Class: Lockstep::Query

Inherits:
Object
  • Object
show all
Defined in:
app/concepts/lockstep/query.rb

Constant Summary collapse

PREDICATES = 
{
  _not_eq: "NE",
  _eq: "EQ",
  _gteq: "GE",
  _gt: "GT",
  _lteq: "LE",
  _lt: "LT",
  _in: "IN",
  _contains: "CONTAINS",
  _starts_with: "STARTSWITH",
  _ends_with: "ENDSWITH",
  _is: "IS",
}.with_indifferent_access

Instance Method Summary collapse

Constructor Details

#initialize(klass) ⇒ Query

Returns a new instance of Query.



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# File 'app/concepts/lockstep/query.rb', line 2

def initialize(klass)
  @klass = klass
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(meth, *args, &block) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 335

def method_missing(meth, *args, &block)
  method_name = method_name.to_s
  if method_name.start_with?("find_by_")
    attrib = method_name.gsub(/^find_by_/, "")
    finder_name = "find_all_by_#{attrib}"

    define_singleton_method(finder_name) do |target_value|
      where({ attrib.to_sym => target_value }).first
    end

    send(finder_name, args[0])
  elsif method_name.start_with?("find_all_by_")
    attrib = method_name.gsub(/^find_all_by_/, "")
    finder_name = "find_all_by_#{attrib}"

    define_singleton_method(finder_name) do |target_value|
      where({ attrib.to_sym => target_value }).all
    end

    send(finder_name, args[0])
  end

  if @klass.scopes[meth].present?
    instance_exec *args, &@klass.scopes[meth]
  elsif Array.method_defined?(meth)
    all.send(meth, *args, &block)
  else
    super
  end
end

Instance Method Details

#all ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 315

def all
  execute
end

#build_filter ⇒ Object

def related_to(obj, key)

query = { "$relatedTo" => { "object" => obj.to_pointer, "key" => key } }
criteria[:conditions].merge!(query)
clone

end



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# File 'app/concepts/lockstep/query.rb', line 126

def build_filter
  filter = ""
  criteria[:conditions].each do |condition|
    if condition.is_a?(Hash)
      if condition[:type] == "or"
        filter = build_filter_condition(filter, "OR", condition[:query].build_filter)
      else
        condition.each do |key, value|
          filter = build_filter_condition(filter, "AND", build_filter_query(key, value))
        end
      end
    elsif condition.is_a?(String)
      filter = build_filter_condition(filter, "AND", condition)
    end
  end
  filter
end

#build_filter_condition(filter, merge_predicate, condition) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 144

def build_filter_condition(filter, merge_predicate, condition)
  if filter.present?
    filter = "(#{filter}) #{merge_predicate} (#{condition})"
  else
    filter += condition
  end
  filter
end

#build_filter_query(key, value) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 167

def build_filter_query(key, value)
  key = key.to_s unless key.is_a?(String)
  predicate = "eq" # default
  PREDICATES.each do |k, p|
    if key.ends_with?(k)
      key = key.gsub(k, "")
      predicate = p
      break
    end
  end

  # Build value
  if value.is_a?(Array)
    value = "(#{value.map { |v| v.is_a?(String) ? "'#{v}'" : v }.join(",")})"
    predicate = "in" if predicate == "eq"
  elsif value.is_a?(String) and !["NULL", "NOT NULL"].include?(value)
    value = "'#{value}'"
  elsif value.nil?
    predicate = "IS" if predicate == "eq"
    value = "NULL"
  end

  "#{key.camelize(:lower)} #{predicate} #{value}"
end

#build_params ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 192

def build_params
  params = {}
  params.merge!({ :filter => build_filter }) if criteria[:conditions]
  # Lockstep Platform API does not support a page size of 1
  params.merge!({ :pageSize => (criteria[:limit] == 1 ? 2 : criteria[:limit]) }) if criteria[:limit]
  params.merge!({ :pageNumber => criteria[:page_number] }) if criteria[:page_number]
  params.merge!({ :include => criteria[:include].join(",") }) if criteria[:include]
  params.merge!({ :order => criteria[:order].join(",") }) if criteria[:order]
  params.merge!({ :pageSize => 2 }) if criteria[:count]
  params.reject! { |k, v| v.blank? }
  params
end

#chunk(count = 100) ⇒ Object

Divides the query into multiple chunks if you’re running into RestClient::BadRequest errors.



