How to add static assets

This guide shows you how to add static assets to your dashboard. Static assets are images that you would like to show in your dashboard, or custom CSS and JS files with which you would like to enhance/change the appearance of your dashboard.

To add images, custom CSS or JS files, create a folder named assets in the root of your app directory and insert your files. Assets included in that folder are automatically served after serving Vizro's static files via the external_stylesheets and external_scripts arguments of Dash. The user's assets folder thus always takes precedence.

Example folder structure

├── app.py
├── assets
│   ├── css
│       ├── **/*.css
│   ├── images
│       ├── icons
│           ├── collections.svg
│       ├── app.svg
│       ├── logo.svg
│   ├── favicon.ico

Dash Bootstrap Themes

Note that Vizro is currently not compatible with Dash Bootstrap Themes. Adding a Bootstrap stylesheet will have no visual effect on the components included in Vizro.

Change the favicon

To change the default favicon (website icon appearing in the browser tab), add a file named favicon.ico to your assets folder. For more information, see the Dash documentation.

Change the assets folder path

If you do not want to place your assets folder in the root directory of your app, you can specify an alternative path through the assets_folder argument of the Vizro class.

from vizro import Vizro
import vizro.models as vm

page = <INSERT CONFIGURATION HERE>
dashboard = vm.Dashboard(pages=[page])

app = Vizro(assets_folder="path/to/assets/folder").build(dashboard).run()

Note that in the example above, you still need to configure your Page. See more information in the Pages User Guide.

Include a meta tags image

Vizro automatically adds meta tags to display a preview card when your app is shared on social media and chat clients. To include an image in the preview, place an image file in the assets folder named app.<extension> or logo.<extension>. Vizro searches the assets folder and uses the first one it finds.

Image types of apng, avif, gif, jpeg, jpg, png, svg, and webp are supported.

Add a logo image

Vizro will automatically incorporate the dashboard logo in the top-left corner of each page if an image named logo.<extension> is present within the assets folder.

Image types of apng, avif, gif, jpeg, jpg, png, svg, and webp are supported.

Overwrite global CSS properties

To overwrite any global CSS properties of existing components, target the right CSS property and place your CSS files in the assets folder. This will overwrite any existing defaults for that CSS property. For reference, see the Vizro CSS files.

Customizing global CSS properties

my_css_file.css

h1, h2 {
 color: hotpink;
}

app.pyapp.yamlResult

import os
import vizro.models as vm
from vizro import Vizro

page = vm.Page(
        title="Changing the header color",
        components=[
            vm.Card(
                text="""

                    # This is an <h1> tag

                    ## This is an <h2> tag

                    ###### This is an <h6> tag
                """)
            ],
        )

dashboard = vm.Dashboard(pages=[page])


Vizro().build(dashboard).run()

# Still requires a .py to add data to the data manager and parse YAML configuration
# See yaml_version example
pages:
- components:
    - text: |
        # This is an <h1> tag

        ## This is an <h2> tag

        ###### This is an <h6> tag
      type: card
  title: Changing the header color

Overwrite CSS properties for specific pages

To style components for a specific page, use the page's id in CSS selectors. By default, this is the same as the page title, but such a value might not be a valid CSS identifier. A suitable id must be unique across all models in the dashboard and should contain only alphanumeric characters, hyphens (-) and underscores (_). In particular, note that spaces are not allowed.

Suppose you want to hide the page title on one page only. Here's how you can achieve this:

1. Give a valid id to the Page, for example Page(id="page-with-hidden-title", title="Page with hidden title", ...).
2. Identify the CSS class or CSS id you need to target. To hide the page title, you need to hide the container with the idright-header`.
3. Use the id in combination with CSS selectors to change the relevant CSS properties.
4. Add your custom css file to the assets folder as explained above.

Hide page title on selected pages

my_css_file.css

#page-with-hidden-title #right-header {
  display: none;
}

app.pyapp.yamlResult

import vizro.models as vm
from vizro import Vizro

page_one = vm.Page(
    id="page-with-hidden-title",
    title="Page with hidden title",
    components=[vm.Card(text="""# Placeholder""")]
)

page_two = vm.Page(
    title="Page with shown title",
    components=[vm.Card(text="""# Placeholder""")]
)

dashboard = vm.Dashboard(pages=[page_one, page_two])
Vizro().build(dashboard).run()

# Still requires a .py to add data to the data manager and parse YAML configuration
# See yaml_version example
pages:
- components:
    - text: |
        # Placeholder
      type: card
  title: Page with hidden title
  id: page-with-hidden-title
- components:
    - text: |
        # Placeholder
      type: card
  title: Page with shown title

Overwrite CSS properties in selective components

To adjust CSS properties for specific components, like altering the appearance of a selected Card rather than all Cards, you need to use a CSS selector that targets the right CSS property. If you're unfamiliar with CSS selectors, you can refer to this tutorial for guidance.

Let's say we want to change the background and font-color of a specific Card.

Here's how you can do it:

1. Assign a unique id to the relevant Card, for example: Card(id="custom-card", ...)
2. Run your dashboard and open it in your browser
3. View the HTML source to find the appropriate CSS class or element you need to target. For example, if you inspect a page with Chrome DevTools then you can directly copy the CSS selector.

It's essential to understand the relationship between the targeted CSS class or element and the component assigned the id, for example:

HTML structure of a `Card`

<div class="card">
    <div id="custom-card">
        <p>Lorem ipsum dolor sit amet consectetur adipisicing elit.</p>
    </div>
</div>

• Main element with id: There is a <div> with our id="custom-card".
• Parent element: That <div> is wrapped inside a parent <div> with the class name "card". This is the element we need to target to change the background color.
• Child element: The card text is wrapped inside a <p> that is a child of the <div> with our id. This is the element we need to target to change the font color.

Customizing CSS properties in selective components

my_css_file.css

/* Apply styling to parent */
.card:has(#custom-card) {
  background-color: white;
}

/* Apply styling to child */
#custom-card p {
  color: black;
}

app.pyapp.yamlResult

import vizro.models as vm
from vizro import Vizro

page = vm.Page(
    title="Changing the card color",
    components=[
        vm.Card(id="custom-card", text="""Lorem ipsum dolor sit amet consectetur adipisicing elit."""),
        vm.Card(text="""Lorem ipsum dolor sit amet consectetur adipisicing elit.""")
             ],
)

dashboard = vm.Dashboard(pages=[page])

Vizro().build(dashboard).run()

# Still requires a .py to add data to the data manager and parse YAML configuration
# See yaml_version example
pages:
- components:
    - text: |
        Lorem ipsum dolor sit amet consectetur adipisicing elit.
      type: card
      id: custom-card
    - text: |
        Lorem ipsum dolor sit amet consectetur adipisicing elit.
      type: card
  title: Changing the card color

Order of serving CSS files

CSS properties will be applied with the last served file taking precedence. The order of serving is:

1. Dash built-in stylesheets
2. Vizro built-in stylesheets
3. User assets folder stylesheets

Within each of these categories, individual files are served in alphanumeric order.