Localizing Microsoft ReportViewer

Published on May 5th, 2012

How-to.NET

Microsoft ReportViewer Control can be localized by implementing the three IReportViewerMessages interfaces. However, the documentation of these interfaces lacks the original string values, which in turn makes it difficult to provide a proper translation. In this blog, a complete listing of these values and a Dutch implementation of IReportViewerMessages are presented.

Microsoft ReportViewer

Microsoft ReportViewer is a .NET control that can be used in both Windows and Web applications to render Microsoft Reports. Unlike the name suggests, the ReportViewer does a whole lot more than just view reports. The control is capable of loading (remote) RDL files, executing its contents and rendering the end result in various formats (including HTML, Excel, Word, PDF). Once rendered, the user can interact with the control in order to pass report parameters, navigate through multipage reports and more.

ReportViewer localized to the Dutch culture and language.

In my current project, we embedded ReportViewer inside an ASP MVC web application. As the audience of the application is Dutch, all content, including the ReportViewer, must be localized to the Dutch culture. Unfortunately, the language packs available for ReportViewer do not include Dutch, so I had to come up with an alternative solution.

The Good

Fortunately, Microsoft included a mechanism in the ReportViewer control which allows developers to override the default messages. This is achieved by implementing various interfaces in the parent application that utilizes ReportViewer and then passing these custom implementations to the ReportViewer control.

More specifically, these interfaces are IReportViewerMessages, IReportViewerMessages2 and IReportViewerMessages3, which reside in the Microsoft.Reporting.WebForms namespace (or WinForms if you’re using that). These interfaces are essentially just collections of read-only string properties with static hardcoded values.

The Bad

While Microsoft was graceful enough to document these interfaces, their documentation lacks the original values of these string properties. As a result, anyone who wants to create a meaningful translation of these properties must deduce the meaning from the property’s name and description, rather than the original value. This can be quite challenging when faced with cryptic names such as ParameterAreaButtonToolTip, NullValueText or ClientPrintControlLoadFailed.

The Ugly

While the lack of original values is a nuisance, it is in no means a showstopper. Poor translations can result in the user being faced with messages that seem out of place, but the application itself will remain functional. Or so I thought:

Input string was not in a correct format.

First attempt at localizing ReportViewer results in a FormatException

Most .NET developers will be familiar with this exception as it is the result of String.Format being invoked with a format string which does not match the expected objects to format. In other words, one or more of the strings which I am translating use the composite formatting feature. Without the original English values of these strings, one is left to guess which of these strings must contain formatting placeholders.

The Solution

To overcome this problem, I decompiled the ReportViewer assembly and extracted the original string values of these properties. Below is a version of my Dutch implementation of the IReportViewerMessages interfaces. Each property includes the original text in English, so you could use it as a template for your own translations.

