Class: ForestLiana::FiltersParser

Inherits:
Object
  • Object
show all
Defined in:
app/services/forest_liana/filters_parser.rb

Constant Summary collapse

AGGREGATOR_OPERATOR = 
%w(and or)

Instance Method Summary collapse

Constructor Details

#initialize(filters, resource, timezone) ⇒ FiltersParser

Returns a new instance of FiltersParser.



5
6
7
8
9
10
11
12
13
14
15
 
# File 'app/services/forest_liana/filters_parser.rb', line 5

def initialize(filters, resource, timezone)
  begin
    @filters = JSON.parse(filters)
  rescue JSON::ParserError
    raise ForestLiana::Errors::HTTP422Error.new('Invalid filters JSON format')
  end

  @resource = resource
  @operator_date_parser = OperatorDateIntervalParser.new(timezone)
  @joins = []
end

Instance Method Details

#apply_filters ⇒ Object 



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
 
# File 'app/services/forest_liana/filters_parser.rb', line 17

def apply_filters
  return @resource unless @filters

  where = parse_aggregation(@filters)
  return @resource unless where

  @joins.each do |join|
    current_resource = @resource.reflect_on_association(join.name).klass
    current_resource.include(ArelHelpers::Aliases)
    current_resource.aliased_as(join.name) do |aliased_resource|
      @resource = @resource.joins(ArelHelpers.join_association(@resource, join.name, Arel::Nodes::OuterJoin, aliases: [aliased_resource]))
    end
  end

  @resource.where(where)
end

#apply_filters_on_previous_interval(previous_condition) ⇒ Object 



242
243
244
245
246
247
 
# File 'app/services/forest_liana/filters_parser.rb', line 242

def apply_filters_on_previous_interval(previous_condition)
  # Ressource should have already been joined
  where = parse_aggregation_on_previous_interval(@filters, previous_condition)

  @resource.where(where)
end

#ensure_valid_aggregation(node) ⇒ Object

Raises:

  • (ForestLiana::Errors::HTTP422Error) 


287
288
289
290
 
# File 'app/services/forest_liana/filters_parser.rb', line 287

def ensure_valid_aggregation(node)
  raise ForestLiana::Errors::HTTP422Error.new('Filters cannot be a raw value') unless node.is_a?(Hash)
  raise_empty_condition_in_filter_error if node.empty?
end

#ensure_valid_condition(condition) ⇒ Object

Raises:

  • (ForestLiana::Errors::HTTP422Error) 


292
293
294
295
296
297
298
 
# File 'app/services/forest_liana/filters_parser.rb', line 292

def ensure_valid_condition(condition)
  raise_empty_condition_in_filter_error if condition.empty?
  raise ForestLiana::Errors::HTTP422Error.new('Condition cannot be a raw value') unless condition.is_a?(Hash)
  unless condition['field'].is_a?(String) and condition['operator'].is_a?(String)
    raise ForestLiana::Errors::HTTP422Error.new('Invalid condition format')
  end
end

#get_association_field_and_resource(field_name) ⇒ Object 



70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
 
# File 'app/services/forest_liana/filters_parser.rb', line 70

def get_association_field_and_resource(field_name)
  if is_belongs_to(field_name)
    association = field_name.partition(':').first.to_sym
    association_field = field_name.partition(':').last

    unless @resource.reflect_on_association(association)
      raise ForestLiana::Errors::HTTP422Error.new("Association '#{association}' not found")
    end

    current_resource = @resource.reflect_on_association(association).klass

    return association_field, current_resource
  else
    return field_name, @resource
  end
end

#get_association_name_for_condition(field) ⇒ Object 



202
203
204
205
206
207
208
209
210
211
 
# File 'app/services/forest_liana/filters_parser.rb', line 202

def get_association_name_for_condition(field)
  field, subfield = field.split(':')

  association = @resource.reflect_on_association(field.to_sym)
  return nil if association.blank?

  @joins << association unless @joins.include? association

  association.name
end

#get_previous_interval_condition ⇒ Object

NOTICE: Look for a previous interval condition matching the following:

- If the filter is a simple condition at the root the check is done right away.
- There can't be a previous interval condition if the aggregator is 'or' (no meaning).
- The condition's operator has to be elligible for a previous interval.
- There can't be two previous interval condition.



