Subject Re: Can render problem From Charlie <trainman@traincity.com> Date Sat, 28 Nov 2015 06:53:31 -0500 Newsgroups dbase.getting-started Mervyn Bick Wrote: > On 11/28/2015 12:45 AM, Charlie wrote: > > Hi...  I used can render totaling two fields. (thanks Mervyn).. Here is the code: > > > > > >             function TEXT1_canRender() > >        this.text = this.parent.textqty1.text() * this.parent.textcost1.text() > >        return true > > > >     function TEXT2_canRender() > >        this.text = this.parent.textqty1.text() * this.parent.textsell1.text() > >        return true > > > > They work fine.  But now I am trying to total the two made up fields and don't exactly know how.  I tried the following for the first: > > > > > > function TEXT11_canRender() > >        sum this.parent.text1.text() = this.text > > SUM, as a command, is pure XDML and it also requires a TO so that it > knows where to place the result.  It is used with tables opened in > workareas and it does not work with objects at all. > > >        return true > > > > But dbase doesn't like this in that it is asking me to name the file.  Is there a way of totaling each made up field?  I don't think it is listed in the report total fields. > > > > Thanks... > > > > > When you place a text object on a report to display a field from a table > dBASE uses a codeblock to fetch the value from the record.  To be able > to access the value displayed so that you can use it in a calculation > you need to evaluate the codeblock by using the CALL operator ie a pair > of parentheses.  To display your calculated value you need to assign it > to the text property of a text object.  That is what is happening in > >     this.text = this.parent.textqty1.text() * this.parent.textcost1.text() > > > You have assigned the result from TEXTQTY1.TEXT times the value from > TEXTCOST1.TEXT to the text property of the text object. > > The thing to remember here is that you have placed actual values, not > codeblocks, in the text properties of oRef.TEXT1 and oRef.TEXT2 so, to > use these values, you don't need to use the CALL operator to access > them.  I am, however, not sure if the values are stored in the text > property as character or numeric and I can't check this for myself at > the moment.  (They should be numeric but if you get an error based on > this assumption you will need to deal with it.) > > If you want to display the sum of the two calculated values on the > detailband next to the two calculated values using oRef.TEXT11 the > following canRender event handler will do the job. > >     function TEXT11_canRender() >        this.text = this.parent.TEXT1.text + this.parent.TEXT2.text >        return true > > > I can't try this at the moment so you may need to use > > >     this.text = val(this.parent.TEXT1.text) + val(this.parent.TEXT2.text) > > > If you want to display the sum of the calculated values on a group's > footerband things get a little more complicated. > > agSum() is the "built-in" method to display totals in reports. The > problem is that agSum() method needs a codeblock as an argument. > Crafting a codeblock that will sum the value from a field is fairly > straightforward.  (An example is in the Help file.) > > Crafting a codeblock that returns agSum(fieldA)*agSum(fieldB) + > agSum(fieldC)*agSum(fieldD) should be possible but it's going to be a > MONSTER.  I don't know if there is a limit on the length of a codeblock > but this would probably be a serious contender. :-) > > So, to plan B which is DIY.  All it needs is three simple event handlers. > > As an aside.  agSUM() makes it easy to display totals of values in > fields in reports but rounding errors can creep in where the display is > to two decimal places but the values "behind the scenes" are kept to > more than two decimal places.   This problem can be dealt with if you > DIY so it is important to learn the technique which, when you think > about it, is actually very simple. > > To keep a running total as each record is rendered you need somewhere to > store the value.  Where to store running totals depends on the actual > report.  In this case a good place to store the value is in a > user-defined property of the group.  You could use a user-defined > property of the form but this would mean an extra two parents to deal > with each time.  Streamsource1 is the parent of group1 (and the > detailband) and the form is the parent of streamsource1. > > The value in the user-defined property needs to be set to zero before > you render the first detailband.   A good place to do this is in the > group's headerband onRender event handler as this is triggered before > the first detailband renders.  (The headerband's preRender event handler > would work just as well.) > >     function HEADERBAND_onRender >        this.parent.nTotal = 0 // initialise group1.nTotal >        return > > Now we need to sum the values from TEXT1 and TEXT2 to the running total. >   The actual values for TEXT1 and TEXT2 were calculated in the canRender > event handlers for the text objects > > The detailband and group1 both have streamsource1 as their parent.  Both > TEXT1 and TEXT2 are on the detailband so we use this in the detailband's > onRender event handler to save the values. > > >     function DETAILBAND_onRender >        //add the value in text1.text to the running total >        this.parent.group1.nTotal += this.text1.text >       //add the value in text2.text to the running total >        this.parent.group1.nTotal += this.text2.text >        return > > > You may need to use val(this.text1.text) and val(this.text2.text) but > try it without val() first. > > > After all the records for the group have been dealt with the group1 > footerband will render.  If TEXT11 is on the group1.footerband to > display the total you would use its canRender event handler to give it > the total to display.  The text control's parent is the footerband and > the footerband's parent is group1 > >     function TEXT11_canRender >        // fetch running total for display >        this.text = this.parent.parent.nTotal >        return true > > > > Mervyn. > Hi Mervyn, Thanks for the help.  I want to make sure I understand you. I don't want to combine the two fields qty * cost and qty * sell.  I want to to list the totals separately.  It seemed you were trying to combine them together and get a total.  Am I correct?  Is it really this complicated to do that? Charlie > > > > > > > > >