一个免费的邮件列表源程序(三)

核心提示：Subscribe.asp<%@ Language=javaScript %> <!--#include file = "include/SetGlobals.asp"--> <!--#include file = "include/DBPath.asp&qu

Subscribe.asp
<%@ Language=javaScript %>

<!--#include file = "include/SetGlobals.asp"-->
<!--#include file = "include/DBPath.asp"-->

<%
// output relevant meta tags
Init( "Subscription" );

// output common top of page
Header( '<a href="work.asp">Work</a> --> Subscription', 3 );

// output page content
Content ( );

// output common bottom of page
Footer( );
%>

<% /* standard page elements */ %>
<!--#include file = "utils/Init.asp"-->
<!--#include file = "utils/Database.asp"-->
<!--#include file = "utils/Header.asp"-->
<!--#include file = "utils/Footer.asp"-->

<%
// ============================================
// the content of this page
// ============================================
function Content ( )
{
　 Out ( '<td width="20%"> </td>' );
　 Out ( '<td width="60%">' );
　　
　　　// if the form has an email address, validate it first
　　　// so that if it fails we can show the form to fix
　　　var sEmail = "";
　　　var bSubmitted = (Request.Form.Count > 0);

　　　// has the form been submitted?
　　　if ( bSubmitted )
　　　{
　　　　 // get the email address from the form...
　　　　　sEmail = "" + Request.Form ( "email" );

　　　　 // validate the email address and moan if it fails
　　　　 if ( !IsValidEmail ( sEmail ) )
　　　　 {
　　　　　　Out ( '<h5><font color="red">"' + sEmail + '" <i>appears</i> to be an invalid email address - please try again!</font></h5>' );
　　　　　　Out ( '<p><font color="red">If you disagree, please <a href="Contact.asp">contact me</a> directly.</font><p>' );
　　　　　　// PRetend the form hasn'\t been sent yet
　　　　　　bSubmitted = false;
　　　　 }
　　　}

　　　// show the form if not submitted yet
　　　if ( !bSubmitted )
　　　{
　　　　 Out ( 'If you\'re interested in hearing whenever a new article is posted, or an existing one is updated, type in your email address below and hit <b>Subscribe!</b>' );
　　　　 Out ( '<p>Whenever you want to stop receiving my emails, guess what? That\'s right, enter your email address and hit <b>Unsubscribe</b>...' );
　　　　 Out ( '<p><i>Your email address will never sold to or otherwise used by any third party, just me.</i>' );

　　　　 // here's the form tag. the action attribute is the name of
　　　　 // the file that will be called with the answer - in this case
　　　　 // it's the same page. the method can be "post" to send the
　　　　 // form data 'behind the scenes' or "get" to appending the
　　　　 // data to the URL in the style page.asp?data1=a&data2=b
　　　　 //
　　　　 // use post most of the time - it's neater and "get" is limited
　　　　 // in the amount of data that can be sent.
　　　　 Out ( '<center><form action="Subscribe.asp" method="post">' );
　　
　　　　　　// another table to line up the titles and inputs
　　　　　　Out ( '<table border="0" cellpadding="0">' );
　　　　　　Out ( '<tr><td align="right" valign="top">' );
　　　　　　　 Out ( 'Email:' );
　　　　　　Out ( '</td><td align="left" valign="top">' );
　　　　　　　 // a simple text box. we'll reference it with the name "name"
　　　　　　　 // and show 22 characters on the form. use the maxlength
　　　　　　　 // attribute to set the maximum characters they can enter.
　　　　　　　 // use value="some text" to pre-fill the input with data.
　　　　　　　 //
　　　　　　　 // IMPORTANT! using names that are commonly used by
　　　　　　　 // other web sites has a big advantage to the user - IE
　　　　　　　 // will drop down a list of previous answers, which they
　　　　　　　 // can usually pick from rather than type in. Think about this.
　　　　　　　 Out ( '<input type="text" name="email" size="31" value="' + sEmail + '"></input>' );
　　　　　　Out ( '</td></tr>' );

