# Button Buttons allow users to trigger an action or to navigate to another page. They are available in multiple styles for various purposes. Buttons are ideal for calling attention to actions users need to perform in order to move forward in a flow. ## Example ```python from deephaven import ui btn = ui.button("Press me", on_press=lambda: print("Button clicked")) ``` ## UI recommendations Recommendations for creating clear and effective buttons: 1. Button text should be clear and concise. No more than 4 words or 20 characters is recommended. 2. Use verbs for button text to indicate the action that will be taken when the button is clicked. For example, “Save”, “Delete”, or “Add friend”, rather than “Ok” or “Cancel”. Nouns or adjectives tend to be less clear. 3. Use sentence case for button text with more than one word. For example, “Add friend” instead of “Add Friend” or “ADD FRIEND”. 4. No punctuation is needed at the end of the button text. 5. Use icons only when necessary, and not as a replacement for text or decoration. Icons should be used to provide additional context to the button’s action. 6. When presenting choices, use a single filled accent button to suggest to users the recommended choice, paired with outlined primary or secondary buttons for the other options. This helps to visually distinguish the primary action from the secondary actions. 7. Use negative buttons sparingly, as they can be visually distracting. They should be used for actions that are destructive or irreversible. Consider using [`action_button`](action_button.md) for task-based actions, or in cases where buttons aren’t meant to draw attention to themselves. To represent a binary choice, use a [`toggle_button`](toggle_button.md) instead. If you have a collection of related buttons, you can group them using a [`button_group`](button_group.md). ## Events Buttons accept a value to display and can trigger actions based on events such as setting state when pressed. See the [API Reference]() for a full list of available events. ```python from deephaven import ui @ui.component def counter(): count, set_count = use_state(0) return ui.button( f"Pressed {count} times", on_press=lambda: set_count(count + 1), ) counter_example = counter() ``` ## Variants Buttons can have different styles to indicate their purpose. ```python from deephaven import ui @ui.component def button_variants(): return [ ui.button("Accent fill", variant="accent", style="fill"), ui.button("Accent outline", variant="accent", style="outline"), ui.button("Primary fill", variant="primary", style="fill"), ui.button("Primary outline", variant="primary", style="outline"), ui.button("Secondary fill", variant="secondary", style="fill"), ui.button("Secondary outline", variant="secondary", style="outline"), ui.button("Negative fill", variant="negative", style="fill"), ui.button("Negative outline", variant="negative", style="outline"), ] button_variants_example = button_variants() ``` Static-color buttons are available in white and black. They don’t dynamically change in response to the user’s theme. They should only be used over fixed-color backgrounds, not over theme colors that may change. ```python from deephaven import ui @ui.component def static_buttons(): return [ ui.view( ui.button_group( ui.button("White fill", static_color="white", style="fill"), ui.button( "White outline", static_color="white", style="outline", ), ), background_color="#000066", padding="size-300", ), ui.view( ui.button_group( ui.button("Black fill", static_color="black", style="fill"), ui.button( "Black outline", static_color="black", style="outline", ), ), background_color="#FFFF00", padding="size-300", ), ] static_buttons_example = static_buttons() ``` ## Icon buttons Buttons can have icons when necessary to provide additional context. If no visible label is provided (e.g., an icon-only button), an alternative text label must be provided to identify the control for accessibility using the `aria-label` prop. See [icon](icon.md) for a list of available icons. ```python from deephaven import ui @ui.component def icon_buttons(): return [ ui.button(ui.icon("squirrel"), "Squirrel"), ui.button(ui.icon("squirrel"), aria_label="Squirrel"), ] icon_buttons_example = icon_buttons() ``` ## Pending state Buttons can be in a pending state to indicate that an action is in progress (such as an asynchronous server request). After a one-second delay, an indeterminate spinner will be displayed in place of the button label and icon. You can trigger this behavior by setting the `is_pending` prop. Button events are disabled while `is_pending` is true. ```python from deephaven import ui from threading import Timer @ui.component def pending_button(): [pending, set_pending] = ui.use_state(False) def handle_on_press(): # start an asynchronous thing timeout = Timer(3, callback_finshed) # use a timer to wait 3 seconds timeout.start() # turn on loading spinner set_pending(True) def callback_finshed(): # turn of loading spinner set_pending(False) return ui.button( "Pending request", on_press=handle_on_press, is_pending=pending, variant="accent", ) pending_example = pending_button() ``` ## Disabled state Buttons can be disabled to prevent user interaction. This is useful when the button is not available for interaction, but should still be visible. ```python from deephaven import ui btn = ui.button("Disabled button", is_disabled=True) ``` ## Button links Buttons can be used as links to navigate to another page if the `href` attribute is provided. ```python from deephaven import ui btn = ui.button("Go to deephaven.io", href="https://deephaven.io") ``` ## API reference Buttons allow users to perform an action or to navigate to another page. They have multiple styles for various needs, and are ideal for calling attention to where a user needs to do something in order to move forward in a flow. Python implementation for the Adobe React Spectrum Button component: https://react-spectrum.adobe.com/react-spectrum/Button.html **Returns:** `Element` The rendered button component.