L ISTING 27.5 store_account_settings Function from mail_fns.php—Function to SaveNew Account Details for a User function store_account_settings$auth_user, $settings { if!filled_out$settin
Trang 1L ISTING 27.5 store_account_settings() Function from mail_fns.php—Function to Save
New Account Details for a User
function store_account_settings($auth_user, $settings)
{
if(!filled_out($settings))
{
echo “All fields must be filled in Try again.<br><br>”;
return false;
}
else
{
if($settings[‘account’]>0)
$query = “update accounts set server = ‘$settings[server]’,
port = $settings[port], type = ‘$settings[type]’, remoteuser = ‘$settings[remoteuser]’,
remotepassword = ‘$settings[remotepassword]’
where accountid = $settings[account]
and username = ‘$auth_user’”;
else
$query = “insert into accounts values (‘$auth_user’,
‘$settings[server]’, $settings[port],
‘$settings[type]’, ‘$settings[remoteuser]’,
‘$settings[remotepassword]’, NULL)”;
if(db_connect() && mysql_query($query)) {
return true;
} else { echo “could not store changes.<br><br><br><br><br><br>”;
return false;
} }
}
As you can see, two choices within this function correspond to inserting a new account or
updating an existing account The function executes the appropriate query to save the account
details
After storing the account details, we go back to index.php, to the main body stage:
case ‘store-settings’ :
case ‘account-setup’ :
case ‘delete-account’ :
{
display_account_setup($auth_user);
break;
}
27
Trang 2As you can see, we then execute the display_account_setup() function as before to list the user’s account details The newly added account will now be included
Modifying an Existing Account
The process for modifying an existing account is very similar The user can change the account details and click the Save Changes button Again this will trigger the store-settingsaction, but this time it will update the account details instead of inserting them
Deleting an Account
To delete an account, the user can click the Delete Account button that is shown under each account listing This activates the delete-accountaction
In the preprocessing section of the index.phpscript, we will execute the following code: case ‘delete-account’ :
{ delete_account($auth_user, $account);
break;
} This code calls the delete_account()function The code for this function is shown in Listing 27.6 Deleting accounts needs to be handled before the header because a choice of which account to use is inside the header The account list needs to be updated before this can be cor-rectly drawn
L ISTING 27.6 delete_account() Function from mail_fns.php—Function to Delete a Single Account’s Details
function delete_account($auth_user, $accountid) {
//delete one of this user’s accounts from the DB
$query = “delete from accounts where
accountid=’$accountid’ and username = ‘$auth_user’”;
if(db_connect()) {
$result = mysql_query($query);
} return $result;
}
Trang 3After execution returns toindex.php, the body stage will run the following code:
case ‘store-settings’ :
case ‘account-setup’ :
case ‘delete-account’ :
{
display_account_setup($auth_user);
break;
}
You will recognize this as the same code we ran before—it just displays the list of the user’s
accounts
Reading Mail
After the user has set up some accounts, we can move on to the main game: connecting to
these accounts and reading mail
Selecting an Account
We need to select one of the user’s accounts to read mail from The currently selected account
is stored in the $selected_accountsession variable
If the user has a single account registered in the system, it will be automatically selected when
he logs in, as follows:
if(number_of_accounts($auth_user)==1)
{
$accounts = get_account_list($auth_user);
$selected_account = $accounts[0];
session_register(“selected_account”);
}
Thenumber_of_accounts()function, from mail_fns.php, is used to work out whether the
user has more than one account The get_account_list()function retrieves an array of the
names of the user’s accounts In this case there is exactly one, so we can access it as the
array’s 0value
The number_of_accounts()function is shown in Listing 27.7
L ISTING 27.7 number_of_accounts() Function from mail_fns.php—Function to Work Out
How Many Accounts a User Has Registered
function number_of_accounts($auth_user)
{
// get the number of accounts that belong to this user
27
Trang 4$query = “select count(*) from accounts where username = ‘$auth_user’”; if(db_connect())
{
$result = mysql_query($query);
if($result) return mysql_result($result, 0, 0);
} return 0;
}
The get_account_list()function is similar to the get_accounts()function we looked at before except that it only retrieves the account names
If a user has multiple accounts registered, he will need to select one to use In this case, the headers will contain a SELECTthat lists the available mailboxes Choosing the appropriate one will automatically display the mailbox for that account You can see this in Figure 27.5
L ISTING 27.7 Continued
F IGURE 27.5
After the localhost account is selected from the SELECTbox, the mail from that account is downloaded and displayed.
