Class: ARLoader::LoaderBase

Inherits:
Object show all
Defined in:
lib/loaders/loader_base.rb

Direct Known Subclasses

CsvLoader, ExcelLoader, ImageLoader, ProductLoader

Constant Summary collapse

@@name_value_delim =

Enable an entry representing an association to contain multiple lookup name/value sets in default form : Name1:value1, value2|Name2:value1, value2, value3|Name3:value1, value2

E.G. Row for association could have a columns called Size and once called Colour, and this combination could be used to lookup multiple associations to add to the main model

  Size:small            # => generates find_by_size( 'small' )
  Size:large|           # => generates find_by_size( 'large' )
  Colour:red,green,blue # => generates find_all_by_colour( ['red','green','blue'] )

TODO - support embedded object creation/update via hash (which hopefully we should be able to just forward to AR)

 |Category|
 name:new{ :date => '20110102', :owner = > 'blah'}
':'
@@multi_value_delim = 
','
@@multi_assoc_delim =

TODO - support multi embedded object creation/update via hash (which hopefully we should be able to just forward to AR)

 |Category|
 name:new{ :a => 1, :b => 2}|name:medium{ :a => 6, :b => 34}|name:old{ :a => 12, :b => 67}
'|'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(object_class, object = nil, options = {}) ⇒ LoaderBase

Options



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# File 'lib/loaders/loader_base.rb', line 57

def initialize(object_class, object = nil, options = {})
  @load_object_class = object_class

  # Gather list of all possible 'setter' methods on AR class (instance variables and associations)
  ARLoader::MethodMapper.find_operators( @load_object_class )

  @options = options.clone
  @headers = []
  reset(object)
end

Instance Attribute Details

#current_method_detail ⇒ Object

Returns the value of attribute current_method_detail.



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# File 'lib/loaders/loader_base.rb', line 20

def current_method_detail
  @current_method_detail
end

#current_value ⇒ Object

Returns the value of attribute current_value.



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# File 'lib/loaders/loader_base.rb', line 20

def current_value
  @current_value
end

#failed_objects ⇒ Object

Returns the value of attribute failed_objects.



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# File 'lib/loaders/loader_base.rb', line 22

def failed_objects
  @failed_objects
end

#headers ⇒ Object (readonly)

Returns the value of attribute headers.



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# File 'lib/loaders/loader_base.rb', line 17

def headers
  @headers
end

#load_object ⇒ Object

Returns the value of attribute load_object.



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# File 'lib/loaders/loader_base.rb', line 19

def load_object
  @load_object
end

#load_object_class ⇒ Object

Returns the value of attribute load_object_class.



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# File 'lib/loaders/loader_base.rb', line 19

def load_object_class
  @load_object_class
end

#loaded_objects ⇒ Object

Returns the value of attribute loaded_objects.



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# File 'lib/loaders/loader_base.rb', line 22

def loaded_objects
  @loaded_objects
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/loaders/loader_base.rb', line 24

def options
  @options
end

Class Method Details

.set_multi_assoc_delim(x) ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 54

def self.set_multi_assoc_delim(x) @@multi_assoc_delim = x; end

.set_multi_value_delim(x) ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 53

def self.set_multi_value_delim(x) @@multi_value_delim = x; end

.set_name_value_delim(x) ⇒ Object

Used to delimit multiple entries in a single column



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# File 'lib/loaders/loader_base.rb', line 52

def self.set_name_value_delim(x)  @@name_value_delim = x; end

Instance Method Details

#abort_on_failure? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/loaders/loader_base.rb', line 88

def abort_on_failure?
  @options[:abort_on_failure] == 'true'
end

#contains_mandatory?(mandatory_list) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/loaders/loader_base.rb', line 74

def contains_mandatory?( mandatory_list )
  puts "HEADERS", @headers
  [mandatory_list - @headers].flatten.empty?
end

#failed_count ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 96

def failed_count
  @failed_objects.size
end

#find_and_process(klass, column_name, row_data) ⇒ Object

Search method mapper for supplied klass and column, and if suitable association found, process row data into current load_object



