Add a Report Storage (ASP.NET MVC)
- 12 minutes to read
Design Considerations
When you add the End-User Report Designer for Web to your project, it operates without a report storage. You should consider whether your application requires a custom report storage and think ahead about the implementation details. The table below lists the functions that will be unavailable to end users without a report storage registered in your application.
| Commands/Functions | With Storage | Without Storage |
|---|---|---|
| Save |  |
|
| Save As | |
|
| Open | |
|
| New | |
|
| New via Wizard | |
|
| Manage Subreports | |
As you can see in the table above, you can edit a report, but cannot manipulate multiple stored report definitions. If these limitations are suitable for your application, you can work with reports without a custom storage.
Operation without a Report Storage
Initially the Report Designer operates without the New via Wizard, Open and Save As menu commands. This operation mode also doesn’t allow end users to manage Subreports - a double click on a subreport has no effect.
The client-side API methods that allows you to load and save a report do not work without a report storage. Use the following server-side API to load a report to the End-User Designer and save user changes:
| API | Description |
|---|---|
| ASPxReportDesigner.OpenReport | Load a report layout into the Designer. |
| ASPxReportDesigner.OpenReportXmlLayout(Byte[]) | Load a report layout from the byte array of XML data (REPX format) into the Designer. |
| ReportDesignerSettings.SaveCallbackRouteValues | Specifies the Controller and Action that allows you to get the report layout as a byte array of XML data and save a report to the REPX file. |
Operation with a Report Storage
To save and load reports, the DevExpress Web Report Designer requires access to a storage medium (a database, file system, cloud service, etc.). To add a server-side report storage medium to your web application, you must create and register a custom report storage class.
Create and Register a Report Storage
Follow the steps below to create a server-side storage for web reports.
Create a Report Storage Class
Create a class that inherits from the abstract ReportStorageWebExtension class. You can use one of the following methods:
If you use the DevExpress Project Wizard, leave the Add Report Storage option checked. The wizard generates and registers a file system report storage. You can specify the class name in the Report Storage Name field:
Important
The template generates a sample storage (a ReportStorageWebExtension descendant) for demonstration purposes only. Create your own implementation for use in production.
Click Add New Item in the Visual Studio Designer and select the DevExpress v23.2 Report Storage Web item in the Reporting section:
You can use the ASP.NET MVC extension wizard:
Override Class Methods
You need to implement the following methods:
| Method | Description |
|---|---|
| IsValidUrl | Determines whether the URL passed to the current report storage is valid. Implement your own logic to prohibit URLs that contain spaces or other specific characters. Return true if no validation is required. |
| CanSetData | Determines whether a report with the specified URL can be saved. Add custom logic that returns false for reports that should be read-only. Return true if no valdation is required. This method is called only for valid URLs (if the IsValidUrl method returns true). |
| SetData | Saves the specified report to the report storage with the specified URL (i.e., it saves existing reports only). |
| SetNewData | Allows you to validate and correct the specified URL. This method also allows you to return the resulting URL and to save your report to a storage. The method is called only for new reports. |
| GetData | Uses a specified URL to return report layout data stored within a report storage medium. This method is called if the IsValidUrl method returns true. You can use the GetData method to process report parameters sent from the client if the parameters are included in the report URL’s query string. |
| GetUrls | Returns a dictionary that contains the report URLs and display names. |
In the following table, select a column that describes the user action. Then, read the entries top to bottom for information on the order of method calls. The table also indicates the moments when the designer invokes Open Report and Save Report dialogs.
| Method/Command | Save As | Save | Open |
|---|---|---|---|
| GetUrls | |
|
|
| (Open Report dialog) | |
||
| IsValidUrl | |
|
|
| CanSetData | |
||
| (Save Report dialog) | |
||
| SetNewData | |
||
| SetData | |
||
| GetData | |
||
| GetUrls | |
For more information on how the reports and documents are stored, review the following help topic: Store Report Layouts and Documents.
Register a Storage
Skip this step if you used a project template, item template, or smart tag to generate your report storage class. If you declared a ReportStorageWebExtension descendant manually, create a new instance and pass it to the static ReportStorageWebExtension.RegisterExtensionGlobal method at application startup:
public class MvcApplication : System.Web.HttpApplication {
protected void Application_Start() {
// ...
DevExpress.XtraReports.Web.Extensions.ReportStorageWebExtension.RegisterExtensionGlobal(new CustomReportStorageWebExtension);
// ...
}
}
Report Storage Examples
Database Sample Storage
using System;
using System.Linq;
using System.Collections.Generic;
using DevExpress.Xpo;
using DevExpress.XtraReports.UI;
using DevExpress.XtraReports.Web.Extensions;
using System.IO;
using Mvc_DbStorage_Sample.Services.DAL;
namespace Mvc_DbStorage_Sample.Services {
public class CustomReportStorageWebExtension : ReportStorageWebExtension {
public override bool CanSetData(string url) {
// Check if the URL is available in the report storage.
using (var session = SessionFactory.Create()) {
return session.GetObjectByKey<ReportEntity>(url) != null;
}
}
public override byte[] GetData(string url) {
// Get the report data from the storage.
using (var session = SessionFactory.Create()) {
var report = session.GetObjectByKey<ReportEntity>(url);
return report.Layout;
}
}
public override Dictionary<string, string> GetUrls() {
// Get URLs and display names for all reports available in the storage
using (var session = SessionFactory.Create()) {
return session.Query<ReportEntity>().ToDictionary<ReportEntity, string, string>(report => report.Url, report => report.Url);
}
}
public override bool IsValidUrl(string url) {
// Check if the specified URL is valid for the current report storage.
