Querying workflow instances by variables

[asaf]

Support querying workflow instances by specific variables names & values.

[saig0]

Sounds interesting 👍

Do you have an idea of how the GraphQL query/schema should look like?

[asaf]

it's a bit challenging with GraphQL as it requires static definitions of the args,
the easiest way would be to find some filter string that can be easily converted to JPA query or just provide extra sql clause (need to be careful with injections though)

maybe we can do something in the form of:

{
    variables(filter: "foo == \"bar\" and bar != null") {
      name
      value
    }
}

[saig0]

A query string sounds like a simple way. But passing a SQL/JPA query as filter argument feels not right 😅

What do you think about something like the following?

{
  variable(filter: { name: "foo", value_eq: "bar"}) {
    name
    value
  }
}

So, the workflow instances would be collected by the variables.

{
  variable(filter: { name: "foo", value_eq: "bar"}) {
    name
    value

    scope {
      workflowInstance {
        key
      }
    }
  }
}

Does this work for you?

[asaf]

@saig0 i think that this syntax restricts a single filter condition, i would make filter an array if possible for multi conditions

[saig0]

Ok. Let's try to make it as simple as possible (because filtering can get complicated 😅).

Which queries do you need exactly?

[asaf]

@saig0 i don't have specific demands atm, it was more a suggestion for your project :)

[saig0]

We can give it a try and see how it works out. We should start with a filter for variables first that allow filtering by a variable name and a value. The value must match exactly to make it easy.

[aanodin]

@saig0 @asaf any updates on this? We are looking for that feature too.
To be more specific, we have an order management system that creates many workflow instances, one instance for one order.
Lets say we have a variable "order" in each our process instance:

{
  "customer": {
    "msisdn": "123456789",
    "name": "John"
  },
  "items": [
	{
		"name": "some product 1",
                "quantity": 1
	},
	{
		"name": "some product 2",
                "quantity": 2
	}	
  ]
}

Now we want to find all processes created by the same customer. At this point we can't know how exact json of each order looks. What we need to do is to find them all using a filter like "order.customer.msisdn": "123456789".

There is an example of how such GraphQL model can be implemented: https://chillicream.com/docs/hotchocolate/v12/integrations/mongodb#filtering
This is how HotChocolate (GraphQL implementation for .NET) interacts with MongoDB databases, transforming GraphQL queries into native MongoDB ones.

query GetPersons {
  persons(
    where: {
      name: { eq: "Yorker Shorton" }
      addresses: { some: { street: { eq: "04 Leroy Trail" } } }
    }
  ) {
    name
    addresses {
      street
      city
    }
  }
}

[saig0]

@aanodin no updates so far. Currently, I don't need this feature at the moment. So, I don't plan to implement something like this soon.

Your request is also more complicated than the initial one. Instead of finding a variable based on a concrete value, you want to find a variable (i.e. the process instance) based on a partial JSON value.

I'm not sure how we could implement this query based on JPA. ZeeQS is not bound to a specific database. Maybe, QueryDSL could help here, but not sure how far.

[shahamit]

We hit through this use case too. I am new to graphql a bit. @saig0 - could you please elaborate what would it mean to support such kind of filter queries in zeeqs? What kind of code changes are required?

[saig0]

@shahamit you can have a look at the following examples:

• process instance query filters by state using an option function parameter
• process instance subscription filters by process key using an input type

From the code perspective, you would need to:

• extend the GraphQL definition
• implement the query resolver
• extend the repository
• write a few test cases