218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
 
# File 'app/services/forest_liana/filters_parser.rb', line 218

def get_previous_interval_condition
  current_previous_interval = nil
  # NOTICE: Leaf condition at root
  unless @filters['aggregator']
    return @filters if @operator_date_parser.has_previous_interval?(@filters['operator'])
  end

  if @filters['aggregator'] === 'and'
    @filters['conditions'].each do |condition|
      # NOTICE: Nested conditions
      return nil if condition['aggregator']

      if @operator_date_parser.has_previous_interval?(condition['operator'])
        # NOTICE: There can't be two previous_interval.
        return nil if current_previous_interval

        current_previous_interval = condition
      end
    end
  end

  current_previous_interval
end

#is_belongs_to(field) ⇒ Object 



198
199
200
 
# File 'app/services/forest_liana/filters_parser.rb', line 198

def is_belongs_to(field)
  field.include?(':')
end

#parse_aggregation(node) ⇒ Object 



34
35
36
37
38
39
40
41
42
43
44
45
46
47
 
# File 'app/services/forest_liana/filters_parser.rb', line 34

def parse_aggregation(node)
  ensure_valid_aggregation(node)

  return parse_condition(node) unless node['aggregator']

  conditions = []
  node['conditions'].each do |condition|
    conditions.push(parse_aggregation(condition))
  end

  operator = parse_aggregation_operator(node['aggregator'])

  conditions.empty? ? nil : "(#{conditions.join(" #{operator} ")})"
end

#parse_aggregation_on_previous_interval(node, previous_condition) ⇒ Object 



249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
 
# File 'app/services/forest_liana/filters_parser.rb', line 249

def parse_aggregation_on_previous_interval(node, previous_condition)
  raise_empty_condition_in_filter_error unless node

  return parse_previous_interval_condition(node) unless node['aggregator']

  conditions = []
  node['conditions'].each do |condition|
    if condition == previous_condition
      conditions.push(parse_previous_interval_condition(condition))
    else
      conditions.push(parse_aggregation(condition))
    end
  end

  operator = parse_aggregation_operator(node['aggregator'])

  conditions.empty? ? nil : "(#{conditions.join(" #{operator} ")})"
end

#parse_aggregation_operator(aggregator_operator) ⇒ Object 



124
125
126
127
128
129
130
 
# File 'app/services/forest_liana/filters_parser.rb', line 124

def parse_aggregation_operator(aggregator_operator)
  unless AGGREGATOR_OPERATOR.include?(aggregator_operator)
    raise_unknown_operator_error(aggregator_operator)
  end

  aggregator_operator.upcase
end

#parse_condition(condition) ⇒ Object 



49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
 
# File 'app/services/forest_liana/filters_parser.rb', line 49

def parse_condition(condition)
  where = parse_condition_without_smart_field(condition)

  field_name = condition['field']

  if ForestLiana::SchemaHelper.is_smart_field?(@resource, field_name)
    schema = ForestLiana.schema_for_resource(@resource)
    field_schema = schema.fields.find do |field|
      field[:field].to_s == field_name
    end

    unless field_schema.try(:[], :filter)
      raise ForestLiana::Errors::NotImplementedMethodError.new("method filter on smart field '#{field_name}' not found")
    end

    return field_schema[:filter].call(condition, where)
  end

  where
end

#parse_condition_without_smart_field(condition) ⇒ Object 



87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
 
# File 'app/services/forest_liana/filters_parser.rb', line 87

def parse_condition_without_smart_field(condition)
  ensure_valid_condition(condition)

  operator = condition['operator']
  value = condition['value']
  field_name = condition['field']

  if @operator_date_parser.is_date_operator?(operator)
    condition = @operator_date_parser.get_date_filter(operator, value)
    return "#{parse_field_name(field_name)} #{condition}"
  end

  association_field, current_resource = get_association_field_and_resource(field_name)

  # NOTICE: Set the integer value instead of a string if "enum" type
  # NOTICE: Rails 3 do not have a defined_enums method
  if current_resource.respond_to?(:defined_enums) && current_resource.defined_enums.has_key?(association_field)
    value = current_resource.defined_enums[association_field][value]
  end

  parsed_field = parse_field_name(field_name)
  parsed_operator = parse_operator(operator)
  parsed_value = parse_value(operator, value)
  field_and_operator = "#{parsed_field} #{parsed_operator}"

