Tables and Frames

Understanding Table Basics

Using Table Elements To build effective page templates, you must be familiar with the HTML table elements and attributes The <table> element contains the table information, which consists of table row elements <tr> and individual table data cells <td> These are the three elements you will use most frequently when you are building tables

Basic Table Code <table border="1“> <tr><td>Breed</td><td>Description</td><td>Group</td> </tr> <tr><td>French Bulldog</td><td>Loyal Companion</td> <td>Non-Sporting</td></tr> <tr><td>Wheaten Terrier</td><td>High energy, friendly</td> <td>Terrier</td></tr> <tr><td>English Pointer</td><td>Hunting companion</td> <td>Sporting</td></tr> <tr><td>Australian Cattle Dog</td><td>Guarding, herding</td> <td>Working</td></tr> </table>

Caption and Table Header <caption> lets you add a caption to the top or bottom of the table By default, captions display at the top of the table; you can use the align=“bottom” attribute to align the caption at the bottom of the table The <th> tag lets you create a table header cell that presents the cell content as bold and centered

Table Grouping Attributes The primary use of the grouping elements is to let you apply styles to groups of either rows or columns

Defining Table Attributes Table attributes let you further define a number of table characteristics You can apply attributes at three levels of table structure: global, row level, or cell level

Global Table Attributes Affect the entire table

Row-Level Table Attributes Affect the entire row

Cell-Level Table Attributes Affect only the contents of one cell

Spanning Columns The colspan attribute lets you create cells that span multiple columns of a table Column cells always span to the right

Spanning Rows The rowspan attribute lets you create cells that span multiple rows of a table Rows always span down

Formatting Tables

Choosing Relative or Fixed Table Widths Set relative table widths as percentages in the table width attribute If you choose relative table widths, your tables will resize based on the size of the browser window Set absolute table widths as pixel values in the table width attribute Fixed tables remain constant regardless of the browser window size

Determining the Correct Fixed Width for a Table The most common width for page template tables is approximately 975 pixels This width supports the 1024 x 768 screen resolution

Adding White Space in a Table You can add white space into a table with the cellpadding and cellspacing attributes

Removing Default Table Spacing Default spacing values are included in the table even when you don’t specify values for the table’s border, cellpadding, or cellspacing attributes Depending on the browser, approximately two pixels are reserved for each of these values You can remove the default spacing by explicitly stating a zero value for each attribute

Table Pointers for Well-Designed Tables

Table Pointers for Well-Designed Tables Write code that is easy to read Remove extra white spaces Center tables to adapt to different resolutions Stack tables for quicker downloading Avoid nested tables Use Cascading Style Sheets for table styles

Removing Extra Spaces Always remove any leading or trailing spaces in your table cell content These spaces cause problems when you try to join the contents of adjacent cells

Centering Tables Centering a fixed table makes it independent of resolution changes, because the table is always centered in the browser window

Stacking Tables Because of the way browsers display tables, it is better to build several small tables rather than one large one This technique, called stacking tables, also can simplify your table design task, because smaller tables are easier to work with

Avoid Nesting Tables Nesting tables is the practice of placing an entire table within a table cell Nested tables are not accessible to screen readers and other assistive devices This technique is being replaced by newer techniques such as CSS positioning

Creating a Page Template In this example you’ll see how to take a design sketch for a Web page and build a template for the page layout Figure 5-20 shows a sketch of the desired layout This layout is designed for a base screen resolution of 1024 x 768, so the table will be fixed at a width of 975 pixels

Creating a Page Template Notice that the basic structure of the table is three rows by four columns Each column uses 25% of the total width of the template Row spans and column spans break across the layout to provide visual interest

Building the Basic Table Structure Start by building the basic table structure, including all the cells and rows of the table As you customize the table you can remove extraneous cells as necessary The basic structure is a three-row by four-column table

Setting a Fixed Width One of the design characteristics of the template is a fixed width that does not depend on the user’s browser size or screen resolution To create this characteristic, use a pixel value in the table width attribute

Creating the Page Banner Cell The page banner cell is R1C1 This cell spans the four columns of the table using the colspan attribute

Creating the Feature Article Cell The feature article cell in the layout is R2C2, and spans two columns This column span requires the removal of one cell in row two to make room for the span

Creating the Link Column Cells The New Link and Linked Ads columns in the layout reside in cells R2C1 and R2C3 respectively These cells span rows 2 and 3 of the table The row spans require the removal of cells R3C1 and R3C4

Setting the Column Widths Column widths must be set in only one cell per column It’s also best to set the column widths in only one row of the table Setting the column width ensures that the text will wrap properly

Testing the Template To verify that your template works properly, populate it with test content Test the template in multiple browsers

Examples of Page Templates The following templates cover a variety of page layout needs You may choose to stack different templates on top of each other for more complex layouts

Summary Plan your tables by sketching them out first Use fixed table widths if you want to determine the size of your page rather than let the browser determine the width Use relative widths if you want to build tables that resize with the browser window, wrapping your content to fit Write table code that is easy to read, remove extra spaces, and choose whether to center or stack tables Avoid using nested tables and use CSS whenever possible to add presentation style to tables

Summary Work on your pages with the table borders turned on, which displays the cell boundaries When you are finished with your layout, you can turn the borders off Size your tables based on the page size you want to create Use 1024 x 768 as your base screen resolution In most cases you’ll set the width but not the height of your tables, allowing the content to flow down the page

Summary Test your work! Table settings, especially cell widths and heights, can vary based on the user’s browser

Frames

Frameset and Frames The <frameset> element is the container for the frameset code The cols and rows attributes let you specify the characteristics of the frameset You can specify a frameset as either cols or rows, but not both The <frame> element is an empty element The src attribute provides the location of the file that is displayed within the frame

Frameset Syntax (Rows) <frameset rows = “50%,50%”> <frame src = “top.htm”/> <frame src = “bottom.htm”/> </frameset>

Frameset Syntal (Columns) <frameset cols = “150,*”> <frame src = “left.htm”/> <frame src = “right.htm”/> </frameset>

Nested Frameset Syntax <frameset rows = "40,*"> <frame src = "topnav.htm"/> <frameset cols = "20%,80%"> <frame src = "left.htm"/> <frame src = "right.htm"/> </frameset>

Frame Usage No longer effective Must be careful of source html files Must be careful with hyperlink targetting Less flexibility in design Replaced by tables and then by CSS