Refines how element styles are marshaled for custom elements

src/lib/custom-style.html

@@ -23,6 +23,9 @@
 browsers without non-native Shadow DOM.
 * Custom properties used by Polymer's shim for cross-scope styling
 may be defined in an `custom-style`.
+* An `include` attribute may be specified to pull in style data from a 
+`dom-module` matching the include attribute. By using `include`, style data
+can be shared between multiple `custom-style` elements.
 
 Example:
 
@@ -80,7 +83,17 @@
     is: 'custom-style',
     extends: 'style',
 
-    created: function() {
+    properties: {
+      // include is a property so that it deserializes
+      /**
+       * Specify `include` to identify a `dom-module` containing style data which
+       * should be used within the `custom-style`. By using `include` style data
+       * may be shared between multiple different `custom-style` elements.
+       */
+      include: String
+    },
+
+    ready: function() {
       // NOTE: we cannot just check attached because custom elements in 
       // HTMLImports do not get attached.
       this._tryApply();
@@ -101,7 +114,7 @@
           styleDefaults.addStyle(e);
           // we may not have any textContent yet due to parser yielding
           // if so, wait until we do...
-          if (e.textContent) {
+          if (e.textContent || this.include) {
             this._apply();
           } else {
             var observer = new MutationObserver(function() {
@@ -119,6 +132,9 @@
     _apply: function() {
       // used applied element from HTMLImports polyfill or this
       var e = this.__appliedElement || this;
+      if (this.include) {
+        e.textContent += styleUtil.cssFromModules(this.include);
+      }
       this._computeStyleProperties();
       var props = this._styleProperties;
       var self = this;

src/lib/dom-module.html

@@ -46,6 +46,9 @@
         this.getAttribute('name') || this.getAttribute('is');
       if (id) {
         this.id = id;
+        // store id separate from lowercased id so that
+        // in all cases mixedCase id will stored distinctly
+        // and lowercase version is a fallback
         modules[id] = this;
         lcModules[id.toLowerCase()] = this;
       }
@@ -87,20 +90,15 @@
   // loaded by this point. In addition the HTMLImports polyfill should be
   // changed to upgrade elements prior to running any scripts.)
   var cePolyfill = window.CustomElements && !CustomElements.useNative;
-  if (cePolyfill) {
-    var ready = CustomElements.ready;
-    CustomElements.ready = true;
-  }
   document.registerElement('dom-module', DomModule);
-  if (cePolyfill) {
-    CustomElements.ready = ready;
-  }
 
   function forceDocumentUpgrade() {
     if (cePolyfill) {
       var script = document._currentScript || document.currentScript;
-      if (script) {
-        CustomElements.upgradeAll(script.ownerDocument);
+      var doc = script && script.ownerDocument;
+      if (doc && !doc.__customElementsForceUpgraded) {
+        doc.__customElementsForceUpgraded = true;
+        CustomElements.upgradeAll(doc);
       }
     }
   }

src/lib/style-util.html

@@ -16,7 +16,8 @@
 
     return {
 
-      MODULE_STYLES_SELECTOR: 'style, link[rel=import][type~=css]',
+      MODULE_STYLES_SELECTOR: 'style, link[rel=import][type~=css], template',
+      INCLUDE_ATTR: 'include',
 
       toCssText: function(rules, callback, preserveProperties) {
         if (typeof rules === 'string') {
@@ -81,37 +82,69 @@
         return style;
       },
 
