Multiple Queries/Mutation in Apollo 2.1 - graphql

I need some help using the new Query and Mutation component in Apollo 2.1, especially with multiple queries and mutations.
I have the following problems:
I have a graphql request that depends on a previous graphql result, how can I deal with this?
How do I add two different mutations (in my component I need to do two different actions) in a component that already has a query?

edit 2019/08/24
from the Apollo docs:
The new hooks API for Apollo Client is a simpler way to fetch data in
your React app without the boilerplate of render prop components and
higher-order components (HOC). We recommend using hooks for all new
Apollo code going forward.
original answer:
You are supposed to nest them. See this example:
const NumbersWithData = () => (
<Query query={QueryOne}>
{({ loading: loadingOne, data: { one } }) => (
<Query query={QueryTwo}>
{({ loading: loadingTwo, data: { two }}) => {
if (loadingOne || loadingTwo) return <span>loading...</span>
return <h3>{one} is less than {two}</h3>
}}
</Query>
)}
</Query>
);
To help with keeping the nesting manageable, you could check react-adopt. They have an Apollo ToDo App example, where they combine a Query and multiple Mutations.

For this purpose react-apollo exports a compose function. Using this function you may cleanly use several component enhancers at once. Including multiple graphql(), or even Redux connect() enhancers.
import { Mutation, compose, graphql } from "react-apollo";
class AddTweet extends Component {
....
....
....
}
export default compose(
graphql(GET_AUTHORS, { name: "getAuthors" }),
graphql(ADD_TWEET, { name: "addTweet" }),
connect(...), // incase you are using Redux
)(AddTweet);
An important note is that compose() executes the last enhancer first and works its way backwards through the list of enhancers.
One more thing lets say you were using this.props.data now you will get get undefined. just console.log(this.props) and you will see what is happening to props now. You will be having two properties now getAuthors and addTweet. So now it will be this.props.name-in-compose.name-of-type-in-typeDefs i.e. this.props.getAuthors.getUsers. It took me a bit to figure it out.

In my opinion,
To make a request depends on previous request, you can break that request to children component and pass result of previous request like props to it and do that request.
To use more than one mutation and queries, you can use compose like this
...
#compose(
graphql(GET_FEEDS_QUERY, {name : 'getFeeds'}),
graphql(CREATE_NEW_POST, {name: "createNewPost"}),
graphql(LIKE_POST_MUTATION, { name: "unlikePostMutation"}),
...
)
class HomeScreen extends Component {
...
}

I wrote a Medium Post about how to combine Mutation and Query on the same Component.
Here is a snippet from the post
// other import
import {Query} from “Apollo-graphql”; // new Query Component
import gql from "graphql-tag";
import { graphql } from "react-apollo";
import UserComponent from '../component/UserComponent'; // any component to display query result
const GET_ALL_USER = gql`
{
allUsers: {
firstname,
lastname,
username,
# other information
}
}
`
const UPDATE_USER_STATUS = gql`
mutation UpdateUserStatus($userID: ID!, $status: Int!){
updateUserState(userID: $userID, status: $status){
firstname,
lastname
username
# other information
}
}
`
ExampleComponent extends React.Component{
onEditInformation = async (user) => {
const response = await mutate({
variables: {userID: user}
})
}
render(){
return(
<Query query={GET_ALL_USER}>
{({data: { allUsers }}) => {
return allusers.map(user => {
return (
<UserComponent
user={user}
onEdit={() => this.onEditInformation(user)}
/>
)
})
}}
</Query>
)
}
}
export default graphql(UPDATE_USER_STATUS)(ExampleComponent);

Asides from using compose from react-apollo, another great utility library you can check it out is react-adopt. A great small utility lib that helps you to compose multiple render props type components so you don't have a nested hell patterns.
I have wrote a similar answer that basically covers all your current needs in terms of:
How to consume a previous result from your mapper fn via react-adopt
Combine multiple Query/Mutations from Composed component via react-adopt
Here's the detailed answer you're looking for & hopefully can be helpful to solving your problems :)

