[TAPESTRY-2060] ExternalAsset bugs

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.1.3
• Fix Version/s: 4.1.5
• Assignee: Andreas Andreou
• Reporter: sorphi
• Created: 18/Jan/08 09:57
• Updated: 18/Jan/08 16:23
• Resolved: 18/Jan/08 16:23

Description

When i prepared to hack asset "clientValidationScript" in form.jwc from "classpath:/dojo-0.4.3/dojo3.js" to "/mypath/dojo-0.4.3/dojo3.js" for some reasons (main is that i hate private assets,)))

error happend:

java.lang.NullPointerException
Stack Trace:

• $AssetFactory_1178ab8d243._getStrategy(Ljava/lang/Object;)Lorg/apache/tapestry/asset/AssetFactory;($AssetFactory_1178ab8d243.java:???)
• $AssetFactory_1178ab8d243.createAsset(Lorg/apache/hivemind/Resource;Lorg/apache/hivemind/Location;)Lorg/apache/tapestry/IAsset;($AssetFactory_1178ab8d243.java:???)
• $AssetFactory_1178ab8d094.createAsset(Lorg/apache/hivemind/Resource;Lorg/apache/hivemind/Location;)Lorg/apache/tapestry/IAsset;($AssetFactory_1178ab8d094.java:???)
• org.apache.tapestry.util.PageRenderSupportImpl.writeExternalScripts(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(PageRenderSupportImpl.java:291)
• org.apache.tapestry.util.PageRenderSupportImpl.writeBodyScript(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(PageRenderSupportImpl.java:320)
• org.apache.tapestry.services.impl.DefaultResponseBuilder.writeBodyScript(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(DefaultResponseBuilder.java:349)
• $ResponseBuilder_1178ab8d204.writeBodyScript(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V($ResponseBuilder_1178ab8d204.java:???)
• $ResponseBuilder_1178ab8d0a6.writeBodyScript(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V($ResponseBuilder_1178ab8d0a6.java:???)
• org.apache.tapestry.html.Body.renderComponent(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(Body.java:62)
• org.apache.tapestry.AbstractComponent.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(AbstractComponent.java:725)
• org.apache.tapestry.services.impl.DefaultResponseBuilder.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRender;Lorg/apache/tapestry/IRequestCycle;)V(DefaultResponseBuilder.java:179)
• org.apache.tapestry.AbstractComponent.renderBody(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(AbstractComponent.java:539)
• org.apache.tapestry.html.Shell.renderComponent(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(Shell.java:124)
• org.apache.tapestry.AbstractComponent.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(AbstractComponent.java:725)
• org.apache.tapestry.services.impl.DefaultResponseBuilder.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRender;Lorg/apache/tapestry/IRequestCycle;)V(DefaultResponseBuilder.java:179)
• org.apache.tapestry.BaseComponent.renderComponent(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(BaseComponent.java:107)
• org.apache.tapestry.AbstractComponent.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(AbstractComponent.java:725)
• org.apache.tapestry.services.impl.DefaultResponseBuilder.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRender;Lorg/apache/tapestry/IRequestCycle;)V(DefaultResponseBuilder.java:179)
• org.apache.tapestry.BaseComponent.renderComponent(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(BaseComponent.java:107)
• org.apache.tapestry.AbstractComponent.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRequestCycle;)V(AbstractComponent.java:725)
• org.apache.tapestry.services.impl.DefaultResponseBuilder.render(Lorg/apache/tapestry/IMarkupWriter;Lorg/apache/tapestry/IRender;Lorg/apache/tapestry/IRequestCycle;)V(DefaultResponseBuilder.java:177)
• org.apache.tapestry.AbstractPage.renderPage(Lorg/apache/tapestry/services/ResponseBuilder;Lorg/apache/tapestry/IRequestCycle;)V(AbstractPage.java:249)
  .....

In org.apache.tapestry.form.FormSupportImpl.java , line 568-573
IAsset clientScript = _form.getAsset("clientValidationScript");

if (clientScript != null)

{ _pageRenderSupport.addExternalScript(_form, clientScript.getResourceLocation()); }

before hacking, clientScript is PrivateAsset. now in my case, is an ExternalAsset instance.

here clientScript.getResourceLocation() returns always null, because ExternalAsset 's constructor: (ExternalAsset .java line 36-41)

public ExternalAsset(String URL, Location location)

{ super(null, location); _url = URL; }

So _pageRenderSupport.addExternalScript(_form, null), and so, in org.apache.tapestry.util.PageRenderSupportImpl.java line 289-291:
Resource scriptLocation = (Resource) _externalScripts.get;

IAsset asset = _assetFactory.createAsset(scriptLocation, null);

will throw a NPE in enhanced AssetFactory because null scriptLocationResource can't match a strategy.

I think in constructor of ExternalAsset , let resourceLocation null is arbitrary. should change to :
super(new ExternalResource(URL, null), location);

And add another construtor to corresponse creation in org.apache.tapestry.asset.DefaultAssetFactory (line 55-58):
public IAsset createAsset(Resource resource, Location location)

{ return new ExternalAsset(resource.getPath(), location); // can change to new ExternalAsset(resource, location) if that. }

After all, let me pass a user defind asset to Form.jwc like as Shell.jwc is a better way. )