synapseindia php development chaptr-2

8/10/2019 Synapseindia Php Development Chaptr-2

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Chapter 26 - PHP

Outline26.1 Introduction

26.2 PHP

26.3 String Processing and Regular Expressions

26.4 Viewing Client/Server Environment Variables

26.5 Form Processing and Business Logic

26.6 Verifying a Username and Password26.7 Connecting to a Database

26.8 Cookies

26.9 Dynamic Content in PHP

26.10 Operator Precedence

26.11 Web Resources


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Objectives

In this chapter, you will learn: To understand PHP data types, operators, arrays and

control structures.

To understand string processing and regular

expressions in PHP. To construct programs that process form data.

To be able to read and write client data using

cookies.

To construct programs that interact with MySQL

databases.


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26.1 Introduction

PHP PHP: Hypertext Preprocessor

Originally called Personal Home Page Tools

Popular server-side scripting technology

Open-source

Anyone may view, modify and redistribute source code

Supported freely by community

Platform independent


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26.2 PHP

Basic application Scripting delimiters

Must enclose all script code

Variables preceded by $symbol Case-sensitive

End statements with semicolon

Comments

//for single line

/* */for multiline

Filenames end with .phpby convention


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1< DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"

2 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

3

4 < -- Fig. 26.1: first.php -->

5 < -- Our first PHP script -->

6

7

10

11

12

13 A simple PHP document

14

15

16

17

18

19

20 < --print variable names value -->

21Welcome to PHP,

22

23

24

25

first.php

(1 of 1)

Declare variable $name

Scripting delimiters

Single-line comment

Function printoutputs the value of variable$name


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26.2 PHP

Variables Can have different types at different times

Variable names inside strings replaced by their

value

Type conversionssettypefunction

Type casting

Concatenation operator

.(period)

Combine strings


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26.2 PHP

Datatype Descriptionint, integer Wholenumbers (i.e., numbers without adecimal point).float, doubl Real numbers (i.e., numbers containingadecimal point).string Text enclosedineither single('') or double("") quotes.bool, Boolea Trueor false.array Groupof elements of thesametype.object

Groupof associateddataandmethods.Resource Anexternal datasource.NULL Novalue.

Fig. 26.2PHPdatatypes.

1


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1< DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

2"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

3

4 < -- Fig. 26.3: data.php -->

5< -- Demonstration of PHP data types -->

6

7

8

9PHP data types

10

11

12

13

14

21

data.php

(1 of 3)

Assign a string to variable$testString

Assign a double to variable$testDoubleAssign an integer to variable$testInteger

22


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22 < --print each variables value -->

23 is a string.

24 is a double.

25 is an integer.

26

27

28 Now, converting to other types:

29


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44

45 // use type casting to cast variables to a

46 // different type

47 print(Now using type casting instead:

48 As a string - . (string) $data .

49
As a double - . (double) $data .

50
As an integer - . (integer) $data );

51 ?>

52

53

data.php

(3 of 3)

Use type casting to cast variable

$datato different types


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26.2 PHPFig. 26.3 Type conversion.


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26.2 PHP

Arithmetic operators Assignment operators

Syntactical shortcuts

Before being assigned values, variables have valueundef

Constants

Named values

definefunction

1


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1 < DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

2 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

3

4 < -- Fig. 26.4: operators.php -->

5 < -- Demonstration of operators -->

6

7

8

9 Using arithmetic operators

10

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13


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25 // multiply variable $a by 2

26 $a *= 2;

27 print( "Multiplying variable a by 2 yields $a
");

28

29 // test if variable $a is less than 50

30 if( $a < 50)

31 print( "Variable a is less than 50
");

32

33 // add 40 to variable $a

34 $a += 40;

35 print( "Variable a after adding 40 is $a
");

36

37 // test if variable $a is 50 or less

38 if( $a < 51)

39 print( "Variable a is still 50 or less
");

40

41 // test if variable $a is between 50 and 100, inclusive

42 elseif( $a < 101)

43 print( "Variable a is now between 50 and 100,

44 inclusive
");

45 else

46 print( "Variable a is now greater than 100

47
");

48

operators.php

(2 of 3)

Multiply variable $aby two using the

multiplication assignment operator *=.

