How to globalize ASP.NET MVC views (decimal separators in particular)? - asp.net-mvc

I'm working with the NerdDinner sample application and arrived at the section which deals with the Virtual Earth map. The application stores some values for the longitude and latitude. Unfortunately on my system floating point numbers are stored with a comma as the decimal separator, not a dot like in the US. So if I have a latitude of 47.64 it's retrieved and displayed as 47,64. Because that value is passed in a function call to the Virtual Earth API it fails at that point (e.g. JavaScript API expects 47.64, -122.13, but gets 47,64, -122,13).
I need to make sure that the application always uses dots. In a WebForms app I would have a common class which overrides the System.Web.UI.Page.InitializeCulture() method and I would be inheriting my pages from that class.
I am not sure about how to do the same with MVC. Do I need a customized ViewPage or something? Is there an easy way to solve this? Examples?

Because setting <globalization/> to en-US did not help at all I decided to create a custom class which initializes the proper culture settings and make sure that all views which require this behavior are inherited from my custom class.
NerdDinnerViewPage.cs:
using System.Globalization;
using System.Threading;
using System.Web.Mvc;
namespace NerdDinner.Views
{
public class NerdDinnerViewPage<T> : ViewPage<T> where T : class
{
protected override void InitializeCulture()
{
base.InitializeCulture();
Thread.CurrentThread.CurrentCulture = Thread.CurrentThread.CurrentCulture.Clone() as CultureInfo;
if (Thread.CurrentThread.CurrentCulture != null)
{
Thread.CurrentThread.CurrentCulture.NumberFormat.CurrencyDecimalSeparator = ".";
Thread.CurrentThread.CurrentCulture.NumberFormat.NumberDecimalSeparator = ".";
}
}
}
}
Edit.aspx:
<%# Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="NerdDinner.Views.NerdDinnerViewPage<NerdDinner.Models.DinnerFormViewModel>" %>

I'm a Danish developer and was facing exactly the same problem. I found a working solution which has been kindly described by Kristof Neirynck on his dev blog:
Custom Model Binder
Best regards, Finn Vilsbaek

When you say
on my system floating point numbers are stored with a comma as the decimal separator
I assume you mean that they are formatted with a comma, floating point numbers are stored as float.
Whilst you can tackle the formatting issue by setting Cultures the "real" fix is to change the code. OK, it's not your code so maybe you don't want to do that on this occassion, but for general reference you need to ensure that when formatting floats or anything else you use the appropriate culture. In the case of fomatting a number for use by an API you would use the InvariantCulture.
I.e. use foo.ToString(CultureInfo.InvariantCulture) instead of foo.ToString() and likewise when using string.Format(...).
Edit I've just taken a look at the NerdDinner code and have realised that this error is in the Javascript not in C#, so my code above isn't going to help. I don't know if it is possible to format numbers in Javascript, but the real solution I think is to fix the model code to return a correctly formatted string.
Edit 2 I'd suggest you try the following:
In the SearchController.cs change the Latitude and Longitude in JsonDinner to strings. i.e.
public class JsonDinner {
public int DinnerID { get; set; }
public string Title { get; set; }
public string Latitude { get; set; }
public string Longitude { get; set; }
public string Description { get; set; }
public int RSVPCount { get; set; }
}
Then scroll down to the SearchByLocation method and change the Lat/Long lines to format the strings correctly for JavaScript:
Latitude = dinner.Latitude.ToString(CultureInfo.InvariantCulture),
Longitude = dinner.Longitude.ToString(CultureInfo.InvariantCulture),
This should mean that you do not need the fix you put in, and should fix your other question... where I will leave a comment. Hope this helps, I haven't fully tested is as I am not in your locale, but it certainly appears to work.

I'm using a simple quickfix in the TemplateEditor. My application is only using swedish (comma as decimal separator) so it's a single string.Replace but you could of course make it aware of multiple cultures.
In my Views/Shared/EditorTemplates/Decimal.ascx:

I fixed this on the JavaScript-side instead, making sure that what is passed in to the map-library is using points (.), and what is populated back into the text boxes are using commas (,). Obviously, this is not meant for localization, but a quick fix.
Map.js in callbackForLocation:
//If we've found exactly one place, that's our address.
if (points.length === 1) {
$("#Latitude").val(points[0].Latitude.toString().replace('.', ','));
$("#Longitude").val(points[0].Longitude.toString().replace('.', ','));
}
Map.ascx in the jquery-ready():
var latitude = <%=Model.Latitude.ToString().Replace(',', '.')%>;
var longitude = <%=Model.Longitude.ToString().Replace(',', '.')%>;

