Subject Re: indexing problem From Charlie <trainman@traincity.com> Date Tue, 19 Jul 2016 19:20:28 -0400 Newsgroups dbase.getting-started Hi Mervyn... OK got it.  I didn't realize that the 'with' variable or string didn't have to be the exact same as the parameter.  Now it makes sense.  Thanks so much! Mervyn Bick Wrote: > On 18-Jul-16 11:07 PM, Charlie wrote: > > Hi Mervyn... OK I'm starting to get it thanks. > > > > I am confused though.  You have either with cindex1 or cindex2 and then the parameter is cindexname.  I don't understand that part of it.  How did it go from cindex1 or 2 to cindexname? > > > > BTW I think I was confused on what the bootstrap is. > > > > cIndex1 and cIndex2 are two variables in your XDML program.  Different > names because you have two different tags. :-) > > In point of fact you don't even need to use variables. You could simply > hard-code the tag names as literal values. >        if nForm = 1 >           DO myForm.wfm with "whatever" >        else >           DO myForm.wfm with "other" >        endif > > It's a personal preference but I seldom use literal values directly in > code.  I usually assign the values to variables or user-defined > properties of an object. > > The values after the WITH, be they literals or variables or even > properties such as form.entryfield1.value, are the "parameters" that are > passed to your OODML form. > > At the form's end of the transaction  "parameter cIndexName" does two > things.  Firstly it tells the form that it can expect a parameter and > secondly it gives a variable in which the value passed to it is to be > stored.  As only one tag can be passed at a time I used cIndexName for > the variable name as this helps me remember what is in it.  It also is > meaningful to me as I am going to assign it to the indexName property of > the form's rowset. parameter x and f.queryname.rowset.indexName = x > would have worked just as well. > > You can name variables anything you like today.  Back when I started > programming (using a VERY basic BASIC on an ICL mainframe computer) all > that was allowed were the single letters a to j.  One needed to add > copious remarks detailing what was in each variable so as not to get > things mixed up in the code. > > I still use single letters, usually n or i, for counting loops but for > the rest I've adopted the convention of starting variable names with a > lowercase letter that indicates the type of variable.  c for character, > n for numeric, d for date, b for boolean (logical), a for array and so > on.  The second letter is uppercase to improve readability.   Many > programmers use this convention as it helps to make code > "self-documenting" but it is just a convention.  You don't have to use > it if you don't want to. > > > The code for a form in OODML is a class definition based on one of the > base classes in dBASE.  It is not executable code on its own.  In other > words this is just a blueprint for a form.  As it stands it can do > nothing.  One can, however, use it to create as many identical forms as > one needs. > > To display the form dBASE needs to be told to create a form object in > memory.  This object has an open() method (and a readmodal() method) > which it has inherited from the base class which will display the form > on the screen. > > The form designer places this code, which is known as the bootstrap > code, in a form immediately before the class definition. > > parameter bModal > local f > f = new MyFormForm() > if (bModal) >        f.mdi = false // ensure not MDI >        f.readModal() > else >        f.open() > endif > > This is actual executable code which can be executed by the dBASE DO > command.  Without it you would have to load the class definition into > memory, use the NEW command to create an object from the class > definition and then open the form yourself every time you wanted to > display the form.  One can, of course, still do this.  The little > example form I posted the other day for launching a report to be saved > as an HTML page in a file with the date as the name does exactly this. > > Mervyn. > > >