Cannot get back a command in a flow ..

**yfmoan** · Jun 21st, 2005, 09:46 PM

Hi ,
l cannot get back a command that put in a flow scope , according to Keith , it suppose to "stay there for the life of the flow".

l wish to do the following ,

l first search a list of publishers for edit , after a successful search , l pick a publisher for edit , show the edit page then edit and submit . After a successful edit , l wish to immediately display back the original search for user experience ...so l need the original command --> googleSortCommand for my case , but l cannot get it , may be my code problem .... below is my codes snippet ,

Code:

public class BookRelatedActions extends AbstractLibraryFormAction &#123;

       private static final String GOOGLE_SORT_COMMAND = "googleSortCommand";

       public BookRelatedActions&#40;&#41; &#123;

	      setFormObjectName&#40;GOOGLE_SORT_COMMAND&#41;;
	      setFormObjectClass&#40;GoogleSortCommand.class&#41;;
	      //l set <property name="formObjectScopeAsString" value="flow"/> in xxx.servlet.xml
       &#125;

...
       public Event SearchPublisher&#40;RequestContext context&#41; throws Exception &#123;

              GoogleSortCommand googleSortCommand = &#40;GoogleSortCommand&#41;context.getFlowScope&#40;&#41;.get&#40;GOOGLE_SORT_COMMAND&#41;;

              String publisherName = googleSortCommand.getKeyword&#40;&#41;;
              String sortColumn = googleSortCommand.getSortColumn&#40;&#41;;

              System.out.println&#40;"-------"+publisherName+"--------"&#41;;
              System.out.println&#40;"^^^^^^^^"+sortColumn+"^^^^^^^^"&#41;;

              if&#40;publisherName != null&#41;&#123;

                   Map model = getLibrary&#40;&#41;.findPublishersByNameWithTotal&#40;googleSortCommand&#41;;
                   ArrayList publishers = &#40;ArrayList&#41;model.get&#40;"_resultset"&#41;;

                   if &#40;publishers.size&#40;&#41; < 1&#41; &#123;
                        // no item found
                        writeMessage&#40;context,"NoPublihserFound","no.publisher.found"&#41;;

                        return success&#40;&#41;;
                   &#125;
                   // multiple items found
		   context.getRequestScope&#40;&#41;.setAttribute&#40;"Publishers", model&#41;;

		   return success&#40;&#41;;
	      &#125;

	      return success&#40;&#41;;
        &#125;

&#125;

Code:

System.out.println&#40;"-------"+publisherName+"--------"&#41;;
System.out.println&#40;"^^^^^^^^"+sortColumn+"^^^^^^^^"&#41;;

show nulls ... no original form object return.

bookRelated-flow.xml,

Code:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE webflow PUBLIC "-//SPRING//DTD WEBFLOW//EN"
	"http&#58;//www.springframework.org/dtd/spring-webflow.dtd">

<webflow id="bookRelated.Flow" start-state="bookRelated.start">

	<view-state id="bookRelated.start" view="bookRelated.view">
	        <transition on="showPublisherForm" to="AddPublisherForm"/>
                <transition on="searchPublisherById" to="publisher.Update.Flow"/>
		<transition on="deletePublisher" to="DeletePublisher"/>

		<transition on="searchAuthor" to="SearchAuthor">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchPublisher" to="SearchPublisher">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchSubject" to="SearchSubject">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchOtherTitle" to="SearchOtherTitle">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchSeries" to="SearchSeries">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchNote" to="SearchNote">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
	</view-state>

	<view-state id="AddPublisherForm" view="publisher.Create">
		<transition on="add" to="bindAndValidate.SaveForm"/>

		<transition on="searchAuthor" to="SearchAuthor">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchPublisher" to="SearchPublisher">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchSubject" to="SearchSubject">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchOtherTitle" to="SearchOtherTitle">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchSeries" to="SearchSeries">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchNote" to="SearchNote">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
	</view-state>

	<action-state id="bindAndValidate.SaveForm">
	        <action bean="publisherActions" method="bindAndValidate"/>
		<transition on="success" to="SavePublisher"/>
		<transition on="error" to="AddPublisherForm"/>
	</action-state>

	<action-state id="SavePublisher">
	        <action name="Save" bean="publisherActions"/>
		<transition on="Save.success" to="AddPublisherForm"/>
		<transition on="Save.error" to="AddPublisherForm"/>
	</action-state>

	<subflow-state id="publisher.Update.Flow" flow="publisher.Update.Flow">
		<attribute-mapper>
			<input value="$&#123;sourceEvent.parameters.id&#125;" as="id" type="long"/>
		</attribute-mapper>
                <transition on="finish" to="bookRelated.start"/>
		<transition on="finish.edit.publisher" to="SearchPublisher">
		        <action bean="bookRelatedActions" method="bindAndValidate"/>
                </transition>
		<transition on="_SearchAuthor" to="SearchAuthor"/>
                <transition on="_SearchPublisher" to="SearchPublisher"/>
                <transition on="_SearchSubject" to="SearchSubject"/>
                <transition on="_SearchOtherTitle" to="SearchOtherTitle"/>
                <transition on="_SearchSeries" to="SearchSeries"/>
                <transition on="_SearchNote" to="SearchNote"/>
		<transition on="error" to="bookRelated.start"/>
	</subflow-state>

