Question

I have some coffeescript like the following:

class foo:
    @bar = 'bob loblaw'

    processRows: ->
        $("#my-table>tr").each ->
            id = $(this).attr("id")
            @processRow id

    processRow: (id) ->
        console.log @bar + id

So my problem is: I need this to reference the .each context inside the loop to get at id, but I also would like this to reference the class instance inside foo.processRow()—which it does not currently do.

Using something like _this = this outside the .each function and passing it around isn’t a great solution, either, since I reference many class variables inside processRow.

Any thoughts? Am I missing something obvious? Thanks!

Answer 1

jQuery.each passes the current element as second parameter of the callback, so you don’t have to reserve this for jQuery:

processRows: ->
    $("#my-table>tr").each (index, element) =>
        id = $(element).attr("id")
        @processRow id

Notice the use of the fat arrow (=>) syntax for the callback function; it binds the function’s context to the current value of this. (this in the callback function is always the same this as the one at the time you defined the function.)