GraphQL returning all children from a structure when requesting multiple entry types (3.4.0-RC3)

[samput]

Description

Using Craft CMS version 3.4.0-RC3. When querying children by type from a structure with GraphQL it returns all children when requesting multiple types.

Steps to reproduce

I have a section 'Pipeline' with a structure set up like so:

- Quarter (entryType: quarter)
    - Platform (entryType: platform)
        - Ongoing (entryType: ongoing)
        - Monthly (entryType: monthly)

GraphQL query - multiple children types:

{
  quarters: entries (section: "pipeline", type: "quarter") {
    id
    title
    platforms: children (type: "platform") {
      id
      title
      ongoing: children (type:"ongoing") {
        id
        title
      }
      monthly: children (type:"monthly") {
        id
        title
      }
    }
  }
}

Response - multiple children types:
For both ongoing and monthly it returns all the children.

{
  "data": {
    "quarters": [
      {
        "id": "14",
        "title": "Q1 2020",
        "platforms": [
          {
            "id": "136",
            "title": "Platform Name",
            "ongoing": [
              {
                "id": "155",
                "title": "Q1 2020 - Platform Name - Ongoing"
              },
              {
                "id": "158",
                "title": "Q1 2020 - Platform Name - January"
              },
              {
                "id": "161",
                "title": "Q1 2020 - Platform Name - February"
              },
              {
                "id": "164",
                "title": "Q1 2020 - Platform Name - March"
              }
            ],
            "monthly": [
              {
                "id": "155",
                "title": "Q1 2020 - Platform Name - Ongoing"
              },
              {
                "id": "158",
                "title": "Q1 2020 - Platform Name - January"
              },
              {
                "id": "161",
                "title": "Q1 2020 - Platform Name - February"
              },
              {
                "id": "164",
                "title": "Q1 2020 - Platform Name - March"
              }
            ]
          }
        ]
      },
      {
        "id": "17",
        "title": "Q2 2020",
        "platforms": []
      },
      {
        "id": "20",
        "title": "Q3 2020",
        "platforms": []
      },
      {
        "id": "23",
        "title": "Q4 2020",
        "platforms": []
      }
    ]
  }
}

However if I only request one child type, it works as expected e.g.

GraphQL query - ongoing children type:

{
  quarters: entries (section: "pipeline", type: "quarter") {
    id
    title
    platforms: children (type: "platform") {
      id
      title
      ongoing: children (type:"ongoing") {
        id
        title
      }
    }
  }
}

Response - ongoing children type:

{
  "data": {
    "quarters": [
      {
        "id": "14",
        "title": "Q1 2020",
        "platforms": [
          {
            "id": "136",
            "title": "Platform Name",
            "ongoing": [
              {
                "id": "155",
                "title": "Q1 2020 - Platform Name - Ongoing"
              }
            ]
          }
        ]
      },
      {
        "id": "17",
        "title": "Q2 2020",
        "platforms": []
      },
      {
        "id": "20",
        "title": "Q3 2020",
        "platforms": []
      },
      {
        "id": "23",
        "title": "Q4 2020",
        "platforms": []
      }
    ]
  }
}

GraphQL query - monthly children type:

{
  quarters: entries (section: "pipeline", type: "quarter") {
    id
    title
    platforms: children (type: "platform") {
      id
      title
      monthly: children (type:"monthly") {
        id
        title
      }
    }
  }
}

Response - monthly children type:

{
  "data": {
    "quarters": [
      {
        "id": "14",
        "title": "Q1 2020",
        "platforms": [
          {
            "id": "136",
            "title": "Platform Name",
            "monthly": [
              {
                "id": "158",
                "title": "Q1 2020 - Platform Name - January"
              },
              {
                "id": "161",
                "title": "Q1 2020 - Platform Name - February"
              },
              {
                "id": "164",
                "title": "Q1 2020 - Platform Name - March"
              }
            ]
          }
        ]
      },
      {
        "id": "17",
        "title": "Q2 2020",
        "platforms": []
      },
      {
        "id": "20",
        "title": "Q3 2020",
        "platforms": []
      },
      {
        "id": "23",
        "title": "Q4 2020",
        "platforms": []
      }
    ]
  }
}

Additional info

• Craft version: 3.4.0-RC3
• PHP version: 7.3.11
• Database driver & version: MySQL 5.7.24
• Plugins & versions: Feed Me 4.2.0.1, Redactor 2.5.0

[andris-sevcenko]

The issue occurs because children is not a real field as far as Craft custom fields go, but rather a construct created for eager-loading.

For example, if it were an entry field or a matrix field, this would work because internally relational fields resolve to be element queries so that you can apply more parameters to them.

There was a similar issue for Matrix fields (#5008), which looks the same as your problem, but it cannot be solved the same way.

As most GraphQL querying issues, this dead-ends sinceGraphQL is wrapping around element queries, so is often limited by the element query's features.

The best approach here would be if Craft itself had a concept of alias in element queries, which is an issue I'll bring up internally and then update this issue.

[andris-sevcenko]

@samput it's still possible, however, to fetch all the children and then just differentiate or sort the data on the frontend.

For example:

{
  quarters: entries(section: "pipeline", type: "quarter") {
    id
    title
    platforms: children {
      id
      title
      children {
        __typename
        id
        title
      }
    }
  }
}

would produce

{
  "data": {
    "quarters": [{
        "id": "14",
        "title": "Q1 2020",
        "platforms": [{
          "id": "136",
          "title": "Platform Name",
          "children": [{
              "__typename": "pipelineSection_ongoing_Entry",
              "id": "155",
              "title": "Q1 2020 - Platform Name - Ongoing"
            },
            {
              "__typename": "pipelineSection_monthly_Entry",
              "id": "158",
              "title": "Q1 2020 - Platform Name - January"
            },
            {
              "__typename": "pipelineSection_monthly_Entry",
              "id": "161",
              "title": "Q1 2020 - Platform Name - February"
            },
            {
              "__typename": "pipelineSection_monthly_Entry",
              "id": "164",
              "title": "Q1 2020 - Platform Name - March"
            }
          ]
        }]
      },
      {
        "id": "17",
        "title": "Q2 2020",
        "platforms": []
      },
      {
        "id": "20",
        "title": "Q3 2020",
        "platforms": []
      },
      {
        "id": "23",
        "title": "Q4 2020",
        "platforms": []
      }
    ]
  }
}

[samput]

Thanks @andris-sevcenko for looking in to this. Yeah it's not a deal breaker, my plan was to separate them on the front-end by type, would be nice to have the aliases, but it's not the end of the world.

[andris-sevcenko]

@samput FWIW I see the benefit in offloading such operation to the query itself so you don't have to deal with that in the front-end logic, so I'm keeping this issue open until we come to a decision about it.

[andris-sevcenko]

@samput we're planning on adding aliasing support for element queries in 3.5, which will resolve this in a more elegant manner.

[andris-sevcenko]

Alright, just added this for Craft 3.5!