Refactor client app data tags to be classnames and simplify logic

packages/client/src/components/Component.svelte

@@ -51,11 +51,11 @@
   $: children = instance._children || []
   $: id = instance._id
   $: name = instance._instanceName
-  $: empty =
-    !children.length &&
-    definition?.hasChildren &&
-    definition?.showEmptyState !== false &&
-    $builderStore.inBuilder
+  $: interactive =
+    $builderStore.inBuilder &&
+    ($builderStore.previewType === "layout" || insideScreenslot)
+  $: empty = interactive && !children.length && definition?.hasChildren
+  $: emptyState = empty && definition?.showEmptyState !== false
   $: rawProps = getRawProps(instance)
   $: instanceKey = JSON.stringify(rawProps)
   $: updateComponentProps(rawProps, instanceKey, $context)
@@ -63,9 +63,6 @@
     $builderStore.inBuilder &&
     $builderStore.selectedComponentId === instance._id
   $: inSelectedPath = $builderStore.selectedComponentPath?.includes(id)
-  $: interactive =
-    $builderStore.inBuilder &&
-    ($builderStore.previewType === "layout" || insideScreenslot)
   $: evaluateConditions(enrichedSettings?._conditions)
   $: componentSettings = { ...enrichedSettings, ...conditionalSettings }
 
@@ -73,8 +70,8 @@
   $: componentStore.set({
     id,
     children: children.length,
-    styles: { ...instance._styles, id, empty, interactive },
-    empty,
+    styles: { ...instance._styles, id, empty: emptyState, interactive },
+    empty: emptyState,
     selected,
     name,
   })
@@ -177,38 +174,44 @@
   // Drag and drop helper tags
   $: draggable = interactive && !isLayout && !isScreen
   $: droppable = interactive && !isLayout && !isScreen
-  $: dropInside = interactive && definition?.hasChildren && !children.length
 </script>
 
 {#key propsHash}
-  {#if constructor && componentSettings && (visible || inSelectedPath)}
-    <div
-      class={`component ${id}`}
-      data-type={interactive ? "component" : "readonly"}
-      data-id={id}
-      data-name={name}
-      data-draggable={draggable}
-      data-droppable={droppable}
-      data-droppable-inside={dropInside}
-    >
-      <svelte:component this={constructor} {...componentSettings}>
-        {#if children.length}
-          {#each children as child (child._id)}
-            <svelte:self instance={child} />
-          {/each}
-        {:else if empty}
-          <Placeholder />
-        {/if}
-      </svelte:component>
-    </div>
-  {/if}
+  {#key empty}
+    {#if constructor && componentSettings && (visible || inSelectedPath)}
+      <!-- The ID is used as a class because getElementsByClassName is O(1) -->
+      <!-- and the performance matters for the selection indicators -->
+      <div
+        class={`component ${id}`}
+        class:draggable
+        class:droppable
+        class:empty
+        class:interactive
+        data-id={id}
+        data-name={name}
+      >
+        <svelte:component this={constructor} {...componentSettings}>
+          {#if children.length}
+            {#each children as child (child._id)}
+              <svelte:self instance={child} />
+            {/each}
+          {:else if emptyState}
+            <Placeholder />
+          {/if}
+        </svelte:component>
+      </div>
+    {/if}
+  {/key}
 {/key}
 
 <style>
   .component {
     display: contents;
   }
-  [data-draggable="true"] :global(*:hover) {
+  .interactive :global(*:hover) {
+    cursor: pointer;
+  }
+  .draggable :global(*:hover) {
     cursor: grab;
   }
 </style>

packages/client/src/components/app/Container.svelte

@@ -34,7 +34,7 @@
     display: flex;
     max-width: 100%;
   }
-  .valid-container :global([data-type="component"] > *) {
+  .valid-container :global(.component > *) {
     max-width: 100%;
   }
   .direction-row {
@@ -46,7 +46,7 @@
 
   /* Grow containers inside a row need 0 width 0 so that they ignore content */
   /* The nested selector for data-type is the wrapper around all components */
-  .direction-row :global(> [data-type="component"] > .size-grow) {
+  .direction-row :global(> .component > .size-grow) {
     width: 0;
   }
 

packages/client/src/components/preview/DNDHandler.svelte

@@ -9,16 +9,15 @@
   let dropInfo
 
   const getDOMNodeForComponent = component => {
-    const parent = component.closest("[data-type='component']")
+    const parent = component.closest(".component")
     const children = Array.from(parent.childNodes)
     return children?.find(node => node?.nodeType === 1)
   }
 
   // Callback when initially starting a drag on a draggable component
   const onDragStart = e => {
-    const parent = e.target.closest("[data-type='component']")
-    const child = getDOMNodeForComponent(e.target)
-    if (!parent?.dataset?.id || !child) {
+    const parent = e.target.closest(".component")
+    if (!parent?.classList.contains("draggable")) {
       return
     }
 
@@ -31,7 +30,10 @@
     builderStore.actions.setDragging(true)
 
     // Highlight being dragged by setting opacity
-    child.style.opacity = "0.5"
+    const child = getDOMNodeForComponent(e.target)
+    if (child) {
+      child.style.opacity = "0.5"
+    }
   }
 
   // Callback when drag stops (whether dropped or not)
@@ -102,10 +104,10 @@
       return
     }
 
-    const element = e.target.closest("[data-type='component']")
+    const element = e.target.closest(".component")
     if (
       element &&
-      element.dataset.droppable === "true" &&
+      element.classList.contains("droppable") &&
       element.dataset.id !== dragInfo.target
     ) {
       // Do nothing if this is the same target
@@ -130,7 +132,7 @@
       dropInfo = {
         target,
         name: element.dataset.name,
-        droppableInside: element.dataset.droppableInside === "true",
+        droppableInside: element.classList.contains("empty"),
         bounds,
       }
     } else {

packages/client/src/components/preview/HoverIndicator.svelte

@@ -7,7 +7,7 @@
   $: zIndex = componentId === $builderStore.selectedComponentId ? 900 : 920
 
   const onMouseOver = e => {
-    const element = e.target.closest("[data-type='component']")
+    const element = e.target.closest(".interactive.component")
     const newId = element?.dataset?.id
     if (newId !== componentId) {
       componentId = newId

packages/client/src/utils/styleable.js

@@ -24,8 +24,8 @@ export const styleable = (node, styles = {}) => {
   let selectComponent
 
   // Allow dragging if required
-  const parent = node.closest("[data-type='component']")
-  if (parent && parent.dataset.draggable === "true") {
+  const parent = node.closest(".component")
+  if (parent && parent.classList.contains("draggable")) {
     node.setAttribute("draggable", true)
   }