Javascript – How to access Vuex state property from a Vuex action

javascriptvue.jsvuejs2vuex

Currently I have a store with 2 state properties – version and champions + 2 actions that make GET requests and then commit to the state. The second GET requests URL needs to include the version which I've gotten from the first GET request as shown here:

axios.get("https://ddragon.leagueoflegends.com/cdn/" + X + "/data/en_US/champion.json")

The X in this code is supposed to be the Vuex state version property. If I wanted to access that property from outside the Vuex store, I would do it like this:

this.$store.state.version

This doesn't seem to work when I try it in the store though. How am I supposed to access the version state property from inside the getChampions action?

Code:

export default new Vuex.Store({
    state: {
        version: null,
        champions: null
    },
    mutations: {
        version(state, data){
            state.version = data.version
        },
        champions(state, data){
            state.champions = data.champions
        }
    },
    actions: {
        getVersion({commit}){
            axios.get("http://ddragon.leagueoflegends.com/api/versions.json")
            .then((response) => {
                commit('version', {
                    version: response.data[0]
                })
            })
            .catch(function (error) {
                console.log(error);
            })
        },
        getChampions({commit}){
            axios.get("https://ddragon.leagueoflegends.com/cdn/" + X + "/data/en_US/champion.json")
            .then((response) => {
                commit('champions', {
                    champions: response.data.data
                })
            })
            .catch(function (error) {
                console.log(error);
            })
        }
    }
})

Best Answer

you should add another atribute to your function that requires to access state:

getChampions({commit, state}){
            axios.get("https://ddragon.leagueoflegends.com/cdn/" + state.version + "/data/en_US/champion.json")
            .then((response) => {
                commit('champions', {
                    champions: response.data.data
                })
            })
            .catch(function (error) {
                console.log(error);
            })
        }

Related Solutions

Javascript – How to check if an object has a specific property in JavaScript

I'm really confused by the answers that have been given - most of them are just outright incorrect. Of course you can have object properties that have undefined, null, or false values. So simply reducing the property check to typeof this[property] or, even worse, x.key will give you completely misleading results.

It depends on what you're looking for. If you want to know if an object physically contains a property (and it is not coming from somewhere up on the prototype chain) then object.hasOwnProperty is the way to go. All modern browsers support it. (It was missing in older versions of Safari - 2.0.1 and older - but those versions of the browser are rarely used any more.)

If what you're looking for is if an object has a property on it that is iterable (when you iterate over the properties of the object, it will appear) then doing: prop in object will give you your desired effect.

Since using hasOwnProperty is probably what you want, and considering that you may want a fallback method, I present to you the following solution:

var obj = {
    a: undefined,
    b: null,
    c: false
};

// a, b, c all found
for ( var prop in obj ) {
    document.writeln( "Object1: " + prop );
}

function Class(){
    this.a = undefined;
    this.b = null;
    this.c = false;
}

Class.prototype = {
    a: undefined,
    b: true,
    c: true,
    d: true,
    e: true
};

var obj2 = new Class();

// a, b, c, d, e found
for ( var prop in obj2 ) {
    document.writeln( "Object2: " + prop );
}

function hasOwnProperty(obj, prop) {
    var proto = obj.__proto__ || obj.constructor.prototype;
    return (prop in obj) &&
        (!(prop in proto) || proto[prop] !== obj[prop]);
}

if ( Object.prototype.hasOwnProperty ) {
    var hasOwnProperty = function(obj, prop) {
        return obj.hasOwnProperty(prop);
    }
}

// a, b, c found in modern browsers
// b, c found in Safari 2.0.1 and older
for ( var prop in obj2 ) {
    if ( hasOwnProperty(obj2, prop) ) {
        document.writeln( "Object2 w/ hasOwn: " + prop );
    }
}

The above is a working, cross-browser, solution to hasOwnProperty, with one caveat: It is unable to distinguish between cases where an identical property is on the prototype and on the instance - it just assumes that it's coming from the prototype. You could shift it to be more lenient or strict, based upon your situation, but at the very least this should be more helpful.

Javascript – Remove properties from objects (JavaScript)

To remove a property from an object (mutating the object), you can do it like this:

delete myObject.regex;
// or,
delete myObject['regex'];
// or,
var prop = "regex";
delete myObject[prop];

Demo

var myObject = {
    "ircEvent": "PRIVMSG",
    "method": "newURI",
    "regex": "^http://.*"
};
delete myObject.regex;

console.log(myObject);

For anyone interested in reading more about it, Stack Overflow user kangax has written an incredibly in-depth blog post about the delete statement on their blog, Understanding delete. It is highly recommended.

If you'd like a new object with all the keys of the original except some, you could use the destructuring.

Demo

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};

const {regex, ...newObj} = myObject;

console.log(newObj);   // has no 'regex' key
console.log(myObject); // remains unchanged

Best Answer

Related Solutions

Javascript – How to check if an object has a specific property in JavaScript

Javascript – Remove properties from objects (JavaScript)

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