Best solution for this
Simply nest graphql function
export default graphql(addBookMutation)(graphql(getAuthorsQuery)(AddBook))
You can refer to this
Apollo concepts

Related

How to build a Model Layer in Vue3 just like other MVC language?

my name is DP, I have 2 years Vue2 experience, but I am new to Vue3. I am learning Vue3 recently, as I found the "setup(Composition API)" just like the "Controller(in MVC)" that I did in other language, so I am trying to build my test Vue3 project in MVC way, but I go some problem can anyone help? thx!
MVC Plan
M - use class
V - use <template> ... </template>
C - use setup
My Problem
working: using loadTopic_inSetup().then() in setup is working, because topicList_inSetup is defined in setup() too.
not working: using loadTopic_inModel() in setup is not working, I guess some kind data keep problem, because in console I can see the data already got from API
as u can see, I am not expert for js/ts, I am a backend developer, so if you know how to do it, plz help thx very much.
BTW, VUE is greet, I love it.
My Code
//APIBased.ts
import { ajax } from "#/lib/eeAxios"
export class APIBased {
//load data with given url and params
loadData(apiPath: string, params?: object): Promise<any> {
apiPath = '/v1/'+apiPath
return ajax.get(apiPath, params)
}
}
//Topic.ts
import { APIBased } from "./APIBased";
import { ref } from 'vue'
export class Topic extends APIBased {
//try keep data in model
topicList: any = ref([]);
constructor() {
super()
}
//direct return ajax.get, let setup do the then+catch
loadTopic_inSetup() {
return super.loadData('topics', { t_type_id: 1 })
}
//run ajax get set return data to this.topicList, keep data in model
loadTopic_inModel() {
super.loadData('topics', { t_type_id: 1 }).then((re) => {
console.log(re.data)
this.topicList = re.data
})
}
}
//EETest.vue
<template>
<EELayoutMainLayout>
<template v-slot:mainContent>
<h1>{{ "Hello Vue3 !!" }}</h1>
<hr/>
{{to.topicList}} //not working... just empty array
<hr/>
{{topicList_inSetup}} //working... topic list return from API show here.
</template>
</EELayoutMainLayout>
</template>
<script lang="ts">
import { defineComponent, getCurrentInstance, ref } from 'vue'
import EELayoutMainLayout from '#/components/eeLayout/EELayoutMainLayout.vue'
import { Topic } from "#/models/Topic";
export default defineComponent({
name: 'EETest',
props: {
},
setup() {
let topicList_inSetup = ref([])
const to = new Topic()
//try keep data in setup, it's working
to.loadTopic_inSetup().then((re) => {
topicList_inSetup.value = re.data
console.log(re.data)
})
//try keep data in model, the function is run, api return get, but data not show, even add ref in model
to.loadTopic_inModel()
return {
topicList,
to,
}
},
components: {
EELayoutMainLayout,
},
})
</script>
A few digressions before solving the problem. Maybe you are a java developer. I personally think it is inappropriate to write the front end with Java ideas. The design of vue3's setup is more inclined to combined functional programming
To fully understand why you need some pre knowledge, Proxy and the get and set method of Object
They correspond to the two core apis in vue, reactive and ref,
The former can only be applied to objects( because proxy can only proxy objects),The latter can be applied to any type(primary for basic javascript types, get and set can apply for any type)
You can modify the code to meet your expectations
loadTopic_inModel() {
super.loadData('topics', { t_type_id: 1 }).then((re) => {
console.log(re.data)
this.topicList.value = re.data
})
}
You cannot modify a ref object directly, a test case to explain what is reactive
when ref function is called, a will be like be wrapped in a class has value properties, and has get and set method
the effect function will call the arrow function, and in this time, the get method of a will be called and it will track as a dependence of the effect function, when a changed, the set method of a will be called, and it will trigger the arrow function,
so when you direct modify the a, the setter method will never trigger, the view will not update
const a = ref(1)
let dummy
let calls = 0
effect(() => {
calls++
dummy = a.value
})
expect(calls).toBe(1)
expect(dummy).toBe(1)
a.value = 2
expect(calls).toBe(2)
expect(dummy).toBe(2)
// same value should not trigger
a.value = 2
expect(calls).toBe(2)

Apollo GraphQL - How do I use an RxJS Subject as a variable with Apollo Client?

