diff --git a/demo/demos/WithHandlersDemo.tsx b/demo/demos/WithHandlersDemo.tsx
new file mode 100644
index 0000000..24f972b
--- /dev/null
+++ b/demo/demos/WithHandlersDemo.tsx
@@ -0,0 +1,32 @@
+import * as React from 'react';
+import { withState } from '../../src/lib/withState';
+import { ChainableComponent } from '../../src/ChainableComponent';
+import Step from '../Step';
+import { DoBuilder } from '../../src';
+import { withHandler } from '../../src/lib/withHandler';
+
+export const WithHandlersDemo =
+  DoBuilder
+    .bind('b', withState(0))
+    .bind('a', withState(0))
+    .bindL('handler', ({a, b}) => {
+      console.log('handler', a.value, b.value)
+      return withHandler(() => alert(`A's count is : ${a.value}`), [b.value])
+    })
+    .done()
+    .render(({a, b, handler}) => (
+      <div>
+        <div>a: {a.value} <button onClick={() => a.update(a.value + 1)}>+</button></div>
+        <div>b: {b.value} <button onClick={() => b.update(b.value + 1)}>+</button></div>
+        <button onClick={handler}>alert</button>
+      </div>
+    ))
+
+export default () => (
+  <Step title="WithHandlersDemo Demo">
+    <pre className='code-sample'>
+      {``}
+    </pre>
+    {WithHandlersDemo}
+  </Step>
+);
diff --git a/src/Dependencies.ts b/src/Dependencies.ts
new file mode 100644
index 0000000..7db7065
--- /dev/null
+++ b/src/Dependencies.ts
@@ -0,0 +1,37 @@
+
+type Dependency<A> = {
+    _type: '@@ChainableComponentsDependency',
+    value: A,
+    equals: (l: A, r: A) => boolean
+}
+
+function isDep<T>(a: any): a is Dependency<T> {
+    return a.type === '@@ChainableComponentsDependency'
+}
+
+type Dependencies = (any | Dependency<any>)[]
+
+export function equals(l: Dependencies, r: Dependencies): boolean {
+    return l.every((dep, i) => {
+        const rightDep = r[i]
+        if(isDep(dep)) {
+            if(isDep(rightDep)) {
+                return dep.equals(dep.value, rightDep.value)
+            } else {
+                return false;
+            }
+        } else {
+            return dep === rightDep;
+        }
+    })
+}
+
+export function itemEquals(l: any, r: any): boolean {
+    if(l && isDep(l) ) {
+    }
+    return l.equals(l.value, r.value)
+}
+
+export function depEquals<A>(l: Dependency<A>, r: Dependency<A>): boolean {
+    return l.equals(l.value, r.value)
+}
diff --git a/src/lib/withHandler.ts b/src/lib/withHandler.ts
new file mode 100644
index 0000000..d8c4d5b
--- /dev/null
+++ b/src/lib/withHandler.ts
@@ -0,0 +1,14 @@
+import { ChainableComponent } from '../ChainableComponent';
+import { withLifecycle } from './withLifecycle';
+import { equals } from '../Dependencies';
+
+export function withHandler<F extends Function>(
+  cb: F,
+  dependencies: any[]
+): ChainableComponent<F> {
+  return withLifecycle<[F, any[]]>({
+    init: () => [cb, dependencies],
+    deriveContext: ([f, deps]) =>
+      equals(deps, dependencies) ? [f, deps] : [cb, dependencies]
+  }).map(a => a[0]);
+}
diff --git a/src/lib/withLifecycle.ts b/src/lib/withLifecycle.ts
index 435b082..948e2b3 100644
--- a/src/lib/withLifecycle.ts
+++ b/src/lib/withLifecycle.ts
@@ -10,39 +10,69 @@ import {
  * Configuration for the withLifecycle chainable component
  */
 export type WithLifecycleOptions<C> = {
-  componentDidMount: () => C;
-  componentWillUnmount?: (c: C) => void;
+  init: () => C;
+  componentDidMount?: (c: C) => C;
+  componentWillUnmount?: (c: C) => C;
+  deriveContext?: (c:C) => C;
+  componentWillUpdate?: (c: C) => C;
   shouldComponentUpdate?: (c: C) => boolean;
 };
 
-type WithLifecycleProps<C> = RenderPropsProps<WithLifecycleOptions<C>, {}>;
+type WithLifecycleProps<C> = RenderPropsProps<WithLifecycleOptions<C>, C>;
+
+const iff = <A>(a: A | undefined, f: (a:A) => void): void => a && f(a)
+
+const fold = <A, Z>(z: Z, a: A | undefined, f: (a:A) => Z): Z => a ? f(a) : z
 
 /**
  * A Render Prop component that mimics the react Component API
  */
 export class WithLifecycle<C> extends React.Component<
   WithLifecycleProps<C>,
-  {}
+  { context: C }
 > {
   constructor(props: WithLifecycleProps<C>) {
     super(props);
+    this.state = {
+      context: this.props.init()
+    }
+  }
+
+  static getDerivedStateFromProps<C>(nextProps: WithLifecycleProps<C>, state: { context: C }) {
+    return nextProps.deriveContext ? { context: nextProps.deriveContext(state.context) } : state
   }
 
   componentDidMount() {
-    this.context = this.props.componentDidMount();
+    iff(this.props.componentDidMount, dm => {
+      this.setState(s => {
+        context: dm(s.context)
+      })
+    })
   }
+
   componentWillUnmount() {
-    this.props.componentWillUnmount &&
-      this.props.componentWillUnmount(this.context);
+    iff(this.props.componentWillUnmount, wu => {
+      this.setState(s => {
+        context: wu(s.context)
+      })
+    })
   }
   shouldComponentUpdate() {
-    return this.props.shouldComponentUpdate
-      ? this.props.shouldComponentUpdate(this.context)
-      : true;
+    return fold(true, this.props.shouldComponentUpdate, scu => {
+      return scu(this.state.context)
+    })
+  }
+
+  UNSAFE_componentWillUpdate(nextProps: WithLifecycleProps<C>) {
+    iff(nextProps.componentWillUpdate, wu => {
+      this.setState(s => {
+        context: wu(s.context)
+      })
+    })
   }
 
   render() {
-    return this.props.children({});
+    return this.props.children(this.state.context);
   }
 }
 
@@ -52,6 +82,6 @@ export class WithLifecycle<C> extends React.Component<
  */
 export function withLifecycle<C>(
   options: WithLifecycleOptions<C>
-): ChainableComponent<{}> {
+): ChainableComponent<C> {
   return fromRenderProp<WithLifecycleProps<C>>(WithLifecycle, options);
 }