Help with JSONTemplater - Sub Templates & Arrays

Question

I am trying to generate a JSON message to update editing templates on an AGOL Feature Service. I've got most of it complete. I am having trouble with the last piece though.

Each Editing Template has a list of fields and defaults like this:

JSONIssue_Screenshot1 I am trying to generate 27 unique editing templates based on unique pairs of 2 attributes. The portion of the JSON text I am struggling with is the ["types"]["templates"]["prototype"]["attributes"] section. I have the correct number of "types" (27). I have the correct fields and corresponding default values.

JSONIssue_CurrentResults As you can see, I am getting an extra pair of "},{" between each field as compared to the example above. Almost like each row is it's own unique element. I am sending 594 features into the "EDITEMPLATEFIELDS" sub template and grouping the process by '_editTemplatePairs' attribute as these contain 27 unique field configurations for all 22 fields in the editing template.

I am leveraging Sub Templates in the JSONTemplater. Here's how I currently have this section set up:

ROOT: (Number of Incoming Features: 1)

JSONIssue_JSONTemplator_ROOT Sub Template: EDITTYPES (Number of Incoming Features: 27)

JSONIssue_JSONTemplator_SUB_EDITTYPES Sub Template: EDITEMPLATEFIELDS (Number of Incoming Features: 594)

JSONIssue_JSONTemplator_SUB_EDITEMPLATEFIELDS I can't seem to get the JSONTemplator to ignore the 'array' function. Ultimately, I have 27 different variations of these sets of fields:

JSONIssue_ExampleOfFields Any suggestions on how to remove the 'Array' syntax in the ["prototype"]["attributes"] section? I've tried playing around with lists and pre-formatting JSON text, but have gotten no where. I'm sure I'm missing some very simple here.

Unfortunately, I won't be able to upload my workspace as the services I am trying to update cannot be shared publicly.

FME Version: 2020.1.3.0 (20201001 - Build 20632)

Thanks in advance!

-Mark

virtualcitymatt · Accepted Answer

Not a real solution exactly, however, something that I find quite helpful is a combination of an attribute creator to built the strings so:

_attribute = "@Value(_jsonPrototype_AttributeName)" : "@Value(_jsonPrototype_AttributeValue)"

This will give you an attribute formatted for one line of the json.

Next use an Aggregator to combine the attributes into a single string blob:

Attributes to concatenate: _attribute

Separator Character: ,\\n (where "\\n" is a new line character available in the Special Characters section in the text editor)

You'll then have a blob of text formatted inside one attribute that you can just stick in.

It's not exactly a clean method or elegant but it should work as a quick work around.

The Json and xml templators are really powerful but there seems to be a lot of hidden undocumented features, sometimes a workaround is the quickest approach until you learn how to do it the 'proper' way

mmccart · Answer

Not a real solution exactly, however, something that I find quite helpful is a combination of an attribute creator to built the strings so:

_attribute = "@Value(_jsonPrototype_AttributeName)" : "@Value(_jsonPrototype_AttributeValue)"

This will give you an attribute formatted for one line of the json.

Next use an Aggregator to combine the attributes into a single string blob:

Attributes to concatenate: _attribute

Separator Character: ,\\n (where "\\n" is a new line character available in the Special Characters section in the text editor)

You'll then have a blob of text formatted inside one attribute that you can just stick in.

It's not exactly a clean method or elegant but it should work as a quick work around.

The Json and xml templators are really powerful but there seems to be a lot of hidden undocumented features, sometimes a workaround is the quickest approach until you learn how to do it the 'proper' way

@virtualcitymatt Thanks! That's a nice little trick to add to my bag. I modified it a little. Like you said, not pretty, but gets the results I need. I'm sure there is a more elegant way to get to the same endpoint.

I'm documenting my final solution here in case someone else runs into the same issue:

First, I had to account for empty/null attributes. I used a conditional statement when creating the '_attributes' attribute that was mentioned above. Here's what I did:

JSONIssue_Fix_ConditionalStatement Next, in the aggregator, I had to set the GroupBy parameter and I did not include the "\\n" in the Separator Character like this:

JSONIssue_Fix_AggregatorSettings Next, I had to append a "{" to the beginning of the aggregator output and a "}" to the end of the same output like this in an AttributeCreator as the JSONTemplater wasn't putting them in the correct position.

JSONIssue_Fix_AddBrackets The final JSON text looks like this before going to the JSON Templater:

JSONIssue_Fix_FinalTextBeforeJSONTemplater Next, I modified the "EDITTYPES" & "EDITTEMPLATEFIELDS Sub Templates in the JSONTemplater as shown below:

JSONIssue_Fix_ChangeToSubTemplate-EDITTYPES The final result looks like this:

JSONIssue_Fix_Results Thanks again for your help @virtualcitymatt Hopefully this helps someone else dealing with the unique JSON formatting of feature services.

Help with JSONTemplater - Sub Templates & Arrays

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