My type-ahead search was working great with REST but I'm converting to GraphQL, which has its challenges.
As the user types a last name into a form field the suggested results display in a data table below. Each letter is handled by the RxJS Subject.
The var searchTerm$ is a type of RXJS observable called a Subject binds to the HTML. The following is called from the OnViewInit lifecycle hook in an Angular app. The search is by the database column last_name.
However, this results in a Bad Request 400 error as the view loads and search doesn't work. I thought maybe this calls for a subscription but everything I find on those is about using web sockets to connect to a remote URL and server. Where do I go from here?
I'm using the Angular Apollo client with Apollo Express but I would be happy with any JS solution and try to figure it out from there. The server side is Nestjs which just wraps Apollo Server.
const lastNameSearch = gql `
query ($input: String!) {
lastNameSearch(input: $input) {
first_name
last_name
user_name
pitch
main_skill_title
skills_comments
member_status
}
}`;
this.apollo
.watchQuery({
query: lastNameSearch,
variables: {
last_name: searchTerm$, // Trying to use the observable here.
},
})
.valueChanges
.subscribe(result => {
console.log('data in lastNameSearch: ', result);
}),
The schema on the server:
lastNameSearch(input: String!): [Member]
The resolver:
#Query()
async lastNameSearch(#Args('input') input: String) {
const response = await this.membersService.lastNameSearch(input);
return await response;
}
Edit:
The error from the Network panel in dev tools. Console message worthless.
{"errors":[{"message":"Variable \"$input\" of required type \"String!\" was not provided.","locations":[{"line":1,"column":8}],"extensions":{"code":"INTERNAL_SERVER_ERROR","exception":{"stacktrace":["GraphQLError: Variable \"$input\" of required type \"String!\" was not provided."," at getVariableValues
And this goes on showing properties and methods in the app for another 300 lines or so.
First, a big thank you to the amazing Daniel Rearden for his help on various questions as I and lots of others on SO learn GraphQL! He has patience!
As Daniel pointed out in comments I had a simple mistake. I'll point it out in the commented code below. However, the big issue was trying to use an observable, subject, or similar method as a variable. Even if the RxJS subject is emitting a string GraphQL will hate trying to use a large object as a var. So I had to use a little reactive programming to solve this.
Setup the observable:
public searchTerm$ = new Subject<string>(); // Binds to the html text box element.
Second, let's set this up in a lifecycle hook where we subscribe to the observable so it will emit letters one at a time as they are typed into an input box.
ngAfterViewInit() {
let nextLetter: string;
// -------- For Last Name Incremental Query --------- //
this.searchTerm$.subscribe(result => {
nextLetter = result; // Setup a normal variable.
this.queryLastName(nextLetter); // Call the GraphQL query below.
});
}
Last step we have the GraphQL query and consuming the returned data object. This works perfect to say type a 'p' into the form and get back from a db all the last names starting with 'p' or 'P'. Type 'r' and the results narrow to last names starting with 'pr', and so on.
private queryLastName(nextLetter) {
const lastNameSearch = gql`
query ($input: String!) {
lastNameSearch(input: $input) {
first_name
last_name
user_name
pitch
main_skill_title
skills_comments
member_status
}
}`;
this.apollo
.watchQuery({
query: lastNameSearch,
variables: {
input: nextLetter, // Notice I had used last_name here instead of input.
},
})
.valueChanges
.subscribe(result => {
// Put the data into some UI in your app, in this case
// an Angular Material data table.
// Notice how we get the data from the returning object.
// The avoids the dreaded "null" error when the shape of the
// returned data doesn't match the query. This put an array
// of objects into the UI.
this.dataSource.data = result.data['lastNameSearch'];
},
);
}

Can you request a literal value in graphql?

