add support for Ads Assistant header via middleware

src/Google/Ads/GoogleAds/Lib/V20/AdsAssistantHeaderMiddleware.php

@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Google\Ads\GoogleAds\Lib\V20;
+
+use Google\ApiCore\Call;
+use Google\ApiCore\AgentHeader;
+use Google\ApiCore\Middleware\MiddlewareInterface;
+
+/**
+ * Appends ads assistant metadata to the x-goog-api-client header.
+ */
+class AdsAssistantHeaderMiddleware implements MiddlewareInterface
+{
+    private $nextHandler;
+    private $adsAssistant;
+
+    public function __construct(callable $nextHandler, string $adsAssistant)
+    {
+        $this->nextHandler = $nextHandler;
+        $this->adsAssistant = $adsAssistant;
+    }
+
+    public function __invoke(Call $call, array $options)
+    {
+        // Check if the agent header exists to avoid errors
+        if (isset($options['headers'][AgentHeader::AGENT_HEADER_KEY][0])) {
+            $options['headers'][AgentHeader::AGENT_HEADER_KEY][0] .= sprintf(
+                ' gaada/%s',
+                $this->adsAssistant
+            );
+        }
+
+        $next = $this->nextHandler;
+        return $next($call, $options);
+    }
+}

src/Google/Ads/GoogleAds/Lib/V20/GoogleAdsGapicClientTrait.php

@@ -38,7 +38,7 @@ trait GoogleAdsGapicClientTrait
     private static $UNARY_MIDDLEWARES = 'unary-middlewares';
     private static $STREAMING_MIDDLEWARES = 'streaming-middlewares';
     private static $ADS_ASSISTANT_HEADER_NAME = 'google-ads-api-assistant';
-
+    
     private $developerToken = null;
     private $loginCustomerId = null;
     private $linkedCustomerId = null;
@@ -79,9 +79,6 @@ protected function modifyClientOptions(array &$options)
 
     /**
      * Adds a FixedHeaderMiddleware to a callable.
-     *
-     * @param callable $callable the callable to add to
-     * @return callable the modified callable
      */
     private function addFixedHeaderMiddleware(callable &$callable)
     {
@@ -115,6 +112,11 @@ protected function modifyUnaryCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $unaryMiddleware */
             $callable = $unaryMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     /**
@@ -129,6 +131,11 @@ protected function modifyStreamingCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $streamingMiddleware */
             $callable = $streamingMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     public function getResponseMetadata(): ?GoogleAdsResponseMetadata

src/Google/Ads/GoogleAds/Lib/V21/AdsAssistantHeaderMiddleware.php

@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Google\Ads\GoogleAds\Lib\V21;
+
+use Google\ApiCore\Call;
+use Google\ApiCore\AgentHeader;
+use Google\ApiCore\Middleware\MiddlewareInterface;
+
+/**
+ * Appends ads assistant metadata to the x-goog-api-client header.
+ */
+class AdsAssistantHeaderMiddleware implements MiddlewareInterface
+{
+    private $nextHandler;
+    private $adsAssistant;
+
+    public function __construct(callable $nextHandler, string $adsAssistant)
+    {
+        $this->nextHandler = $nextHandler;
+        $this->adsAssistant = $adsAssistant;
+    }
+
+    public function __invoke(Call $call, array $options)
+    {
+        // Check if the agent header exists to avoid errors
+        if (isset($options['headers'][AgentHeader::AGENT_HEADER_KEY][0])) {
+            $options['headers'][AgentHeader::AGENT_HEADER_KEY][0] .= sprintf(
+                ' gaada/%s',
+                $this->adsAssistant
+            );
+        }
+
+        $next = $this->nextHandler;
+        return $next($call, $options);
+    }
+}

src/Google/Ads/GoogleAds/Lib/V21/GoogleAdsGapicClientTrait.php

@@ -79,9 +79,6 @@ protected function modifyClientOptions(array &$options)
 
     /**
      * Adds a FixedHeaderMiddleware to a callable.
-     *
-     * @param callable $callable the callable to add to
-     * @return callable the modified callable
      */
     private function addFixedHeaderMiddleware(callable &$callable)
     {
@@ -115,6 +112,11 @@ protected function modifyUnaryCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $unaryMiddleware */
             $callable = $unaryMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     /**
@@ -129,6 +131,11 @@ protected function modifyStreamingCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $streamingMiddleware */
             $callable = $streamingMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     public function getResponseMetadata(): ?GoogleAdsResponseMetadata

