When working with Julia’s Dash framework, you may want to add a custom CSS file to style your application. This can be done in several ways, each with its own advantages and disadvantages. In this article, we will explore three different options to solve the problem.
Option 1: Inline CSS
The simplest way to add custom CSS to your Dash application is by using inline CSS. This involves directly adding the CSS code within your Julia code. Here’s an example:
using Dash
app = dash()
app.layout = html_div(
style = "color: red; font-size: 20px;",
children = [
html_h1("Hello, Dash!")
]
)
run_server(app)
This approach is straightforward and doesn’t require any additional setup. However, it can become cumbersome if you have a large amount of CSS code or if you want to reuse the same styles across multiple applications.
Option 2: External CSS File
If you have a significant amount of CSS code or want to reuse styles across multiple applications, it’s better to use an external CSS file. Here’s how you can do it:
using Dash
app = dash()
app.css.append_css({
"external_url": "https://example.com/custom.css"
})
app.layout = html_div(
children = [
html_h1("Hello, Dash!")
]
)
run_server(app)
In this approach, we append the URL of the external CSS file to the `app.css` list. This allows you to separate your CSS code from your Julia code, making it easier to manage and reuse styles. However, keep in mind that the external CSS file must be accessible via a URL.
Option 3: CSS Assets Folder
If you prefer to keep your CSS code within your project directory, you can create a CSS assets folder and reference the CSS file from there. Here’s an example:
using Dash
app = dash()
app.css.config.serve_locally = true
app.css.append_css({
"external_url": "/assets/custom.css"
})
app.layout = html_div(
children = [
html_h1("Hello, Dash!")
]
)
run_server(app)
In this approach, we set `app.css.config.serve_locally` to `true` to serve the CSS file from the local assets folder. You can place your custom CSS file in the `assets` folder within your project directory. This option provides more flexibility and control over your CSS code.
After exploring these three options, it is clear that the best approach depends on your specific requirements. If you have a small amount of CSS code or don’t need to reuse styles, inline CSS is the simplest option. However, if you have a significant amount of CSS code or want to reuse styles, using an external CSS file or a CSS assets folder is recommended.
