Fixes #452 - Deprecate the layout taglib

compiler/ast/CustomTag.js

@@ -5,6 +5,7 @@ var removeDashes = require('../util/removeDashes');
 var safeVarName = require('../util/safeVarName');
 var ok = require('assert').ok;
 var tagLoader;
+var Node = require('./Node');
 
 var CUSTOM_TAG_KEY = Symbol('CustomTag');
 
@@ -156,6 +157,51 @@ function processDirectlyNestedTags(node, codegen) {
     });
 }
 
+function merge(props1, props2, context) {
+    if (!props2) {
+        return props1;
+    }
+
+    if (!(props2 instanceof Node)) {
+        if (Object.keys(props2).length === 0) {
+            return props1;
+        }
+    }
+
+    if (props1 instanceof Node) {
+        let mergeVar = context.helper('merge');
+        if (!(props2 instanceof Node)) {
+            props2 = context.builder.literal(props2);
+        }
+
+        return context.builder.functionCall(mergeVar, [
+            props2, // Input props from the attributes take precedence
+            props1
+        ]);
+    } else {
+        if (props2 instanceof Node) {
+            let mergeVar = context.helper('merge');
+
+            return context.builder.functionCall(mergeVar, [
+                props2, // Input props from the attributes take precedence
+                props1
+
+            ]);
+        } else {
+            if (props1._arg) {
+                let mergeVar = context.helper('merge');
+                props1._arg = context.builder.functionCall(mergeVar, [
+                    context.builder.literal(props2), // Input props from the attributes take precedence
+                    props1._arg
+                ]);
+                return props1;
+            } else {
+                return Object.assign(props1, props2);
+            }
+        }
+    }
+}
+
 class CustomTag extends HtmlElement {
     constructor(el, tagDef) {
         super(el);
@@ -168,6 +214,8 @@ class CustomTag extends HtmlElement {
         this._condition = null;
         this._foundNestedTagsByName = {};
         this._hasDynamicNestedTags = false;
+        this._additionalProps = null;
+        this._rendererPath = null;
     }
 
     buildInputProps(codegen) {
@@ -342,6 +390,26 @@ class CustomTag extends HtmlElement {
         byNameArray.push(nestedTag);
     }
 
+    addProps(additionalProps) {
+        if (!this._additionalProps) {
+            this._additionalProps = {};
+        }
+
+        Object.assign(this._additionalProps, additionalProps);
+    }
+
+    addProp(name, value) {
+        if (!this._additionalProps) {
+            this._additionalProps = {};
+        }
+        this._additionalProps[name] = value;
+    }
+
+    setRendererPath(path) {
+        ok(typeof path === 'string', '"path" should be a string');
+        this._rendererPath = path;
+    }
+
     getNestedTagVar(context) {
         if (!this._nestedTagVar) {
             var tagDef = this.tagDef;
@@ -364,25 +432,22 @@ class CustomTag extends HtmlElement {
 
         var tagDef = this.resolveTagDef(codegen);
 
+        if (!tagDef) {
+            // The tag def was not able to be resolved and an error should have already
+            // been added to the context
+            return null;
+        }
+
         var parentCustomTag;
 
-        // console.log('BEGIN:', JSON.stringify(this, null, 2));
-
-        // console.log(module.id, 'generateCode BEGIN:', this.tagName, new Error().stack);
-
         context.pushData(CUSTOM_TAG_KEY, this);
         processDirectlyNestedTags(this, codegen);
         var body = codegen.generateCode(this.body);
         context.popData(CUSTOM_TAG_KEY);
 
-        // console.log(module.id, 'generateCode   END:', this.tagName);
-
         var isNestedTag = tagDef.isNestedTag === true;
         if (isNestedTag) {
             parentCustomTag = context.getData(CUSTOM_TAG_KEY);
-
-            // console.log('parentCustomTag:', parentCustomTag.tagName, 'child:', tagDef.name);
-
             if (!parentCustomTag) {
                 if (tagDef.parentTagName) {
                     codegen.addError(`Invalid usage of the <${this.tagName}> nested tag. Tag not nested within a <${tagDef.parentTagName}> tag.`);
@@ -435,12 +500,6 @@ class CustomTag extends HtmlElement {
 
         var inputProps = this.buildInputProps(codegen);
 
