Notice how I do a close of the query after calling the Content method. This is because as I've mentioned, once a request is serviced, the web-module remains in memory waiting for other request (CacheConnections = True). If we didn't close the query after calling the Content method, the next request would just call Content and not refresh the query with the new parameters of the request.

Next, we'll take a look at the OnFormatCell event of the TQueryTableProducer. This event gets fired for every cell. We are going to use this event to add a link to the ID of the client so as the user can click on it to consult and/or modify the record. We will also add a checkbox in the last column of the table so we can use it do delete the record. The first check is to see if we are not in the Title row (CellRow >0). If not, we then add certain data depending on the row we are in. If it is the Client_id column, we add a link to call the action?target=consultrecord&client_id=XXX. This will call the action ConsultRecord given the parameter client_id. The other column adds a checkbox with name 'DEL' + Client_id. We'll see how to make use of this in the next section.

One last thing: Take a look at the header and footer properties of the qtpSEARCH component. I have added the necessary html tags to incorporate a form so we can process the values returned by the checkboxes.

Consulting and modifying a record: The TDataSetPageProducer

Up to this point, we have an action that returns a list of records in an HTML table with a link to consult/modify the record and a checkbox to delete the record. In this section will see how to modify and consult the record. The call to "consultrecord" is basically the same as the previous action. The difference here is that we use a TDataSetPageProducer as the response. This component is used to produce the values of a record in the dataset. What it does is replace all the tags in an html page that have the same name as a field in the dataset with their values. If you take a look at the modify.htm file you will see how I used <#FIELD_NAME> tags to fill in the edit boxes with the current value of the record. Certain fields might need additional processing such as memo fields or checkbox fields, drop-down lists, etc. All this processing can be done in the OnHTMLTag event.

So, this action retrieves the information from the database based on the value passed in the query and produces the modify.htm page as the result, filling in the appropriate values. This page is contained in a form. By clicking on the Modify button you can modify the record with the current contents. This is performed by the "modifyrecord" target of the Action event. This event is very similar to AddRecord.

Deleting records
As we saw in the search section, I added a checkbox so the user can select the records to delete. When you submit a form that contains a checkbox, if the checkbox is ticked, a corresponding ContentField is available with the value of the checkbox. If it is not ticked then the ContentFields is not present. I make use of this feature to construct and SQL sentence with the records needed to delete. I loop through the ContentFields and see if any of have DEL in them. If so, I subtract the record number and construct the SQL sentence. Executing this sentence will delete the corresponding records. Of course, this method is not foolproof if you have other fields beginning with DEL or containing DEL but it allows me to show you how you can do something similar.

CONCLUSION
Well, that's about it! This is the last chapter of this tutorial (until I expand it). I hope it has been useful and will allow you to get started on Internet programming with Delphi. It's now 6 am and I have to get up in two hours for work, so I'm going to stop here!

Good luck and PLEASE send me your feedback!