Module: DataMapper::Persevere::Query

Defined in:
lib/persevere_adapter/query.rb

Instance Method Summary collapse

Instance Method Details

#json_query_headers ⇒ Object

The headers of a json query

Author:

  • lamb



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# File 'lib/persevere_adapter/query.rb', line 195

def json_query_headers
  headers = Hash.new
  offset = self.offset.to_i
  limit = self.limit.nil? ? nil : self.limit.to_i + offset - 1

  if offset != 0 || !limit.nil?
    headers.merge!( {"Range" => "items=#{offset}-#{limit}"} )
  end
  return headers
end

#munge_condition(condition) ⇒ Object

TODO: Clean this mess up.

Author:

  • lamb



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# File 'lib/persevere_adapter/query.rb', line 8

def munge_condition(condition)
  loaded_value = condition.loaded_value
  return_value = ""
  subject = condition.subject 
  
  if subject.is_a?(DataMapper::Property)
    rhs = case loaded_value
    when String               then "\"#{loaded_value}\""
    when DateTime             then "date(%10.f)" % (Time.parse(loaded_value.to_s).to_f * 1000)
    when nil                  then "undefined"
    else                           loaded_value
    end
    return_value = "#{condition.subject.field}#{condition.__send__(:comparator_string)}#{rhs}"
  elsif subject.is_a?(DataMapper::Associations::ManyToOne::Relationship)
    # Join relationship, bury it down!
    if self.model != subject.child_model
      my_side_of_join = links.select{|relation| 
        relation.kind_of?(DataMapper::Associations::ManyToOne::Relationship) &&
        relation.child_model == subject.child_model &&
        # I would really like this to not look at the name, 
        # but sometimes they are different object of the same model
        relation.parent_model.name == self.model.name }.first
        
      # join_results = subject.child_model.all(subject.field.to_sym => loaded_value)
      join_results = subject.child_model.all(subject.child_key.first.name => loaded_value[subject.parent_key.first.name])
      
      return_value = join_results.map{|r| "#{self.model.key.first.name}=#{r[my_side_of_join.child_key.first.name]}"}.join('|')
    else
      comparator = loaded_value.nil? ? 'undefined' : loaded_value.key.first
      return_value = "#{subject.child_key.first.name}#{condition.__send__(:comparator_string)}#{comparator}"
    end
  elsif subject.is_a?(DataMapper::Associations::Relationship)
    if self.model != subject.child_model
      return_value = "#{subject.child_key.first.name}#{condition.__send__(:comparator_string)}#{loaded_value.key.first}"
    else
      comparator = loaded_value.nil? ? 'undefined' : loaded_value.key.first
      return_value = "#{subject.field}_id#{condition.__send__(:comparator_string)}#{comparator}"
    end
  end
  return_value
end

#process_condition(condition) ⇒ Object 



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# File 'lib/persevere_adapter/query.rb', line 51

def process_condition(condition)
  case condition
    # Persevere 1.0 regular expressions are disable for security so we pass them back for DataMapper query filtering
    # without regular expressions, the like operator is inordinately challenging hence we pass it back
    # when :regexp then "RegExp(\"#{condition.value.source}\").test(#{condition.subject.name})"
  when DataMapper::Query::Conditions::RegexpComparison then []
  when DataMapper::Query::Conditions::LikeComparison then "#{condition.subject.field}='#{condition.loaded_value.gsub('%', '*')}'"
  when DataMapper::Query::Conditions::AndOperation then 
    inside = condition.operands.map { |op| process_condition(op) }.flatten
    inside.empty? ? []  : "(#{inside.join("&")})"
  when DataMapper::Query::Conditions::OrOperation then "(#{condition.operands.map { |op| process_condition(op) }.join("|")})"
  when DataMapper::Query::Conditions::NotOperation then 
    inside = process_condition(condition.operand) 
    inside.empty? ? [] : "!(%s)" % inside
  when DataMapper::Query::Conditions::InclusionComparison then 
    result_string = Array.new
    condition.value.to_a.each do |candidate|
      if condition.subject.is_a?(DataMapper::Associations::Relationship)
        result_string << "#{condition.subject.child_key.first.name}=#{candidate.key.first}" #munge_condition(condition)
      else
        result_string << "#{condition.subject.name}=#{candidate}"
      end
    end
    if result_string.length > 0
      "(#{result_string.join("|")})"
    else
      "#{condition.subject.name}=''"
    end
  when DataMapper::Query::Conditions::EqualToComparison,
    DataMapper::Query::Conditions::GreaterThanComparison,
    DataMapper::Query::Conditions::LessThanComparison, 
    DataMapper::Query::Conditions::GreaterThanOrEqualToComparison,
    DataMapper::Query::Conditions::LessThanOrEqualToComparison then
    munge_condition(condition)
  when DataMapper::Query::Conditions::NullOperation then []
  when Array then
    old_statement, bind_values = condition
    statement = old_statement.dup
    bind_values.each{ |bind_value| statement.sub!('?', bind_value.to_s) }
    statement.gsub(' ', '')
  else condition.to_s.gsub(' ', '')
  end
end

#to_json_query ⇒ Object

Convert a DataMapper Query to a JSON Query.

Parameters:

  • query (Query) —

    The DataMapper query object passed in



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# File 'lib/persevere_adapter/query.rb', line 102

def to_json_query      
  # Body of main function

  json_query = ''
  field_ops = Array.new
  outfields = Array.new
  
  json_query += self.to_json_query_filter

  self.fields.each do |field|
    if field.respond_to?(:operator)
      field_ops << case field.operator
      when :count then
        if field.target.is_a?(DataMapper::Property)
          "[?#{field.target.field}!=undefined].length"
        else # field.target is all.
          ".length"
        end
      when :min
        if field.target.kind_of?(DataMapper::Property::DateTime) || 
          field.target.kind_of?(DataMapper::Property::Time) || 
          field.target.kind_of?(DataMapper::Property::Date)
          "[=#{field.target.field}]"
        else
          ".min(?#{field.target.field})"
        end
      when :max
        if field.target.kind_of?(DataMapper::Property::DateTime) || 
          field.target.kind_of?(DataMapper::Property::Time) || 
          field.target.kind_of?(DataMapper::Property::Date)
          "[=#{field.target.field}]"
        else
          ".max(?#{field.target.field})"
        end
      when :sum
        ".sum(?#{field.target.field})"
      when :avg
        "[=#{field.target.field}]"
      end
    else
      outfields << "'#{field.field}':#{field.field}"
    end
  end

  json_query += field_ops.join("")

  json_query += self.to_json_query_ordering

  json_query += "[={" + outfields.join(',') + "}]" unless outfields.empty?


  # puts json_query, headers
  return json_query, self.json_query_headers
end

#to_json_query_filter ⇒ Object

The filter portion on a json query

Author:

  • lamb



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# File 'lib/persevere_adapter/query.rb', line 161

def to_json_query_filter
  query_terms = []
  query_terms << process_condition(conditions) 

  if query_terms.flatten.length != 0
    return "[?#{query_terms.join("][?")}]"
  else
    return ''
  end
  
end

#to_json_query_ordering ⇒ Object

The ordering portion of a json query

Author:

  • lamb



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# File 'lib/persevere_adapter/query.rb', line 177

def to_json_query_ordering
  order_operations = []
  if order && order.any?
    order.map do |direction|
      order_operations << case direction.operator
      when :asc then "[\/#{direction.target.field}]"
      when :desc then "[\\#{direction.target.field}]"
      end
    end
  end

  order_operations.join("")
end