Table 69. XSLT Instruction Blocks in XSLT Mapper
XSLT Instruction	Meaning of Input Port
xsl:value-of	Used to define the value of the `select` attribute. For example: `<xsl:value-of select="'Owen'">`
xsl:for-each	Used to define the XPath expression for the `select` attribute. For example: `<xsl:for-each select="books/book">`
xsl:if	Used to define the value of the `test` attribute. For example: `<xsl:if test="authors/author= 'Henry'">` See xsl:if and xsl:choose to learn more about when to use this instruction.
xsl:choose	Used to define the value of the `test` attribute of the nested `xsl:when` element. For example: `<xsl:when test="contains(authors/author,'Marchese')">` See xsl:if and xsl:choose to learn more about when to use this instruction.
xsl:apply-templates	Used to define the value of the `select` attribute. For example: `<xsl:apply-templates select="subject"/>`
xsl:call-template	Used to define the value of the `name` attribute. For example: `<xsl:call-template name="newAuthorsTemplate"/>`

Tip		When you mouse over an input port, Stylus Studio displays the value associated with that port.

Red Input Ports

If an xsl: instruction's attribute takes a literal or string value (such as xsl:value-of select="'Recommended'"/, for example) and a value has been provided for the attribute, Stylus Studio fills the input port associated with that attribute with a deep red to indicate that a value has been specified.

Understanding Input Ports

Specifying Values for Input Ports

Red Input Ports