DutchReportViewerMessages.cs

1using System;
2using System.Globalization;
3using Microsoft.Reporting.WebForms;
4 
5namespace InfoSupport.SomeApplication
6{
7    public class DutchReportViewerMessages : IReportViewerMessages, IReportViewerMessages2, IReportViewerMessages3
8    {
9        #region IReportViewerMessages Members
10 
11        // English value: Back to Parent Report
12        public string BackButtonToolTip
13        {
14            get { return "Terug naar het vorige rapport"; }
15        }
16 
17        // English value: Change Credentials
18        public string ChangeCredentialsText
19        {
20            get { return "Wijzig Rechten"; }
21        }
22 
23        // English value: Change Credentials
24        public string ChangeCredentialsToolTip
25        {
26            get { return "Wijzig Rechten"; }
27        }
28 
29        // English value: Current Page
30        public string CurrentPageTextBoxToolTip
31        {
32            get { return "Huidige Pagina"; }
33        }
34 
35        // English value: Document Map
36        public string DocumentMap
37        {
38            get { return "Document Map"; }
39        }
40 
41        // English value: Show / Hide Document Map
42        public string DocumentMapButtonToolTip
43        {
44            get { return "Toon / Verberg Document Map"; }
45        }
46 
47        // English value: Export
48        public string ExportButtonText
49        {
50            get { return "Exporteer"; }
51        }
52 
53        // English value: Export
54        public string ExportButtonToolTip
55        {
56            get { return "Exporteer"; }
57        }
58 
59        // English value: Export Formats
60        public string ExportFormatsToolTip
61        {
62            get { return "Exporteer Formaten"; }
63        }
64 
65        // English value: False
66        public string FalseValueText
67        {
68            get { return "Onwaar"; }
69        }
70 
71        // English value: Find
72        public string FindButtonText
73        {
74            get { return "Zoek"; }
75        }
76 
77        // English value: Find
78        public string FindButtonToolTip
79        {
80            get { return "Zoek"; }
81        }
82 
83        // English value: Next
84        public string FindNextButtonText
85        {
86            get { return "Volgende"; }
87        }
88 
89        // English value: Find Next
90        public string FindNextButtonToolTip
91        {
92            get { return "Volgend Resultaat"; }
93        }
94 
95        // English value: First Page
96        public string FirstPageButtonToolTip
97        {
98            get { return "Eerste Pagina"; }
99        }
100 
101        // English value: Enter a valid page number
102        public string InvalidPageNumber
103        {
104            get { return "Voer een geldig paginanummer in"; }
105        }
106 
107        // English value: Last Page
108        public string LastPageButtonToolTip
109        {
110            get { return "Laatste Pagina"; }
111        }
112 
113        // English value: Next Page
114        public string NextPageButtonToolTip
115        {
116            get { return "Volgende Pagina"; }
117        }
118 
119        // English value: The entire report has been searched.
120        public string NoMoreMatches
121        {
122            get { return "Het volledige rapport is doorzocht."; }
123        }
124 
125        // English value: NULL
126        public string NullCheckBoxText
127        {
128            get { return "Geen waarde"; }
129        }
130 
131        // English value: Null
132        public string NullValueText
133        {
134            get { return "Geen waarde"; }
135        }
136 
137        // English value: of
138        public string PageOf
139        {
140            get { return "van"; }
141        }
142 
143        // English value: Show / Hide Parameters
144        public string ParameterAreaButtonToolTip
145        {
146            get { return "Toon / Verberg Parameters"; }
147        }
148 
149        // English value: Password:
150        public string PasswordPrompt
151        {
152            get { return "Wachtwoord:"; }
153        }
154 
155        // English value: Previous Page
156        public string PreviousPageButtonToolTip
157        {
158            get { return "Vorige Pagina"; }
159        }
160 
161        // English value: Print
162        public string PrintButtonToolTip
163        {
164            get { return "Afdrukken"; }
165        }
166 
167        // English value: Loading...
168        public string ProgressText
169        {
170            get { return "Verwerken..."; }
171        }
172 
173        // English value: Refresh
174        public string RefreshButtonToolTip
175        {
176            get { return "Vernieuwen"; }
177        }
178 
179        // English value: Find Text in Report
180        public string SearchTextBoxToolTip
181        {
182            get { return "Zoek naar tekst binnen het rapport"; }
183        }
184 
185        // English value: <Select a Value>
186        public string SelectAValue
187        {