Test whether variable $ais less than 50

Add 40to variable $ausing the addition assignmentoperator +=.

Print if variable $ais less than 50.

49


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49// print an uninitialized variable

50 print( "Using a variable before initializing:

51 $nothing
");

52

53 // add constant VALUE to an uninitialized variable

54 $test = $num + VALUE;

55 print( "An uninitialized variable plus constant

56 VALUE yields $test
");

57

58 // add a string to an integer

59 $str = "3 dollars";

60 $a += $str;

61 print( "Adding a string to variable a yields $a

62
");

63 ?>

64

65

operators.php

(3 of 3)

Add constant VALUEto an uninitialized

variable.

Add a string to an integer.

Print an uninitialized variable ($nothing).


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26.2 PHPFig. 26.4 Using PHPs arithmetic operators.


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26.2 PHP

Keywords Reserved for language features

ifelseifelse

Arrays

Group of related data

Elements

Name plus braces and index

Indices start at zero

countfunction

arrayfunction


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26.2 PHP

Arrays, cont. Built-in iterators

Maintain pointer to element currently referenced

reset

key

next

foreachloops


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26.2 PHP

PHPkeywords andbreakcaseclasscontinuedefault

doelseelseifextendfalse

forforeachfunctioglobalif

includlistnewnotor

requirreturnstaticswitchthis

truevarvirtualxorwhile

Fig. 26.5PHPkeywords.



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3

4< -- Fig. 26.6: arrays.php -->

5< -- Array manipulation -->

6

7

8

9Array manipulation

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26.2 PHPFig. 26.6 Array manipulation.


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26.3 String Processing and Regular

Expressions

String processing Equality and comparison two important operations

strcmpfunction

Returns1 if string 1 < string 2

Returns 0 if string 1 = string 2 Returns 1 if string 1 > string 2

Relational operators



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3

4 < -- Fig. 26.7: compare.php -->

5 < -- String Comparison -->

6

7

8

9 String Comparison

10

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13


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26 print( $fruits[ $i ].

27 " is greater than banana ");

28 else

29 print( $fruits[ $i ]." is equal to banana ");

30

31 // use relational operators to compare each element

32 // to string "apple"

33 if( $fruits[ $i ] < "apple")

34 print( "and less than apple
");

35 elseif( $fruits[ $i ] > "apple")

36 print( "and greater than apple
");

37 elseif( $fruits[ $i ] == "apple")

38print( "and equal to apple
");

39

40 }

41 ?>

42

43

compare.php

(2 of 2)

Use relational operators to compare each arrayelement to string apple.

26 3 St i P i d R l


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ExpressionsFig. 26.7 Using the string comparison operators.

26 3 St i P i d R l


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Expressions

Regular expressions Pattern matching templates

eregfunction

POSIX

preg_matchfunction Perl

ereg_replacefunction

Building regular expressions

Metacharacters

$, ., ^

Brackets [ ]



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2"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

3

4 < -- Fig. 26.8: expression.php -->

5< -- Using regular expressions -->

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7

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9Regular expressions

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13


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23 // the string

24 if( ereg( "^Now", $search ) )

25 print( "String 'Now' found at beginning

26 of the line.
");

27

28 // search for pattern 'Now' at the end of the string

29 if( ereg( "Now$", $search ) )

30 print( "String 'Now' was found at the end

31 of the line.
");

32

33 // search for any word ending in 'ow'

34 if( ereg( "[[::]]", $search,

35$match ) )

36 print( "Word found ending in 'ow': ".

