Lesson 4: Duplicating multiple blog posts at once

We can extend the previous tutorial lesson, to duplicate multiple posts with a single GraphQL request.

GraphQL query to duplicate multiple posts at once

For this GraphQL query to work, the Schema Configuration applied to the endpoint needs to have Nested Mutations enabled

This GraphQL query duplicates the posts retrieved via the provided $limit and $offset variables:

query InitializeDynamicVariables
  @configureWarningsOnExportingDuplicateVariable(enabled: false)
{
  postInputs: _echo(value: [])
    @export(as: "postInputs")
    @remove
}
 
query GetPostsAndExportData($limit: Int! = 5, $offset: Int! = 0)
  @depends(on: "InitializeDynamicVariables")
{
  postsToDuplicate: posts(
    pagination: {
      limit : $limit
      offset: $offset
    }
    sort: {
      by: ID,
      order: ASC
    }
  ) {
    # Fields not to be duplicated
    id
    slug
    date
    status
 
    # Fields to be duplicated
    author {
      id
    }
    categories {
      id
    }
    rawContent
    excerpt
    featuredImage {
      id
    }
    tags {
      id
    }
    title
 
    # Already create (and export) the inputs for the mutation
    postInputs: _echo(value: {
      status: draft,
      authorBy: {
        id: $__author
      },
      categoriesBy: {
        ids: $__categories
      },
      contentAs: {
        html: $__rawContent
      },
      excerpt: $__excerpt
      featuredImageBy: {
        id: $__featuredImage
      },
      tagsBy: {
        ids: $__tags
      },
      title: $__title
    })
      @export(as: "postInputs", type: LIST)
      @remove
  }
}
 
mutation DuplicatePosts
  @depends(on: "GetPostsAndExportData")
{
  createPosts(inputs: $postInputs) {
    status
    errors {
      __typename
      ...on ErrorPayload {
        message
      }
    }
    post {
      # Fields not to be duplicated
      id
      slug
      date
      status
 
      # Fields to be duplicated
      author {
        id
      }
      categories {
        id
      }
      rawContent
      excerpt
      featuredImage {
        id
      }
      tags {
        id
      }
      title
    }
  }
}

Step by step: creating the GraphQL query

Below is the detailed analysis of how the query works.

Extending the "Duplicating a blog post" tutorial lesson

The previous lesson employs the following strategy (on the GraphQL query of the second approach):

Export the resource IDs from the fields (including connection fields):

query GetPostAndExportData {
  post {
    author @export(as: "authorID") {
      id
    }
    categories @export(as: "categoryIDs") {
      id
    }
    rawContent @export(as: "rawContent")
    rawExcerpt @export(as: "excerpt")
    featuredImage @export(as: "featuredImageID") {
      id 
    }
    tags @export(as: "tagIDs") {
      id
    }
    rawTitle @export(as: "title")    
  }
}

Create the input object for createPost(input:) from those dynamic variables:

mutation DuplicatePost
  @depends(on: "GetPostAndExportData")
{
  createPost(input: {
    status: draft,
    authorBy: {
      id: $authorID
    },
    categoriesBy: {
      ids: $categoryIDs
    },
    contentAs: {
      html: $rawContent
    },
    excerpt: $excerpt
    featuredImageBy: {
      id: $featuredImageID
    },
    tagsBy: {
      ids: $tagIDs
    },
    title: $title
  }) {
    # ...
  }
}

Thanks to the Field to Input extension, we can create the input object already on the first operation, and export all the required post data under a single dynamic variable:

query GetPostAndExportData {
  post {
    author {
      id
    }
    categories {
      id
    }
    rawContent
    excerpt
    featuredImage {
      id
    }
    tags {
      id
    }
    title
 
    postInputs: _echo(value: {
      status: draft,
      authorBy: {
        id: $__author
      },
      categoriesBy: {
        ids: $__categories
      },
      contentAs: {
        html: $__rawContent
      },
      excerpt: $__excerpt
      featuredImageBy: {
        id: $__featuredImage
      },
      tagsBy: {
        ids: $__tags
      },
      title: $__title
    })
      @export(as: "postInputs")
  }
}

Then, in the following mutation, createPost(input:) directly receives dynamic variable $postInputs:

mutation DuplicatePost
  @depends(on: "GetPostAndExportData")
{
  createPost(input: $postInputs) {
    # ...
  }
}

Retrieving multiple posts

We must convert the query to retrieve the multiple posts to be duplicated:

Query the posts via posts(pagination: { limit : $limit, offset: $offset}) { ... }
Export postInputs as a list (i.e. an array containing all the inputs for the queried posts)

query GetPostsAndExportData($limit: Int! = 5, $offset: Int! = 0)
  @depends(on: "InitializeDynamicVariables")
{
  postsToDuplicate: posts(
    pagination: {
      limit : $limit
      offset: $offset
    }
    sort: {
      by: ID,
      order: ASC
    }
  ) {
    # ...
 
    postInputs: _echo(value: {
      # ...
    })
      @export(
        as: "postInputs",
        type: LIST
      )
  }
}

Creating multiple posts in a single GraphQL query

Dynamic variable $postInputs by now contains an array with all the input data for each of the posts to duplicate:

[
  {
    "status": "draft",
    "authorBy": {
      "id": "2"
    },
    "categoryIDs": [
      1
    ],
    "contentAs": {
      "html": "<!-- wp:paragraph -->\n<p>Welcome to WordPress. This is your first post. Edit or delete it, then start writing!</p>\n<!-- /wp:paragraph -->"
    },
    "excerpt": "Welcome to WordPress. This is your first post. Edit or delete it, then start writing!",
    "featuredImageBy": {
      "id": null
    },
    "tagsBy": {
      "ids": []
    },
    "title": "Hello world!"
  },
  {
    "status": "draft",
    "authorBy": {
      "id": "3"
    },
    "categoryIDs": [
      3
    ],
    "contentAs": {
      "html": "<!-- wp:paragraph -->\n<p>This is a paragraph block. Professionally productize highly efficient results with world-class core competencies. Objectively matrix leveraged architectures vis-a-vis error-free applications. Completely maximize customized portals via fully researched metrics. Enthusiastically generate premier action items through web-enabled e-markets. Efficiently parallel task holistic intellectual capital and client-centric markets.<br><br></p>\n<!-- /wp:paragraph -->\n\n<!-- wp:heading -->\n<h2>Image Block (Standard)</h2>\n<!-- /wp:heading -->\n\n<!-- wp:image {\"id\":1755} -->\n<figure class=\"wp-block-image\"><img src=\"https://d.pr/i/8pTmgY+\" alt=\"\" class=\"wp-image-1755\"/></figure>\n<!-- /wp:image -->"
    },
    "excerpt": "This is a paragraph block. Professionally productize highly efficient results with world-class core competencies. Objectively matrix leveraged architectures vis-a-vis error-free applications. Completely maximize customized portals via fully researched metrics. Enthusiastically generate premier action items through web-enabled e-markets. Efficiently parallel task holistic intellectual capital and client-centric markets. Image Block (Standard)",
    "featuredImageBy": {
      "id": 361
    },
    "tagsBy": {
      "ids": [
        11,
        10
      ]
    },
    "title": "Released v0.6, check it out"
  }
]

Finally, we call bulk mutation createPosts to create all the posts passing the data for the exported inputs:

mutation DuplicatePosts
  @depends(on: "GetPostsAndExportData")
{
  createPosts(inputs: $postInputs) {
    status
    errors {
      __typename
      ...on ErrorPayload {
        message
      }
    }
    post {
      # Fields not to be duplicated
      id
      slug
      date
      status
 
      # Fields to be duplicated
      author {
        id
      }
      categories {
        id
      }
      rawContent
      excerpt
      featuredImage {
        id
      }
      tags {
        id
      }
      title
    }
  }
}

Finally, we call bulk mutation createPosts to create all the posts passing all the inputs:

mutation DuplicatePosts
  @depends(on: "GetPostsAndExportData")
{
  createPosts(inputs: $postInputs) {
    status
    errors {
      __typename
      ...on ErrorPayload {
        message
      }
    }
    post {
      # Fields not to be duplicated
      id
      slug
      date
      status
 
      # Fields to be duplicated
      author {
        id
      }
      categories {
        id
      }
      rawContent
      excerpt
      featuredImage {
        id
      }
      tags {
        id
      }
      title
    }
  }
}

Removing unneeded data

The final step is to remove all fields that are auxiliary (and as such we don't need to print their output in the response) via @remove.

The consolidated GraphQL query is:

query InitializeDynamicVariables
  @configureWarningsOnExportingDuplicateVariable(enabled: false)
{
  postInputs: _echo(value: [])
    @export(as: "postInputs")
    @remove
}
 
query GetPostsAndExportData($limit: Int! = 5, $offset: Int! = 0)
  @depends(on: "InitializeDynamicVariables")
{
  postsToDuplicate: posts(
    pagination: {
      limit : $limit
      offset: $offset
    }
    sort: {
      by: ID,
      order: ASC
    }
  ) {
    # Fields not to be duplicated
    id
    slug
    date
    status
 
    # Fields to be duplicated
    author {
      id
    }
    categories {
      id
    }
    rawContent
    excerpt
    featuredImage {
      id
    }
    tags {
      id
    }
    title
 
    # Already create (and export) the inputs for the mutation
    postInputs: _echo(value: {
      status: draft,
      authorBy: {
        id: $__author
      },
      categoriesBy: {
        ids: $__categories
      },
      contentAs: {
        html: $__rawContent
      },
      excerpt: $__excerpt
      featuredImageBy: {
        id: $__featuredImage
      },
      tagsBy: {
        ids: $__tags
      },
      title: $__title
    })
      @export(as: "postInputs", type: LIST)
      @remove
  }
}
 
mutation DuplicatePosts
  @depends(on: "GetPostsAndExportData")
{
  createPosts(inputs: $postInputs) {
    status
    errors {
      __typename
      ...on ErrorPayload {
        message
      }
    }
    post {
      # Fields not to be duplicated
      id
      slug
      date
      status
 
      # Fields to be duplicated
      author {
        id
      }
      categories {
        id
      }
      rawContent
      excerpt
      featuredImage {
        id
      }
      tags {
        id
      }
      title
    }
  }
}

​GraphQL query to duplicate multiple posts at once

​Step by step: creating the GraphQL query

​Extending the "Duplicating a blog post" tutorial lesson

​Retrieving multiple posts

​Creating multiple posts in a single GraphQL query