188            get { return "<Selecteer een waarde>"; }
189        }
190 
191        // English value: (Select All)
192        public string SelectAll
193        {
194            get { return "(Selecteer alles)"; }
195        }
196 
197        // English value: Select a format
198        public string SelectFormat
199        {
200            get { return "Selecteer een formaat"; }
201        }
202 
203        // English value: The search text was not found.
204        public string TextNotFound
205        {
206            get { return "De zoektekst is niet gevonden."; }
207        }
208 
209        // English value: Today is {0}
210        public string TodayIs
211        {
212            get { return "Vandaag is {0}"; }
213        }
214 
215        // English value: True
216        public string TrueValueText
217        {
218            get { return "Waar"; }
219        }
220 
221        // English value: Log In Name:
222        public string UserNamePrompt
223        {
224            get { return "Gebruikersnaam:"; }
225        }
226 
227        // English value: View Report
228        public string ViewReportButtonText
229        {
230            get { return "Toon Rapport"; }
231        }
232 
233        // English value: Zoom
234        public string ZoomControlToolTip
235        {
236            get { return "Zoom"; }
237        }
238 
239        // English value: Page Width
240        public string ZoomToPageWidth
241        {
242            get { return "Paginabreedte"; }
243        }
244 
245        // English value: Whole Page
246        public string ZoomToWholePage
247        {
248            get { return "Volledige pagina"; }
249        }
250 
251        #endregion
252 
253        #region IReportViewerMessages2 Members
254 
255        // English value: Your browser does not support scripts or has been configured not to allow scripts.
256        public string ClientNoScript
257        {
258            get { return "Uw browser ondersteunt geen JavaScript of deze ondersteuning is uitgeschakeld."; }
259        }
260 
261        // English value: Unable to load client print control.
262        public string ClientPrintControlLoadFailed
263        {
264            get { return "Het laden van het client print control is niet gelukt."; }
265        }
266 
267        // English value: One or more data sources is missing a user name.
268        public string CredentialMissingUserNameError(string dataSourcePrompt)
269        {
270            return "Een of meerdere databronnen missen een gebruikersnaam.";
271        }
272 
273        // English value is different for each Rendering Extension. See comment behind each type.
274        public string GetLocalizedNameForRenderingExtension(string format)
275        {
276            switch (format)
277            {
278                case "XML"   : return "XML databestand (.xml)";  // XML file with report data
279                case "CSV"   : return "CSV databestand (.csv)";  // CSV (comma delimited)
280                case "PDF"   : return "PDF document (.pdf)";     // PDF
281                case "MHTML" : return "Webarchief (.mhtml)";     // MHTML (web archive)
282                case "EXCEL" : return "Excel rekenblad (.xls)";  // Excel
283                case "IMAGE" : return "Afbeelding (.tif)";       // TIFF file
284                case "WORD"  : return "Word document (.doc)";    // Word
285                default      : return null;
286            }
287        }
288 
289        // English value: Select a value
290        public string ParameterDropDownToolTip
291        {
292            get { return "Selecteer een waarde"; }
293        }
294 
295        // English value: Please select a value for the parameter '{0}'.
296        public string ParameterMissingSelectionError(string parameterPrompt)
297        {
298            return String.Format(CultureInfo.CurrentCulture, "Selecteer een waarde voor de parameter '{0}'", parameterPrompt);
299        }
300 
301        // English value: Please enter a value for the parameter '{0}'. The parameter cannot be blank.
302        public string ParameterMissingValueError(string parameterPrompt)
303        {
304            return String.Format(CultureInfo.CurrentCulture, "Selecteer een waarde voor de parameter '{0}'. De parameter mag niet leeg zijn.", parameterPrompt);
305        }
306 
307        #endregion
308 
309        #region IReportViewerMessages3 Members
310 
311        // English value: Loading...
312        public string CalendarLoading
313        {
314            get { return "Verwerken..."; }
315        }
316 
317        // English value: Cancel
318        public string CancelLinkText
319        {
320            get { return "Annuleer"; }
321        }
322 
323        // English value: pageCount if PageCountMode.Actual, else pageCount suffixed with a ?
324        public string TotalPages(int pageCount, PageCountMode pageCountMode)
325        {
326            return string.Format(CultureInfo.CurrentCulture, "{0}{1}", pageCount, pageCountMode == PageCountMode.Estimate ? "~" : String.Empty);
327        }
328 
329        #endregion
330    }
331}