37 $match[ 1] . "
");

38

39 // search for any words beginning with 't'

40 print( "Words beginning with 't' found: ");

41

42 while( eregi( "[[::]]",

43 $search, $match ) ) {

44 print( $match[ 1] . " ");

45

expression.php

(2 of 3)

The dollar sign special character ($) search for the

pattern Nowat the end of the string.

The expression inside the parentheses, [a-zA-Z]*ow,

matches any word ending in ow. The quantifier *

matches the preceding pattern 0or more times.

The special bracket expressions [[::]]match the beginning and end of a

word, respectively.

Placing a pattern in parentheses stores the matched

string in the array that is specified in the third argument

to function ereg.

The whileloop is used to find each occurrence of a

word in the string beginning with t.

The pattern used in this example,

[[::]], matches any

word beginning with the character tfollowed by one or

more characters. Character class [[:alpha:]]

recognizes any alphabetic character.

Function eregiis used to specify case insensitive

pattern matches.

The caret special character (^) matches the

beginning of a string. Function eregsearches the

beginning of the string for pattern Now.


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26 3 St i P i d R l


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ExpressionsFig. 26.8 Regular expressions in PHP.

26 3 St i P i d R l


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Expressions

Quantifier Matches{n} Exactlyntimes.{m,n} Betweenmandntimes inclusive.{n,} nor moretimes.+ Oneor moretimes (sameas{1,}).

* Zeroor moretimes (sameas{0,}).? Zeroor onetime(sameas{0,1}).

Fig. 26.9 SomePHPquantifiers.

26 3 St i P i d R l


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Expressions

Character class Descriptionalnum Alphanumericcharacters(i.e., letters[a-zA-Z] or digits[0-9]).alpha Wordcharacters(i.e., letters[a-zA-Z]).digit Digits.space Whitespace.

lower Lowercaseletters.upper Uppercaseletters.

Fig. 26.10 SomePHPcharacter classes.

26 4 Vie ing Client/Ser er


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26.4 Viewing Client/Server

Environment Variables

Environment variables Provide information about execution environment

Type of Web browser

Type of server

Details of HTTP connection Stored as array in PHP

$_ENV

26 4 Viewing Client/Server


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Environment Variables

Variablename Description

$_SERVER Dataabout thecurrentlyrunningserver.$_ENV Dataabout theclientsenvironment.$_GET Datapostedtotheserver bythegetmethod.$_POST Datapostedtotheserver bythepostmethod.$_COOKIE Datacontainedincookiesontheclientscomputer.$GLOBALS Arraycontainingall global variables.

Fig. 26.11 Someuseful global arrays.


2


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3

4 < -- Fig. 26.11: env.php -->

5 < -- Program to display environment variables -->

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7

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9 Environment Variables

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15

24

25

26

env.php

(1 of 1)

The foreachloop is used to print out the keys andvalues for each element in the $_ENVarray.PHP stores environment variables and their values in

the $_ENVarray.

26 4 Viewing Client/Server


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Environment VariablesFig. 26.12 Displaying environment variables.

26 5 Form Processing and Business


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26.5 Form Processing and Business

Logic

Form processingactionproperty

Where to send form data

methodproperty

post Each element has unique name


2


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3

4 < -- Fig. 26.13: form.html -->

5 < -- Form for use with the form.php program -->

6

7

8

9 Sample form to take user input in XHTML

10

11

12

13

14This is a sample registration form.

15 Please fill in all fields and click Register.

16

17 < -- post form data to form.php -->

18

19

20

21Please fill out the fields below.

22

23

form.html

(1 of 4)

The actionattribute of the formelement

indicates that when the user clicks Register, theform data will be posted to form.php.

24 < -- create four text boxes for user input -->

25

A i ( il) i i d t h


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25

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38 Must be in the form (555)555-5555

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44

45 Which book would you like information about?

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47

form.html

(2 of 4)

A unique name(e.g., email) is assigned to each

of the forms inputfields. When Registeris

clicked, each fields nameand valueare sent to

the Web server.

