I have data I would like to use in multiple components and manipulate. For that reason I decided to start using store, but I don't know at what stage I'm supposed to do request to the server and set store data.
The question is probably asked before but I could not find it
Your question is not clearly but if you want to centralize your logic. Your store file looks like that:
state:{
user:{
id: "",
name: "",
...
..
.
}
}
getters:{
get_user: state => state.user,
get_userID: state => state.user.id,
...
}
mutations:{
SET_USER(state, payload){
state.user = payload
},
SET_USER_ID(state, payload){
state.user.id = payload
}
...
}
actions:{
add_user({ commit }, userData){
// you can make some http request here if you have
commit("SET_USER", userData)
}
}
Basically, above code is showing you a logic. If you want to get some data which is in state, you should had a getters. If you want to change some data which is in state, you should use mutations to make this. If you want to make some functionality like post user detail to server, fetching data from server something like this you should use actions and even you can make those changes in your actions, don't. Because actions work async, mutations not.
I hope this is answer what you looking for.
Related
I'm developing a helpdesk tool in which I have a kanban view.
I previously used nested serializers in my backend and I managed to have everything working with a single query but it's not scalable (and it was ugly) so I switched to another schema :
I query my helpdesk team ('test' in the screenshot)
I query the stages of that team ('new', 'in progress')
I query tickets for each stage in stages
So when I mount my component, I do the following :
async mounted () {
if (this.helpdeskTeamId) {
await this.getTeam(this.helpdeskTeamId)
if (this.team) {
await this.getTeamStages(this.helpdeskTeamId)
if (this.stages) {
for (let stage of this.stages) {
await this.getStageTickets(stage)
}
}
}
}
},
where getTeam, getTeamStages and getStageTickets are :
async getTeam (teamId) {
this.team = await HelpdeskTeamService.getTeam(teamId)
},
async getTeamStages (teamId) {
this.stages = await HelpdeskTeamService.getTeamStages(teamId)
for (let stage of this.stages) {
this.$set(stage, 'tickets', [])
}
},
async getStageTickets (stage) {
const tickets = await HelpdeskTeamService.getTeamStageTickets(this.helpdeskTeamId, stage.id)
// tried many things here below but nothing worked.
// stage.tickets = stage.tickets.splice(0, 0, tickets)
// Even if I try to only put one :
// this.$set(this.stages[this.stages.indexOf(stage)].tickets, 0, tickets[0])
// I see it in the data but It doesn't appear in the view...
// Even replacing the whole stage with its tickets :
// stage.tickets = tickets
// this.stages.splice(this.stages.indexOf(stage), 1, stage)
},
In getTeamStages I add an attribute 'tickets' to every stage to an empty list. The problem is when I query all the tickets for every stage. I know how to insert a single object in an array with splice or how to delete one object from an array but I don't know how to assign a whole array to an attribute of an object that is in an array while triggering the Vue reactivity. Here I'd like to put all the tickets (which is a list), to stage.tickets.
Is it possible to achieve this ?
If not, what is the correct design to achieve something similar ?
Thanks in advance !
EDIT:
It turns out that there was an error generated by the template part. I didn't think it was the root cause since a part of the view was rendered. I thought that it would have prevent the whole view from being rendered if it was the case. But finally, in my template I had a part doing stage.tickets.length which was working when using a single query to populate my view. When making my API more granular and querying tickets independently from stages, there is a moment when stage has no tickets attribute until I set it manually with this.$set(stage, 'tickets', []). Because of that, the template stops rendering and raises an issue. But the ways of updating my stage.tickets would have worked without that template issue.
