queryBus.on¶
The on method allows to listen to the query similarly to how addEventListener works for DOM events.
Input parameters¶
messageName¶
messageName is a mandatory parameter of the string type which represents the name of the message to listen to.
listener¶
listener is a mandatory parameter of type TMessageListener which represents a callback for the query emission.
Example¶
To listen to any query emitted by the Query Bus you can use the on method:
useStorefront(async (storefront) => {
storefront.queryBus.on('example-query', () => {
console.log('Listening to the query...')
});
});
Example¶
Remember that the query bus does not allow two listeners:
useStorefront(async (storefront) => {
storefront.query.on('example-query', () => {
console.log('Listening to the query...')
});
storefront.queryBus.on('example-query', () => { // Error: Maximum number of listeners reached
console.log('Listening to the query for the second time...')
});
});
Listening with on and once at the same time is also not allowed:
useStorefront(async (storefront) => {
storefront.query.once('example-query', () => {
console.log('Listening to the query...')
});
storefront.query.on('example-query', () => { // Error: Maximum number of listeners reached
console.log('Listening to the query with on...')
});
});