A directory of data access products for Delphi




François PIETTE / Overbyte

Vendor’s Description (from Readme files, web site, etc.):

Did you already heard about MIDDLEWARE ? It’s the layer you put in the middle of your software architecture to make all bits talk together. I made a middleware called MidWare. It’s a set of components and units which allows you to create an application server and a client application in just a few minutes, without worrying about client connection, data formatting and all those little details which make a server and a client difficult to write.

A MidWare application server is based on:

  • A server component
  • An Object Request Broker
  • A set of server objects

A Midware client application is based on:

  • One or more application server client object

As you imagine, I have no doc ! But you get full source code and two sample applications: One server and one client. The demo server has 3 ‘server objects’:

  • One which convert data receive to uppercase and send it back to the client
  • One with a thread which does a lengthy request (just sleep for 5 seconds) One which access a TTable, fetch some data based on a key sent by the client and return the fetched data to the client.

The demo client is very simple: just a few edit boxes to let user enter some data and a few button to act on those datas.

There is a mailing list to discuss FPiette’s components (TWSocket, TTnCnx, TEmulVT, RasDial, TPop3Cli, and others). To subscribe send an EMail at majordomo@rtfm.be without subject line and with “subscribe twsocket” in the message body (without the quotes). You’ll receive an autorization message you have to reply. Then you’ll receive an acknowledgement and instructions to unsubscribe. Once you have been registered with the mailing list processor, you can send messages to twsocket@rtfm.be. Every subscriber will receive a copy of your message. I will respond, but anybody is welcometo respond to each other’s messages. So every body can share his expertize.

BDE Alternatives Guide Comments:

MIDware does not automate much of the three-tier development process - plan on doing some manual coding for things that would happen automatically with a more developed three-tier solution (such as DataSnap, ASTA, ADO, dbOverNet, RemObjects).

MIDware can used to make a very simple three-tier / thin client C/S application. It provides a server object that can receive commands over a TCP socket. You write code to respond to the command by running a query against a database, using the BDE or any of the DataSet based alternatives here. MIDware can take this result set and set it over the TCP connection.

You also write a client application that uses MIDware components to request data over a TCP connection; MIDware handles moving the data over the connection from your server to your client, and making the results available in the client using a TDataSet descendant, so you can use data-aware controls on the result. MIDware currently supports only string fields (on the client) and does not move schema information, just the data.

François has used MIDware to make an enterprisewide application that can be trivially deployed - it needs TCP/IP installed, but needs no other DLL or driver configuration on the client computers at all. It also therefore as a very light footprint on the client, since all the database processing occurs on the middle-tier server.