[BUG] minimum age gets melted into node API in query

[surchs]

Is there an existing issue for this?

• I have searched the existing issues

Expected Behavior

I can run a query for a single node and define a minimum age

Current Behavior

if I set sex, all is well: https://federate.neurobagel.org/query/?&node_url=https://api.neurobagel.org/&sex=snomed:248153007

if I set minimum age, this happens: https://federate.neurobagel.org/query/?&node_url=https://api.neurobagel.org/min_age=1

Error message

federation API rightly complains that

"Unrecognized Neurobagel node URL(s): ['https://api.neurobagel.org/min_age=1/']

Environment

• any single or multiple node selection except "All"

How to reproduce

1. Select any node other than "All"
2. define a minimum age
3. watch it break with "Oops"

Anything else?

see also OpenNeuroOrg/openneuro#2807

most likely this is our culprit:
https://github.com/neurobagel/query-tool/blob/dadbee332c593f95f5bab9bc037837f2241a6f76/components/QueryForm.vue#L222-L227

i.e. we do not concatenate min_age correctly.

The reason this doesn't break for the "All" node is that we encode "All" as "no node parameter set":

https://federate.neurobagel.org/query/?min_age=1

so in this very specific case, min_age actually is the first query parameter and gets parsed correctly. This is most likely a leftover thing from when a query tool only ever talked directly to a node API and the federation API didn't exist yet.

[surchs]

Options we have here:

• be more smart about when we prefix a query parameter with &, i.e. only if it follows a previous parameter
• add & everytime. It's not "proper" but it is valid 🤷

[rmanaem]

I wonder if there is a library we can use that allows us to pass params as an object something similar to params of httpx.get we use in federation-api.

[surchs]

you mean as part of a post body as opposed to the get we use here? Is that used somewhere else already?
For this specific bug, we need to make sure we only pass min_age without a leading & if we're certain that it is the first query parameter. This used to be always the case, but now the node query parameter can be before min_age whenever any node is selected except "All"