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ALogger#

A logger class.

Header:#include <AUI/Logging/ALogger.h>
CMake:aui_link(my_target PUBLIC aui::core)

Detailed Description#

Logger is used for journaling application events like errors or some user actions.

It provides some extra functions like logging to file and output formatting.

It provides std::cout-like API.

Example: 

ALogger::info("MyApp") << "Hello world!";
Possible output: 
[00:47:02][UI Thread][Logger][INFO]: Hello world!

It's convenient to define LOG_TAG variable for your class: 

static constexpr auto LOG_TAG = "MyDownloader";
class MyDownloader {
public:
  void someAction() {
    ALogger::info(LOG_TAG) << "someAction() called";
  }
  void downloadFile(const AString& name) {
    ALogger::info(LOG_TAG) << "Downloading file: " << name;
  }
}

Examples#

examples/7guis/cells/src/Formula.cpp

7GUIs Cells — Spreadsheet processor (Excel).

                return "#{}!"_format(e.getMessage());
            }
        };
    } catch (const AException& e) {
        ALogger::err("Formula") << "Can't parse expression " << expression << "\n" << e;
        return [msg = e.getMessage()](const Spreadsheet&) { return "#{}!"_format(msg); };
    }
}
examples/basic/hello_world/src/main.cpp

Console Hello World Example — Basic CLI Hello World application.

static constexpr auto LOG_TAG = "MyApp";

AUI_ENTRY {
    ALogger::info(LOG_TAG) << "Hello world!";
    return 0;
}
examples/ui/embedded_sdl/src/main.cpp

SDL3 — This code demonstrates how to integrate the AUI Framework with SDL3 to create a window with OpenGL rendering.

AUI_ENTRY {
    /// [SDL_Init]
    if (!SDL_Init(SDL_INIT_VIDEO)) {
        ALogger::err("SDL3") << SDL_GetError();
        return 1;
    }
    /// [SDL_Init]

    /// [CreateWindow]
examples/app/notes/src/main.cpp

Notes App — Note taking app that demonstrates usage of AListModel, AProperty, user data saving and loading.

                return;
            }
            aui::from_json(AJson::fromStream(AFileInputStream("notes.json")), mNotes);
        } catch (const AException& e) {
            ALogger::info(LOG_TAG) << "Can't load notes: " << e;
        }
    }
    /// [load]

    /// [save]
examples/ui/contacts/src/main.cpp

AUI Contacts — Usage of AUI_DECLARATIVE_FOR to make a contacts-like application.

                                return groupLetter(lhs->displayName) == groupLetter(rhs->displayName);
                            }), AVerticalLayout) {
            auto firstContact = *ranges::begin(group);
            auto firstLetter = groupLetter(firstContact->displayName);
            ALogger::info("Test") << "Computing view for group " << AString(1, firstLetter);
            return Vertical {
                Label { firstLetter } AUI_OVERRIDE_STYLE {
                                        Opacity(0.5f),
                                        Padding { 12_dp, 0, 4_dp },
                                        Margin { 0 },
examples/ui/views/src/ExampleWindow.cpp

Views Example — All-in-one views building example.

                                                       "Title",
                                                       "Message",
                                                       AMessageBox::Icon::NONE,
                                                       AMessageBox::Button::OK);
                                     ALogger::info("Example") << "Response: " << int(response);
                                     /// [AMessageBox]
                                 }),
                    _new<AButton>("Cause assertion fail")
                        .connect(&AView::clicked, this, [&] { AUI_ASSERT_NO_CONDITION("assertion fail"); }),
                    _new<AButton>("Cause hang")

Public Types#

Level#

enum ALogger::Level

Constant Description
Level::INFO
Level::WARN
Level::ERR
Level::DEBUG
Level::TRACE

LogWriter#

struct ALogger::LogWriter

Empty structure.

Public Methods#

constructor#

ALogger::ALogger(AString filename)

Constructor for an extra log file.

Arguments
filename
file name

For the global logger, use ALogger::info, ALogger::warn, etc...

Examples:

doLogFileAccessSafe#

template<aui::invocable Callable >
void ALogger::doLogFileAccessSafe(Callable action)

Allows to perform some action (access safely) on log file (which is opened all over the execution process)

Useful when sending log file to remote server.

On Windows, for instance, doesn't allow to read the file when it's already opened.

log#

LogWriter ALogger::log(Level level, AStringView prefix)

Writer a log entry with LogWriter helper.

Arguments
level
level
prefix
prefix

setLogFile#

void ALogger::setLogFile(APath path)

Sets log file.

Arguments
path
path to the log file.

Log file is opened immediately in setLogFile.

If you want to change the log file of ALogger::global(), consider using ALogger::setLogFileForGlobal instead. ALogger::global().setLogFile(...) expression would cause the default log file location to open and to close immediately, when opening a log file in the specified location, causing empty file and two Log file: entries.

setLogFileForGlobal#

static void ALogger::setLogFileForGlobal(APath path)

Sets log file for ALogger::global().

Arguments
path
path to the log file. See also: `ALogger::setLogFile`.