Signal

A stream of all values in this signal, excluding the initial value.

When re-starting this stream, it emits the signal's new current value if and only if something has caused the signal's value to be updated or re-evaluated while the changes stream was stopped. This way the changes stream stays in sync with the signal even after restarting.

Trigger JS debugger when signal is evaluating its initial value (if when passes at that time)

Log when signal is evaluating its initial value (if when passes at that time)

Execute fn when signal is evaluating its currentValueFromParent. This is typically triggered when evaluating signal's initial value onStart, as well as on subsequent re-starts when the signal is syncing its value to the parent's new current value.

See also debug methods in com.raquo.airstream.debug.DebuggableObservable

Distinct all values (both events and errors) using a comparison function

Add a noop observer to this signal to ensure that it's started. This lets you access .now and .tryNow on the resulting StrictSignal.

You can use myStream.toWeakSignal.observe.tryNow() to read the last emitted value from event streams just as well.

Convert this to an observable that emits Failure(err) instead of erroring

A signal that emits the accumulated value every time that the parent signal emits.

A signal that emits the accumulated value every time that the parent signal emits.

Like split, but uses index of the item in the list as the key.

This .split-s a Signal of an Option by the Option's isDefined property. If you want a different key, use the .split operator directly.

Subscribe an external observer to this observable

Trigger JS debugger for emitted events and errors if when passes Note: for Signals this also triggers onStart (with the current value at the time)

Trigger JS debugger for emitted errors (but not events) if when passes Note: for Signals this also triggers onStart (if current value is an error)

Trigger JS debugger for emitted events (but not errors) if when passes Note: for Signals this also triggers onStart (if current value is not an error)

Trigger JS debugger when the observable starts and stops

Trigger JS debugger when the observable starts

Trigger JS debugger when the observable stops

Log emitted events and errors if when condition passes, using dom.console.log if useJsLogger is true. Note: for Signals this also triggers on start (with the current value at the time)

Log emitted errors (but not regular events) if when condition passes Note: for Signals this also triggers onStart (if current value is an error)

Log emitted events (but not errors) if when condition passes, using dom.console.log if useJsLogger is true. Note: for Signals this also triggers onStart (if current value is not an error)

Log when the observable starts and stops

Log when the observable starts

Log when the observable stops

Execute fn on every emitted event or error Note: for Signals this also triggers onStart (with the current value at the time)

Execute fn on every emitted error (but not regular events) Note: for Signals this also triggers onStart (if current value is an error)

Execute fn on every emitted event (but not error) Note: for Signals this also triggers onStart (if current value is not an error)

Execute callbacks on when the observable starts and stops

Execute callbacks on when the observable starts

Execute callbacks on when the observable stops

Return the observable's topoRank. This does not affect the observable in any way.

Create a new observable that listens to the original, and set the displayName of the new observable. This is different from setDisplayName.

If you say stream.debugWithName("foo").debugLog(), the displayName used by the logger will be "foo" verbatim, whereas if you say stream.setDisplayName("foo").debugLog(), the logger's displayName will be "foo|Debug" – with a suffix – to differentiate it from the "foo" displayName of stream itself.

This is the method that subclasses override to preserve the user's ability to set custom display names.

Distinct events (but keep all errors) by == (equals) comparison

Distinct events (but keep all errors) using a comparison function

Distinct events (but keep all errors) by matching key Note: key(event) might be evaluated more than once for each event

Distinct events (but keep all errors) by reference equality (eq)

Distinct errors only (but keep all events) using a comparison function

Airstream may internally use Scala library functions which use == or hashCode for equality, for example List.contains. Comparing observables by structural equality pretty much never makes sense, yet it's not that hard to run into that, all you need is to create a case class subclass, and the Scala compiler will generate a structural-equality equals and hashCode methods for you behind the scenes.

To prevent that, we make equals and hashCode methods final, using the default implementation (which is reference equality).

Create an external observer from a function and subscribe it to this observable.

Note: since you won't have a reference to the observer, you will need to call Subscription.kill() to unsubscribe

Force reference equality checks. See comment for equals.

value is passed by name, so it will be evaluated whenever the Observable fires. Use it to sample mutable values (e.g. myInput.ref.value in Laminar).

See also: mapToStrict

value is evaluated strictly, only once, when this method is called.

See also: mapTo

Set the display name for this instance (observable or observer).

• This method modifies the instance and returns this. It does not create a new instance.
• New name you set will override the previous name, if any. This might change in the future. For the sake of sanity, don't call this more than once for the same instance.
• If display name is set, toString will output it instead of the standard type@hashcode string

Unwrap Try to "undo" recoverToTry – Encode Failure(err) as observable errors, and Success(v) as events

Override defaultDisplayName instead of this, if you need to.

Convert this observable to a signal of Option[A]. If it is a stream, set initial value to None.