使用映射将Grails数据绑定到命令对象-将密钥转换为数字

Question

I have a Grails command object with a list of maps. The map key is intended to be a numeric domain object ID.

class MyCommand {
  def grid = [].withDefault { [:] }
}

Data binding to the list/map is working in general because of the dynamic list expansion.

However, in the POST, the map keys are being bound as Strings and I want them to be Longs, as they are when the form is initially populated. I want foo[123] in my map, not foo['123'] .

Alternatively I would be satisfied if the [] operators found the correct value given a numeric ID key to look up. In other words, if I could get foo[123] to return the same value as foo['123'] , that would work too.

Any way to get this to work the way I want to? Maybe strongly type the map?

Or a better approach?

Answer 1

You can inject the property into the map to convert a String key to Long . For example:

def myMap = [:] << ['1': "name"] << ['Test': "bobo"]
def result = myMap.inject([:]){map, v ->
   def newKey = v.key.isNumber() ? v.key.toLong() : v.key
   map[newKey] = v.value
   map
}

assert myMap['1'] == 'name'
assert result[1L] == 'name'
assert result['Test'] == 'bobo'