#105 Allow Procs for dynamic value usage

.gitignore

@@ -10,3 +10,4 @@ test/dummy/storage/
 test/dummy/tmp/
 test/dummy/.byebug_history
 *.gem
+/.idea

README.md

@@ -20,6 +20,7 @@ This gems doing it for you. Just use `attached: true` or `content_type: 'image/p
 * validates number of uploaded files (min/max required)
 * validates aspect ratio (if square, portrait, landscape, is_16_9, ...)
 * custom error messages
+* allow procs for dynamic determination of values
 
 ## Usage
 
@@ -124,6 +125,18 @@ class User < ApplicationRecord
 end
 ```
 
+- Proc Usage:
+
+Procs can be used instead of values in all the above examples. They will be called on every validation.
+```ruby
+class User < ApplicationRecord
+  has_many_attached :proc_files
+
+  validates :proc_files, limit: { max: -> (record) { record.admin? ? 100 : 10 } }
+end
+
+```
+
 ## Internationalization (I18n)
 
 Active Storage Validations uses I18n for error messages. For this, add these keys in your translation file:

lib/active_storage_validations.rb

@@ -2,6 +2,7 @@
 
 require 'active_storage_validations/railtie'
 require 'active_storage_validations/engine'
+require 'active_storage_validations/option_proc_unfolding'
 require 'active_storage_validations/attached_validator'
 require 'active_storage_validations/content_type_validator'
 require 'active_storage_validations/size_validator'

lib/active_storage_validations/aspect_ratio_validator.rb

@@ -4,17 +4,14 @@
 
 module ActiveStorageValidations
   class AspectRatioValidator < ActiveModel::EachValidator # :nodoc
+    include OptionProcUnfolding
+
     AVAILABLE_CHECKS = %i[with].freeze
     PRECISION = 3
 
-    def initialize(options)
-      super(options)
-    end
-
-
     def check_validity!
       return true if AVAILABLE_CHECKS.any? { |argument| options.key?(argument) }
-      raise ArgumentError, 'You must pass "aspect_ratio: :OPTION" option to the validator'
+      raise ArgumentError, 'You must pass :with to the validator'
     end
 
     if Rails.gem_version >= Gem::Version.new('6.0.0')
@@ -55,44 +52,45 @@ def validate_each(record, attribute, _value)
 
 
     def is_valid?(record, attribute, metadata)
+      flat_options = unfold_procs(record, self.options, AVAILABLE_CHECKS)
       if metadata[:width].to_i <= 0 || metadata[:height].to_i <= 0
-        add_error(record, attribute, options[:message].presence || :image_metadata_missing)
+        add_error(record, attribute, :image_metadata_missing, flat_options[:with])
         return false
       end
 
-      case options[:with]
+      case flat_options[:with]
       when :square
         return true if metadata[:width] == metadata[:height]
-        add_error(record, attribute, :aspect_ratio_not_square)
+        add_error(record, attribute, :aspect_ratio_not_square, flat_options[:with])
 
       when :portrait
         return true if metadata[:height] > metadata[:width]
-        add_error(record, attribute, :aspect_ratio_not_portrait)
+        add_error(record, attribute, :aspect_ratio_not_portrait, flat_options[:with])
 
       when :landscape
         return true if metadata[:width] > metadata[:height]
-        add_error(record, attribute, :aspect_ratio_not_landscape)
+        add_error(record, attribute, :aspect_ratio_not_landscape, flat_options[:with])
 
       else
-        if options[:with] =~ /is\_(\d*)\_(\d*)/
+        if flat_options[:with] =~ /is_(\d*)_(\d*)/
           x = $1.to_i
           y = $2.to_i
 
           return true if (x.to_f / y).round(PRECISION) == (metadata[:width].to_f / metadata[:height]).round(PRECISION)
 
           add_error(record, attribute, :aspect_ratio_is_not, "#{x}x#{y}")
         else
-          add_error(record, attribute, :aspect_ratio_unknown)
+          add_error(record, attribute, :aspect_ratio_unknown, flat_options[:with])
         end
       end
       false
     end
 
 
-    def add_error(record, attribute, type, interpolate = options[:with])
-      key = options[:message].presence || type
-      return if record.errors.added?(attribute, key)
-      record.errors.add(attribute, key, aspect_ratio: interpolate)
+    def add_error(record, attribute, default_message, interpolate)
+      message = options[:message].presence || default_message
+      return if record.errors.added?(attribute, message)
+      record.errors.add(attribute, message, aspect_ratio: interpolate)
     end
 
   end

lib/active_storage_validations/content_type_validator.rb

@@ -2,27 +2,33 @@
 
 module ActiveStorageValidations
   class ContentTypeValidator < ActiveModel::EachValidator # :nodoc:
+    include OptionProcUnfolding
+
+    AVAILABLE_CHECKS = %i[with in].freeze
+
     def validate_each(record, attribute, _value)
-      return true if !record.send(attribute).attached? || types.empty?
+      return true unless record.send(attribute).attached?
 
+      types = authorized_types(record)
+      return true if types.empty?
+
       files = Array.wrap(record.send(attribute))
 
-      errors_options = { authorized_types: types_to_human_format }
+      errors_options = { authorized_types: types_to_human_format(types) }
       errors_options[:message] = options[:message] if options[:message].present?
 
       files.each do |file|
-        next if is_valid?(file)
+        next if is_valid?(file, types)
 
         errors_options[:content_type] = content_type(file)
         record.errors.add(attribute, :content_type_invalid, **errors_options)
         break
       end
     end
 
-    def types
-      return @types if defined? @types
-
-      @types = (Array.wrap(options[:with]) + Array.wrap(options[:in])).compact.map do |type|
+    def authorized_types(record)
+      flat_options = unfold_procs(record, self.options, AVAILABLE_CHECKS)
+      (Array.wrap(flat_options[:with]) + Array.wrap(flat_options[:in])).compact.map do |type|
         if type.is_a?(Regexp)
           type
         else
@@ -31,7 +37,7 @@ def types
       end
     end
 
-    def types_to_human_format
+    def types_to_human_format(types)
       types
         .map { |type| type.to_s.split('/').last.upcase }
         .join(', ')
@@ -41,7 +47,7 @@ def content_type(file)
       file.blob.present? && file.blob.content_type
     end
 
-    def is_valid?(file)
+    def is_valid?(file, types)
       file_type = content_type(file)
       types.any? do |type|
         type == file_type || (type.is_a?(Regexp) && type.match?(file_type.to_s))

lib/active_storage_validations/dimension_validator.rb

@@ -4,25 +4,30 @@
 
 module ActiveStorageValidations
   class DimensionValidator < ActiveModel::EachValidator # :nodoc
+    include OptionProcUnfolding
+
     AVAILABLE_CHECKS = %i[width height min max].freeze
 
-    def initialize(options)
+    def process_options(record)
+      flat_options = unfold_procs(record, self.options, AVAILABLE_CHECKS)
+
       [:width, :height].each do |length|
-        if options[length] and options[length].is_a?(Hash)
-          if range = options[length][:in]
+        if flat_options[length] and flat_options[length].is_a?(Hash)
+          if (range = flat_options[length][:in])
             raise ArgumentError, ":in must be a Range" unless range.is_a?(Range)
-            options[length][:min], options[length][:max] = range.min, range.max
+            flat_options[length][:min], flat_options[length][:max] = range.min, range.max
           end
         end
       end
       [:min, :max].each do |dim|
-        if range = options[dim]
+        if (range = flat_options[dim])
           raise ArgumentError, ":#{dim} must be a Range (width..height)" unless range.is_a?(Range)
-          options[:width] = { dim => range.first }
-          options[:height] = { dim => range.last }
+          flat_options[:width] = { dim => range.first }
+          flat_options[:height] = { dim => range.last }
         end
       end
-      super
+
+      flat_options
     end
 
 
@@ -64,51 +69,52 @@ def validate_each(record, attribute, _value)
 
 
     def is_valid?(record, attribute, file_metadata)
+      flat_options = process_options(record)
       # Validation fails unless file metadata contains valid width and height.
       if file_metadata[:width].to_i <= 0 || file_metadata[:height].to_i <= 0
-        add_error(record, attribute, options[:message].presence || :image_metadata_missing)
+        add_error(record, attribute, :image_metadata_missing)
         return false
       end
 
       # Validation based on checks :min and :max (:min, :max has higher priority to :width, :height).
-      if options[:min] || options[:max]
-        if options[:min] && (
-          (options[:width][:min] && file_metadata[:width] < options[:width][:min]) ||
-          (options[:height][:min] && file_metadata[:height] < options[:height][:min])
+      if flat_options[:min] || flat_options[:max]
+        if flat_options[:min] && (
+          (flat_options[:width][:min] && file_metadata[:width] < flat_options[:width][:min]) ||
+          (flat_options[:height][:min] && file_metadata[:height] < flat_options[:height][:min])
           )
-          add_error(record, attribute, options[:message].presence || :"dimension_min_inclusion", width: options[:width][:min], height: options[:height][:min])
+          add_error(record, attribute, :dimension_min_inclusion, width: flat_options[:width][:min], height: flat_options[:height][:min])
           return false
         end
-        if options[:max] && (
-          (options[:width][:max] && file_metadata[:width] > options[:width][:max]) ||
-          (options[:height][:max] && file_metadata[:height] > options[:height][:max])
+        if flat_options[:max] && (
+          (flat_options[:width][:max] && file_metadata[:width] > flat_options[:width][:max]) ||
+          (flat_options[:height][:max] && file_metadata[:height] > flat_options[:height][:max])
           )
-          add_error(record, attribute, options[:message].presence || :"dimension_max_inclusion", width: options[:width][:max], height: options[:height][:max])
+          add_error(record, attribute, :dimension_max_inclusion, width: flat_options[:width][:max], height: flat_options[:height][:max])
           return false
         end
 
       # Validation based on checks :width and :height.
       else
         width_or_height_invalid = false
         [:width, :height].each do |length|
-          next unless options[length]
-          if options[length].is_a?(Hash)
