Re: Dear PHP guy

On Sat, Jul 14, 2001 at 11:43:11PM -0700, Majiko wrote: > But, unfortunately, not even the searches can help me. > I searched for a forum, but found none. An good forum to start with is phorum. U can find it on http://www.phorum.org. It GPL, so you can use it. But, there's a but; Some parts are saved to files and other parts to database, why not save it all to database.. > So, I have a simple question to ask of you... > > How do I save a class with all of it's current > variables and re-load them successfully? I mean, save > the class, goto another PHP program, re-load the > entire thing, just like in the program that saved it? > No variables changed or anything. The easiest way to save data from a class is using a database. A populair database server is MySQL. If you're planning to do a lot of writing actions or want to use transactions i advise you to use PostgreSQL. Let's save you have a class MyData: class MyData { var $name; var $message; var $dbconn; } This class is now equal to an type definition is VB. But now we're adding some functions for saving and loading from database. Because i make use a postgres database, i use the postgres functions, but most of the MySQL functions are similair. First we're going to add an constructor: function MyData($dbconn) { //dbconn is a active database connection $this->dbconn = $dbconn; return 1; } Notice the special keyword '$this->'. With this you calling the class variables internaly. function Load($name) { //we're gonna load the class with the data found in the resultset (in windows called recordset) $query = "select * from tblMessage where name='" . $name . "'"; $rsid = pg_exec($this->dbconn, $query); if (pg_numrows($rsid) > 0) { //get only the first record $rs = pg_fetch_object($rsid, 0); //fetch first row as object $this->name = $rs->name; $this->message = $rs->message; return 0; //record fetch successfull } else return 1; //no records found $pg_freeresult($rsid); //close resultset unset($rs); } And ofcourse we're want to save the data as received from a form post function Save($name) { //class data is filled with form post $query = "update tblMessage set message='" . $this->message . "' where name='" . $this->name . "'"; if (pg_cmdtuples(pg_exec($this->dbconn, $query) > 0) { //query was successfull return 0; } else { //there was an database error return 1; } } All the function must be place inside the class. the class is using an table called 'tblMessage' with columns 'name' and 'message'. On www.zend.com there are a lot of database abstraction layers. If you're farmiliar with ADO objects from MS, than maybe ADODB for php4 from http://php.weblogs.com. Here's some code to call and use the class //loading class $mc = new MyClass($cnDatabase); //$cnDatabase is an active connection with an PostgreSQL databas server $mc->load("php"); echo $mc->message . "<br>"; //saving class data $mc = new MyClass($cnDatabase); $mc->message = $HTTP_POST_VARS["message"]; $mc->save($HTTP_POST_VARS["name"]; > I suspect there is a command for it, but I cannot find > it. Otherwise, I will have to result to reading one > byte at a time, making the process much more hectic. The reason why you didn't find a saving/loading function is because you don't know HOW to save it.. You can save the data to file, database, xml or session. It's up to you to choose the right one. Don't forget that internet is stateless. You don't know what the user has done. There most sites give users cookies to track them. With the id from the cookie, that user data is loaded again from the database. All your is gone when is page is finished! Saving data to file and reading is harder, because you than have to parse the file. A good resource for php code is http://www.zend.com. Another advise: keep your first classes simple. If you now have a function with 3 or 4 argument, try to make a class of it. It's a good pratice. Later you can extend your classes or use classes within your classes. Oh, and don't try to understand it in a few hours. It's will come to you itself. Good luck, Dave Mertens