- 7.1 Tag Library Components
- 7.2 Example: Simple Prime Tag
- 7.3 Assigning Attributes to Tags
- 7.4 Example: Prime Tag with Variable Length
- 7.5 Including Tag Body in the Tag Output
- 7.6 Example: Heading Tag
- 7.7 Example: Debug Tag
- 7.8 Creating Tag Files
- 7.9 Example: Simple Prime Tag Using Tag Files
- 7.10 Example: Prime Tag with Variable Length Using Tag Files
- 7.11 Example: Heading Tag Using Tag Files
This chapter is from the book
This chapter is from the book
This chapter is from the book
7.11 Example: Heading Tag Using Tag Files
In this section, we rewrite the heading example of Section 7.6 (Example: Heading Tag) with a JSP-based custom tag. Outputting the tag body inside a tag file is as simple as providing a <jsp:doBody/> tag. That's it! No additional configurations, no TLD file, and the access to attributes is still the same simple process described in Section 7.10 (Example: Prime Tag with Variable Length Using Tag Files). Just place <jsp:doBody/> where you want the tag body to appear in the final output and you are done.
Listing 7.21 shows the heading2.tag file. It declares quite a number of required attributes and then proceeds to use them as regular scoped variables. We use <jsp:doBody/> to output the body of the tag to the client. Listing 7.22 shows the headings-2.jsp file, which uses the heading2.tag custom tag. Figure 7-8 shows the result of headings-2.jsp.
Listing 7.21. heading2.tag
<%@ attribute name="align" required="true" %>
<%@ attribute name="bgColor" required="true" %>
<%@ attribute name="border" required="true" %>
<%@ attribute name="fgColor" required="true" %>
<%@ attribute name="font" required="true" %>
<%@ attribute name="size" required="true" %>
<TABLE ALIGN="${align}"
BGCOLOR="${bgColor}"
BORDER="${border}">
<TR><TH>
<SPAN STYLE="color: ${fgColor};
font-family: ${font};
font-size: ${size}px">
<jsp:doBody/></SPAN>
</TABLE><BR CLEAR="ALL"><BR>
Listing 7.22. headings-2.jsp
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD><TITLE>Headings</TITLE>
<LINK REL=STYLESHEET
HREF="JSP-Styles.css"
TYPE="text/css">
</HEAD>
<BODY>
<%@ taglib tagdir="/WEB-INF/tags" prefix="csajsp" %>
<csajsp:heading2 align="LEFT" bgColor="CYAN"
border="10" fgColor="BLACK"
font="Arial Black" size="78">
First Heading
</csajsp:heading2>
<csajsp:heading2 align="RIGHT" bgColor="RED"
border="1" fgColor="YELLOW"
font="Times New Roman" size="50">
Second Heading
</csajsp:heading2>
<csajsp:heading2 align="CENTER" bgColor="#C0C0C0"
border="20" fgColor="BLUE"
font="Arial Narrow" size="100">
Third Heading
</csajsp:heading2>
</BODY></HTML>
)
Figure 7-8 Result of headings-2.jsp.