it just not runs at all. Anyway, I managed to write my own function to do similar purpose. Thanks for getting back
On Sep 28, 12:55 pm, RobG <robg...@gmail.com> wrote: > On Sep 28, 1:26 pm, runrunforest <craigco...@gmail.com> wrote: > > > Hi, > > > I've got a script from dansblog (link > > herehttp://blog.pengoworks.com/index.cfm/2008/1/23/jQuery-Calculation-Plu...) > > > I copied and presented it as below, its doesn't work. What I've done > > incorrectly ? > > Most such scripts are worth what you pay for them, or less. > > > <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" > > "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";> > > <html xmlns="http://www.w3.org/1999/xhtml";> > > <head> > > <script type="text/javascript" src="js/jquery-1.3.2.min.js"></script> > > <script type="text/javascript"> > > $(function(){ > > // bind the recalc function to the quantity fields > > $("input[name^=qty_item_]").bind("keyup", recalc); > > Using the keyup event is not a good idea. You are running the listener > far more often that it needs to, you only need to run it when the user > has finished their input for a particular field (e..g. run it using > blur). > > > function recalc(){ > > // run the calc() method on each of the "total" fields > > $("[id^=total_item]").calc( > > Where is calc() defined? User input should always be validated - what > will happen if they input # instead of 3? > > > // the equation to use for the calculation > > "qty * price", > > // we now define the values for the variables > > defined in the > > Beware of those who talk about "we". > > > equation above > > { > > // instead of using a static value, we use > > a jQuery object which > > grabs all the quantities > > It grabs exactly the same set of inputs every single time the keyup > event occurs. Why would you do that except to waste CPU cycles? > > > qty: $("input[name^=qty_item_]"), > > // now we define the jQuery object which > > reads in the "price" from > > the table cell > > price: $("[id^=price_item_]") > > }, > > // this function is execute after the calculation > > is completed, > > which allows us to > > // add formatting to our value > > function (s){ > > // return the number as a dollar amount > > return "$" + s.toFixed(2); > > In some implementations, toFixed is buggy, though likely it doesn't > matter here. > > <URL:http://www.merlyn.demon.co.uk/js-rndg1.htm#toF> > > > }, > > // once all calculations are completed, we execute > > the code below > > function ($this){ > > // now we get the sum() of all the values > > we just calculated > > var sum = $this.sum(); > > Where is sum() defined? Does it validate user input? > > > > > // now that we have the grand total, we > > must update the screen > > $("#grandTotal").text( > > // round the results to 2 digits > > "$" + sum.toFixed(2) > > If the values have already been rounded, their sum does not need to be > rounded again. > > > > > ); > > } > > ); > > }}); > > > </script> > > </head> > > > <body> > > <table width="500"> > > <col style="width: 50px;" /> > > <col /> > > <col style="width: 60px;" /> > > <col style="width: 110px;" /> > > <tr> > > <th> > > Qty > > </th> > > <th align="left"> > > Product > > </th> > > <th> > > Price > > </th> > > <th> > > Total > > </th> > > </tr> > > <tr> > > <td align="center"> > > <input type="text" name="qty_item_1" id="qty_item_1" value="1" > > size="2" /> > > </td> > > <td> > > </td> > > <td align="center" id="price_item_1"> > > $39.99 > > </td> > > Somewhere there must be a calc() function that takes an input element > and gets its value, then any other type of element and gets its text > content (or value perhaps), strips off the currency sign, multiplies > the two and returns the result. Maybe it does some checking of the > values it's been passed. Or not. > > It seems strange that a function called "sum" would not do rounding. > How is invalid input handled? > > -- > Rob
