diff --git a/src/app/app.ts b/src/app/app.ts
index a5c638e6..f323c857 100644
--- a/src/app/app.ts
+++ b/src/app/app.ts
@@ -2,6 +2,8 @@ import { RootNode } from '../nodes/RootNode'
 import { EnumNode } from '../nodes/EnumNode'
 import { ObjectNode } from '../nodes/ObjectNode'
 import { StringNode } from '../nodes/StringNode'
+import { DataModel } from '../model/DataModel'
+
 
 const EntityCollection = ['sheep', 'pig']
 
@@ -13,14 +15,12 @@ const predicateTree = new RootNode('predicate', {
     type: new EnumNode(EntityCollection, {}),
     nbt: new StringNode()
   })
+}, {
+  default: () => ({ condition: 'foo', predicate: { nbt: 'hi' } })
 });
 
-let dummyData = {
-  condition: 'foo',
-  predicate: {
-    nbt: 'hi'
-  }
-}
+const model = new DataModel(predicateTree)
 
-document!.getElementById('view')!.innerHTML = predicateTree.render('', dummyData)
-document!.getElementById('source')!.textContent = predicateTree.transform(dummyData)
+model.render(document!.getElementById('view')!)
+
+// document!.getElementById('source')!.textContent = predicateTree.transform(dummyData)
diff --git a/src/model/DataModel.ts b/src/model/DataModel.ts
new file mode 100644
index 00000000..0f0ed496
--- /dev/null
+++ b/src/model/DataModel.ts
@@ -0,0 +1,38 @@
+import { RootNode } from "../nodes/RootNode"
+import { Path } from "./Path"
+
+type Registry = {
+  [id: string]: (el: Element) => void
+}
+
+const registryIdLength = 12
+const dec2hex = (dec: number) => ('0' + dec.toString(16)).substr(-2)
+
+export function getId() {
+  var arr = new Uint8Array((registryIdLength || 40) / 2)
+  window.crypto.getRandomValues(arr)
+  return Array.from(arr, dec2hex).join('')
+}
+
+export class DataModel {
+  private data: any
+  private schema: RootNode
+  private registry: Registry = {}
+
+  constructor(schema: RootNode) {
+    this.schema = schema
+    this.data = schema.default
+  }
+
+  register(id: string, callback: (el: Element) => void) {
+    this.registry[id] = callback
+  }
+
+  render(target: HTMLElement) {
+    target.innerHTML = this.schema.render(new Path(), this.data, this)
+    for (const id in this.registry) {
+      const element = target.querySelector(`[data-id="${id}"]`)
+      if (element !== null) this.registry[id](element)
+    }
+  }
+}
diff --git a/src/model/Path.ts b/src/model/Path.ts
new file mode 100644
index 00000000..14ece07a
--- /dev/null
+++ b/src/model/Path.ts
@@ -0,0 +1,26 @@
+
+type PathElement = (string | number)
+
+export class Path {
+  private arr: PathElement[]
+
+  constructor(arr?: PathElement[]) {
+    this.arr = arr || []
+  }
+
+  last(): PathElement {
+    return this.arr[this.arr.length - 1]
+  }
+
+  pop(): Path {
+    return new Path(this.arr.slice(0, -1))
+  }
+
+  push(element: PathElement): Path {
+    return new Path([...this.arr, element])
+  }
+
+  copy(): Path {
+    return new Path([...this.arr])
+  }
+}
diff --git a/src/nodes/AbstractNode.ts b/src/nodes/AbstractNode.ts
index e297410c..c2b20b88 100644
--- a/src/nodes/AbstractNode.ts
+++ b/src/nodes/AbstractNode.ts
@@ -1,23 +1,28 @@
+import { DataModel, getId } from "../model/DataModel"
+import { Path } from "../model/Path"
 
 export interface INode<T> {
   setParent: (parent: INode<any>) => void
   transform: (value: T) => any
-  render: (field: string, value: T) => string
+  render: (path: Path, value: T, model: DataModel) => string
 }
 
-export interface NodeChildren {
+export type NodeChildren = {
   [name: string]: INode<any>
 }
 
-export interface NodeMods<T> {
+export type NodeMods<T> = {
+  default?: () => T
   transform?: (value: T) => any
 }
 
 export abstract class AbstractNode<T> implements INode<T> {
-  private transformMod = (v: T) => v
-  protected parent?: INode<any>
+  parent?: INode<any>
+  default?: T
+  transformMod = (v: T) => v
 
   constructor(mods?: NodeMods<T>) {
+    if (mods?.default) this.default = mods.default()
     if (mods?.transform) this.transformMod = mods.transform
   }
 
@@ -25,9 +30,24 @@ export abstract class AbstractNode<T> implements INode<T> {
     this.parent = parent
   }
 
+  wrap(path: Path, model: DataModel, renderResult: string): string {
+    const id = getId()
+    model.register(id, el => {
+      console.log(`Callback ${id} -> ${path.last()}`)
+      this.mounted(el, path, model)
+    })
+    return `<div data-id="${id}">${renderResult}</div>`
+  }
+
+  mounted(el: Element, path: Path, model: DataModel) {
+    el.addEventListener('change', evt => this.updateModel(el, path, model))
+  }
+
+  updateModel(el: Element, path: Path, model: DataModel) {}
+
   transform(value: T) {
     return this.transformMod(value)
   }
 
