I can't get this module to work

[sunnysideup]

This module seems to be fundamentally broken.

You can replicate it like this:

1. go to https://demo.silverstripe.org/admin/pages/

2. add the following to the about page HTMLField using the source code editor:

<div class="leftAlone ss-htmleditorfield-file embed" data-url="https://vimeo.com/event/15595" data-shortcode="embed">
    <img class="placeholder" src="pic.ng" width="1280" height="720" />
</div>

3. the page now throws a 500 error:
   https://user-images.githubusercontent.com/167154/67129986-93143980-f25c-11e9-8240-ec5bba6e7411.png

https://user-images.githubusercontent.com/167154/67130278-49781e80-f25d-11e9-9a85-bce96d0b72d4.png

As you can see the Error does not look anything like it is supposed to.

I have found the same issue on my own sites. When I save the Error Page, it does not write to the assets folder.

[tractorcow]

I've noticed the error page static file issue; The reason is that it only writes to the static file on publish, and only if it doesn't exist yet (i.e. it won't overwrite an outdated static file).

In a ChangeSet, if a page has no changes, ErrorPage::publishSingle() is never called, and no static page is written. This means saving an unchanged page in the CMS doesn't publish this file.

    /**
     * When an error page is published, create a static HTML page with its
     * content, so the page can be shown even when SilverStripe is not
     * functioning correctly before publishing this page normally.
     *
     * @return bool True if published
     */
    public function publishSingle()
    {
        if (!parent::publishSingle()) {
            return false;
        }
        return $this->writeStaticPage();
    }

A second issue is during dev/build, the static page is only written if missing (never updated).

// Ensure this page has cached error content
        $success = true;
        if (!$page->hasStaticPage()) {
            // Update static content
            $success = $page->writeStaticPage();
        } elseif ($pageExists) {
            // If page exists and already has content, no alteration_message is displayed
            return;
        }

My fix is to override requireDefaultRecords() and implement a custom static builder.

/**
     * @throws ValidationException
     */
    public function requireDefaultRecords()
    {
        parent::requireDefaultRecords();
        $this->buildErrorPage();
    }

full gist https://gist.github.com/tractorcow/2145af6cdedd6f8d3c9a8f5f46e2bf7d

[sunnysideup]

Thank you.

Can we fix this properly in the module? I am happy to make a pull request.

[michalkleiner]

@sunnysideup still keen to provide a PR?