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.
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.
# File lib/sqlite3/database.rb, line 540 def initialize @result = nil @context = {} end
Returns the value with the given key from the context. This is only available to aggregate functions.
# File lib/sqlite3/database.rb, line 560 def []( key ) @context[ key ] end
Sets the value with the given key in the context. This is only available to aggregate functions.
# File lib/sqlite3/database.rb, line 566 def []=( key, value ) @context[ key ] = value end
(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.
# File lib/sqlite3/database.rb, line 554 def count @driver.aggregate_count( @func ) end
Set the result of the function to the given error message. The function will then return that error.
# File lib/sqlite3/database.rb, line 547 def set_error( error ) @driver.result_error( @func, error.to_s, -1 ) end