Add callback for content src= replacement (#90)

* feat: Add callback for content src= replacement

* Match full domain path in src attr

docs/previews/README.md

@@ -19,7 +19,7 @@ Checkout the [example project](/examples/preview) to see how it works.
 
 ## WPE Headless Plugin
 
-In order to enable previews in WordPress, you'll first need to install the [wpe-headless plugin](https://github.com/wpengine/headless-framework/releases/download/v0.0.1-alpha.1/wpe-headless-plugin.zip). You also need to install [WPGraphQL](https://wordpress.org/plugins/wp-graphql/).
+In order to enable previews in WordPress, you'll first need to install the [wpe-headless plugin](https://wp-product-info.wpesvc.net/v1/plugins/wpe-headless?download). You also need to install [WPGraphQL](https://wordpress.org/plugins/wp-graphql/).
 
 The plugin enables an OAuth flow for users to authenticate with WordPress and receive an access token which is used for subsequent API calls (i.e. GQL/REST).
 

plugins/wpe-headless/includes/replacement/callbacks.php

@@ -35,6 +35,30 @@ function wpe_headless_content_replacement( $content ) {
 	return str_replace( 'href="//', 'href="/', $content );
 }
 
+add_filter( 'the_content', 'wpe_headless_content_media_replacement' );
+/**
+ * Callback for WordPress 'the_content' filter to replace paths to media.
+ *
+ * @param string $content The post content.
+ *
+ * @return string The post content.
+ * @todo Needs work...
+ */
+function wpe_headless_content_media_replacement( $content ) {
+	if ( ! wpe_headless_domain_replacement_enabled() ) {
+		return $content;
+	}
+
+	$frontend_uri = wpe_headless_get_setting( 'frontend_uri' );
+	$site_url     = site_url();
+
+	if ( ! $frontend_uri ) {
+		$frontend_uri = '/';
+	}
+
+	return str_replace( "src=\"{$frontend_uri}/", "src=\"{$site_url}/", $content );
+}
+
 add_filter( 'preview_post_link', 'wpe_headless_post_preview_link', 10, 2 );
 /**
  * Callback for WordPress 'preview_post_link' filter.

plugins/wpe-headless/tests/integration/replacement/test-replacement-callbacks.php

@@ -57,6 +57,20 @@ public function test_wpe_headless_content_replacement_filters_content_when_conte
 		remove_filter( 'wpe_headless_domain_replacement_enabled', '__return_true' );
 	}
 
+	/**
+	 * Tests wpe_headless_content_media_replacement() replaces the frontend_uri value when content replacement is enabled.
+	 */
+	public function test_wpe_headless_content_media_replacement_filters_content_when_content_replacement_enabled() {
+		wpe_headless_update_setting( 'frontend_uri', 'http://foo.co' );
+		add_filter( 'wpe_headless_domain_replacement_enabled', '__return_true' );
+		# Do not replace partial domain match.
+		$this->assertSame( '<img src="http://foo.com/image.png">', wpe_headless_content_media_replacement( '<img src="http://foo.com/image.png">' ) );
+		# Do replace exact domain match
+		$this->assertSame( '<img src="http://example.org/image.png">', wpe_headless_content_media_replacement( '<img src="http://foo.co/image.png">' ) );
+		wpe_headless_update_setting( 'frontend_uri', null );
+		remove_filter( 'wpe_headless_domain_replacement_enabled', '__return_true' );
+	}
+
 	/**
 	 * Tests get_permalink() returns the original value when content replacement is not enabled.
 	 *