Add handling for ArrayBuffer data

[rwv]

ArrayBuffer should be exported via some tricky way instead of JSON.stringify.

[Polarisation]

I think it can be done by passing a replace function to JSON.stringify, so it would output something like this:

{
	"IndexedDBExportImport_Type": 'ArrayBuffer',
	"base64": "" // base64 encoded data here
}

[rwv]

I think the point is how to get this thing done gracefully. After adding the type of exported data, you could not simply use JSON.parse(jsonString); to restore the data. Therefore, a export and restore function for each is needed.
exported function maybe like this?

func_dict={
    "ArrayBuffer":{
        "type": ArrayBuffer,
        "func": func_to_exported_arraybuffer,
    }
}

function(data_to_exported) {    
    forEach(func_dict, function(func_item){
        if (data_to_exported instanceof func_item["type"]){
             return {
                 'type': func_item["type"],
                 'data': func_to_exported_arraybuffer(data_to_exported)
             }
        }
    })
    return {
            'type': object,
            'data': JSON.stringify(data_to_exported)
        }
}

[Polarisation]

It should be possible with JSON.parse() using a reviver function

Along with the replacer function for JSON.stringify()

[Polarisation]

I've no plans to work on this but I'd accept a pull request implementing the feature

[rwv]

Sorry, i've no plan to work on this right now but thank you anyway!

[Miaourt]

Hello, kinda digging this up, and It might be a bit out of place, but re-doing https://www.npmjs.com/package/typeson or even using it might be a good solution to handle all the exotic types presents in indexeddb

[Polarisation]

As earlier, I'm happy to accept a pull request but won't be working on this myself.

For people who need this functionality now, there's a Dexie extension, dexie-export-import, that supports a range of types. The main disadvantage is that it's not as lightweight.