-  abstract render(field: string, value: T): string  
+  abstract render(path: Path, value: T, model: DataModel): string  
 }
diff --git a/src/nodes/EnumNode.ts b/src/nodes/EnumNode.ts
index d2a56152..452f971c 100644
--- a/src/nodes/EnumNode.ts
+++ b/src/nodes/EnumNode.ts
@@ -1,4 +1,6 @@
 import { AbstractNode, NodeMods } from './AbstractNode'
+import { DataModel } from '../model/DataModel'
+import { Path } from '../model/Path'
 
 export class EnumNode extends AbstractNode<string> {
   protected options: string[]
@@ -8,10 +10,13 @@ export class EnumNode extends AbstractNode<string> {
     this.options = options
   }
 
-  render (field: string, value: string) {
-    return `<span>${field}</span>
+  updateModel(el: Element, path: Path, model: DataModel) {
+  }
+
+  render(path: Path, value: string, model: DataModel) {
+    return this.wrap(path, model, `<span>${path.last()}</span>
     <select value="${value}">
       ${this.options.map(o => `<option>${o}</option>`)}
-    </select>`
+    </select>`)
   }
 }
diff --git a/src/nodes/ObjectNode.ts b/src/nodes/ObjectNode.ts
index d34ebd5d..c47c2446 100644
--- a/src/nodes/ObjectNode.ts
+++ b/src/nodes/ObjectNode.ts
@@ -1,4 +1,6 @@
 import { AbstractNode, NodeChildren, NodeMods } from './AbstractNode'
+import { DataModel } from '../model/DataModel'
+import { Path } from '../model/Path'
 
 export interface IObject {
   [name: string]: any
@@ -15,10 +17,6 @@ export class ObjectNode extends AbstractNode<IObject> {
     })
   }
 
-  getFields() {
-    return this.fields
-  }
-
   transform(value: IObject) {
     if (value === undefined) return undefined
     value = value || {}
@@ -29,12 +27,12 @@ export class ObjectNode extends AbstractNode<IObject> {
     return res;
   }
 
-  render(field: string, value: IObject) {
+  render(path: Path, value: IObject, model: DataModel) {
     if (value === undefined) return ``
-    return `<span>${field}:</span><div style="padding-left:8px">
+    return this.wrap(path, model, `<span>${path.last()}:</span><div style="padding-left:8px">
       ${Object.keys(this.fields).map(f => {
-        return this.fields[f].render(f, value[f])
-      }).join('<br>')}
-    </div>`
+        return this.fields[f].render(path.push(f), value[f], model)
+      }).join('')}
+    </div>`)
   }
 }
diff --git a/src/nodes/RootNode.ts b/src/nodes/RootNode.ts
index 75758641..c84df6ca 100644
--- a/src/nodes/RootNode.ts
+++ b/src/nodes/RootNode.ts
@@ -1,10 +1,12 @@
 import { NodeChildren, NodeMods } from './AbstractNode'
 import { ObjectNode, IObject } from './ObjectNode'
+import { Path } from '../model/Path'
+import { DataModel } from '../model/DataModel'
 
 export class RootNode extends ObjectNode {
-  private id: string
+  id: string
 
-  constructor(id: string, fields: NodeChildren, mods?: NodeMods<any>) {
+  constructor(id: string, fields: NodeChildren, mods?: NodeMods<IObject>) {
     super(fields, mods)
     this.id = id
   }
@@ -13,12 +15,12 @@ export class RootNode extends ObjectNode {
     return JSON.stringify(super.transform(value))
   }
 
-  render(field: string, value: IObject) {
+  render(path: Path, value: IObject, model: DataModel) {
     value = value || {}
     return `<div>
       ${Object.keys(this.fields).map(f => {
-        return this.fields[f].render(f, value[f])
-      }).join('<br>')}
+        return this.fields[f].render(path.push(f), value[f], model)
+      }).join('')}
     </div>`
   }
 }
diff --git a/src/nodes/StringNode.ts b/src/nodes/StringNode.ts
index 9c033166..7ebb8f21 100644
--- a/src/nodes/StringNode.ts
+++ b/src/nodes/StringNode.ts
@@ -1,11 +1,17 @@
 import { AbstractNode, NodeMods } from './AbstractNode'
+import { Path } from '../model/Path'
+import { DataModel } from '../model/DataModel'
 
 export class StringNode extends AbstractNode<string> {
   constructor(mods?: NodeMods<string>) {
     super(mods)
   }
 
-  render(field: string, value: string) {
-    return `<span>${field}</span> <span>${value || ''}</span>`
+  updateModel(el: Element, path: Path, model: DataModel) {
+  }
+
+  render(path: Path, value: string, model: DataModel) {
+    return this.wrap(path, model, 
+      `<span>${path.last()}</span> <input value="${value || ''}"></input>`)
   }
 }