-        // if (isNestedTag) {
-        //     isRepeated = tagDef.isRepeated === true;
-        //     targetProperty = tagDef.targetProperty;
-        //     parentTagVar = parentCustomTag.getNestedTagVar(context);
-        // }
-
         var renderBodyFunction;
 
         if (body && body.length) {
@@ -481,29 +540,31 @@ class CustomTag extends HtmlElement {
             bodyOnlyIf = null;
         }
 
-        inputProps = builder.literal(inputProps);
+        var argExpression;
 
-        var argument = this.argument;
+        if (this.argument) {
+            argExpression = builder.parseExpression(this.argument);
+        }
 
-        if (argument) {
+        var additionalProps = this._additionalProps;
-            argument = builder.parseExpression(argument);
 
-            if (Object.keys(inputProps.value).length === 0) {
+        if (additionalProps) {
-                inputProps = argument;
+            inputProps = merge(additionalProps, inputProps, context);
-            } else {
+        }
-                var mergeVar = context.helper('merge');
+
-                inputProps = builder.functionCall(mergeVar, [
+        if (argExpression) {
-                    inputProps, // Input props from the attributes take precedence
+            inputProps = merge(argExpression, inputProps, context);
-                    argument
+        }
-                ]);
+
-            }
+        if (!(inputProps instanceof Node)) {
+            inputProps = builder.literal(inputProps);
         }
 
         if (hasDynamicNestedTags) {
             inputProps = builder.functionCall(context.helper('mergeNestedTagsHelper'), [ inputProps ]);
         }
 
-        var rendererPath = tagDef.renderer;
+        var rendererPath = this._rendererPath || tagDef.renderer;
         var rendererRequirePath;
         var requireRendererFunctionCall;
 

package.json

@@ -30,7 +30,7 @@
     "test-express": "mocha --ui bdd --reporter spec ./test/express-test",
     "test-widgets": "npm run test-widgets-browser -s && npm run test-widgets-browser-deprecated -s && npm run jshint --silent",
     "test-widgets-browser": "node test/browser-tests-runner/cli.js test/widgets-browser-tests.js --automated && npm run test-widgets-browser-pages",
-    "test-widgets-browser-deprecated": "node test/browser-tests-runner/cli.js test/widgets-browser-deprecated-tests.js --automated && npm run test-widgets-browser-pages",
+    "test-widgets-browser-deprecated": "node test/browser-tests-runner/cli.js test/deprecated-widgets-browser-tests.js --automated && npm run test-widgets-browser-pages",
     "test-widgets-browser-pages": "node test/browser-tests-runner/cli.js --pages --automated",
     "test-widgets-browser-dev": "browser-refresh test/browser-tests-runner/cli.js test/widgets-browser-tests.js --server",
     "test-widgets-page": "browser-refresh test/browser-tests-runner/cli.js test/widgets-browser-tests.js --server --page",

runtime/helpers.js

@@ -251,4 +251,3 @@ exports.cl = function classListHelper() {
  * Loads a template (__helpers.l --> marko_loadTemplate(path))
  */
 exports.l = require('./loader');
-exports.i = require('./include');

runtime/include.js

@@ -1,17 +0,0 @@
-module.exports = function include(target, out, data) {
-    if (target) {
-        if (typeof target === 'function') {
-            target(out, data);
-        } else if (typeof target === 'object') {
-            if (target.renderBody) {
-                target.renderBody(out, data);
-            } else if (target.renderer) {
-                target.renderer(data, out);
-            } else if (target.render) {
-                target.render(data, out);
-            }
-        } else {
-            throw new Error('Invalid include target: ' + target);
-        }
-    }
-};

taglibs/core/include-tag-transformer.js

@@ -0,0 +1,34 @@
+'use strict';
+
+module.exports = function codeGenerator(el, context) {
+    let builder = context.builder;
+
+    let target;
+    let arg;
+
+    if (el.argument) {
+        let args = el.argument && builder.parseJavaScriptArgs(el.argument);
+        el.argument = null;
+
+        target = args[0];
+        arg = args[1];
+    } else {
+        return;
+    }
+
+    if (target.type === 'Literal') {
+        target = context.importTemplate(target.value);
+    }
+
+    var includeProps = {
+        _target: target
+    };
+
+    if (arg) {
+        includeProps._arg = arg;
+    }
+
+    el.data.includeTarget = target;
+
+    el.addProps(includeProps);
+};

