SaveData Command

Persistence command that saves a DataManager object to disk via the LoaderRegistry

Overview

SaveData is a non-undoable command that saves a data object from DataManager to disk. It dispatches through LoaderRegistry::trySave(), enabling save operations to participate in command sequences and triage pipelines.

Source files:

  • src/Commands/IO/SaveData.hpp / .cpp
  • src/Commands/IO/SaveData.test.cpp

All code lives in the commands namespace with no Qt dependency.

Parameters

struct SaveDataParams {
    std::string data_key;                          // Key in DataManager
    std::string format;                            // e.g., "csv", "capnproto", "opencv"
    std::string path;                              // Output file/directory path
    std::optional<rfl::Generic> format_options;    // Format-specific options (optional)
};
Field Description
data_key Key of the data object in DataManager to save
format Output format identifier matching a registered IFormatLoader (e.g., "csv", "capnproto", "opencv")
path Full output file path (or directory, depending on saver)
format_options Optional JSON object with format-specific saver options (delimiter, header, etc.)

Supported Types

Any data type registered in the LoaderRegistry saver infrastructure:

  • PointData (CSV)
  • LineData (CSV single-file, CSV multi-file, CapnProto)
  • MaskData (CSV RLE, OpenCV image)
  • AnalogTimeSeries (CSV)
  • DigitalEventSeries (CSV)
  • DigitalIntervalSeries (CSV)

Undo

Not undoable (isUndoable() returns false). File writes cannot be reversed.

Execution Flow

  1. Look up the data type via DataManager::getType(data_key) → DM_DataType.
  2. Convert to DM_DataType via toDM_DataType().
  3. Extract the raw void const * pointer from DataManager::getDataVariant().
  4. Convert format_options (if present) from rfl::Generic to nlohmann::json.
  5. Dispatch through LoaderRegistry::getInstance().trySave().
  6. Return CommandResult::ok() on success, CommandResult::error() on failure.

Error Cases

Condition Error message
data_key not found "Data key '<key>' not found in DataManager"
Data variant is null "Data pointer for key '<key>' is null"
format_options fails to parse "Failed to parse format_options as JSON"
No registered saver for format/type Error from LoaderRegistry::trySave()

JSON Example

{
    "command_name": "SaveData",
    "parameters": {
        "data_key": "whisker_1",
        "format": "csv",
        "path": "/data/output/whisker_1.csv",
        "format_options": {
            "delimiter": ",",
            "save_header": true
        }
    }
}

Pipeline Example

Save data as the final step in a triage pipeline using ForEachKey:

{
    "commands": [
        {
            "command_name": "ForEachKey",
            "parameters": {
                "items": ["whisker_1", "whisker_2"],
                "variable": "key",
                "commands": [
                    {
                        "command_name": "SaveData",
                        "parameters": {
                            "data_key": "${key}",
                            "format": "csv",
                            "path": "/data/output/${key}.csv"
                        }
                    }
                ]
            }
        }
    ]
}

Tests

11 test cases in SaveData.test.cpp covering:

  • Factory tests: creation from valid params, with format_options, invalid params, isKnownCommandName
  • Execution tests: successful CSV save, round-trip verification, unknown key error, unsupported format error
  • Serialization: toJson() round-trip
  • Integration: factory-based command sequence, getCommandInfo metadata