-            if options[length][:in] && (file_metadata[length] < options[length][:min] || file_metadata[length] > options[length][:max])
-              add_error(record, attribute, options[:message].presence || :"dimension_#{length}_inclusion", min: options[length][:min], max: options[length][:max])
+          next unless flat_options[length]
+          if flat_options[length].is_a?(Hash)
+            if flat_options[length][:in] && (file_metadata[length] < flat_options[length][:min] || file_metadata[length] > flat_options[length][:max])
+              add_error(record, attribute, :"dimension_#{length}_inclusion", min: flat_options[length][:min], max: flat_options[length][:max])
               width_or_height_invalid = true
             else
-              if options[length][:min] && file_metadata[length] < options[length][:min]
-                add_error(record, attribute, options[:message].presence || :"dimension_#{length}_greater_than_or_equal_to", length: options[length][:min])
+              if flat_options[length][:min] && file_metadata[length] < flat_options[length][:min]
+                add_error(record, attribute, :"dimension_#{length}_greater_than_or_equal_to", length: flat_options[length][:min])
                 width_or_height_invalid = true
               end
-              if options[length][:max] && file_metadata[length] > options[length][:max]
-                add_error(record, attribute, options[:message].presence || :"dimension_#{length}_less_than_or_equal_to", length: options[length][:max])
+              if flat_options[length][:max] && file_metadata[length] > flat_options[length][:max]
+                add_error(record, attribute, :"dimension_#{length}_less_than_or_equal_to", length: flat_options[length][:max])
                 width_or_height_invalid = true
               end
             end
           else
-            if file_metadata[length] != options[length]
-              add_error(record, attribute, options[:message].presence || :"dimension_#{length}_equal_to", length: options[length])
+            if file_metadata[length] != flat_options[length]
+              add_error(record, attribute, :"dimension_#{length}_equal_to", length: flat_options[length])
               width_or_height_invalid = true
             end
           end
@@ -120,10 +126,10 @@ def is_valid?(record, attribute, file_metadata)
       true # valid file
     end
 
-    def add_error(record, attribute, type, **attrs)
-      key = options[:message].presence || type
-      return if record.errors.added?(attribute, key)
-      record.errors.add(attribute, key, **attrs)
+    def add_error(record, attribute, default_message, **attrs)
+      message = options[:message].presence || default_message
+      return if record.errors.added?(attribute, message)
+      record.errors.add(attribute, message, **attrs)
     end
 
   end

lib/active_storage_validations/limit_validator.rb

@@ -2,31 +2,33 @@
 
 module ActiveStorageValidations
   class LimitValidator < ActiveModel::EachValidator # :nodoc:
+    include OptionProcUnfolding
+
     AVAILABLE_CHECKS = %i[max min].freeze
 
     def check_validity!
       return true if AVAILABLE_CHECKS.any? { |argument| options.key?(argument) }
-
       raise ArgumentError, 'You must pass either :max or :min to the validator'
     end
 
     def validate_each(record, attribute, _)
       return true unless record.send(attribute).attached?
 
       files = Array.wrap(record.send(attribute)).compact.uniq
-      errors_options = { min: options[:min], max: options[:max] }
+      flat_options = unfold_procs(record, self.options, AVAILABLE_CHECKS)
+      errors_options = { min: flat_options[:min], max: flat_options[:max] }
 
-      return true if files_count_valid?(files.count)
+      return true if files_count_valid?(files.count, flat_options)
       record.errors.add(attribute, options[:message].presence || :limit_out_of_range, **errors_options)
     end
 
-    def files_count_valid?(count)
-      if options[:max].present? && options[:min].present?
-        count >= options[:min] && count <= options[:max]
-      elsif options[:max].present?
-        count <= options[:max]
-      elsif options[:min].present?
-        count >= options[:min]
+    def files_count_valid?(count, flat_options)
+      if flat_options[:max].present? && flat_options[:min].present?
+        count >= flat_options[:min] && count <= flat_options[:max]
+      elsif flat_options[:max].present?
+        count <= flat_options[:max]
+      elsif flat_options[:min].present?
+        count >= flat_options[:min]
       end
     end
   end

lib/active_storage_validations/option_proc_unfolding.rb

@@ -0,0 +1,16 @@
+module ActiveStorageValidations
+  module OptionProcUnfolding
+
+    def unfold_procs(record, object, only_keys = nil)
+      case object
+      when Hash
+        object.merge(object) { |key, value| only_keys&.exclude?(key) ? unfold_procs(record, value, []) : unfold_procs(record, value) }
+      when Array
+        object.map { |o| unfold_procs(record, o, only_keys) }
+      else
+        object.is_a?(Proc) ? object.call(record) : object
+      end
+    end
+
+  end
+end