jwcolby
jwcolby at colbyconsulting.com
Sat Sep 19 21:05:41 CDT 2009
In another look at the uses of XML, many moons ago when I was trying to learn VB.Net, I wrote some stuff which used classes to store data. I am going to generalize here since I only vaguely remember what I did. Please pardon me if I use terms wrongly, and jump right in with the correct terminology. IIRC... A class can inherit the serializer interface which allows the controlling class to call a method of the data class and tell it to "serialize" itself to an XML file or to load itself from an XML file (actually a stream IIRC). This was really quite cool stuff in a way since you could enter data into a form, store the data into a class instance, enter more data into a form, store that in another class instance, storing all of these instances in a collection. Then you could write the whole thing out to a stream which ended up being an xml file on disk. Load the whole thing back out of the file on disk into the data class instances and store them in the collection. Obviously you could likewise load classes from data in a table or anywhere else you might get source data. This ended up being a quick and dirty and EASY to implement (once you learned how to do it of course) way of storing and loading data. No database file required, just XML files on disk. Now I do not want to get back into the efficiency thing, I freely admit that XML has a HUGE overhead. I am taking a course in c#. One assignment is to create a "grading program" where a form is used to enter grades. Three types of grades, each with a different weight. Enter a bunch of grades and calculate a final grade. To make it interesting and learn how to use classes and collections in C# I am taking the grades and storing them in class instances, storing the instances in a collection. This allows me to move back and forth in the entered grades, make corrections if there is a data entry error etc. A bit beyond the scope of the assignment but more interesting. So... if I make the classes serializable, I can then store them out to an XML file and read them back again. It seems the instructor knows barely more than I do about C# so it should float her boat. -- John W. Colby www.ColbyConsulting.com