bemusic/bemuse

import * as PIXI from 'pixi.js'

import SkinNode from './lib/base'
import Instance from './lib/instance'
import Expression from '../expression'

export class IfNode extends SkinNode {
  compile(compiler, $el) {
    const children = compiler.compileChildren($el)
    if (children.length !== 1) {
      throw new Error(
        'Expected exactly 1 children, ' + children.length + ' found'
      )
    }
    this.child = children[0]
    this.key = new Expression($el.attr('key'))
    this.value = String($el.attr('value'))
  }

  instantiate(context, container) {
    const object = new PIXI.Container()
    const expr = this.key
    const value = this.value
    const childNode = this.child
    let child = null
    return new Instance({
      context: context,
      parent: container,
      object: object,
      onData: (data) => {
        if (String(expr(data)) === value) {
          if (child === null) {
            child = childNode.instantiate(context, object)
          }
          child.push(data)
        } else {
          if (child !== null) {
            child.destroy()
            child = null
          }
        }
      },
    })
  }
}

export default IfNode