xpath expression to conditonally build column with URL

Question

I am trying to create a formula for a dataview that returns a URL using the xpath expression tool in SPD 2007. I can't really find any examples. Here is what I am trying to do (in pseudo code):

If @ColumnA='SomeValue' then

// build a link to a web page and display it in the column
'<a href=http://mysite/somePage.aspx?ParamB=' + @ColumnB + '&ParamC=' + @ColumnC + '>Complete Request</a>'

else

// display nothing in the column
''

end

The url should look like this:

http://abc-company/somepage.aspx?ParamB=1234&ParamC=ABCD

and displayed in the dataview list column as a URL (if condition is true) labeled "Complete Request"

Answer 1

So the way I did this was to just add a simple formula column. Then, in the markup, I replaced what was added by the designer with this:

<xsl:choose>
<xsl:when test="@OARP_x0020_Approval_x0020_Status='Initializing'">
    <td class="ms-vb">
        <xsl:element name="a">
            <xsl:attribute name="href">
                <xsl:value-of select="concat(concat('oracleResponsibilities.aspx?GUID=',@Guid_Id),concat('&amp;ID=',@ID))"/>
            </xsl:attribute>
            <xsl:text>Complete Request</xsl:text>
        </xsl:element>
    </td>
</xsl:when>
<xsl:otherwise>
    <td class="ms-vb"></td>
</xsl:otherwise>

Basically, if the value of column "OARP Approval Status" is 'Initializing', then I construct the anchor tag. If "OARP Approval Status" is any other value, I just leave the table cell blank.

The following creates the anchor tag:

<xsl:element name="a"></xsl:element>

This sets the href attribute:

<xsl:attribute name="href">
    <xsl:value-of select="concat(concat('oracleResponsibilities.aspx?GUID=',@Guid_Id),concat('&amp;ID=',@ID))"/>
</xsl:attribute>

And this sets the display value fo the link:

<xsl:text>Complete Request</xsl:text>