<if> Task

<if>

Checks the conditional attributes and executes the children if true.

If no conditions are checked, all child tasks are executed.

If more than one attribute is used, they are &&'d. The first to fail stops the check.

The order of condition evaluation is, targetexists, propertyexists, propertytrue, uptodatefile.

Note: instead of using the deprecated attributes, we advise you to use the following functions in combination with the test attribute:

Function	Description
property::exists()	Checks whether the specified property exists.
target::exists()	Checks whether the specified target exists.

Parameters

Attribute	Type	Description	Required
comparefile	string	Deprecated. The file to check against for the uptodate file.	False
propertyexists	string	Deprecated. Used to test whether a property exists.	False
propertytrue	string	Deprecated. Used to test whether a property is true.	False
targetexists	string	Deprecated. Used to test whether a target exists.	False
test	string	Used to test arbitrary boolean expression.	False
uptodatefile	string	Deprecated. The file to compare if uptodate.	False
failonerror	bool	Determines if task failure stops the build, or is just reported. The default is true.	False
if	bool	If true then the task will be executed; otherwise, skipped. The default is true.	False
unless	bool	Opposite of `if`. If false then the task will be executed; otherwise, skipped. The default is false.	False
verbose	bool	Determines whether the task should report detailed build log messages. The default is false.	False

Nested Elements:

Deprecated. The <fileset> that contains the comparison files for the uptodatefile(s) check.

</comparefiles>

Deprecated. The <fileset> that contains the uptodate files for the comparefile(s) check.

Examples

Tests the value of a property using expressions.

<if test="${build.configuration=='release'}">
    <echo>Build release configuration</echo>
</if>

Tests the the output of a function.

<if test="${not file::exists(filename) or file::get-length(filename) = 0}">
    <echo message="The version file ${filename} doesn't exist or is empty!" />
</if>

(Deprecated) Check that a target exists.

<target name="myTarget" />
<if targetexists="myTarget">
    <echo message="myTarget exists" />
</if>

(Deprecated) Check existence of a property.

<if propertyexists="myProp">
    <echo message="myProp Exists. Value='${myProp}'" />
</if>

(Deprecated) Check that a property value is true.

<if propertytrue="myProp">
    <echo message="myProp is true. Value='${myProp}'" />
</if>

(Deprecated) Check that a property exists and is true (uses multiple conditions).

<if propertyexists="myProp" propertytrue="myProp">
    <echo message="myProp is '${myProp}'" />
</if>

which is the same as

<if propertyexists="myProp">
    <if propertytrue="myProp">
        <echo message="myProp is '${myProp}'" />
    </if>
</if>

(Deprecated) Check file dates. If myfile.dll is uptodate, then do stuff.

<if uptodatefile="myfile.dll" comparefile="myfile.cs">
    <echo message="myfile.dll is newer/same-date as myfile.cs" />
</if>

<if uptodatefile="myfile.dll">
    <comparefiles>
        <include name="*.cs" />
    </comparefiles>
    <echo message="myfile.dll is newer/same-date as myfile.cs" />
</if>

<if>
    <uptodatefiles>
        <include name="myfile.dll" />
    </uptodatefiles>
    <comparefiles>
        <include name="*.cs" />
    </comparefiles>
    <echo message="myfile.dll is newer/same-date as myfile.cs" />
</if>

Requirements

Assembly: NAnt.Core (0.91.4312.0)