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# File 'app/concepts/lockstep/query.rb', line 114

def chunk(count = 100)
  with_clone do
    criteria[:chunk] = count
  end
end

#chunk_results(params = {}) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 288

def chunk_results(params = {})
  page = criteria[:page] || 0
  limit = criteria[:limit] || 0
  # completed = false
  records = []
  loop do
    params[:pageNumber] = page
    params[:pageSize] = limit > 0 ? [limit - records.size, criteria[:chunk]].min : criteria[:chunk]
    break if params[:pageSize] == 0

    results = get_results(params)
    break unless results.present?

    records += results
    break if limit > 0 and records.size >= limit

    page += 1
  end

  records
end

#clone ⇒ Object

Clone is used as return object as it messes with the OR query in situations like these

unscoped = Lockstep::Connection.unscoped
unscoped.where(a: 1).or(unscoped.where(b: 1))
both the where conditions in the above scenario is modifying the same object causing stack-overflow



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# File 'app/concepts/lockstep/query.rb', line 14

def clone
  c = Lockstep::Query.new(@klass)
  c.criteria.deep_merge!(self.criteria.deep_dup)
  c
end

#convert_arg(arg) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 54

def convert_arg(arg)
  return arg.to_pointer if arg.is_a?(Lockstep::ApiRecord)
  return Lockstep::ApiRecord.to_date_object(arg) if arg.is_a?(Time) || arg.is_a?(Date)
  if arg.is_a?(Hash)
    arg.keys.each do |key|
      @klass.valid_attribute?(key, raise_exception: true)
    end
    return arg.update(arg) { |key, inner_arg| convert_arg(inner_arg) }
  end

  arg
end

#count ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 319

def count
  criteria[:count] = true
  execute
end

#criteria ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 26

def criteria
  @criteria ||= { :conditions => [] }
end

#execute ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 205

def execute
  return [] if criteria[:none]
  # This code automatically adds all related objects
  #
  # if @klass.has_many_relations
  #   relations = @klass.has_many_relations.select {|k, val| val[:included]}.keys.map { |relation| relation.to_s }
  #   include_object(*relations)
  # end

  params = build_params

  return chunk_results(params) if criteria[:chunk]

  get_results(params)
end

#find(id) ⇒ Lockstep::ApiRecord

Find a Lockstep::ApiRecord object by ID

Parameters:

  • id (String) —

    the ID of the Parse object you want to find.

Returns:

Raises:



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# File 'app/concepts/lockstep/query.rb', line 328

def find(id)
  raise Lockstep::Exceptions::RecordNotFound, "Couldn't find #{name} without an ID" if id.blank?
  record = where(@klass.id_ref => id).first
  raise Lockstep::Exceptions::RecordNotFound, "Couldn't find #{name} with id: #{id}" if record.blank?
  record
end

#first ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 310

def first
  limit(1)
  execute.first
end

#get_relation_objects(objects) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 246

def get_relation_objects(objects)
  return objects if criteria[:include].blank?

  included_objects = criteria[:include].map { |item| item.to_s.downcase }

  if @klass.has_many_relations
    objects.each do |item|
      @klass.has_many_relations.each do |relation, relation_config|
        next unless included_objects.include?(relation.to_s.downcase)

        if !item.attributes.has_key?(relation.to_s)
          item.attributes[relation.to_s] = Lockstep::RelationArray.new(@klass, [], relation, relation_config[:class_name])
        elsif !item.attributes[relation].is_a?(Lockstep::RelationArray)
          item.attributes[relation.to_s] = Lockstep::RelationArray.new(@klass, item.attributes[relation], relation, relation_config[:class_name])
        end
      end
    end
  end

  objects.each do |item|
    item.attributes.each do |key, value|
      if value.is_a?(Array)
        relation = @klass.has_many_relations[key]
        next if relation.blank? or !included_objects.include?(key.to_s.downcase)

        value.each do |relation_hash|
          relation_obj = turn_relation_hash_into_object(relation, relation_hash)
          value[value.index(relation_hash)] = relation_obj
        end
      elsif value.is_a?(Hash)
        relation = @klass.belongs_to_relations[key]
        next if relation.blank?

