Permalink
Find file
Fetching contributors…
Cannot retrieve contributors at this time
97 lines (77 sloc) 3.97 KB
# Blog description
The blog is written in the Rails-like style. It utilizes the following principles:
1) MVC architecture;
2) RESTfull design;
3) Convention over configuration;
4) DRY (Don't repeat yourself);
5) Instant gratification.
## Architecture overview
The directory structure is the following:
blog/templates -- root directory for views. It contains subdirrectories for each
entity (post, comment, user) and the common application templates
located in the dirrectory app.
blog/src/blog/system -- contains the common functionality (utils.clj), databse
connectivity options (db.clj), and the router (routes.clj).
blog/src/blog/controllers -- directory for controllers.
blog/src/blog/model -- directory for models.
Controller here contains all the business logic. It accepts the user input,
interacts with the database and renders a response (or redirects to another page).
Model is just a means of interecting with the database. It contains functions for
confinient fetching the entities, creating/updating/deleting them.
Views are implemented using the clj-soy library which is a wrapper over the
Google Closure Templates. More documentation and usage examples are here:
http://code.google.com/closure/templates .
## Application description
The code contains many comments that's why there is not so much description here.
Just follow some advises.
1) Do not dig deeply into system/utils.clj. It is a bit complicated and should be
used "as-is". For those who are interested in it -- it has good comments and usage examples.
2) Define routes for your RESTfull action using the "route" macro:
E.g. (route GET "/post/show/:id" post/show)
It has the following syntax: (route <GET/POST> <page_address> <controller_function>).
Define all the URL-parameters as keywords (:id -- is the parameter here).
3) Define the controller actions using the "defaction" macro. It automates destructuring
of the parameters. For example:
(defaction show [id]
. . .)
In this case there are three local variables available inside the created function show:
* session -- hash-map which holds the session;
* params -- hash-map which holds all the user parameters (URL parameters and POST-ed html-form parameters);
* id -- destructured id parameter.
You don't need to destructure the parameters manually. The "defaction" macro will process all the parameters
in the vector and destructure them automatically.
4) Use the "render-action" macro to render a RESTfull action. It has the following format:
(render-action <entity>#<action> <parameters>)
For example:
(render-action post#show
{:post (post/fetch id)
:comment_list (comment/fetch-list id)}))
It will automatically locate the template "templates/post/show.soy", decorate it with the
application template "templates/app/post.soy" and provide the parameters there.
5) Use the "map->soy" macro to provide any nested paremeters to the template. Example:
(render-action post#index
{:post_list (post/fetch-list)
:extra (map->soy {:editable editable})})))
Here :extra holds a nested hash-map. The clj-soy library can't process it directly,
because the map must contain strings as keys instead of keywords. Thus the map
{:a 1, :b 2} should be transformed to {"a" 1, "b" 2}. The macro "map->soy" does this
transformation.
6) Use the "struct-map->soy" macro to transform the database data to the clj-soy-friendly
format. Example:
(defn fetch [id]
(struct-map->soy
(sql/with-connection *db*
(sql/with-query-results post
[(str "SELECT * FROM post where id = " id)]
(first (doall post))))))
## Usage
1) Create mysql database. The scripts are located in blog/sql/db.sql.
2) Download an install the mysql-connector-java (http://dev.mysql.com/downloads/connector/j/)
as a maven artifact. Just run the "lein deps" command,
it will fail and tell you what to do to install the mysql-connector-java.
3) Run the application:
$ lein deps
$ lein ring server
## License
Copyright (C) 2011 by Dmitry Bushenko
Distributed under the Eclipse Public License, the same as Clojure.