　　　　　　Out ( '<tr><td align="right" valign="top">' );
　　　　　　　 Out ( ' ' );
　　　　　　Out ( '</td><td align="left" valign="top">' );
　　　　　　　 // type='submit" provides a submit button to perform the
　　　　　　　 // form action. the button says "Submit" unless you override
　　　　　　　 // with the value attribute.
　　　　　　　 Out ( '<input type="submit" name="action" value="Subscribe"></input> <input type="submit" name="action" value="Unsubscribe"></input>' );
　　　　　　Out ( '</td></tr>' );

　　　　　　Out ( '</table>' );
　　　　 Out ( '</form></center>' );
　　　}
　　　else
　　　{
　　　　 var sAction = "" + Request.Form ( "action" );

　　　　 if ( sAction == "Subscribe" )
　　　　　　AddEmail ( sEmail ) ;
　　　　 else
　　　　　　RemoveEmail ( sEmail );

　　　　 Out ( '<p>' );
　　　}

　　　Out ( 'Do you want to see how this form adds and removes addresses to my database? All the source code is just a click away!' );
　　　Out ( '<p><center><a href="ShowSource.asp? page=Subscribe"><img src=http://www.cncms.com/"images/source.gif" border=0></a></center>' );
　　　Out ( '<p>In <a href="MailToList.asp">Part 2</a> see how I wrote a form to mail all my subscribers...' );

　 Out ( '</td>' );
　 Out ( '<td width="20%"> </td>' );
}

// ============================================
// validate email address
// ============================================
function IsValidEmail ( sEmail )
{
　 // regular expression courtesy of ed.courtenay@nationwideisp.net
　 // I won't even pretend that I've read through this yet!

　 if ( sEmail.search ( /\w+((-\w+)|(\.\w+)|(\_\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0- 9]+)*\.[A-Za-z]{2,5}/ ) != -1 )
　　　return true;
　 else
　　　return false;
}


// ============================================
// add email to database
// ============================================
function AddEmail ( sEmail )
{　　　 
　 // open the connection
　 DBInitConnection ( );

　 // first see if they are already subscribed
　 var sSQL = 'SELECT Email FROM MailingList WHERE Email="' + sEmail + '";';

　 DBGetRecords ( sSQL );

　 if ( !oRecordSet.EOF )
　 {
　　　Out ( '<h5><font color="red">' + sEmail + ' is already subscribed to my mailing list!</font></h5>' );
　　　return;
　 }

　 // this section needs more work - what should be done is that an email is
　 // sent to the email address, and only added to the database when we
　 // get a reply. that way we know the address is valid and the recipient
　 // really wants to join the list. for now though, we'll add to the db now.
　 sSQL = 'INSERT INTO MailingList (Email) VALUES ("' + sEmail + '");';

　 oConnection.Execute( sSQL );

　 // free the connection
　 DBReleaseConnection ( );

　 Out ( sEmail + ' has been successfully subscribed to my mailing list. ' );
　 Out ( '<p>You will now receive an email whenever I write new articles, or if I make an important update to any.' );

　 Email ( 'Joined the ShawThing mailing list', sEmail, 'You have successfully subscribed to the mailing list at ShawThing. If you didn\'t request this please reply to this email, or visit http://www.shawthing.com/subscribe.asp to unsubscribe.\n\nThank you.\n\nJames Shaw\nhttp://www.shawthing.com/' );
}


// ============================================
// remove email from database
// ============================================
function RemoveEmail ( sEmail )
{　　　 
　 // open the connection
　 DBInitConnection ( );

　 // first see if they are already subscribed
　 var sSQL = 'SELECT Email FROM MailingList WHERE Email="' + sEmail + '";';

　 DBGetRecords ( sSQL );

　 if ( oRecordSet.EOF )
　 {
　　　Out ( '<h5><font color="red">' + sEmail + ' isn\'t subscribed to my mailing list!</font></h5>' );
　　　return;
　 }

