Node Action

A node action is a python script.

This script is formed by the concatenation of three parts:

• Project head script
• Type head script
• Node action script

Before the execution, some environment variables are set in this order:

• Graph variables: MGVPROJECTNAME, MGVPATTERNNAME, MGVGRAPHPATH, MGVGRAPHKEYS, MGVGRAPHNAME, MGVGRAPHFILEPATH and KEY*
• Graph custom variables
• Node variables: MGVNODEPATH, MGVNODENAME, MGVNODETYPE and MGVNODEVERSION
• Inputs, as MGVINPUTS or MGVINPUTS_OUT
• Project context
• Node type files
• Node parameters
• Node custom variables

See Variables for an exhaustive list of Mangrove auto generated variables.

Each variable is recursively resolved with the whole set. For example:

• user : toto
• graph name : tutu
• a node parameter : FOO = “$USER”
• a type file : OUT = “${MGVGRAPHNAME}/${FOO}/bar”

The resulting OUT value will be : “tutu/toto/bar”

Inputs variables:

If a node is from a type with a type file X, an environment variable X will be created.

If 3 nodes A, B and C are connected to a node D, with a type file X for A and B, and Y for C, an execution on node D will set :

• an environment variables MGVINPUTS = “X;Y”
• an environment variables MGVINPUTS_X = “X_VALUE_OF_A;X_VALUE_OF_B”
• an environment variables MGVINPUTS_Y = “Y_VALUE_OF_C”