Rules and Expressions with Open Weather API

[josh]

@Jason_K_Jennings

• Since the ‘alert’ section won’t always be included in the response, is there an appropriate way to process it only when data exists (maybe an if statement to check to see if it exists before processing it).

If it’s an array, using the map() concept below accounts for this.

Otherwise, using a conditional ternary expression works:

condition ? trueOperation : falseOperation

@Jason_K_Jennings

• Since I wouldn’t know how many values for the ‘alert’ exist (today it is both wind and tornado) – how should I handle this to only process the correct number of ‘events’ that exist in the json file?

Since it’s an array, I would probably use a map() and join() to handle it.

alerts = $context.response.data.alerts
myString = map(alerts, concat(x.event, " until ", formatDate(x.end * 1000, "h:mm a")))
join(myString, "\r\n")

The General Functions in Expressions documentation covers the basics above the above functions or you can search the community as there were a few recent posts about expressions and arrays that may be helpful. This discussion links to a few Array related discussions of interest.

@Jason_K_Jennings

• Is there any way to insert a carriage return into the text?

The \r\n in my example above inserts a new line (Carriage Return / Line Feed). It won’t show up in the variable preview or variable editor, but it will in a notification or a dashboard variable tile.