Naturally, it would be irresponsible of me to paste code without some matching unit tests:

DutchReportViewerMessagesTests.cs

1using System;
2using Microsoft.VisualStudio.TestTools.UnitTesting;
3using InfoSupport.SomeApplication;
4 
5namespace InfoSupport.SomeApplication.Tests
6{
7    [TestClass]
8    public class DutchReportViewerMessagesTests
9    {
10        [TestMethod]
11        public void TranslatedStringsTests()
12        {
13            var m = new DutchReportViewerMessages();
14            Assert.IsTrue(!String.IsNullOrEmpty(m.BackButtonToolTip));
15            Assert.IsTrue(!String.IsNullOrEmpty(m.CalendarLoading));
16            Assert.IsTrue(!String.IsNullOrEmpty(m.CancelLinkText));
17            Assert.IsTrue(!String.IsNullOrEmpty(m.ChangeCredentialsText));
18            Assert.IsTrue(!String.IsNullOrEmpty(m.ChangeCredentialsToolTip));
19            Assert.IsTrue(!String.IsNullOrEmpty(m.ClientNoScript));
20            Assert.IsTrue(!String.IsNullOrEmpty(m.ClientPrintControlLoadFailed));
21            Assert.IsTrue(!String.IsNullOrEmpty(m.CredentialMissingUserNameError(null)));
22            Assert.IsTrue(!String.IsNullOrEmpty(m.CurrentPageTextBoxToolTip));
23            Assert.IsTrue(!String.IsNullOrEmpty(m.DocumentMap));
24            Assert.IsTrue(!String.IsNullOrEmpty(m.DocumentMapButtonToolTip));
25            Assert.IsTrue(!String.IsNullOrEmpty(m.ExportButtonText));
26            Assert.IsTrue(!String.IsNullOrEmpty(m.ExportButtonToolTip));
27            Assert.IsTrue(!String.IsNullOrEmpty(m.ExportFormatsToolTip));
28            Assert.IsTrue(!String.IsNullOrEmpty(m.FalseValueText));
29            Assert.IsTrue(!String.IsNullOrEmpty(m.FindButtonText));
30            Assert.IsTrue(!String.IsNullOrEmpty(m.FindButtonToolTip));
31            Assert.IsTrue(!String.IsNullOrEmpty(m.FindNextButtonText));
32            Assert.IsTrue(!String.IsNullOrEmpty(m.FindNextButtonToolTip));
33            Assert.IsTrue(!String.IsNullOrEmpty(m.FirstPageButtonToolTip));
34            Assert.IsTrue(!String.IsNullOrEmpty(m.InvalidPageNumber));
35            Assert.IsTrue(!String.IsNullOrEmpty(m.LastPageButtonToolTip));
36            Assert.IsTrue(!String.IsNullOrEmpty(m.NextPageButtonToolTip));
37            Assert.IsTrue(!String.IsNullOrEmpty(m.NoMoreMatches));
38            Assert.IsTrue(!String.IsNullOrEmpty(m.NullCheckBoxText));
39            Assert.IsTrue(!String.IsNullOrEmpty(m.NullValueText));
40            Assert.IsTrue(!String.IsNullOrEmpty(m.PageOf));
41            Assert.IsTrue(!String.IsNullOrEmpty(m.ParameterAreaButtonToolTip));
42            Assert.IsTrue(!String.IsNullOrEmpty(m.ParameterDropDownToolTip));
43            Assert.IsTrue(!String.IsNullOrEmpty(m.ParameterMissingSelectionError(String.Empty)));
44            Assert.IsTrue(!String.IsNullOrEmpty(m.ParameterMissingValueError(String.Empty)));
45            Assert.IsTrue(!String.IsNullOrEmpty(m.PasswordPrompt));
46            Assert.IsTrue(!String.IsNullOrEmpty(m.PreviousPageButtonToolTip));
47            Assert.IsTrue(!String.IsNullOrEmpty(m.PrintButtonToolTip));
48            Assert.IsTrue(!String.IsNullOrEmpty(m.ProgressText));
49            Assert.IsTrue(!String.IsNullOrEmpty(m.RefreshButtonToolTip));
50            Assert.IsTrue(!String.IsNullOrEmpty(m.SearchTextBoxToolTip));
51            Assert.IsTrue(!String.IsNullOrEmpty(m.SelectAll));
52            Assert.IsTrue(!String.IsNullOrEmpty(m.SelectAValue));
53            Assert.IsTrue(!String.IsNullOrEmpty(m.SelectFormat));
54            Assert.IsTrue(!String.IsNullOrEmpty(m.TextNotFound));
55            Assert.IsTrue(!String.IsNullOrEmpty(m.TodayIs));
56            Assert.IsTrue(!String.IsNullOrEmpty(m.TrueValueText));
57            Assert.IsTrue(!String.IsNullOrEmpty(m.UserNamePrompt));
58            Assert.IsTrue(!String.IsNullOrEmpty(m.ViewReportButtonText));
59            Assert.IsTrue(!String.IsNullOrEmpty(m.ZoomControlToolTip));
60            Assert.IsTrue(!String.IsNullOrEmpty(m.ZoomToPageWidth));
61            Assert.IsTrue(!String.IsNullOrEmpty(m.ZoomToWholePage));
62        }
63 
64        [TestMethod]
65        public void FormattableStringsTest()
66        {
67            var m = new DutchReportViewerMessages();
68            var parameter = "abc123";
69            Assert.IsTrue(m.ParameterMissingSelectionError(parameter).Contains(parameter));
70            Assert.IsTrue(m.ParameterMissingValueError(parameter).Contains(parameter));
71            Assert.IsTrue(String.Format(m.TodayIs, parameter).Contains(parameter));
72        }
73 
74        [TestMethod]
75        public void GetLocalizedNameForRenderingExtensionTest()
76        {
77            var m = new DutchReportViewerMessages();
78            string[] knownExtensions = { "XML", "CSV", "PDF", "MHTML", "EXCEL", "IMAGE", "WORD"};
79            foreach (var ext in knownExtensions)
80                Assert.IsTrue(!String.IsNullOrEmpty(m.GetLocalizedNameForRenderingExtension(ext)));
81        }
82 
83        [TestMethod]
84        public void GetLocalizedNameForRenderingExtensionTest_UnknownExtensionReturnsNull()
85        {
86            var m = new DutchReportViewerMessages();
87            string[] unknownExtensions = { "DOCX", "PNG", "JPG", "JPEG" };
88            foreach (var ext in unknownExtensions)
89                Assert.IsNull(m.GetLocalizedNameForRenderingExtension(ext));
90        }
91 
92        [TestMethod]
93        public void TotalPagesTest()
94        {
95            var m = new DutchReportViewerMessages();
96            Assert.AreEqual("10",  m.TotalPages(10, Microsoft.Reporting.WebForms.PageCountMode.Actual));
97            Assert.AreEqual("10~", m.TotalPages(10, Microsoft.Reporting.WebForms.PageCountMode.Estimate));
98        }
99    }
100}

Additionally, below is a table of all properties with their respective English and Dutch translation. Note that this table does not include the methods that are part of the interfaces.

