mutators in json definition

[Bart Butenaers]

Hi everybody,

I want to convert all my block definitions to JSON format, but now I'm stuck on the SWITCH block that I used from this link.

In that Block two mutators (?) are defined:

this.setMutator(new Blockly.Mutator(['case_incaseof','case_default']));

However if I want to convert that to JSON, I see this in the documentation: 

Mutators are the only way to provide custom serializable state on a block. 

They are declared on a block's JSON definition using the mutator key. 

Only one mutator may be declared on a block.

{
  //...,
  "mutator": "controls_if_mutator",
}

Is it possible to do this in JSON?

Thanks again !!

Bart

[Bart Butenaers]

Hi folks,

case closed.  I misunderstood the concept entirely.  Seems that it is a single mutator that we need to pass the two sub-blocks it will use in this case.

For anybody ever making the same stupid mistake, here is what I did (I used the mutator code of this one):

1. Created a mutator object will all the required functions:

const switchCaseMutator = {
  mutationToDom: function() {
    ...
  },

  domToMutation: function(xmlElement) {
   ...
  },

 ...
};

 2. Register this mutator object, with fourth parameter an array of all sub-objects used in the mutator:

Blockly.Extensions.registerMutator('switch_case_mutator', switchCaseMutator, null, ['case_incaseof', 'case_default']);

3. At least use the "mutator" in the JSON definition of your block:

Blockly.Blocks['switch_case'] = {
    init: function() {
       
        this.jsonInit({
            "type": "switch_case",
            "mutator":["switch_case_mutator"],
            "colour": "#5C81A6",
            "tooltip": Blockly.Msg.SWITCH_TOOLTIP,
            "helpUrl": null
        });
}}

Then it seems to be working fine ...

Bart