Question

Thanks for any thoughts.

while I am working my way through some custom validationAttributes, I have come across a problem which should be simple, but has me stumped.

An authorized user will have a UserProfile which includes a key to the site they work in. This site is a record set within a database. 1 field in this site record set is a regular expression which denotes what would be a valid format for a field in a completely separate table. The data entered into this other table will be common to all registered users, but a particular field relates to the ID format used at their institution.

Is there a clean way I can dynamically add a regular expression validator to a property?

Thank you as always.

Answer 1

This is what I came up with, but keen to know if there are better solutions:

Naming conventions are to allow automapper to flatten the model (each StudyCentre has a many to 1 relationship with the RecordSystem (some systems share the patient indexing system)

Mapper.CreateMap<StudyCentre, ParticipantRegistration.StudyCentreViewData>();

As a nested class within the ViewModel for an indidual TrialParticipant

public StudyCentreViewData ViewData { get; set; }
public class StudyCentreViewData
{
    public string Abbreviation { get; set; }
    public string RecordSystemName { get; set; }
    public string RecordSystemHospitalNoRegEx { get; set; }
    public string RecordSystemNotationDescription { get; set; }
    public IDictionary<string, object> HospitalNoRegEx()
    {
         return DynamicClientValidation.RegEx(errorMessage:String.Format("{0} must consist of {1}",
                                                                       RecordSystemName,
                                                                       RecordSystemNotationDescription),
                                              regExPattern: RecordSystemHospitalNoRegEx);
    }
}

The other properties (such as StudyCentre.Abbreviation are for the labels)
The function RegEx is simply:

public static class DynamicClientValidation
{
    public static IDictionary<string, object> RegEx(string errorMessage, string regExPattern)
    {
        var returnVal = new Dictionary<string, object>(3);
        returnVal.Add("data-val-regex", errorMessage);
        returnVal.Add("data-val-regex-pattern", regExPattern);
        returnVal.Add("data-val", "true");
        return returnVal;
    }
}

The Controller sets up the viewmodel like so:

model.ViewData = Mapper.Map<StudyCentre, ParticipantRegistration.StudyCentreViewData>(_studyCentre.GetCentreByUser(_currentUserName));

and in the view (LabelDetailsfor is a custom helper):

<div class="editor-label">
    @Html.LabelDetailsFor(model => model.HospitalID,Model.ViewData.Abbreviation + " ID", Model.ViewData.RecordSystemName) 
</div>
<div class="editor-field">
    @Html.TextBoxFor(model => model.HospitalID, Model.ViewData.HospitalNoRegEx())
    @Html.ValidationMessageFor(model => model.HospitalID)
 </div>