  # parenthesis around the parsed_value are required to make the `IN` operator work
  # and have no side effects on other requests
  if Rails::VERSION::MAJOR < 5
    "#{field_and_operator} (#{ActiveRecord::Base.sanitize(parsed_value)})"
  # NOTICE: sanitize method as been removed in Rails 5.1 and sanitize_sql introduced in Rails 5.2.
  elsif Rails::VERSION::MAJOR == 5 && Rails::VERSION::MINOR == 1
    "#{field_and_operator} (#{ActiveRecord::Base.connection.quote(parsed_value)})"
  else
    ActiveRecord::Base.sanitize_sql(["#{field_and_operator} (?)", parsed_value])
  end
end

#parse_field_name(field) ⇒ Object 



175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
 
# File 'app/services/forest_liana/filters_parser.rb', line 175

def parse_field_name(field)
  if is_belongs_to(field)
    current_resource = @resource.reflect_on_association(field.split(':').first.to_sym)&.klass
    raise ForestLiana::Errors::HTTP422Error.new("Field '#{field}' not found") unless current_resource

    association = get_association_name_for_condition(field)
    quoted_table_name = ActiveRecord::Base.connection.quote_column_name(association)
    field_name = field.split(':')[1]
  else
    quoted_table_name = @resource.quoted_table_name
    current_resource = @resource
    field_name = field
  end
  quoted_field_name = ActiveRecord::Base.connection.quote_column_name(field_name)

  column_found = current_resource.columns.find { |column| column.name == field.split(':').last }
  if column_found.nil? && !ForestLiana::SchemaHelper.is_smart_field?(current_resource, field_name)
    raise ForestLiana::Errors::HTTP422Error.new("Field '#{field}' not found")
  end

  "#{quoted_table_name}.#{quoted_field_name}"
end

#parse_operator(operator) ⇒ Object 



132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
 
# File 'app/services/forest_liana/filters_parser.rb', line 132

def parse_operator(operator)
  case operator
  when 'not'
    'NOT'
  when 'greater_than', 'after'
    '>'
  when 'less_than', 'before'
    '<'
  when 'contains', 'starts_with', 'ends_with'
    'LIKE'
  when 'not_contains'
    'NOT LIKE'
  when 'not_equal'
    '!='
  when 'equal'
    '='
  when 'blank'
    'IS'
  when 'present'
    'IS NOT'
  when 'in'
    'IN'
  else
    raise_unknown_operator_error(operator)
  end
end

#parse_previous_interval_condition(condition) ⇒ Object 



268
269
270
271
272
273
274
275
276
277
 
# File 'app/services/forest_liana/filters_parser.rb', line 268

def parse_previous_interval_condition(condition)
  raise_empty_condition_in_filter_error unless condition

  parsed_condition = @operator_date_parser.get_date_filter_for_previous_interval(
    condition['operator'],
    condition['value']
  )

  "#{parse_field_name(condition['field'])} #{parsed_condition}"
end

#parse_value(operator, value) ⇒ Object 



159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
 
# File 'app/services/forest_liana/filters_parser.rb', line 159

def parse_value(operator, value)
  case operator
  when 'not', 'greater_than', 'less_than', 'not_equal', 'equal', 'before', 'after', 'in'
    value
  when 'contains', 'not_contains'
    "%#{value}%"
  when 'starts_with'
    "#{value}%"
  when 'ends_with'
    "%#{value}"
  when 'present', 'blank'
  else
    raise_unknown_operator_error(operator)
  end
end

#raise_empty_condition_in_filter_error ⇒ Object

Raises:

  • (ForestLiana::Errors::HTTP422Error) 


283
284
285
 
# File 'app/services/forest_liana/filters_parser.rb', line 283

def raise_empty_condition_in_filter_error
  raise ForestLiana::Errors::HTTP422Error.new('Empty condition in filter')
end

#raise_unknown_operator_error(operator) ⇒ Object

Raises:

  • (ForestLiana::Errors::HTTP422Error) 


279
280
281
 
# File 'app/services/forest_liana/filters_parser.rb', line 279

def raise_unknown_operator_error(operator)
  raise ForestLiana::Errors::HTTP422Error.new("Unknown provided operator '#{operator}'")
end