What causes "Document data is not provided" in octobercms/october?

Send documentData as an array containing at least key and type, e.g. documentData[key]=blog/posts.yaml&documentData[type]=tailor-blueprint.

octobercms/october · error · SystemException

Document data is not provided

Error message

Document data is not provided

What it means

command_onOpenDocument() is the AJAX handler the October editor extension client invokes when a document is opened. It requires a `documentData` array in the POST body (with at least `key` and `type`). If post('documentData') is missing or not an array, it throws SystemException('Document data is not provided') before doing any work.

Source

Thrown at modules/tailor/classes/editorextension/HasExtensionCrud.php:30

use Editor\Classes\ApiHelpers;
use Tailor\Classes\BlueprintIndexer;
use Tailor\Classes\BlueprintVerifier;
use Tailor\Classes\BlueprintException;
use Tailor\Classes\BlueprintErrorData;

/**
 * HasExtensionCrud implements CRUD operations for the Tailor Editor Extension
 */
trait HasExtensionCrud
{
    /**
     * command_onOpenDocument
     */
    protected function command_onOpenDocument()
    {
        $documentData = post('documentData');
        if (!is_array($documentData)) {
            throw new SystemException('Document data is not provided');
        }

        $key = ApiHelpers::assertGetKey($documentData, 'key');
        $documentType = ApiHelpers::assertGetKey($documentData, 'type');
        $this->assertDocumentTypePermissions($documentType);

        $extraData = $this->getRequestExtraData();

        $isResetFromTemplateFileRequest = isset($extraData['resetFromTemplateFile']);
        if ($isResetFromTemplateFileRequest) {
            $this->resetFromTemplateFile($documentType, $key);
        }

        $template = $this->loadTemplate($documentType, $key);
        $templateData = [
            'content' => $template->content,
            'fileName' => ltrim($template->fileName, '/')
        ];

View on GitHub (pinned to b608633a7e)

Solutions

Send documentData as an array containing at least key and type, e.g. documentData[key]=blog/posts.yaml&documentData[type]=tailor-blueprint.
After upgrading October, clear browser/CDN caches so the editor client sends the current payload shape.
Confirm the request reaches the intended tailor handler and is not being redirected or stripped by middleware.

Example fix

// before (missing payload)
$.request('onEditorOpenDocument');

// after
$.request('onEditorOpenDocument', {
    data: { documentData: { key: 'blueprints/blog/posts.yaml', type: 'tailor-blueprint' } }
});

Defensive patterns

Strategy: validation

Validate before calling

// Client side: always send the expected payload shape
const payload = { documentData: { key: path, type: 'tailor-blueprint' } };
$.request('onEditorCommand', { data: { command: 'onOpenDocument', ...payload } });

Try / catch

try {
    // invoke editor extension open command
} catch (\SystemException $e) {
    // payload missing documentData — rebuild request from the document's key/type and retry once
}

Prevention

When integrating with the editor extension, replicate the exact payloads the core client sends (documentData.key, documentData.type).
Add contract tests for custom AJAX handlers asserting required payload keys.
Clear cached editor assets after CMS upgrades.

When it happens

Trigger: POSTing to the editor extension endpoint without a documentData payload; sending documentData as a raw JSON string instead of a parsed array; a custom client or automated test hitting the handler directly with an incomplete body.

Common situations: Custom integrations with the editor extension; stale editor frontend assets after a CMS upgrade sending a changed payload shape; test fixtures built for an older payload format.

Related errors

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/ab2d3925fc8e8ca2. Report an issue: GitHub.