Class: Zena::Use::QueryNode::Compiler

Inherits:
QueryBuilder::Processor
  • Object
show all
Defined in:
lib/zena/use/query_node.rb

Constant Summary collapse

CORE_CONTEXTS = 
%w{parent project section}

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Class Attribute Details

.filter_fields ⇒ Object

Returns the value of attribute filter_fields.



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# File 'lib/zena/use/query_node.rb', line 128

def filter_fields
  @filter_fields
end

Instance Attribute Details

#context ⇒ Object (readonly)

?



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# File 'lib/zena/use/query_node.rb', line 109

def context
  @context
end

Class Method Details

.add_filter_field(key, fld_def) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 130

def add_filter_field(key, fld_def)
  self.filter_fields[key] = fld_def
end

Instance Method Details

#get_scope_index_field(field_name) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 178

def get_scope_index_field(field_name)
  return nil if @query.main_class.real_class.column_names.include?(field_name)
  # 1. Try scope index
  klass = @query.main_class
  if index_model = klass.kind_of?(VirtualClass) ? klass.idx_class : nil
    index_model = Zena.resolve_const(index_model) rescue NilClass
    if index_model < Zena::Use::ScopeIndex::IndexMethods && index_model.column_names.include?(field_name)
      table_to_use = add_key_value_table('scope_index', index_model.table_name) do |tbl_name|
        # This block is only executed once (ON clause)
        "#{table('nodes')}.id = #{tbl_name}.node_id"
      end
      "#{table_to_use}.#{field_name}"
    else
      # invalid field_name: ignore
      nil
    end
  else
    nil
  end
end

#need_join_scope?(scope_name) ⇒ Boolean

Special case ‘in site’ that is a noop scope and just avoids the insertion of the default ‘in parent’ scope.

Returns:

  • (Boolean) 


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# File 'lib/zena/use/query_node.rb', line 467

def need_join_scope?(scope_name)
  scope_name != 'site'
end

#parse_custom_query_argument(key, value) ⇒ Object

******** And maybe overwrite these **********



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# File 'lib/zena/use/query_node.rb', line 424

def parse_custom_query_argument(key, value)
  return nil unless value
  super.gsub(/(RELATION_ID|KPATH_VALUE|NODE_ATTR|SECURE_TABLE)\(([^)]+)\)|(REF_DATE|NODE_ID|VISITOR_LANG)/) do
    type, value = $1, $2
    type ||= $3
    case type
    when 'RELATION_ID'
      role = value
      if rel = RelationProxy.find_by_role(role.singularize)
        rel[:id]
      else
        raise ::QueryBuilder::Error.new("Custom query: could not find Relation '#{role}'")
      end
    when 'KPATH_VALUE'
      klass_name = value
      if rel = VirtualClass[klass_name]
        rel.kpath
      else
        raise ::QueryBuilder::Error.new("Custom query kpath: could not find VirtualClass '#{role}'")
      end
    when 'SECURE_TABLE'
      table_name = value
      add_filter "\#{secure_scope('#{table_name}')}"
    when 'NODE_ATTR'
      attribute = value
      if Node.safe_method_type([attribute])
        insert_bind("#{node_name}.#{attribute}")
      else
        # not found: consider it's a property
        insert_bind("#{node_name}.prop[#{attribute.inspect}]")
      end
    when 'REF_DATE'
      context[:ref_date] ? insert_bind(context[:ref_date]) : 'now()'
    when 'NODE_ID'
      insert_bind("#{node_name}.id")
    when 'VISITOR_LANG'
      insert_bind("visitor.lang")
    end
  end
end

#process_attr(attribute) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 164

def process_attr(attribute)
  case attribute
  when 'project_id', 'section_id', 'discussion_id'
    # Special accessor
    insert_bind "#{node_name}.get_#{attribute}"
  when 'id', 'parent_id'
    # Not RubyLess safe
    insert_bind "#{node_name}.#{attribute}"
  else
    # Use RubyLess
    super
  end
end

#process_equal(left, right, is_not = nil) ⇒ Object

Handle special case for ‘class = ’ and ‘role = ’ and ‘foo.date =’



