Vue 2.0, where to place local functions - javascript

Where do you correctly place local functions in vue 2.x?
I could just place them in the "methods" object, but I'd like them to be completely local to the instance if thats possible.
Sort of like this in Plain JS :
window._global = (function () {
function _secretInsideFunct(){
return "FooBar";
}
var __localObject = {
outsideFunct : function () {
return _secretInsideFunct();
}
}
return __localObject;
}());
..where _global._secretInsideFunct() wouldnt be accessible anywhere else but from inside the _global object.
In this specific case I want to make a function that creates an array object if it doesn't exist.. Something like:
function CreateOrSet (workArray, itemName, itemValue ){
var salaryRow = self.Status.Rows.find(r => r.recordID == itemName);
if (!salaryRow) {
salaryRow = { recordID: itemName, recordAmount: 0, recordName: "Løn" };
self.Status.Rows.push(salaryRow);
}
salaryRow.recordAmount = itemValue ;
}
..but a general approach for these cases is better :)

Now this function doesn't looks like a utility or helper function, but relate to a state, Status.Rows. If I were you, I will define it as close as to the state or the module that the state being used.
If the state will be used across the app, maybe I will define it in entry file, index.js or app.vue.
Or If you are using vuex, you can define it as an vuex action. So you may do something like this:
const store = new Vuex.Store({
state: {
status: {
rows: []
},
mutations: {
pushRow (state, salaryRow) {
state.status.rows.push(salaryRow)
},
changeAmount (state, id, amount) {
const salaryRow = state.status.Rows.find(r => r.recordID === id)
salaryRow.recordAmount = amount
}
},
actions: {
createRow (context, itemName) {
const salaryRow = { recordID: itemName, recordAmount: 0, recordName: "Løn" };
context.commit('pushRow', salaryRow)
}
}
})
You can put all of the code to a single action, it is just an idea, how you organize your code depend on your needs.

Related

Sending some but not all args to a function without defining nulls

I'm using vue 3 and composable files for sharing some functions through my whole app.
My usePluck.js composable file looks like
import { api } from 'boot/axios'
export default function usePlucks() {
const pluckUsers = ({val = null, excludeIds = null}) => api.get('/users/pluck', { params: { search: val, exclude_ids: excludeIds }})
return {
pluckUsers
}
}
In order to make use of this function in my component I do
<script>
import usePlucks from 'composables/usePlucks.js'
export default {
name: 'Test',
setup() {
const { pluckUsers } = usePlucks()
onBeforeMount(() => {
pluckUsers({excludeIds: [props.id]})
})
return {
}
}
}
</script>
So far so good, but now I'd like to even be able to not send any args to the function
onBeforeMount(() => {
pluckUsers()
})
But when I do that, I get
Uncaught TypeError: Cannot read properties of undefined (reading 'val')
I assume it's because I'm not sending an object as argument to the function, therefore I'm trying to read val from a null value: null.val
What I'm looking for is a way to send, none, only one, or all arguments to the function with no need to set null values:
// I don't want this
pluckUsers({})
// Nor this
pluckUsers({val: null, excludeIds: [props.id]})
I just want to send only needed args.
Any advice about any other approach will be appreciated.
import { api } from 'boot/axios'
export default function usePlucks() {
const pluckUsers = ({val = null, excludeIds = null} = {}) => api.get('/users/pluck', { params: { search: val, exclude_ids: excludeIds }})
return {
pluckUsers
}
}
I believe this is what you're looking for. The { ... } = {}
EDIT: It didn't work without this because with no argument the destructuring failed because it can't match an object. That's why you also need a default value on the parameter object, also called simulated named parameter.

Function as unlabeled prop in JavaScript. What is this called, and how does it work?

I saw this code today, which does something I've never seen before. It has an object which itself has an unlabeled property that is a function.
emails = {
type: EmailType,
args: { id: { type: GraphQLID } },
resolve(parentValue, args) {
const query = `SELECT * FROM "emails" WHERE id=${args.id}`;
return db.conn.one(query)
.then(data => {
return data;
})
.catch(err => {
return 'The error is', err;
});
}
}
}
I'd like to know more about this, but I have no idea what the proper keyterm for this is, and searching "function as property js" only yields really obvious stuff (ie {someProp: () => 42}).
I'm certain that both:
A. If I knew the right key term, it would be really easy to learn more and
B. The only way to make this keyterm easier to find is to have something someone would actually search lead to it. To that end, I'll include some extra SEO:
object has function but not at prop
function inlined in object
function in object
object has a function but it's not a prop
no propname for function
Anyways:
What is this called, and where can I find more information on it?
EDIT: Got links to docs. One thing to denote is the differences between
// these are the same, I think
const eg1 = { someFn() {} }
const eg2 = { someFn: function() {} }
// this is different in scope... I think
const someFn = () => {};
const eg3 = { someFn };
It is a Shorthand method name.
{ method() { /*...*/ } }
is equal to:
{ method: function() { /*...*/ } }

Where should I put function which would be used by two or more Vue.js components?

