response.GetField("Content-Length") returns 0

[Spellbreaker]

Hello!

I have a question, I have the following code :

Code: [Select]


    sf::Http http;
    http.SetHost(host);
    sf::Http::Request request(page);
    sf::Http::Response response = http.SendRequest(request);
    sf::Http::Response::Status status = response.GetStatus();
    std::string str;
    if (status == sf::Http::Response::Ok) {
        str = response.GetField("Content-Length");
    } else {
        str = "Request Error.";
    }
    return str.length();


Why does str always contains 0 ?

Sincerly,

Spellbreaker

[Laurent]

Which version of SFML do you use?

[Spellbreaker]

Latest SFML2 SVN Version (1684)

[Laurent]

Can you show me a complete example (including the host name and page requested)?

[Spellbreaker]

Code: [Select]


long DLL_EXPORT getURLContentLength(const char * host, const char * page) {
    sf::Http http;
    http.SetHost(host);
    sf::Http::Request request(page);
    sf::Http::Response response = http.SendRequest(request);
    sf::Http::Response::Status status = response.GetStatus();
    std::string str;
    if (status == sf::Http::Response::Ok) {
        str = response.GetField("Content-Length");
    } else {
        str = "Request Error.";
    }
   std::cout << str;
}


This is the Function, the call is :

getURLContentLenght("http://www.sfml-dev.org", "features.php");

If I request the Pages Content, it works correctly, but I simply don't get the content-length.

I want do modify that function to only request the header, then getting the Content-Lenght: Field.

Right now I have to request the whole page once, then get the contentlength by str.length() in C++, and then I have to request the Content again ( with a getURLContent function ).

[Laurent]

It seems like the response from the server doesn't include a content-length field. So there's nothing you can do.

[Spellbreaker]

Ah okay. So the solution would be :

If Status is okay, but lenght = 0, then request the whole page and return the string length, right?

[Laurent]

Probably. But requesting the page every time you call one of your functions is probably not the most efficient strategy. You should probably request it once (either header or full body) and then call functions that extract information from the received page.

[Spellbreaker]

Yeah I know, but can I load the page once and store it in a struct inside of the DLL? I thought the information gets lost after the external function call returns to WME...

[Laurent]

I thought the information gets lost after the external function call returns to WME...

WME?
If you allocate a structure with new, it won't get destroyed until you call delete. You just have to make sure that both happen in the same module (either the caller or the DLL).

This is usually what C APIs do, together with an opaque pointer:

Code: [Select]

header
------

struct HttpResource; // client doesn't have to know what is inside this structure

DLL_EXPORT HttpResource* get(const char* url);

DLL_EXPORT size_t contentLength(HttpResource* resource);

DLL_EXPORT const char* body(HttpResource* resource);

...

DLL_EXPORT void destroy(HttpResource* resource);



implementation
--------------

struct HttpResource
{
    sf::Http::Response response;
};

HttpResource* get(const char* url)
{
    sf::Http host(...);
    HttpResource* resource = new HttpResource;
    resource->response = host.SendRequest(url);
    return resource;
}

size_t contentLength(HttpResource* resource)
{
    return resource->response.GetField("content-length");
}

const char* body(HttpResource* resource)
{
    return resource->response.GetBody().c_str();
}

...

void destroy(HttpResource* resource)
{
    delete resource;
}

[Spellbreaker]

Damn sorry, I got WME and SFML mixed up. But thanks anyway

The problem with the external DLL call resides in WME, I asked the wrong guy here