Dependencies ¶

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)
         (call-next-method)))

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))
  (list*
   (reblocks-lass:make-dependency
    `(.my-custom-widget
      :border 2px solid red
      :padding 1em))
   (call-next-method)))

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

API

• [class]
  reblocks/dependencies:dependency

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

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

• [class]
  reblocks/dependencies:remote-dependency

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

• [class]
  reblocks/dependencies:local-dependency

  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.

• [variable]
  reblocks/dependencies:*cache-remote-dependencies-in*
  nil

  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.

• [function]
  reblocks/dependencies:get-content-type
  dependency

  Returns a MIME content type for given dependency.

  It is used when dependency is served locally.

• [reader]
  reblocks/dependencies:get-crossorigin
  (:CROSSORIGIN = "anonymous")

• [reader]
  reblocks/dependencies:get-integrity
  (:integrity = nil)

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

  See more information at: https://www.w3.org/TR/SRI/

• [generic-function]
  reblocks/dependencies:get-path
  dependency

  Returns a path on local disk to serve dependency from.

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

• [generic-function]
  reblocks/dependencies:get-route
  dependency

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

• [reader]
  reblocks/dependencies:get-type
  (:TYPE = (ERROR ":type argument is required."))

• [generic-function]
  reblocks/dependencies:get-url
  dependency

  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.

• [reader]
  reblocks/dependencies:cache-in-memory-p
  (:cache-in-memory = nil)

  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.

• [generic-function]
  reblocks/dependencies:infer-type-from
  path-or-url

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

• [function]
  reblocks/dependencies:push-dependency
  dependency

  Pushes dependency into the currently collected list of dependencies.

  Makes deduplication by comparing dependencies' urls.

• [function]
  reblocks/dependencies:push-dependencies
  list-of-dependencies

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

• [generic-function]
  reblocks/dependencies:render-in-ajax-response
  dependency

  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.

• [generic-function]
  reblocks/dependencies:render-in-head
  dependency

  Renders a piece of html.

• [generic-function]
  reblocks/dependencies:serve
  dependency

  Returns two values - content and content-type.

  Example output::

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

• [macro]
  reblocks/dependencies:with-collected-dependencies
  &body body

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

• [function]
  reblocks/dependencies:make-dependency
  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.

• [generic-function]
  reblocks/dependencies:get-dependencies
  object

  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.