ui_button_handler.cpp

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#include "sensesp.h"
 
#include "ui_button_handler.h"
 
#include "sensesp/net/web/base_command_handler.h"
#include "sensesp/ui/ui_button.h"
 
namespace sensesp {
 
namespace {
 
constexpr char kButtonsUriPrefix[] = "/api/buttons/";
 
// Percent-encoding expands a character to up to three bytes, so the
// encoded tail is bounded at three times the name limit before decoding.
constexpr size_t kMaxEncodedNameLength = 3 * UIButton::kMaxNameLength;
 
void add_button_list_handler(std::shared_ptr<HTTPServer>& server) {
  auto handler = std::make_shared<HTTPRequestHandler>(
      1 << HTTP_GET, "/api/buttons", [](httpd_req_t* req) {
        JsonDocument json_doc;
        JsonArray arr = json_doc.to<JsonArray>();
 
        for (const auto& entry : UIButton::get_ui_buttons()) {
          // The click endpoint cannot resolve longer names; listing them
          // would render buttons that never work.
          if (entry.second->get_name().length() > UIButton::kMaxNameLength) {
            continue;
          }
          JsonObject obj = arr.add<JsonObject>();
          obj["name"] = entry.second->get_name();
          obj["title"] = entry.second->get_title();
          obj["mustConfirm"] = entry.second->get_must_confirm();
        }
 
        String response;
        serializeJson(json_doc, response);
        httpd_resp_set_type(req, "application/json");
        httpd_resp_sendstr(req, response.c_str());
        return ESP_OK;
      });
  server->add_handler(handler);
}
 
void add_button_click_handler(std::shared_ptr<HTTPServer>& server) {
  auto handler = std::make_shared<HTTPRequestHandler>(
      1 << HTTP_POST, String(kButtonsUriPrefix) + "*", [](httpd_req_t* req) {
        if (!check_origin(req)) {
          return ESP_FAIL;
        }
 
        String url_tail = String(req->uri).substring(strlen(kButtonsUriPrefix));
        int query_start = url_tail.indexOf('?');
        if (query_start != -1) {
          url_tail = url_tail.substring(0, query_start);
        }
        if (url_tail.length() > kMaxEncodedNameLength) {
          httpd_resp_send_err(req, HTTPD_404_NOT_FOUND,
                              "No button found with that name");
          return ESP_FAIL;
        }
        char name_cstr[kMaxEncodedNameLength + 1];
        urldecode2(name_cstr, url_tail.c_str());
        String name(name_cstr);
        if (name.length() > UIButton::kMaxNameLength) {
          httpd_resp_send_err(req, HTTPD_404_NOT_FOUND,
                              "No button found with that name");
          return ESP_FAIL;
        }
 
        const auto& buttons = UIButton::get_ui_buttons();
        auto it = buttons.find(name);
        if (it == buttons.end()) {
          httpd_resp_send_err(req, HTTPD_404_NOT_FOUND,
                              "No button found with that name");
          return ESP_FAIL;
        }
 
        httpd_resp_set_type(req, "application/json");
        httpd_resp_sendstr(req, "{\"status\":\"ok\"}");
 
        // User callbacks belong on the event loop task: the httpd task stack
        // is not sized for them, and they may touch event-loop-owned state.
        // The shared_ptr copy keeps the button alive even if a callback
        // mutates the registry. A 200 means the click was accepted, as with
        // /api/device/reset and /api/device/restart.
        auto button = it->second;
        event_loop()->onDelay(0, [button]() { button->notify(); });
        return ESP_OK;
      });
  server->add_handler(handler);
}
 
}  // namespace
 
void add_button_handlers(std::shared_ptr<HTTPServer>& server) {
  add_button_list_handler(server);
  add_button_click_handler(server);
}
 
}  // namespace sensesp