core

@open-pioneer/core

This package contains basic utility functions and classes used in Open Pioneer Trails applications.

Events

The package exports the EventEmitter class that supports emitting and subscribing to user defined events.

Usage

Errors

The Error class extends JavaScript's global error class with a user defined id value that can be used to explicitly identify error conditions.

import { Error } from "@open-pioneer/core";
throw new Error("my-error:identifier", "This is the error message");

Error also exposes the optional cause attribute that allows nesting of error instances. Note that browser support for that property is still required:

import { Error, getErrorChain } from "@open-pioneer/core";

try {
    someFunctionThatCanThrow();
} catch (e) {
    throw new Error("my-error:higher-level-error-id", "Error text", { cause: e });
}

// getErrorChain gathers the error and all its causes (if any) into an array:
const errors = getErrorChain(error);

Resources

The Resource type exported from this package is used by objects with a destructor. All object needing some cleanup action to be called should use the destroy method for consistency and easier handling.

Logger

The 'Logger' class provides a logger for standardized application wide logging. The log level is configured globally in the file vite.config.js.

To create a logger instance, call the createLogger method. It takes a prefix (string) to prepend to each message. To encode hierarchical names, use : as a separator (for example "some-package:SomeClass").

The logger provides log methods for the following log levels with the following order: DEBUG < INFO < WARN < ERROR.

For example (as class attribute):

import { createLogger, Logger } from "@open-pioneer/core";

export class LoggerTestExample {
    private logger: Logger;
    constructor() {
        this.logger = createLogger("example-package:LoggerTestExample");
    }

    testMethod() {
        this.logger.warn("example message", { testLog: 123, text: "this is a text" });
    }
}

Or as a shared logger at module scope:

import { createLogger } from "@open-pioneer/core";
const LOG = createLogger("example-package");

License

Apache-2.0 (see LICENSE file)