problem with 'WebRequest' - no one of the overloads can be applied to the function call

New comment
 

Hi,

I have tried everything but i keep getting this error:


'WebRequest' - no one of the overloads can be applied to the function call

 bool IsHighImpactNewsUpcoming()
{
    uchar result[4096];  // Buffer for the response
    string headers[];    // Empty array for GET request
    int timeout = 30000; // Timeout in milliseconds
    string response_headers;

    int res = WebRequest("GET", NewsXML_URL, headers, timeout, NULL, 0, result, response_headers);

    if (res == -1)
    {
        Print("Error fetching news XML: ", GetLastError());
        return false;
    }

    // Convert the uchar array to a string for processing
    string response = CharArrayToString(result, 0, ArraySize(result));

    int pos = StringFind(response, "<event");
    while (pos != -1)
    {
        string event = StringSubstr(response, pos, StringFind(response, "</event>", pos) - pos + 8);
        if (StringFind(event, "<currency>USD</currency>") != -1 && StringFind(event, "<impact>High</impact>") != -1)
        {
            return true; // High-impact USD news found
        }
        pos = StringFind(response, "<event", pos + 1);
    }

    return false; // No high-impact USD news found
}

Please help..


Thanks

 

Your code:

int res = WebRequest("GET", NewsXML_URL, headers, timeout, NULL, 0, result, response_headers);


The WebRequest function has two versions, but neither uses eight parameters.



WebRequest

The function sends an HTTP request to a specified server. The function has two versions:

1. Sending simple requests of type "key=value" using the header Content-Type: application/x-www-form-urlencoded.

int  WebRequest(
   const string      method,           // HTTP method 
   const string      url,              // URL
   const string      cookie,           // cookie
   const string      referer,          // referer
   int               timeout,          // timeout
   const char        &data[],          // the array of the HTTP message body
   int               data_size,        // data[] array size in bytes
   char              &result[],        // an array containing server response data
   string            &result_headers   // headers of server response
   );

2. Sending a request of any type specifying the custom set of headers for a more flexible interaction with various Web services.

int  WebRequest(
   const string      method,           // HTTP method
   const string      url,              // URL
   const string      headers,          // headers 
   int               timeout,          // timeout
   const char        &data[],          // the array of the HTTP message body
   char              &result[],        // an array containing server response data
   string            &result_headers   // headers of server response
   );
 
Vinicius Pereira De Oliveira #:

Your code:


The WebRequest function has two versions, but neither uses eight parameters.



WebRequest

The function sends an HTTP request to a specified server. The function has two versions:

1. Sending simple requests of type "key=value" using the header Content-Type: application/x-www-form-urlencoded.


2. Sending a request of any type specifying the custom set of headers for a more flexible interaction with various Web services.

Thanks, but even after changing to 7 parameters, still not working:

bool IsHighImpactNewsUpcoming()
{
    uchar result[4096]; // Fixed-size buffer for the response
    int timeout = 30000; // Timeout in milliseconds
    string response_headers = ""; // To store response headers

    // WebRequest function call with 7 parameters
    int res = WebRequest("GET", NewsXML_URL, NULL, timeout, NULL, 0, result);

    if (res == -1)
    {
        Print("Error fetching news XML: ", GetLastError());
        return false;
    }

    if (res != 200)
    {
        Print("HTTP request failed, status code: ", res);
        return false;
    }

    // Convert response to string for processing
    string response = CharArrayToString(result, 0, ArraySize(result) - 1);

    // Process the response to check for high-impact news
    int pos = StringFind(response, "<event");
    while (pos != -1)
    {
        string event = StringSubstr(response, pos, StringFind(response, "</event>", pos) - pos + 8);
        if (StringFind(event, "<currency>USD</currency>") != -1 && StringFind(event, "<impact>High</impact>") != -1)
        {
            Print("High-impact USD news found.");
            return true;
        }
        pos = StringFind(response, "<event", pos + 1);
    }

    Print("No high-impact USD news found.");
    return false;
}
 

If you are still referring to the same error reported at the beginning of the topic, I ask that you take a closer look at the documentation... If you intend to use the version of the function with 7 parameters, you should inform something like this:

int res = WebRequest("GET", NewsXML_URL, headers, timeout, data, result, response_headers);


Data of type char, not uchar:

int  WebRequest(
   const string      method,           // HTTP method
   const string      url,              // URL
   const string      headers,          // headers 
   int               timeout,          // timeout
   const char        &data[],          // the array of the HTTP message body
   char              &result[],        // an array containing server response data
   string            &result_headers   // headers of server response
   );


See if the following article can help you with your project:

Articles

Using JSON Data API in your MQL projects

Sara Sabaghi, 2024.07.11 15:40

Imagine that you can use data that is not found in MetaTrader, you only get data from indicators by price analysis and technical analysis. Now imagine that you can access data that will take your trading power steps higher. You can multiply the power of the MetaTrader software if you mix the output of other software, macro analysis methods, and ultra-advanced tools through the ​​API data. In this article, we will teach you how to use APIs and introduce useful and valuable API data services.

New comment