Using the Error Framework¶

Syntax in a C++ module¶

You can find two example modules written in C++ in the examples folder: ExampleErrorRaiser and ExampleErrorSubscriber.

Raise an error¶

Can be done in the implementation of an interface.

// Create an error object
Error error_object = this->error_factory->create_error(
    "example/ExampleErrorA",    // ErrorType
    "",                         // ErrorSubType
    "This is an example error"  // message
);
// Raise the error
raise_error(error_object);

Clear an error¶

Can be done in the implementation of an interface.

// Clear all errors of the ErrorType "example/ExampleErrorA"
clear_error(
    "example/ExampleErrorA",    // ErrorType
    true                        // clear_all
);

// Clear the error with ErrorType "example/ExampleErrorA" and ErrorSubType ""
clear_error(
    "example/ExampleErrorA",    // ErrorType
    ""                          // ErrorSubType
);
clear_error(
    "example/ExampleErrorA",    // ErrorType
    false                       // clear_all
);
clear_error(
    "example/ExampleErrorA"     // ErrorType
);                              // clear_all defaults to false

// Clear all errors of the current implementation
clear_all_errors_of_impl();

The ErrorFactory¶

Is used to create an error object.

Error error_object_0 = this->error_factory->create_error();

Error error_object_1 = this->error_factory->create_error(
    "example/ExampleErrorA",        // ErrorType
    "",                             // ErrorSubType
    "This is an example error"      // message
);

Error error_object_2 = this->error_factory->create_error(
    "example/ExampleErrorA",        // ErrorType
    "",                             // ErrorSubType
    "This is an example error",     // message
    Everest::error::Severity::High  // severity
);

Error error_object_3 = this->error_factory->create_error(
    "example/ExampleErrorA",        // ErrorType
    "",                             // ErrorSubType
    "This is an example error",     // message
    Everest::error::State::Active   // state
);

Error error_object_4 = this->error_factory->create_error(
    "example/ExampleErrorA",        // ErrorType
    "",                             // ErrorSubType
    "This is an example error",     // message
    Everest::error::Severity::High, // severity
    Everest::error::State::Active   // state
);

The ErrorStateMonitor¶

Is used to monitor the error state of implementations and requirements. Can be accessed in the implementation of an interface / anytime for requirements.

Get the ErrorStateMonitor:

// Get the ErrorStateMonitor of an implementation
std::shared_ptr<ErrorStateMonitor>& monitor = this->error_state_monitor;

// Get the ErrorStateMonitor of a requirement
std::shared_ptr<ErrorStateMonitor>& monitor = this->mod->r_example_raiser->error_state_monitor;

Check if an error is active:

// Check if an error of the ErrorType "example/ExampleErrorA" is active
bool is_active = monitor->is_error_active(
    "example/ExampleErrorA",    // ErrorType
    ""                          // ErrorSubType
);

Check if a specific set of errors is in a specific state:

// Check if an error of the ErrorType "example/ExampleErrorA" is active
StateCondition condition = {
    "example/ExampleErrorA",        // ErrorType
    "",                             // ErrorSubType
    true                            // active
};
bool is_satisfied = monitor->is_condition_satisfied(condition);

// Check if multiple errors are active
std::list<StateCondition> conditions = {
    {
        "example/ExampleErrorA",    // ErrorType
        "",                         // ErrorSubType
        true                        // active
    },
    {
        "example/ExampleErrorB",    // ErrorType
        "",                         // ErrorSubType
        true                        // active
    }
};
bool are_satisfied = monitor->is_condition_satisfied(conditions);

Syntax in a Python module¶

You can find two example modules written in Python in the examples folder: PyExampleErrorRaiser and PyExampleErrorSubscriber.

The error related classes need to be imported from the everest module.

from everest.framework import error

Raise an error¶

Can be done in the implementation of an interface after initializing. In opposite to the C++ implementation, the raise function is called on the module object and takes additionally the implementation_id as argument.

# Create an error object
error_object = self._mod.get_error_factory("example_raiser").create_error(
    "example/ExampleErrorA",    # ErrorType
    "",                         # ErrorSubType
    "This is an example error"  # message
)
# Raise the error
self._mod.raise_error(
    "example_raiser",           # implementation_id
    error_object                # error
)

Clear an error¶

Can be done in the implementation of an interface after raising. In opposite to the C++ implementation, the clear function is called on the module object and takes additionally the implementation_id as argument.

# Clear all errors of the ErrorType "example/ExampleErrorA"
self._mod.clear_error(
    "example_raiser",           # implementation_id
    "example/ExampleErrorA",    # ErrorType
    True                        # clear_all
)

# Clear the error with ErrorType "example/ExampleErrorA" and ErrorSubType ""
self._mod.clear_error(
    "example_raiser",           # implementation_id
    "example/ExampleErrorA",    # ErrorType
    ""                          # ErrorSubType
)
self._mod.clear_error(
    "example_raiser",           # implementation_id
    "example/ExampleErrorA",    # ErrorType
    False                       # clear_all
)
self._mod.clear_error(
    "example_raiser",           # implementation_id
    "example/ExampleErrorA"     # ErrorType
)                               # clear_all defaults to false

# Clear all errors of the current implementation
self._mod.clear_all_errors_of_impl(
    "example_raiser"            # implementation_id
)

Subscribe to an error¶

Can be done in the init function of the implementation. In opposite to the C++ implementation, the subscribe function is called on the module object and takes additionally the requirement as argument.

# Subscribe to an error of the ErrorType "example/ExampleErrorA"
self._mod.subscribe_error(
    self._setup.connections["example_raiser"][0],   # requirement
    "example/ExampleErrorA",                        # ErrorType
    lambda error: print("Error raised: ", error),   # callback
    lambda error: print("Error cleared: ", error)   # clear_callback
)

# Subscribe to all errors of the requirement
self._mod.subscribe_all_errors(
    self._setup.connections["example_raiser"][0],   # implementation_id
    lambda error: print("Error raised: ", error),   # callback
    lambda error: print("Error cleared: ", error)   # clear_callback
)

Subscribe to global all errors¶

This feature is currently only available for C++ modules.