`addMetricIdsListener`

The addMetricIdsListener method registers a listener function with the Metrics object that will be called whenever a Metric definition is added or removed.

addMetricIdsListener(listener: MetricIdsListener): string

	Type	Description
`listener`	`MetricIdsListener`	The function that will be called whenever a `Metric` definition is added or removed.
returns	`string`

The provided listener is a MetricIdsListener function, and will be called with a reference to the Metrics object.

Example

This example creates a Store, a Metrics object, and then registers a listener that responds to the addition and the removal of a Metric definition.

import {createMetrics, createStore} from 'tinybase';

const store = createStore().setTable('species', {
  dog: {price: 5},
  cat: {price: 4},
  worm: {price: 1},
});

const metrics = createMetrics(store);
const listenerId = metrics.addMetricIdsListener((metrics) => {
  console.log(metrics.getMetricIds());
});

metrics.setMetricDefinition('highestPrice', 'species', 'max', 'price');
// -> ['highestPrice']
metrics.delMetricDefinition('highestPrice');
// -> []

metrics.delListener(listenerId);

Since

v4.1.0