嵌套GraphQL解析器未调用

时间:2020-08-04 22:18:42

标签: graphql sequelize.js

我的GraphQL / Sequelize源代码有另一个问题。似乎在运行时未使用我的解析器。当前,似乎为顶部输出类型(Page)调用了解析器,但似乎没有为第二种输出类型(Content)调用了解析器。

前端发送的查询:

query {
    pages (hidden: false) { // this resolver is called (Page)
        id
        label
        paragraphs (hidden: false) { // but not this one... (Content)
            id
            heading
            text
        }
    }
}

查询包定义:

import pageFields from './fields/page';
import contentFields from './fields/content';

const QueryBundle = new GraphQLObjectType({
    name: 'Query',
    description: 'This is the root query',
    fields: () => {
        return {
            pages: pageFields,
            paragraphs: contentFields
        };
    }
});

pageFields文件:

import Page from '../types/page';
import PageParagraph from '../inputs/content';
import db from '../db';

// This is the Page's fields for the QueryBundle definition...
const pageFields = {
    type: new GraphQLList(Page),
    args: {
        id: {
            type: GraphQLInt
        },
        label: {
            type: GraphQLString
        },
        hidden: {
            type: GraphQLBoolean
        },
        paragraphs: {
            type: new GraphQLList(PageParagraph)
        }
    },
    async resolve(parent, args) {
        return await db.models.page.findAll({
            include: [{
                all: true,
                nested: true
            }],
            where: args
        });
    }
};

export default pageFields;

注意:此解析器将被调用,GraphiQL工具和终端都将显示SELECT查询...

contentFields文件:

import Content from '../types/content';
import db from '../db';

// This is the Content's fields for the QueryBundle definition...
const contentFields = {
    type: new GraphQLList(Content),
    args: {
        id: {
            type: GraphQLInt
        },
        heading: {
            type: GraphQLString
        },
        text: {
            type: GraphQLString
        },
        hidden: {
            type: GraphQLBoolean
        }
    },
    async resolve(parent, args) {
        return await db.models.content.findAll({
            include: [{
                all: true,
                nested: true
            }],
            where: args
        });
    }
};

export default contentFields;

注意:但是这个从来没有被调用过,为什么呢?我在查询中使用的所有参数都将被忽略,因为它永远不会到达这一点...

解决方案:

...

// This is the Sequelize model definition (output type) of the Page table...
const Page = new GraphQLObjectType({
    name: 'Page',
    description: 'This represents a Page',
    fields: () => {
        return {
            id: {
                type: GraphQLInt,
                resolve(page) {
                    return page.id;
                }
            },
            ...
            paragraphs: {
                args: {// <== This is new! Here we add the arguments...
                    hidden: {
                        type: GraphQLBoolean
                    },
                    box: {
                        type: GraphQLBoolean
                    }
                },
                type: new GraphQLList(Paragraph), // <== Unchanged
                resolve(parent, args, {pagesParagraphsLoader}, info) {// <== This is new! Here we needed a resolver for the OUTPUT type... Same goes for every nested type...
                    const data = {
                        id: parent.id,
                        args: args
                    };
                    return pagesParagraphsLoader.load(data);
                }
            }
        };
    }
});

export default Page;

Github及其所有有效更改:goldenmaza's Github

1 个答案:

答案 0 :(得分:1)

如果带有pageFields的{​​{1}}解析器返回nested:true,则此属性已被解析。

无需单独调用它,它的解析器被跳过,而不被调用。

这种解析器行为用于优化,当调用多个子对象(一个单独的DB请求一个一个地调用)时,父对象中的过度获取将无效。

删除paragraphs或基于顶级nested:true arg实施附加过滤(如果隐藏在page == hidden中)。通常,在顶级查询级别构建/使用的复杂(生成的)过滤器可以声明嵌套子项的条件。