Related

MVC set Data annotations attributes in code

Is it possible to set range (or any other model DataAnnotations attributes) in code and keep all the DataAnnotations behaviour?
i.e. I have a decimal model that I want to set its minimum value in code (on page load for example) in a way I could keep using the ValidationMessageFor ?
my current "static" model
[Required]
[DisplayName("Price")]
[RegularExpression(#"[0-9]+(\.[0-9][0-9]?)?$", ErrorMessage = "Invalid price format")]
public decimal MinimumPrice { get; set; }
Thanks!
No, DataAnnotations are compiled into the code at compile time and cannot be changed at runtime.
If you insist on using DataAnnotations, then there really is no other choice.
If you are willing to do something else, then you have a number of other options. You could create your own Attribute that would read values from the variable of your choice (though you can't pass a variable to it).
Or you could use FluentValidation.
You can achieve some of what you want using Fluent API:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<SomeClass>()
.Property(x => x.MinimumPrice )
.IsRequired()
.HasColumnType("decimal")
.HasPrecision(18, 2);
// default vals for decimal type. 18 = precision = how many digits in
// total. 2 = scale = digits after decimal
}
For some things it's better to use fluent configuration and others to use annotations.
Further reading.

change validate message in data annotation

my object has field with data type int. when i put in html form in this textbox letter not number the validator say- The field must be a number. how can i change this messages like this
[Required(ErrorMessage = "Введите название")]
[DisplayName("Название")]
public int age { get; set; }
I haven't found a clean way to achieve this using Data Annotations. One way would be to write a custom model binder but this seems like a lot of work to do for such a simple task.
Another way to achieve this is to add an App_GlobalResources folder to your ASP.NET application. Add a resource file called Messages.resx containing a PropertyValueRequired string resource.
PropertyValueRequired = "Some custom error message"
In your Application_Start register the resource class key:
protected void Application_Start()
{
RegisterRoutes(RouteTable.Routes);
DefaultModelBinder.ResourceClassKey = "Messages";
}
Note that ASP.NET MVC 2 uses the PropertyValueInvalid instead of PropertyValueRequired resource key.
IMO using Data Annotations to perform validation logic is limited (maybe in .NET 4 this will change). If you want to have full control over the validation logic I would recommend you using a validation library such as Fluent Validation or xVal.
I ran into the same problem and worked around it by specifying a RegularExpression that only allows positive natural numbers.
[Required(ErrorMessage = "Введите название")]
[DisplayName("Название")]
[RegularExpression(#"^[0-9]+$", ErrorMessage = "Поле возраст не является числом")]
public int age { get; set; }
Not sure if there are any downfalls to this solution. It seems to work fine for me.
PS: If you don't want to allow leading zeroes use "^[1-9]+[0-9]*$".
In retrospect: I have to admit though it's a bit weird to add a regular expression to an integer.

