module ActiveScaffold::Constraints

Public Class Methods

included(base) click to toggle source
# File lib/active_scaffold/constraints.rb, line 3
def self.included(base)
  base.helper_method :active_scaffold_constraints
end

Protected Instance Methods

active_scaffold_constraints() click to toggle source

Returns the current constraints

# File lib/active_scaffold/constraints.rb, line 10
def active_scaffold_constraints
  @active_scaffold_constraints ||= active_scaffold_embedded_params[:constraints] || {}
end
apply_constraints_to_record(record, options = {}) click to toggle source

Applies constraints to the given record.

Searches through the known columns for association columns. If the given constraint is an association, it assumes that the constraint value is an id. It then does a association.klass.find with the value and adds the associated object to the record.

For some operations ActiveRecord will automatically update the database. That’s not always ok. If it is ok (e.g. you’re in a transaction), then set :allow_autosave to true.

# File lib/active_scaffold/constraints.rb, line 155
def apply_constraints_to_record(record, options = {})
  options[:allow_autosave] = false if options[:allow_autosave].nil?
  constraints = options[:constraints] || active_scaffold_constraints

  config = record.is_a?(active_scaffold_config.model) ? active_scaffold_config : active_scaffold_config_for(record.class)
  constraints.each do |k, v|
    column = config.columns[k]
    if column&.association
      if column.association.collection?
        record.send(k.to_s).send(:<<, column.association.klass.find(v))
      elsif column.association.polymorphic?
        unless v.is_a?(Array) && v.size >= 2
          raise ActiveScaffold::MalformedConstraint, polymorphic_constraint_error(column.association), caller
        end
        record.send("#{k}=", v[0].constantize.find(v[1])) if v.size == 2
      elsif !column.association.source_reflection&.options&.include?(:through) && # regular singular association, or one-level through association
            !v.is_a?(Array)
        record.send("#{k}=", column.association.klass.find(v))

        # setting the belongs_to side of a has_one isn't safe. if the has_one was already
        # specified, rails won't automatically clear out the previous associated record.
        #
        # note that we can't take the extra step to correct this unless we're permitted to
        # run operations where activerecord auto-saves the object.
        reverse = column.association.reverse_association
        if reverse.singular? && !reverse.belongs_to? && options[:allow_autosave]
          record.send(k).send("#{reverse.name}=", record)
        end
      end
    else
      record.send("#{k}=", v)
    end
  end
end
condition_from_association_constraint(association, value) click to toggle source

We do NOT want to use .search_sql. If anything, search_sql will refer to a human-searchable value on the associated record.

# File lib/active_scaffold/constraints.rb, line 110
def condition_from_association_constraint(association, value)
  # when the reverse association is a :belongs_to, the id for the associated object only exists as
  # the primary_key on the other table. so for :has_one and :has_many (when the reverse is :belongs_to),
  # we have to use the other model's primary_key.
  #
  # please see the relevant tests for concrete examples.

  field =
    if association.belongs_to?
      association.foreign_key
    else
      association.klass.primary_key
    end

  table = association.belongs_to? ? active_scaffold_config.model.table_name : association.table_name
  value = association.klass.find(value).send(association.primary_key) if association.primary_key

  if association.polymorphic?
    unless value.is_a?(Array) && value.size >= 2
      raise ActiveScaffold::MalformedConstraint, polymorphic_constraint_error(association), caller
    end
    condition = {table => {association.foreign_type => value[0], field => value.size == 2 ? value[1] : value[1..-1]}}
  else
    condition = {table => {field.to_s => value}}
  end

  condition
end
conditions_from_constraints() click to toggle source

Returns search conditions based on the current scaffold constraints.

Supports constraints based on either a column name (in which case it checks for an association or just uses the search_sql) or a database field name.

All of this work is primarily to support nested scaffolds in a manner generally useful for other embedded scaffolds.

