TechTip: Start Using PHP on the iSeries...NOW! Part III

Web Languages
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

In Part I of this series, I showed how to install PHP on your iSeries and make sure it was functioning. In Part II, I walked though developing a simple database-listing script. Now I'm going to give you the Holy Grail of leveraging your existing code. I'll show you how to CALL your existing iSeries programs and service program functions from PHP. Well, OK, it's not actually the Holy Grail, but it's still a really good way to leverage existing code.

To start, you'll need to have the Zend Core for i5/OS installed and configured. If you don't have it already, you can download it for free. The installation instructions are also available on the Zend Web site. The next item is the Toolkit_Classes.php script, and it's installed with the Zend Core. It should be on the IFS in the /www/zendcore/htdocs/i5Toolkit_librarydirectory. You can either leave it in that directory and use a qualified Include statement (see below) or copy it into the directory where your other source code resides and use an unqualified Include statement, as I have in the sample. It should be noted that you do not have to use the Toolkit_Classes.php classes when you write your own scripts. Zend simply provides it as an example of how you can implement the base i5 functions included in the Zend Core for i5/OS product. Also, included is a demo script called “demo_for_toolkit_classes.php” that demonstrates other i5 functions. I used Toolkit_Classes.php it in our sample for the sake of simplicity.

Qualified Include:

require_once("/www/zendcore/htdocs/i5Toolkit_library/Toolkit_Classes.php");

I've created a sample script that calls a program with two parameters. The source for the sample is shown below with my descriptions, and a working version can be downloaded here.


include_once('Toolkit_classes.php');

// Functions
// Error function – display i5 call errors 
function throw_error($errDesc) {
echo "Error Description: ".$errDesc."
";

echo "Error Number: ".i5_errno()."
";

echo "Error Message: ".i5_errormsg()."
";

}

// Main script
// $USER and $PASSWORD must be a valid iSeries user profile login
$USER     = "user";
$PASSWORD = "password";

// connect to the iSeries  
try {  
$conn = new i5_Connection('127.0.0.1', $USER, $PASSWORD); Step 1 - create connection  object and connect to  the iSeries.
$conn->connect();
} catch (Exception $e) {
echo "Failure to connect";
echo $e->getMessage();
die();
}


// create parameter descriptions Step 2 – create the descriptions for the parms
$desc = new i5_Description();
$desc->I5_TYPE_PACKED('Parm1','3.0', I5_INOUT);
$desc->I5_TYPE_PACKED('Parm2', '3.0', I5_INOUT);

// create program object
$prog = new i5_Program('JEFFO','TESTAPI', $desc, $conn); Step 3 - create the program object.

// set the parameter values to pass to the program
$prog->__set('Parm1', 12 );Step 4 – load the parm values to pass into the program
$prog->__set('Parm2', 0 );

// call the program

$ret = $prog->call(); Step 5 – call the program
if (!$ret) {
    throw_error("i5_program_call");
    exit();
}

// check for errors. If no error then display the result values
if(is_null($prog->LastErr)){ Step 6 – check for errors calling the program
echo 'result Parm1:'.$prog->__get('Parm1').'
';

echo 'result Parm2:'.$prog->__get('Parm2').'
';

}
// if error found then display error details
else
{
    throw_error("Call Failed");
}
?>

This relatively simple example calls program TESTAPI in library JEFFO. The first thing you must do to prepare to run a native iSeries program is create a i5_Connection object and connect to the iSeries using a valid user profile and password. This is similar to Java code you have probably seen in the past and serves the same purpose.

try {  
$conn = new i5_Connection('127.0.0.1', $USER, $PASSWORD); Step 1 - create connection  object.
$conn->connect(); attempt to actually connect
} catch (Exception $e) { handle connection errors
echo "Failure to connect";
echo $e->getMessage();
die();
}

Next, you need to create the i5_Description object to describe the parameter values that you will be passing and receiving data in. You can think of this step as the equivalent of prototyping for a CALLP. The processing on the iSeries side of things needs to know the type, size, and usage of each parameter, and the i5_Description object is how this is accomplished. In the example above, both parameters are three-digit packed decimal with no decimal places. Below are some examples of how to define other variable types:

Always create the $desc object first:

$desc = new i5_Description();

Then, add as many parameters as you need:

// 10 Character – input/output
$desc->I5_TYPE_CHAR('Parm1','10', I5_INOUT);

// 9,4 zoned decimal  input/output
$desc->I5_TYPE_ZONED('Parm2','9.4', I5_INOUT); 

// 3,0 packed decimal  input/output
$desc->I5_TYPE_PACKED('Parm3','3.0', I5_INOUT); 

// 1 byte character input/output 
// (use for an indicator parm or return value)
$desc->I5_TYPE_CHAR('Parm4','1', I5_INOUT); 

The Toolkit_Classes.php and the Zend Core user guide have definitions for I5_TYPE_FLOAT, I5_TYPE_INT and I5_TYPE_LONG, and the support for these types will be available in an upcoming release. However, if you contact Zend support, they will send you a patch that will enable these data types in the current release. On a side note, the I5_TYPE_CHAR used with a length of one ('1'), as shown above, will function correctly for indicator-type parameters.

Once the parameter definitions are created, you're ready to create the i5_Program object. This time, you'll use both of the objects you already created: the i5_Description object and the i5_Connection object. In addition to those parameters, the i5_Program class requires the library name and program name of the program you're going to call. Yes, you can use *LIBL as the library. The library list functions just like you would hope. The list used when calling a program is by default the library list defined for the job description of the user profile that you used when you established the connection to the iSeries.

// create program object
$prog = new i5_Program('JEFFO','TESTAPI', $desc, $conn); Step 3 - create the program object.

After the i5_Program object is created, you can use the __SET method to set the values of the parameters you want to pass into the program. In the sample script, I set the values of my two numeric parameters to 12 and 0.

$prog->__set('Parm1', 12 ); Step 4 – load the parm values to pass into the program
$prog->__set('Parm2', 0 );

Now you can call the program.

// call the program
$ret = $prog->call(); Step 5 - call the program
if (!$ret) {
    throw_error("i5_program_call");
    exit();
}

The return value $ret will be false (0) if the program call fails. The values of the parameters returned after the program completes are returned in a separate structure. The i5_Program class takes care of this for you and allows you to access the returned values by using the __GET method. Take a look at the Toolkit_Classes.php if you are interested in how this actually takes place. It's an exercise that's worth the effort.

The only drawback I have come across with calling the native programs this way is in how the service program functions are supported. You can call a service program function the same way you call a program. The example below creates an i5_Program object to call the TESTFUNC procedure in the TESTAPI3 service program.

// create program object
$prog = new i5_Program('JEFFO','TESTAPI3(TESTFUNC)', $desc, $conn);

The issue is that some service functions return values. By that, I mean they use the "Return someValue;" syntax. Currently, there's no way to receive the values returned using the RETURN opcode. So that's a little limiting when you're using service programs.

There's much more functionality available regarding calling programs and commands from PHP, and I encourage you to experiment with it. The topic for Part IV (if there is to be a Part IV) has not yet been decided upon. So let me hear from you. Tell me what you'd like to know more about.

Jeff Olen is the owner of Olen Business Consulting, Inc., an iSeries development services company based in Orange, California. When he's not busy writing code or writing articles, you can find him jumping out of perfectly good airplanes (a.k.a. skydiving). To find out more about Jeff or Olen Business Consulting, Inc., go to www.olen-inc.com or email Jeff at This email address is being protected from spambots. You need JavaScript enabled to view it..

BLOG COMMENTS POWERED BY DISQUS