The Yesod development of Haskell – side-stepping pit development (3)

Today, let's meet Yesod-bin.
Take the following installation steps from a clean environment, for example in Windows

1. Install Haskell-platform (you can manually install cabal and GHC)
2. to update cabal. Cabal Update
3. updates caball-install. Cabal Install–global Cabal-install Remember to take the global parameter, otherwise your update is only in the current cabal environment, and there is nothing luan to switch to a directory with
4. (for example, c:\lib\ Yesod) This directory will become your Yesod home directory, just like the JDK
5. executes cabal sandbox init we use sandbox technology to install the required dependencies in this directory
6. Here you can copy a file called Cabal.config, but I tried two links https://www.stackage.org/nightly-2015-05-28 and http://www.stackage.org/lts/ Cabal.config, instead of causing the Yesod installation to be unsuccessful, skip this step
7. install Yesod-bin. Cabal Install Yesod-bin (in http://blog.pangyanhan.com/haskell/2013-11-31- using-cabal-sandbox-libraries.html here, the 7th and 8th steps are the opposite, but I can not install it according to what he said, and then it succeeds after inversion
8. installs Yesod. Cabal Install Yesod (think there is nothing luan use, but to be safe to install)
9. Set environment variables, C:\lib\yesod.cabal-sandbox and c:\lib\ Yesod.cabal-sandbox\bin added to path, you should notice that there is a yesod.exe under \ bin. Yes, we're going to use this for the next thing.
10. now enters your project directory
11. Execute Yesod Init as prompted to generate the kind of project you need. I chose simple
12. here to test the HelloWorld here http://www.yesodweb.com/book/basics.
    Done

Next we want to engage in database. Experiment with the first code in Http://www.yesodweb.com/book-1.4/persistent.

>-package-db=c:\lib\yesod\.cabal-sandbox\i386-windows-ghc-7.8.3-packages.conf.

No accident, you will receive an error message, indicating that Database.Persist.Sqlite can not find, then we come back to install

Switch to C:\lib\yesod, execute cabal install Persistent-sqlite
Re-execute.

done!

If you want to try a MySQL connection, you can use YESOD init to generate a project with MySQL and then execute

-package-db=c:\lib\yesod\.cabal-sandbox\i386-windows-ghc-7.8.3-packages.conf.d app/main

Will prompt you, Classyprelude.yesod,database.persist.mysql,yesod.static,yesod.jesmini not installed
Or go back to the C:\lib\yesod directory
Execute cabal install yesod.static to eliminate yesod.static and Yesod.jesmini errors
However, when installing cabal install Persistent-mysql, you will be prompted to require a Linux environment to compile the Pcre-light package.

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The Yesod development of Haskell – side-stepping pit development (3)