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Schema tutorial
Schema tutorialLesson 17: Automatically adding a mandatory block

Lesson 17: Automatically adding a mandatory block

Whenever a new post is created, we can use the automation features to validate and modify the content of the post.

The query in this tutorial lesson checks if a certain mandatory block is present in the post and, whenever missing, it adds it.

GraphQL query to add a missing block

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

This GraphQL query checks if the mandatory block wp:comments has already been added to the post. If missing, it is added at the bottom of the content.

Save this content as a Persisted Query, with slug insert-mandatory-comments-block-if-missing:

query CheckIfCommentsBlockExists($postId: ID!) {
  posts(
    filter: {
      ids: [$postId]
      search: "\"<!-- /wp:comments -->\""
    }
  ) {
    id
  }
  blockExists: _notEmpty(value: $__posts)
    @export(as: "blockExists")
}
 
mutation MaybeInsertCommentsBlock($postId: ID!)
  @depends(on: "CheckIfCommentsBlockExists")
  @skip(if: $blockExists)
{
  post(by: { id: $postId }) {
    id
    rawContent
    adaptedRawContent: _strAppend(
      after: $__rawContent
      append: """
 
<!-- wp:comments -->
<div class="wp-block-comments"><!-- wp:comments-title /-->
 
<!-- wp:comment-template -->
<!-- wp:columns -->
<div class="wp-block-columns"><!-- wp:column {"width":"40px"} -->
<div class="wp-block-column" style="flex-basis:40px"><!-- wp:avatar {"size":40,"style":{"border":{"radius":"20px"}}} /--></div>
<!-- /wp:column -->
 
<!-- wp:column -->
<div class="wp-block-column"><!-- wp:comment-author-name {"fontSize":"small"} /-->
 
<!-- wp:group {"style":{"spacing":{"margin":{"top":"0px","bottom":"0px"}}},"layout":{"type":"flex"}} -->
<div class="wp-block-group" style="margin-top:0px;margin-bottom:0px"><!-- wp:comment-date {"fontSize":"small"} /-->
 
<!-- wp:comment-edit-link {"fontSize":"small"} /--></div>
<!-- /wp:group -->
 
<!-- wp:comment-content /-->
 
<!-- wp:comment-reply-link {"fontSize":"small"} /--></div>
<!-- /wp:column --></div>
<!-- /wp:columns -->
<!-- /wp:comment-template -->
 
<!-- wp:comments-pagination -->
<!-- wp:comments-pagination-previous /-->
 
<!-- wp:comments-pagination-numbers /-->
 
<!-- wp:comments-pagination-next /-->
<!-- /wp:comments-pagination -->
 
<!-- wp:post-comments-form /--></div>
<!-- /wp:comments -->   
 
      """
    )
    update(input: {
      contentAs: { html: $__adaptedRawContent },
    }) {
      status
      errors {
        __typename
        ...on ErrorPayload {
          message
        }
      }
      post {
        id
        rawContent
      }
    }
  }
}

Adding hook to execute Persisted Query

The Internal GraphQL Server by default applies the Schema Configuration defined in its own Settings.

Then, for this GraphQL query to work, the Schema Configuration applied to the Internal GraphQL Server needs to have Nested Mutations enabled.

This PHP code hooks into WordPress action draft_post to execute the Persisted Query (via the Internal GraphQL Server extension):

use GatoGraphQL\InternalGraphQLServer\GraphQLServer;
use WP_Post;
 
add_action(
  'draft_post',
  function (int $postID): void {
    GraphQLServer::executePersistedQuery(
      'insert-mandatory-comments-block-if-missing',
      [
        'postId' => $postID,
      ],
      'MaybeInsertCommentsBlock'
    );
  }
);