Alert

in namespace DotVVM.Framework.Controls.Bootstrap

Displays contextual feedback messages for users.

Usage & Scenarios

Displays contextual feedback messages for users.

https://getbootstrap.com/docs/3.3/javascript/#alerts

Sample 1: Basic Alert

The Alert control has the Type property which you can use to set the color of the alert message.

If you want to allow the user to hide the alert, use the IsDismissible property.

<bs:Alert Type="Success">
  Alert: type Success
</bs:Alert>

<bs:Alert Type="Danger">
  Alert: type Danger
</bs:Alert>

<bs:Alert Type="Info">
  Alert: type Info
</bs:Alert>

<bs:Alert Type="Warning">
  Alert: type Warning
</bs:Alert>

Sample 2: Dismissible Alert

If you want to allow the user to hide the alert, use the IsDismissible property. When IsDismissible property is set to true the close button will be rendered.

The IsDismissed property gets or sets if the Alert is dismissed.

The Dismissed event is called ofter the Alert is Dismissed.

<bs:Alert IsDismissible="true">
  Dismissable alert
</bs:Alert>

<bs:Alert IsDismissed="{value: Dismissed}" Dismissed="{command: AlertDismissed()}" Text="Click the button" />
<dot:Button Text="Show/Hide" Click="{command: Dismiss()}"/>
Dismissed: {{value: Dismissed}} <br/>
{{value: Text}}
using DotVVM.Framework.Controls.Bootstrap;
using DotVVM.Framework.ViewModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DotVVM.Framework.Hosting;

namespace DotvvmWeb.Views.Docs.Controls.bootstrap.Alert.sample2
{
    public class ViewModel : DotvvmViewModelBase
    {
        public bool Dismissed { get; set; } = false;
        public string Text { get; set; }

        public void AlertDismissed()
        {
            Text = "Alert was hidden.";
        }

        public void Dismiss()
        {
            Dismissed = !Dismissed;
        }
    }
    
}

Sample 3: Common Usage

The typical use of the Alert control is to have 2 properties in the viewmodel (AlertText and AlertType) which are bound to the properties of the Alert control.

Notice that the properties are marked with the Bind attribute setting the direction to ServerToClient. That's because we don't need to send the property values to the server when we are making a postback. We only need to send the new value to the client if the properties are changed.

We suggest to put the AlertText and AlertType properties into the base viewmodel class and create a method which does this kind of exception handling. Then, you can use it on all places, in your application.

@viewModel DotvvmWeb.Views.Docs.Controls.bootstrap.Alert.sample3.ViewModel, DotvvmWeb

<bs:Alert Text="{value: AlertText}" Type="{value: AlertType}" />

<bs:Button Text="Do Something" Click="{command: DoSomething()}"/>
using DotVVM.Framework.Controls.Bootstrap;
using DotVVM.Framework.ViewModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DotVVM.Framework.Hosting;

namespace DotvvmWeb.Views.Docs.Controls.bootstrap.Alert.sample3
{
    public class ViewModel : MyViewModelBase
    {
        
        public void DoSomething()
        {
            ExecuteWithAlert(() =>
            {
                // the action
            });
        }
    }
    
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using DotVVM.Framework.ViewModel;
using DotVVM.Framework.Controls.Bootstrap;
using DotVVM.Framework.Hosting;

namespace DotvvmWeb.Views.Docs.Controls.bootstrap.Alert.sample3
{
    public class MyViewModelBase : DotvvmViewModelBase
    {

        [Bind(Direction.ServerToClient)]
        public string AlertText { get; set; }

        [Bind(Direction.ServerToClient)]
        public AlertType AlertType { get; set; }


        /// <summary>
        /// Executes the specified action and sets the appropriate alert messages.
        /// </summary>
        protected void ExecuteWithAlert(Action actionToExecute, 
            string successText = "The operation was successful.", 
            string errorText = "Sorry, an unexpected error has occurred.")
        {
            try
            {
                // execute the action
                actionToExecute();

                AlertText = successText;
                AlertType = AlertType.Success;
            }
            catch (DotvvmInterruptRequestExecutionException)
            {
                // this exception is used for redirecting - don't catch it
                throw;
            }
            catch (Exception)
            {
                AlertText = errorText;
                AlertType = AlertType.Danger;
            }
        }

    }
}

Properties

Name Type Description Notes Default Value
property icon IsDismissed Boolean Gets or sets whether the alert has been dismissed by the user.
attribute
inner element
static value
bindable
default
False
property icon IsDismissible Boolean Gets or sets whether a close icon should be displayed in the top right corner of the alert.
attribute
inner element
static value
bindable
default
False
property icon Text String Gets or sets the text of the alert.
attribute
inner element
static value
bindable
default
property icon Type AlertType Gets or sets the type of the alert.
attribute
inner element
static value
bindable
default
Success

Events

Name Type Description
event icon Dismissed Action Gets or sets the command that will be triggered when the alert is dismissed.

HTML produced by the control