From 19bdabfaaf322621e09b9aa923203c2affb26600 Mon Sep 17 00:00:00 2001
From: Michael Shanks <mike@budibase.com>
Date: Mon, 3 Aug 2020 15:06:51 +0100
Subject: [PATCH] binding  - backend initial

---
 .../builderStore/fetchBindableProperties.js   | 111 ++++++++++++++++
 packages/builder/tests/binding.spec.js        | 118 ++++++++++++++++++
 2 files changed, 229 insertions(+)
 create mode 100644 packages/builder/src/builderStore/fetchBindableProperties.js
 create mode 100644 packages/builder/tests/binding.spec.js

diff --git a/packages/builder/src/builderStore/fetchBindableProperties.js b/packages/builder/src/builderStore/fetchBindableProperties.js
new file mode 100644
index 0000000000..04648c4fb2
--- /dev/null
+++ b/packages/builder/src/builderStore/fetchBindableProperties.js
@@ -0,0 +1,111 @@
+export default function({ componentInstanceId, screen, components, models }) {
+  const { target, targetAncestors, bindableInstances, bindableContexts } = walk(
+    {
+      instance: screen.props,
+      targetId: componentInstanceId,
+      components,
+      models,
+    }
+  )
+
+  return [
+    ...bindableInstances
+      .filter(isComponentInstanceAvailable)
+      .map(componentInstanceToBindable),
+    ...bindableContexts.map(contextToBindables),
+  ]
+}
+
+const isComponentInstanceAvailable = i => true
+
+// turns a component instance prop into binding expressions
+// used by the UI
+const componentInstanceToBindable = i => ({
+  type: "instance",
+  instance: i.instance,
+  // how the binding expression persists, and is used in the app at runtime
+  runtimeBinding: `state.${i.instance._id}.${i.prop}`,
+  // how the binding exressions looks to the user of the builder
+  readableBinding: `${i.instance._instanceName}`,
+})
+
+const contextToBindables = c => {
+  const contextParentNumber = 0
+  const contextParentPath = Array[contextParentNumber]
+    .map(() => "_parent")
+    .join(".")
+  return Object.keys(c.schema).map(k => ({
+    type: "context",
+    instance: c.instance,
+    // how the binding expression persists, and is used in the app at runtime
+    runtimeBinding: `context.${contextParentPath}.${k}`,
+    // how the binding exressions looks to the user of the builder
+    readableBinding: `${c.instance._instanceName}.${c.schema.name}.${k}`,
+  }))
+}
+
+const walk = ({ instance, targetId, components, models, result }) => {
+  if (!result) {
+    result = {
+      currentAncestors: [],
+      currentContexts: [],
+      target: null,
+      targetAncestors: [],
+      bindableInstances: [],
+      bindableContexts: [],
+      parentMap: {},
+    }
+  }
+
+  // "component" is the component definition (object in component.json)
+  const component = components[instance._component]
+  const parentInstance =
+    result.currentAncestors.length > 0 &&
+    result.currentAncestors[result.currentAncestors.length - 1]
+
+  if (instance._id === targetId) {
+    // set currentParents to be result parents
+    result.targetAncestors = result.currentAncestors
+    result.bindableContexts = result.currentContexts
+    // found it
+    result.target = instance
+  } else {
+    if (instance.bindable) {
+      // pushing all components in here initially
+      // but this will not be correct, as some of
+      // these components will be in another context
+      // but we dont know this until the end of the walk
+      // so we will filter in another metod
+      result.bindableInstances.push({
+        instance,
+        prop: instance.bindable,
+      })
+    }
+  }
+  console.log(instance._component)
+  console.debug(components)
+  // a component that provides context to it's children
+  const contextualInstance = component.context && instance[component.context]
+
+  if (contextualInstance) {
+    // add to currentContexts (ancestory of context)
+    // before walking children
+    const schema = models.find(m => m._id === instance[component.context])
+      .schema
+    result.currentContexts.push({ instance, schema })
+  }
+
+  for (let child of instance._children || []) {
+    result.parentMap[child._id] = parentInstance._id
+    result.currentAncestors.push(instance)
+    walk({ instance, targetId, components, models, result })
+    result.currentAncestors.pop()
+  }
+
+  if (contextualInstance) {
+    // child walk done, remove from currentContexts
+    result.currentContexts.pop()
+  }
+
+  return result
+}
diff --git a/packages/builder/tests/binding.spec.js b/packages/builder/tests/binding.spec.js
new file mode 100644
index 0000000000..0666edb39e
--- /dev/null
+++ b/packages/builder/tests/binding.spec.js
@@ -0,0 +1,118 @@
+import fetchbindableProperties from "../src/builderStore/fetchBindableProperties"
+
+describe("fetch bindable properties", () => {
+
+  it("should return bindable properties from screen components", () => {
+    const result = fetchbindableProperties({
+      componentInstanceId: "heading-id",
+      ...testData()
+    })
+    const componentBinding = result.find(r => r.instance._id === "search-input-id")
+    expect(componentBinding).toBeDefined()
+    expect(componentBinding.type).toBe("instance")
+    expect(componentBinding.runtimeBinding).toBe("state.search-input-id.value")
+  })
+
+  it("should not return bindable components when not in their context", () => {
+
+  })
+
+  it("should return model schema, when inside a context", () => {
+
+  })
+
+  it("should return model schema, for grantparent context", () => {
+
+  })
+
+  it("should return bindable component props, from components in same context", () => {
+
+  })
+
+  it("should not return model props from child context", () => {
+
+  })
+
+  
+
+})
+
+const testData = () => {
+
+  const screen = {
+    instanceName: "test screen",
+    name: "screen-id",
+    route: "/",
+    props: {
+      _id:"screent-root-id", 
+      _component: "@budibase/standard-components/container",
+      _children: [
+        {
+          _id: "heading-id",
+          _instanceName: "list item heading",
+          _component: "@budibase/standard-components/heading",
+          text: "Screen Title"
+        },
+        {
+          _id: "search-input-id",
+          _instanceName: "Search Input",
+          _component: "@budibase/standard-components/input",
+          value: "search phrase"
+        },
+        {
+          _id: "list-id",
+          _component: "@budibase/standard-components/list",
+          _instanceName: "list-name",
+          model: "test-model-id",
+          _children: [
+            {
+              _id: "list-item-heading-id",
+              _instanceName: "list item heading",
+              _component: "@budibase/standard-components/heading",
+              text: "hello"
+            }
+          ]
+        },
+      ]
+    }
+  }
+
+  const models = [{
+    id: "test-model-id",
+    name: "Test Model",
+      schema: {
+        name: {
+          type: "string"
+        },
+        description: {
+          type: "string"
+        }
+    }
+  }]
+
+  const components = {
+    "@budibase/standard-components/container" : {
+      props: {},
+    },
+    "@budibase/standard-components/list" : {
+      context: "model",
+      props: {
+        model: "string"
+      },
+    },
+    "@budibase/standard-components/input" : {
+      bindable: "value",
+      props: {
+        value: "string"
+      },
+    },
+    "@budibase/standard-components/heading" : {
+      props: {
+        text: "string"
+      },
+    },
+  }
+
+  return { screen, models, components }
+
+}
\ No newline at end of file