class PatternQueryHelper::Filtering

Public Class Methods

create_filters(filters:, valid_columns_map: nil, symbol_prefix: "", include_where: true) click to toggle source
# File lib/pattern_query_helper/filtering.rb, line 3
def self.create_filters(filters:, valid_columns_map: nil, symbol_prefix: "", include_where: true)
  filters ||= {}
  all_conditions = []
  filter_params = {}
  filter_array = []
  filters.each do |filter_attribute, criteria|
    if valid_columns_map
      raise ArgumentError.new("Invalid filter '#{filter_attribute}'") unless valid_columns_map[filter_attribute]
      filter_column = valid_columns_map[filter_attribute]
    else
      filter_column = filter_attribute
    end
    criteria.each do |operator_code, criterion|
      filter_symbol = "#{symbol_prefix}#{filter_attribute}_#{operator_code}"
      case operator_code
        when "gte"
          operator = ">="
        when "lte"
          operator = "<="
        when "gt"
          operator = ">"
        when "lt"
          operator = "<"
        when "eql"
          operator = "="
        when "noteql"
          operator = "!="
        when "like"
          modified_filter_column = "lower(#{filter_column})"
          operator = "like"
          criterion.downcase!
        when "in"
          operator = "in (:#{filter_symbol})"
          # if criterion are anything but numbers, downcase the filter_column
          if criterion.scan(/[^\d|,|\s]/).any?
            modified_filter_column = "lower(#{filter_column})"
          end
          criterion = criterion.downcase.split(",")
          filter_symbol_already_embedded = true
        when "notin"
          operator = "not in (:#{filter_symbol})"
          # if criterion are anything but numbers, downcase the filter_column
          if criterion.scan(/[^\d|,|\s]/).any?
            modified_filter_column = "lower(#{filter_column})"
          end
          criterion = criterion.downcase.split(",")
          filter_symbol_already_embedded = true
        when "null"
          operator = criterion.to_s == "true" ? "is null" : "is not null"
          filter_symbol = ""
        else
          raise ArgumentError.new("Invalid operator code '#{operator_code}' on '#{filter_attribute}' filter")
      end
      filter_column = modified_filter_column || filter_column
      condition = "#{filter_column} #{operator}"
      condition << " :#{filter_symbol}" unless filter_symbol_already_embedded or filter_symbol.blank?
      all_conditions << condition
      filter_params["#{filter_symbol}"] = criterion unless filter_symbol.blank?
      filter_array << {
        column: filter_attribute,
        operator: operator,
        value: criterion,
        symbol: filter_symbol
      }
    end
  end

  if include_where
    filter_string = "where " + all_conditions.join("\n and ") unless all_conditions.empty?
  else
    filter_string = all_conditions.empty? ? "1 = 1" : all_conditions.join("\n and ")
  end

  {
    filter_string: filter_string,
    filter_params: filter_params,
    filter_array: filter_array
  }

end