CheckBox
in namespace DotVVM.Framework.Controls
Renders the HTML checkbox control.
Usage & Scenarios
This control renders HTML checkbox.
Sample 1: Basic CheckBox
The CheckBox control has the Checked
property of boolean which indicates whether the control is checked or not.
Optionally, you can use the Text
property to specify the label for the checkbox. Or you can put the label contents inside the dot:CheckBox
element.
<dot:CheckBox Text="CheckBox Label" Checked="{value: Checked}" />
<p>{{value: Checked}}</p>
using DotVVM.Framework.ViewModel;
namespace DotvvmWeb.Views.Docs.Controls.builtin.CheckBox.sample1
{
public class ViewModel : DotvvmViewModelBase
{
public bool Checked { get; set; }
}
}
Sample 2: Multiple CheckBoxes
The CheckBox has also a property CheckedItems
which can hold any collection. This is an alternative to the Checked
property - they cannot be combined.
The collection holds values of all checkboxes which are checked. The value of the checkbox which should be inserted in the collection, is defined in the
CheckedValue
property.
The first two checkboxes will be checked by default because the collection holds initial values "r" and "g". If you uncheck or check a checkbox, the collection will be updated immediately.
You can also modify the collection contents in the viewmodel code which will update the checkbox check states appropriately.
<dot:CheckBox Text="Red" CheckedItems="{value: Colors}" CheckedValue="r" Changed="{command: UpdateSelectedColors()}" />
<dot:CheckBox Text="Green" CheckedItems="{value: Colors}" CheckedValue="g" Changed="{command: UpdateSelectedColors()}" />
<dot:CheckBox Text="Blue" CheckedItems="{value: Colors}" CheckedValue="b" Changed="{command: UpdateSelectedColors()}" />
<p>{{value: SelectedColors}}</p>
using System.Linq;
using System.Collections.Generic;
namespace DotvvmWeb.Views.Docs.Controls.builtin.CheckBox.sample2
{
public class ViewModel
{
public string SelectedColors { get; set; }
public List<string> Colors { get; set; } = new List<string>() {"r", "g"};
public ViewModel()
{
UpdateSelectedColors();
}
public void UpdateSelectedColors()
{
SelectedColors = string.Join(", ", Colors.Select(i => i.ToString()));
}
}
}
Sample 3: CheckBox's Changed Event
The CheckBox has the Changed
event which is fired whenever the checkbox is checked or unchecked.
<dot:CheckBox Checked="{value: Value}" Changed="{command: OnChanged()}" />
<p>{{value: NumberOfChanges}}</p>
using System.Collections.Generic;
namespace DotvvmWeb.Views.Docs.Controls.builtin.CheckBox.sample3
{
public class ViewModel
{
public bool Value { get; set; }
public int NumberOfChanges { get; set; } = 0;
public void OnChanged()
{
NumberOfChanges++;
}
}
}
Real World Sample
The total price is calculated by summing of all CheckedValues
and is updated after any change by Changed
event.
Because the collection holds floats instead of strings, we have to use the {value: 0.5}
binding instead of just "0.5"
.
It would be treated as string otherwise.
<h3>Additional ingredients for your pizza!</h3>
<p>
<dot:CheckBox CheckedItems="{value: Extra}"
Changed="{command: UpdatePrice()}"
CheckedValue="{value: 0.5}" Text="Jalapeño" />
<br />
<dot:CheckBox CheckedItems="{value: Extra}"
Changed="{command: UpdatePrice()}"
CheckedValue="{value: 0.45}" Text="Egg" />
<br />
<dot:CheckBox CheckedItems="{value: Extra}"
Changed="{command: UpdatePrice()}"
CheckedValue="{value: 0.75}" Text="Tuna" />
<br />
<dot:CheckBox CheckedItems="{value: Extra}"
Changed="{command: UpdatePrice()}"
CheckedValue="{value: 0.2}" Text="Garlic" />
<br />
<dot:CheckBox CheckedItems="{value: Extra}"
Changed="{command: UpdatePrice()}"
CheckedValue="{value: 0.8}" Text="Magic Mushrooms" />
</p>
<p>Total price: ${{value: Price}}</p>
using System.Collections.Generic;
using System.Linq;
using DotVVM.Framework.ViewModel;
namespace DotvvmWeb.Views.Docs.Controls.builtin.CheckBox.sample4
{
public class ViewModel : DotvvmViewModelBase
{
public List<double> Extra { get; set; } = new List<double>();
public double Price { get; set; } = 4;
public void UpdatePrice()
{
Price = 4 + Extra.DefaultIfEmpty(0).Sum();
}
}
}
Properties
Name | Type | Description | Notes | Default Value | |
---|---|---|---|---|---|
Attributes | Dictionary<String,Object> |
attribute
static value
|
null | ||
Checked | Boolean? | Gets or sets whether the control is checked. |
attribute
bindable
|
False | |
CheckedItems | IEnumerable | Gets or sets a collection of values of all checked checkboxes. Use this property in combination with the CheckedValue property. |
attribute
static value
bindable
|
null | |
CheckedValue | Object | Gets or sets the value that will be used as a result when the control is checked. Use this property in combination with the CheckedItem or CheckedItems property. |
attribute
static value
bindable
|
null | |
ClientIDMode | ClientIDMode | Gets or sets the client ID generation algorithm. |
attribute
static value
|
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
static value
bindable
|
null | |
Enabled | Boolean | Gets or sets a value indicating whether the control is enabled and can be clicked on. |
attribute
static value
bindable
|
False | |
ID | String | Gets or sets the unique control ID. |
attribute
static value
bindable
|
null | |
IncludeInPage | Boolean | Gets or sets whether the control is included in the DOM of the page. |
attribute
bindable
|
True | |
InnerText | String | Gets or sets the inner text of the HTML element. |
attribute
static value
bindable
|
null | |
Text | String | Gets or sets the label text that is rendered next to the control. |
attribute
static value
bindable
|
||
Visible | Boolean | Gets or sets whether the control is visible. |
attribute
bindable
|
True |
Events
Name | Type | Description | |
---|---|---|---|
Changed | Command | Gets or sets the command that will be triggered when the control check state is changed. |
HTML produced by the control
With no Text
or an inner content specified, the control renders just the checkbox.
<input type="checkbox" data-bind="..." />
If there is a Text
or an inner content, the label is rendered around the checkbox.
<label>
<input type="checkbox" data-bind="..." />
Text or inner content
</label>