From c7a81ea8a52e748a8ebd0ad321cd0b9ce9723d72 Mon Sep 17 00:00:00 2001
From: Kevin Schaaf <kschaaf@google.com>
Date: Fri, 12 May 2017 13:06:50 -0700
Subject: [PATCH] Move hostStack to property-effects and make readyClients
 explicit

---
 lib/mixins/element-mixin.html    | 50 ------------------
 lib/mixins/property-effects.html | 87 +++++++++++++++++++++++++++-----
 2 files changed, 73 insertions(+), 64 deletions(-)

diff --git a/lib/mixins/element-mixin.html b/lib/mixins/element-mixin.html
index 41d7551767..9f2733d234 100644
--- a/lib/mixins/element-mixin.html
+++ b/lib/mixins/element-mixin.html
@@ -576,7 +576,6 @@
        */
       _initializeProperties() {
         Polymer.telemetry.instanceCount++;
-        hostStack.registerHost(this);
         this.constructor.finalize();
         const importPath = this.constructor.importPath;
         // note: finalize template when we have access to `localName` to
@@ -649,9 +648,7 @@
        */
       ready() {
         if (this._template) {
-          hostStack.beginHosting(this);
           this.root = this._stampTemplate(this._template);
-          hostStack.endHosting(this);
           this.$ = this.root.$;
         }
         super.ready();
@@ -785,53 +782,6 @@
     return PolymerElement;
   });
 
-  /**
-   * Helper api for enqueing client dom created by a host element.
-   *
-   * By default elements are flushed via `_flushProperties` when
-   * `connectedCallback` is called. Elements attach their client dom to
-   * themselves at `ready` time which results from this first flush.
-   * This provides an ordering guarantee that the client dom an element
-   * creates is flushed before the element itself (i.e. client `ready`
-   * fires before host `ready`).
-   *
-   * However, if `_flushProperties` is called *before* an element is connected,
-   * as for example `Templatize` does, this ordering guarantee cannot be
-   * satisfied because no elements are connected. (Note: Bound elements that
-   * receive data do become enqueued clients and are properly ordered but
-   * unbound elements are not.)
-   *
-   * To maintain the desired "client before host" ordering guarantee for this
-   * case we rely on the "host stack. Client nodes registers themselves with
-   * the creating host element when created. This ensures that all client dom
-   * is readied in the proper order, maintaining the desired guarantee.
-   *
-   * @private
-   */
-  let hostStack = {
-
-    stack: [],
-
-    registerHost(inst) {
-      if (this.stack.length) {
-        let host = this.stack[this.stack.length-1];
-        host._enqueueClient(inst);
-      }
-    },
-
-    beginHosting(inst) {
-      this.stack.push(inst);
-    },
-
-    endHosting(inst) {
-      let stackLen = this.stack.length;
-      if (stackLen && this.stack[stackLen-1] == inst) {
-        this.stack.pop();
-      }
-    }
-
-  }
-
   /**
    * Provides basic tracking of element definitions (registrations) and
    * instance counts.
diff --git a/lib/mixins/property-effects.html b/lib/mixins/property-effects.html
index adfe6e26fc..917f29fa03 100644
--- a/lib/mixins/property-effects.html
+++ b/lib/mixins/property-effects.html
@@ -1086,6 +1086,7 @@
        */
       _initializeProperties() {
         super._initializeProperties();
+        hostStack.registerHost(this);
         this.__dataClientsInitialized = false;
         this.__dataPendingClients = null;
         this.__dataToNotify = null;
@@ -1431,22 +1432,40 @@
         if (!this.__dataClientsInitialized) {
           this.__dataClientsInitialized = true;
           this._readyClients();
+          this.__dataInitialized = true;
+        } else {
+          // Flush all clients
+          let clients = this.__dataPendingClients;
+          if (clients) {
+            this.__dataPendingClients = null;
+            for (let i=0; i < clients.length; i++) {
+              let client = clients[i];
+              if (client.__dataPending) {
+                client._flushProperties();
+              }
+            }
+          }
         }
-        // Flush all clients
+      }
+
+      /**
+       * Perform any initial setup on client dom. Called before the first
+       * `_flushProperties` call on client dom and before any element
+       * observers are called.
+       *
+       * @protected
+       */
+      _readyClients() {
         let clients = this.__dataPendingClients;
         if (clients) {
           this.__dataPendingClients = null;
           for (let i=0; i < clients.length; i++) {
             let client = clients[i];
-            // boot up client if necessary, otherwise flush properties
             if (!client.__dataPropertiesEnabled) {
               client._enableProperties();
-            } else if (client.__dataPending) {
-              client._flushProperties();
             }
           }
         }
-        this.__dataInitialized = true;
       }
 
       /**
@@ -1494,15 +1513,6 @@
         }
       }
 
-      /**
-       * Perform any initial setup on client dom. Called before the first
-       * `_flushProperties` call on client dom and before any element
-       * observers are called.
-       *
-       * @protected
-       */
-      _readyClients() {}
-
       /**
        * Implements `PropertyAccessors`'s properties changed callback.
        *
@@ -2205,7 +2215,9 @@
        * @protected
        */
       _stampTemplate(template) {
+        hostStack.beginHosting(this);
         let dom = super._stampTemplate(template);
+        hostStack.endHosting(this);
         let templateInfo = this._bindTemplate(template, true);
         // Add template-instance-specific data to instanced templateInfo
         templateInfo.nodeList = dom.nodeList;
@@ -2505,5 +2517,52 @@
     return PropertyEffects;
   });
 
+  /**
+   * Helper api for enqueing client dom created by a host element.
+   *
+   * By default elements are flushed via `_flushProperties` when
+   * `connectedCallback` is called. Elements attach their client dom to
+   * themselves at `ready` time which results from this first flush.
+   * This provides an ordering guarantee that the client dom an element
+   * creates is flushed before the element itself (i.e. client `ready`
+   * fires before host `ready`).
+   *
+   * However, if `_flushProperties` is called *before* an element is connected,
+   * as for example `Templatize` does, this ordering guarantee cannot be
+   * satisfied because no elements are connected. (Note: Bound elements that
+   * receive data do become enqueued clients and are properly ordered but
+   * unbound elements are not.)
+   *
+   * To maintain the desired "client before host" ordering guarantee for this
+   * case we rely on the "host stack. Client nodes registers themselves with
+   * the creating host element when created. This ensures that all client dom
+   * is readied in the proper order, maintaining the desired guarantee.
+   *
+   * @private
+   */
+  let hostStack = {
+
+    stack: [],
+
+    registerHost(inst) {
+      if (this.stack.length) {
+        let host = this.stack[this.stack.length-1];
+        host._enqueueClient(inst);
+      }
+    },
+
+    beginHosting(inst) {
+      this.stack.push(inst);
+    },
+
+    endHosting(inst) {
+      let stackLen = this.stack.length;
+      if (stackLen && this.stack[stackLen-1] == inst) {
+        this.stack.pop();
+      }
+    }
+
+  }
+
 })();
 </script>