jQuery: disables button and swaps text to loading text.

gistfile1.js

// disables button and swaps text to loading text
$.fn.setLoadingState = function (loadingText) {
  if (!loadingText) {
    loadingText = 'Loading...'
  }
  $(this).prop('disabled', true).val(loadingText);
  // allow jQuery chaining
  return this;
};

// Usage
$('#some_button').setLoadingState();
$('#some_button').setLoadingState('Please wait...');