Class: SQLite3::Database::FunctionProxy

Class SQLite3::Database::FunctionProxy |
In: | lib/sqlite3/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
- result=
- set_error
- set_result

Public Class methods
new( driver, 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/sqlite3/database.rb, line 671
    671:       def initialize( driver, func, context=nil )
    672:         @driver = driver
    673:         @func = func
    674:         @context = context
    675:       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/sqlite3/database.rb, line 704
    704:       def []( key )
    705:         ensure_aggregate!
    706:         @context[ key ]
    707:       end

[]=( key, value )

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

[ show source ]

         # File lib/sqlite3/database.rb, line 711
    711:       def []=( key, value )
    712:         ensure_aggregate!
    713:         @context[ key ] = value
    714:       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/sqlite3/database.rb, line 697
    697:       def count
    698:         ensure_aggregate!
    699:         @driver.aggregate_count( @func )
    700:       end

result=( result )

Calls set_result to set the result of this function.

[ show source ]

         # File lib/sqlite3/database.rb, line 678
    678:       def result=( result )
    679:         set_result( result )
    680:       end

set_error( error )

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

[ show source ]

         # File lib/sqlite3/database.rb, line 690
    690:       def set_error( error )
    691:         @driver.result_error( @func, error.to_s, -1 )
    692:       end

set_result( result, utf16=false )

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

[ show source ]

         # File lib/sqlite3/database.rb, line 684
    684:       def set_result( result, utf16=false )
    685:         @driver.result_text( @func, result, utf16 )
    686:       end

[Validate]