	<action-state id="DeletePublisher">
	        <action bean="publisherActions"/>
		<transition on="success" to="bookRelated.start"/>
		<transition on="error" to="bookRelated.start"/>
	</action-state>

	<action-state id="SearchAuthor">
	        <action bean="bookRelatedActions"/>
	        <transition on="success" to="bookRelated.start"/>
	</action-state>

	<action-state id="SearchPublisher">
	        <action bean="bookRelatedActions"/>
	        <transition on="success" to="bookRelated.start"/>
	</action-state>

	<action-state id="SearchSubject">
	        <action bean="bookRelatedActions"/>
	        <transition on="success" to="bookRelated.start"/>
	</action-state>

	<action-state id="SearchOtherTitle">
	        <action bean="bookRelatedActions"/>
	        <transition on="success" to="bookRelated.start"/>
	</action-state>

	<action-state id="SearchSeries">
	        <action bean="bookRelatedActions"/>
	        <transition on="success" to="bookRelated.start"/>
	</action-state>

	<action-state id="SearchNote">
	        <action bean="bookRelatedActions"/>
	        <transition on="success" to="bookRelated.start"/>
	</action-state>
	
</webflow>

subflow - publisher.Update-flow.xml

Code:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE webflow PUBLIC "-//SPRING//DTD WEBFLOW//EN"
	"http&#58;//www.springframework.org/dtd/spring-webflow.dtd">

<webflow id="publisher.Update.Flow" start-state="SearchPublisherById">

	<action-state id="SearchPublisherById">
		<action bean="publisherActions"/>
		<transition on="success" to="publisher.edit"/>
		<transition on="error" to="finish"/>
	</action-state>

	<view-state id="publisher.edit" view="publisher.Update">
		<transition on="edit" to="bindAndValidate.EditForm"/>
		<transition on="back" to="finish"/>
		<transition on="searchAuthor" to="_SearchAuthor">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchPublisher" to="_SearchPublisher">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchSubject" to="_SearchSubject">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchOtherTitle" to="_SearchOtherTitle">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchSeries" to="_SearchSeries">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
		<transition on="searchNote" to="_SearchNote">
			<action bean="bookRelatedActions" method="bindAndValidate"/>
		</transition>
	</view-state>

	<action-state id="bindAndValidate.EditForm">
	        <action bean="publisherActions" method="bindAndValidate"/>
		<transition on="success" to="EditPublisher"/>
		<transition on="error" to="publisher.edit"/>
	</action-state>

	<action-state id="EditPublisher">
	        <action bean="publisherActions"/>
		<transition on="success" to="finish.edit.publisher"/>
		<transition on="error" to="publisher.edit"/>
	</action-state>

        <end-state id="finish"/>
	<end-state id="finish.edit.publisher"/>
        <end-state id="_SearchAuthor"/>
        <end-state id="_SearchPublisher"/>
        <end-state id="_SearchSubject"/>
        <end-state id="_SearchOtherTitle"/>
        <end-state id="_SearchSeries"/>
        <end-state id="_SearchNote"/>
</webflow>

moon

**klr8** · Jun 22nd, 2005, 04:20 AM

As far as I can see, it seems to be working since you actually get something back from "context.getFlowScope().get(GOOGLE_SORT_COMMAN D)", otherwise you would have gotten a NPE on "googleSortCommand.getKeyword();".

Erwin.

**yfmoan** · Jun 22nd, 2005, 04:36 AM

Nope , it was filtered by if(publisherName != null) ... and display an successView ( l direct all success or error to successView for convenient ..hihi )
Some of my print out ,

Code:

l did the printout&#58;
              System.out.println&#40;googleSortCommand&#41;;
              System.out.println&#40;"-------"+subjectName+"--------"&#41;;
              System.out.println&#40;"^^^^^^^^"+sortColumn+"^^^^^^^^"&#41;;
results&#58;

&#40;first search&#41;

org.yourschool.library.domain.command.GoogleSortCommand@1debcf3

-------%--------

^^^^^^^^publisherName^^^^^^^^

&#40;after success edit&#41;

org.yourschool.library.domain.command.GoogleSortCommand@152e7a4

-------null--------

^^^^^^^^null^^^^^^^^

it seem to be two different instances for the commands.

moon

**klr8** · Jun 22nd, 2005, 05:51 AM

Look at your code:

1) First you do "GoogleSortCommand googleSortCommand = (GoogleSortCommand)context.getFlowScope().get(GOOG LE_SORT_COMMAND);"

2) Next you do "String publisherName = googleSortCommand.getKeyword();"

Since that is not throwing a NPE, it means that googleSortCommand is present in the flow scope. The fact that you have different form objects in your flow scope is probably because you're doing 'setupForm' multiple times.

Erwin

**yfmoan** · Jun 22nd, 2005, 07:54 AM

Yes , l don't know why there is another command too , l got a new empty content command.

l don't have any setupForm , what you see in BookRelatedActions is all , actually l have just one method now - SearchPublisher (just for testing) , you can also see it in my bookRelated-flow.xml too .... , another object - PublisherActions , just a CRUD actions for Publisher that you can see in another thread post ..

moon

**yfmoan** · Jun 22nd, 2005, 10:26 AM

If l remove the line ,
<action bean="bookRelatedActions" method="bindAndValidate"/>

Code:

   <subflow-state id="publisher.Update.Flow" flow="publisher.Update.Flow"> 
      <attribute-mapper> 
         <input value="$&#123;sourceEvent.parameters.id&#125;" as="id" type="long"/> 
      </attribute-mapper> 
                <transition on="finish" to="bookRelated.start"/> 
                <transition on="finish.edit.publisher" to="SearchPublisher"/> 
                *********** remove the code here *************
                <transition on="_SearchAuthor" to="SearchAuthor"/> 
                <transition on="_SearchPublisher" to="SearchPublisher"/> 
                <transition on="_SearchSubject" to="SearchSubject"/> 
                <transition on="_SearchOtherTitle" to="SearchOtherTitle"/> 
                <transition on="_SearchSeries" to="SearchSeries"/> 
                <transition on="_SearchNote" to="SearchNote"/> 
                <transition on="error" to="bookRelated.start"/> 
   </subflow-state>

then l got a NPE ...

The code above is so simple that l don't know where to find the error ....hihi .... l am dying ....

moon

**yfmoan** · Jun 22nd, 2005, 08:43 PM

Hi , Erwin
l found the answer , my original xxx-library.xml was using

Code:

<bean id="flowExecutionManager"
    class="org.springframework.web.flow.execution.servlet.ServletFlowExecutionManager">
       <property name="storage">
              <bean class="org.springframework.web.flow.execution.
                  servlet.HttpSessionContinuationFlowExecutionStorage"/>
       </property>
</bean>

after l change it to

Code:

<bean id="flowExecutionManager"
      class="org.springframework.web.flow.execution.servlet.ServletFlowExecutionManager">
		<property name="storage">
			<bean class="org.springframework.web.flow.execution.servlet.HttpSessionFlowExecutionStorage"/>
		</property>
</bean>

it is return the same form object now , l got the original command object.
but now the question , why there is a different between HttpSessionContinuationFlowExecutionStorage and HttpSessionFlowExecutionStorage ? , if this is the case , that means we cannot use HttpSessionContinuationFlowExecutionStorage if we want to get back the original command ?

moon

**yfmoan** · Jun 22nd, 2005, 09:13 PM

Immediately there is another problem (may be mine)
l do paging using own make tag , refer to http://forum.springframework.org/showthread.php?t=14458 , the mechanism l was using to retrieve the page , pageSize , sortColumn ,...are simply using,

Code:

    public void initProperties(){

           HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
           this.parameters = RequestUtil.getRequestParameterMap(request);

           String Page = (String)parameters.get(PAGE);
           this.page = Integer.parseInt(Page);

           String PageSize = (String)parameters.get(PAGE_SIZE);
           this.pageSize = Integer.parseInt(PageSize);

           this.listSize = ((List)((Map)request.getAttribute(modelName)).get("_resultset")).size();
           this.totalElements =  ((Integer)((Map)request.getAttribute(modelName)).get("_totalElements")).intValue();

           this.previousPageLink = UrlEncoder.encode(makePreviousPageParameters(parameters));
           this.nextPageLink = UrlEncoder.encode(makeNextPageParameters(parameters));

    }

although l found the problem above , l got another exception immediately ,

Code:

java.lang.NumberFormatException: null
	java.lang.Integer.parseInt(Unknown Source)
	java.lang.Integer.parseInt(Unknown Source)
	org.simplePage.web.tags.GoogleTag.initProperties(GoogleTag.java:60)
....

l cannot get those parameter back to feed the GoogleTag .... l guess because of those parameters are in the flow scope not the request scope , if my guess is true , than l have to modify my codes to retrieve those parameters from SWF , this will make my paging codes depend on SWF API , how to solve this problem ?

l think one of the SWF's ability is chaining actions , because it can store the "history" inside a flow (what ever it store in RequestContext , Event ,.....) , but if you put something (parameters for example) inside a flow , then you must have a way to let something out (parameters for example..

) after few chaining steps to show results ....

what do you think ?

moon

**yfmoan** · Jun 23rd, 2005, 09:07 PM

Guess 1.
l think other paging tag like displaytag or valuelist will subject to the same problem if they are using similar retrieving method ... how they know where to get those parameters ?

Q1.
Even though l pass those parameters to my paging tag manually by the help of the action (BookRelatedActions) ,

Code:

Map parameters = context.getSourceEvent&#40;&#41;.getParameters&#40;&#41;;
context.getRequestScope&#40;&#41;.setAttribute&#40;"_parameters", parameter&#41;;
context.getRequestScope&#40;&#41;.setAttribute&#40;"Publishers", model&#41;;

it still fail my paging tag , because the parameters from SourceEvent is an UnmodifiableMap , then how can we do paging using SWF ?

moon

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