+      cssFromModules: function(moduleIds) {
+        var modules = moduleIds.trim().split(' ');
+        var cssText = '';
+        for (var i=0; i < modules.length; i++) {
+          cssText += this.cssFromModule(modules[i]);
+        }
+        return cssText;
+      },
+
       // returns cssText of styles in a given module; also un-applies any
       // styles that apply to the document.
       cssFromModule: function(moduleId) {
         var m = Polymer.DomModule.import(moduleId);
         if (m && !m._cssText) {
-          var cssText = '';
-          var e$ = Array.prototype.slice.call(
-            m.querySelectorAll(this.MODULE_STYLES_SELECTOR));
-          for (var i=0, e; i < e$.length; i++) {
-            e = e$[i];
+          m._cssText = this._cssFromElement(m);
+        }
+        return m && m._cssText || '';
+      },
+
+      // support lots of ways to discover css...
+      _cssFromElement: function(element) {
+        var cssText = '';
+        // if element is a template, get content from its .content
+        var content = element.content || element;
+        var sourceDoc = element.ownerDocument;
+        var e$ = Array.prototype.slice.call(
+          content.querySelectorAll(this.MODULE_STYLES_SELECTOR));
+        for (var i=0, e, resolveDoc, addModule; i < e$.length; i++) {
+          e = e$[i];
+          resolveDoc = sourceDoc;
+          addModule = null;
+          // look inside templates for elements
+          if (e.localName === 'template') {
+            cssText += this._cssFromElement(e);
+          } else {
             // style elements inside dom-modules will apply to the main document
             // we don't want this, so we remove them here.
             if (e.localName === 'style') {
+              addModule = e.getAttribute(this.INCLUDE_ATTR);
               // get style element applied to main doc via HTMLImports polyfill
               e = e.__appliedElement || e;
               e.parentNode.removeChild(e);
             // it's an import, assume this is a text file of css content.
             } else {
+              // TODO(sorvell): plan is to deprecate this way to get styles;
+              // remember to add deprecation warning when this is done.
               e = e.import && e.import.body;
+              resolveDoc = e.import;
             }
             // adjust paths in css.
             if (e) {
-              cssText += 
-                Polymer.ResolveUrl.resolveCss(e.textContent, e.ownerDocument);
+              cssText += this.resolveCss(e.textContent, resolveDoc);
             }
           }
-          m._cssText = cssText;
+          // now support module refs on 'styling' elements
+          if (addModule) {
+            cssText += this.cssFromModules(addModule);
+          }
         }
-        return m && m._cssText || '';
+        return cssText;
       },
-
+
+      resolveCss: Polymer.ResolveUrl.resolveCss,
       parser: Polymer.CssParse,
       ruleTypes: Polymer.CssParse.types
 

test/smoke/style-sharing/index.html

@@ -0,0 +1,35 @@
+<!doctype html>
+<html>
+<head>
+
+  <title></title>
+
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+
+  <script src="../../../../webcomponentsjs/webcomponents-lite.js"></script>
+  <link rel="import" href="../../../polymer.html">
+  <link rel="import" href="shared-styles.html">
+  <link rel="import" href="x-foo.html">
+</head>
+<body unresolved>
+
+  <style is="custom-style" module="shared-styles"></style>
+
+  <style is="custom-style">
+    .zot {
+      background-color: var(--zot);
+    }
+  </style>
+
+  <div class="bar">.bar from custom-style with module shared-styles</div>
+  <div class="foo">.foo should not be colored</div>
+  <div class="zot">.zot from custom-style using var in custom-style with module shared-styles</div>
+
+  <hr>
+
+  <x-foo></x-foo>
+
+
+</body>
+</html>

test/smoke/style-sharing/shared-styles.html

@@ -0,0 +1,11 @@
+<dom-module id="shared-styles">
+  <style type="polymer">
+    .bar {
+      background-color: steelblue;
+    }
+
+    :root {
+      --zot: seagreen;
+    }
+  </style>
+</dom-module>

test/smoke/style-sharing/x-foo.html

@@ -0,0 +1,31 @@
+<link rel="import" href="shared-styles.html">
+
+<dom-module id="x-foo">
+  <template>
+    <style module="shared-styles"></style>
+    <style>
+      .foo {
+        background-color: tomato;
+      }
+
+      :host {
+        display: block;
+        border: 1px dashed orange;
+        padding: 4px;
+      }
+
+      .zot {
+        background-color: var(--zot);
+      }
+    </style>
+    <h4>x-foo</h4>
+    <div class="bar">.bar from shared-styles.html</div>
+    <div class="foo">.foo from local stylesheet</div>
+    <div class="zot">.zot from var in shared-styles.html</div>
+  </template>
+  <script>
+    Polymer({
+
+    });
+  </script>
+</dom-module>

