Adopting a common, shared, standard layout style for all the scripts that are written expressions, scripts and macros makes it easier to "read" the scripts them and quickly understand what they are doing.
In general, PhixFlow ignores all spacing around the functional elements however . However spacing and layout makes the meaning much clearer for human readers!
This page provides recommended styles for key functional elementswriting expressions.
General
- Add comments (// and /* ... */) to scripts
- Include blank lines between statements
- Use spaces within expressions
- Indent sub-clauses by 4 spaces
- Ensure that attributes which represent the same thing in different Streams, have the same name - this is necessary when doing a Union in a calculate stream but is also important in other types of merge
- Add descriptions to all models
- Add descriptions to all model elements. 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
- .
- All items in PhixFlow have a description property. We recommend you add a description to any item you create.
Naming conventions
Attribute names should be in camel case starting with an Upper Case Letter i.e. upper case letter for every "sub-word". E.g. MainCompanyName
...
- 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
- Add comments to document your expression using:
Naming Conventions
Multi-word stream attribute and pipe names should be in camel case i.e. lower case 1st letter and then an upper case letter for every "sub-word". E.g. $companyOldAddress, inPipe
The names for "global" variables (variables start with a $ character) i.e. variables which have a scope beyond the current expression and are used in subsequent expressions. Global variables should have an upper case first letter e.g. $CompanyLocationCounter.
Layout for if()
if( condition, Statement 1 , // else Statement 2 )
Note that when a statement in an if() clause is more than 1 line, wrap them in a do() e.g.:
if( condition, do ( Statement 1, Statement 2, .... Statement n ) , // else Statement A )
Note that closing brackets should always line up with the start of the statement (see the do() and if() statements above)
Layout for switch()
switch( [ condition expression 1, Statement 1 ], [ condition expression 2, Statement 2 ], // default _NULL )
Note that the _NULL statement is currently required
...
.
Excerpt |
---|
|
Examples | |
---|---|
stream attribute | MainCompanyName |
pipe | inPipe |
global $-variable | $CompanyLocationCounter |
local $-variable | $companyOldAddress |
Tip |
---|
Camel case uses an uppercase letter for the start of each sub-word, for example |
Adding Comments
It is always a good idea to add comments to your scripts to explain its steps. Comments help anyone who needs to modify the script in future.
There are two ways to tell PhixFlow that a line is a comment, and can be ignored.
Notation | Use for |
---|---|
// | short comments up to 1 line |
/* <comment> */ | multi-line comments |
Comments are not evaluated when the code is run.
Code Block | ||
---|---|---|
| ||
/* Get the discount rate that should apply to
the calls that match the filter conditions */
$discountRate = discount.rate,
// Now apply the discount
$value = $value * ( 1 - $discountRate) |
Code Block | ||
---|---|---|
| ||
if(_out.AppleHarvestDate < _toDate('20210101'), 1,
/* Evaluates to 1 if AppleHarvest Date is Before 1st January 2021*/
0
/* and to 0 if it is not */
) |
Layout for if()
if( condition, Statement 1 , // else Statement 2 )
Code Block |
---|
if( condition, Statement 1,
// else
Statement 2
) |
When there is more than one statement in an if() clause, wrap the statements in a do().
Code Block |
---|
// 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()
Code Block |
---|
switch(
[ condition expression 1, Statement 1 ],
[ condition expression 2, Statement 2 ],
// default _NULL
) |
The _NULL statement is required.