taglibs/core/include-tag.js

@@ -1,87 +1,20 @@
-'use strict';
+module.exports = function include(input, out) {
-var removeHyphens = require('../../compiler/util/removeDashes');
+    var target = input._target;
-
+    var arg = input._arg || input;
-module.exports = function codeGenerator(el, codegen) {
-    let builder = codegen.builder;
-
-    let target;
-    let data;
-
-    if (el.argument) {
-        let args = el.argument && builder.parseJavaScriptArgs(el.argument);
-        target = args[0];
-        data = args[1];
-    }
-
-    var isTemplate = false;
 
     if (target) {
-        if (target.type === 'Literal') {
+        if (typeof target === 'function') {
-            target = codegen.context.importTemplate(target.value);
+            target(out, arg);
-            isTemplate = true;
+        } else if (typeof target === 'object') {
-        }
+            if (target.renderBody) {
-    }
+                target.renderBody(out, arg);
-
+            } else if (target.renderer) {
-    let finalData = {};
+                target.renderer(arg, out);
-    let attrs = el.getAttributes();
+            } else if (target.render) {
-    attrs.forEach((attr) => {
+                target.render(arg, out);
-        var propName = attr.name;
-        if (propName.indexOf('-') !== -1) {
-            propName = removeHyphens(propName); // Convert the property name to camel case
-        }
-
-        finalData[propName] = attr.value;
-    });
-
-    if (el.body && el.body.length) {
-        finalData.renderBody = builder.renderBodyFunction(el.body);
-    }
-
-    if (data) {
-        if (Object.keys(finalData).length === 0) {
-            finalData = data;
-        } else {
-            let mergeVar = codegen.context.helper('merge');
-            finalData = builder.functionCall(mergeVar, [
-                builder.literal(finalData), // Input props from the attributes take precedence
-                data // The template data object is passed as the second argument: <include("./foo.marko", { ... })/>
-            ]);
-        }
-    } else {
-        if (Object.keys(finalData).length === 0) {
-            finalData = null;
-        } else {
-            finalData = builder.literal(finalData);
-        }
-    }
-
-    if (isTemplate) {
-        let renderMethod = builder.memberExpression(target, builder.identifier('render'));
-        if (!finalData) {
-            finalData = builder.literal({});
-        }
-        let renderArgs = [ finalData, builder.identifierOut()  ];
-        let renderFunctionCall = builder.functionCall(renderMethod, renderArgs);
-        return renderFunctionCall;
-    } else {
-        if (this.generateCodeForDynamicInclude) {
-            return this.generateCodeForDynamicInclude({
-                target: target,
-                data: finalData
-            }, codegen);
-        } else {
-            if (!target) {
-                target = builder.memberExpression(builder.identifier('data'), builder.identifier('renderBody'));
             }
-
+        } else {
-            let includeVar = codegen.context.helper('include');
+            throw new Error('Invalid include target: ' + target);
-            let includeArgs = [ target, builder.identifierOut() ];
-
-            if (finalData) {
-                includeArgs.push(finalData);
-            }
-
-            return builder.functionCall(includeVar, includeArgs);
         }
     }
 };

taglibs/core/marko.json

@@ -79,7 +79,8 @@
         "code-generator": "./import-tag"
     },
     "<include>": {
-        "code-generator": "./include-tag",
+        "renderer": "./include-tag",
+        "transformer": "./include-tag-transformer",
         "autocomplete": [
             {
                 "displayText": "include(<template>)",

taglibs/layout/use-tag-transformer.js

@@ -6,6 +6,9 @@ module.exports = function transform(el, context) {
         context.addError(el, 'Invalid <layout-use> tag. Expected: <layout-use(template[, data]) ...>');
         return;
     }
+
+    console.warn('The <layout-use> tag is deprecated. Please use <include> instead. See: https://github.com/marko-js/marko/issues/452 (' + (el.pos ? context.getPosInfo(el.pos) : context.filename) + ')');
+
     var builder = context.builder;
 
     var args = builder.parseJavaScriptArgs(argument);

test/autotests/render/include-layout-data-attrs/expected.html

@@ -0,0 +1 @@
+<div>BODY CONTENT</div> ---- <h1>DEFAULT TITLE</h1><div>BODY CONTENT</div><h1>FOOTER CONTENT</h1>

