Re: FAQ (Passing Variables Between Actions); But, Stuck and Need Help
On 11/06/2003 09:02 PM Caroline Jen wrote: I think I am going for the first method that you suggested - create a user bean and store it in a session object at login. My concern is that I use container managed authentication at login. After the container does its job, is there any way other than using an Action that delegates the business tier to search the database and obtain the value of field_of_specialization? If an action has to be involved at this point to form a session object, does it suffer the the disadvantage of being overwritten if the user has more than one browser window opened? If you include a method call in all your actions to check whether the user is logged in, and then whether the session bean exists already, you can determine whether to create the bean or not each time. This won't be affected by the number of browser windows open, since you will only create the user bean once. at the problem - I provide a buttion in editor's page, which is a JSP tile: req:isUserInRole role=editor html:form action=/do/editor/Category html:submitView Articles/html:submit /html:form /req:isUserInRole If the button is clicked, I attempt to use an Action (via the path /editor/Category) to search the database for the field_of_specialization. However, I got this message in the browser: [ServletException in:/article/content/menu.jsp] Cannot retrieve mapping for action /do/editor/Category' and in my struts-config.xml action path=/editor/Category type=org.apache.artimus.article.EditorViewAction forward name=success path=/menu/Find/ /action Sorry but I can't see why that problem should occur from the info you give. Maybe if you start a new thread with a relevant subject title for this then somebody may be able to help. If you could specify exactly when or which page causes the error, it might help too. Adam -- struts 1.1 + tomcat 5.0.12 + java 1.4.2 Linux 2.4.20 RH9 - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
FAQ (Passing Variables Between Actions); But, Stuck and Need Help
Passing variables from one action to another is a frequently asked question. The answer is to use either hidden fields or a session object. The story starts with searching the database. My application offers options to search the database by author, title of the article, article ID, or . I have a drop-down list in my JSP for visitors to make a selection. By clicking on one of those options, the property dispatch is set. And the visitor fills out the text field to set keyValue. With both dispatch and keyValue forwarded to an action; say, Action ONE, the desired articles can be retrieved from the database. So far so good. What I have handled next is the author's page of the web site. An author can only view his own articles and perform update, delete, save, ... functions. I use the hidden field technique to handle it. The property dispatch is arbitrarily set as author (needless to say) and keyValue can be obtained by String username = request.getRemoteUser(); And, html:hidden property=dispatch value=author/ html:hidden property=keyValue value=%=username%/ are forwarded to the same action (Action ONE) for processing. Again, no problem. Now, the application has another user case - editors. An editor only retrieve and view all articles in his/her own field of specialization. I arbitrarily set dispatch as field_of_specialization and use the hidden field technique: html:hidden property=dispatch value=field_of_Specialization/ Nonetheless, the way to get the value the editor's field of specialization is from the database. Because editors are registered members of the web site, the application should be able to look for his/her profile and obtain his/her field of specialization in the database once an editor successfully logs into the web site. Therefore, it takes an action (Action TWO) that tells the business tier to find the keyValue in the database. And should I put the keyValue in a session object. I have tried to handle this situation again and again in many different ways. I am very frustrated and need help -- how does a user go from by clicking a button in a JSP to go to Action TWO (get the keyValue) and then forward this keyValue and html:hidden property=dispatch value=field_of_Specialization/ to Action ONE for retrieving the desired articles from the database? __ Do you Yahoo!? Protect your identity with Yahoo! Mail AddressGuard http://antispam.yahoo.com/whatsnewfree - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: FAQ (Passing Variables Between Actions); But, Stuck and Need Help
