Multiple key identifiers for API-Platform resources

Question

I have a Chart object which contains a collection of Serie objects and these Serie objects contain collections of Data objects. Instead of requiring a REST API to identify the Serie and Data objects by surrogate primary keys, I wish to do so based on their position within their respective collection.

The database schema is as follows. Originally I considered making serie's chart_id/position and data's chart_id/serie_id/position composite primary keys, however, Doctrine can only do so for one level (i.e. Serie) and to be consistent am using a surrogate keys for all tables.

chart
- id (PK autoincrement)
- name

serie
- id (PK autoincrement)
- position (int with unique constraint with chart_id)
- name
- chart_id (FK)

data
- id (PK autoincrement)
- position (int with unique constraint with serie_id)
- name
- serie_id (FK)
- value

A fully hydrated response for /charts/1 will return the JSON shown below. For instance, to locate the data object whose name is Series1Data1, the url would be /charts/1/series/0/datas/1, or if necessary /datas/chart=1;seriePosition=0;dataPosition=1 would also work.

{
    "id": 1,
    "name": "chart1"
    "series": [{
            "chart": "/chart/1",
            "position": 0,
            "name": "series0.chart1",
            "datas": [{
                    "serie": "/charts/1/series/0",
                    "position": 0,
                    "name": "datas0.series0.chart1"
                }, {
                    "serie": "/series/chart=1;position=0",
                    "position": 1,
                    "name": "datas1.series0.chart1"
                }
            ]
        }, {
            "chart": "/chart/1",
            "position": 1,
            "name": "series1.chart1",
            "datas": []
        }
    ]
}

To change the identifiers, I used @ApiProperty to set identifier for Serie's and Data's primary key $id to false and for Serie's $chart and $position and Data's $serie and $position to true.

Entity/Chart.php

series = new ArrayCollection();
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getSeries(): Collection
    {
        return $this->series;
    }

    public function addSeries(Serie $series): self
    {
        exit(sprintf('Chart::addSeries() $this->series->contains($series): %s', $this->series->contains($series)?'true':'false'));
        if (!$this->series->contains($series)) {
            $this->series[] = $series;
            $series->setChart($this);
        }

        return $this;
    }

    public function removeSeries(Serie $series): self
    {
        if ($this->series->removeElement($series)) {
            if ($series->getChart() === $this) {
                $series->setChart(null);
            }
        }

        return $this;
    }

    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

     public function getName()
    {
        return $this->name;
    }
}

Entity/Serie.php

data = new ArrayCollection();
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getChart(): ?Chart
    {
        return $this->chart;
    }

    public function setChart(?Chart $chart): self
    {
        $this->chart = $chart;

        return $this;
    }

    public function getData(): Collection
    {
        return $this->data;
    }

    public function addData(Data $data): self
    {
        if (!$this->data->contains($data)) {
            $this->data[] = $data;
            $data->setSerie($this);
        }

        return $this;
    }

    public function removeData(Data $data): self
    {
        if ($this->data->removeElement($data)) {
            if ($data->getSerie() === $this) {
                $data->setSerie(null);
            }
        }

        return $this;
    }

    public function setPosition(int $position)
    {
        $this->position = $position;

        return $this;
    }

    public function getPosition()
    {
        return $this->position;
    }

    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

    public function getName()
    {
        return $this->name;
    }
}

Entity/Data.php

id;
    }

    public function getSerie(): ?Serie
    {
        return $this->serie;
    }

    public function setSerie(?Serie $serie): self
    {
        $this->serie = $serie;

        return $this;
    }

    public function setPosition(int $position)
    {
        $this->position = $position;

        return $this;
    }

    public function getPosition()
    {
        return $this->position;
    }

    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

    public function getName()
    {
        return $this->name;
    }
}

API-Platform is able to generate an IRI for the Chart and Serie item, but not for the Data item. I suspect this occurs because Data's $serie identifier property requires both the chartId and its position, but don't know how to resolve it.

I looked into subresources, however, they only support GET requests and subresources will be deprecated in favor of multiple ApiResources (however, I don't even know what "multiple ApiResources" means). Also, maybe related to decorating the IriConverter, but not sure.

What do I need to do to allow the Data resource to be identified by its position in the serie collection, and for the Swagger documentation to reflect doing so?

EDIT - ADDITIONAL CONTENT

I changed the entities in an attempt to implement two different approaches, but unfortunately neither fully work. Should I focus my energies solely on one of the two approaches?

Where the identifier of the parent is in the query (i.e. /datas/chart=1;serie_position=0;data_position=0)
Where the identifier of the parent is in the path(i.e. /charts/1/series/0/datas/0)

If I wanted to use placeholder chart_id instead of id (i.e. /charts/{chart_id}/series/{series_position}/datas/{position} instead of /charts/{id}/series/{series_position}/datas/{position}, how can I remove or rename chart's id?

Should I be doing this differently so I don't need all the annotations and maybe rename chart's id? To some degree I was able to get Swagger to provide the fields, but don't think I am doing it right. Maybe by decorating api_platform.openapi.factory?

user_382655 · Answer

Sadly I've found that api-platform is too-naive and very limiting for designing/implementation of good multilevel api (and api resources that generally do not conform the entities stored in ORM) and leads to unreadable/unmaintainable code really fast.

For similar use case I've resorted to a single api endpoint with three required parameters (not to mention that api-platform got removed from the project month and a half later).

Multiple key identifiers for API-Platform resources

1 Answers