PHP Script Writing Essentials: Arrays, Emails, and Logic

CIT 3353 -- Fall 2006 www.clt.astate.edu/jseydel/mis3353 Website Development & Management More PHP Odds & Ends Instructor: John Seydel, Ph.D.

Student Objectives Upon completion of this class meeting, you should be able to: • Create an onLoad event handler for a web page • Use the foreach() construct to loop through an array of data • Use ereg() to validate email addresses • Use switch() in place of the if()/elseif() construct • Discuss how data are stored and processed using arrays

Some Other Things (continued) • Note some things in the FKAuto calculator page (calc.php) • JavaScript • Arrays • foreach() construct • Review and enhancement of email handling • Replace if() construct with switch() construct • Check for a valid email address • Use ereg() • Case-sensitive; use eregi() for case-insensitive • Alternative to preg_match(), which is a Perl-compatible function • Search for an “at” symbol (@) • Syntax: ereg(”@”,$strTo) • Add onLoad event handler to <body> • Review and revision of the script writing process

What We’ve Looked at Today • Using JavaScript to create an onLoad event handler • How for() and foreach() constructs work • The ereg() function • Comparison of switch() and if()/elseif() • Array concepts

Appendix

Arrays • Creating a simple array $arrTerm = array(2,3,4,5,6,7); or $arrTerm = range(2,7); • This is an indexed array • For element $arrTerm[0] • Index is 0 • Value is 2 • For element $arrTerm[5] • Index is 5 • Value is 7 • To add an element: $arrTerm[6] = 8; or array_push($arrTerm,8); • The number of array elements is count($arrTerm)

Associative Arrays • Creating an associative array $arrCustomer[‘Person’]= “Jenny”; $arrCustomer[‘Phone’]= “867-5309”; or $arrCustomer = array(“Person”=>”Jenny”,”Phone”=>”867-5309”); • Array contents • For element $arrCustomer[’Person’] • Name is Person • Value is Jenny • For element $arrCustomer[’Phone’] • Name is Phone • Value is 867-5307 • Some typical associative arrays • Form data, e.g., $_POST[‘txtCustomer’] and other elements • Database recordset rows; e.g., $strResult[‘Model’] and other

Review: Sending eMail • Makes use of the mail() function • String Arguments accepted: • Recipient • Subject • Message • Header • From (overrides value specified in php.ini) • Reply-to • Other . . . • Consider a one-line example (poor coding)

Process Guidelines for Writing Scripts: Original Recommendation • Start by initializing • Assign initial values to variables • Define constants if any • Get data • From form • From other sources • Prepare data for processing • Write the processing logic • Branching as appropriate • Calculations as appropriate • String manipulations as appropriate • Other processing (e.g., send mail, write to database, . . . ) • Format results for output as appropriate

Revised Script Writing Process • Prior to the XML/HTML • Initialization • Get data • From forms and other sources (but not databases) • Validate as appropriate • After <html . . . > and before <head> • Prepare data for processing • Get data from database • Write the processing logic • Branching, calculations, and string manipulations as appropriate • Other processing (e.g., send mail, write to database, . . . ) • Other database queries • Format results for output as appropriate • Within <head> and <body>, limit PHP to scriptlets that display pre-generated HTML output blocks

PHP Script Writing Essentials: Arrays, Emails, and Logic