Getting domdocument::loadHTML(): Argument #1 ($source) must not be empty when button is empty

[Skatox]

If you do:

1. Add a regular Gutenberg button without text, like dragging it from the left panel.
2. Leave the button there and publish a new page.
3. Query the page with Faust.js and get the Button attributes.

You'll get an internal server error saying that domdocument::loadHTML(): Argument #1 ($source) must not be empty when the button is empty. If you add some text to the button, the problem will disappear.

This is a problem if you rebuild multiple pages and one of them has an information skeleton without any values. It won't work.

[justlevine]

Not sure if it's preexisting or linked via one of our PRs, but I'm pretty sure I've addressed this upstream (assumed the issue was only in the branch) at rtCamp#31

Should have time to backport a fix this week 🤞

[justlevine]

On second look, I'm unable to replicate this using the latest main (v4.3.0)

@Skatox would you be able to confirm what version of plugin you are using and provide a replicable test case?

Here's mine:

Post content:

<!-- wp:buttons -->
<div class="wp-block-buttons"><!-- wp:button -->
<div class="wp-block-button"><a class="wp-block-button__link wp-element-button"></a></div>
<!-- /wp:button --></div>
<!-- /wp:buttons -->

<!-- wp:paragraph -->
<p></p>
<!-- /wp:paragraph -->

Query:

query TestButtons($uri: String!) {
  nodeByUri(uri:$uri){
    ... on NodeWithEditorBlocks {
      editorBlocks{
        __typename
        ... on CoreButtons {
          attributes {
            align
            anchor
            backgroundColor
            borderColor
            className
            cssClassName
            fontFamily
            fontSize
            gradient
            layout
            lock
            metadata
            style
          }
        }
        ... on CoreButton {
          attributes {
            anchor
            backgroundColor
            borderColor
            className
            cssClassName
            fontFamily
            fontSize
            gradient
            placeholder
            linkClassName
            linkTarget
            lock
            metadata
            placeholder
            rel
            style
            tagName
            text
            textAlign
            textColor
            title
            type
            url
            width
          }
        }
      }
    }
  }
}

Results:

[theodesp]

Released in https://github.com/wpengine/wp-graphql-content-blocks/releases/tag/v4.3.2