I could update the stages reactively. Here is my full code; I used the push method of an array object and it works:
<template>
<div>
<li v-for="item in stages" :key="item.stageId">
{{ item }}
</li>
</div>
</template>
<script>
export default {
data() {
return {
stages: [],
};
},
methods: {
async getTeamStages() {
this.stages = [{ stageId: 1 }, { stageId: 2 }];
for (let stage of this.stages) {
this.$set(stage, "tickets", []);
}
for (let stage of this.stages) {
await this.getStageTickets(stage);
}
},
async getStageTickets(stage) {
const tickets = ["a", "b", "c"];
for (let ticket of tickets) {
this.stages[this.stages.indexOf(stage)].tickets.push(ticket);
}
},
},
mounted() {
this.getTeamStages();
},
};
</script>
It should be noted that I used the concat method of an array object and also works:
this.stages[this.stages.indexOf(stage)].tickets = this.stages[this.stages.indexOf(stage)].tickets.concat(tickets);
I tried your approaches some of them work correctly:
NOT WORKED
this.$set(this.stages[this.stages.indexOf(stage)].tickets, tickets)
WORKED
this.$set(this.stages[this.stages.indexOf(stage)].tickets, 0, tickets[0]);
WORKED
stage.tickets = tickets
this.stages.splice(this.stages.indexOf(stage), 1, stage)
I'm sure it is XY problem..
A possible solution would be to watch the selected team and load the values from there. You seem to be loading everything from the mounted() hook, and I suspect this won't actually load all the content on demand as you'd expect.
I managed to make it work here without needing to resort to $set magic, just the pure old traditional vue magic. Vue will notice the properties of new objects and automatically make then reactive, so if you assign to them later, everything will respond accordingly.
My setup was something like this (showing just the relevant parts) -- typing from memory here, beware of typos:
data(){
teams: [],
teamId: null,
team: null
},
watch:{
teamId(v){
this.refreshTeam(v)
}
},
methods: {
async refreshTeam(id){
let team = await fetchTeam(id)
if(!team) return
//here, vue will auomaticlly make this.team.stages reactive
this.team = {stages:[], ...team}
let stages = await fetchStages(team.id)
if(!stages) return
//since this.team.stages is reactive, vue will update reactivelly
//turning the {tickets} property of each stage reactive also
this.team.stages = stages.map(v => ({tickets:[], ...v}))
for(let stage of this.team.stages){
let tickets = await fetchTickets(stage.id)
if(!tickets) continue
//since tickets is reactive, vue will update it accordingly
stage.tickets = tickets
}
}
},
async mounted(){
this.teams = fetchTeams()
}
Notice that my 'fetchXXX' methods would just return the data retrieved from the server, without trying to actually set the component data
Edit: typos
OK, say I have an initial state in our Redux store that looks like this:
const initialState = {
userReports: [],
activeReport: null,
}
userReports is a list of reports. activeReport is one of those reports (the one that is actively being worked with).
I want the active report to point to one in the array. In other words, if I modify the active report, it would modify one in the userReports array. This means, the two objects must point to the same memory space. That's easy to set up.
The alternative to this approach would be to copy one of the reports that is in the userReports array and set it as the active report (now it has a different memory address). The problem is now, when I edit the activeReport, I also have to search through the array of userReports, find the report that resembles the active report and modify it there too. This feels verbose.
Here is the question:
Would it be bad practice to have the activeReport point to a report in the array (same object). When I want to change the report I could do something like this (example is using redux thunk):
export const updateReport = (report) => async (dispatch, getState) => {
try {
const report = getState().reports.activeReport
// modify the active report here
report.title = "blah blah blah"
dispatch({ type: ACTIONS.UPDATE_REPORT, payload: report })
} catch (error) {
console.log(`ERROR: ${error.message}`)
}
}
And in my reducer:
case ACTIONS.UPDATE_REPORT:
return { ...state, activeReport: action.payload }
as you can see, after updating the report I still return a "new version" of that report and set it as active, but this approach also updates the report in the userReports array because they point to the same memory address.
I would say thats not ideal, do the reports have id's? If they do I would rather hold the userReports in an object with keys being the id's, then active report can just be an id and renamed to activeReportId so you can fetch the activeReport with userReports[activeReportId]
You also asked for reasons:
So firstly any screen that looks at userReports wont rerender because the reports aren't being reassigned.
Secondly if someone later wants to update those screens they will reassign userReports which could cause problems.
Thirdly its an unusual pattern which is a huge no no for redux. The point of redux is that it has a very obvious pattern so when you add things to it you don't have to think and can just make changes with confidence.