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# File 'lib/zena/use/query_node.rb', line 298

def process_equal(left, right, is_not = nil)
  if (left == [:field, 'class'] || left == [:field, 'klass']) && (right[0] == :field || right[0] == :string)
    if klass = Node.get_class(right.last)
      "#{field_or_attr('kpath')} #{is_not ? '<>' : '='} #{quote(klass.kpath)}"
    else
      raise ::QueryBuilder::Error.new("Unknown class #{right.last.inspect}.")
    end
  elsif left == [:field, 'role'] && (right[0] == :field || right[0] == :string)
    if role = Node.get_role(right[1])
      # FIXME: how to only add table once if the other clause in not an OR ?
      add_table('nodes_roles')
      "(#{table('nodes_roles')}.node_id = #{table('nodes')}.id AND #{table('nodes_roles')}.role_id = #{role.id})"
    end
  elsif left.first == :function && left.last.last == 'date'
    # transform "foo.date = baz"
    # [:function, [:field, "foo"], [:method, "date"]]
    # [:field, baz]
    # ==> into
    # "baz >= foo and foo < baz + 1 day"
    a = left[1]
    b = right
    process([:and, [:<=, b, a], [:<, a, [:+, b, [:interval, [:integer, '1'], 'day']]]])
  else
    process_op(:'=', left, right)
  end
end

#process_field(field_name) ⇒ Object

Overwrite this and take care to check for valid fields.



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# File 'lib/zena/use/query_node.rb', line 204

def process_field(field_name)
  if fld = @query.attributes_alias[field_name]
    # use custom query alias value defined in select clause: 'custom_a AS validation'
    if processing_filter?
      # We need to use the full original clause, except when the clause contains group functions (MAX, MIN, etc).
      # If the clause is too complex, we need to use something simpler or it will break (custom queries).
      "(#{fld})"
    else
      fld
    end
  elsif processing_filter? && map_def = self.class.filter_fields[field_name]
    # Special filter fields such as 'role', 'tag' or 'class'
    if map_def.kind_of?(String)
      return map_def
    elsif table_def = map_def[:table]
      use_name, source, target, filter = table_def
      table_to_use = add_key_value_table(use_name, target, map_def[:key]) do |tbl_name|
        # This block is only executed once
        filter.gsub(
          'TABLE1', table(source)
        ).gsub(
          'TABLE2', tbl_name
        )
      end
    else
      table_to_use = table
    end
    "#{table_to_use}.#{map_def[:key]}"
  elsif %w{id parent_id project_id section_id user_id}.include?(field_name) ||
    (Node.safe_method_type([field_name]) && Node.column_names.include?(field_name))
    "#{table}.#{field_name}"
  elsif @query.tables.include?('links') &&
       (key = field_name[/^l_(.+)$/,1]) &&
       (key == 'id' ||
        Zena::Use::Relations::LINK_ATTRIBUTES.include?(key.to_sym))
    "#{table('links')}.#{key}"
  elsif field_name == 'random'
    Zena::Db.sql_function(field_name, nil)
  else
    # property or real column

    # FIXME !!!! Why does this happen ?
    return nil if @query.main_class.columns.kind_of?(Array)


    column = @query.main_class.columns[field_name]
    if column && column.indexed?
      if column.index == true
        group_name = column.type
      elsif column.index =~ Property::Index::FIELD_INDEX_REGEXP
        # field in nodes
        return "#{table}.#{$1}"
      else
        group_name = column.index
      end

      index_table = @query.main_class.real_class.index_table_name(group_name)

      # We use the add_key_value_table rule to avoid inserting the
      # same index access twice.

      tbl = add_key_value_table(group_name, index_table, field_name) do |tbl_name|
        # This block is only executed once
        on_clause = "#{tbl_name}.node_id = #{table}.id AND #{tbl_name}.key = #{quote(field_name)}"
        if group_name.to_s =~ /^ml_/
          on_clause << " AND #{tbl_name}.lang = #{quote(visitor.lang)}"
        end
        # no need for distinct, the new table makes a 1-1 relation
        # ON CLAUSE
        on_clause
        
      end

      "#{tbl}.value"
    else
      super # raises an error
    end
  end
end

#process_function(arg, method, *args) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 411

def process_function(arg, method, *args)
  # Resolve scope index fields
  arg, method = resolve_scope_idx_fields(arg, method)
  if method
    arg, method = process(arg), process(method)
    args = [arg] + args.map{|a| process(a)}
    Zena::Db.sql_function(method, *args)
  else
    process(arg)
  end
end

#process_idx_field(scope_field) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 199

def process_idx_field(scope_field)
  scope_field
end

#process_like(left, right, is_not = nil) ⇒ Object

Handle special case for ‘class like ’



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# File 'lib/zena/use/query_node.rb', line 326

def process_like(left, right, is_not = nil)
  if (left == [:field, 'class'] || left == [:field, 'klass']) && right[0] == :field
    if klass = Node.get_class(right[1])
      "#{field_or_attr('kpath')} #{is_not ? 'NOT ' : ''}LIKE #{quote(klass.kpath + '%')}"
    else
      raise ::QueryBuilder::QueryException.new("Unknown class #{right.last.inspect}.")
    end
  else
    process_op(:like, left, right)
  end
end

