When a Variable is not found

The default behaviour for when a variable is not found is to replace the variable placeholder with a string that indicates this.

For example, if the variable name has not been added then a source string of Hi $(name) would result in a value of Hi NOTFOUND:name

The following examples show how to customise this behaviour.

WhenVariableNotFound

This method can be used to customise the message returned.

Note

Your method could throw an exception rather than return a replacement

var replacer = new VariableReplacerFactory()
    .Build(c => c.WhenVariableNotFound(variableName => $"ERROR:{variableName}"));

var result = replacer.ReplaceVariables("Hello $(Unknown)");

// result will be "Hello ERROR:Unknown"

ThrowIfVariableNotFound

This method will ensure an ArgumentException is thrown if a variable is not found. The message of the exception would be Variable 'Unknown' not found when the missing variable is called Unknown.

The following example shows how to set it up:

var sut = new VariableReplacerFactory()
    .Build(c => c.ThrowIfVariableNotFound());

// The following code will throw an ArgumentException
var result = sut.ReplaceVariables("Hello $(Unknown)");