Can I specify a range with the IntegerValidator attribute on a custom ConfigurationSection?

Question

I have a class containing the following ConfigurationSection:

namespace DummyConsole {
  class TestingComponentSettings: ConfigurationSection {

    [ConfigurationProperty("waitForTimeSeconds", IsRequired=true)]
    [IntegerValidator(MinValue = 1, MaxValue = 100, ExcludeRange = false)]
    public int WaitForTimeSeconds
    {
        get { return (int)this["waitForTimeSeconds"]; }
        set { this["waitForTimeSeconds"] = value; }
    }

    [ConfigurationProperty("loginPage", IsRequired = true, IsKey=false)]
    public string LoginPage
    {
        get { return (string)this["loginPage"]; }
        set { this["loginPage"] = value; }
    }
  }
}

I then have the following in my .config file:

<configSections>
  <section name="TestingComponentSettings" 
           type="DummyConsole.TestingComponentSettings, DummyConsole"/>
</configSections>
<TestingComponentSettings waitForTimeSeconds="20" loginPage="myPage" />

When I then attempt to use this configuration section I get the following error:

var Testing = ConfigurationManager.GetSection("TestingComponentSettings")
             as TestingComponentSettings;

ConfigurationErrorsException was unhandled

The value for the property 'waitForTimeSeconds' is not valid. The error is: The value must be inside the range 1-100.

If I change the IntegerValidator to have an ExcludeRage = true, I (obviously) get:

ConfigurationErrorsException was unhandled

The value for the property 'waitForTimeSeconds' is not valid. The error is: The value must not be in the range 1-100

If I then change the value of the property in the .config to a number higher than 100, it works.

If I change the validator to just have a MaxValue of 100 it works, but will also accept a value of -1.

Is it possible to use the IntegerValidatorAttribute with a range like this?

Edit to add

Confirmed as an issue by Microsoft.

Feet

The Microsoft link has been updated today with a solution. Apparently if a default value is not specified, it uses "0" as the default value. 0 is, of course, outside the range 1-100. The "solution" is to add a DefaultValue= parameter to the ConfigurationProperty attribute with a default value that is in the range. Unfortunately this means that you're imposing a default value which might not be what you want/need. I've been having this problem, too. Glad I stumbled across this question! – Eckstein

Answer 1

As Skrud points out, MS have updated the connect issue:

The reported issue is because of a quirk in how the configuration system handles validators. Each numeric configuration property has a default value - even if one is not specified. When a default is not specified the value 0 is used. In this example the configuration property ends up with a default value that is not in the valid range specified by the integer validator. As a result configuration parsing always fails.

To fix this, change the configuration property definition to include a default value that is within the range of 1 to 100:

[ConfigurationProperty("waitForTimeSeconds", IsRequired=true, 
                       DefaultValue="10")]

This does mean that the property will have a default, but I don't actually see that as a major issue - we're saying that it should have a value that falls within a "sensible" range, and should be prepared to set a sensible default.

Feet

This is what ended up working for me. In my case, I specifically wanted to require the option to be specified in the config file, so I didn't want to set a default value. But, it turns out that if you mark a field as required that fact takes precedence and the default value is never actually used except to keep validation from firing prematurely. It's a little counter-intuitive, but it works. – Nigger