From 5f6b846937161accd2100b5bdef2881359d8e5b6 Mon Sep 17 00:00:00 2001
From: Andrew Kingston <andrew@kingston.dev>
Date: Fri, 16 Feb 2024 13:25:41 +0000
Subject: [PATCH] Add ability for components to provide example data context
 that they provide so that more bindings work with live eval

---
 .../common/bindings/BindingPicker.svelte      |  2 -
 .../client/src/components/Component.svelte    | 11 ++++-
 .../src/components/app/GridBlock.svelte       | 14 ++++++
 packages/client/src/sdk.js                    |  2 +
 packages/client/src/utils/components.js       | 49 +++++++++++++++++++
 5 files changed, 75 insertions(+), 3 deletions(-)

diff --git a/packages/builder/src/components/common/bindings/BindingPicker.svelte b/packages/builder/src/components/common/bindings/BindingPicker.svelte
index cb990b277a..5ff304fdb2 100644
--- a/packages/builder/src/components/common/bindings/BindingPicker.svelte
+++ b/packages/builder/src/components/common/bindings/BindingPicker.svelte
@@ -69,8 +69,6 @@
     return names
   }
 
-  $: console.log(context)
-
   const getBindingValue = binding => {
     const hbs = `{{ ${binding.runtimeBinding} }}`
     return processStringSync(hbs, context)
diff --git a/packages/client/src/components/Component.svelte b/packages/client/src/components/Component.svelte
index 6d6af91dcc..e7024ac17f 100644
--- a/packages/client/src/components/Component.svelte
+++ b/packages/client/src/components/Component.svelte
@@ -575,6 +575,15 @@
     }
   }
 
+  const getDataContext = () => {
+    const normalContext = get(context)
+    const additionalContext = ref?.getAdditionalDataContext?.()
+    return {
+      ...normalContext,
+      ...additionalContext,
+    }
+  }
+
   onMount(() => {
     // Register this component instance for external access
     if ($appStore.isDevApp) {
@@ -583,7 +592,7 @@
           component: instance._component,
           getSettings: () => cachedSettings,
           getRawSettings: () => ({ ...staticSettings, ...dynamicSettings }),
-          getDataContext: () => get(context),
+          getDataContext: getDataContext,
           reload: () => initialise(instance, true),
           setEphemeralStyles: styles => (ephemeralStyles = styles),
           state: store,
diff --git a/packages/client/src/components/app/GridBlock.svelte b/packages/client/src/components/app/GridBlock.svelte
index 0a343cac51..c2bc9f3989 100644
--- a/packages/client/src/components/app/GridBlock.svelte
+++ b/packages/client/src/components/app/GridBlock.svelte
@@ -30,6 +30,7 @@
     ActionTypes,
     createContextStore,
     Provider,
+    generateGoldenSample,
   } = getContext("sdk")
 
   let grid
@@ -48,6 +49,19 @@
     },
   ]
 
+  // Provide additional data context for live binding eval
+  export const getAdditionalDataContext = () => {
+    const rows = get(grid?.getContext()?.rows)
+    const goldenRow = generateGoldenSample(rows)
+    const id = [get(component).id]
+    return {
+      [id]: goldenRow,
+      eventContext: {
+        row: goldenRow,
+      },
+    }
+  }
+
   // Parses columns to fix older formats
   const getParsedColumns = columns => {
     // If the first element has an active key all elements should be in the new format
diff --git a/packages/client/src/sdk.js b/packages/client/src/sdk.js
index 557d5ca8da..c0b99cd131 100644
--- a/packages/client/src/sdk.js
+++ b/packages/client/src/sdk.js
@@ -28,6 +28,7 @@ import { ActionTypes } from "./constants"
 import { fetchDatasourceSchema } from "./utils/schema.js"
 import { getAPIKey } from "./utils/api.js"
 import { enrichButtonActions } from "./utils/buttonActions.js"
+import { generateGoldenSample } from "./utils/components.js"
 import { processStringSync, makePropSafe } from "@budibase/string-templates"
 import { fetchData, LuceneUtils, Constants } from "@budibase/frontend-core"
 
@@ -65,6 +66,7 @@ export default {
   processStringSync,
   makePropSafe,
   createContextStore,
+  generateGoldenSample,
 
   // Components
   Provider,
diff --git a/packages/client/src/utils/components.js b/packages/client/src/utils/components.js
index 1812175c2c..70f80e4329 100644
--- a/packages/client/src/utils/components.js
+++ b/packages/client/src/utils/components.js
@@ -82,3 +82,52 @@ export const findComponentParent = (rootComponent, id, parentComponent) => {
   }
   return null
 }
+
+/**
+ * Util to check is a given value is "better" than another. "Betterness" is
+ * defined as presence and length.
+ */
+const isBetterSample = (newValue, oldValue) => {
+  // Prefer non-null values
+  if (oldValue == null && newValue != null) {
+    return true
+  }
+
+  // Don't change type
+  const oldType = typeof oldValue
+  const newType = typeof newValue
+  if (oldType !== newType) {
+    return false
+  }
+
+  // Prefer longer values
+  if (newType === "string" && newValue.length > oldValue.length) {
+    return true
+  }
+  if (
+    newType === "object" &&
+    Object.keys(newValue).length > Object.keys(oldValue).length
+  ) {
+    return true
+  }
+
+  return false
+}
+
+/**
+ * Generates a best-case example object of the provided samples.
+ * The generated sample does not necessarily exist - it simply is a sample that
+ * contains "good" examples for every property of all the samples.
+ * The generate sample will have a value for all keys across all samples.
+ */
+export const generateGoldenSample = samples => {
+  let goldenSample = {}
+  samples?.forEach(sample => {
+    Object.keys(sample).forEach(key => {
+      if (isBetterSample(sample[key], goldenSample[key])) {
+        goldenSample[key] = sample[key]
+      }
+    })
+  })
+  return goldenSample
+}