When Reblocks renders page, it collects CSS and JS dependencies from all widgets by calling generic-function reblocks/dependencies:get-dependencies. Also, this function is called on the current app to get such common dependencies as jQuery and CSS framework.

If you are defining your own method for reblocks/dependencies:get-dependencies generic-function, make sure it returns a list of reblocks/dependencies:dependency objects.

Typically, you already have JS or CSS file somewhere near your ASDF system. In this case, you can use reblocks/dependencies:make-dependency function like this:

(defmethod reblocks/dependencies:get-dependencies ((app my-app))
  (list* (reblocks/dependencies:make-dependency "js/my-app.js"
                                                :system :some-asdf-system)

Other way to specify a dependency is to use Parenscript or LASS to define JS or CSS right inside the method. Here we define CSS code for the widget:

(defmethod reblocks/dependencies:get-dependencies ((widget my-custom-widget))
      :border 2px solid red
      :padding 1em))

Pay attention, this code uses REBLOCKS-LASS:MAKE-DEPENDENCY function which is available from the separate asdf system REBLOCKS-LASS.


This class represents a web-dependency. It could be CSS, JS or an image.

All dependencies are divided into remote-dependency or local-dependency.

Remote dependencies refer some URLs. Usually these dependencies are served from a CDN.

Local dependencies are served by the same webserver which renders reblocks widgets.

Each local dependency should provide a route, which will be added to the server routing table. Also, it might define a path to the file on the local file-system.

If this variable is set to a pathname, then remote dependencies will be cached and served as local dependencies.

This pathname should point to a directory where cached dependencies will be stored.

Returns a MIME content type for given dependency.

It is used when dependency is served locally.

A hash, used by modern browsers for subresource integrity checking.

See more information at:

Returns a path on local disk to serve dependency from.

This could be a real source file or a cached version of remote dependency.

This method should return a routes:route object if dependency should ber served from local server.

(:TYPE = (ERROR ":type argument is required."))

Returns URL of the dependency.

If dependency should be served by the server, second value is :local. Otherwise it is :external. Also, in first case dependency's URL should have only path part, like /local/css/bootstrap.css.

When true, then on creation dependency will read file's data into the memory. This is useful for applications, deployed as a single executable file. Create such dependencies in compile time and store in a global variable.

Returns a keyword meaning content type of the dependency by infering it from URL or a path

Pushes dependency into the currently collected list of dependencies.

Makes deduplication by comparing dependencies' urls.

Same as `push-dependency' but for the list.

Returns a JS code to dynamically include a CSS or JS dependency into a webpage on AJAX response.

This makes possible to load new styles and code for widgets which can appear on a page as a response to some action.

Returns two values - content and content-type.

Example output::

(values "body {background: light-green;}" "text/css")

Use this macro to wrap code which may push new dependencies for the page or an action.

path-or-url &key system type integrity crossorigin cache-in-memory

Creates a JavaScript dependency, served from the disk.

If the system's name is given, then the path is calculated relatively to this system's source root.

Returns a list of object's dependencies.

Object could be an application or a widget. Reblocks will call this method for application and every widget on a page to gather necessary dependencies and to inject them into resulting HTML.