Bootstrap - Buttons

Bootstrap - Buttons
This chapter covers the use age of Bootstrap button with examples. Anything that is given a class of .btn will inherit the default look of a gray button with rounded corners. However, Bootstrap provides some options to style buttons, which are summarized in the following table −

Class	Description
btn	Default/ Standard button.
btn-primary	Provides extra visual weight and identifies the primary action in a set of buttons.
btn-success	Indicates a successful or positive action.
btn-info	Contextual button for informational alert messages.
btn-warning	Indicates caution should be taken with this action.
btn-danger	Indicates a dangerous or potentially negative action.
btn-link	Deemphasize a button by making it look like a link while maintaining button behavior.

The following example demonstrates all the above button classes −

<!-- Standard button -->
<button type = "button" class = "btn btn-default">Default Button</button>

<!-- Provides extra visual weight and identifies the primary action in a set of buttons -->
<button type = "button" class = "btn btn-primary">Primary Button</button>

<!-- Indicates a successful or positive action -->
<button type = "button" class = "btn btn-success">Success Button</button>

<!-- Contextual button for informational alert messages -->
<button type = "button" class = "btn btn-info">Info Button</button>

<!-- Indicates caution should be taken with this action -->
<button type = "button" class = "btn btn-warning">Warning Button</button>

<!-- Indicates a dangerous or potentially negative action -->
<button type = "button" class = "btn btn-danger">Danger Button</button>

<!-- Deemphasize a button by making it look like a link while maintaining button behavior -->
<button type = "button" class = "btn btn-link">Link Button</button>

Button Size

The following table summarizes the classes used to get buttons of various sizes −

Class	Description
.btn-lg	This makes the button size large.
.btn-sm	This makes the button size small.
.btn-xs	This makes the button size extra small.
.btn-block	This creates block level buttons—those that span the full width of a parent.

The following example demonstrates this −

<p>
   <button type = "button" class = "btn btn-primary btn-lg">
      Large Primary button
   </button>
   
   <button type = "button" class = "btn btn-default btn-lg">
      Large button
   </button>
</p>

<p>
   <button type = "button" class = "btn btn-primary">
      Default size Primary button
   </button>
   
   <button type = "button" class = "btn btn-default">
      Default size button
   </button>
</p>

<p>
   <button type = "button" class = "btn btn-primary btn-sm">
      Small Primary button
   </button>
   
   <button type = "button" class = "btn btn-default btn-sm">
      Small button
   </button>
</p>

<p>
   <button type = "button" class = "btn btn-primary btn-xs">
      Extra small Primary button
   </button>
   
   <button type = "button" class = "btn btn-default btn-xs">
      Extra small button
   </button>
</p>

<p>
   <button type = "button" class = "btn btn-primary btn-lg btn-block">
      Block level Primary button
   </button>
   
   <button type = "button" class = "btn btn-default btn-lg btn-block">
      Block level button
   </button>
</p>

Button State

Bootstrap provides classes which allow you to change the state of buttons as active, disabled etc. each of which are discussed in the following sections.

Active State

Buttons will appear pressed (with a darker background, darker border, and inset shadow) when active. The following table summarizes classes used to make button elements and anchor elements active −

Element	Class
Button element	Use .active class to show that it is activated.
Anchor element	Use .active class to <a> buttons to show that it is activated.

The following example demonstrates this −

<p>
   <button type = "button" class = "btn btn-default btn-lg ">
      Default Button
   </button>
   
   <button type = "button" class = "btn btn-default btn-lg active">
      Active Button
   </button>
</p>

<p>
   <button type = "button" class = "btn btn-primary btn-lg">
      Primary button
   </button>
   
   <button type = "button" class = "btn btn-primary btn-lg active">
      Active Primary button
   </button>
</p>

Disabled State

When you disable a button, it will fade in color by 50%, and lose the gradient.
The following table summarizes classes used to make button element and anchor element disabled −

Element	Class
Button element	Add the disabled attribute to <button> buttons.
Anchor element	Add the disabled class to <a> buttons. Note − This class will only change the <a>'s appearance, not its functionality. You need to use custom JavaScript to disable links here.

The following example demonstrates this −

<p>
   <button type = "button" class = "btn btn-default btn-lg">
      Default Button
   </button>
   
   <button type = "button" class = "btn btn-default btn-lg" disabled = "disabled">
      Disabled Button
   </button>
</p>

<p>
   <button type = "button" class = "btn btn-primary btn-lg">
      Primary button
   </button>
   
   <button type = "button" class = "btn btn-primary btn-lg" disabled = "disabled">
      Disabled Primary button
   </button>
</p>

<p>
   <a href = "#" class = "btn btn-default btn-lg" role = "button">
      Link
   </a>
   
   <a href = "#" class = "btn btn-default btn-lg disabled" role = "button">
      Disabled Link
   </a>
</p>

<p>
   <a href = "#" class = "btn btn-primary btn-lg" role = "button">
      Primary link
   </a>
   
   <a href = "#" class = "btn btn-primary btn-lg disabled" role = "button">
      Disabled Primary link
   </a>
</p>

Button Tags

You may use button classes with <a>, <button>, or <input> element. But it is recommended that you use it with <button> elements mostly to avoid cross browser inconsistency issues.
The following example demonstrates this −

<a class = "btn btn-default" href = "#" role = "button">Link</a>
<button class = "btn btn-default" type = "submit">Button</button>
<input class = "btn btn-default" type = "button" value = "Input">
<input class = "btn btn-default" type = "submit" value = "Submit">