#process_not(arg) ⇒ Object

:like, [:field, “class”], [:field, “Image”]


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# File 'lib/zena/use/query_node.rb', line 339

def process_not(arg)
  if (arg[1] == [:field, 'class'] || arg[1] == [:field, 'klass']) && arg[0] == :like
    process_like(arg[1], arg[2], true)
  else
    super
  end
end

#process_not_equal(left, right) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 289

def process_not_equal(left, right)
  if (left == [:field, 'class'] || left == [:field, 'klass']) && (right[0] == :field || right[0] == :string)
    process_equal(left, right, true)
  else
    process_op(:'<>', left, right)
  end
end

#process_param(pagination_key) ⇒ Object

Process pagination parameter



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# File 'lib/zena/use/query_node.rb', line 285

def process_param(pagination_key)
  "params[#{pagination_key.to_sym.inspect}]"
end

#resolve_main_class(class_name) ⇒ Object

Resolve ‘main_class’ from a class name.



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# File 'lib/zena/use/query_node.rb', line 123

def resolve_main_class(class_name)
  VirtualClass[class_name]
end

#resolve_missing_table(query, table_name, table_alias) ⇒ Object

This is used to avoid finding random indexed objects or links in clauses with and without link filters like this: “image or icon” (‘image’ is a filter in ‘parent’ scope, ‘icon’ is a relation found through links).



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# File 'lib/zena/use/query_node.rb', line 474

def resolve_missing_table(query, table_name, table_alias)
  if table_name =~ /^idx_nodes/
    # index tables
    query.where.insert 0, "#{table_alias}.node_id = 0"
  elsif table_name == 'links' || table_name =~ /^idx_/
    # index tables
    query.where.insert 0, "#{table_alias}.id = 0"
  else
    # Raise an error
    super
  end
end

#resolve_scope_idx_fields(arg1, arg2) ⇒ Object 



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# File 'lib/zena/use/query_node.rb', line 347

def resolve_scope_idx_fields(arg1, arg2)
  if arg1.first == :function
    # contact.log_at.year
    # arg1 = [:function, [:field, "tag"], [:method, "created_at"]]
    # arg2 = [:method, "year"]
    class_name = arg1[1][1]
    field_name = arg1[2][1]
    function  = arg2
  elsif arg1[0] == :field && arg2[0] == :method
    # contact.log_at  or  log_at.year
    # arg1 = [:field, "contact"]
    class_name = arg1[1]
    # arg2 = [:method, "name"]
    field_name = arg2[1]
    function   = nil
  else
    return [arg1, arg2]
  end

  scope_idx_field = "#{class_name}_#{field_name}"
  if fld = get_scope_index_field(scope_idx_field)
    return [[:idx_field, fld], function]
  else
    # 2. Try to use relation as scope filter 'hot.title = "xxx"', 'hot.title = "xxx"'
    # Multiple links with hot.id = 334 and hot2.id = 323...
    rel = class_name.sub(/\d$/,'')

    source_kpath = @query.main_class.kpath

    if rel = RelationProxy.find_by_role(rel.singularize, source_kpath)
      table_to_use = add_key_value_table('jnode', 'nodes', class_name) do |tbl_name|
        # This block is only executed once per relation name (once for 'hot', once for 'hot2')
        # TODO: Can we remove this ?
        distinct!
        lnk = add_key_value_table('links', 'links', class_name) do |lt|
          "#{lt}.#{rel.link_side} = #{table(main_table)}.id AND #{lt}.relation_id = #{rel.id}"
        end
        
        %Q{#{tbl_name}.id = #{lnk}.#{rel.other_side}}
      end
      
      # Temporarily move to the remote class
      tbl_alias_bak = context[:table_alias]
      context[:table_alias] = table_to_use
      main_class_bak = @query.main_class
      
        @query.main_class = rel.other_vclass
        fld = process_field(field_name)
        
      # Move back
      @query.main_class = main_class_bak
      context[:table_alias] = tbl_alias_bak
      if fld
        [[:idx_field, fld], function]
      else
        nil
      end
    else
      # not a scope index field
      return [arg1, arg2]
    end
  end
end

#scope_fields(scope) ⇒ Object

Scope current context with previous context. For example:

                        current         previous
['parent_id', 'id'] ==> no1.parent_id = nodes.id



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# File 'lib/zena/use/query_node.rb', line 148

def scope_fields(scope)
  case scope
  when 'self'
    ['parent_id', 'id']
  when *CORE_CONTEXTS
    last? ? %W{#{scope}_id #{scope}_id} : %W{#{scope}_id id}
  when 'site', main_table
    # not an error, but do not scope
    []
  else
    #if CORE_CONTEXTS.include?(scope)
    # error
    nil
  end
end