WebSockets ​

Web sockets is an advanced technology that allows you to open a permanent bi-directional network connection between the user's browser and the server. With its API, you can send a message to the server and receive a response without making an http request, and this process will be event-driven.

Requests ​

Requests made to an application are represented as a websocketsrequest_t structure that provides information about the parameters of the WebSocket request - method, type, resource, data, and so on.

Request format: [method] [path] [payload].

The method, path, and payload are separated by a single space, for example:

GET /
GET /users?id=100
POST /users {"id": 100, "name":"Alex"}
PATCH /users/100 {"name":"Alen"}
DELETE /users/100

GET request parameters ​

To get query parameters, you must call the query() method of the websocketsrequest component

void get(websocketsrequest_t* request, websocketsresponse_t* response) {
    const char* data = request->query(request, "mydata");

    if (data) {
        response->text(response, data);
        return;
    }

    response->text(response, "Data not found");
}

POST and PATCH request data ​

The data that was sent via POST and PATCH is sent in the body of the request.

They are accessed through methods:

• payload()
• payload_json()

void post(websocketsrequest_t* request, websocketsresponse_t* response) {
    char* payload = request->payload(request);

    if (!payload) {
        response->text(response, "Payload not found");
        return;
    }

    response->text(response, payload);

    free(payload);
}

Request methods ​

You can get the name of the HTTP method used in the current request by accessing the request->method property.

The following methods are available:

• ROUTE_GET
• ROUTE_POST
• ROUTE_PATCH
• ROUTE_DELETE

void get(websocketsrequest_t* request, websocketsresponse_t* response) {
    const char* data = request->method == ROUTE_GET ?
        "This is the get method" :
        "This is the not get method";

    response->text(response, data);
}

Request URL ​

The request component provides three properties for working with urls:

• uri - will return the relative address of the resource /resource.html?id=100&text=hello.
• path - will return the path to the resource without parameters /resource.html.
• ext - will return the extension from the resource name html or an empty string.

The length of each property is also calculated:

• uri_length
• path_length
• ext_length