Returning Promises from Vuex actions
It is considered as a good practice to return a promise object from an action. In Vuex actions are asynchronous. If an action is complete , there is no way to detect that. You can return a Promise to let the calling function know that the action is complete. In the below example myAction returns a Promise. Then asynchronously makes a http call and resolves or rejects the Promise later.
actions: { myAction(context, data) { return new Promise((resolve, reject) => { // Do something here... lets say, a http call using vue-resource this.$http("/api/something").then(response => { // http success, call the mutator and change something in state resolve(response); // Let the calling function know that http is done. You may send some data back }, error => { // http failed, let the calling function know that action did not work out reject(error); }) }) }
When the Vue component initiates myAction it will get the Promise object back and it can know whether the action was successful or not.
export default { mounted: function() { // This component just got created. Lets fetch some data here using an action this.$store.dispatch("myAction").then(response => { console.log("Got some data, now lets show something in this component") }, error =>{ console.error("Got nothing from server. Prompt user to check internet connection and try again") }) } }The mutators are synchronous and they can change things in the state. They are normally called from actions.
Comments
0 comments
Please Sign in or Create an account to Post Comments