Lightweight HTTP client for ESP32

Example

This project is no longer supported, please use

https://github.com/espressif/esp-idf/tree/master/components/esp_http_client

int download_callback(request_t *req, char *data, int len)
{
    req_list_t *found = req->response->header;
    while(found->next != NULL) {
        found = found->next;
        ESP_LOGI(TAG,"Response header %s:%s", (char*)found->key, (char*)found->value);
    }
    //or 
    found = req_list_get_key(req->response->header, "Content-Length");
    if(found) {
        ESP_LOGI(TAG,"Get header %s:%s", (char*)found->key, (char*)found->value);
    }
    ESP_LOGI(TAG,"%s", data);
    return 0;
}
static void request_task(void *pvParameters)
{
    request_t *req;
    int status;
    xEventGroupWaitBits(wifi_event_group, CONNECTED_BIT, false, true, portMAX_DELAY);
    ESP_LOGI(TAG, "Connected to AP, freemem=%d",esp_get_free_heap_size());
    // vTaskDelay(1000/portTICK_RATE_MS);
    req = req_new("http://httpbin.org/post"); 
    //or
    //request *req = req_new("https://google.com"); //for SSL
    req_setopt(req, REQ_SET_METHOD, "POST");
    req_setopt(req, REQ_SET_POSTFIELDS, "test=data&test2=data2");
    req_setopt(req, REQ_FUNC_DOWNLOAD_CB, download_callback);
    status = req_perform(req);
    req_clean(req);
    vTaskDelete(NULL);
}

Websocket

int websocket_cb(request_t *req, int status, void *buffer, int len)
{
    switch(status) {
        case WS_CONNECTED:
            ESP_LOGI(TAG, "websocket connected");
            req_write(req, "hello world", 11);
            break;
        case WS_DATA:
            ((char*)buffer)[len] = 0;
            ESP_LOGI(TAG, "websocket data = %s", (char*)buffer);
            req_close(req);
            break;
        case WS_DISCONNECTED:
            ESP_LOGI(TAG, "websocket disconnected");
            req_clean(req);
            req = NULL;
            break;
    }
    return 0;
}
void app()
{
    request_t *req = req_new("ws://echo.websocket.org"); // or wss://echo.websocket.org
    req_setopt(req, REQ_FUNC_WEBSOCKET, websocket_cb);
    req_perform(req);
}

Usage

• Create ESP-IDF application https://github.com/espressif/esp-idf-template
• Clone git submodule add https://github.com/tuanpmt/esp-request components/esp-request
• Example esp-request application: https://github.com/tuanpmt/esp-request-app
• OTA application using esp-request: https://github.com/tuanpmt/esp32-fota

API

Function

• req_new
• req_setopt
• req_clean

Options for req_setopt

• REQ_SET_METHOD - req_setopt(req, REQ_SET_METHOD, "GET");//or POST/PUT/DELETE
• REQ_SET_HEADER - req_setopt(req, REQ_SET_HEADER, "HeaderKey: HeaderValue");
• REQ_SET_HOST - req_setopt(req, REQ_SET_HOST, "google.com"); //or 192.168.0.1
• REQ_SET_PORT - req_setopt(req, REQ_SET_PORT, "80");//must be string
• REQ_SET_PATH - req_setopt(req, REQ_SET_PATH, "/path");
• REQ_SET_SECURITY
• REQ_SET_URI - req_setopt(req, REQ_SET_URI, "http://uri.com"); //will replace host, port, path, security and Auth if present
• REQ_SET_DATAFIELDS
• REQ_SET_UPLOAD_LEN - Not effect for now
• REQ_FUNC_DOWNLOAD_CB - req_setopt(req, REQ_FUNC_DOWNLOAD_CB, download_callback);
• REQ_FUNC_UPLOAD_CB
• REQ_FUNC_WEBSOCKET
• REQ_REDIRECT_FOLLOW - req_setopt(req, REQ_REDIRECT_FOLLOW, "true"); //or "false"

URI format

• Follow this: https://en.wikipedia.org/wiki/Uniform_Resource_Identifier

Todo

• Support URI parser
• Follow redirect
• Support SSL
• Support Set POST Fields (simple)
• Support Websocket & Websocket Secure
• Support Basic Auth
• Support Upload multipart
• Support Cookie

Known Issues

• Uri parse need more work

Authors

• Tuan PM