JavaScript.utils/src/utils/DomHelpers.mjs

/*
Description: DOM Helpers
Date:        2025/3/6
Creator:     Clemens Schwaighofer
*/

export { loadEl, pop, expandTA, exists };

/**
 * Gets html element or throws an error
 * @param {string} el_id Element ID to get
 * @returns {HTMLElement}
 * @throws Error
 */
function loadEl(el_id)
{
	let el = document.getElementById(el_id);
	if (el === null) {
		throw new Error('Cannot find: ' + el_id);
	}
	return el;
}

/**
 * opens a popup window with winName and given features (string)
 * @param {String} theURL   the url
 * @param {String} winName  window name
 * @param {Object} features popup features
 */
function pop(theURL, winName, features)
{
	let __winName = window.open(theURL, winName, features);
	if (__winName == null) {
		return;
	}
	__winName.focus();
}

/**
 * automatically resize a text area based on the amount of lines in it
 * @param {string} ta_id element id
 */
function expandTA(ta_id)
{
	let ta = this.loadEl(ta_id);
	if (ta instanceof HTMLElement && ta.getAttribute('type') !== "textarea") {
		throw new Error("Element is not a textarea: " + ta_id);
	}
	let maxChars = parseInt(ta.getAttribute('cols') ?? "0");
	let ta_value = ta.getAttribute('value');
	let theRows = [];
	if (ta_value != null) {
		theRows = ta_value.split('\n');
	}
	var numNewRows = 0;

	for ( var i = 0; i < theRows.length; i++ ) {
		if ((theRows[i].length+2) > maxChars) {
			numNewRows += Math.ceil( (theRows[i].length+2) / maxChars ) ;
		}
	}
	ta.setAttribute('row', (numNewRows + theRows.length).toString());
}

/**
 * checks if a DOM element actually exists
 * @param  {String}  id Element id to check for
 * @return {Boolean}    true if element exists, false on failure
 */
function exists(id)
{
	return $('#' + id).length > 0 ? true : false;
}

// __END__