Trang 5This SELECToption is generated in the do_html_header()function from output_fns.php, as
shown in the following code fragment:
<?
// include the account select box only if the user has more than one account
if(number_of_accounts($auth_user)>1)
{
echo “<form target=’index.php?action=open-mailbox’ method=post>”;
echo ‘<td bgcolor = “#ff6600” align = right valign = middle>’;
display_account_select($auth_user, $selected_account);
echo ‘</td>’;
echo “</form>”;
}
?>
We have generally avoided discussing the HTML used in the examples in this book, but the
HTML generated by the function display_account_select()bears a visit
Depending on the accounts the current user has,display_account_select()will generate
HTML like this:
<select onchange=window.location=this.options[selectedIndex].value name=account>
<option value = 0 selected>
Choose Account</a>
<option value = ‘index.php?action=select-account&account=10’>
mail.domain.com
</option>
<option value = ‘index.php?action=select-account&account=11’>
mail.server.com
</option>
<option value = ‘index.php?action=select-account&account=9’>
localhost
</option>
</select>
Most of this code is just an HTML select element, but it also includes a little JavaScript In the
same way that PHP can generate HTML, it can also be used to generate client-side scripts
Whenever a change event happens to this element, JavaScript will set window.locationto the
value of the option If your user selects the first option in the select,window.locationwill be
set to ‘index.php?action=select-account&account=10’ This will result in this URL being
loaded Obviously, if the user has a browser that does not support JavaScript or has JavaScript
disabled, this code will have no effect
The display_account_select()function, from output_fns.php, is used to get the available
account list and display the SELECT It also uses the get_account_list()function we
dis-cussed previously
27
Trang 6Choosing one of the options in the SELECTactivates the select_accountevent If you look at the URL in Figure 27.5, you can see this appended to the end of the URL, along with the account ID of the chosen account
This has two effects First, in the preprocessing stage of index.php, the chosen account will be stored in the session variable $selected_account, as follows:
case ‘select-account’ : {
// if have chosen a valid account, store it as a session variable if($account&&account_exists($auth_user, $account))
{
$selected_account = $account;
session_register(‘selected_account’);
} } Second, when the body stage of the script is executed, the following code will be executed: case ‘select-account’ :
case ‘view-mailbox’ : {
// if mailbox just chosen, or view mailbox chosen, show mailbox display_list($auth_user, $selected_account);
break;
}
As you can see, we take the same action here as if the user had chosen the View Mailbox option We’ll look at that next
Viewing Mailbox Contents
Mailbox contents can be viewed with the display_list()function This displays a list of all the messages in the mailbox The code for this function is shown in Listing 27.8
L ISTING 27.8 display_list() Function from output_fns.php—Function to Display All Mailbox Messages
function display_list($auth_user, $accountid) {
// show the list of messages in this mailbox global $table_width;
if(!$accountid) {
Trang 7echo “No mailbox selected<br><br><br><br><br><br>.”;
}
else
{
$imap = open_mailbox($auth_user, $accountid);
if($imap) {
echo “<table width = $table_width cellspacing = 0
cellpadding = 6 border = 0>”;
$headers = imap_headers($imap);
// we could reformat this data, or get other details using // imap_fetchheaders, but this is not a bad summary so we just echo each
$messages = sizeof($headers);
for($i = 0; $i<$messages; $i++) {
echo “<tr><td bgcolor = ‘“;
if($i%2) echo “#ffffff”;
else echo “#ffffcc”;
echo “‘><a href =’index.php?action=view-message&messageid=”.($i+1).”’>”;
echo $headers[$i];
echo “</a></td></tr>\n”;
} echo “</table>”;
} else {
$account = get_account_settings($auth_user, $accountid);
echo “could not open mail box “.$account[‘server’].”.<br><br><br><br>”;
} }
}
In this function, we actually begin to use PHP’s IMAP functions The two key parts of this
function are opening the mailbox and reading the message headers