        relation_hash = value
        relation_obj = turn_relation_hash_into_object(relation, relation_hash)
        item.attributes[key] = relation_obj
      end
    end
  end
  objects
end

#get_results(params = {}) ⇒ Object

Raises:

  • (StandardError) 


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# File 'app/concepts/lockstep/query.rb', line 221

def get_results(params = {})
  resp = @klass.resource.get(@klass.query_path, :params => params)

  return [] if %w(404).include?(resp.code.to_s)
  # TODO handle non 200 response code. Throwing an exception for now
  raise StandardError.new("#{resp.code} error while fetching: #{resp.body}") unless %w(201 200).include?(resp.code.to_s)

  parsed_response = JSON.parse(resp.body)

  if criteria[:count]
    raise StandardError.new("Count is not supported for #{@klass}") if parsed_response.is_a?(Array)

    results = parsed_response["totalCount"]
    return results.to_i
  else
    results = parsed_response.is_a?(Array) ? parsed_response : parsed_response["records"]
    results = results[0..(criteria[:limit] - 1)] if criteria[:limit]
    get_relation_objects results.map { |r|
      # Convert camelcase to snake-case
      r = r.transform_keys { |key| key.underscore }
      @klass.model_name.to_s.constantize.new(r, false)
    }
  end
end

#include_object(*objects) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 81

def include_object(*objects)
  with_clone do
    criteria[:include] ||= []
    criteria[:include] += objects
    criteria[:include].uniq!
  end
end

#limit(limit) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 67

def limit(limit)
  with_clone do
    # If > 1000, set chunking, because large queries over 1000 need it with Parse
    # criteria[:chunk] = 1000 if limit > 1000
    criteria[:limit] = limit
  end
end

#model ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 6

def model
  @klass
end

#none ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 36

def none
  with_clone do
    criteria[:none] = true
  end
end

#or(query) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 30

def or(query)
  with_clone do
    criteria[:conditions] << { type: "or", query: query }
  end
end

#order(*attr) ⇒ Object

attr: :desc



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# File 'app/concepts/lockstep/query.rb', line 90

def order(*attr)
  with_clone do
    criteria[:order] ||= []
    attr.each do |item|
      if item.is_a?(Hash)
        item.each do |k, v|
          criteria[:order] << "#{k.to_s.camelize.upcase} #{v}"
        end
      elsif item.is_a?(String)
        criteria[:order] << item
      end
    end
  end
end

#page(page_number) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 75

def page(page_number)
  with_clone do
    criteria[:page_number] = page_number
  end
end

#reorder(attr) ⇒ Object

attr: :desc



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# File 'app/concepts/lockstep/query.rb', line 106

def reorder(attr)
  with_clone do
    criteria[:order] = []
    order(attr)
  end
end

#respond_to?(meth) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/concepts/lockstep/query.rb', line 366

def respond_to?(meth)
  if Array.method_defined?(meth)
    true
  else
    super
  end
end

#unscoped ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 374

def unscoped
  Lockstep::Query.new(@klass)
end

#where(args) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 42

def where(args)
  if args.is_a?(Hash)
    args.each do |k, v|
      return none if v.is_a?(Array) and v.blank?
    end
  end

  with_clone do
    criteria[:conditions] << convert_arg(args)
  end
end

#with_clone(&block) ⇒ Object 



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# File 'app/concepts/lockstep/query.rb', line 20

def with_clone(&block)
  c = clone
  c.instance_exec(&block)
  c
end