What types of result modifiers do we need to support in the search?

[kbrabrand]

These are the result modifiers currently supported by the images resource;

metadata
Whether or not to include metadata in the output. Defaults to 0, set to 1 to enable.

from
Fetch images starting from this Unix timestamp.

to
Fetch images up until this timestamp.

fields[]
An array with fields to display. When not specified all fields will be displayed.

sort[]
An array with fields to sort by. The direction of the sort is specified by appending asc or desc to the field, delimited by :. If no direction is specified asc will be used. Example: ?sort[]=size&sort[]=width:desc is the same as ?sort[]=size:asc&sort[]=width:desc. If no sort is specified Imbo will sort by the date the images was added, in a descending fashion.

ids[]
An array of image identifiers to filter the results by.

checksums[]
An array of image checksums to filter the results by.

originalChecksums[]
An array of the original image checksums to filter the results by.

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metadata, fields are supported by the current metadata search implementation as a consequence of it utilizing the db.images.load event handler for fetching from the backend.

What I want input on is the other modifiers. ids, checksums and originalChecksums I don't really see the need for in the context of the metadata search.

sort is the param I'm thinking we probably want. In order to support sorting like we currently do on the images endpoint, we'll need to store all the image data instead of only the metadata. We would end up with a structure looking like the one used by Imbo in MongoDB for images. The data indexed by the search backend would look like this;

{
    "publicKey" : "publickey",
    "imageIdentifier": "92aa7029b22263ea0b64ba12b4cbf760",
    "size": 1001337,
    "height": 1337,
    "width": 1337,
    "added": 1337001337,
    "metadata": {
        "animal": "Red Panda"
    }
}

I think this is worth the effort, but if people think it's a waist of time I won't care. It would involve;

1. Fetching and passing full image objects to the search backend for indexing whenever the image data (not only metadata) is changed in order to keep it in sync
2. Tweaking the AST -> search DSL transformation slightly in order to build queries using the metadata object.
3. Adding transformation of search parameters to the search backend query building.