Expression Style

Adopting a common, shared, standard style for all expressions, scripts and macros makes it easier to "read" them and quickly understand what they are doing. In general PhixFlow ignores all spacing around the functional elements however spacing and layout makes the meaning much clearer for human readers!

This page provides recommended styles for key functional elements.

General

• Item properties
  • All items in PhixFlow have a description property. We recommend you add a description to any item you create.
    Anybody looking at a model or application will first look at the descriptions of the items within it.  For example, in an analysis model, they should be able to discern the flow and the high-level logic of the model just from the descriptions.
  • In analysis models, the stream description should explain the use of input or output multipliers. This it typically a significant part of any model.
  • Ensure that attributes that represent the same thing in different streams have the same name. PhixFlow needs this when processing merges and for a union in a calculate stream.
• Formatting expressions
  • Add comments to document your expression using:
    
    • // for a single line comment
    • /* ... */ to enclose multiline comments
  • Include blank lines between statements
  • Use spaces within expressions
  • Indent sub-clauses by 4 spaces

Naming Conventions

All user-defined variables must start with the $ character. 

• To distinguish between $-variables that are:
  • local use a lowercase first letter, for example $percent
    Local $-variables are only used in the current attribute.

  • global use an uppercase first letter, for example $Percent
     Global $-variables are used in the expressions for other stream attributes.

• For multi-word names, use no spaces and camel case.

Multi-word stream attribute and pipe names should also be in camel case.

Layout for if()

if( condition, Statement 1 , // else Statement 2 )

if( condition, Statement 1, 
// else 
    Statement 2 
)

When there is more than one statement in an if() clause, wrap the statements in a do().

// Example code layout 
if( condition,
    do(
        Statement 1,

        Statement 2,

        .... Statement n
    ),

// else
    Statement A
)

To make it easier to see that statements are correctly bracketed, the closing bracket should always line up with the start of the statement.

Layout for switch()

switch( 
    [ condition expression 1, Statement 1 ], 
    [ condition expression 2, Statement 2 ], 

// default _NULL 
)

The _NULL statement is required.