　 // delete from the database
　 sSQL = 'DELETE FROM MailingList WHERE Email="' + sEmail + '";';

　 oConnection.Execute( sSQL );

　 // free the connection
　 DBReleaseConnection ( );

　 Out ( sEmail + ' has been successfully removed from my mailing list. ' );
　 Out ( '<p>You have been sent a confirmation email, but after that you will not receive any more emails.' );

　 Email ( 'Removal from ShawThing mailing list', sEmail, 'You have been successfully removed from the mailing list at ShawThing. If you didn\'t request this please reply to this email, or visit http://www.shawthing.com/subscribe.asp to re-subscribe.\n\nThank you.\n\nJames Shaw\nhttp://www.shawthing.com/' );
}


// ============================================
// email me!
// ============================================
function Email ( sSubject, sEmail, sMessage )
{　 // send an email to the address just to confirm what just happened
　 var oMail = Server.CreateObject ( "CDONTS.NewMail" );

　 // setup the mail
　 oMail.From = 'DB@shawthing.com';

　 oMail.To = sEmail;
　 oMail.Importance = 1;

　 oMail.Subject = sSubject;
　 oMail.Body = sMessage;

　 // send it
　 oMail.Send ( );

　 // release object
　 oMail = null;
}
%>
　　 
utils/Database.asp
<%
// globals
var oConnection;
var oRecordSet;
var sConnection;

// ============================================
// example usage:
//　　　DBInitConnection ( );
//
//　　　var sSQL = "SELECT * FROM Somewhere";
//
//　　　DBGetRecords ( sSQL );
//
//　　　...use oRecordSet
//
//　　　DBReleaseRecords ( );　　　// optional step
//
//　　　DBReleaseConnection ( );
// ============================================

// ============================================
// initializes database variables for first use on page
// ============================================
function DBInitConnection ( )
{
　 // don't open it again if already opened!
　 if ( sConnection != undefined )
　　　return;
　　　 
　 // get connection object
　 oConnection = Server.CreateObject( 'ADODB.Connection' );

　 // get the database connection string
　 // use MapPath to make relative path into physical path
　 sConnection = 'Provider=Microsoft.Jet.OLEDB.4.0; Data Source=' + Server.MapPath ( sDBPath );

　 // open the connection
　 oConnection.Open( sConnection );

　 // as an attempt at optimization we now open
　 // the recordset here, not in DBGetRecords()
　 oRecordSet = Server.CreateObject ( 'ADODB.Recordset' );
}

// ============================================
// tidies up after DBInitConnection
// ============================================
function DBReleaseConnection ( )
{
　 // don't release the connection if not connected!
　 if ( sConnection == undefined )
　　　return;
　　　 
　 // as an attempt at optimization we now close
　 // the recordset here, not in DBReleaseRecords()
　 if ( oRecordSet.State != 0 )
　　　oRecordSet.Close();
　 oRecordSet = undefined;

　 oConnection.Close();
　 oConnection = undefined;
　　
　 sConnection = undefined;
}

// ============================================
// executes the passed in SQL statement
// and returns the oRecordSet object
// ============================================
function DBGetRecords ( sSQL )
{
　 // remember that this can fail if passed garbage, and hence
　 // 'oRecordSet' will already be 'closed'
　 oRecordSet = oConnection.Execute( sSQL );
}

// ============================================
// tidies up after DBGetRecords
// ============================================
function DBReleaseRecords ( )
{
　 // IMPORTANT: THIS FUNCTION INTENTIONALLY BLANK
　 // as an attempt at optimization we now open/close
　 // the recordset with the connection, not separately
　 // so all code was moved to DBReleaseConnection.
　　
　 // it is recommended that you still call this function as soon
　 // as the recordset is finished with.
　　
　 // note that it is assumed by the caller that it is legal
　 // to call DBReleaseConnection without calling this function
}
%>