form-copypasta-crx/content.js

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {

	const parentForm = getParentFormNode(document.activeElement);
	if (parentForm == null) {
		console.log("Form not found");
		return;
	}

	switch (request.action) {
		case "copy":
			const result = buildFormValueSet(parentForm, "input", "select", "textarea");

			console.log(result);

			sendResponse(result);

			break;
		case "paste":
			delete request.pasteForm;

			// console.log(request);

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

				const dataType = checkDataType(request[key]);
				if (dataType == "object") {
					continue;
				}

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

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

			break;
		default: break;
	}

});




/**
 * Check the data type of the value (string, number, array, object).
 */
function checkDataType(value) {
	if (String.isNullOrUndefined(value)) {
		return "null";
	}

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

	return typeof(value);
}

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

	// Special case, look inside iframe.
	if (result.nodeName.toLocaleLowerCase() == "iframe") {
		const foundForms = (result.contentDocument || result.contentWindow).getElementsByTagName("form");
		if (foundForms.length > 0) {
			return foundForms[0];
		}
	}

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

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

		result = result.parentNode;
	}

	return result;
}

/**
 * Push form element value to array.
 */
function buildFormValueSet(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;

			switch (els[i].type)
			{
				case "hidden":
					// Do nothing
					break;
				case "checkbox":
					newValue = els[i].checked;
					break;
				case "radio":
					newValue = els[i].checked;
					break;
				default:
					newValue = els[i].value;
					break;
			}

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

			if (result[els[i].name]) {
				// Convert single to array
				if (checkDataType(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) {
	switch (el.type) {
		case "hidden":
			break;
		case "checkbox":
		case "radio":
			el.checked = value;
			break;
		default:
			el.value = value;
			break;
	}
}

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

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);
  }
};