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javascriptjqueryruby-on-rails-3raty

$(this) in javascript

I'm having a problem with using this in js. I have a function that uses this like this:

var refreshRequesterStar = function() {
    $(".rating").raty({
        score: function() { return $(this).attr('data-rating'); },
        readOnly: function() { return $(this).attr('data-readonly'); },
        halfShow: true
    });
};

The rating div is as follow: 

<div class="rating" data-readonly="false" data-rating="3.0" style="cursor: default; width: 100px;" title="not rated yet">
<div class="rating" data-readonly="false" data-rating="0.0" style="cursor: default; width: 100px;" title="not rated yet">

This is called by this function: 

$("body").ajaxComplete(function(){
      refreshRequesterStar();
      $(".time_to_expire").each(function(){
            setCountDown(this);
      })
      $('select').chosen();
});

I was able to set the score value but I cannot set the readOnly value. When I debugged using firebug, I found that the first this pointed to the div but the second this pointed to window. Where I have been wrong? Note: I don't know much about JavaScript.

More info: I was using raty http://www.wbotelhos.com/raty with rails.

Solution

  • The documentation and examples indicate that the parameter score and readOnly are supposed to be numeric and boolean, not callback functions. You might want to re-write your code this:

    $(".rating").each(function() {
    // inside the function, this refers to the .rating element being iterated
    $(this).raty({
        score:    parseFloat($(this).attr('data-rating')), // see note #1
        readOnly: $(this).attr('data-readonly') == "true", // see note #2
        halfShow: true
    });
});
    1. .attr() returns a string; parseFloat() function is used to convert a string e.g. "2.5" into the number 2.5
    2. == "true" returns boolean true if the attribute value is equal to "true"; returns false in all other cases

    Ref: