FreeMarker template error: The following has evaluated to null or missing: ==> [in template "component://snj2/template/catalog/ProductDetail.ftl" at line 389, column 19] ---- Tip: It's the step after the last dot that caused this error, not those before it. ---- Tip: If the failing expression is known to be legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)?? ---- ---- FTL stack trace ("~" means nesting-related): - Failed at: #if (product.originalImageUrl?string?... [in template "component://snj2/template/catalog/ProductDetail.ftl" at line 389, column 13] ---- Java stack trace (for programmers): ---- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:134) at freemarker.core.UnexpectedTypeException.newDesciptionBuilder(UnexpectedTypeException.java:80) at freemarker.core.UnexpectedTypeException.<init>(UnexpectedTypeException.java:43) at freemarker.core.BuiltInsForMultipleTypes$stringBI._eval(BuiltInsForMultipleTypes.java:709) at freemarker.core.Expression.eval(Expression.java:81) at freemarker.core.ExistenceBuiltins$ExistenceBuiltIn.evalMaybeNonexistentTarget(ExistenceBuiltins.java:52) at freemarker.core.ExistenceBuiltins$has_contentBI._eval(ExistenceBuiltins.java:112) at freemarker.core.ExistenceBuiltins$has_contentBI.evalToBoolean(ExistenceBuiltins.java:119) at freemarker.core.AndExpression.evalToBoolean(AndExpression.java:36) at freemarker.core.ParentheticalExpression.evalToBoolean(ParentheticalExpression.java:35) at freemarker.core.IfBlock.accept(IfBlock.java:49) at freemarker.core.Environment.visit(Environment.java:326) at freemarker.core.Environment.visit(Environment.java:332) at freemarker.core.Environment.visit(Environment.java:332) at freemarker.core.Environment.process(Environment.java:305) at org.apache.ofbiz.base.util.template.FreeMarkerWorker.renderTemplate(FreeMarkerWorker.java:263) at org.apache.ofbiz.widget.model.HtmlWidget.renderHtmlTemplate(HtmlWidget.java:167) at org.apache.ofbiz.widget.model.HtmlWidget$HtmlTemplate.renderWidgetString(HtmlWidget.java:216) at org.apache.ofbiz.widget.model.HtmlWidget.renderWidgetString(HtmlWidget.java:140) at org.apache.ofbiz.widget.model.ModelScreenWidget$PlatformSpecific.renderWidgetString(ModelScreenWidget.java:1321) at org.apache.ofbiz.widget.model.ModelScreenWidget.renderSubWidgetsString(ModelScreenWidget.java:98) at org.apache.ofbiz.widget.model.ModelScreenWidget$Section.renderWidgetString(ModelScreenWidget.java:280) at org.apache.ofbiz.widget.model.ModelScreen.renderScreenString(ModelScreen.java:164) at org.apache.ofbiz.widget.model.ScreenFactory.renderReferencedScreen(ScreenFactory.java:214) at org.apache.ofbiz.widget.model.ModelScreenWidget$IncludeScreen.renderWidgetString(ModelScreenWidget.java:780) at org.apache.ofbiz.widget.model.ModelScreenWidget.renderSubWidgetsString(ModelScreenWidget.java:98) at org.apache.ofbiz.widget.model.ModelScreenWidget$Section.renderWidgetString(ModelScreenWidget.java:280) at org.apache.ofbiz.widget.model.ModelScreenWidget.renderSubWidgetsString(ModelScreenWidget.java:98) at org.apache.ofbiz.widget.model.ModelScreenWidget$DecoratorSection.renderWidgetString(ModelScreenWidget.java:906) at org.apache.ofbiz.widget.model.ModelScreenWidget$SectionsRenderer.render(ModelScreenWidget.java:127) at org.apache.ofbiz.widget.model.ModelScreenWidget$DecoratorSectionInclude.renderWidgetString(ModelScreenWidget.java:943) at org.apache.ofbiz.widget.model.ModelScreenWidget.renderSubWidgetsString(ModelScreenWidget.java:98) at org.apache.ofbiz.widget.model.ModelScreenWidget$Section.renderWidgetString(ModelScreenWidget.java:280) at org.apache.ofbiz.widget.model.ModelScreenWidget.renderSubWidgetsString(ModelScreenWidget.java:98) at org.apache.ofbiz.widget.model.ModelScreenWidget$Section.renderWidgetString(ModelScreenWidget.java:280) at org.apache.ofbiz.widget.model.ModelScreen.renderScreenString(ModelScreen.java:164) at org.apache.ofbiz.widget.model.ScreenFactory.renderReferencedScreen(ScreenFactory.java:214) at org.apache.ofbiz.widget.model.ModelScreenWidget$DecoratorScreen.renderWidgetString(ModelScreenWidget.java:860) at org.apache.ofbiz.widget.model.ModelScreenWidget.renderSubWidgetsString(ModelScreenWidget.java:98) at org.apache.ofbiz.widget.model.ModelScreenWidget$Section.renderWidgetString(ModelScreenWidget.java:280) at org.apache.ofbiz.widget.model.ModelScreen.renderScreenString(ModelScreen.java:164) at org.apache.ofbiz.widget.renderer.ScreenRenderer.render(ScreenRenderer.java:136) at org.apache.ofbiz.widget.renderer.ScreenRenderer.render(ScreenRenderer.java:98) at org.apache.ofbiz.widget.renderer.macro.MacroScreenViewHandler.render(MacroScreenViewHandler.java:157) at org.apache.ofbiz.webapp.control.RequestHandler.renderView(RequestHandler.java:1001) at org.apache.ofbiz.webapp.control.RequestHandler.doRequest(RequestHandler.java:653) at org.apache.ofbiz.webapp.control.ControlServlet.doGet(ControlServlet.java:213) at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:720) at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466) at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391) at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318) at org.apache.ofbiz.product.category.CatalogUrlServlet.doGet(CatalogUrlServlet.java:153) at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.ofbiz.webapp.control.ContextFilter.doFilter(ContextFilter.java:324) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.ofbiz.content.content.ContentUrlFilter.doFilter(ContentUrlFilter.java:99) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.ofbiz.product.category.CatalogUrlFilter.doFilter(CatalogUrlFilter.java:338) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528) at org.apache.coyote.ajp.AbstractAjpProcessor.process(AbstractAjpProcessor.java:873) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748)
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Secrets of mental math

by Arthur Benjamin and Michael Shermer

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Description

Secrets of Mental Math will have you thinking like a math genius in no time. Get ready to amaze your friends—and yourself—with incredible calculations you never thought you could master, as renowned “mathemagician” Arthur Benjamin shares his techniques for lightning-quick calculations and amazing number tricks. This book will teach you to do math in your head faster than you ever thought possible, dramatically improve your memory for numbers, and—maybe for the first time—make mathematics fun.

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Product Details

  • Three Rivers Press Brand
  • 9780307338402 ISBN-13:
  • 0307338401 ISBN-10:
  • 0307338401 ISBN-10
  • 9780307338402 ISBN-13
  • New Condition
  • Hardback Media
  • 5 business days Generally Ships in
  • 5.13 in * 0.66 in * 7.92 in Dimensions:
  • 1 lb Weight: