An advanced web framework using the Haskell programming language. Featuring:
- safety & security guaranteed at compile time
- developer productivity: tools for all your basic web development needs
- raw performance
- fast, compiled code
- techniques for constant-space memory consumption
- asynchronous IO
- this is built in to the Haskell programming language (like Erlang)
- handles a greater concurrent load than any other web application server
cabal update && cabal install yesod
Create a new project after installing
Your application is a cabal package and you use
cabal to install its dependencies.
Installing & isolation
Install conflicts are unfortunately common in Haskell development.
If you are not using any sandbox tools, you may discover that some of the other haskell installs on your system are broken.
You can prevent this by using sandbox tools:
Isolating an entire project with a virtual machine is also a great idea, you just need some tools to help that process. Vagrant is a great tool for that and there is a Haskell Platform installer for it.
cabal-dev creates a sandboxed environment for an individual cabal package.
Instead of using the
cabal command, use the
cabal-dev command which will use the sandbox.
yesod devel --dev when developing your application.
Installing the latest development version from github for use with your application
cabal update cabal install cabal-meta cabal-src
In your application folder, create a
sources.txt file with the following contents:
./ https://github.com/yesodweb/yesod https://github.com/yesodweb/shakespeare https://github.com/yesodweb/persistent https://github.com/yesodweb/wai
./ means build your app. The yesod repos will be cloned and placed in a
cabal-meta install. If you use
cabal-meta --dev install
This should work almost all of the time. You can read more on cabal-meta
If you aren't building from an application, remove the
./ and create a new directory for your sources.txt first.
hsenv (Linux and Mac OS X)
hsenv prevents your custom build of Yesod from interfering with your currently installed cabal packages:
- hsenv creates an isolated environment like cabal-dev
- hsenv works at the shell level, so every shell must activate the hsenv
- cabal-dev by default isolates a single cabal package, but hsenv isolates multiple packages together.
- cabal-dev can isolate multiple packages together by using the -s sandbox argument
The cabal-src tool helps resolve dependency conflicts when installing local packages. This capability is already built in if you are using cabal-dev or cabal-meta. Otherwise install cabal-src with:
cabal install cabal-src
Whenever you would use
cabal install to install a local package, use
Our installer script now uses cabal-src-install when it is available.
Cloning the repos
The above instructions for building the latest should work well. But you can clone the repos without the help of cabal-meta:
for repo in shakespeare persistent wai yesod; do git clone http://github.com/yesodweb/$repo ( cd $repo git submodule update --init ) done
Building your changes to Yesod
Yesod is composed of 4 "mega-repos", each with multiple cabal packages.
./script/install will run tests against each package and install each package.
install package in all repos
for repo in shakespeare persistent wai yesod; do pushd $repo ./scripts/install popd done
Clean build (sometimes necessary)
Building individual packages
# move to the individual package you are working on cd shakespeare-text # build and test the individual package cabal configure -ftest --enable-tests cabal build cabal test