ajaxDBQuery.js

'use strict';

function ajaxDBQuery(element, callback = () => { }) {
	
	console.log("ajaxDBQuery");

	if (element.dataset.url == null || element.dataset.db == null || element.dataset.table == null || element.dataset.columns == null) {
		element.innerText = "400 (Bad Request)";
		return;
	}

	const xhr = new XMLHttpRequest(),
		method = "POST",
		url = element.dataset.url;
	var data = {
		"db": element.dataset.db,
		"table": element.dataset.table,
		"columns": element.dataset.columns,
		"inner_join": element.dataset.inner_join,
		"where": element.dataset.where,
		"order_by": element.dataset.order_by,
		"direction": element.dataset.direction,
		"limit": parseInt(element.dataset.limit, 10),
		"offset": parseInt(element.dataset.offset, 10)
	};
	var data = JSON.stringify(data);

	xhr.open(method, url, true);
	xhr.setRequestHeader('Content-Type', 'application/json');

	xhr.onreadystatechange = function () {
		if (this.readyState === XMLHttpRequest.DONE) {
			if (this.status == 200) {
				// retrieve data
				callback(element, this.responseText);
			} else if (this.status >= 500) {
				// internal server error
				element.innerText = this.statusText;
			} else if (this.status >= 402 && this.status <= 420) {
				// error
				element.innerText = this.statusText;
			} else if (this.status == 400 || this.status == 401) {
				// bad request & unauthorized error
				element.innerText = this.statusText;
			}
		}
	}
	xhr.send(data);

}

export default ajaxDBQuery;