jquery计算获取计算的大小答案

【问题标题】：jquery calculation getting size of calculationsjquery计算获取计算的大小
【发布时间】：2011-04-09 04:21:30
【问题描述】：

我使用 Jquery 计算插件成功地对小计和总计执行了两次计算，就像演示页面上的最后一个示例一样：

http://www.pengoworks.com/workshop/jquery/calculation/calculation.plugin.htm

但是，我还想获得所选床位的总数，但似乎不知道如何添加它，有什么想法吗？

    function recalc(){
        //$("[id^=total_item]").calc(
        $("div[id^=subtotal_]").calc(
            // the equation to use for the calculation
            "qty * price",
            // define the variables used in the equation, these can be a jQuery object
            {
                qty: $("select[id^=room_]"),
                price: $("div[id^=price_]")
            },
            // define the formatting callback, the results of the calculation are passed to this function
            function (s){
                // return the number as a dollar amount
                return "<%=session[:symbol]%>" + s.toFixed(2);
            },
            // define the finish callback, this runs after the calculation has been complete
            function ($this){
                // sum the total of the $("[id^=total_item]") selector
                var count = $this.size(); <--- doesn't give me a correct count
                var sum = $this.sum();


                $("#totals").text(
                    // round the results to 2 digits
                    "You have selected " + count + " rooms for a total of <%=session[:symbol]%>" + sum.toFixed(2)
                );
            }
        );
    }

【问题讨论】：

它有什么不妥之处？太高，太低，选择不应该的？
它总是返回 4。;-) 所以我显然不明白发生了什么重要的事情。
总和返回完美......这是所有小计的总和。

标签： javascript jquery jquery-plugins jquery-calculation

【解决方案1】：

没关系，这似乎有效：

    $(document).ready(
        function (){
            $("select[id^=room_]").bind("change", recalc);
        }
    );

    function recalc(){
        //$("[id^=total_item]").calc(
        var counter = $("select[id^=room_]").sum();
        $("div[id^=subtotal_]").calc(
            // the equation to use for the calculation
            "qty * price",
            // define the variables used in the equation, these can be a jQuery object
            {
                qty: $("select[id^=room_]"),
                price: $("div[id^=price_]")
            },
            // define the formatting callback, the results of the calculation are passed to this function
            function (s){
                // return the number as a dollar amount
                return "<%=session[:symbol]%> " + s.toFixed(2);
            },
            // define the finish callback, this runs after the calculation has been complete
            function ($this){
                // sum the total of the $("[id^=total_item]") selector
                var count = $this.size();
                var sum = $this.sum();

                if (sum > 0) { $("#totals").fadeIn(); } else { $("#totals").fadeOut(); }

                $("#totals").text(
                    // round the results to 2 digits
                    "You have selected " + counter + " beds for <%= user_cart.getDays %> nights totaling <%=session[:symbol]%> " + (sum * <%= user_cart.getDays.to_i %>).toFixed(2)
                );
            }
        );
    }

【讨论】：