == :default)
    
    prefetching =  options.delete(:prefetch_relations)
    if(options.empty?) # If empty we remove the args hash, so that the 1-param uri search works
      args.pop
    else
      prepare_options!(options)
    end
  end
  
  result = if(args.size == 1 && (uri_s = uri_string_for(args[0])))
    src = super(:first, :conditions => { :uri => uri_s })
    raise(ActiveRecord::RecordNotFound, "Not found: #{uri_s}") unless(src)
    src
  else
    super
  end

  prefetch_relations_for(result) if(prefetching)

  result
end

#find_by_partial_local(namespace, local_part, options = {}) ⇒ Object

Find the Sources within the given namespace by a partial local name



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# File 'lib/talia_core/active_source_parts/finders.rb', line 77

def find_by_partial_local(namespace, local_part, options = {})
  namesp = N::URI[namespace]
  return [] unless(namesp)
  find(:all, { 
    :conditions => [ 'uri LIKE ?', "#{namesp.uri}#{local_part}%" ], 
    :order => "uri ASC"}.merge!(options))
end

#find_by_partial_uri(id, options = {}) ⇒ Object

Find the fist Source that matches the given URI. It’s useful for admin pane, because users visit:

/admin/sources/<source_id>/edit

but that information is not enough, since we store into the database the whole reference as URI:

http://localnode.org/av_media_sources/source_id



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# File 'lib/talia_core/active_source_parts/finders.rb', line 91

def find_by_partial_uri(id, options = {})
  find(:all, { :conditions => ["uri LIKE ?", '%' + id + '%'] }.merge!(options))
end

#find_by_uri_token(token, options = {}) ⇒ Object

Find a list of sources which contains the given token inside the local name. This means that the namespace it will be excluded.

Sources in system:
  * http://talia.org/one
  * http://talia.org/two

Source.find_by_uri_token('a') # => [ ]
Source.find_by_uri_token('o') # => [ 'http://talia.org/one', 'http://talia.org/two' ]

NOTE: It internally use a MySQL function, as sql condition, to find the local name of the uri.



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# File 'lib/talia_core/active_source_parts/finders.rb', line 70

def find_by_uri_token(token, options = {})
  find(:all, { 
    :conditions => [ "LOWER(SUBSTRING_INDEX(uri, '/', -1)) LIKE ?", '%' + token.downcase + '%' ], 
    :order => "uri ASC" }.merge!(options))
end