update(examples): Add Save & Restore example

* add localforage to dev deps

examples/SaveRestore/Controls.vue

@@ -0,0 +1,60 @@
+<script lang="ts" setup>
+import localforage from 'localforage'
+import { useZoomPanHelper, OnLoadParams, FlowExportObject, Node } from '~/index'
+
+localforage.config({
+  name: 'vue-flow',
+  storeName: 'flows',
+})
+
+const flowKey = 'example-flow'
+
+const getNodeId = () => `randomnode_${+new Date()}`
+
+const { transform } = useZoomPanHelper()
+
+type ControlsProps = {
+  flowInstance?: OnLoadParams
+}
+
+const props = defineProps<ControlsProps>()
+const emit = defineEmits(['restore', 'add'])
+
+const onSave = () => {
+  if (props.flowInstance) {
+    const flow = props.flowInstance.toObject()
+    localforage.setItem(flowKey, flow)
+  }
+}
+
+const onRestore = () => {
+  const restoreFlow = async () => {
+    const flow: FlowExportObject | null = await localforage.getItem(flowKey)
+
+    console.log(flow)
+    if (flow) {
+      const [x = 0, y = 0] = flow.position
+      emit('restore', flow.elements ?? [])
+      transform({ x, y, zoom: flow.zoom || 0 })
+    }
+  }
+
+  restoreFlow()
+}
+
+const onAdd = () => {
+  const newNode = {
+    id: `random_node-${getNodeId()}`,
+    data: { label: 'Added node' },
+    position: { x: Math.random() * window.innerWidth - 100, y: Math.random() * window.innerHeight },
+  } as Node
+  emit('add', newNode)
+}
+</script>
+<template>
+  <div class="save__controls">
+    <button @click="onSave">save</button>
+    <button @click="onRestore">restore</button>
+    <button @click="onAdd">add node</button>
+  </div>
+</template>

examples/SaveRestore/SaveRestoreExample.vue

@@ -0,0 +1,26 @@
+<script lang="ts" setup>
+import Controls from './Controls.vue'
+import Flow, { addEdge, Connection, Node, Edge, Elements, OnLoadParams, removeElements } from '~/index'
+
+import './save.css'
+
+const initialElements: Elements = [
+  { id: '1', data: { label: 'Node 1' }, position: { x: 100, y: 100 } },
+  { id: '2', data: { label: 'Node 2' }, position: { x: 100, y: 200 } },
+  { id: 'e1-2', source: '1', target: '2' },
+] as Elements
+
+const elements = ref(initialElements)
+const flowInstance = ref()
+
+const onConnect = (params: Connection | Edge) => (elements.value = addEdge(params, elements.value))
+const onElementsRemove = (elementsToRemove: Elements) => (elements.value = removeElements(elementsToRemove, elements.value))
+const onLoad = (instance: OnLoadParams) => (flowInstance.value = instance)
+const onRestore = (els: Elements) => (elements.value = els)
+const onAdd = (el: Node) => (elements.value = elements.value.concat(el))
+</script>
+<template>
+  <Flow :elements="elements" @elements-remove="onElementsRemove" @connect="onConnect" @load="onLoad">
+    <Controls :flow-instance="flowInstance" @restore="onRestore" @add="onAdd" />
+  </Flow>
+</template>

examples/SaveRestore/save.css

@@ -0,0 +1,11 @@
+.save__controls {
+  position: absolute;
+  right: 10px;
+  top: 10px;
+  z-index: 4;
+  font-size: 12px;
+}
+
+.save__controls button {
+  margin-left: 5px;
+}

examples/router.ts

@@ -65,6 +65,14 @@ export const routes: RouterOptions['routes'] = [
     path: '/overview',
     component: () => import('./Overview/Overview.vue'),
   },
+  {
+    path: '/provider',
+    component: () => import('./Provider/ProviderExample.vue'),
+  },
+  {
+    path: '/save-restore',
+    component: () => import('./SaveRestore/SaveRestoreExample.vue'),
+  },
 ]
 
 export const router = createRouter({