Template Generator

templateGen.js

const template = require('./template.json');


class TemplateGenerator {
	constructor(template, prefix = '') {
		if (!template) {
			throw new Error('Template is required');
		}
		this.prefix = prefix;
		this.template = template;
	}
	isPrimitive(attr) {
		return typeof attr === 'string' || typeof attr === 'number';
	}
	isNull(attr) {
		return attr === null || attr === undefined;
	}
	generateTemplate(keyPrefix, templateJson) {
		if (this.isPrimitive(templateJson)) {
			return typeof templateJson;
		}
		const keys = Object.keys(templateJson);
		const templateObj = {};
		keys.forEach(key => {
			const value = templateJson[key];
			const newKey = `${keyPrefix}${ key !== '_id' ? '_' : '' }${key}`;
			if (this.isPrimitive(value)) {
				if (typeof value === 'number' && value > 32768) {
					templateObj[newKey] = 'double';
				} else {
					templateObj[newKey] = typeof value;
				}
			} else if (this.isNull(value)) {
				templateObj[newKey] = 'string';
			} else if (value instanceof Array && value.length) {
				templateObj[newKey] = [this.generateTemplate(newKey, value[0])];
			}	else if (typeof value === 'object') {
				templateObj[newKey] = this.generateTemplate(newKey, value);
			}
		});
		return templateObj;
	}
	generate() {
		const { prefix, template } = this;
		return this.generateTemplate(prefix, template);
	}
}

const templateObj = new TemplateGenerator(template, '__')
console.log(JSON.stringify(templateObj.generate()));