Draft: Filtering Collections

[Elias23]

Based on the described solution in the issue thread resolves #334. Have not yet implemented a fix for the Date problem.

[torshid]

There are some serious changes in the original solution provided by @zhenyabodukhin. Would like to know how these performed since then. Unit tests will make the thing perfect I guess.

[zhenyabodukhin]

@torshid Only wrap arrays if there exists in filter not enough. You should combine them like this:
"$anyElementTrue": {
"$map": {
"input": {
"$ifNull": [
"$tasks",
[]
]
},
"in": {
"$anyElementTrue": {
"$map": {
"input": {
"$ifNull": [
"$$this.groupRecipient",
[]
]
},
"in": {
"$and": [
{
"$eq": [
"$$this.tenantId",
{
"$uuid": "4ec6e247-895f-47fa-b427-cecf2ac0f54f"
}
]
},
{
"$eq": [
"$$this.groupName",
"PLATFORM_OPERATOR"
]
},
{
"$anyElementTrue": {
"$map": {
"input": {
"$ifNull": [
"$$this.roles",
[]
]
},
"in": {
"$and": [
{
"$isArray": [
[
"ORDER_MANAGER"
]
]
},
{
"$in": [
"$$this",
[
"ORDER_MANAGER"
]
]
}
]
}
}
}
}
]
}
}
}
}
}
}

I added cache to TransformerUtils, but its not works if you have similar paths in filter (only first will be applied). I can post my solution if it necessary.

[zhenyabodukhin]

@torshid Check last commit.
https://github.com/zhenyabodukhin/springfilter/tree/bug/nested-search-mongo

[zhenyabodukhin]

For example “tasks.text: ‘value1’ and tasks.text: ‘value2’” will not work. In this case you can refactor like this “tasks.text in [‘value1’, ‘value2’]” and it will work. But if we have like this “tasks.date:> ‘value1’ and tasks.date:< ‘value2’” will not work and this is a problem. In my project we escape this case, but for you this is bad solution :)
When i sad “combine” i mean combine by arrays path.

[zhenyabodukhin]

I guess problem with same paths in filter is appear because i cache nodes and in wrapArrays methods i invokes method transform(), so again invokes wrapArrays and cache not work properly. So i added processedPath to solve this problem, as a result we have issue with same paths. I think if we has opportunity not to use transform() in arrayPaths() this problem will be solved.

[Elias23]

In my case I don't have nested Collections, which simplifies the issue for me. I added a post-processing stage to the filter generation, which flattens out nested and and or. Afterward, I merge the paths in the same and/or block if the mapping matches. I added some simple tests.

[Elias23]

Not sure how to provide an integration test like proof that it works for simple collections.
Here is an example:
filter: active=false and groupMemberships.entryDate= '1951-12-03T00:00:00Z' and groupMemberships.leavingDate= '1955-12-04T00:00:00Z'
result:

{
    "$expr": {
        "$and": [
            {
                "$eq": [
                    "$active",
                    false
                ]
            },
            {
                "$anyElementTrue": {
                    "$map": {
                        "input": {
                            "$ifNull": [
                                "$groupMemberships",
                                []
                            ]
                        },
                        "as": "this",
                        "in": {
                            "$and": [
                                {
                                    "$eq": [
                                        "$$this.entryDate",
                                        {
                                            "$date": {
                                                "$numberLong": "-570585600000"
                                            }
                                        }
                                    ]
                                },
                                {
                                    "$eq": [
                                        "$$this.leavingDate",
                                        {
                                            "$date": {
                                                "$numberLong": "-444268800000"
                                            }
                                        }
                                    ]
                                }
                            ]
                        }
                    }
                }
            }
        ]
    }
}