Creating an ActionLink with a DateTime in the query string in ASP.NET MVC

I have a search form with a DateTime search criterion, plus some other criteria:
<form method="get" action="/app/search">
<input type="text" value="13/01/2010" name="BeginDate"/>
<input type="text" value="blah" name="SomeOtherCriterion"/>
<form>
So I have a Search controller with a default Action (let's call it Index) and with a SearchCriteria parameter.
public class SearchController
{
public ActionResult Index(SearchCriteria searchCriteria) {//blah }
}
public class SearchCriteria
{
public DateTime BeginDate {get; set;}
public string SomeOtherCriterion {get; set;}
}
Now if I want to create an ActionLink, passing in a SearchCriteria value, thus:
Html.ActionLink("Search", "Index", searchCriteria)
I get the BeginDate query string parameter in US format. Looking on Google and poking around in System.Web.Routing using Reflector it seems to be because it uses the InvariantCulture, so there's nothing I can do about it.
It seems like noone has asked this question before so I guess I'm doing something very stupid.... Please help!
EDIT: Pass in SearchCriteria to ActionLink rather than anonymous object to show why I can't just do the custom ToString() myself.
Given that the framework appears to be hard-coded to handle this piece of data using InvariantCulture, I don't think there's much you can do to make it work transparently.
There is one ugly option - download the MVC source and rip out the code for all the offending classes from Route down to ParsedRoute to create your own RouteBase implementation that does what you need.
If I absolutely had to keep the DateTime declaration on the SearchCriteria class, then that's the route (sorry for the pun) I would choose.
However, a far easier solution would be to change your SearchCriteria class to use a slightly different declaration for the DateTime field, based on a type like this:
public class MyDateTime
{
public DateTime Value { get; set; }
//for passing MyDateTime in place of a DateTime without casting
public static implicit operator DateTime(MyDateTime instance) { return instance.Value; }
//so you can assign a MyDateTime from a DateTime without a cast
//- e.g. MyDateTime dt = DateTime.Now
public static implicit operator MyDateTime(DateTime instance) { return new MyDateTime() { Value = instance }; }
//override ToString so that CultureInfo.CurrentCulture is used correctly.
public override string ToString()
{
return Value.ToString(CultureInfo.CurrentUICulture);
}
}
In theory you should be able to roll out this change without too much fuss.
The big work could be if you have a lot of code that uses members (e.g. .Days etc) of the DateTime instance in SearchCriteria: you either have to reproduce those members on MyDateTime, wrapping around the inner DateTime Value or change all the code to use .Value.Member.
To avoid issues related to Regional Settings and "Culture",
I treat date and time as separate unbound fields and then
assemble them into DateTime in my Controller.
Example:
Year [ ] Month [ ] Day [ ]
I always present separate textboxes for year, month, and day, in that order so that there can be no confusion between U.S. format (month/day/year) and more or less the rest of the world's format (day/month/year).
Can you provide a formatted date in your ActionLink? Try this:
Html.ActionLink("Search",
"Index",
new {BeginDate =
DateTime.Now.ToString("d", new CultureInfo("pt-BR");})
Of course this changes BeginDate to a string instead of a DateTime... but maybe that will work for you?
We use ISO ("s" in a format string -- YYYY-MM-DDTHH:MM:SS) format for this. It works correctly, and JavaScript can handle it as well.
Perhaps you could use a Model Binder to format and parse the date? Just re-read the article and noticed that it does not format the date...Probably not going to work out. I'll leave the answer though in case it provides any unintentional inspiration :)
poking around in System.Web.Routing using Reflector it
seems to be because it uses the
InvariantCulture
Are you realy shure about this? The parts of Modelbinding and UrlBuilding I checked used CurrentCulture. Can you check what happens if you set the CurrentCulture before rendering the link?
Get the ASP.NET MVC 1.0 book written by Scott Hanselman, Scott Guthrie, Phil Haack, and Rob Conery. They actually do this exact scenario in the book. They use a specific route. I am looking at it right now on page 216.
They do it by breaking up day, month, and year. Then it is your responsibility to use those values as they come back.

How do you handle reporting filters in ASP.NET MVC?

For a given report, the user will want to have multiple filtering options. This isn't bad when the options are enumerations, and other 'static' data types, however things can get silly fast when you need a select list that is populated by fields stored in a table in the backend.
How do you handle this scenario? I find myself constantly reshaping the View data to accommodate the additional filter fields, but it really is starting to be a bit much tracking not only the selected options, but also the options themselves...
is there not a better way?
I’m currently building out a new reporting section for one of our products at work and am dealing with this same issue. The solution I’ve come up with so far, though it hasn’t been implemented yet so this is still a work in progress, is along the lines of this.
There will be a class that will represent a report filter which will contain some basic info such as the label text and a list of option values.
public enum DisplayStyle
{
DropDown,
ListBox,
RadioList,
CheckList,
TextBox
}
public class FilterOption
{
public string Name { get; set; }
public string Value { get; set; }
public bool Selected { get; set; }
}
public class ReportFilter
{
public string Title { get; set; }
public DisplayStyle Style { get; set; }
public List<FilterOption> Options { get; set; }
}
And then my model will contain a list of these option classes that will be generated based on each report’s needs. I also have a base report class that each report will inherit from so that way I can handle building out the option lists on a per report basis and use one view to handle them all.
public class ReportModel
{
public string Name { get; set; }
public List<ReportFilter> Filters { get; set; }
public DateTime StartDate { get; set; }
public DateTime EndDate { get; set; }
}
Then inside my view(s) I’ll have some helper methods that will take in those option classes and build out the actual controls for me.
public static string ReportFilter(this HtmlHelper htmlHelper, DisplayStyle displayStyle, FilterOption filterOption)
{
switch (displayStyle)
{
case DisplayStyle.TextBox:
return string.Format("<input type=\"text\"{0}>", filterOption.Selected ? (" value=\"" + filterOption.Value + "\"") : string.Empty);
break;
...
}
}
My route would look like this
Reports/{reportID}/start/{startDate}/end/{endDate}/{*pathInfo}
All reports have a start and end date and then optional filters. The catchall parameter will have lists of filter values in the form of “Customer/1,4,7/Program/45,783”. So it’ll be like a key/value pair in list form. Then when the controller loads it’ll parse out those values into something more meaningful.
public static Dictionary<string, string> RouteParams(string pathInfo)
{
if (string.IsNullOrEmpty(pathInfo))
{
return new Dictionary<string, string>();
}
var values = new Dictionary<string, string>();
// split out params and add to the dictionary object
return values;
}
Then it will pass them off to the report class and validate them to make sure they’re correct for that report. Then when the options are loaded for that report anything that’s been set in the URL will be set to Selected in the ReportOption class so their state can be maintained. Then the filter list and other report data will be added to the model.
For my setup some filters will change when another filters selection changes so there will be some AJAX in here to post the data and get the updated filter options. The drilldown will work sort of like the search options at amazon or newegg when you narrow your search criteria.
I hope that all makes sense to someone beside me. And if anyone has some input on improving it I’d be happy to hear it.
You could go and retrieve the data asynchronously on the screen using jQuery and JsonResults from your MVC application, this is how we populate all of our lists and searches in our applications. I have an example of how it is done here.
This way the view data is loaded on demand, if they don't use the extra filters then they don't have to get the view data and if one selection relates to another then it's clear which set of data you need to retrieve.
Another option, though I don't like this one as much but jQuery solution may not suit you, is to have your model object for your view contain all the view data so that all you need to do is set the single model object and all the lists are loaded directly and strongly typed. This will simplify the view and the back end code because it will be more clear that for this view the only thing you need is a complete version of this model object.
For example if you had two lists for combo boxes then your model might look like:
public class MyViewMode
{
public int MyProperty { get; set; }
public string SomeString { get; set; }
List<string> ComboListA { get; set; }
List<string> ComboListB { get; set; }
}
Hope that makes sense, if not please comment and I'll expand on it.
Ad-hoc filtering on reports is indeed a tricky issue especially when you want to show a custom user interface control based on the data type, do validation, make some filters to be dependent on one another and others not, etc.
One thing I think that is worth considering is the old "build vs buy" issue here. There are specialized tools out there for ad-hoc reporting that do provide a UI for ad-hoc filters help with this such as the usual suspects Crystal Reports, Microsoft's Reporting Services, or our product ActiveReports Server. In ActiveReports Server we support cascading prompts (where available values in prompts depend on one another) and make it easy for anyone, even non-technical business users to modify the prompts (assuming they have permissions obviously). More information about using prompts in ActiveReports Server is here. ActiveReports Server is also, all managed .NET code, and provides ASP.NET controls and web services that allows you to integrate it into your web apps.
Scott Willeke
Product Manager - ActiveReports Server
GrapeCity inc.