I have a function which takes an ID as an argument and finds the object to which this ID belongs from a JSON that is stored in the Vuex store. So far I have used the function in 1 component only, however, I recently created a second component which also requires that function. Currently I have just copied and pasted the function, however, this seems to be less than optimal. This is why I wonder where should this function be placed so that it's accessible from all components that need it.
I've been wondering if the Vuex store is a viable place to store the function but I'm not too sure so I decided to ask for your advice. Thanks
findChampionName(id){
let championId = id.toString();
let champion = Object.entries(this.$store.state.champions).find(([key,value]) => value.key === championId);
return champion[1]
}
Vuex store:
export default new Vuex.Store({
state: {
champions: null
},
mutations: {
champions(state, data){
state.champions = data.champions
}
},
actions: {
getChampions({commit, state}){
axios.get("https://ddragon.leagueoflegends.com/cdn/9.14.1/data/en_US/champion.json")
.then((response) => {
commit('champions', {
champions: response.data.data
})
})
.catch(function (error) {
console.log(error);
})
}
}
})
As far as I can see, you should use a vuex getter for your case:
getters: {
getChampionName => state => id => {
let championId = id.toString();
let champion = Object.entries(state.champions).find(([key,value]) => value.key === championId);
return champion[1]
}
}
And you can access that getter by passing the id: this.$store.getters['findChampionName'](id)

React to nested state change in Angular and NgRx

Please consider the example below
// Example state
let exampleState = {
counter: 0;
modules: {
authentication: Object,
geotools: Object
};
};
class MyAppComponent {
counter: Observable<number>;
constructor(private store: Store<AppState>){
this.counter = store.select('counter');
}
}
Here in the MyAppComponent we react on changes that occur to the counter property of the state. But what if we want to react on nested properties of the state, for example modules.geotools? Seems like there should be a possibility to call a store.select('modules.geotools'), as putting everything on the first level of the global state seems not to be good for overall state structure.
Update
The answer by #cartant is surely correct, but the NgRx version that is used in the Angular 5 requires a little bit different way of state querying. The idea is that we can not just provide the key to the store.select() call, we need to provide a function that returns the specific state branch. Let us call it the stateGetter and write it to accept any number of arguments (i.e. depth of querying).
// The stateGetter implementation
const getUnderlyingProperty = (currentStateLevel, properties: Array<any>) => {
if (properties.length === 0) {
throw 'Unable to get the underlying property';
} else if (properties.length === 1) {
const key = properties.shift();
return currentStateLevel[key];
} else {
const key = properties.shift();
return getUnderlyingProperty(currentStateLevel[key], properties);
}
}
export const stateGetter = (...args) => {
return (state: AppState) => {
let argsCopy = args.slice();
return getUnderlyingProperty(state['state'], argsCopy);
};
};
// Using the stateGetter
...
store.select(storeGetter('root', 'bigbranch', 'mediumbranch', 'smallbranch', 'leaf')).subscribe(data => {});
...
select takes nested keys as separate strings, so your select call should be:
store.select('modules', 'geotools')

Parenting this in Javascript

I'm trying to make the following code works without any luck, and I can't see a clear solution on how to do it.
export default {
model: null,
set: function (data) {
this.model = data
},
account: {
update: function (data) {
this.model.account = data
}
}
}
My issue here is that account.update fails because this.model does not exists. I suspect that the sub object gets a new this, hence my issue, but I don't know how to fix it.
I tried the alternative here :
export default (function () {
let model = null
function set (data) {
this.model = data // I also tried without the `this.` but without any luck too
},
function updateAccount(data) {
this.model.account = data
}
return {
'model': model,
'set': set,
'account': {
'update': updateAccount
}
}
})()
But apparently the same rule applies.
Maybe it's worth noting that I'm using Babel to compile ES6 down to ES5 javascript.
It fails because this refers (in this case) to the window object. Reference the object itself like this:
let myModel = {
model: null,
set: function (data) {
myModel.model = data // reference myModel instead of this
},
account: {
update: function (data) {
myModel.model.account = data // reference myModel instead of this
}
}
}
I would take an approach similar to your alternative solution. There is however no need to wrap your code in an IIFE, ES2015 modules are self-contained; you don't need an IIFE for encapsulation.
let model = null,
set = (data) => {
model = data;
},
updateAccount = (data) => {
if (!model) {
throw('model not set');
}
model.account = data;
};
export default {
model,
set,
account: {
update: updateAccount
}
};
Since you are already using Babel, I also used arrow functions and the new shorthand properties to make the code a little shorter/readable.

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