Add a "RegEx Formatter" extension

[krptodr]

I have a list of nested objects and I'd like to get to provide some sort of condition on it so it knows which list item to grab.

Smart.Format("{User.Address.Where(Zip=55555):{Street}, {City}, {State} {Zip}}", data)

My list can return entirely different things depending on a foreign relationship.

[ericpyle]

I'm trying to do the same thing. I'd like to apply a template to an item in a list depending upon the string value of a property. I can use a choose() to get one item, but if I need more than that I have to repeat the template for each additional comparision.
{mylist:list:{myproperty:choose(val1|val2): <template type="{myproperty}"> <id>{anotherprop}</id> </template>| <template type="{myproperty}"> <id>{anotherprop}</id> </template>}||}

I assumed there was a way to use a complex condition (:cond:) but apparently this only applies to numbers. [0-9.-]+ Could we at least extend :cond: to apply =, !=, & / operators to strings as well?

[axunonb]

@krptodr: There is no LINQ implemented into Smart.Format selectors or format strings (if this was your question).

[axunonb]

@ericpyle: Yes, definitely. You could do this with an tailored extension similar to the conditional formatter. If you find a general approach, I'm happy to include the new extension to the repository.

[ericpyle]

@axunonb Thanks for the tip. This satisfies my needs for now:

Usage

{value:in(val1|val2|...): format | default}

Or in context of list:

{myList:list:{value:in(val1|val2|...): format | default}||}

        public class InFormatter : IFormatter
        {
            private string[] names = new[] { "in" };
            public string[] Names { get { return names; } set { this.names = value; } }

            public bool TryEvaluateFormat(IFormattingInfo formattingInfo)
            {
                var options = formattingInfo.FormatterOptions.Split('|');
                var formats = formattingInfo.Format.Split('|');
                if (formats.Count == 0)
                    return true;
                if (options.Contains(formattingInfo.CurrentValue))
                    formattingInfo.Write(formats.First(), formattingInfo.CurrentValue);
                else if (formats.Count == 2)
                    formattingInfo.Write(formats.Last(), formattingInfo.CurrentValue);
                return true;
            }
        }`

[axunonb]

Cool. Would it be possible to supply a unit test for the InFormatter?

[ericpyle]

I've been wondering if a regex value:matches(regex) formatter might be even better. It would even work with "val1|val2" and regex should have decent cross platform support

[axunonb]

How would you design it? RegEx groups in connection with lists?

[ericpyle]

@axunonb I wasn't thinking about handling lists directly. I'd do it like this (untested):

Syntax
{value:ismatch(regex): format | default}
Or in context of list:
{myList:list:{value:ismatch(regex): format | default}||}

Where regex can be a simple regex string like ^val1|val2|val3$ (match whole words)

        public class IsMatchFormatter : IFormatter
        {
            private string[] names = new[] { "ismatch" };
            public string[] Names { get { return names; } set { this.names = value; } }

            public bool TryEvaluateFormat(IFormattingInfo formattingInfo)
            {
                var regexStr = formattingInfo.FormatterOptions;
                var formats = formattingInfo.Format.Split('|');
                if (formats.Count == 0)
                    return true;
                var rgx = new Regex(regexStr);
                if (rgx.IsMatch(formattingInfo.CurrentValue))
                    formattingInfo.Write(formats.First(), formattingInfo.CurrentValue);
                else if (formats.Count == 2)
                    formattingInfo.Write(formats.Last(), formattingInfo.CurrentValue);
                return true;
            }
        }`

Thoughts?

[axunonb]

Agree this would be quite flexible (even more than your in extension idea) and also available under .NetStandard.
Maybe matches would be better than ismatch?
Would you post a PR?