Introduction

QNetworkAccessManager can not be used in a QThread by design, that is where qcurl comes in handy. You can use do Network Access in a intuitive way.

Installation

Linux

$ git clone https://github.com/klesh/libqcurl.git
$ cd libqcurl
& mkdir builds && cd builds
$ qmake .. && make && sudo make install
$ pkg-config --libs libqcurl

Usage

Simple cases

#include <QtTest>
#include "qcurl.h"

int main() {
    // post empty body
    auto res = QCurl::post(QUrl("http://localhost:7880/echo"));
    QCOMPARE(res.statusCode(), 200);

    // post plain text
    auto res2 = QCurl::post(QUrl("http://localhost:7880/echo"), "foobar");
    QCOMPARE(res2.statusCode(), 200);
    QCOMPARE(res2.responseText(), "foobar");

    // post regular form
    QCurlForm form;
    form.append({"hello", "world"});
    auto res3 = QCurl::post(QUrl("http://localhost:7880/form"), form);
    QCOMPARE(res3.responseText(), "world");

    // post and receive json
    QJsonObject postRoot;
    postRoot.insert("username", "foobar");
    postRoot.insert("password", "helloworld");
    QCurlJson postJson(postRoot);
    auto res4 = QCurl::post(QUrl("http://localhost:7880/json"), postJson);
    auto resJson = res4.responseJson();
    QCOMPARE(res4.statusCode(), 200);
    auto root = resJson.object();
    QCOMPARE(root["code"].toString(), "SUCCESS");
    auto data = root["data"].toObject();
    QCOMPARE(data["username"].toString(), "foobar");
    QCOMPARE(data["password"].toString(), "helloworld");

    // upload file by multipart
    QCurlMultipart parts;
    parts.append({"filename", "plaintextfile.txt"});

    QByteArray bytes = QString("hello world").toUtf8();
    QBuffer buffer(&bytes);
    buffer.setProperty("filename", "plaintextfile.txt");
    parts.append({"file", QVariant::fromValue(&buffer)});
    auto res5 = QCurl::post(QUrl("http://localhost:7880/parts"), parts);
    QCOMPARE(res5.statusCode(), 200);
    QCOMPARE(res5.responseText(), "plaintextfile.txt\nhello world");

    QBuffer buffer2(&bytes);
    auto res6 = QCurl::post(QUrl("http://localhost:7880/raw"), buffer2);
    QCOMPARE(res6.statusCode(), 200);
    QCOMPARE(res6.responseText(), "hello world");

    return 0;
}

Download as file

#include <QtTest>
#include "qcurl.h"

int main() {
    QCurl curl(QUrl("http://localhost:7880/"));
    QTemporaryFile file;
    auto req = curl.request();
    auto res = req.perform("GET", "hello.txt", &file);
    file.seek(0);
    QCOMPARE(file.readAll(), "hello world");
}

Calling on APIs

#include <QtTest>
#include "qcurl.h"

int main() {
    QCurl apiClient(QUrl("http://localhost:7880/api/")); // ending with slash is essential
    apiClient.setHeader("Authorization", "Bearer xxxx");

    auto usersRes = apiClient.get("users");
    auto users = usersRes.responseJson();
    // do sth with users

    auto userDetailRes = apiClient.get("users/123");
    auto userDetail = userDetailRes.responseJson(); 
    // do sth with userDetail
}

FTP/SFTP

#include <QtTest>
#include "qcurl.h"

int main() {
    QCurl curl(QUrl("ftp://ftpuser:ftppass@localhost:7881/"));
    QByteArray bytes = QString("this is a test").toUtf8();
    QBuffer buffer(&bytes);
    auto putRes = curl.put("foobar.txt", buffer);
    QCOMPARE(putRes.code(), CURLE_OK);

    auto getRes = curl.get("foobar.txt");
    QCOMPARE(getRes.responseText(), "this is a test");

    auto delRes = curl.dele("foobar.txt");

    QCOMPARE(curl.exists("foobar.txt"), 0);
}

How to run compile/test on Windows with MinGW

1. Download curl source code from https://curl.haxx.se/windows/
2. Download deps you need (openssl, libssh2 is required) from https://windows.php.net/downloads/php-sdk/deps/vs16
3. Extract curl to some place , e.g. D:\Projects\curl, so all curl source code should be in D:\Projects\curl\curl-7.65.3 or something like that.
4. Create folder D:\Projects\curl\deps, and extract deps of your choice into it. This folder should contains bin include and lib folders. beware openssl might have its DLLs in its root folder while others have them in bin folder, you'd better copy those DLLs to bin as well.
5. Open Developer Command Prompt for VS and go to D:\Projects\curl\curl-7.65.3\winbuild to build. For test I suggest follwing command: nmake /f Makefile.vc mode=dll WITH_SSH2=dll WITH_ZLIB=static MACHINE=x86
6. Some folder like D:\Projects\curl\curl-7.65.3\builds\libcurl-vc-x86-release-dll-zlib-static-ssh2-dll-ipv6-sspi-winssl should be created. Now, copy bin include lib to D:\Projects\curl\deps. So it becomes the deps folder we need for our tests
7. Clone libqcurl into some directory, Copy deps\* folder to somedirectory\deps\selfbuild\i386 folder, along side with libqcurl and tests folder. The project directory structure should look like:

   somedirectory\
    |_doc
    |_libqcurl
    |_test
    |
    |_deps
      |_selfbuild
        |_i386
          |_ lib
          |_ include
          |_ bin
        |_x86_64
          |_ lib
          |_ include
          |_ bin

8. Build and run libqcurl with Qt Creator