On 11/06/2003 08:26 AM Caroline Jen wrote: Passing variables from one action to another is a frequently asked question. The answer is to use either hidden fields or a session object. [snip...] Now, the application has another user case - editors. An editor only retrieve and view all articles in his/her own field of specialization. I arbitrarily set dispatch as field_of_specialization and use the hidden field technique: html:hidden property=dispatch value=field_of_Specialization/ Nonetheless, the way to get the value the editor's field of specialization is from the database. Because editors are registered members of the web site, the application should be able to look for his/her profile and obtain his/her field of specialization in the database once an editor successfully logs into the web site. Therefore, it takes an action (Action TWO) that tells the business tier to find the keyValue in the database. And should I put the keyValue in a session object. One method that I use is to create a user bean and store that in the session at login. This bean could include your editor's field of specialization, so that you don't need an extra action. Secondly, you could drop the Action One by incorporating the field of specialization as a part of one SQL statement, so that you never actually extract the field of specialization from the DB. I.e. something like this: SELECT article_title, article_text FROM app_user, article WHERE app_user.user_name = ? AND app_user.field_of_specialization = article.field_of_specialization Alternatively if you still want to do 2 actions, I have seen people handle it in various ways: (1) get the action-forward in your action and modify the path to add a query_string with your keyValue on it (2) put the keyValue in a cookie (3) as you said, put it in the session. 2 3 have the disadvantage that they could be overwritten if the user has more than one browser window open. HTH Adam -- struts 1.1 + tomcat 5.0.12 + java 1.4.2 Linux 2.4.20 RH9 - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: FAQ (Passing Variables Between Actions); But, Stuck and Need Help
Thank you for the very useful and constructive feedbacks. I think I am going for the first method that you suggested - create a user bean and store it in a session object at login. My concern is that I use container managed authentication at login. After the container does its job, is there any way other than using an Action that delegates the business tier to search the database and obtain the value of field_of_specialization? If an action has to be involved at this point to form a session object, does it suffer the the disadvantage of being overwritten if the user has more than one browser window opened? In regard to the two-action approach that you discussed toward the end of your message, I encountered some problems. If you would take a look at the problem - I provide a buttion in editor's page, which is a JSP tile: req:isUserInRole role=editor html:form action=/do/editor/Category html:submitView Articles/html:submit /html:form /req:isUserInRole If the button is clicked, I attempt to use an Action (via the path /editor/Category) to search the database for the field_of_specialization. However, I got this message in the browser: [ServletException in:/article/content/menu.jsp] Cannot retrieve mapping for action /do/editor/Category' and in my struts-config.xml action path=/editor/Category type=org.apache.artimus.article.EditorViewAction forward name=success path=/menu/Find/ /action -Caroline --- Adam Hardy [EMAIL PROTECTED] wrote: On 11/06/2003 08:26 AM Caroline Jen wrote: Passing variables from one action to another is a frequently asked question. The answer is to use either hidden fields or a session object. [snip...] Now, the application has another user case - editors. An editor only retrieve and view all articles in his/her own field of specialization. I arbitrarily set dispatch as field_of_specialization and use the hidden field technique: html:hidden property=dispatch value=field_of_Specialization/ Nonetheless, the way to get the value the editor's field of specialization is from the database. Because editors are registered members of the web site, the application should be able to look for his/her profile and obtain his/her field of specialization in the database once an editor successfully logs into the web site. Therefore, it takes an action (Action TWO) that tells the business tier to find the keyValue in the database. And should I put the keyValue in a session object. One method that I use is to create a user bean and store that in the session at login. This bean could include your editor's field of specialization, so that you don't need an extra action. Secondly, you could drop the Action One by incorporating the field of specialization as a part of one SQL statement, so that you never actually extract the field of specialization from the DB. I.e. something like this: SELECT article_title, article_text FROM app_user, article WHERE app_user.user_name = ? AND app_user.field_of_specialization = article.field_of_specialization Alternatively if you still want to do 2 actions, I have seen people handle it in various ways: (1) get the action-forward in your action and modify the path to add a query_string with your keyValue on it (2) put the keyValue in a cookie (3) as you said, put it in the session. 2 3 have the disadvantage that they could be overwritten if the user has more than one browser window open. HTH Adam -- struts 1.1 + tomcat 5.0.12 + java 1.4.2 Linux 2.4.20 RH9 - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] __ Do you Yahoo!? Protect your identity with Yahoo! Mail AddressGuard http://antispam.yahoo.com/whatsnewfree - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
