You could generate the list of strings in your workspace and then define the output attribute as a pre-defined json block:

In you case, dct_license_sm could contain e.g. the following valid JSON list:

["https://creativecommons.org/licenses/by/4.0/"]

["https://creativecommons.org/licenses/by/4.0/"]

Isn't that a bit complicated?  Do you know why FME doesn't respect the datatype? 

Strictly speaking, an array of strings is comprised of two data types ;-)

But you can also do something like this:

In my case {0} = 'abc' and {1} = 'def'.

Result:

[
	{
		"json_featuretype" : "NewFeatureType",
		"dct_license_sm" : [ "abc", "def" ]
	}
]

Hello, would anyone have a sample workbench that they could upload to illustrate this please? Im having terrible trouble getting a postgis table to export into a pre-defined json schema. I dont understand it at all - especially the part about putting some data into a list.
Worked example would be fab if poss?  xx

Hi ​@sar_copp 

We have a JSON tutorial series that may help: Tutorial: Getting Started with JSON the tutorial series includes some sample workspaces. 

We also have a webinar on this topic Optimizing XML & JSON Workflows for Seamless Data Integration with a related demo in the Transformer Comparison section starting at around minute 18. 

Hope this helps! 

Hello ​@crystalatsafe Ive watched the webinar you linked which was helpful and I need to try out the json templater in more depth. I didnt find the getting started tutorial super helpful because I have zero understanding about json- why cant everything just be in a structured table format (haha). The issue is that whilst we have a json schema to follow, the outputs are quite dynamic, dependent on the type of record in the table (all the same table). Does the json templater allow for this?

e.g. 1)  No Waiting At Any Time Traffic Restriction (i.e. double yellow lines) will have to have certain items in the json output file.

2. Weight Restriction for a road (e.g. 3 tonnes limit on a road) will need to produce a completely different set of items in the json output for that record.

Ive attached 2 examples in the Zip file, is this even possible what Im trying to achieve?

Great tutorial ​@crystalatsafe 

Anyone else got any wisdom, this is proving frustratingly difficult.

Hi ​@sar_copp 

Can you create a separate post with a sample of the input feature for both cases you mentioned and the expected output from those sample features? Creating a new post will increase visibility in the community so more people will be able to see it.

Generally, it is possible to use conditionals with a JSONTemplater. It can be done within the XQuery in the JSONTemplater using an if-then-else statement (example here) or possibly using a Tester/TestFilter with subtemplates in the JSONTemplater.