Struct state between pages in an application
OK, I've made this disclaimer before, but it still applies: I'm really new when it comes to CF, so I request that you please keep that in mind as you read this. I don't claim that as an excuse for not searching out the answers on my own, but I've been unable to find an explanation of this behavior in the CF docs so far. So anyway... I've got this form, and I want to use the selected/input values from the form to call a stored procedure that is within a package in an Oracle database for processing. But, before passing the values to the database, I want the user to be able to confirm the selections that they've made before sending the information to the database. So, at the beginning of the page that displays the form, I check to see if the structure is defined, and if it's not, I create it. (I realize that what you're about to read may not make sense if it's not the best way to do this, but it was the only way that I could figure out to do it, so this is how it currently works...I'm open to suggestions) So, on the form page, the action is GET, and on the action page, I first populate all of the properties of the structure with the URL parameters that have been passed from the form, by evaluating their values in the URL. I then display the users selections, by outputting the values of the structure p! roperties. All of this to this point works fine. The fact that it works fine, suggests to me that structures reside in memory on the CF server, and can persist between templates in an application. So, based on that assumption, I also assumed that the properties of the structure would be available on the NEXT page as well. The action page for the form, has two links at the bottom of it, after all of the values that the user has selected are displayed for confirmation...one link is a back button, that allows the user to go back to the form and make any necessary corrections to their input, and the other is a link to another template that actually process the form by passing all of the properties of the structure to the stored procedure in the database for processing. The first thing I do in this template, is check for the existence of the structure, to make sure that it's values can be passed to the stored procedure. This is where my problem comes up. Every time I click! the link to go to this template for processing, I get the me! ssage that gets displayed if the structure does not exist (it's a message that I've inserted to let the user know that there was an error, due to the fact that the structure cannot be found, and processing cannot continue). What am I doing wrong? Why is the server not finding this structure? Am I not defining it properly to be available across multiple templates or something like that? Any thoughts would be greatly appreciated. The code for checking for the existence of the structure is below. Thanks in advance. cfif not isDefined(myStructure) pThe structure does not exist. Blah blah blah./p cfelse ... /cfif ::YEX:: ))) /* || Robert D. Yexley || Oracle Programmer/Analyst || Northrop Grumman IT || Contractor - Wright Research Site MIS || Det-1 AFRL/WSI Bldg. 45 Rm. 062 || (937) 255-1984 || [EMAIL PROTECTED] || ))) */ ~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk FAQ: http://www.thenetprofits.co.uk/coldfusion/faq This list and all House of Fusion resources hosted by CFHosting.com. The place for dependable ColdFusion Hosting.
RE: Struct state between pages in an application
Like any other variable in the local scope, the structure you're creating ceases to exist when the page finishes processing. You'll need to put it in a persistent scope (Session, Client) or in some other way pass it to the next page (serialize it with WDDX and put it in a hidden form variable, deserializing it on the next page; using Uncle Ben's CF_embedformfields tag; etc.) You'll probably want to use Session variables. 1. Remember your CFLOCKs 2. You should probably delete the structure in Session when you get to your processing page so it's not hanging around. OK, I've made this disclaimer before, but it still applies: I'm really new when it comes to CF, so I request that you please keep that in mind as you read this. I don't claim that as an excuse for not searching out the answers on my own, but I've been unable to find an explanation of this behavior in the CF docs so far. So anyway... I've got this form, and I want to use the selected/input values from the form to call a stored procedure that is within a package in an Oracle database for processing. But, before passing the values to the database, I want the user to be able to confirm the selections that they've made before sending the information to the database. So, at the beginning of the page that displays the form, I check to see if the structure is defined, and if it's not, I create it. (I realize that what you're about to read may not make sense if it's not the best way to do this, but it was the only way that I could figure out to do it, so this is how it currently works...I'm open to suggestions) So, on the form page, the action is GET, and on the action page, I first populate all of the properties of the structure with the URL parameters that have been passed from the form, by evaluating their values in the URL. I then display the users selections, by outputting the values of the structure p! roperties. All of this to this point works fine. The fact that it works fine, suggests to me that structures reside in memory on the CF server, and can persist between templates in an application. So, based on that assumption, I also assumed that the properties of the structure would be available on the NEXT page as well. The action page for the form, has two links at the bottom of it, after all of the values that the user has selected are displayed for confirmation...one link is a back button, that allows the user to go back to the form and make any necessary corrections to their input, and the other is a link to another template that actually process the form by passing all