Diffusion JavaScript API 6.2.8

Class: Updater

Updater

new Updater()

An updater provides methods to update a topic on the server with a new supplied value, like Session.topics#update, but within the context of an exclusive TopicUpdateHandler registration. If the update is successful it will call the result's success callback, and any sessions subscribed to the same topic will be notified of a topic update.

An updater may only update topics at or below the registration path of the TopicUpdateHandler from which it was produced.

The result will fail if the update was not successful. It is necessary for the topic to exist, and that the value type must be valid for the topic, for example a topic added with Metadata.Integer cannot accept a string value. Updates will also fail if the TopicUpdateHandler this updater was created from is in a standby or closed state.

Deprecated:
Example
updater.update('foo/bar', 123).then(function() {
    // Update successful
}, function(err) {
    // Update failed
});

Methods

update(topicPath, value)

Update a topic

Prefer #updateValue when updating a Double or Int64 topic. This method can infer the wrong data type when updating a Double topic with a value that does not have a fractional component.

Parameters:
Name Type Description
topicPath String

The topic to update
value Object

The value to update the topic with
Returns:
  • The Result.<undefined> of the update call
Type
Result.<undefined>

updateValue(topicPath, value, datatype)

Update a topic with a specified data type.

Parameters:
Name Type Description
topicPath String

The topic to update
value Object

The value to update the topic with
datatype Datatype

The data type to be used for encoding the value
Returns:
  • The Result.<undefined> of the update call
Type
Result.<undefined>