【发布时间】:2019-04-25 16:38:51
【问题描述】:
我正在尝试 Apollo 分页。如果我没有从客户端传递限制参数并在我的hasMoreData 函数中硬编码限制参数,它会正常工作。如果我要添加限制参数,所有数据都将从我的服务器返回,并且不会分页。服务器端代码应该是正确的(我在 GraphQL 操场上测试过)。
这不能正常工作:
import React, { Component } from "react";
import {
View,
Text,
ActivityIndicator,
FlatList,
Button,
StyleSheet
} from "react-native";
import { graphql } from "react-apollo";
import gql from "graphql-tag";
let picturesList = [];
class HomeScreen extends Component {
loadMore = () => {
this.props.data.fetchMore({
variables: {
offset: picturesList.length
},
updateQuery: (prev, { fetchMoreResult }) => {
if (!fetchMoreResult) {
return prev;
}
return {
...prev,
pictures: [...prev.pictures, ...fetchMoreResult.pictures]
};
}
});
};
render() {
const { loading, pictures, variables } = this.props.data;
picturesList = pictures;
if (loading) {
return <ActivityIndicator size="large" />;
}
//TODO - hard coded the limit as 3 which is not supposed to
let hasMoreData = picturesList.length % 3 === 0;
if (picturesList.length <= variables.offset) {
hasMoreData = false;
}
return (
<View style={styles.root}>
<Button title="Show More" onPress={this.loadMore} />
<FlatList
data={picturesList}
renderItem={({ item }) => (
<View style={styles.contentContainer}>
<Text style={styles.content}>{item.title}</Text>
</View>
)}
keyExtractor={item => item.id}
ListFooterComponent={() =>
hasMoreData ? (
<ActivityIndicator size="large" color="blue" />
) : (
<View />
)
}
/>
</View>
);
}
}
const styles = StyleSheet.create({
root: {
flex: 1
},
content: {
fontSize: 35
},
contentContainer: {
padding: 30
}
});
// adding the limit variable here will cause my server to return all data
const PICTURES_QUERY = gql`
query($offset: Int, $limit: Int) {
pictures(offset: $offset, limit: $limit) {
id
title
pictureUrl
}
}
`;
export default graphql(PICTURES_QUERY)(HomeScreen);
服务端代码,以防万一:
pictures: async (_, { offset, limit }) => {
let picturesDB = getConnection()
.getRepository(Picture)
.createQueryBuilder("p");
return picturesDB
.take(limit)
.skip(offset)
.getMany();
}
我在我的 GraphQL 架构中添加了一个默认参数:
type Query {
pictures(offset: Int, limit: Int = 3): [Picture!]!
}
【问题讨论】:
标签: react-native graphql react-apollo