if, else, endif

Article
05/31/2018

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HTML extension files can contain conditional logic with an if-then-else statement to control how the webpage is constructed. For example, one common usage is to insert a condition to display a header for the query on the first row within a <%begindetail%> section. If there are no records returned by the query, the HTML extension file displays the text ?Sorry, no authors had YTD sales greater than? %sales%. By using the <%if%> statement and a built-in variable called CiLastRecordNumber, you can tailor the output so that the error message is printed when no records are returned. Here is an example showing the use of the <%if%> statement.

<%begindetail%> 
      <%if CiCurrentRecordNumber EQ 1%> 
        Query results:
        <B>Author YTD Sales<BR></B>
      <%endif%> 
      <%au_lname%>$<%ytd_sales%> 
    <%enddetail%> 
    <P>
    <%if CiLastRecordNumber EQ 0%> 
      <I><B>Sorry, no authors had YTD sales greater than </I><%sales%>.</B>
      <P>
    <%else%> 
    <HR>
      <I>
      The webpage you see here was created by merging the results
      of the Content query with the template file Sample.htx.
      <P>
      The merge was done by Indexing Service and
      the results were returned to this Web browser by 
      Internet Information Services (IIS).
      </I>
    <%endif%> 
    </BODY>
    </HTML>

The general syntax is:

<%if condition%> 
    HTML text
    [ <%else%> 
      HTML text ]
    <%endif%>

where the condition is of the form value1 operator value2 and operator can be one of the following:

EQ

if value1 equals value2

NE

if value1 does not equal value2

LT

if value1 is less than value2

LE

if value1 is less than or equal to value2

GT

if value1 is greater than value2

GE

if value1 is greater than or equal to value2

CONTAINS

if any part of value1 contains the string value2

ISTYPEEQ

allows the .htx file to determine the VT_TYPE of a particular variable.

value1 IsTypeEq value2 value1 IsTypeEq const1 const1 IsTypeEq value1

For example, if a variable is of type currency (VT_CY), its type is 6. Type numbers are defined in the ActiveX specification. A valid .htx comparison would be:

<%if propName IsTypeEq 6%>Variable is of type currency
<%else%>Variable is NOT type currency
<%endif%>

This operator is especially useful to check for type VT_EMPTY, an empty property.

ISEMPTY

TRUE if value1 is of type VT_EMPTY, or of type VT_NULL, or is of a textual type (VT_LPSTR, VT_LPWSTR, VT_BSTR, or vectors of the preceding types) and contains only ?empty? characters (space, tab, and so on.)

The operands value1 and value2 can be column names, one of the built-in variables, an HTTP variable name (see HTTP Variables), or a constant. When used in an <%if%> statement, values are not delimited with <% and %>. For example, to do special processing on author name ?Green,? use the condition:

<FORM ACTION="<%HTTP_SCRIPT_NAME%>?" METHOD="POST">
      <%if au_lname EQ "Green"%> 
        this guy is green!
      <%endif%> 
    <%enddetail%>

The <%if%> statement can also be used to do special processing based on information from HTTP variables. For example, to format a page differently for a different type of client Web browser (in this case, Netscape Navigator), you could include the following in the HTML extension file.

<%if HTTP_USER_AGENT contains "Mozilla"%> 
      client supports advanced HTML features
    <%else%> 
      client is <%HTTP_USER_AGENT%> 
    <%endif%>

Property types VT_FILETIME and VT_DATE can be compared within <%if%> statements. Use the following format:

<%if fileTime eq "yyyy/mm/dd hh:mm:ss:iii"%>File times are identical
<%endif%>

The time must be enclosed in quotes. The year must be a four-digit number (for example, 1996, not 96), and slashes and colons are required.

yyyy = year

mm = month ( 1=January, 12=December, and so on)

dd = day of month ( 1 - 31)

hh = hour of the day in 24-hour format (optional)

mm = minutes (optional)

ss = seconds (optional)

iii = milliseconds (optional)

For example:

<%if write le "1996/07/21 17:22:11:333"%>File times are identical
<%endif%>

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