---
title: "lzb/block_render/template_exists"
description: "PHP filter `lzb/block_render/template_exists` of the Lazy Blocks WordPress plugin."
url: "https://www.lazyblocks.com/docs/php-filters/lzb-block_render-template_exists/"
lastUpdated: 2026-09-09
source: "php-filters/lzb-block_render-template_exists.mdx"
---
# lzb/block_render/template_exists

Tells Lazy Blocks that a block template lives somewhere the theme lookup will never reach, such as inside a plugin that ships blocks of its own.

A block whose **Output Method** is **Theme Template** is rendered from `/blocks/BLOCK-SLUG/block.php` in the active theme, or `/blocks/BLOCK-SLUG/editor.php` in the editor. `template_exists()` resolves that name with `locate_template()`, fires this filter, then returns `file_exists()` on the result. So the filter decides whether the template is considered to be there at all, and its partner [lzb/block_render/include_template](https://www.lazyblocks.com/docs/php-filters/lzb-block_render-include_template/) decides which file is actually loaded. Filter one without the other and Lazy Blocks reports a template it then fails to include.

## Attributes

| Name               | Type              | Description                                                                            |
| ------------------ | ----------------- | -------------------------------------------------------------------------------------- |
| `$template`        | **String**        | path found by `locate_template()`, empty when the theme has no such file               |
| `$template_name`   | **String**        | name being looked up, for example `/blocks/lazyblock-recipe/block.php`                 |
| `$attributes`      | **Array**         | control values, as the template will see them                                          |
| `$block`           | **Array**         | block data, the same array [lzb/block_data](https://www.lazyblocks.com/docs/php-filters/lzb-block_data/) returns |
| `$render_location` | **String**        | `editor` or `frontend`                                                                 |
| `$context`         | **Array \| null** | block context from parent blocks                                                       |

## Additional Filters

| Name                                            | Arguments                                                                    | Description                         |
| ----------------------------------------------- | ---------------------------------------------------------------------------- | ----------------------------------- |
| `lazyblock/BLOCK_SLUG/frontend_template_exists` | `$template, $template_name, $attributes, $block, $context`                   | specific block in the frontend only |
| `lazyblock/BLOCK_SLUG/editor_template_exists`   | `$template, $template_name, $attributes, $block, $context`                   | specific block in the editor only   |
| `lazyblock/BLOCK_SLUG/template_exists`          | `$template, $template_name, $attributes, $block, $render_location, $context` | specific block only                 |

A shorter filter named `lzb/template_exists` is still in the code for compatibility. It takes `( $template, $template_name, $args )`, where `$args` is the whole array holding `attributes`, `block`, `render_location` and `context` rather than those four unpacked. It fires after every filter in the table above, so whatever it returns wins. New code should use the `block_render` name. See [lzb/template_exists](https://www.lazyblocks.com/docs/php-filters/lzb-template_exists/).

## Usage

```php title="PHP"
function my_lzb_block_render_template_exists( $template, $template_name, $attributes, $block, $render_location, $context ) {
  // Serve block templates from the plugin when the theme has none, so a
  // theme switch does not take the blocks down with it.
  if ( $template ) {
    return $template;
  }

  $fallback = plugin_dir_path( __FILE__ ) . ltrim( $template_name, '/' );

  return file_exists( $fallback ) ? $fallback : $template;
}

add_filter( 'lzb/block_render/template_exists', 'my_lzb_block_render_template_exists', 10, 6 );
```

Return a path, not a boolean. The name reads like a yes or no question, but Lazy Blocks calls `file_exists()` on your return value, so `true` becomes the string `1` and the check fails. Returning an empty string sends the block to `templates/template-not-found.php` inside the plugin, which prints a "Template file not found" notice where the block should have been.

Register the same fallback on [lzb/block_render/include_template](https://www.lazyblocks.com/docs/php-filters/lzb-block_render-include_template/), or the file is found and never loaded. Theme templates are covered in [Theme Template](https://www.lazyblocks.com/docs/blocks-code/theme-template/).

## Documentation Index
> Fetch the complete documentation index at: https://www.lazyblocks.com/llms.txt
> Fetch every page in a single file at: https://www.lazyblocks.com/llms-full.txt