Re: Locking a page?
Hi all, First thanks for the suggestions, after reading what has been posted and giving it more thought this is how I think I am going to handle page locking. 1) when a user enters the page to edit it, I will create a lock in a lock table in my database. This way of someone else whats to edit the same page I can tell them that it is being edited by someone else and just let them view the data as readonly 2) I will use some javascript to keep track of the person doing the edits. I am going to use window.onload to start a reminder timer giving the user say 30 min to do their edits. after the 30 min I will open a dialog which will launch yet another timer. one - if the user ignores the reminder after say 5 min it will reload the page and trigger some cleanup (see 3 below). If the user is not done, closing the dialog will cancel this timed event and let the user keep editing the page 3) I am going to use window.onbeforeunload to find out when a user has left the editing page, and fire an ajax call to clean up the database locks. I've not actually written all the locking code yet just been playing with the timers and onbeforeunload and I think it will work. I'll post some working code if it works or let you all know if it does not work Any dialog about this or other approaches would be great. Jose On Sep 6, 1:07 pm, Jose Galvez [EMAIL PROTECTED] wrote: Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Locking a page?
Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
On 2007-09-06 Jose Galvez wrote: I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. You could look at the model the MoinMoin wiki uses (and probably most wikis). Basically, don't use the database to enforce the edit locking, but rather set an application global lock and timer on a page being edited that expires after some minutes (and make the user aware of it). Then when the time expires, warn the editor that he just lost his lock and will lose his changes permanently (or cause conflict) if he doesn't save/renew ASAP. Meanwhile, other would-be editors receive a page being edited, try again in a few minutes, or deal with conflict message when they try to edit the locked page. As soon as the lock expires you have a race between editors to try and obtain the lock. You could make it more robust with some rotation/priority protocol, but simple is probably better for human page editing. -- _ _ ___ |V|icah |- lliott [EMAIL PROTECTED] http://MicahElliott.com --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
Hi Jose! I am going to face the same problem with the application I am coding, it is a sort of CMS. I have thought about adding a boolean field called lock just as you have used in the past. When a user requests a page to edit and the lock field is not set to true, she can edit the page otherwise the user gets a javascript modal window using Jquery and a plugin stating that the page can be viewed but not edited, the textarea containing the editor is then set to editable = no. When the user sets the page as published and not just saved the page, the lock field is reset and her editor is set also to editable=no This is theoretical, as I am still having problems with the Javascript library I am using and Xinha( editor) and cant test at the moment. On Sep 6, 10:07 pm, Jose Galvez [EMAIL PROTECTED] wrote: Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
This is the plugin I intend to use, it can effectively block user input if needed with notification: http://www.malsup.com/jquery/block/#page On Sep 6, 10:39 pm, voltron [EMAIL PROTECTED] wrote: Hi Jose! I am going to face the same problem with the application I am coding, it is a sort of CMS. I have thought about adding a boolean field called lock just as you have used in the past. When a user requests a page to edit and the lock field is not set to true, she can edit the page otherwise the user gets a javascript modal window using Jquery and a plugin stating that the page can be viewed but not edited, the textarea containing the editor is then set to editable = no. When the user sets the page as published and not just saved the page, the lock field is reset and her editor is set also to editable=no This is theoretical, as I am still having problems with the Javascript library I am using and Xinha( editor) and cant test at the moment. On Sep 6, 10:07 pm, Jose Galvez [EMAIL PROTECTED] wrote: Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
Don't do this. There is no way to make 100% certain that you don't end up with stale locks. Sure, you can have an ajaxy thing that pings the server every minute or so to say, I'm still editing this, but then the user goes off to lunch and everyone is stuck until they get home. Or a malicious user can lock up all your pages forever. If you do do it, make sure your locks are merely advisory (Warning: Karl is editing this page right now.). If your data is simple enough, allow both edits and then merge changes programatically and let the user resolve conflicts (like svn). If it's too complex for that, then just show the diff and let the user merge the changes. On Thu, 2007-09-06 at 13:07 -0700, Jose Galvez wrote: Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