48 < -- create drop-down list containing book names -->

49


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49

50 Internet and WWW How to Program 3e

51 C++ How to Program 4e

52 Java How to Program 5e

53 XML How to Program 1e

54

55

56

57

58

59 Which operating system are you currently using?

60

61

62 < -- create five radio buttons -->

63

65 Windows XP

66

67

69 Windows 2000

70

71

73 Windows 98

form.html

(3 of 4)

74

75


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form.html

(4 of 4)

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76 Linux

77

78

79 Other

80

81 < -- create a submit button -->

82

83

84

85

86



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LogicFig. 26.13 XHTML form for gathering user input.



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Logic

Business logic Confirm that valid information was entered

extractfunction

Creates variables corresponding to each key-value pair

in array Easily retrieve all values sent to PHP page

Regular expressions very helpful

Do checks on client side where possible

JavaScript Conserves server resources

Ending a script

diefunction

Remember to close all HTML tags




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3

4< -- Fig. 26.14: form.php -->

5< -- Read information sent from form.html -->

6

7

8

9 Form Validation

10

11

12

13

14


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24 INVALID PHONE NUMBER

25 A valid phone number must be in the form

26 (555)555-5555

27

28 Click the Back button, enter a valid phone

29 number and resubmit.

30 Thank You.
");
31

32 die(); // terminate script execution

33 }

34 ?>

35

36

Hi

37

38

39

40

41 .

42Thank you for completing the survey.

43

form.php

(2 of 4)

Function dieterminates script execution


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66 print each form fields value

67 print("$fname $lname


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form.php

(4 of 4)

68 $email

69 $phone

70 $os");

71 ?>

72

73

74

75

76

77 This is only a sample form.

78 You have not been added to a mailing list.

79

80

81



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LogicFig. 26.14 Obtaining user input through forms.

26 6 Verifying a Username and


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26.6 Verifying a Username and

Password

Private website

Only accessible to certain individuals

Encrypt username and password data when sending,

storing and retrieving for increased security

Implementing password checking Login information stored in file

fopenfunction

Read, write, append modes

Store data using fputs

\nnewline character

Close files when done

fclosefunction

26 6 Verifying a Username and


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Password

Implementing password checking, cont.

Trim newline character

chopfunction

Split string into substrings given a certain delimiter

splitfunction If username/password match list, allow access




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3

4 < -- Fig. 26.15: password.html -->

5 < -- XHTML form sent to password.php for verification -->

6

7

8

9 Verifying a username and a password.

10

11

12 td { background-color: #DDDDDD }

13

14

15

16

17

18 Type in your username and password below.

19

20

22 Note that password will be sent as plain text

23

24

25

password.html

(1 of 4)

26 < -- post form data to password.php -->

27


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28

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33

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36 Username:

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45

46

password.html

(2 of 4)

Form data is posted to password.php.

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48


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49Password:

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67

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71

password.html

(3 of 4)

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73


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76 password.html

(4 of 4)



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PasswordFig. 26.15 XHTML form for obtaining a username and password.




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3

4 < -- Fig. 26.16: password.php -->

5 < -- Searching a database for usernames and passwords. -->

6

7

8

9


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27print( "Error

28 Could not open password file

29 ");

30die();

31}

32

33// write username and password to file and

34// call function userAdded

35 fputs( $file, "$USERNAME,$PASSWORD\n");

36 userAdded( $USERNAME );

37 }

38 else{

39

40// if a new user is not being added, open file

41// for reading

42if( ( $file = fopen( "password.txt",

43"r") ) ) {

44 print( "Error

45Could not open password file

46");

47 die();

48 }

49

password.php

(2 of 7)Print an error message and terminate script execution

if the file cannot be opened.

Function fputswrites the name and password to thetext file..

Function userAddedis called to print a message to the

user to indicate that the username and password wereadded to the file.

