How to flatten nested JSON?

Hi @cheffing,

You can use the JSON reader, (or a JSONFlattener set to read from file) to read the JSON records from the file and flatten the attribute structure.

However, the resulting attributes will mostly be lists, which cannot be written to Shape files, so you will need to explode these lists into individual features. The simplest way to do this is to explode the timeslices list with a ListExploder, then use ListIndexers to get the matching data from the other lists, using the index attribute produced by the ListExploder.

I am attaching a workspace to illustrate the process.

json2shape.fmw

Hi @cheffing,

I think you have two options here:

a) Save this JSON response from the API request to a file and then use a FeatureReader to read it in - this will flatten the JSON for you and return all these attributes without a need for you to build any JSON Queries.

b) If the JSON response is coming in from an attribute use a JSONFragmenter, leave the JSON Query as json[*] and then under Flattening Parameters set Flatten Query Result into Attributes = Yes and under Attributes to Expose add the names of all your attributes. A number of your attributes:

• timeslice
• WIND_6H
• RISK_WINDBREAKAGE_BEECH_MAX_6H
• RISK_WINDBREAKAGE_SPRUCE_MAX_6H
• PROB_GUST_100kmh_MAX_6H
• PROB_GUST_75kmh_MAX_6H
• PROB_GUST_60kmh_MAX_6H

are actually lists so when you add these you will need to specify {} for these to be exposed. E.g. timeslice{} and then you can explode these into actual attributes.