IREPORTVIEWERMESSAGES

PROPERTY NAME	ORIGINAL ENGLISH VALUE	DUTCH TRANSLATION
BackButtonToolTip	Back to Parent Report	Terug naar het vorige rapport
ChangeCredentialsText	Change Credentials	Wijzig Rechten
ChangeCredentialsToolTip	Change Credentials	Wijzig Rechten
CurrentPageTextBoxToolTip	Current Page	Huidige Pagina
DocumentMap	Document Map	Document Map
DocumentMapButtonToolTip	Show / Hide Document Map	Toon / Verberg Document Map
ExportButtonText	Export	Exporteer
ExportButtonToolTip	Export	Exporteer
ExportFormatsToolTip	Export Formats	Exporteer Formaten
FalseValueText	False	Onwaar
FindButtonText	Find	Zoek
FindButtonToolTip	Find	Zoek
FindNextButtonText	Next	Volgende
FindNextButtonToolTip	Find Next	Volgend Resultaat
FirstPageButtonToolTip	First Page	Eerste Pagina
InvalidPageNumber	Enter a valid page number	Voer een geldig paginanummer in
LastPageButtonToolTip	Last Page	Laatste Pagina
NextPageButtonToolTip	Next Page	Volgende Pagina
NoMoreMatches	The entire report has been searched.	Het volledige rapport is doorzocht.
NullCheckBoxText	NULL	Geen waarde
NullValueText	Null	Geen waarde
PageOf	of	van
ParameterAreaButtonToolTip	Show / Hide Parameters	Toon / Verberg Parameters
PasswordPrompt	Password:	Wachtwoord:
PreviousPageButtonToolTip	Previous Page	Vorige Pagina
PrintButtonToolTip	Print	Afdrukken
ProgressText	Loading...	Verwerken...
RefreshButtonToolTip	Refresh	Vernieuwen
SearchTextBoxToolTip	Find Text in Report	Zoek naar tekst binnen het rapport
SelectAValue	<Select a Value>	<Selecteer een waarde>
SelectAll	(Select All)	(Selecteer alles)
SelectFormat	Select a format	Selecteer een formaat
TextNotFound	The search text was not found.	De zoektekst is niet gevonden.
TodayIs	Today is 0	Vandaag is 0
TrueValueText	True	Waar
UserNamePrompt	Log In Name:	Gebruikersnaam:
View Report	ViewReportButtonText	Toon Rapport
ZoomControlToolTip	Zoom	Zoom
ZoomToPageWidth	Page Width	Paginabreedte
ZoomToWholePage	Whole Page	Volledige pagina

IREPORTVIEWERMESSAGES2

PROPERTY NAME	ORIGINAL ENGLISH VALUE	DUTCH TRANSLATION
ClientNoScript	Your browser does not support scripts or has been configured not to allow scripts.	Uw browser ondersteunt geen JavaScript of deze ondersteuning is uitgeschakeld.
ClientPrintControlLoadFailed	Unable to load client print control.	Het laden van het client print control is niet gelukt.
ParameterDropDownToolTip	Select a value	Selecteer een waarde

IREPORTVIEWERMESSAGES3

PROPERTY NAME	ORIGINAL ENGLISH VALUE	DUTCH TRANSLATION
CalendarLoading	Loading...	Verwerken...
CancelLinkText	Cancel	Annuleer

Additional notes

Returning null will make ReportViewer default back to the original value. Use this for string properties or methods you do not wish to translate.
Getting ReportViewer to pick up your custom implementation requires a change in your application’s web.config or app.config. Add <add key="ReportViewerMessages" value="MyClass, MyAssembly" /> to your appSettings and substitute MyClass and MyAssembly with the name of your implementing class and the assembly it resides in.

Summary

Microsoft ReportViewer Control can be localized by implementing the three IReportViewerMessages interfaces. However, the documentation of these interfaces lack the original string values, which in turn makes it difficult to provide a proper translation. In this blog, a complete listing of these values and a Dutch implementation of IReportViewerMessages are presented.