Your activeReport should not be pointing to an object in the userReports array, but rather it should be an id of the report, which the user is currently working on. Each of the report in the userReports will have a unique id field to identify the report - this would be helpful when rendering in react - this id field can be used as key.
Then your action creator/dispatcher will look like this:
export const updateReport = (updatedReport) => async (dispatch, getState) => {
dispatch({ type: ACTIONS.UPDATE_REPORT, payload: updatedReport });
}
You will call this on change in your component:
const onTitleChangeHandler = (e) => {
var newTitle = e.target.value;
// you will get the userReports and activeReport from props or by using some redux selector, also you will need to get dispatch and getState from redux
var activeReportObj = userReports.filter((r) => r.id === activeReport)[0];
updateReport({ title: newTitle, ...activeReportObj })(dispatch, getState);
}
Lastly, your reducer will be:
case ACTIONS.UPDATE_REPORT:
var newUserReports = state.userReports.map((r) => {
if (r.id === state.activeReport) {
return action.payload;
}
return r;
});
return { newUserReports, ...state };
I am working with Nuxt and Vue, with MySQL database, all of which are new to me. I am transitioning out of WebMatrix, where I had a single Admin page for multiple tables, with dropdowns for selecting a particular option. On this page, I could elect to add, edit or delete the selected option, say a composer or music piece. Here is some code for just 2 of the tables (gets a runtime error of module build failed):
<script>
export default {
async asyncData(context) {
let [{arrangers}, {composers}] = await Promise.all([
context.$axios.get(`/api/arrangers`),
context.$axios.get(`/api/composers`),
])
const {arrangers} = await context.$axios.get('/api/arrangers')
const {composers} = await context.$axios.get('/api/composers')
return { arrangers, composers }
},
}
</script>
You do have the same variable name for both the input (left part of Promise.all) and as the result from your axios call, to avoid naming collision, you can rename the result and return this:
const { arrangers: fetchedArrangers } = await context.$axios.get('/api/arrangers')
const { composers: fetchedComposers } = await context.$axios.get('/api/composers')
return { fetchedArrangers, fetchedComposers }
EDIT, this is how I'd write it
async asyncData({ $axios }) {
const [posts, comments] = await Promise.all([
$axios.$get('https://jsonplaceholder.typicode.com/posts'),
$axios.$get('https://jsonplaceholder.typicode.com/comments'),
])
console.log('posts', posts)
console.log('comments', comments)
return { posts, comments }
},
When you destructure at the end of the result of a Promise.all, you need to destructure depending of the result that you'll get from the API. Usually, you do have data, so { arrangers } or { composers } will usually not work. Of course, it depends of your own API and if you return this type of data.
Since destructuring 2 data is not doable, it's better to simply use array destructuring. This way, it will return the object with a data array inside of it.
To directly have access to the data, you can use the $get shortcut, which comes handy in our case. Directly destructuring $axios is a nice to have too, will remove the dispensable context.
In my example, I've used JSONplaceholder to have a classic API behavior (especially the data part) but it can work like this with any API.
Here is the end result.
Also, this is what happens if you simply use this.$axios.get: you will have the famous data that you will need to access to later on (.data) at some point to only use the useful part of the API's response. That's why I do love the $get shortcut, goes to the point faster.
PS: all of this is possible because Promise.all preserve the order of the calls: https://stackoverflow.com/a/28066851/8816585
EDIT2: an example on how to make it more flexible could be
async asyncData({ $axios }) {
const urlEndpointsToFetchFrom = ['comments', 'photos', 'albums', 'todos', 'posts']
const allResponses = await Promise.all(
urlEndpointsToFetchFrom.map((url) => $axios.$get(`https://jsonplaceholder.typicode.com/${url}`)),
)
const [comments, photos, albums, todos, posts] = allResponses
return { comments, photos, albums, todos, posts }
},
Of course, preserving the order in the array destructuring is important. It's maybe doable in a dynamic way but I don't know how tbh.