test/unit/custom-style-import.html

@@ -1,12 +1,23 @@
-<style is="custom-style">
-  :root {
+<dom-module id="shared-style">
+  <template>
+    <style>
+      :root {
+        --import-var: 3px solid orange;
+      }
+    </style>
+  </template>
+</dom-module>
+
+<link rel="import" href="sub/style-import.html">
 
-    --import-var: 3px solid orange;
+<style is="custom-style" include="shared-style style-import">
+  :root {
 
     --import-mixin: {
       border: 4px solid blue;
     };
 
     padding: 10px;
   }
-</style>
+</style>
+

test/unit/custom-style.html

@@ -119,6 +119,8 @@
   <br><br>
   <div id="after"></div>
 
+  <div class="foo"></div>
+
 
   <dom-module id="x-baz">
     <style>
@@ -253,6 +255,12 @@
         assertComputed(document.body, '12px');
       });
 
+      test('style paths in included dom-modules loaded in import', function() {
+        var foo = document.querySelector('.foo');
+        var url = getComputedStyle(foo).backgroundImage;
+        assert.include(url, 'sub/google.png');
+      });
+
     });
 
 

test/unit/styling-remote-elements.html

@@ -87,6 +87,8 @@
 
   </style>
   <template>
+    <!-- style in template using module! -->
+    <style include="remote-styles"></style>
     <content select=".blank"></content>
     <div id="simple">simple</div>
     <div id="complex1" class="scoped">complex1</div>
@@ -106,12 +108,12 @@
     <x-child2 class="wide" id="child2"></x-child2>
     <div id="computed" class$="{{computeClass(aClass)}}">Computed</div>
     <content></content>
+    <div id="url" class="foo"></div>
   </template>
 </dom-module>
 <script>
   Polymer({
     is: 'x-styled',
-    styleModules: ['remote-styles'],
 
     computeClass: function(className) {
       return className;

test/unit/styling-remote-module-sheet.html

@@ -1,4 +1,7 @@
+<link rel="import" href="sub/style-import.html">
 <dom-module id="remote-styles">
+<template>
+  <style include="style-import"></style>
   <style>
     #simple {
       border: 3px solid orange;
@@ -8,4 +11,5 @@
       border: 4px solid pink;
     }
   </style>
+</template>
 </dom-module>

test/unit/styling-remote.html

@@ -173,6 +173,12 @@
     assertComputed(order.$.me, '10px');
   });
 
+  test('style paths in included dom-modules loaded in import', function() {
+      var el = styled.$.url;
+      var url = getComputedStyle(el).backgroundImage;
+      assert.include(url, 'sub/google.png');
+    });
+
   // weird check allows testing under HTMLImports polyfill
   if (!window.Polymer || !Polymer.Settings.useNativeShadow) {
 

test/unit/styling-scoped-elements.html

@@ -1,10 +1,11 @@
 <dom-module id="x-gchild">
-  <style>
-    :host-context(.wide) #target {
-      border: 10px solid orange;
-    }
-  </style>
   <template>
+    <!-- styles can be in templates -->
+    <style>
+      :host-context(.wide) #target {
+        border: 10px solid orange;
+      }
+    </style>
     <div id="target">x-gchild</div>
   </template>
 </dom-module>

test/unit/sub/style-import.html

@@ -0,0 +1,11 @@
+<dom-module id="style-import">
+  <template>
+    <style>
+      .foo {
+        height: 2px;
+        border: 1px solid orange;
+        background: url(google.png);
+      }
+    </style>
+  </template>
+</dom-module>