27
L ISTING 27.8 Continued
Trang 8We open the mailbox for a user account with a call to the open_mailbox()function that we have written in mail_fns.php This function is shown in Listing 27.9
L ISTING 27.9 open_mailbox() Function from mail_fns.php—This Function Connects to a User Mailbox
function open_mailbox($auth_user, $accountid) {
// select mailbox if there is only one if(number_of_accounts($auth_user)==1) {
$accounts = get_account_list($auth_user);
$selected_account = $accounts[0];
session_register(“selected_account”);
$accountid = $selected_account;
} // connect to the POP3 or IMAP server the user has selected
$settings = get_account_settings($auth_user, $accountid);
if(!sizeof($settings)) return 0;
$mailbox = “{“.$settings[server];
if($settings[type]==’POP3’)
$mailbox = ‘/pop3’;
$mailbox = “:”.$settings[port].”}INBOX”;
// suppress warning, remember to check return value
@ $imap = imap_open($mailbox, $settings[remoteuser],
$settings[remotepassword]);
return $imap;
}
We actually open the mailbox with the imap_open()function This function has the following prototype:
int imap_open (string mailbox, string username, string password [, int flags])
The parameters you need to pass to it are as follows:
• mailbox—This string should contain the server name and mailbox name, and optionally
a port number and protocol The format of this string is
{hostname/protocol:port}boxname
Trang 9If the protocol is not specified, it defaults to IMAP In the code we have written, you can see that we specify POP3 if the user has specified that protocol for a particular account
For example, to read mail from the local machine using the default ports, we would use the following mailbox name for IMAP
{localhost:143}INBOX and this one for POP3 {localhost/pop3:110}INBOX
• username—The username for the account
• password—The password for the account You can also pass it optional flags to specify options such as “open mailbox in read-only
mode”
One thing to note is that we have constructed the mailbox string piece by piece with the
con-catenation operator before passing it to imap_open() You need to be careful how you construct
this string because strings containing {$cause problems in PHP 4
This function call returns an IMAP stream if the mailbox can be opened, and falseif it cannot
When you are finished with an IMAP stream, you can close it using imap_close(imap_stream)
In our function, the IMAP stream is passed back to the main program We then use the
imap_headers()function to get the email headers for display:
$headers = imap_headers($imap);
This function returns header information for all mail messages in the mailbox we have
con-nected to The information is returned as an array, one line per message We haven’t formatted
this It just outputs one line per message, so you can see from looking at Figure 27.5 what the
output looks like
You can get more information about email headers using the confusing, similarly named
imap_header() In this case, the imap_headers()function gives us enough detail for our
purpose
Reading a Mail Message
We have set up each of the messages in the previous display_list()function to link to
specific email messages
Each link is of the form
index.php?action=view-message&messageid=6
27
Trang 10The messageidis the sequence number used in the headers we retrieved earlier Note that IMAP messages are numbered from 1, not 0
If the user clicks one of these links, he will see output like that shown in Figure 27.6
F IGURE 27.6
Using the view-messageaction shows us a particular message—in this case, it’s a piece of spam.
When we enter these parameters into the index.phpscript, we execute the following code: case ‘show-headers’ :
case ‘hide-headers’ : case ‘view-message’ : {
// if we have just picked a message from the list, or were looking at // a message and chose to hide or view headers, load a message
$fullheaders = ($action==’show-headers’);
display_message($auth_user, $selected_account, $messageid,
$fullheaders) break;
} You’ll notice that we’re checking the value of the $actionbeing equal to ‘show-headers’ In this case, it will be false, and $fullheaderswill be set equal to false We’ll look at the
‘show-headers’action in a moment