Question

I’m having problems with one of my anchors when clicked, it throws TypeError: obj is null on a single item. All others work perfectly, there are no differences in the objects that are being passed. In a list of 4 of the same items, there is only one that errors. All console.logs show no data that isn’t set. I’ve come to a part where I’m just utterly stuck with debugging.

    $('.admin-user-list-click').live('click', function(evt) {
        evt.preventDefault();
        var user_id = $(this).attr('user_id');
        var screen_id = $(this).attr('screen_id');
        var href = $(this).attr('href');
        var last_updated = $(this).attr('updated');
        var last_login = $(this).attr('last_login');
        var user_data = [];
        var template_structure = {logged_in: 'last_login', last_updated: 'last_updated', user_data: user_data, screen_id: screen_id, screen_data: [], identifier: 'screen'};
        var displayContainer = $(this).closest('.admin-page').find('.admin-display');
        $.ajax({
            url: href + '/index/'+user_id,
            success: function(data){
                //Basic user information
                var result = $.parseJSON(data);
                $.each(result, function(k, v) {
                    user_data.push({identifier: k, data: v});
                });
                $.ajax({
                    url: href + '/get_user_data/'+user_id,
                    success: function(data){
                        //Question and answers from registeration
                        var decode = $.parseJSON(data);
                        template_structure.screen_data = decode;
                        console.log(displayContainer)
                        console.log(pending_template)
                        console.log(template_structure)
                        console.log(pending_template(template_structure))
                        displayContainer.html(pending_template(template_structure));
                    }
                })

            }// closure of success
        })

}); //closure of click event

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Output of console.log(displayContainer) [div.admin-display]

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Output of console.log(pending_template) function()

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Output of console.log(template_structure) Object { logged_in= "2012-10-26 08:40:16", user_data=[14], screen_id= "0001", more...}

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Output of console.log(pending_template(template_structure)) shows nothing

The line in question is on 583 in jquery.1.8.2

// args is for internal usage only
each: function( obj, callback, args ) {
    var name,
        i = 0,
        length = obj.length, //this is the line that errors

---

When console.log(obj) it shows
When errored

When it works

Answer 1

Problem was due to the handlebar helper I had created

Handlebars.registerHelper('json_check', function(answer, answer_type) {
    if(answer_type == 'json' && answer !== ''){
        text = '';
        var response = $.parseJSON(answer);
        $.each(response, function(key, value) {
            text += "<p>"+key+"</p><p>"+value+"</p>";
        });
        return new Handlebars.SafeString(text);
    } else {
        return answer;
    }
});

The problem was that at first I wasn’t checking if answer was an empty string. So trying to parseJson an empty string threw the error.