src/Google/Ads/GoogleAds/Lib/V22/AdsAssistantHeaderMiddleware.php

@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Google\Ads\GoogleAds\Lib\V22;
+
+use Google\ApiCore\Call;
+use Google\ApiCore\AgentHeader;
+use Google\ApiCore\Middleware\MiddlewareInterface;
+
+/**
+ * Appends ads assistant metadata to the x-goog-api-client header.
+ */
+class AdsAssistantHeaderMiddleware implements MiddlewareInterface
+{
+    private $nextHandler;
+    private $adsAssistant;
+
+    public function __construct(callable $nextHandler, string $adsAssistant)
+    {
+        $this->nextHandler = $nextHandler;
+        $this->adsAssistant = $adsAssistant;
+    }
+
+    public function __invoke(Call $call, array $options)
+    {
+        // Check if the agent header exists to avoid errors
+        if (isset($options['headers'][AgentHeader::AGENT_HEADER_KEY][0])) {
+            $options['headers'][AgentHeader::AGENT_HEADER_KEY][0] .= sprintf(
+                ' gaada/%s',
+                $this->adsAssistant
+            );
+        }
+
+        $next = $this->nextHandler;
+        return $next($call, $options);
+    }
+}

src/Google/Ads/GoogleAds/Lib/V22/GoogleAdsGapicClientTrait.php

@@ -82,9 +82,6 @@ protected function modifyClientOptions(array &$options)
 
     /**
      * Adds a FixedHeaderMiddleware to a callable.
-     *
-     * @param callable $callable the callable to add to
-     * @return callable the modified callable
      */
     private function addFixedHeaderMiddleware(callable &$callable)
     {
@@ -121,6 +118,11 @@ protected function modifyUnaryCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $unaryMiddleware */
             $callable = $unaryMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     /**
@@ -135,6 +137,11 @@ protected function modifyStreamingCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $streamingMiddleware */
             $callable = $streamingMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     public function getResponseMetadata(): ?GoogleAdsResponseMetadata

src/Google/Ads/GoogleAds/Lib/V23/AdsAssistantHeaderMiddleware.php

@@ -0,0 +1,52 @@
+<?php
+
+/*
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace Google\Ads\GoogleAds\Lib\V23;
+
+use Google\ApiCore\Call;
+use Google\ApiCore\AgentHeader;
+use Google\ApiCore\Middleware\MiddlewareInterface;
+
+/**
+ * Appends ads assistant metadata to the x-goog-api-client header.
+ */
+class AdsAssistantHeaderMiddleware implements MiddlewareInterface
+{
+    private $nextHandler;
+    private $adsAssistant;
+
+    public function __construct(callable $nextHandler, string $adsAssistant)
+    {
+        $this->nextHandler = $nextHandler;
+        $this->adsAssistant = $adsAssistant;
+    }
+
+    public function __invoke(Call $call, array $options)
+    {
+        // Check if the agent header exists to avoid errors
+        if (isset($options['headers'][AgentHeader::AGENT_HEADER_KEY][0])) {
+            $options['headers'][AgentHeader::AGENT_HEADER_KEY][0] .= sprintf(
+                ' gaada/%s',
+                $this->adsAssistant
+            );
+        }
+
+        $next = $this->nextHandler;
+        return $next($call, $options);
+    }
+}

src/Google/Ads/GoogleAds/Lib/V23/GoogleAdsGapicClientTrait.php

@@ -82,9 +82,6 @@ protected function modifyClientOptions(array &$options)
 
     /**
      * Adds a FixedHeaderMiddleware to a callable.
-     *
-     * @param callable $callable the callable to add to
-     * @return callable the modified callable
      */
     private function addFixedHeaderMiddleware(callable &$callable)
     {
@@ -103,6 +100,7 @@ private function addFixedHeaderMiddleware(callable &$callable)
             if (!is_null($this->adsAssistant)) {
                 $headers[self::$ADS_ASSISTANT_HEADER_NAME] = [$this->adsAssistant];
             }
+
             $callable = new FixedHeaderMiddleware($callable, $headers);
         }
         return $callable;
@@ -120,6 +118,11 @@ protected function modifyUnaryCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $unaryMiddleware */
             $callable = $unaryMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     /**
@@ -134,6 +137,11 @@ protected function modifyStreamingCallable(callable &$callable)
             /** @var GoogleAdsMiddlewareAbstract $streamingMiddleware */
             $callable = $streamingMiddleware->withNextHandler($callable);
         }
+
+        // Prepend the AdsAssistantHeaderMiddleware
+        if (!is_null($this->adsAssistant)) {
+            $callable = new AdsAssistantHeaderMiddleware($callable, $this->adsAssistant);
+        }
     }
 
     public function getResponseMetadata(): ?GoogleAdsResponseMetadata