Allowing NULL in JSON Schema removes item from Dynamic Content list

[Ben_Love]

I have a Request trigger which in turn passes through a Parse JSON action. JSON schema was originally created using the 'Use sample payload to generate schema button. All worked well until I discovered that due to the payload being delivered to this trigger I needed to allow NULLs for some values within my JSON schema. Once this change was made to my schema, a number of items from the available Dynamic Content list from my Parse JSON action disappeared. Removing the 'allow NULL' config from the JSON schema and the Dynamic Content values return to the available list. 

Specifically I have verified this on JSON type 'Array' and 'String'. I haven't bothered testing other types at this stage. I have attached two screenshots showing with and without the NULL allowed in the schema. 

I believe this to be a bug, as we still need to work with the defined values, irrespective of whether the JSON schema allows NULL values. 

[v-yamao-msft]

Hi Ben_Love,

I am afraid JSON schema would not allow Null value.

Please consider to replace the Null value with some string.

I have seen a similar one on Flow Ideas Forum, please consider to vote and comment the idea at here. I will also collect and report it on my side.

https://powerusers.microsoft.com/t5/Flow-Ideas/Support-null-in-Parse-JSON/idi-p/41182

Best regards,
Mabel Mao

[Ben_Love]

Hi Mabel,

Thanks for your reply. The JSON Schema definition obviously allows for NULL values to be passed, so I assume that you are saying that specifically the Parse JSON Action in Flow does not support NULL values? Is that correct? 

This seems like a significant oversight. 

Given that we have no control over the system generating the JSON payload, and must simply work with what we're given, how do you suggest I convert the NULL values to something else? 

Ben

[DanITman]

I can confirm that this bug exists.  MS should fix this.

I had to remove the null type and then insert the field into my condition.  I then went back in and changed the schema to allow for null and all was good. 

[Vinicius]

Hello guys,

When i add property "null" into my json schema, i can't use the converted fields in a next step of my flow. Anyone can help me?

Thx!!