Button

in namespace DotVVM.Framework.Controls

Renders the HTML button which is able to trigger a postback.

Usage & Scenarios

This control renders HTML button which is able to trigger a postback.

Sample 1: Basic Usage

The Button control has a Text property that holds the text displayed in the button.

In the Click event you can specify which method will be called in the viewmodel.

page.dothtml
ViewModel.cs

<dot:Button Click="{command: Calculate()}" Text="Sample Button" />

<dot:Literal Text="{value: CurrentValue}"></dot:Literal>

using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.builtin.Button.sample1
{
    public class ViewModel : DotvvmViewModelBase
    {
        public int CurrentValue { get; set; } = 0;

        public void Calculate()
        {
            CurrentValue++;
        }

    }
}

Sample 2: Disable or Hide the Button

To disable or enable the button, use the Enabled property. It supports the data-binding.

It's also possible to hide the button completely by using the Visible property.

page.dothtml
ViewModel.cs

<dot:Button Click="{command: SetVisible()}" Text="Button" Enabled="{value: Enabled}"/>

<dot:Button Click="{command: SetEnabled()}" Text="Invisible Button" Visible="{value: Visible}"/>

using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.builtin.Button.sample2
{
    public class ViewModel : DotvvmViewModelBase
    {

        public bool Enabled { get; set; } = true;

        public bool Visible { get; set; } = false;

        public void SetEnabled()
        {
            Enabled = true;
            Visible = false;
        }

        public void SetVisible()
        {
            Visible = true;
            Enabled = false;
        }

    }

}

Sample 3: Button Types

The Button control has the ButtonTagName property which specifies the tag rendered by the button.
Pass either input (<input ... />) or button (<button ... />) values.

You can also choose whether it is a submit button or a normal button using the IsSubmitButton property.

page.dothtml
ViewModel.cs

<dot:Button Click="{command: Calculate()}" Text="Button with Input tag" ButtonTagName="input"/>

<dot:Button Click="{command: ShowMessage()}" Text="Submit Button" IsSubmitButton="true"/>

<dot:Literal Text="{value: Message}"/>

<dot:Literal Text="Current value: "></dot:Literal><dot:Literal Text="{value: CurrentValue}"/>

<dot:Literal Text="Submitted value: "></dot:Literal><dot:Literal Text="{value: SubmittedValue}"/>

using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.builtin.Button.sample3
{
    public class ViewModel : DotvvmViewModelBase
    {
        public int SubmittedValue { get; set; } = 0;
        public int CurrentValue { get; set; } = 0;

        public string Message { get; set; } = "";

        public void Calculate()
        {
            CurrentValue++;
            Message = "";
        }

        public void ShowMessage()
        {
            Message = "Value submitted.";
            SubmittedValue = CurrentValue;
        }

    }
}

Sample 4: Image in the Button

The <button> tag supports more than just a text in the button. Instead of using the Text property, you can put the content inside the button.

page.dothtml
ViewModel.cs

<dot:Button ButtonTagName="button" Click="{command: Click()}">
    <img src="~/images/delete.png" alt="Delete" />
    Delete
</dot:Button>

using DotVVM.Framework.ViewModel;

namespace DotvvmWeb.Views.Docs.Controls.builtin.Button.sample3
{
    public class ViewModel : DotvvmViewModelBase
    {
        
        public void Click()
        {
        }
        
    }
}

Sample 5: Async commands

All DotVVM controls support async methods in command bindings.

You should always use async Task instead of async void - it would probably end with an exception.

page.dothtml
ViewModel.cs

<dot:Button Click="{command: Calculate()}" Text="Sample Button" />

<dot:Literal Text="{value: CurrentValue}"></dot:Literal>

using DotVVM.Framework.ViewModel;
using System.Threading.Tasks;

namespace DotvvmWeb.Views.Docs.Controls.builtin.Button.sample5
{
    public class ViewModel : DotvvmViewModelBase
    {
        public int CurrentValue { get; set; } = 0;

        public async Task Calculate()
        {
            CurrentValue++;
        }

    }
}

Properties

Name	Type	Description	Notes	Default Value
Attributes	Dictionary<String,Object>		attribute inner element static value bindable default	null
ButtonTagName	ButtonTagName	Gets or sets whether the control should render the <input> or the <button> tag in the HTML.	attribute inner element static value bindable default	input
ClientIDMode	ClientIDMode	Gets or sets the client ID generation algorithm.	attribute inner element static value bindable default	Static
DataContext	Object	Gets or sets a data context for the control and its children. All value and command bindings are evaluated in context of this value.	attribute inner element static value bindable default	null
Enabled	Boolean	Gets or sets a value indicating whether the button is enabled and can be clicked on.	attribute inner element static value bindable default	True
ID	String	Gets or sets the unique control ID.	attribute inner element static value bindable default	null
InnerText	String	Gets or sets the inner text of the HTML element.	attribute inner element static value bindable default	null
IsSubmitButton	Boolean	Gets or sets whether the control should render a submit button or a normal button (type="submit" or type="button"). The submit button has some special features in the browsers, e.g. handles the Return key in HTML forms etc.	attribute inner element static value bindable default	False
Text	String	Gets or sets the text on the button.	attribute inner element static value bindable default
Visible	Boolean	Gets or sets whether the control is visible.	attribute inner element static value bindable default	True

Events

	Name	Type	Description
	Click	Command	Gets or sets the command that will be triggered when the button is clicked.

HTML produced by the control

Depending on the ButtonTagName property, the control renders one of these HTML elements:

<input type="submit" onclick="dotvvm.postBack(...);" value="Text" />

<button type="submit" onclick="dotvvm.postBack(...);">
	Text
</button>