Class: SQLite3::Database::FunctionProxy

Inherits:
Object
  • Object
show all
Defined in:
lib/sqlite3/database.rb

Overview

A helper class for dealing with custom functions (see #create_function, #create_aggregate, and #create_aggregate_handler). It encapsulates the opaque function object that represents the current invocation. It also provides more convenient access to the API functions that operate on the function object.

This class will almost always be instantiated indirectly, by working with the create methods mentioned above.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ FunctionProxy

Create a new FunctionProxy that encapsulates the given func object. If context is non-nil, the functions context will be set to that. If it is non-nil, it must quack like a Hash. If it is nil, then none of the context functions will be available.



709
710
711
712
 
# File 'lib/sqlite3/database.rb', line 709

def initialize
  @result   = nil
  @context  = {}
end

Instance Attribute Details

#result ⇒ Object

Returns the value of attribute result.



703
704
705
 
# File 'lib/sqlite3/database.rb', line 703

def result
  @result
end

Instance Method Details

#[](key) ⇒ Object

Returns the value with the given key from the context. This is only available to aggregate functions.



729
730
731
 
# File 'lib/sqlite3/database.rb', line 729

def []( key )
  @context[ key ]
end

#[]=(key, value) ⇒ Object

Sets the value with the given key in the context. This is only available to aggregate functions.



735
736
737
 
# File 'lib/sqlite3/database.rb', line 735

def []=( key, value )
  @context[ key ] = value
end

#count ⇒ Object

(Only available to aggregate functions.) Returns the number of rows that the aggregate has processed so far. This will include the current row, and so will always return at least 1.



723
724
725
 
# File 'lib/sqlite3/database.rb', line 723

def count
  @driver.aggregate_count( @func )
end

#set_error(error) ⇒ Object

Set the result of the function to the given error message. The function will then return that error.



716
717
718
 
# File 'lib/sqlite3/database.rb', line 716

def set_error( error )
  @driver.result_error( @func, error.to_s, -1 )
end