50$userVerified = 0;

51


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52 // read each line in file and check username

53 // and password

54 while ( feof( $file ) && $userVerified ) {

55

56// read line from file

57$line = fgets( $file, 255);

58

59 // remove newline character from end of line

60 $line = chop( $line );

61

62 // split username and password

63 $field = split( ",", $line, 2);

64

65// verify username

66if( $USERNAME == $field[ 0] ) {

67$userVerified = 1;

68

69// call function checkPassword to verify

70users password

71if( checkPassword( $PASSWORD, $field )

72== true)

73 accessGranted( $USERNAME );

74 else

75 wrongPassword();

password.php

(3 of 7)

Before entering the whileloop, variable

$userVerifiedis set to 0.

The whileloop executes as long as the there are morelines in the file to read and variable $userVerifiedis

still 0or empty.

Function fgetsreads a line from the text file.

The result is assigned to variable $line.

Function chopremoves the newline characterfrom the end of the line.

Function splitis called to separate the string at the

specified delimiter (in this case, a comma). The

resulting array is stored in array $field.The username entered by the user is tested

against the one returned in the text file (stored

in the first element of the array). If they match,

variable $userVerifiedis set to 1.

Function checkPasswordis called to verify the

users password. Variable $PASSWORDand array

$fieldare passed to the function.

If function checkPasswordreturns true, function

accessGrantedis called to notify the client thatpermission has been granted. Otherwise, function

wrongPasswordis called.

76 }

77 }

78

If variable $userVerified has not been set to a


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78

79 // close text file

80 fclose( $file );

81

82// call function accessDenied if username has

83 // not been verified

84 if( $userVerified )

85accessDenied();

86 }

87

88 // verify user password and return a boolean

89 functioncheckPassword( $userpassword, $filedata )

90{

91 if( $userpassword == $filedata[ 1] )

92returntrue;

93 else

94 returnfalse;

95 }

96

password.php

(4 of 7)

After the whileloop has executed, function

fcloseis called to close the file.

If variable $userVerifiedhas not been set to a

value other than 0, function accessDeniedis

called to notify the client that access has been

denied.

Function checkPasswordcompares the users

password to the password in the file. If they match,

trueis returned, whereas falseis returned if they

do not.

97 // print a message indicating the user has been added

98 functionuserAdded( $name )

99


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99 {

100 print( "Thank You

101

103 You have been added

104 to the user list, $name.

105
Enjoy the site.");

106 }

107

108 // print a message indicating permission

109 // has been granted

110 functionaccessGranted( $name )

111 {

112 print( "Thank You

113

115 Permission has been

116 granted, $name.

117 Enjoy the site.");

118 }

119

password.php

(5 of 7)Function userAddedprints a message to the

client indicating that the user has been added.

Function accessGrantedprints amessage to the client indicating that

permission has been granted.

120// print a message indicating password is invalid

121 functionwrongPassword()

122


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122 {

123print( "Access Denied

124

126 You entered an invalid

127password.
Access has

128 been denied.");

129 }

130

131 // print a message indicating access has been denied

132 functionaccessDenied()

133 {

134print( "Access Denied

135

137

138 You were denied access to this server.

139
" );

140}

141

password.php

(6 of 7)

Function wrongPasswordprints a message to the

client indicating that the password is invalid.

Function accessDeniedprints a message to the

client indicating that access has been denied.

142// print a message indicating that fields

143// have been left blank

144

Function fieldsBlankprints a message to the


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144 functionfieldsBlank()

145{

146 print("Access Denied

147

149

150 Please fill in all form fields.

151
");

152 }

153 ?>

154

155

password.php

(7 of 7)

client indicating that all form fields have not been

completed.



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y g

PasswordFig. 26.16 Verifying a username and password.