test/autotests/render/include-layout-data-attrs/layout-default.marko

@@ -0,0 +1,19 @@
+<h1 if(data.showHeader !== false)>
+    <if(data.header)>
+        <include(data.header)/>
+    </if>
+    <else>
+        DEFAULT TITLE
+    </else>
+</h1>
+<div>
+    <include(data.body)/>
+</div>
+<h1 if(data.showFooter !== false)>
+    <if(data.footer)>
+        <include(data.footer)/>
+    </if>
+    <else>
+        DEFAULT FOOTER
+    </else>
+</h1>

test/autotests/render/include-layout-data-attrs/template.marko

@@ -0,0 +1,11 @@
+-------
+<include("./layout-default.marko", {showHeader: false}) show-footer=false>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>
+----
+<include("./layout-default.marko", {showHeader: false}) show-header=true>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>
+-------

test/autotests/render/include-layout-data-attrs/test.js

@@ -0,0 +1,3 @@
+exports.templateData = {
+    layoutDynamic: require('./layout-default.marko')
+};

test/autotests/render/include-layout-data/expected.html

@@ -0,0 +1 @@
+<div>BODY CONTENT</div>FOOTER CONTENT ---- <h1>DEFAULT TITLE</h1><div>BODY CONTENT2</div>FOOTER CONTENT2 ---- <h1>My Title</h1><div>BODY CONTENT2</div>FOOTER CONTENT2

test/autotests/render/include-layout-data/layout-default.marko

@@ -0,0 +1,13 @@
+<h1 if(data.showHeader !== false)>
+    <if(data.header)>
+        <include(data.header)/>
+    </if>
+    <else>
+        DEFAULT TITLE
+    </else>
+</h1>
+<div>
+    <include(data.body)/>
+</div>
+<include(data.footer)/>
+<include(data.empty)/>

test/autotests/render/include-layout-data/template.marko

@@ -0,0 +1,17 @@
+---------
+<include("./layout-default.marko", {showHeader: false})>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>
+----
+<include("./layout-default.marko", {showHeader: true})>
+    <@body>BODY CONTENT2</@body>
+    <@footer>FOOTER CONTENT2</@footer>
+</include>
+----
+<include("./layout-default.marko", {showHeader: true})>
+    <@header>My Title</@header>
+    <@body>BODY CONTENT2</@body>
+    <@footer>FOOTER CONTENT2</@footer>
+</include>
+---------

test/autotests/render/include-layout-data/test.js

@@ -0,0 +1,3 @@
+exports.templateData = {
+    layoutDynamic: require('./layout-default.marko')
+};

test/autotests/render/include-layout/expected.html

@@ -0,0 +1 @@
+<div>BODY CONTENT</div>FOOTER CONTENT<h1>HEADER CONTENT</h1><div>BODY CONTENT</div>FOOTER CONTENT<h1>VALUE HEADER</h1><div>BODY CONTENT</div>FOOTER CONTENT<h1>DEFAULT TITLE</h1><div>BODY CONTENT</div>FOOTER CONTENT

test/autotests/render/include-layout/layout-default.marko

@@ -0,0 +1,13 @@
+<h1 if(data.showHeader !== false)>
+    <if(data.header)>
+        <include(data.header)/>
+    </if>
+    <else>
+        DEFAULT TITLE
+    </else>
+</h1>
+<div>
+    <include(data.body)/>
+</div>
+<include(data.footer)/>
+<include(data.empty)/>

test/autotests/render/include-layout/template.marko

@@ -0,0 +1,18 @@
+<include("./layout-default.marko") show-header=false>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>
+<include("./layout-default.marko") show-header=true>
+    <@header>HEADER CONTENT</@header>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>
+<include("./layout-default.marko") show-header=true>
+    <@header>VALUE HEADER</@header>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>
+<include(data.layoutDynamic) show-header=true>
+    <@body>BODY CONTENT</@body>
+    <@footer>FOOTER CONTENT</@footer>
+</include>

test/autotests/render/include-layout/test.js

@@ -0,0 +1,3 @@
+exports.templateData = {
+    layoutDynamic: require('./layout-default.marko')
+};

test/autotests/render/include-renderBody-data-and-attrs/expected.html

@@ -0,0 +1 @@
+<div>Frank:10</div>

test/autotests/render/include-renderBody-data-and-attrs/template.marko

@@ -0,0 +1 @@
+<include(data.renderBody, {name: 'Frank'}) age=10/>

test/autotests/render/include-renderBody-data-and-attrs/test.js

@@ -0,0 +1,7 @@
+exports.templateData = {
+    renderBody(out, data) {
+        out.beginElement('div');
+        out.text(data.name + ':' + data.age);
+        out.endElement();
+    }
+};

