From 694c590eb6dc419c848c19cdd04f09b3442b51d0 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Fri, 5 Sep 2025 18:02:12 -0500
Subject: [PATCH] [captive_portal] ESP8266: Move strings to PROGMEM (saves 192
 bytes RAM) (#10600)

---
 .../captive_portal/captive_portal.cpp         | 47 ++++++++++++++-----
 .../captive_portal/captive_portal.h           |  6 +--
 2 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/esphome/components/captive_portal/captive_portal.cpp b/esphome/components/captive_portal/captive_portal.cpp
index 25179fdacc..7eb0ffa99e 100644
--- a/esphome/components/captive_portal/captive_portal.cpp
+++ b/esphome/components/captive_portal/captive_portal.cpp
@@ -11,17 +11,35 @@ namespace captive_portal {
 static const char *const TAG = "captive_portal";
 
 void CaptivePortal::handle_config(AsyncWebServerRequest *request) {
-  AsyncResponseStream *stream = request->beginResponseStream("application/json");
-  stream->addHeader("cache-control", "public, max-age=0, must-revalidate");
+  AsyncResponseStream *stream = request->beginResponseStream(F("application/json"));
+  stream->addHeader(F("cache-control"), F("public, max-age=0, must-revalidate"));
+#ifdef USE_ESP8266
+  stream->print(F("{\"mac\":\""));
+  stream->print(get_mac_address_pretty().c_str());
+  stream->print(F("\",\"name\":\""));
+  stream->print(App.get_name().c_str());
+  stream->print(F("\",\"aps\":[{}"));
+#else
   stream->printf(R"({"mac":"%s","name":"%s","aps":[{})", get_mac_address_pretty().c_str(), App.get_name().c_str());
+#endif
 
   for (auto &scan : wifi::global_wifi_component->get_scan_result()) {
     if (scan.get_is_hidden())
       continue;
 
-    // Assumes no " in ssid, possible unicode isses?
+      // Assumes no " in ssid, possible unicode isses?
+#ifdef USE_ESP8266
+    stream->print(F(",{\"ssid\":\""));
+    stream->print(scan.get_ssid().c_str());
+    stream->print(F("\",\"rssi\":"));
+    stream->print(scan.get_rssi());
+    stream->print(F(",\"lock\":"));
+    stream->print(scan.get_with_auth());
+    stream->print(F("}"));
+#else
     stream->printf(R"(,{"ssid":"%s","rssi":%d,"lock":%d})", scan.get_ssid().c_str(), scan.get_rssi(),
                    scan.get_with_auth());
+#endif
   }
   stream->print(F("]}"));
   request->send(stream);
@@ -34,7 +52,7 @@ void CaptivePortal::handle_wifisave(AsyncWebServerRequest *request) {
   ESP_LOGI(TAG, "  Password=" LOG_SECRET("'%s'"), psk.c_str());
   wifi::global_wifi_component->save_wifi_sta(ssid, psk);
   wifi::global_wifi_component->start_scanning();
-  request->redirect("/?save");
+  request->redirect(F("/?save"));
 }
 
 void CaptivePortal::setup() {
@@ -53,18 +71,23 @@ void CaptivePortal::start() {
   this->dns_server_ = make_unique<DNSServer>();
   this->dns_server_->setErrorReplyCode(DNSReplyCode::NoError);
   network::IPAddress ip = wifi::global_wifi_component->wifi_soft_ap_ip();
-  this->dns_server_->start(53, "*", ip);
+  this->dns_server_->start(53, F("*"), ip);
   // Re-enable loop() when DNS server is started
   this->enable_loop();
 #endif
 
   this->base_->get_server()->onNotFound([this](AsyncWebServerRequest *req) {
     if (!this->active_ || req->host().c_str() == wifi::global_wifi_component->wifi_soft_ap_ip().str()) {
-      req->send(404, "text/html", "File not found");
+      req->send(404, F("text/html"), F("File not found"));
       return;
     }
 
+#ifdef USE_ESP8266
+    String url = F("http://");
+    url += wifi::global_wifi_component->wifi_soft_ap_ip().str().c_str();
+#else
     auto url = "http://" + wifi::global_wifi_component->wifi_soft_ap_ip().str();
+#endif
     req->redirect(url.c_str());
   });
 
@@ -73,19 +96,19 @@ void CaptivePortal::start() {
 }
 
 void CaptivePortal::handleRequest(AsyncWebServerRequest *req) {
-  if (req->url() == "/") {
+  if (req->url() == F("/")) {
 #ifndef USE_ESP8266
-    auto *response = req->beginResponse(200, "text/html", INDEX_GZ, sizeof(INDEX_GZ));
+    auto *response = req->beginResponse(200, F("text/html"), INDEX_GZ, sizeof(INDEX_GZ));
 #else
-    auto *response = req->beginResponse_P(200, "text/html", INDEX_GZ, sizeof(INDEX_GZ));
+    auto *response = req->beginResponse_P(200, F("text/html"), INDEX_GZ, sizeof(INDEX_GZ));
 #endif
-    response->addHeader("Content-Encoding", "gzip");
+    response->addHeader(F("Content-Encoding"), F("gzip"));
     req->send(response);
     return;
-  } else if (req->url() == "/config.json") {
+  } else if (req->url() == F("/config.json")) {
     this->handle_config(req);
     return;
-  } else if (req->url() == "/wifisave") {
+  } else if (req->url() == F("/wifisave")) {
     this->handle_wifisave(req);
     return;
   }
diff --git a/esphome/components/captive_portal/captive_portal.h b/esphome/components/captive_portal/captive_portal.h
index c78fff824a..382afe92f0 100644
--- a/esphome/components/captive_portal/captive_portal.h
+++ b/esphome/components/captive_portal/captive_portal.h
@@ -45,11 +45,11 @@ class CaptivePortal : public AsyncWebHandler, public Component {
       return false;
 
     if (request->method() == HTTP_GET) {
-      if (request->url() == "/")
+      if (request->url() == F("/"))
         return true;
-      if (request->url() == "/config.json")
+      if (request->url() == F("/config.json"))
         return true;
-      if (request->url() == "/wifisave")
+      if (request->url() == F("/wifisave"))
         return true;
     }