1account1,password12account2,password2

3


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password.txt

(1 of 1)

3account3,password3

4account4,password4

5account5,password5

6account6,password6

7account7,password7

8account8,password8

9account9,password9

10account10,password10

26 7 Connecting to a Database


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26.7 Connecting to a Database

Databases

Store and maintain data

MySQL is a free database product

PHP supports many database operations

Access databases from Web pages


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23 *

24


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24 ID

25 Title

26 Category

27 ISBN

28

29

30

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34

35

36

data.html

(2 of 2)

Select box containing options for a SELECT

query.



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Fig. 26.18 Form to query a MySQL database.



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Interacting with databases

SQL

Structured Query Language

Used to manipulate databases

Several useful functionsmysql_connect

mysql_select_db

mysql_query

mysql_error

mysql_fetch_rowmysql_close



3


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3

4< -- Fig. 26.19: database.php -->

5 < -- Program to query a database and -->

6< -- send results to the client. -->

7

8

9

10Search Results

11

12

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15


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29 die( "Could not open Products database");

30

31 // query Products database

32 if( ( $result = mysql_query( $query, $database ) ) ) {

33print( "Could not execute query
");

34 die( mysql_error() );

35 }

36?>

37

38

39 Search Results

40

41

43

44


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54 foreach( $row as$key => $value )

55 print( "$value");

56

57 print( "");

58}

59

60mysql_close( $database );

61 ?>

62

63

64

65
Your search yielded

66 results.

67

68 Please email comments to

69

70 Deitel and Associates, Inc.

71

72

73

74

75

database.php

(3 of 3)

The foreachloop iterates through the

array containing the elements of each rowand prints out each element in an

individual table cell.The total number of results are printed to the

client.



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Fig. 26.19 Querying a database and displaying the results.

26 8 Cookies


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26.8 Cookies

Cookies

Store information on client computer

Track preferences and other information

Stored as text files on hard drive

Never store sensitive information, such as creditcard numbers, in a cookie

Security risk

Cookies and PHP

setcookiefunction

Name

Value

Expiration date

1< DOCTYPE html PUBLIC"-//W3C//DTD XHTML 1.0 Transitional//EN"


3


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4 < -- Fig. 26.20: cookies.html -->

5 < -- Writing a Cookie -->

6

7

8

9 Writing a cookie to the client computer

10

11

12

14

15 Click Write Cookie to save your cookie data.

16

cookies.html

(1 of 2)

17

19 Name:
Form data is posted to cookies.php.


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20

21

22 Height:

23

24

25 Favorite Color:

26

27

28

31

32

33

cookies.html

(2 of 2)

p p p

26 8 Cookies


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26.8 Cookies

Fig. 26.20 Gathering data to be written as a cookie.

1


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4

5 extract( $_POST );

6 write each form fields value to a cookie and set the

7 cookies expiration date

8 setcookie( "Name", $NAME, time() + 60* 60* 24* 5);

9 setcookie( "Height", $HEIGHT, time() + 60* 60* 24* 5);

10 setcookie( "Color", $COLOR, time() + 60* 60* 24* 5);

11 ?>

12



15

16

17

18 Cookie Saved

19

20

21

22

The cookie has been set with the following data:

23

cookies.php

(1 of 2)

Function setcookietakes the name of the

cookie to be set as the first argument,

followed by the value to be stored in the

cookie. The optional third argument specifies

the expiration date of the cookie.

24 < --print each form fields value-->

25
Name:

26

Each form fields valueis printed to

confirm the data that has been set as a


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82

27

28 Height:

29

30

31 Favorite Color:

32

33


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83

26.8 Cookies

Fig. 26.21 Writing a cookie to the client.

26 8 Cookies


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84

26.8 Cookies

Reading cookies

$_COOKIEenvironment variable

Array

foreachloop to access each element

Split into key and value

26 8 Cookies


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85

26.8 Cookies

Cookie storage

Internet Explorer

Stores cookies in Cookiesdirectory

Text file

26 8 Cookies


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26.8 Cookies

Fig. 26.22 Cookiesdirectory before a cookie is written.

