RELEASE: FormattableObject an Aggregating reflection-based ToString() implementation

January 31, '05 Comments [3] Posted in ASP.NET | Internationalization | CodeRush

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Well, here you go, it's my implementation of a FormattableObject that I mentioned earlier. Take a look at the comments, Mark Miller had some great ideas, the best of which being a CodeRush plugin that handles the static analysis at design time and makes it harder to mess up these strings.

You can do this:

[Test]
public void MakePersonFormattedStringWithFormat()
{
    Person p = new Person();
    string foo = p.ToString("{BirthDate:D} My name is {FirstName} {LastName} and I'm cool.");
    Assert.AreEqual("Tuesday, January 22, 1974 My name is Scott Hanselman and I'm cool.", foo);
}

[Test]
public void MakePersonFormattedStringWithFormatAndChineseCulture()
{
    Person p = new Person();
    string foo = p.ToString("{BirthDate:D} My name is {FirstName} {LastName} and I'm cool.",new System.Globalization.CultureInfo("zh-cn"));
    Assert.AreEqual("1974?1?22? My name is Scott Hanselman and I'm cool.", foo);
}

You can either:

Derive your objects from FormattableObject and you get these ToString implementations for free

Implement a few ToString's and IFormattable yourself and delegate over to the static implementations in FormattableObject:

  
public string ToString(string format, System.IFormatProvider formatProvider)
{
    return Corillian.Voyager.Common.ObjectFormatString.ToString(this,format,formatProvider);
}
 
public string ToString(string format)
{
    return this.ToString(format,null);
}

Here you go, enjoy. If you don't, screw you. If you do, I take full credit.

FormattableObject 0.5 (11kb)

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About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. I am a failed stand-up comic, a cornrower, and a book author.

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Comments [3]

Permalink

Monday, January 31, 2005 8:22:22 AM UTC

Yes, it seems to work well with Japanese characters (environment) as well. I updated my blog entry after trying your code out.

http://www.vbaspcoder.com/PermaLink,guid,13fe24f3-7129-4b42-8d0b-253d8e829f60.aspx

vbNullString

Wednesday, February 02, 2005 1:48:57 PM UTC

It can be cleaner...
Instead of manually building the result string, you could use:

reg.Replace(aFormat, new MatchEvaluator(Evaluate));

The regex would be (no IgnoreCase needed): @"{([^}]+)}"

And:

string Evaluate(Match match)
{
string property = match.Groups[1].Value;
...
}

Diego Mijelshon

Thursday, February 24, 2005 10:48:37 PM UTC

Very nice!
I took your idea and slapped together a version that runs on datasets. Completely different implementation, nowhere near as spiffy as using reflection, but still with the human readable string goodness. It's at http://www.aigee.org/agblog/archives/762-Better-String.Format.html if anyone is interested. Try not to laugh too hard at the coded-in-5-minutes sloppy code :)

Dan F

Comments are closed.