View source for Drag and drop answer option values

== Challenge  ==

In order to be more flexible in displaying questions

As a questionnaire creator 

I want to drag and drop elements in a pre-defined lists to use as question's answers 

'''Example''' 

I want to drag products in left list to textboxes in right list, and have the ability of changing my choices by clicking a Remove link 

[[Image:QuestionTips DragNDrop 1.jpg]] 

[[Image:QuestionTips DragNDrop 2.jpg]] 

[[Image:QuestionTips DragNDrop 3.jpg]]&nbsp;

== Solution ==

*Create a text grid question
*Add a column containing the products to the left of the sub question text column, make the text draggable
*Make an extra space column between product column and sub question text column
*Add a column containing Remove links to the right of the sub question text column
*Make textboxes droppable
*Hide the product in the left grid when it is dropped in the text box, the previous product in the textbox will be shown again in the left list
*Clicking Remove will clear the textbox in the same row and show the corresponding product in the left list

== Code  ==
<source lang="javascript" line="1">
quest.onInit = function()
{
	this.initializeLeftList();
	
	//add Remove link after text boxes
	$("input:text").each(
		function(i)
		{
			$(this).parent().after(
				$("<td>")
					.append($("<a href=\"javascript:quest.clearAnswer("+i+");\">Remove</a>"))
					.addClass("grid_subquestion_text grid_subquestion_odd")
			);
		}
	);
	
	//configure the drag move
	$(".draggable_text").draggable
	(
		{
			mouse: "pointer",
			helper: 'clone'
		}
	);
	
	//make the textboxes droppable and not editable	
	$("input:text").each(
		function(i)
		{
			$(this).addClass("droppable_cell");
			$(this)[0].contentEditable = false;
			$(this).width("300px");
		}
	);

	//drop function
	$(".droppable_cell").droppable
	(
		{
			accept: ".draggable_text",
			activeClass: 'droppable-active',
			hoverClass: 'droppable-hover',
			drop: function(ev, ui) 
			{		
				var currentValue = $(this).val();
				var newValue = ui.draggable.text();
				if (currentValue != "" && currentValue != newValue)
				{
					quest.showProduct(currentValue);	
				}
				$(this).val(ui.draggable.text());	
				ui.draggable._hide("fast");				
			}
		}
	);	
}

quest.initializeLeftList = function()
{
	var n = this.questions.length;
	var answers = this.getAnswers();
	
	var products = new Array();
	products[0] = "{{Brands[0]}}";
	products[1] = "{{Brands[1]}}";
	products[2] = "{{Brands[2]}}";
	products[3] = "{{Brands[3]}}";
	products[4] = "{{Brands[4]}}";	
	
	//add a product cell before the sub question text cell
	
	for(var i=0; i<n; i++)
	{		
		var v = products[i];
		$("#grid_subquestion_text_" + (i+1))
			.before(
					$("<td>").append(
						$("<div>")					
							.append(
								$("<p>").text(v)
									.addClass("draggable_text")
									.css("mouse", "pointer")
							)						
					)
					.width("200px")
			)			
			.width("10px");				
	}
	
	$("#grid_subquestion_text_1")
	.before(
		$("<td rowspan=\""+(n + 1)+"\">&nbsp;</td>")
			.addClass("grid_space_cell")
			.width("200px")
	);
	
	$(".draggable_text").each(
		function(i)
		{
			if (answers.exists($(this).text()))
				$(this)._hide("fast");
		}
	);	
}

//get list of answered value
quest.getAnswers = function()
{
	var a = new Array();
	a[0] = "{{Q7[0]}}";
	a[1] = "{{Q7[1]}}";
	a[2] = "{{Q7[2]}}";
	a[3] = "{{Q7[3]}}";
	a[4] = "{{Q7[4]}}";	
	return a;	
}

//check if a value exists in an array
Array.prototype.exists = function(value)
{
	for(var i=0; i<this.length; i++)
	{
		if (this[i] == value)
			return true;
	}
	return false;
}

//show a product in the left list
quest.showProduct = function(value)
{
	$(".draggable_text").each(
		function(i)
		{
			if ($(this).text() == value)
				$(this).show();
		}
	);
}

//remove a product from the right list and put back in the left list
quest.clearAnswer = function(index)
{
	var input = $("input:text")[index];
	var value = input.value;
	if (value != "")
	{
		this.showProduct(value);
		input.value = "";
	}
}
</source>
== Source  ==
Questionnaire Resource Id on cg.catglobe.com site: 164079 (Question: Q4_Drag_and_drop_answer_option_values)