plugin to add properties to delta

[venelin-mihaylov]

Hi all,
I want to achieve the following:
If I compare two objects with "id" property, and they have differences, in addition of the field differences to add a magic __id property to the diff.
Example:
left:

   {
      id: 1,
      name: 'Philip'
    }

right:

    {
      id: 1,
      name: 'Peter'
     }

The diff that I would get is:

{
   name: ['Philip', 'Peter']
}

I want to get:

{
   __id: 1,
   name: ['Philip', 'Peter']
}

Now, the part that I struggle with:
I want to have __id as part of the diff only if there is a difference between the two objects

I tried with the following plugin:

const diffPluginSaveId = <any> function(context) {
  // I want to add __id and __model
  if (context.leftType === 'object' &&
      typeof context.left.id !== 'undefined'
    // ... ????
  ) {
    console.log(context)
    context.setResult({
      __id: context.right.id,
      __model: context.left.constructor.name
    })
  }
}
diffPluginSaveId.filterName = 'saveId'

const differ = jdp.create(diffConfig)
  differ.processor.pipes.diff.before('collectChildren', diffPluginSaveId)

Please give me a hand :)
Thank you :)

[venelin-mihaylov]

Ok, what about this:

const diffPluginSaveId = <any> function(context) {
  // I want to add __id and __model
  if (context.leftType === 'object' &&
      typeof context.left.id !== 'undefined'
  ) {
    console.log(context)
    const changed =  !!_.find(context.children, (childContext) => childContext.result)
    if (changed) {
      context.setResult({
        __id: context.right.id,
        __model: context.left.constructor.name
      })
    }
  }
}

It seems to work so far.

[vxhly]

Please forgive me for not understanding how you write
There is a setResult here does not appear in the README

[benjamine]

setResult is shown in the example at plugins page (linked in README) https://github.com/benjamine/jsondiffpatch/blob/master/docs/plugins.md#plugin-example