Hmm..then things would be harder than I expected,maybe just warning the user as David suggested would be enough, when the users ignore the warning, tough luck. I wonder how the other CMS apps take care of this problem. On Sep 7, 1:29 am, Jose Galvez [EMAIL PROTECTED] wrote: Hey voltron, I'll take a look at the library, it looks pretty cool. David Turner, makes some really good points and is really the main thing that I''ve worried about. My current site (the one that needs lots of work read I don't like the way I did it) uses a database to keep the locks, which I unlock when the user leaves the page (I'm using javascript thats pretty buggy and doesn't alway work) so I'm left doing occational cleanup on the Lock table. Luckily for this project I have a pretty limited set of users so when I delete locks I'm pretty sure I'm not getting rid of an active lock, but I'm not really fond the the code. Like I said its pretty buggy. What I really need is someway to know when a user leaves the website - but I don't think thats really possible or reliable. Jose Jose voltron wrote: This is the plugin I intend to use, it can effectively block user input if needed with notification: http://www.malsup.com/jquery/block/#page On Sep 6, 10:39 pm, voltron [EMAIL PROTECTED] wrote: Hi Jose! I am going to face the same problem with the application I am coding, it is a sort of CMS. I have thought about adding a boolean field called lock just as you have used in the past. When a user requests a page to edit and the lock field is not set to true, she can edit the page otherwise the user gets a javascript modal window using Jquery and a plugin stating that the page can be viewed but not edited, the textarea containing the editor is then set to editable = no. When the user sets the page as published and not just saved the page, the lock field is reset and her editor is set also to editable=no This is theoretical, as I am still having problems with the Javascript library I am using and Xinha( editor) and cant test at the moment. On Sep 6, 10:07 pm, Jose Galvez [EMAIL PROTECTED] wrote: Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
Hey voltron, I'll take a look at the library, it looks pretty cool. David Turner, makes some really good points and is really the main thing that I''ve worried about. My current site (the one that needs lots of work read I don't like the way I did it) uses a database to keep the locks, which I unlock when the user leaves the page (I'm using javascript thats pretty buggy and doesn't alway work) so I'm left doing occational cleanup on the Lock table. Luckily for this project I have a pretty limited set of users so when I delete locks I'm pretty sure I'm not getting rid of an active lock, but I'm not really fond the the code. Like I said its pretty buggy. What I really need is someway to know when a user leaves the website - but I don't think thats really possible or reliable. Jose Jose voltron wrote: This is the plugin I intend to use, it can effectively block user input if needed with notification: http://www.malsup.com/jquery/block/#page On Sep 6, 10:39 pm, voltron [EMAIL PROTECTED] wrote: Hi Jose! I am going to face the same problem with the application I am coding, it is a sort of CMS. I have thought about adding a boolean field called lock just as you have used in the past. When a user requests a page to edit and the lock field is not set to true, she can edit the page otherwise the user gets a javascript modal window using Jquery and a plugin stating that the page can be viewed but not edited, the textarea containing the editor is then set to editable = no. When the user sets the page as published and not just saved the page, the lock field is reset and her editor is set also to editable=no This is theoretical, as I am still having problems with the Javascript library I am using and Xinha( editor) and cant test at the moment. On Sep 6, 10:07 pm, Jose Galvez [EMAIL PROTECTED] wrote: Hi all, I'm hunting for advice. I am looking for a way to lock a webpage so that only only one person at a time can edit database data. Here is the scenario, I have a database with a limited number of users who have write access to the database, what I'd like to do is lock the editing page so that if one of my users is editing a page then the other users will not be able to edit the same page(data) at the same time. I know that this is what transactions are for in a database, but what I want to avoid is two people looking at the same unedited data and then editing it. I guess what I really want to is lock a database when I use starts editing the data. The issues are: 1) How to make sure someone exits the edit mode nicely? what happens if they enter the edit page, do nothing and just close the browser, I don't what to leave the table locked 2) if the table is locked I would still like to let users view the data in real time, jut not edit it. I've used a lock table for this in the past, but the issue that I've never figured out is how to make sure someone still needs the lock. Again number (1) from above. I hope that this makes sense, I'll be using sqlalchemy and postgres on the back end thanks for any and all advice jose --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
Re: Locking a page?
On Thu, 2007-09-06 at 17:07 -0400, David Turner wrote: Don't do this. There is no way to make 100% certain that you don't end up with stale locks. Sure, you can have an ajaxy thing that pings the server every minute or so to say, I'm still editing this, but then the user goes off to lunch and everyone is stuck until they get home. If you're using JS anyway, I'd use a combination of short-refresh server-side locks (maybe 30s interval, with AJAX polling from the client to keep the lock alive) and a keystroke client-side lock with a longer (30m?) interval. If the user doesn't interact with the form for 30m, consider it unlocked and alert the user. Or a malicious user can lock up all your pages forever. Don't allow malicious users to edit your pages? =) Cliff --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups pylons-discuss group. To post to this group, send email to pylons-discuss@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/pylons-discuss?hl=en -~--~~~~--~~--~--~---
