---
id: gk-gravitymigrate-background-external-importer-resolver
title: "Filter - gk/gravitymigrate/background/external-importer-resolver"
sidebar_label: "gk/gravitymigrate/background/external-importer-resolver"
---

# Filter: gk/gravitymigrate/background/external-importer-resolver

Filters the callable the external-import background driver uses to resolve a provider slug to its registered importer.

The test seam for ExternalImportJobDriver: a test may substitute a scripted resolver for the real importer registry.

## Parameters

| Name | Type | Description |
|------|------|-------------|
| $resolver | `callable` | Takes a provider slug, returns <code>ImporterInterface\|null</code>. |

### Since

- %ver%: %ver%

### Source

Defined in `src/Background/ExternalImportJobDriver.php` at line 402