test/autotests/render/include-renderBody/include-html-target.html

@@ -1,5 +0,0 @@
-<div>
-    <h1>
-        Hello World!
-    </h1>
-</div>

test/deprecated-render-test.js

@@ -0,0 +1,22 @@
+'use strict';
+require('./util/patch-module');
+
+var chai = require('chai');
+chai.config.includeStack = true;
+var path = require('path');
+var autotest = require('./autotest');
+var runRenderTest = require('./util/runRenderTest');
+
+require('../node-require').install();
+
+describe('render', function() {
+    var autoTestDir = path.join(__dirname, 'autotests/render-deprecated');
+
+    autotest.scanDir(
+        autoTestDir,
+        function run(dir, helpers, done) {
+            runRenderTest(dir, helpers, done, {
+                output: 'html'
+            });
+        });
+});

widgets/taglib/TransformHelper/getContainingWidgetNode.js

@@ -1,18 +1,3 @@
-/*
- * Copyright 2011 eBay Software Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
 
 function getContainingWidgetNode() {
     if (this.containingWidgetNode !== undefined) {
@@ -22,7 +7,7 @@ function getContainingWidgetNode() {
     var curNode = this.el;
 
     while (true) {
-        if (curNode.tagName === 'w-widget') {
+        if (curNode.tagName === '_widget') {
             this.containingWidgetNode = curNode;
             return this.containingWidgetNode;
         } else if (curNode.isFlagSet('hasWidgetExtend')) {

widgets/taglib/TransformHelper/handleIncludeNode.js

@@ -1,5 +1,7 @@
 'use strict';
 
+var includeTagForWidgets = require.resolve('../include-tag');
+
 module.exports = function(includeNode) {
     var builder = this.builder;
     var context = this.context;
@@ -11,15 +13,13 @@ module.exports = function(includeNode) {
 
     var parentNode = includeNode.parentNode;
 
-    var parentTransformHelper;
-
     parentNode._normalizeChildTextNodes(context);
 
     if (parentNode.childCount === 1) {
-        parentTransformHelper = this.getTransformHelper(parentNode);
+        let parentTransformHelper = this.getTransformHelper(parentNode);
 
         if (includeNode.argument) {
-            var widgetIdInfo = parentTransformHelper.assignWidgetId(true /* repeated */);
+            let widgetIdInfo = parentTransformHelper.assignWidgetId(true /* repeated */);
             if (!widgetIdInfo.idVarNode) {
                 let idVarNode = widgetIdInfo.createIdVarNode();
                 parentNode.onBeforeGenerateCode((event) => {
@@ -30,35 +30,44 @@ module.exports = function(includeNode) {
             parentTransformHelper.assignWidgetId(false /* not repeated */);
             widgetTagNode.setAttributeValue('body', parentTransformHelper.getNestedIdExpression());
         }
+
+        if (!includeNode.data.includeTarget) {
+            includeNode.addProp('_target', builder.memberExpression(builder.identifier('data'), builder.identifier('widgetBody')));
+        }
+
+        includeNode.setRendererPath(includeTagForWidgets);
+
+        includeNode.onBeforeGenerateCode(function() {
+            includeNode.addProp('_widgetId', parentTransformHelper.getIdExpression());
+            includeNode.addProp('_widget', builder.identifier('widget'));
+        });
     }
 
-    includeNode.generateCodeForDynamicInclude = (options, codegen) => {
-        var target = options.target;
-        var data = options.data;
 
-        if (!target) {
-            target = builder.memberExpression(builder.identifier('data'), builder.identifier('widgetBody'));
-        }
 