Fig. 26.23 Cookiesdirectory after a cookie is written.



3


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4 < -- Fig. 26.24: readCookies.php -->

5 < -- Program to read cookies from the client's computer -->

6

7

8Read Cookies

9

10

11

12

13

14 The following data is saved in a cookie on your

15 computer.

16

17

18

readCookies.php

(1 of 2)


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26.8 Cookies


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89

26.8 Cookies

Fig. 26.24 Displaying the cookies content.



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Dynamically alter XHTML content

Forms actionproperty set to same page that

contains it

Perform different actions when page is loaded and

form is submitted

issetvariable

Check for errors

Write different XHTML when errors encountered

$$variablesyntax References variable whose name equals the value of

$variable

If input is valid, make MySQL database calls

1 < DOCTYPE html PUBLIC"-//W3C//DTD XHTML 1.0 Transitional//EN"


3

4


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91

4 < -- Fig. 26.25: dynamicForm.php -->

5 < -- Form for use with the form.php program -->

6

7

8

9 Sample form to take user input in XHTML

10

11

12

13


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92

26 "Windows 98",

27 "Linux",

28 "Other");

29

30 // array of name and alt values for the text input fields

31 $inputlist = array( "fname"=> "First Name",

32 "lname"=> "Last Name",

33 "email"=> "Email",

34 "phone"=> "Phone");

35

36 if( isset ( $submit ) ) {

37 if( $fname == "") {

38 $formerrors[ "fnameerror"] = true;

39 $iserror = true;

40 }

41

42 if( $lname == "") {

43 $formerrors[ "lnameerror"] = true;

44 $iserror = true;

45 }

46

dynamicForm.php

(2 of 9)

Check for errors or omissions in form field

input.

If the page is being loaded as a result of a form

submission, do error checking and then retrieve

information from the database.

47 if( $email == "") {

48 $formerrors[ "emailerror"] = true;

49 $iserror = true;

50


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50 }

51

52if( ereg( "^$[0-9]{3}$[0-9]{3}-[0-9]{4}$", $phone ) ) {

53$formerrors[ "phoneerror"] = true;

54$iserror = true;

55 }

56

57 if( $iserror ) {

58

59 // build INSERT query

60 $query = "INSERT INTO contacts ".

61"( LastName, FirstName, Email, Phone, Book, OS ) ".

62"VALUES ( '$lname', '$fname', '$email', ".

63"'". quotemeta( $phone ) . "', '$book', '$os' )";

64

65// Connect to MySQL

66if( ( $database = mysql_connect( "localhost",

67"httpd", "") ) )

68die( "Could not connect to database" );

69

70 // open MailingList database

71 if( mysql_select_db( "MailingList", $database ) )

72 die( "Could not open MailingList database");

dynamicForm.php

(3 of 9)

If there were no errors, query the MySQL

database.

73

74// execute query in MailingList database

75if( ( $result = mysql_query( $query, $database ) ) ) {

76


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94

");

77die( mysql_error() );

78 }

79

80print( "

Hi

81

82$fname.

83Thank you for completing the survey.

84

85You have been added to the

86

87$book

88mailing list.

89

90The following information has been saved

91in our database:

92

93

94

95Name

96Email

97Phone

dynamicForm.php

(4 of 9)

98OS

99

100

101


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95

101

102 < --print each form fields value -->

103$fname $lname

104$email

105$phone

106$os

107

108

109

110

111

112

113Click here to view entire database.

114This is only a sample form.

115You have not been added to a mailing list.

116");

117 die();

118}

119}

120

121 print( "This is a sample registration form.

122Please fill in all fields and click Register.");

dynamicForm.php

(5 of 9)

Halt the script so the form-generation code

does not execute.