of the properties of the structure to the stored procedure in the database for processing. The first thing I do in this template, is check for the existence of the structure, to make sure that it's values can be passed to the stored procedure. This is where my problem comes up. Every time I click! the link to go to this template for processing, I get the me! ssage that gets displayed if the structure does not exist (it's a message that I've inserted to let the user know that there was an error, due to the fact that the structure cannot be found, and processing cannot continue). What am I doing wrong? Why is the server not finding this structure? Am I not defining it properly to be available across multiple templates or something like that? Any thoughts would be greatly appreciated. The code for checking for the existence of the structure is below. Thanks in advance. cfif not isDefined(myStructure) pThe structure does not exist. Blah blah blah./p cfelse ... /cfif ~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/index.cfm?sidebar=listsbody=lists/cf_talk FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Structure your ColdFusion code with Fusebox. Get the official book at http://www.fusionauthority.com/bkinfo.cfm
RE: Struct state between pages in an application
I don't think you can store complex objects like structures in the client scope without first serializing them into a wddx packet... ( which would be similar to passing it in a form, just different management of the packet )... however... I think Al's right, sessions are probably your best bet... I'd change the action in your form from GET to POST and put this on your intermediary action page: cfif isdefined(form.myrequiredfield) cflock scope=session type=exclusive timeout=10 cfset session.mystruct = duplicate(form) /cflock cflocation url=#cgi.path_info# addtoken=nocfabort cfelse cflock scope=session type=readonly timeout=10 cfif structkeyexists(session,mystruct) cfset mystruct = duplicate(session.mystruct)/cfif /cflock /cfif cfif isdefined(mystruct) ... output the structure and the form to go to the next page here... cfelse ... custom error message ... /cfif The reason for using POST instead of GET is to insulate the data from a mangled or over-long url for whatever reason. If it sees your required form field, it coppies the data into the request scope, then relocates to the current page without the form, so that if the user refreshes the page, they won't get the annoying do you want to repost the form message. It then grabs the data from the session scope and if everything is okay, they can hit the next button and on the following page, you can grab the data from the request scope again, as in the else clause above. hth S. Isaac Dealey Certified Advanced ColdFusion 5 Developer www.turnkey.to 954-776-0046 Like any other variable in the local scope, the structure you're creating ceases to exist when the page finishes processing. You'll need to put it in a persistent scope (Session, Client) or in some other way pass it to the next page (serialize it with WDDX and put it in a hidden form variable, deserializing it on the next page; using Uncle Ben's CF_embedformfields tag; etc.) You'll probably want to use Session variables. 1. Remember your CFLOCKs 2. You should probably delete the structure in Session when you get to your processing page so it's not hanging around. OK, I've made this disclaimer before, but it still applies: I'm really new when it comes to CF, so I request that you please keep that in mind as you read this. I don't claim that as an excuse for not searching out the answers on my own, but I've been unable to find an explanation of this behavior in the CF docs so far. So anyway... I've got this form, and I want to use the selected/input values from the form to call a stored procedure that is within a package in an Oracle database for processing. But, before passing the values to the database, I want the user to be able to confirm the selections that they've made before sending the information to the database. So, at the beginning of the page that displays the form, I check to see if the structure is defined, and if it's not, I create it. (I realize that what you're about to read may not make sense if it's not the best way to do this, but it was the only way that I could figure out to do it, so this is how it currently works...I'm open to suggestions) So, on the form page, the action is GET, and on the action page, I first populate all of the properties of the structure with the URL parameters that have been passed from the form, by evaluating their values in the URL. I then display the users selections, by outputting the values of the structure p! roperties. All of this to this point works fine. The fact that it works fine, suggests to me that structures reside in memory on the CF server, and can persist between templates in an application. So, based on that assumption, I also assumed that the properties of the structure would be available on the NEXT page as well. The action page for the form, has two links at the bottom of it, after all of the values that the user has selected are displayed for confirmation...one link is a back button, that allows the user to go back to the form and make any necessary corrections to their input, and the other is a link to another template that actually process the form by passing all of the properties of the structure to the stored procedure in the database for processing. The first thing I do in this template, is check for the existence of the structure, to make sure that it's values can be passed to the stored procedure. This is where my problem comes up. Every time I click! the link to go to this template for processing, I get the me! ssage that gets displayed if the structure does not exist (it's a message that I've inserted to let the user know that there was an error, due to the fact that the structure cannot be found, and processing cannot continue). What am I doing wrong? Why is the server not finding this structure? Am I not defining it properly to be
