Javascript to Coffeescript

Question

So I have this javascript That works by itself

function update_checkboxes()
 {
 var part_array = [];
 $("input#edit:checked").parents('td').next().each(function(){
 part_id = $(this).text();
 part_array.push(part_id);
 });
 $("input#participant_ids").val(JSON.stringify(part_array));
 }

That I converted to coffeescript

update_checkboxes = ->
 part_array = []
 $("input#edit:checked").parents("td").next().each ->
 part_id = $(this).text()
 part_array.push part_id
 $("input#participant_ids").val JSON.stringify(part_array)

The problem is when I do rails rake assets:precompile, it compile fine but in Firebug I gives error

ReferenceError: part_array is not defined
$("input#participant_ids").val(JSON.stringify(part_array));

due that the part_array gets defined in a different block.

update_checkboxes = function() {
 var part_array;
 return part_array = [];
 };
 $("input#edit:checked").parents("td").next().each(function() {
 var part_id;
 part_id = $(this).text();
 return part_array.push(part_id);
 });
 $("input#participant_ids").val(JSON.stringify(part_array));
}).call(this); 

What I'm doing wrong here?

• apneadiving: maybe your inconsistent tabs? (4 spaces under update_checkboxes), then you use 2
• spartikus: I would say your indention is off, this script looks good to me

Answer 1

Remember that in CoffeeScript, indentation matters, and you can't mix spaces and tabs reliably.

This CoffeeScript, in which indentation has been standardized to two spaces:

update_checkboxes = ->
 part_array = []
 $("input#edit:checked").parents("td").next().each ->
 part_id = $(this).text()
 part_array.push part_id
 $("input#participant_ids").val JSON.stringify(part_array)

Results in this JavaScript:

var update_checkboxes;
update_checkboxes = function() {
 var part_array;
 part_array = [];
 $("input#edit:checked").parents("td").next().each(function() {
 var part_id;
 part_id = $(this).text();
 return part_array.push(part_id);
 });
 return $("input#participant_ids").val(JSON.stringify(part_array));
};

...which doesn't end up with part_array defined in a separate block.

Answer 2

Your indentation must be off. I pasted your exact coffeescript from the question into js2coffee

update_checkboxes = ->
 part_array = []
 $("input#edit:checked").parents("td").next().each ->
 part_id = $(this).text()
 part_array.push part_id
 $("input#participant_ids").val JSON.stringify(part_array)

and received...

var update_checkboxes;
update_checkboxes = function() {
 var part_array;
 part_array = [];
 $("input#edit:checked").parents("td").next().each(function() {
 var part_id;
 part_id = $(this).text();
 return part_array.push(part_id);
 });
 return $("input#participant_ids").val(JSON.stringify(part_array));
};

Which is correct. StackOverflow must have normalized your indentation when you pasted it. Take a look at the original and fix the mismatched indentation.