Dreamweaver.MX.1002004.The.Missing.Manual [Electronic resources] نسخه متنی

22.6 Master Detail Page Set

A common task when building a database-driven Web site is providing your visitors
with both an overview and detailed view of information. Usually, it takes two separate
Web pages to do the job: One that lists limited information about all records in
a recordset, and one that links to a second page with detailed information about a
single record. Dreamweaver calls these master and detail pages and provides a tool
for making quick work of this task (see Figure 22-17).

An example of Dreamweaver's
Master Detail Page
Set. The screen on the left
represents a master page
a list of items retrieved from
a recordset. Clicking a link on
this page opens a detail page
(right), which displays the
details of a single record.

The Master Detail Page Set object automates the process of creating dynamic tables
and recordset navigation bars, as well as adding many different server behaviors to
your pages. In fact, there's nothing this tool does that you can't do (albeit more slowly)
with the other tools you've learned about in this chapter.

NOTE

The Master Detail Page Set object is not available for the ASP.NET server model.

To create a Master Detail Page set, follow these steps:

Create two Web pagesone for the master page and another for the detail
page.

They can be new, blank pages, or existing pages that require the dynamic information
from the database. It helps to use descriptive names for these pages, such as
"productIndex.asp" and "productDetails.asp." (Save each page with an extension
appropriate for the server model you're using: .asp, .cfm, .php or .jsp.)

Open the master pagethe one listing all of the recordsand add a recordset
to it.

This recordset must include not only all of the columns to be displayed on the
master page, but also all of the columns to appear on the detail page. Both pages use
the same recordset, so all information you want on both pages must be retrieved
by this one recordset.

In the Application tab of the Insert bar, click the Master Detail Page Set button
(see Figure 22-1).

The Insert Master-Detail Page Set window lets
you quickly create two common types of dynamic
pages: one that lists many records in a database,
and another that shows detailed information about
a single database record. Unfortunately, this tool
is not available in the ASP.NET and PHP/MySQL
server models in Dreamweaver.

You can also choose InsertApplication ObjectsMaster Detail Page Set. Either
method opens the Insert Master-Detail Page Set window (see Figure 22-18).

From the Recordset pop-up menu, chose the name of the recordset you created
in step 2.

Select the fields (database columns) you wish to appear on the master page.

You'll most likely remove a bunch of columns from the Master Page Fields box,
since most of the information is reserved for the detail page. To remove a column,
click its name to select it and click the button. (If you accidentally delete
a column, click the + button to add it back.) You can also change the order of the
columns by selecting a column name and clicking the up or down arrow buttons.
The order the fields are listed in the box dictates the order in which they appear
on the master page.

From the Link to Detail From pop-up menu, choose a column.

Here you're determining which item on the master page is linked to the detail
page. In Figure 22-17, the name of each product has a link to the detail page. If
you were creating a staff directory, you might select the column that contained
each staff member's name. In this way, visitors could click a name to see a page
with that staff person's details.

Using the Pass Unique Key field, select a column.

Choose a column that uniquely identifies a single record in the database, such as
a product identification number or Social Security number. In most cases, this is
the primary key in a database table (see Section 21.4.2).

Select how many records you wish to show.

You can either type a number into the "Records at a Time" box or select All
Records.

Click Browse. Select the detail page you created in step 1.

In this step and the next, you're defining the detail page and what information
appears on it.

Select the fields you wish to display on the detail page.

The process is the same as step 5, but in this case, you'll probably include most, if
not all, of the columns. After all, the detail page is where most of the information
for an individual record shows up.

Click OK to close the window and create the pages.

It may take a few moments for Dreamweaver to complete this step. It's adding a
lot of code to both the master and detail pages.

Once completed, you can (and should) modify the tables, format the dynamic items,
and design the page to your liking. Because the Master Detail Page Set tool just automates
the process of adding repeating regions, recordset navigation bars, and other
server behaviors, you must edit those items individually on the page. In other words,
you can't return to the Insert Master-Detail Page Set window (Figure 22-18) to alter
items on either page. For example, if you decide to remove a piece of dynamic information
from the detail page, you must make this change on the detail page itself.

While the Master Detail Page Set tool makes building these types of pages a snap, it
does have its drawbacks. The primary problem is that Dreamweaver uses the same
recordset for both the master and detail pages. This can slow down the works, because
even though you may want to display only a few columns of data on the master page
(the prodName, prodID, and prodPrice fields in Figure 22-17), the recordset added
to the page must retrieve all of the information required by the detail page. The
database server is doing a lot of extra work retrieving unused data. However, there is
a workaround: On the master page, edit the recordset and select only the fields that
that page uses. (Editing recordsets is described in Section 22.1.8.)

Although the Master Detail Page Set makes quick work of creating these types of
pages, you can do all the same tasks using the tools you've already learnedrepeating
regions, recordset navigation bars, and so onwith the added benefit of greater
design flexibility. For an example of creating a more complex master and detail page
set by hand, complete the tutorial at the end of this chapter.