Programming Workflow

The following is a suggested workflow for new Pico developers. 

Related information is available in the following resources:

• Developer Tips for Pico Engine
• KRL Programming Tools

1. Create a directory for your project 

   $ mkdir workflow
   $ cd workflow/

2. Initialize the project directory as a Git repository

   $ git init

3. Follow the directions in Setting Up a Git Pre-Commit Hook to Parse KRL to set up the KRL parser and ensure that KRL files are parsed before they are committed. 

4. Create a KRL ruleset as a file in the repository using your favorite editor. There may be a KRL plugin for your editor. 

5. Add the file to the repository and commit it. 

   $ git add hello_world.krl
   $ git commit -a -m "initial commit"
   Flushing com.windley.hello_world
   [master (root-commit) 4a2f95c] initial commit
    1 file changed, 34 insertions(+)
    create mode 100644 hello_world.krl

   With the pre-commit hook in place, you're assured that there are no parse errors in your ruleset if it commits. 

   Also, the pre-commit hook flushes rulesets in a local engine. 

6. install the ruleset in your pico by navigating to the Rulesets page in the pico engine interface and putting it's full URL in the box labeled "Install ruleset from URL:" and clicking the button. We are using the file: URL scheme to load the ruleset from the filesystem directly into the engine rather than relying on an external server. The file URL is the schema file:// prepended to the full pathname of the file (yes, there are three slashes): 
   

   file:///Users/pjw/prog/picolabs/pico_lessons/workflow/hello_world.krl

   

7. You'll now see the ruleset listed in the installed rulesets in the pico. If you click on the "Engine Rulesets" link, you'll navigate to a page that shows the rulesets registered with the engine.

   
   

Notes:

1. If you install a ruleset in a pico it also registers it with the engine. You can then install the same ruleset in another pico without re-registering it. You only need to register a ruleset once. 
2. Rulesets must be flushed whenever they change to force the engine to re-compile the ruleset and incorporate the changes. 
3. The ruleset name (the string following the keyword ruleset in the code) is used as the ruleset identifier (RID) by the engine. 
4. For rulesets that are to be used by multiple engines not running on the same machine, you should use HTTP for ruleset access. Github is a reasonable hosting facility for public rulesets. AWS S3 works well too.