[Backend] Annotation Data Model and Endpoints

[mehmetemreakbulut]

Description:
We started to implement annotation and an API is needed to handle the annotation schema that comes from Frontend. For Posts and Articles we have to store Annotations. Create, Update, Delete and Get functionalities of Annotation will be imlemented.

• W3 Annotation Data Model followed.
• I have implement APIs with respect to payload that comes from Frontend.
• See [Backend] Annotation Data Model #453

Tasks Done:

• Annotation Create and Get Methods
• Annotation Update and Delete Methods
• Annotation Schema mapper
• Unit Tests added

Example Schema for Text Annotation:

{
    "@context": "http://www.w3.org/ns/anno.jsonld",
    "body": [
        {
            "created": "2022-12-17T21:01:59.693Z",
            "creator": {
                "id": "http://3.91.54.225:3000/profile/61",
                "displayName": "Mehmet Emre Akbulut"
            },
            "modified": "2022-12-17T21:01:59.693Z",
            "purpose": "commenting",
            "type": "TextualBody",
            "value": "Content of The Annotation"
        }
    ],
    "id": "#id",
    "target": {
        "selector": [
            {
                "exact": "Exact String Selected",
                "type": "TextQuoteSelector"
            },
            {
                "start": 222,
                "end": 234,
                "type": "TextPositionSelector"
            }
        ]
    },
    "type": "Annotation"
}

Example Schema for Image Annotation:

{
    "@context": "http://www.w3.org/ns/anno.jsonld",
    "body": [
        {
            "created": "2022-12-17T21:01:59.693Z",
            "creator": {
                "id": "http://3.91.54.225:3000/profile/61",
                "displayName": "Mehmet Emre Akbulut"
            },
            "modified": "2022-12-17T21:01:59.693Z",
            "purpose": "commenting",
            "type": "TextualBody",
            "value": "Content of The Annotation"
        }
    ],
    "id": "#b3343k4klRANDOM3434fdfd",
    "target": {
        "selector": {
            "conformsTo": "http://www.w3.org/TR/media-frags/",
            "type": "FragmentSelector",
            "value": "xywh=pixel:491.23232,323.23232,436.8787, 123.4343"
        },
        "source": "URL OF PHOTO"
    },
    "type": "Annotation"
}

Reviewer: @irfanbozkurt

[irfanbozkurt]

I love that you added unit tests. I feel like we're close to our goals. Thanks!