CODEWITHSUNDEEP
c#resources
bevacqua
bevacqua

Reputation: 48476

Format a Resource string into another one?

What would be the best way to accomplish something like this?

Suppose I have the following pair of Resource strings.

BadRequestParameter:            Potential bad request aborted before execution.
RequiredParameterConstraint:    {0} parameter requires a value. {1}

And suppose I want to set {1} on the second one, to the value of BadRequestParameter. I could easily do that using string.Format. But now suppose I have lots of Resource strings like the second one, all of which include some other Resource string in them.
What would be the best way to code this? Is using string.Format repeateadly in each case really all that I can do?

Update

I'll try to explain myself better. These are the resource strings I actually have:

BadRequestParameter     Potential bad request aborted before execution. 
EmptyVector             Vectorized requests require at least one element. {0}
OverflownVector         Vectorized requests can take at most one hundred elements. {0}
RequiredParamConstraint {0} parameter requires a value. {1}
SortMinMaxConstraint    {0} parameter value '{1}' does not allow Min or Max parameters in this query. {2}
SortRangeTypeConstraint Expected {0} parameter Type '{1}'. Actual: '{2}'. {3}
SortValueConstraint     {0} parameter does not allow '{1}' as a value in this query. {2}

I'd like to avoid writing the string in BadRequestParameter at the end of each of those lines. Therefore, I added a format at the end of those strings. The issue now is that I'd like to somehow auto-reference {x} to BadRequestParameter, in order to avoid having to make calls like

string.Format(Error.EmptyVector, Error.BadRequestParameter);

Upvotes: 4

Views: 1076

Answers (3)

Sergey Kalinichenko
Sergey Kalinichenko

Reputation: 726579

I have lots of Resource strings like the second one, all of which include some other Resource string in them.

Instead of storing pre-made format strings ready for use, you could store raw material for building real format strings, and add code to expand them pro grammatically before use. For example, you could store strings like this:

BadRequestParameter:            Potential bad request aborted before execution.
SupportNumber:                  (123)456-7890
CallTechSupport:                You need to call technical support at {SupportNumber}.
RequiredParameterConstraint:    {{0}} parameter requires a value. {BadRequestParameter} {CallTechSupport}

Of course passing these strings to string.Format as-is is not going to work. You need to parse these strings, for example with RegExps, and find all instances where you have a word between curly braces, instead of a number. You could then replace each word with its sequence number, and produce an array of parameters based on the names that you find between curly braces. In this case, you will get these two values (pseudocode):

formatString = "{{0}} parameter requires a value. {0} {1}";
// You replaced {BadRequestParameter} with {0} and {CallTechSupport} with {1}
parameters = {
    "Potential bad request aborted before execution."
,   "You need to call technical support at (123)456-7890."
};

Note: Of course, producing this array of parameters required recursion.

At this point, you can invoke string.Format to produce your final string:

var res = string.Format(formatString, parameters);

This returns the string that has resource strings pre-replaced for your callers:

"{0} parameter requires a value. Potential bad request aborted before execution. You need to call technical support at (123)456-7890."

The callers can now use this string for formatting, without bothering with other resource values.

Upvotes: 1

msarchet
msarchet

Reputation: 15242

IF you treat the argument indicators {#} as wild cards then why would it make sense for you to pre-fill them inside of your resource.

I see absolutely nothing wrong with

String.Format(RequiredParamterConstraint, "something", BadRequestParameter);

Upvotes: 0

Joel Martinez
Joel Martinez

Reputation: 47749

Yes :-) unless you want to make a helper method that is shorter, but that would really just be for convenience sake

public static string f(string format, params object[] p)
{
    return string.Format(format, p);
}

Upvotes: 0

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