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- Another jep expression eg. if( _out.AppleHarvestDate < toDate('20210101'), 1, 0). Here we see an expression within an expression. toDate(converts the string 20210101 into a date 01-01-2021)
- Internal Variables (eg _out.) _out. signals that AppleHarvestDate is being sourced from the same stream you are writing the expression on and that it has already been calculated. Also frequently used is the name of a pipe that goes into a stream followed by a . eg in.AppleHarvestDate which signals that AppleHarvestDate is being sourced down a pipe going into the stream called 'in'. The internal variable preceding an attribute name should reflect where the attribute is being source from. There are many other internal variables, see Internal Variables.
- Regular Expressions - Regular expressions can be used to match patterns within strings or arrays as arguments within jep expressions, for example replaceAll, replaceFirst and matches. See Regular Expressions.
- Simple integers or strings. In the above case 1 and 0 are simple integers. They tell PhixFlow to return the number 1 if NumberOfApples > 1 and 0 if it is not. A string could be returned instead eg. if(_out.NumberOfApples > 1, 'True', 'False') would return the string True if Number Of Apples >1 and False if it is not. Note strings need to be wrapped in ' marks.
Additionally it is good practise to add comments to code to allow other people to understand it. Comments are not evaluated when the code is run. To add a comment start a new line and begin it with */ and end it with *\.
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