I'm trying to figure out how to mock requests when the client is ahead of the server. I'd like to be able to just request literals so that I can go back and change them later, is there a way to do something like this?
query myQuery {
type {
fieldName: 42
}
}
Yes, it is quite easy to set up mock responses if you have at least the server boilerplate code set up. If you are using Apollo, there are built in tools to facilitate mocks.
https://www.apollographql.com/docs/graphql-tools/mocking.html
From the docs:
The strongly-typed nature of a GraphQL API lends itself extremely well
to mocking. This is an important part of a GraphQL-First development
process, because it enables frontend developers to build out UI
components and features without having to wait for a backend
implementation.
Here is an example from the docs:
import { makeExecutableSchema, addMockFunctionsToSchema } from 'graphql-tools';
import { graphql } from 'graphql';
// Fill this in with the schema string
const schemaString = `...`;
// Make a GraphQL schema with no resolvers
const schema = makeExecutableSchema({ typeDefs: schemaString });
// Add mocks, modifies schema in place
addMockFunctionsToSchema({ schema });
const query = `
query tasksForUser {
user(id: 6) { id, name }
}
`;
graphql(schema, query).then((result) => console.log('Got result', result));
This mocking logic simply looks at your schema and makes sure to
return a string where your schema has a string, a number for a number,
etc. So you can already get the right shape of result. But if you want
to use the mocks to do sophisticated testing, you will likely want to
customize them to your particular data model.

how to wait a graphql query is finished using apollo?

I have the following code :
ngOnInit() {
this.data = this.apollo.query({ query: ResidentQuery }).subscribe(({data, loading}) => {
this.data = data;
this.loading = loading;
});
if (!this.loading) {
// using this.data
}
}
I want data to be loaded before processed themm after the (!this.loading). It is not the case as loading is asynchronous. How I can wait the data is loaded before using them ?
I am making a graphql query using apollo client. ResidentQuery is a string containing the graphql query.
Thank you for your feedbacks !
I'm not sure how angular works, but I know how it works in react and I know the two are similar.
In react, you need to use componentWillReceiveProps() (EDIT: Now Deprecated), for example:
componentWillReceiveProps(newProps){
if(!newProps.query.loading){
this.setState({data: newProps.query.data})
}
}
From the medium article for how angular and react lifecycles are similar
Basically, the props will be bind automatically by Angular, so I
suppose the setter and getter function will be that part, which gives
you a way to generate complex state or variable, like what you can do
in componentWillReceiveProps().

React-native / Redux - error with state

So far I have been following various tutorials. This time I'm trying to build things from scratch (kind of). For now the following is supposed to display part of state. Later on I'll play with making it do calculations,etc. Still I get an error:
Cannot read property 'count' of undefined
So I use mapStateToProps and the first step I'd like to do is to get it to display this.props.count and this.props.step. Once I've done it I'll modify it to do more complex things.
Here's the component and below there's a link to the whole code that I put on github.
import React, { Component } from 'react';
import { View, Text } from 'react-native';
import { connect } from 'react-redux';
import { getCounter } from '../actions';
class CounterBoard extends Component {
render() {
return (
<View>
<Text>BELOW SHOULD DISPLAY 0</Text>
<Text>{this.prop.count}</Text>
</View>
);
}
}
const mapStateToProps = (state) => {
return {
count: state.count,
step: state.step
};
};
export default connect(mapStateToProps, { getCounter })(CounterBoard);
https://github.com/wastelandtime/calculator
Edit: Thank you for the 'prop' => 'props' pointer. Now I have the following error:
ExceptionsManager.js:63 Objects are not valid as a React child (found: object with keys {count, step}). If you meant to render a collection of children, use an array instead or wrap the object using createFragment(object) from the React add-ons. Check the render method of `Text`.
After going through your code on Github, I couldn't help but notice that in your action, you return the following object:
export const getCounter = (count) => {
return {
type: GET_COUNTER,
payload: count
};
};
If you intend to return the count, I assume that action.payload should contain a number here and not an object.
However, in your reducer, you return:
case GET_COUNTER:
return action.payload.count;
Assuming from the code in your CounterBoard Component and CalcReducer, you probably wanted to merge your payload into the initial state before returning from the reducer?
You might also need to pass and argument while dispatching the getCounter action, for the component to work as expected.

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