Formatting data in a Fitnesse RowFixture

I've got a Fitnesse RowFixture that returns a list of business objects. The object has a field which is a float representing a percentage between 0 and 1. The consumer of the business object will be a web page or report that comes from a designer, so the formatting of the percentage will be up to the designer rather than the business object.
It would be nicer if the page could emulate the designer when converting the number to a percentage, i.e. instead of displaying 0.5, it should display 50%. But I'd rather not pollute the business object with the display code. Is there a way to specify a format string in the RowFixture?
You certainly don't want to modify your Business Logic just to make your tests look better. Good news however, there is a way to accomplish this that is not difficult, but not as easy as passing in a format specifier.
Try to think of your Fit Fixture as a service boundary between FitNesse and your application code. You want to define a contract that doesn't necessarily have to change if the implementation details of your SUT (System Under Test) change.
Lets look at a simplified version of your Business Object:
public class BusinessObject
{
public float Percent { get; private set; }
}
Becuase of the way that a RowFixture works we need to define a simple object that will work as the contract. Ordinarily we would use an interface, but that isn't going to serve our purpose here so a simple DTO (Data Transfer Object) will suffice.
Something Like This:
public class ReturnRowDTO
{
public String Percent { get; set; }
}
Now we can define a RowFixture that will return a list of our custom DTO objects. We also need to create a way to convert BusinessObjects to ReturnRowDTOs. We end up with a Fixture that looks something like this.
public class ExampleRowFixture: fit.RowFixture
{
private ISomeService _someService;
public override object[] Query()
{
BusinessObject[] list = _someService.GetBusinessObjects();
return Array.ConvertAll(list, new Converter<BusinessObject, ReturnRowDTO>(ConvertBusinessObjectToDTO));
}
public override Type GetTargetClass()
{
return typeof (ReturnRowDTO);
}
public ReturnRowDTO ConvertBusinessObjectToDTO(BusinessObject businessObject)
{
return new ReturnRowDTO() {Percent = businessObject.Percent.ToString("%")};
}
}
You can now change your underlying BusinessObjects around without breaking your actual Fit Tests. Hope this helps.
I'm not sure what the "polution" is. Either the requirement is that your Business Object returns a value expressed as a percentage, in which case your business object should offer that -OR- you are testing the true value of the response as float, which you have now.
Trying to get fitnesse to massage the value for readability seems a bit odd.

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