2 // FileExtensionAttribute.cs
5 // Marek Safar <marek.safar@gmail.com>
6 // Pablo Ruiz García <pablo.ruiz@gmail.com>
8 // Copyright (C) 2013 Xamarin Inc (http://www.xamarin.com)
9 // Copyright (C) 2013 Pablo Ruiz García
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
35 using System.Globalization;
36 using System.Text.RegularExpressions;
38 namespace System.ComponentModel.DataAnnotations
40 // See: http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.fileextensionsattribute.aspx
42 [AttributeUsageAttribute (AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, AllowMultiple = false)]
43 public class FileExtensionsAttribute : DataTypeAttribute
45 private const string DefaultErrorMessage = "The {0} field only accepts files with the following extensions: {1}.";
46 private const string DefaultExtensions = "png,jpg,jpeg,gif";
48 public FileExtensionsAttribute ()
49 : base (DataType.Upload)
51 // XXX: There is no .ctor accepting Func<string> on DataTypeAttribute.. :?
52 base.ErrorMessage = DefaultErrorMessage;
53 this.Extensions = DefaultExtensions;
56 public string Extensions { get; set; }
58 private string[] GetExtensionList ()
60 return (Extensions ?? "").Split (',');
63 private string GetExtension (string filename)
65 var parts = filename.Split ('.');
66 return parts.Length > 0 ? parts [parts.Length - 1] : "";
69 public override string FormatErrorMessage (string name)
71 var extensions = GetExtensionList().Aggregate ((cur, next) => cur + ", " + next);
72 return string.Format (ErrorMessageString, name, extensions);
75 public override bool IsValid(object value)
82 var str = value as string;
83 var ext = GetExtension (str);
84 return GetExtensionList ().Any (x => string.Equals (x, ext, StringComparison.InvariantCultureIgnoreCase));