Struct ructe::StaticFiles

pub struct StaticFiles { /* fields omitted */ }

Handler for static files.

Apart from handling templates for dynamic content, ructe also helps with constants for static content.

Most sites that need HTML templates also needs some static resources. Maybe one or several CSS files, some javascript, and / or pictures. A good way to reduce network round-trips is to use a far expires header to tell the browser it can cache those files and don't need to check if they have changed. But what if the files do change? Then pretty much the only way to make sure the browser gets the updated file is to change the URL to the file as well.

Ructe can create content-dependent file names for static files. If you have an image.png, ructe may call it image-SomeHash.png where SomeHash is 8 url-safe base64 characters encoding 48 bits of a md5 sum of the file.

Each static file will be available as a StaticFile struct instance in your templates::statics module. Also, the const STATICS array in the same module will contain a reference to each of those instances.

Actually serving the file is a job for a web framework like iron, nickel or rocket, but ructe helps by packing the file contents into a constant struct that you can access from rust code.

Overview

This section describes how to set up your project to serve static content using ructe.

To do this, the first step is to add a line in build.rs telling ructe to find and transpile your static files:

let mut ructe = Ructe::from_env()?;
ructe.statics()?.add_files("static")?;

Then you need to link to the encoded file. For an image, you probably want to link it from an <img> tag in a template. That can be done like this:

@use super::statics::image_png;
@()
<img alt="Something" src="/static/@image_png.name">

So, what has happened here? First, assuming the static directory in your $CARGO_MANIFEST_DIR contained a file name image.png, your templates::statics module (which is reachable as super::statics from inside a template) will contain a pub static image_png: StaticFile which can be imported and used in both templates and rust code. A StaticFile has a field named name which is a &'static str containing the name with the generated hash, image-SomeHash.png.

The next step is that a browser actually sends a request for /static/image-SomeHash.png and your server needs to deliver it. Here, things depend on your web framework, so we start with some pseudo code. Full examples for warp, gotham, nickel, and iron is available in the ructe repository.

/// A hypothetical web framework calls this each /static/... request,
/// with the name component of the URL as the name argument.
fn serve_static(name: &str) -> Response {
    if let Some(data) = StaticFile::get(name) {
        Response::Ok(data.content)
    } else {
        Response::NotFound
    }
}

The StaticFile::get function returns the &'static StaticFile for a given file name if the file exists. This is a reference to the same struct that we used by the name image_png in the template. Besides the name field (which will be equal to the argument, or get would not have returned this StaticFile), there is a content: &'static [u8] field which contains the actual file data.

Content-types

How to get the content type of static files.

Ructe has support for making the content-type of each static file availiable using the mime crate. Since mime version 0.3.0 was a breaking change of how the mime::Mime type was implemented, and both Nickel and Iron currently require the old version (0.2.x), ructe provides support for both mime 0.2.x and mime 0.3.x with separate feature flags.

Mime 0.2.x

To use the mime 0.2.x support, enable the mime02 feature and add mime 0.2.x as a dependency:

[build-dependencies]
ructe = { version = "^0.3.2", features = ["mime02"] }

[dependencies]
mime = "~0.2"

A Mime as implemented in mime version 0.2.x cannot be created statically, so instead a StaticFile provides pub fn mime(&self) -> Mime.

use templates::statics::image_png;

assert_eq!(format!("Type is {}", image_png.mime()),
           "Type is image/png");

Mime 0.3.x

To use the mime 0.3.x support, enable the mime3 feature and add mime 0.3.x as a dependency:

[build-dependencies]
ructe = { version = "^0.3.2", features = ["mime03"] }

[dependencies]
mime = "~0.3"

From version 0.3, the mime crates supports creating const static Mime objects, so with this feature, a StaticFile simply has a pub mime: &'static Mime field.

use templates::statics::image_png;

assert_eq!(format!("Type is {}", image_png.mime),
           "Type is image/png");

Implementations

impl StaticFiles

pub fn add_files(&mut self, indir: impl AsRef<Path>) -> Result<()>

Add all files from a specific directory, indir, as static files.

pub fn add_files_as(&mut self, indir: impl AsRef<Path>, to: &str) -> Result<()>

Add all files from a specific directory, indir, as static files.

The to string is used as a directory path of the resulting urls, the file names are taken as is, without adding any hash. This is usefull for resources used by preexisting javascript packages, where it might be hard to change the used urls.

Note that some way of changing the url when the content changes is still needed if you serve the files with far expire, and using this method makes that your responsibility rathr than ructes. Either the file may have hashed names as is, or you may use the version number of a 3:rd party package as part of the to parameter.

The to parameter may be an empty string. In that case, no extra slash is added.

pub fn add_file(&mut self, path: impl AsRef<Path>) -> Result<()>

Add one specific file as a static file.

Create a name to use in the url like name-hash.ext where name and ext are the name and extension from path and has is a few url-friendly bytes from a hash of the file content.

pub fn add_file_as(
    &mut self,
    path: impl AsRef<Path>,
    url_name: &str
) -> Result<()>

Add one specific file as a static file.

Use url_name in the url without adding any hash characters.

pub fn add_file_data<P>(&mut self, path: P, data: &[u8]) -> Result<()> where
    P: AsRef<Path>, 

Add a resource by its name and content, without reading an actual file.

The path parameter is used only to create a file name, the actual content of the static file will be the data parameter. A hash will be added to the file name, just as for file-sourced statics.

Examples

With the folloing code in build.rs:

let mut statics = ructe.statics()?;
statics.add_file_data("black.css", b"body{color:black}\n");

A StaticFile named black_css will be defined in the templates::statics module of your crate:

assert_eq!(statics::black_css.name, "black-r3rltVhW.css");

pub fn get_names(&self) -> &BTreeMap<String, String>

Get a mapping of names, from without hash to with.

let mut statics = ructe.statics()?;
statics.add_file_data("black.css", b"body{color:black}\n");
statics.add_file_data("blue.css", b"body{color:blue}\n");
assert_eq!(
    statics.get_names().iter()
        .map(|(a, b)| format!("{} -> {}", a, b))
        .collect::<Vec<_>>(),
    vec!["black_css -> black-r3rltVhW.css".to_string(),
         "blue_css -> blue-GZGxfXag.css".to_string()],
);

Trait Implementations

impl Drop for StaticFiles

fn drop(&mut self)

Write the ending of the statics source code, declaring the STATICS variable.