form-copypasta-crx/content.js

chrome.runtime.onMessage.addListener(function(message, sender, sendResponse) {
	switch (message.action) {
		case "copy":
			const result = copyFormElementValues(document.activeElement);
			sendResponse(result);
			break;
		case "paste":
			pasteFormElementValues(document.activeElement, message.formData, false);
			break;
		case "paste2":
			pasteFormElementValues(document.activeElement, message.formData, true);
			break;
		default: break;
	}
});




function copyFormElementValues(el) {
	const container = getContainer(el);
	if (container == null) {
		writeLog("Form container not found");
		return null;
	}

	const result = getFormElementValueSet(container, "input", "select", "textarea");

	console.log(result);

	return result;
}

function pasteFormElementValues(el, formData, includeHidden) {
	if (String.isNullOrUndefined(formData)) {
		return;
	}

	let container = getContainer(el);
	if (container == null) {
		writeLog("Form container not found");
		return;
	}

	for (let key in formData) {
		if (String.isNullOrWhitespace(key)) {
			continue;
		}

		const dataType = Object.getDataType(formData[key]);
		if (dataType == "object") {
			continue;
		}

		const foundEls = container.querySelectorAll("[name='" + key + "']");
		if (foundEls.length <= 0) {
			continue;
		}

		if (dataType == "array") {
			setFormElementValues(foundEls, formData[key], includeHidden);
		} else {
			for (let x=0; x<foundEls.length; x++) {
				setFormElementValue(foundEls[x], formData[key], includeHidden);
			}
		}
	}

	writeLog("Pasted");
}


/**
 * Get node container.
 */
function getContainer(node) {
	let result = node;

	if (result.nodeName.toLocaleLowerCase() == "iframe") {
		writeLog("iFrame found");

		result = getIFrameFormNode(document.activeElement);
	} else {
		result = getParentFormNode(document.activeElement);
		if (result == null) {
			writeLog("No form found");

			result = node.parentNode;
		} else {
			writeLog("Form found");
		}
	}

	return ((typeof(result) == "undefined") ? null : result);
}

/**
 * Get parent form node.
 */
function getParentFormNode(node) {
	let result = node;

	// Special case, look inside iframe.
	if (result.nodeName.toLocaleLowerCase() == "iframe") {
		return null;
	}

	while (true) {
		if (String.isNullOrUndefined(result)) {
			result = null;
			break;
		}

		if (result.nodeName.toLocaleLowerCase() == "form") {
			break;
		}

		result = result.parentNode;
	}

	return result;
}

/**
 * Get form node in iframe.
 */
function getIFrameFormNode(node) {
	if (node.nodeName.toLocaleLowerCase() != "iframe") {
		return null;
	}

	const foundEls = (node.contentDocument || node.contentWindow).getElementsByTagName("form");
	if (foundEls.length <= 0) {
		return null;
	}

	return foundEls[0];
}

/**
 * Get form element values.
 */
function getFormElementValueSet(form, ...tagNames){
	let result = { };

	for (let x=0; x<tagNames.length; x++) {
	  let els = form.getElementsByTagName(tagNames[x]);

		for (let i=0; i<els.length; i++) {
			let newValue = null;

			if (String.isNullOrWhitespace(els[i].name)) {
				continue;
			}

			switch (els[i].type)
			{
				case "checkbox":
				case "radio":
					newValue = els[i].checked;
					break;
				// case "hidden":
				// 	continue;
				case "submit":
					continue;
				default:
					newValue = els[i].value;
					break;
			}

			if (newValue === null) {
				continue;
			}

			if (result[els[i].name]) {
				// Convert single to array
				if (Object.getDataType(result[els[i].name]) != "array") {
					result[els[i].name] = [result[els[i].name]];
				}

				result[els[i].name].push(newValue);
			} else {
				result[els[i].name] = newValue;
			}
		}
	}

	return result;
}

/**
 * Set single form element value.
 */
function setFormElementValue(el, value, includeHidden) {
	switch (el.type) {
		case "hidden":
			if (includeHidden === true) {
				el.value = value;
			}

			break;
		case "checkbox":
		case "radio":
			el.checked = value;
			break;
		case "submit":
			break;
		default:
			el.value = value;
			break;
	}
}

/**
 * Set form element value from an array of values.
 */
function setFormElementValues(els, values, includeHidden) {
	for (let i=0; i<Math.min(els.length, values.length); i++) {
		setFormElementValue(els[i], values[i], includeHidden);
	}
}

/**
 * Write log to console.
 */
function writeLog(message) {
	console.log("Form Copypasta > " + message);
}




Object.getDataType = function(value) {
	if (String.isNullOrUndefined(value)) {
		return "null";
	}

	if (typeof(value) == "object") {
		if (Array.isArray(value)) {
			return "array";
		} else {
			return "object";
		}
	}

	return typeof(value);
};

String.isNullOrUndefined = function(value) {
  if (typeof (value) == "undefined") {
    return true;
  }

  if (value == null) {
    return true;
  }

  return false;
};

String.isNullOrWhitespace = function(value) {
  const a = this;

  if (String.isNullOrUndefined(value)) {
    return true;
  }

  if (typeof(value) == "string") {
    return (value.trim().length <= 0);
  } else {
    return (value.toString().trim().length <= 0);
  }
};