-        if (!data) {
+    // includeNode.generateCodeForDynamicInclude = (options, codegen) => {
-            data = builder.literal(null);
+    //     var target = options.target;
-        }
+    //     var data = options.data;
-
+    //
-        let includeVar = context.importModule('marko_widget_include', this.getMarkoWidgetsRequirePath('marko/widgets/taglib/helpers/include'));
+    //     if (!data) {
-
+    //         data = builder.literal(null);
-        let includeArgs = [
+    //     }
-            target,
+    //
-            builder.identifierOut(),
+    //     let includeVar = context.importModule('marko_widget_include', this.getMarkoWidgetsRequirePath('marko/widgets/taglib/helpers/include'));
-            data
+    //
-        ];
+    //     let includeArgs = [
-
+    //         target,
-        if (parentTransformHelper) {
+    //         builder.identifierOut(),
-            includeArgs = includeArgs.concat([
+    //         data
-                parentTransformHelper.getIdExpression(),
+    //     ];
-                builder.identifier('widget')
+    //
-            ]);
+    //     if (parentTransformHelper) {
-        }
+    //         includeArgs = includeArgs.concat([
-
+    //             parentTransformHelper.getIdExpression(),
-        return builder.functionCall(includeVar, includeArgs);
+    //
-    };
+    //         ]);
+    //     }
+    //
+    //     return builder.functionCall(includeVar, includeArgs);
+    // };
 };

widgets/taglib/TransformHelper/handleWidgetBind.js

@@ -165,7 +165,7 @@ module.exports = function handleWidgetBind() {
         widgetAttrs.id = id;
     }
 
-    let widgetNode = context.createNodeForEl('w-widget', widgetAttrs);
+    let widgetNode = context.createNodeForEl('_widget', widgetAttrs);
     el.wrapWith(widgetNode);
 
     el.setAttributeValue('id', builder.memberExpression(builder.identifier('widget'), builder.identifier('id')));

widgets/taglib/helpers/include.js

@@ -1,23 +0,0 @@
-var isBrowser = typeof window !== 'undefined';
-var normalInclude = require('../../../runtime/include');
-var markoWidgets = require('../../');
-
-module.exports = function include(target, out, data, id, widget) {
-    if (typeof target === 'string') {
-        out.text(target);
-    } else if (target) {
-        normalInclude(target, out, data || widget);
-    } else if (isBrowser) {
-        if (id) {
-            // There is no body content so let's see if we should reuse
-            // the existing body content in the DOM
-            var existingEl = document.getElementById(id);
-            if (existingEl) {
-                var widgetsContext = markoWidgets.getWidgetsContext(out);
-                widgetsContext.addPreservedDOMNode(existingEl, true /* body only */);
-            }
-        } else {
-            throw new Error('Invalid include');
-        }
-    }
-};

widgets/taglib/include-tag.js

@@ -0,0 +1,23 @@
+var isBrowser = typeof window !== 'undefined';
+var normalInclude = require('../../taglibs/core/include-tag');
+var markoWidgets = require('../');
+
+module.exports = function include(input, out) {
+    var target = input._target;
+
+    if (typeof target === 'string') {
+        out.text(target);
+    } else if (target) {
+        normalInclude(input, out);
+    } else if (isBrowser) {
+        var widgetId = input._widgetId;
+
+        // Thereis no body content so let's see if we should reuse
+        // the existing body content in the DOM
+        var existingEl = document.getElementById(widgetId);
+        if (existingEl) {
+            var widgetsContext = markoWidgets.getWidgetsContext(out);
+            widgetsContext.addPreservedDOMNode(existingEl, true /* body only */);
+        }
+    }
+};

widgets/taglib/marko.json

@@ -195,7 +195,7 @@
         },
         "transformer": "./widgets-transformer.js"
     },
-    "<w-widget>": {
+    "<_widget>": {
         "renderer": "./widget-tag.js",
         "@type": "object",
         "@config": "object",

widgets/taglib/widget-tag.js

@@ -1,24 +1,8 @@
-/*
- * Copyright 2011 eBay Software Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
 'use strict';
 var markoWidgets = require('../');
 var extend = require('raptor-util/extend');
 var widgetArgsId = require('../widget-args-id');
-var includeHelper = require('./helpers/include');
+var includeTag = require('./include-tag');
 
 var DUMMY_WIDGET_DEF = {
         elId: function () {
@@ -50,7 +34,10 @@ function preserveWidgetEl(existingWidget, out, widgetsContext, widgetBody) {
 
     if (widgetBody && existingWidget.bodyEl) {
         hasUnpreservedBody = true;
-        includeHelper(widgetBody, out, null, existingWidget.bodyEl.id, existingWidget.bodyEl.id);
+        includeTag({
+            _target: widgetBody,
+            _widgetId: existingWidget.bodyEl.id
+        }, out);
     }
 
     out.endElement();