Also, I cannot recommend enough to also try the fetch() hook alternative someday. I found it more flexible and it does have a nice $fetchState.pending helper, more here: https://nuxtjs.org/blog/understanding-how-fetch-works-in-nuxt-2-12/ and in the article on the bottom of the page.
What I try to do
I have an app which should work offline.
There is an Item-list. I can add an Item to this list with a mutation.
The update function of the mutation adds the Item to the Item-list. (Optimistic Response)
When I click on an Item, I want to see the details.
My Implementation
Content of Mutation update function:
const queryData = cache.readQuery<{ items: Item[] }>({
query: MY_QUERY,
variables: {
filter
}
});
if (!queryData?.items) {
return;
}
const newData = [...queryData.items, newItem];
cache.writeQuery({
query: MY_QUERY,
data: { items: newData },
variables: {
filter
}
});
Get details of the item in the vue-file:
apolloProvider.clients.defaultClient
.readFragment<Item>({
fragment: ITEM_FRAGMENT,
id:id
});
The problem
Adding the item to the Query-result works fine.
When I try to read the fragment:
I get null for items which were added by the Mutation update function
I get the expected object for items which were fetched from the backend
There is also the optimistic attribute in readFragment, but that doesn't make a difference.
Other observations
When I write and immediately read the fragment in the Mutation update function, I am able to get it.
cache.writeFragment({
fragment: ITEM_FRAGMENT,
data: item,
id: item._id,
});
const data = cache.readFragment({
fragment: ITEM_FRAGMENT,
id: item._id,
});
console.log({ data }); // This logs my item Object
Package versions:
{
"#nuxtjs/apollo": "^4.0.1-rc.3",
"apollo-cache-persist": "^0.1.1",
"nuxt": "^2.0.0",
}
Summary
apollo.readFragement doesn't work for values from an optimistic response.
Maybe someone here has an idea of what I am missing, or a different approach to implement this functionality
To get optimistic values from apollo cache you need to add true as second parameter in your readFragment call.
readFragment(options, optimistic)
(optimistic is false by default.)
In your case:
apolloProvider.clients.defaultClient
.readFragment<Item>({
fragment: ITEM_FRAGMENT,
id:id
}, true);
When creating an optimistic response for a resource that is in the process of being created via a mutation (e.g. your item), we need to assign some kind of temporary id to the optimistic data (see example in the docs). This is because the real resource hasn’t been created yet and we don’t know it’s id.
Given this, to read the optimistic response from the cache we need to use that same temporary id (as well as the __typename). When the mutation completes and we have the real response in the cache the optimistic response is discarded and we can use the real id.
I ran into this recently as I was assigning a temporary id, but not using it to retrieve the optimistic response from the cache to render the updated UI in that brief window where I was waiting for the mutation to complete.
I am developing a CRUD application to show user-list. As an admin, the user list is shown with edit & delete icons. Once the user is deleted by dispatching deleteUser action, the user-list should be re-fetched to reflect updated list of users.
actions: {
fetchUsers(context) {
axios.get("/get/user").then(function(response) {
context.commit("SET_USERS", response.data);
});
},
deleteUser(context,payload) {
axios.delete("/delete/user",).then(function(response) {
if(response.status == 200) {
//Refresh the user list.
//HOW TO call "fetchUsers" from here.?
}
})
}
}
So I need to call fetchUsers action after delete user successful.
What is the best way to achieve this? Copying the code would help but it's against DRY principle. Delete is an example but there could be several actions like edit which would need to call fetchUsers again.
Kindly provide inputs.
Regards
Robin.
You seem to be missing a critical feature of Vuex which is actions. If you need to perform an async operation regarding a mutation, the async operations should be performed from an action. Within the action, you'll be able to perform other actions, as this answer shows.
You can use the dispatch() of the context object like this
deleteUser(context,payload) {
axios.delete("/delete/user",).then(function(response) {
if(response.status == 200) {
// payload is optional and used if you want to send specific datas to your fetchUsers method
context.dispatch('fetchUsers', payload)
}
})
}
cf: https://vuex.vuejs.org/api/#commit and https://vuex.vuejs.org/api/#actions