# File lib/active_scaffold/constraints.rb, line 58
def conditions_from_constraints
  hash_conditions = {}
  conditions = [hash_conditions]
  active_scaffold_constraints.each do |k, v|
    column = active_scaffold_config.columns[k]
    if column
      # Assume this is a multi-level association constraint.
      # example:
      #   data model: Park -> Den -> Bear
      #   constraint: :den => {:park => 5}
      if params_hash? v
        far_association = column.association.klass.reflect_on_association(v.keys.first)
        field = far_association.klass.primary_key
        table = far_association.table_name

        active_scaffold_references.concat([{k => far_association.name}]) # e.g. {:den => :park}
        hash_conditions.deep_merge!(table => {field => v.values.first})

      # association column constraint
      elsif column.association
        join_from_association_constraint(column)
        hash_conditions.deep_merge!(condition_from_association_constraint(column.association, v))

      # regular column constraints
      elsif column.searchable? && params[column.name] != v
        active_scaffold_references.concat column.references if column.includes.present?
        conditions << [column.search_sql.collect { |search_sql| "#{search_sql} = ?" }.join(' OR '), *([v] * column.search_sql.size)]
      end
    # unknown-to-activescaffold-but-real-database-column constraint
    elsif active_scaffold_config._columns_hash[k.to_s] && params[column.name] != v
      hash_conditions.deep_merge!(k => v)
    else
      raise ActiveScaffold::MalformedConstraint, constraint_error(active_scaffold_config.model, k), caller
    end
  end
  conditions.reject(&:blank?)
end
constraint_error(klass, column_name) click to toggle source
# File lib/active_scaffold/constraints.rb, line 143
def constraint_error(klass, column_name)
  "Malformed constraint `#{klass}##{column_name}'. If it's a legitimate column, and you are using a nested scaffold, please specify or double-check the reverse association name."
end
join_from_association_constraint(column) click to toggle source
# File lib/active_scaffold/constraints.rb, line 96
def join_from_association_constraint(column)
  if column.association.habtm?
    active_scaffold_habtm_joins.concat column.includes
  elsif !column.association.polymorphic?
    if column.association.belongs_to?
      active_scaffold_preload.concat column.includes
    else
      active_scaffold_references.concat column.includes
    end
  end
end
polymorphic_constraint_error(association) click to toggle source
# File lib/active_scaffold/constraints.rb, line 139
def polymorphic_constraint_error(association)
  "Malformed constraint. You have added a constraint for #{association.name} polymorphic association but value is not an array of class name and id."
end
register_constraint?(column_name, value) click to toggle source
# File lib/active_scaffold/constraints.rb, line 14
def register_constraint?(column_name, value)
  if params_hash?(value)
    false
  elsif value.is_a?(Array)
    column = active_scaffold_config.columns[column_name]
    column && value.size > (column.association&.polymorphic? ? 2 : 1)
  else
    true
  end
end
register_constraints_with_action_columns(constrained_fields = nil) click to toggle source

For each enabled action, adds the constrained columns to the ActionColumns object (if it exists). This lets the ActionColumns object skip constrained columns.

If the constraint value is a Hash, then we assume the constraint is a multi-level association constraint (the reverse of a has_many :through) and we do NOT register the constraint column. If the constraint value is an Array, or Array with more than 2 items for polymorphic column, we do NOT register the constraint column, as records will have different values in the column.

# File lib/active_scaffold/constraints.rb, line 32
def register_constraints_with_action_columns(constrained_fields = nil)
  constrained_fields ||= []
  constrained_fields |= active_scaffold_constraints.select { |k, v| register_constraint?(k, v) }.keys.collect(&:to_sym)
  exclude_actions = []
  %i[list update].each do |action_name|
    if active_scaffold_config.actions.include? action_name
      exclude_actions << action_name unless active_scaffold_config.send(action_name).hide_nested_column
    end
  end

  # we actually want to do this whether constrained_fields exist or not, so that we can reset the array when they don't
  active_scaffold_config.actions.each do |action_name|
    next if exclude_actions.include?(action_name)
    action = active_scaffold_config.send(action_name)
    next unless action.respond_to? :columns
    action.columns.constraint_columns = constrained_fields
  end
end