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# File 'lib/loaders/loader_base.rb', line 102

def find_and_process(klass, column_name, row_data)
  method_detail = MethodMapper.find_method_detail( klass, column_name )

   
  if(method_detail)
    process(method_detail, row_data)
  else
    @load_object.errors.add_base( "No matching method found for column #{column_name}")
  end
end

#find_or_new(klass, condition_hash = {}) ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 195

def find_or_new( klass, condition_hash = {} )
  @records[klass] = klass.find(:all, :conditions => condition_hash)
  if @records[klass].any?
    return @records[klass].first
  else
    return klass.new
  end
end

#load(input, options = {}) ⇒ Object

kinda the derived classes interface - best way in Ruby ?



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# File 'lib/loaders/loader_base.rb', line 115

def load( input, options = {} )
  raise "WARNING- ABSTRACT METHOD CALLED - Please implement load()"
end

#loaded_count ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 92

def loaded_count
  @loaded_objects.size
end

#missing_mandatory(mandatory_list) ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 79

def missing_mandatory( mandatory_list )
  [mandatory_list - @headers].flatten
end

#new_load_object ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 83

def new_load_object
  @load_object = @load_object_class.new
  @load_object
end

#process(method_detail, value) ⇒ Object

What process a value string from a column. Assigning value(s) to correct association on @load_object. Method detail represents a column from a file and it's correlated AR associations. Value string which may contain multiple values for a collection association.



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# File 'lib/loaders/loader_base.rb', line 125

def process(method_detail, value)
  #puts "INFO: LOADER BASE processing #{@load_object}"
  @current_value = value
  @current_method_detail = method_detail

  if(method_detail.operator_for(:has_many))

    if(method_detail.operator_class && @current_value)

      # there are times when we need to save early, for example before assigning to
      # has_and_belongs_to associations which require the load_object has an id for the join table
    
      save if( load_object.valid? && load_object.new_record? )

      # A single column can contain multiple associations delimited by special char
      columns = @current_value.split(@@multi_assoc_delim)

      # Size:large|Colour:red,green,blue   => generates find_by_size( 'large' ) and find_all_by_colour( ['red','green','blue'] )

      columns.each do |assoc|
        operator, values = assoc.split(@@name_value_delim)

        lookups = values.split(@@multi_value_delim)

        if(lookups.size > 1)

          @current_value = method_detail.operator_class.send("find_all_by_#{operator}", lookups )

          unless(lookups.size == @current_value.size)
            found = @current_value.collect {|f| f.send(operator) }
            @load_object.errors.add( method_detail.operator, "Association with key(s) #{(lookups - found).inspect} NOT found")
            puts "WARNING: Association with key(s) #{(lookups - found).inspect} NOT found - Not added."
            next if(@current_value.empty?)
          end

        else

          @current_value = method_detail.operator_class.send("find_by_#{operator}", lookups )

          unless(@current_value)
            @load_object.errors.add( method_detail.operator, "Association with key #{lookups} NOT found")
            puts "WARNING: Association with key #{lookups} NOT found - Not added."
            next
          end

        end

        # Lookup Assoc's Model done, now add the found value(s) to load model's collection
        method_detail.assign(@load_object, @current_value)
      end
    end
    # END HAS_MANY
  else
    # Nice n simple straight assignment to a column variable
    method_detail.assign(@load_object, @current_value)
  end
end

#reset(object = nil) ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 68

def reset(object = nil)
  @load_object = object || new_load_object
  @loaded_objects, @failed_objects = [],[]
  @current_value = nil
end

#save ⇒ Object 



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# File 'lib/loaders/loader_base.rb', line 183

def save
  puts "SAVING #{load_object.class} : #{load_object.inspect}" #if(options[:verbose])
  begin
    @load_object.save
    @loaded_objects << load_object unless(@loaded_objects.include?(load_object))
  rescue => e
    @failed_objects << load_object unless(@failed_objects.include?(load_object))
    puts "Error saving #{load_object.class} : #{e.inspect}"
    raise "Error in save whilst processing column #{@current_method_detail.name}" if(@options[:strict])
  end
end