jQuery Demo: Mad Libs Word Game

<div id="madlibs">

	<p>
		<span rel="madlib" type="noun" desc="A girl's name.">Sally</span> wend over to
		<span rel="madlib" type="noun" desc="A boy's name.">Luke</span> and grabbed his
		<span rel="madlib" type="noun" desc="A body part.">hand</span>. "Come on", she said, we have to
		<span rel="madlib" type="verb" desc="A way to get from here to there.">run</span> to the
		<span rel="madlib" type="noun" desc="A place.">lunch room</span> where we can eat lots of
		<span rel="madlib" type="noun" desc="A food.">sandwhiches</span>! I
		<span rel="madlib" type="adverb" desc="How you feel about something.">hate</span> those, he said, I would much rather
		<span rel="madlib" type="verb" desc="Something you can do with your mouth.">eat</span> dog poop!
	</p>

</div>

// This will fire when the document is ready.
$(
	function(){

		// Get a pointer to the mad libs container.
		jMadLibsContainer = $( "#madlibs" );

		// Get all of the madlib elements (defined by Span
		// objects with the rel=madlib).
		jMadLibs = $( "span[@rel='madlib']" );

		// Create a form element and wire up the onsubmit
		// to fire the show mad libs and then return false
		// so that the form doesn't submit anywhere.
		jMadLibsForm = $( "<form>" ).submit(
			function(){
			ShowMadLibs();
				return( false );
			}
			);

		// For each of the mad lib elements, we need to
		// create a corresponding form element in our new form.
		// Loop over each element and create the form fields.
		jMadLibs.each(

			// For each of the madlib nodes, we want to update
			// the contents of the mad libs form.
			function( intIndex ){
				var jMadLibsNode = $( this );

				jMadLibsForm.append(
					"<p>" +
					jMadLibsNode.attr( "type" ).toUpperCase() +
					" : " +
					jMadLibsNode.attr( "desc" ) +
					"<br />" +
					"<input type=\"text\" size=\"60\" />" +
					"</p>"
					);

			}
			);

		// Add the submit button to the form.
		jMadLibsForm.append(
			"<p>" +
			"<input type=\"submit\" value=\"Show Mad Libs!\" />" +
			"</p>"
			);


		// Hide the mad lib container.
		jMadLibsContainer.hide();

		// Add the mad libs form after the mad libs container.
		jMadLibsContainer.after(
			jMadLibsForm
			);
	}
	);


// This will be used to process the mad lib form once the
// user had entered all of the values.
function ShowMadLibs(){
	var strErrors = "";

	// Loop over the form elements to make sure that all
	// the values have been entered.
	jMadLibsForm.find( "input" ).each(
		function( intIndex ){
			var jPara = $( this.parentNode );
			var jInput = jPara.find( "input" );

			// Check to see if the form field is empty.
			// If the input is empty, echo the field
			// label and turn the field red.
			if (jInput.val() == ""){

				// Add the error text.
				strErrors += (jPara.text() + "\n");

				// Highlight the field.
				jInput.css( "background-color", "#FFCCCC" );

			} else {

				// This field is fine, make sure that it
				// is not hightlighted.
				// Highlight the field.
				jInput.css( "background-color", "#FFFFFF" );

			}
		}
		);


	// Check to see if we have any errors.
	if (strErrors.length > 0){

		// There were form validation errors. Alert them.
		alert( strErrors );

	} else {

		// There were no form validation errors. Loop over
		// each of the mad lib nodes and set the text.
		jMadLibs.each(
			function( intIndex ){
				var jMadLibsNode = $( this );

				// Set the text of the mad libs node to the
				// form field valud of the input at the
				// same index.
				jMadLibsNode.text(
					jMadLibsForm.find(
						"p:nth-child(" + (intIndex + 1) + ") input"
						).val()
					);
			}
			);

		// Hide the form.
		jMadLibsForm.hide();

		// Show the mad libs.
		jMadLibsContainer.show();

	}
}



// This is a collection that will store references to all of
// our Mad Lib DOM elements.
var jMadLibs = null;

// This is a pointer to the mad libs container. We just need
// something in which we can group all the editable content.
var jMadLibsContainer = null;

// This is a pointer to the mad libs form (yet to be created).
var jMadLibsForm = null;