Class: SQLite::Database::FunctionProxy

Class SQLite::Database::FunctionProxy |
In: | lib/sqlite/database.rb
Parent: | Object

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.

Methods

- []
- []=
- count
- new
- set_error
- set_result

Public Class methods
new( func, context=nil )

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.

[ show source ]

         # File lib/sqlite/database.rb, line 628
    628:       def initialize( func, context=nil )
    629:         @func = func
    630:         @context = context
    631:       end

Public Instance methods
[]( key )

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

[ show source ]

         # File lib/sqlite/database.rb, line 655
    655:       def []( key )
    656:         ensure_aggregate!
    657:         @context[ key ]
    658:       end

[]=( key, value )

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

[ show source ]

         # File lib/sqlite/database.rb, line 662
    662:       def []=( key, value )
    663:         ensure_aggregate!
    664:         @context[ key ] = value
    665:       end

count()

(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.

[ show source ]

         # File lib/sqlite/database.rb, line 648
    648:       def count
    649:         ensure_aggregate!
    650:         SQLite::API.aggregate_count( @func )
    651:       end

set_error( error )

Set the result of the function to the given error message, which must be a string. The function will then return that error.

[ show source ]

         # File lib/sqlite/database.rb, line 641
    641:       def set_error( error )
    642:         SQLite::API.set_result_error( @func, error )
    643:       end

set_result( result )

Set the result of the function to the given value. The function will then return this value.

[ show source ]

         # File lib/sqlite/database.rb, line 635
    635:       def set_result( result )
    636:         SQLite::API.set_result( @func, result )
    637:       end

[Validate]