online_image: allow setting templatable headers on http request

esphome/components/online_image/__init__.py

@@ -28,6 +28,7 @@ MULTI_CONF = True
 
 CONF_ON_DOWNLOAD_FINISHED = "on_download_finished"
 CONF_PLACEHOLDER = "placeholder"
+CONF_HTTP_REQUEST_HEADERS = "http_request_headers"
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -86,6 +87,9 @@ ONLINE_IMAGE_SCHEMA = cv.Schema(
                 cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(DownloadErrorTrigger),
             }
         ),
+        cv.Optional(CONF_HTTP_REQUEST_HEADERS): cv.All(
+            cv.Schema({cv.string: cv.templatable(cv.string)})
+        ),
     }
 ).extend(cv.polling_component_schema("never"))
 
@@ -154,6 +158,12 @@ async def to_code(config):
 
     cg.add(var.set_transparency(transparent))
 
+    for key in config.get(CONF_HTTP_REQUEST_HEADERS, []):
+        template_ = await cg.templatable(
+            config[CONF_HTTP_REQUEST_HEADERS][key], [], cg.optional.template(cg.const_char_ptr)
+        )
+        cg.add(var.add_header(key, template_))
+
     if placeholder_id := config.get(CONF_PLACEHOLDER):
         placeholder = await cg.get_variable(placeholder_id)
         cg.add(var.set_placeholder(placeholder))

esphome/components/online_image/online_image.cpp

@@ -103,7 +103,16 @@ void OnlineImage::update() {
     ESP_LOGI(TAG, "Updating image");
   }
 
-  this->downloader_ = this->parent_->get(this->url_);
+
+  std::list<http_request::Header> headers;
+  for (const auto &item : this->headers_) {
+    auto val = item.second();
+    if (val.has_value()) {
+      headers.push_back(http_request::Header{item.first, *val});
+    }
+  }
+
+  this->downloader_ = this->parent_->get(this->url_, headers);
 
   if (this->downloader_ == nullptr) {
     ESP_LOGE(TAG, "Download failed.");

esphome/components/online_image/online_image.h

@@ -62,6 +62,8 @@ class OnlineImage : public PollingComponent,
     }
   }
 
+  void add_header(const char *key, std::function<optional<const char*>()> &&f) { this->headers_.insert({key, f}); }
+
   /**
    * @brief Set the image that needs to be shown as long as the downloaded image
    *  is not available.
@@ -122,6 +124,7 @@ class OnlineImage : public PollingComponent,
   image::Image *placeholder_{nullptr};
 
   std::string url_{""};
+  std::map<const char *, std::function<optional<const char*>()>> headers_{};
 
   /** width requested on configuration, or 0 if non specified. */
   const int fixed_width_;