Case¶

classmethod Observable.case(selector, sources, default_source=None, scheduler=None)¶

Uses selector to determine which source in sources to use. There is an alias ‘switch_case’.

Example: 1 - res = rx.Observable.case(selector, { ‘1’: obs1, ‘2’: obs2 }) 2 - res = rx.Observable.case(selector, { ‘1’: obs1, ‘2’: obs2 }, obs0) 3 - res = rx.Observable.case(selector, { ‘1’: obs1, ‘2’: obs2 },

scheduler=scheduler)

Keyword arguments: :param types.FunctionType selector: The function which extracts the value

for to test in a case statement.

Parameters:	sources (list) – A object which has keys which correspond to the case statement labels. default_source (Observable) – The observable sequence or Promise that will be run if the sources are not matched. If this is not provided, it defaults to rx.Observabe.empty with the specified scheduler.
Returns:	An observable sequence which is determined by a case statement.
Return type:	Observable

classmethod Observable.defer(observable_factory)¶

Returns an observable sequence that invokes the specified factory function whenever a new observer subscribes.

Example: 1 - res = rx.Observable.defer(lambda: rx.Observable.from_([1,2,3]))

Keyword arguments: :param types.FunctionType observable_factory: Observable factory function

to invoke for each observer that subscribes to the resulting sequence.

Returns:	An observable sequence whose observers trigger an invocation

of the given observable factory function. :rtype: Observable

classmethod Observable.if_then(condition, then_source, else_source=None, scheduler=None)¶

Determines whether an observable collection contains values.

Example: 1 - res = rx.Observable.if(condition, obs1) 2 - res = rx.Observable.if(condition, obs1, obs2) 3 - res = rx.Observable.if(condition, obs1, scheduler=scheduler)

Keyword parameters: condition – {Function} The condition which determines if the

then_source or else_source will be run.

then_source – {Observable} The observable sequence or Promise that

will be run if the condition function returns true.

else_source – {Observable} [Optional] The observable sequence or

Promise that will be run if the condition function returns False. If this is not provided, it defaults to rx.Observable.empty

scheduler – [Optional] Scheduler to use.

Returns an observable {Observable} sequence which is either the then_source or else_source.

classmethod Observable.switch_case(selector, sources, default_source=None, scheduler=None)¶

Uses selector to determine which source in sources to use. There is an alias ‘switch_case’.

Example: 1 - res = rx.Observable.case(selector, { ‘1’: obs1, ‘2’: obs2 }) 2 - res = rx.Observable.case(selector, { ‘1’: obs1, ‘2’: obs2 }, obs0) 3 - res = rx.Observable.case(selector, { ‘1’: obs1, ‘2’: obs2 },

scheduler=scheduler)

Keyword arguments: :param types.FunctionType selector: The function which extracts the value

for to test in a case statement.

Parameters:	sources (list) – A object which has keys which correspond to the case statement labels. default_source (Observable) – The observable sequence or Promise that will be run if the sources are not matched. If this is not provided, it defaults to rx.Observabe.empty with the specified scheduler.
Returns:	An observable sequence which is determined by a case statement.
Return type:	Observable