Jade is a technology which is still very much under active development. After the publication of the book there have been some changes which broke the code included in the book, I will be documenting them in the post.

script and style tags

If you use the script and style markers as shown in the book, you will see the warning “Implicit textOnly for `script` and `style` is deprecated. Use `script.` or `style.` instead.”.

The fix is very easy, and is mentioned in the warning message itself – just end the markers with a dot(.).

Replace script with script., and style with style..

What used to be

script
  var greeting = 'Welcome to Jade';

would now become

script.
  var greeting = 'Welcome to Jade';

What used to be

style(type='text/css')
  #wrapper { padding: 0 }

would now become

style(type='text/css').
  #wrapper { padding: 0 }

while loop

The example of while loop shown in the book will cause a memory problem – “FATAL ERROR: JS Allocation failed – process out of memory”.

You will now need to enclose the condition within braces in the while construct and mark i++ with a hyphen.

This:

i= 0
  while i < 5
    div= i
    i++

should now be written this way:

i = 0
while (i < 5)
  div= i
  - i++