sendGenericCommand()

Purpose

Provides a generic interface for executing custom Electron-side functionality from within the pipeline configuration.

By specifying a command name in the stage configuration, functionality implemented in the Electron application can be invoked directly from configuration files. This enables the Config Editor to access Electron-specific features without requiring dedicated pipeline stages for each use case.

The stage is intended as a flexible extension mechanism that allows new Electron features to be added and made available to configurations with minimal changes to the existing pipeline system.

Typical use cases include:

• Accessing local hardware
• Reading or writing files
• Opening native dialogs
• Generating PDFs or reports
• Interacting with external applications
• Executing custom utility functions
• Exchanging data between the pipeline and Electron

Location

src/app/services/genericStages/generic-stages.service.ts

Signature

sendGenericCommand(
  pipelineConfig: PipelineStageConfig
): OperatorFunction<StatusObject, Observable<any>>

Parameters

Returns

OperatorFunction<StatusObject, Observable<any>>

RxJS operator which executes a custom Electron command and optionally stores the returned result in the application state.

Command Configuration

The stage uses values from:

pipelineConfig.stageConfig.commandParameters

Supported Parameters

Example Configuration

{
  "commandParameters": {
    "commandName": "generateMeasurementReport",
    "fromResKey": "MEASUREMENT_RESULT",
    "fromResGroup": "persistentValues",
    "toResKey": "PDF_PATH",
    "toResGroup": "persistentValues"
  }
}

Workflow

Read command configuration
        ↓
Read transferVariable (optional)
        ↓
Build transferData
        ↓
Execute Electron command
        ↓
Receive result
        ↓
Store result (optional)
        ↓
Execute onSuccess

Transfer Data Handling

The function supports two types of transfer data.

Constant Transfer Data

A fixed value defined in the configuration:

{
  "transferConstant": "exampleValue"
}

State-Based Transfer Data

A value read from the current application state:

{
  "fromResKey": "SCANNER_SERIAL",
  "fromResGroup": "persistentValues"
}

Result:

transferVariable =
  state.persistentValues.SCANNER_SERIAL;

Generated Transfer Object

const transferData = {
  transferConstant,
  transferVariable
};

This object is passed to the Electron command handler.

Electron Command Execution

await this.scannerApiService.executeGenericCommand(
  pipelineConfig.state.persistentValues,
  command,
  transferData
);

Parameters

State Dependencies

Reads

Optional:

state[fromResGroup][fromResKey]

Always:

state.persistentValues

Writes

Optional:

state[toResGroup][toResKey]

Success Behaviour

On successful execution:

1. The configured Electron command is executed.
2. A result is returned by the Electron application.
3. The result is optionally written to the configured state location.
4. The configured onSuccess event target is executed.

pipelineConfig.executeStage(
  pipelineConfig.stageConfig.eventTargets?.onSuccess,
  'onSuccess',
  pipelineConfig.stage
);

Error Behaviour

An error is triggered when:

• No command name is configured.
• The command handler cannot be found.
• The Electron command throws an exception.
• Communication between the application and Electron fails.

In these cases the configured onError event target is executed.

pipelineConfig.executeStage(
  pipelineConfig.stageConfig.eventTargets?.onError,
  'onError',
  pipelineConfig.stage
);

Example 1: Generate a PDF Report

{
  "commandParameters": {
    "commandName": "generateMeasurementReport",
    "fromResKey": "MEASUREMENT_RESULT",
    "fromResGroup": "persistentValues",
    "toResKey": "PDF_PATH",
    "toResGroup": "persistentValues"
  }
}

Result:

persistentValues: {
  PDF_PATH: "/reports/report_001.pdf"
}

Example 2: Open a Native File Dialog

{
  "commandParameters": {
    "commandName": "selectOutputDirectory",
    "toResKey": "OUTPUT_DIRECTORY",
    "toResGroup": "persistentValues"
  }
}

Result:

persistentValues: {
  OUTPUT_DIRECTORY: "C:/Users/Oliver/Documents"
}

Notes

• This stage acts as the primary extension point between the Config Editor and the Electron application.
• New Electron functionality can be made available to configurations by implementing a new command handler without modifying the pipeline framework.
• Input and output state mappings are optional.
• The stage itself contains no Electron-specific business logic and delegates execution to the command handling infrastructure.
• Missing commandName immediately triggers the configured onError event.
• Commands may return any serializable data type which can then be stored in the application state.