123

124 if( $iserror ) {

125 print( "

126


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126 Fields with * need to be filled in properly.");

127 }

128

129print( "< -- post form data to form.php -->

130

131

132

133 Please fill out the fields below.

134

135

136 < -- create four text boxes for user input -->");

137foreach( $inputlist as$inputname => $inputalt ) {

138$inputtext = $inputvalues[ $inputname ];

139

140print( "");

143

144if( $formerrors[ ( $inputname )."error"] == true)

145print( "*");

146

147 print( "
");

148 }

dynamicForm.php

(6 of 9)

If the form input contained errors, place a red

asterisk (*) next to the text field.

Fill in the forms using$$variable

syntax.

149

150print( "


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97

152if( $formerrors[ "phoneerror"] )

153print( "; color : red");

154

155 print( "'>Must be in the form (555)555-5555

156

157

158

160

161

162Which book would you like information about?

163

164

165< -- create drop-down list containing book names -->

166");

167

168foreach( $booklist as$currbook ) {

169print( "$currbook");

175 }

176

177


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98

177 print( "

178

179

180Which operating system are you currently using?

181

182

183 < -- create five radio buttons -->");

184

185 $counter = 0;

186

187 foreach( $systemlist as$currsystem ) {

188print( "$currsystem");

195

196if( $counter == 2) print( "
");

197 $counter++;

198 }

199

dynamicForm.php

(8 of 9)

Make sure the correct OS is checked in thecheckbox.

200 print("< -- create a submit button -->

201

202

203


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203 ");

204 ?> dynamicForm.php

(9 of 9)



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100

y

Fig. 26.25 Dynamic form using PHP.



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y

Fig. 26.25 Dynamic form using PHP.

1< DOCTYPE html PUBLIC"-//W3C//DTD XHTML 1.0 Transitional//EN"


3

4


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102

4< -- Fig. 26.26: formDatabase.php -->

5< -- Program to query a database and -->

6< -- send results to the client. -->

7

8

9

10Search Results

11

12

13

15


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30

31// query MailingList database

32if( ( $result = mysql_query( $query, $database ) ) ) {

");

34die( mysql_error() );

35}

36 ?>

37

38

39 Mailing List Contacts

40

41

43

44

45 ID

46Last Name

47First Name

48 E-mail Address

49 Phone Number

50Book

formDatabase.php

(2 of 3)

51Operating System

52

53


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104

55 // fetch each record in result set

56for( $counter = 0;

57$row = mysql_fetch_row( $result );

58$counter++ ){

59

60 // build table to display results

61 print( "");

62

63 foreach( $row as$key => $value )

64 print( "$value");

65

66print( "");

67 }

68

69mysql_close( $database );

70 ?>

71

72

73

74

75

formDatabase.php

(3 of 3)

Dynamically create a table

containing each mailing list

member.

member record from the

database.



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Fig. 26.26 Displaying the MailingListdatabase.



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Operator Type Associativitynew constructor none

[] subscript right to left

~!++---@

bitwise notnot

increment

decrement

unary negative

error control

right to left

*/%

multiplication

division

modulus

left to right

+-.

addition

subtraction

concatenation

left to right

>

bitwise shift left

bitwise shift right

left to right

=

less than

greater than

less than or equal

greater than or equal

none

==!====!==

equal

not equal

identical

not identical

none

Fig. 26.27 PHP operator precedence and associativity.



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Operator Type Associativity& bitwise AND left to right

^ bitwise XOR left to right

| bitwise OR left to right&& logical AND left to right

|| logical OR left to right

=+=-=*=/=

&=|=^=.==

assignment

addition assignment

subtraction assignment

multiplication assignment

division assignment

bitwise AND assignment

bitwise OR assignment

bitwise exclusive OR assignment

concatenation assignment

bitwise shift left assignment

bitwise shift right assignment

left to right

and logical AND left to right

xor exclusive OR left to rightor logical OR left to right

, list left to right

Fig. 26.27 PHP operator precedence and associativity.

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