sourceafJson::JsonConverterCtx.fan

** Passed to 'JsonConverters' to them contextual information of the conversion in progress.
@Js
mixin JsonConverterCtx {

    ** A stack of meta objects that represent the contextual parents of converted objects.
    abstract JsonTypeMeta[] metaStack()
    
    ** A stack of Fantom objects that represent the contextual parents of converted objects.
    ** 
    ** Only available when converting *from* Fantom.  
    abstract Obj?[]?        fantomStack()
    
    ** A stack of JSON objects that represent the contextual parents of converted objects.
    ** 
    ** Only available when converting *from* JSON.  
    abstract Obj?[]?        jsonStack()
    
    ** Allows embedded types to be inspected and converted.
    abstract JsonTypeMeta   inspect(Type type)

    ** Returns the current 'JsonTypeMeta' being converted.
    ** Convenience for:
    ** 
    **   syntax: fantom
    **   metaStack.last()
    ** 
    JsonTypeMeta meta() {
        metaStack.last
    }
    
    ** For use by 'JsonConverters' to convert embedded objects. 
    ** The given arguments are pushed on to their corresponding stacks so the conversion that follows may be performed in the proper context.
    Obj? toJson(JsonTypeMeta meta, Obj? fantomObj) {
        metaStack.push(meta)
        fantomStack.push(fantomObj)
        try {
            return meta.converter.toJsonObj(this, fantomObj)
        } finally {
            fantomStack.pop
            metaStack.pop
        }
    }
    
    ** For use by 'JsonConverters' to convert embedded objects. 
    ** The given arguments are pushed on to their corresponding stacks so the conversion that follows may be performed in the proper context.
    Obj? toFantom(JsonTypeMeta meta, Obj? jsonObj) {
        metaStack.push(meta)
        jsonStack.push(jsonObj)
        try {
            return meta.converter.toFantom(this, jsonObj)
        } finally {
            jsonStack.pop
            metaStack.pop
        }       
    }
}

@Js
internal class JsonConverterCtxImpl : JsonConverterCtx {
        JsonTypeInspectors  inspectors
    override JsonTypeMeta[] metaStack
    override Obj?[]?        fantomStack
    override Obj?[]?        jsonStack
    
    new make(|This| f) { f(this) }
    
    override JsonTypeMeta inspect(Type type) {
        inspectors.getOrInspect(type)
    }
}