Prepare a Dashboard Storage

• Aug 01, 2019
• 3 minutes to read

The Web Dashboard requires creating a special storage used to keep dashboards. End-users can save new dashboards to this storage and access existing dashboards from it.

The following storage types are available:

• In-Memory Storage
• File Storage
• Custom Storage

To create a storage that contains dashboards, pass the required storage instance to the static DashboardConfigurator.SetDashboardStorage method as a parameter.

In-Memory Storage

In-memory dashboard storage is used for storing dashboards by default. The Web Dashboard uses the DashboardInMemoryStorage by default if you do not create a storage.

Use the following method overload to specify in-memory storage:

• DashboardConfigurator.SetDashboardStorage(DashboardInMemoryStorage)

The following code snippet shows how to set in-memory storage for dashboards:

C#

public void ConfigureServices(IServiceCollection services) {
    services
        .AddMvc()
        .AddDefaultDashboardController((configurator, serviceProvider)  => {
            // ...
            configurator.SetDataSourceStorage(new DataSourceInMemoryStorage());
        });
    // ...
}

File Storage

File dashboard storage is used to store dashboards in a file system.

Use the following method overload to specify file storage:

• DashboardConfigurator.SetDashboardStorage(DashboardFileStorage)

The following code snippet shows how to use the App_Data/Dashboards project’s folder to store dashboards in a file system:

C#

public void ConfigureServices(IServiceCollection services) {
    services
        .AddMvc()
        .AddDefaultDashboardController((configurator, serviceProvider)  => {
            // ...
            configurator.SetDashboardStorage(new DashboardFileStorage(Path.Combine(Env.ContentRootPath, "App_Data", "Dashboards")));
        });
    // ...
}

Custom Storage

You can provide custom logic for managing dashboards by implementing the IDashboardStorage or IEditableDashboardStorage interfaces that provide an API used to manage dashboards:

• The IDashboardStorage.GetAvailableDashboardsInfo method returns information about stored dashboards.
• The IDashboardStorage.LoadDashboard/IDashboardStorage.LoadDashboard methods allows you to load/save the dashboard from/to the storage.
• The IEditableDashboardStorage.AddDashboard method allows you to add a new dashboard to the storage.

Use the following method overload to specify custom storage:

• DashboardConfigurator.SetDashboardStorage(IEditableDashboardStorage)
• DashboardConfigurator.SetDashboardStorage(IDashboardStorage)

The following example shows how to create custom dashboard storage for a Web Dashboard by implementing the IEditableDashboardStorage interface. In this example, a DataSet is used as in-memory dashboard storage. This DataSet can be used later to save dashboards in the database using DataAdapter.

Startup.cs

static CustomDashboardStorage dashboardStorage = new CustomDashboardStorage();

public void ConfigureServices(IServiceCollection services) {
    services
        .AddMvc()
        .AddDefaultDashboardController((configurator, serviceProvider)  => {
            // ...
            configurator.SetDashboardStorage(dashboardStorage );
        });
    // ...
}

DashboardStorageDataSet.cs

using System;
using System.Data;

namespace DashboardMainDemo {
    public class DashboardStorageDataSet : DataSet
    {
        public DashboardStorageDataSet() {
            DataTable table = new DataTable("Dashboards");
            DataColumn idColumn = new DataColumn("DashboardID", typeof(Int32));
            idColumn.AutoIncrement = true;
            idColumn.AutoIncrementSeed = 1;
            idColumn.Unique = true;
            idColumn.AllowDBNull = false;
            table.Columns.Add(idColumn);
            table.Columns.Add("DashboardXml", typeof(string));
            table.Columns.Add("DashboardName", typeof(string));
            table.PrimaryKey = new DataColumn[] { idColumn };
            this.Tables.Add(table);
        }
    }
}

DashboardStorage.cs

using DevExpress.DashboardWeb;
using System.Collections.Generic;
using System.Data;
using System.Xml.Linq;

namespace DashboardMainDemo {
    public class CustomDashboardStorage : IEditableDashboardStorage {
        DashboardStorageDataSet dashboards = new DashboardStorageDataSet();

        // Adds a dashboard with the specified ID and name to a DataSet. 
        // Note that the 'DashboardID' column is an auto-increment column that is used to store unique dashboard IDs.
        public string AddDashboard(XDocument dashboard, string dashboardName) {
            DataRow newRow = dashboards.Tables[0].NewRow();
            newRow["DashboardName"] = dashboardName;
            newRow["DashboardXml"] = dashboard;
            dashboards.Tables[0].Rows.Add(newRow);
            return newRow["DashboardID"].ToString();
        }

        // Gets information about dashboards available in a DataSet.
        public IEnumerable<DashboardInfo> GetAvailableDashboardsInfo() {
            List<DashboardInfo> dashboardInfos = new List<DashboardInfo>();
            foreach (DataRow row in dashboards.Tables[0].Rows) {
                DashboardInfo dashboardInfo = new DashboardInfo();
                dashboardInfo.ID = row["DashboardID"].ToString();
                dashboardInfo.Name = row["DashboardName"].ToString();
                dashboardInfos.Add(dashboardInfo);
            }
            return dashboardInfos;
        }

        // Loads a dashboard corresponding to the specified ID.
        public XDocument LoadDashboard(string dashboardID) {
            DataRow currentRow = dashboards.Tables[0].Rows.Find(dashboardID);
            XDocument dashboardXml = XDocument.Parse(currentRow["DashboardXml"].ToString());
            return dashboardXml;
        }

        // Saves the dashboard with the specified ID to a DataSet.
        public void SaveDashboard(string dashboardID, XDocument dashboard) {
            DataRow currentRow = dashboards.Tables[0].Rows.Find(dashboardID);
            currentRow["DashboardXml"] = dashboard;
        }
    }
}