action.md

XModule Reference: xaction

Execute arbitrary actions on external sources with xaction

Feature

• xaction @boost-rule
  After a repository target is finished constructing its contents, targets with properties with this feature will run the given boost-rule and or boost-actions by the same name.

  argument	description
  $(<)	log file
  $(>)	repository directory

  Example template:

  • In requirements for some xmodule repository target

  <xaction>@myAction
  

  • If your 'myAction' needs to execute as a Boost.Build rule, in the same module:

  rule myAction ( target : source : properties * )
  {
      # Take some action here.
      
      # Example:
      #   Set custom value on target from boost rule
      CUSTOM_VALUE on $(target) = "whatever" ;
  }
  

  • If your 'myAction' needs to execute as a Boost.Build actions block, in the same module:

  import xmodule ; # if not already imported
  MyXLOG = [ xmodule.logfile-action ] ; # create variable that contains shell script details
  
  actions myAction
  {
      $(MyXLOG[1])="$(<)"
      (
          # setup logging (add -e if you want to abort on error)
          set -x
          : "comment that will be in log file"
       
          # shell-code-that-does-your-action HERE
          # example:
          cd $(>) # change to repository
          ln -s path/to/file link
       
          # maybe reference 'custom value' added from the myAction rule
          # In this case, both rule and actions blocks are specified
          echo $(CUSTOM_VALUE)
    
      ) $(MyXLOG[2])
  }
  
  

  In particular, the MyXLOG portions of the template handle the writing of the log file and error handling.

  actions myLoggingAction
  {
      $(MyXLOG[1])="$(<)"
      (
          echo "This is written to log file."
          
      ) $(MyXLOG[2])
  }