Home arrow Delphi-Kylix arrow Building Contact Detail Maintenance into a Mailing List Program with Borland Delphi
DELPHI-KYLIX

Building Contact Detail Maintenance into a Mailing List Program with Borland Delphi


A mailing list would not be of much use if you cannot add and remove contact addresses. Therefore, in this second part of a two-part tutorial on building a mailing list application using Borland Delphi, we are going to add the capability of maintaining contact details.

Author Info:
By: Leidago
Rating: 5 stars5 stars5 stars5 stars5 stars / 4
October 04, 2006
TABLE OF CONTENTS:
  1. · Building Contact Detail Maintenance into a Mailing List Program with Borland Delphi
  2. · Breaking Down the Code
  3. · Creating a New Group
  4. · The Less Complicated Code Bits

print this article
SEARCH DEVARTICLES

Building Contact Detail Maintenance into a Mailing List Program with Borland Delphi
(Page 1 of 4 )


A downloadable file for this article is available here.

Add two more forms to the project and save the units as new_contact and addresses. On the new contacts form, drop three edits (rename them edname, edemail and ednewgroup), two radio buttons (rename them rb1 and rb2), two statictext (name and email), two buttons (rename to btnAddContact and btnCancel) and a combobox (rename to cb). This is how the form should look:

On the form's onshow event, add the following code:

procedure TForm2.FormShow(Sender: TObject);
begin
 cb.Visible:=false;
 ednewgroup.Visible:=false;
end;

Because we only take the contact's name and email address, the form provides us with text fields that will take that information. The next step is to decide whether you want to add this contact to a group. To make the choices clearer, I've added two radio buttons, one asking if you want to add the new contact to a group and the other if you want to create a new group. You can choose one or the other but not both.

If you choose to add the contact to a group, a drop down box with the various group names in it will  appear. All you have to do is click on that name and then click on the "Add Contact" button. Below is the code for the Add Contact button:

procedure TForm2.btnAddContactClick(Sender: TObject);
var
gname:string;
new_id:integer;
grpid,newgrp:boolean;
begin
new_id:=0;
if (edname.text = '') or (edemail.Text = '') then begin
showmessage('Please enter a name and email address');
exit;
end;
//purpose: to get the groupID of the selected groupname
if rb1.Checked then begin
 if cb.Text <> '' then begin
 gname:=cb.Text;
//search for the groupID of the selected groupname 
 form1.query1.Close;
 form1.query1.SQL.Text:='SELECT groupID from groups WHERE
groupname=:thename';
 form1.query1.Parameters.ParamByName('thename').Value:=gname;
 form1.query1.Open;
//Check if the group id is greater than 0:
  if form1.query1.FieldByName('groupID').AsInteger > 0  then
  begin
  new_id:= form1.query1.FieldByName('groupID').AsInteger;
  grpid:=true;
  //Now insert the data into the database
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=new_id;
  form1.query1.ExecSQL;
  showmessage('New contact has been added');
    end
  else
  begin
  //the record with the selected name has not been found, set the
groupID to zero
  new_id:=0;
  //Now insert the data into the database
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName
('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName
('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=new_id;
  form1.query1.ExecSQL;
  showmessage('New contact has been added');
  grpid:=false;
  end;
  end
  else
  begin
//User did not select a name...
  showmessage('Please select a group name to add the new contact
to.'+#13#10+ 'If you do not see the group name on the list then
create a new group name by selecting the ''Create a New Group ''
option below.');
  exit;
  end;
  end;//end main IF
  if rb2.Checked then
  begin
//check that the new name is entered
  if ednewgroup.Text <> '' then begin
//add the new groupname to the groups table and get its ID
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO groups (groupname) values
(:edval)';
  form1.query1.Parameters.ParamByName('edval').Value:=ednewgroup.Text;
  form1.query1.ExecSQL;
  //now get the group id
  form1.query1.close;
  form1.query1.SQL.Text:='SELECT groupID from groups WHERE
groupname=:thename';
  form1.query1.Parameters.ParamByName
('thename').Value:=form2.ednewgroup.Text;
  form1.query1.Open;
  new_id:=form1.query1.fieldbyname('groupID').AsInteger;
  //insert the new groupname..
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName
('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName
('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=new_id;
  form1.query1.ExecSQL;
  showmessage('Both the new group: '+ednewgroup.Text+ ' and
contact: '+inttostr(new_id)+' has been added.');
  end
  else
  begin
  showmessage('Please enter a groupname.');
  exit;
  end;
  end;
  if not (rb1.Checked) and not (rb2.Checked) then
  begin
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName
('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName
('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=0;
  form1.query1.ExecSQL;
  showmessage('New contact has been added.');
  end;
  end;


blog comments powered by Disqus
DELPHI-KYLIX ARTICLES

- Loading an XML Document into the DOM
- Delphi Wrapper Classes and XML
- Delphi and the DOM
- Delphi and XML
- Internet Access: Client Service
- Finishing the Client for an Internet Access ...
- The Client for an Internet Access Control Ap...
- User Management for an Internet Access Contr...
- Important Procedures for an Internet Access ...
- Server Code for an Internet Access Control A...
- Constructing the Interface for an Internet A...
- Building a Server Application for an Interne...
- Building an Internet Access Control Applicat...
- Client Dataset: Working with Data Packets an...
- Using the Client Dataset in an N-Tiered Appl...

Watch our Tech Videos 
Dev Articles Forums 
 RSS  Articles
 RSS  Forums
 RSS  All Feeds
Write For Us 
Weekly Newsletter
 
Developer Updates  
Free Website Content 
Contact Us 
Site Map 
Privacy Policy 
Support 

Developer Shed Affiliates

 




© 2003-2017 by Developer Shed. All rights reserved. DS Cluster - Follow our Sitemap
Popular Web Development Topics
All Web Development Tutorials