lambdacms-media
===============

This is an extension for [LambdaCms](http://lambdacms.org) which allows admins to
manage media files.

**NOTE:** At this point the functionality provided by this extension is very basic.
Pull requests adding features are most welcome.


### Installing

LambdaCms extensions come as plain Haskell packages and need to be added to the
project's `.cabal` file like any other package dependency.

The following guide expects a newly initialized LambdaCms base application.
When you have an existing base app this guide show still be easy to follow.

In the `library` section of your base application's `.cabal` file append the following
line to `build-depends`:

```
                , lambdacms-media
```

The media extension's admin section needs to be mounted in the base app's
router, therefor add the following line to your `config/routes` file:

```
/admin/media  MediaAdminR          MediaAdmin   getLambdaCmsMedia
```

To `Application.hs` add:

```haskell
import LambdaCms.Media
```

As well as the following line (see the comment):

```haskell
...
    let getLambdaCms = CoreAdmin
        getLambdaCmsMedia = MediaAdmin  -- add this line
        mkFoundation appConnPool = App {..}
...
```

Then proceed by including the `migrateLambdaCmsMedia` function to `Application.hs`
as shown in this snippet:

```haskell
...
    runLoggingT
        (runSqlPool (mapM_ runMigration [migrateAll, migrateLambdaCmsCore, migrateLambdaCmsMedia]) pool)
        (messageLoggerSource theFoundation appLogger)
...
```


To `Foundation.hs` also add `import LambdaCms.Media` and the following two
lines (see comments):

```haskell
...
    , getLambdaCms   :: CoreAdmin
    , getLambdaCmsMedia :: MediaAdmin  -- add this line
    }
...
    adminMenu = (defaultCoreAdminMenu CoreAdminR)
                ++ (defaultMediaAdminMenu MediaAdminR)  -- add this line
    renderLanguages _ = ["en", "nl"]
...
```

The last line hooks the media admin section into the admin menu.

Finally the following instance needs to be defined in `Foundation.hs`:

```haskell
instance LambdaCmsMedia App where
  mediaR       = MediaAdminR
  staticDir y  = appStaticDir $ appSettings y
  staticRoot _ = "/static"
```


That's it! You can now `cabal install` the new dependency and run
`yesod devel` to test drive the freshly installed extension.


### Using media in another LambdaCms extension

A common usecase would be to use the "media" that are managed using the
`lambdacms-media` extension in other extensions. For example: to add an
image to a blog post.

First off all the `lambdacms-media` package needs to become a package
dependency of that particular extension's package.

Then we can add an `imageId` to the `Post` model.

```
Post
  title Text
  body Text
  imageId MediaId Maybe
```

To make it all work we need to put a constraint on the type class
defined in the `Foundation.hs`:

```haskell
...
class LambdaCmsMedia master => MysitePostSub master where
...
```

After this the `attachedMaybeMedia` function may be used in the
handler functions of the blog post extension.


### License

All code in this repository is released under the MIT license, as specified
in the [LICENSE file](https://github.com/lambdacms/lambdacms/blob/master/LICENSE).