// In this example, a URL should be a string containing a numeric value that is used as a data row primary key.
return true;
}
public override void SetData(XtraReport report, string url) {
// Write a report to the storage under the specified URL.
using (var session = SessionFactory.Create()) {
var reportEntity = session.GetObjectByKey<ReportEntity>(url);
MemoryStream ms = new MemoryStream();
report.SaveLayoutToXml(ms);
reportEntity.Layout = ms.ToArray();
session.CommitChanges();
}
}
public override string SetNewData(XtraReport report, string defaultUrl) {
// Save a report to the storage under a new URL.
// The defaultUrl parameter contains the report display name specified by a user.
if (CanSetData(defaultUrl))
SetData(report, defaultUrl);
else
using (var session = SessionFactory.Create()) {
MemoryStream ms = new MemoryStream();
report.SaveLayoutToXml(ms);
var reportEntity = new ReportEntity(session) {
Url = defaultUrl,
Layout = ms.ToArray()
};
session.CommitChanges();
}
return defaultUrl;
}
}
}
File System Sample Storage
Note
You can create a sample Reporting ASP.NET MVC application using Visual Studio project template. The sample application includes a file-based report storage. Review the following help topic for more information: : Create an ASP.NET MVC Application with a Report Designer.
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.ServiceModel;
using DevExpress.XtraReports.Web.Extensions;
using DevExpress.XtraReports.UI;
using ReportAtRuntimeMvcApp.PredefinedReports;
// ...
public class CustomReportStorageWebExtension : DevExpress.XtraReports.Web.Extensions.ReportStorageWebExtension
{
readonly string reportDirectory;
const string FileExtension = ".repx";
public CustomReportStorageWebExtension(string reportDirectory) {
if (!Directory.Exists(reportDirectory)) {
Directory.CreateDirectory(reportDirectory);
}
this.reportDirectory = reportDirectory;
}
private bool IsWithinReportsFolder(string url, string folder) {
var rootDirectory = new DirectoryInfo(folder);
var fileInfo = new FileInfo(Path.Combine(folder, url));
return fileInfo.Directory.FullName.ToLower().StartsWith(rootDirectory.FullName.ToLower());
}
public override bool CanSetData(string url) {
// Determines whether a report with the specified URL can be saved.
// Add custom logic that returns **false** for reports that should be read-only.
// Return **true** if no valdation is required.
// This method is called only for valid URLs (if the **IsValidUrl** method returns **true**).
return true;
}
public override bool IsValidUrl(string url) {
// Determines whether the URL passed to the current report storage is valid.
// Implement your own logic to prohibit URLs that contain spaces or other specific characters.
// Return **true** if no validation is required.
return Path.GetFileName(url) == url;
}
public override byte[] GetData(string url) {
// Uses a specified URL to return report layout data stored within a report storage medium.
// This method is called if the **IsValidUrl** method returns **true**.
// You can use the **GetData** method to process report parameters sent from the client
// if the parameters are included in the report URL's query string.
try {
if (Directory.EnumerateFiles(reportDirectory).Select(Path.GetFileNameWithoutExtension).Contains(url))
{
return File.ReadAllBytes(Path.Combine(reportDirectory, url + FileExtension));
}
if (ReportsFactory.Reports.ContainsKey(url))
{
using (MemoryStream ms = new MemoryStream()) {
ReportsFactory.Reports[url]().SaveLayoutToXml(ms);
return ms.ToArray();
}
}
} catch (Exception) {
throw new FaultException(new FaultReason("Could not get report data."), new FaultCode("Server"), "GetData");
}
throw new FaultException(new FaultReason(string.Format("Could not find report '{0}'.", url)), new FaultCode("Server"), "GetData");
}
public override Dictionary<string, string> GetUrls() {
// Returns a dictionary that contains the report names (URLs) and display names.
// The Report Designer uses this method to populate the Open Report and Save Report dialogs.
return Directory.GetFiles(reportDirectory, "*" + FileExtension)
.Select(Path.GetFileNameWithoutExtension)
.Union(ReportsFactory.Reports.Select(x => x.Key))
.ToDictionary<string, string>(x => x);
}
public override void SetData(XtraReport report, string url) {
// Saves the specified report to the report storage with the specified name
// (saves existing reports only).
if(!IsWithinReportsFolder(url, reportDirectory))
throw new FaultException(new FaultReason("Invalid report name."), new FaultCode("Server"), "GetData");
report.SaveLayoutToXml(Path.Combine(reportDirectory, url + FileExtension));
}
public override string SetNewData(XtraReport report, string defaultUrl) {
// Allows you to validate and correct the specified name (URL).
// This method also allows you to return the resulting name (URL),
// and to save your report to a storage. The method is called only for new reports.
SetData(report, defaultUrl);
return defaultUrl;
}
}
Access the ASP.NET Session
If the ASP.NET End-User Report Designer works with a custom report storage, it uses a separate HTTP handler module for open and save operations. This means that the HttpContext.Session and HttpContext.User properties are not available from custom report storage code.
For more information, review the following help topic: Access HttpContext.Session in Services (ASP.NET Web Forms).