Add for plugins a "minimum required backend" version number?

[mStirner]

Similar to a "node" field in package.json.
If the backend version does not match then number/semver expression, the plugin is not be loaded.

This all could be done in the .init function in plugins. Defined here:

backend/components/plugins/class.plugin.js

Lines 42 to 79 in d1edd64

	let init = (dependencies, cb) => {
	try {
	const granted = dependencies.every((c) => {
	if (this.intents.includes(c)) {
	return true;
	} else {
	logger.warn(`Plugin ${this.uuid} (${this.name}) wants to access not registerd intens "${c}"`);
	return false;
	}
	});
	if (granted) {
	let components = dependencies.map((name) => {
	return require(path.resolve(process.cwd(), `components/${name}`));
	});
	cb(this, components);
	return init;
	} else {
	throw new Error(`Unregisterd intents access approach`);
	}
	} catch (err) {
	logger.error(err, `Plugin could not initalize!`, err.message);
	throw err;
	}
	};

[mStirner]

    constructor(obj) {

        Object.assign(this, obj);
        this._id = String(obj._id);

        Object.defineProperty(this, "logger", {
            value: logger.create(`plugins/${this.uuid}`),
            configurable: false,
            enumerable: false,
            writable: false
        });

        try {

            let file = path.resolve(process.cwd(), "plugins", this.uuid, "package.json");

            let content = fs.readFileSync(file);
            let json = JSON.parse(content);

            Object.defineProperty(this, "package", {
                value: json,
                configurable: false,
                enumerable: false,
                writable: false,
            });

        } catch (err) {
            if (err.code === "ENOENT") {

                this.logger.warn(err, `package.json for plugin "${this.name}" not found. It may work not properly or breaks something!`);

            } else {

                this.logger.warn(err);

            }
        }
    }

[mStirner]

The backend property should be changed from a single string, into a object. e.g:

{
  "name": "plugin-boilerplate",
  "private": "true",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "openhaus": {
    "backend": ">=3.2.1"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 0",
    "build": "grunt build",
    "compress": "grunt compress",
    "checksum": "grunt checksum",
    "release": "grunt release"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/mStirner/plugin-boilerplate.git"
  },
  "author": "Marc Stirner <marc.stirner@open-haus.io>",
  "license": "MIT",
  "bugs": {
    "url": "https://github.com/mStirner/plugin-boilerplate/issues"
  },
  "homepage": "https://github.com/mStirner/plugin-boilerplate#readme",
  "devDependencies": {
    "grunt": "^1.6.1",
    "grunt-contrib-uglify": "^5.2.2",
    "grunt-env": "^1.0.1"
  }
}