I've had a read of similar questions and not found a simple answer. I need to store a date value that has nothing to do with my models.
For example, let's say I have a screen which displays a graph of user activity based on all records being created after a specific date. I need to store that date somewhere. An admin user will change this initial date depending on whether they need to look at the last six months, or the last year etc. That setting will then be the same for all admin users. So it's not an admin user setting.
I thought about a config file, but then it needs to be writable and these seem idea for values that are being looked up but not edited on a regular basis?
Any advice appreciated..
Related
I am not sure what is better perfomance whise so I ask you guys.
The problem is following:
I have a system where each User gets a certain amount of credit for certain events. So I gave my User an attribute named creditscore that gets altered on those events. Everything works well. But now I want the user to actually see what he did when and how much credit he got for this.
What would be better here:
Saving the whole history in a text attribute and add lines for each event
or
writing an extra model associated with the user and create an instance for every event.
or
or
something way different?
Since there are several events per user per day it would be either a huge text or a huge amount of instances. What would be better looking at website performance.
You absolutely do NOT want to store the history in a text attribute. Management of this will be a nightmare as will querying the data.
You could create a CreditEvent model and store the individual events in there. That would work fine.
However, before you start, check rubygems.org and ruby-toolbox.com to see if someone has already done the hard work. I know of at least one gem that seems to do exactly what you want to do:
https://github.com/merit-gem/merit
In my rails application,After login a user has to create a timesheet entry.The time of creation of the entry is currently my server time.Whereas i want it to be the time of the timezone from where the entry is made i.e if entry is made from any other country.I'm using rails 3 and after searching the web also exact solution cannot be achieved.
Thanx
You can't automatically determine the user's timezone, but you can allow them to choose their own timezone. Then you can set Time.zone = ActiveSupport::TimeZone(offset) before calling update and everything should work correctly. You could also save each user's preference for time zone in your user model.
I'm not sure if it's possible to do this in Rails as the issue is getting the physical location of a user.
It may be worth using JavaScript to populate a (hidden?) field with the current time, which should be taken from user's local machine. You could then explicitly set the created_at field to be this value.
Intrigued to know if Rails can get around this somehow...
If you want, take a look to this question : transform time into local time in Ruby on Rails
And : http://www.wetware.co.nz/blog/2009/07/rails-date-formats-strftime/
Maybe it can helps you.
I'm working on a Rails application that's kind of like a blog. Users create Entries. I'm trying to work out how to handle time storage and display. I've read this writeup about Rails timezone support.
It's great but it doesn't cover what my app needs to do. It only looks at cases where you want to convert stored time to the current logged in user's time zone. In contrast, the effect I want is...
A user creates an entry in California at 10:00 a.m.
A couple years later he moves to New York and then at some point looks at his old entry. The "created" date should say "10:00 a.m." He doesn't care about time zones. He just wants to know what time of day he felt like it was when he wrote the entry.
If he then edits the Entry in New York the displayed "modified" date is, again, his subjective time of day when he made the edit. (Let's assume he went to "preferences" and changed his time zone setting when he moved.)
Also, for the sake of thoroughness, the app should be able to report the "real" absolute time when an Entry was created or updated.
(Note -- my imaginary user is a guy, but for women it should work roughly the same way.)
The way I'm thinking of implementing it is...
Have the attributes User#time_zone, Entry#created_at_utc, and Entry#updated_at_utc in addition to the standard created_at and updated_at.
The user selects their time zone from a menu when they sign up. (They can change it later if they want.)
The app uses User#time_zone to store created_at and updated_at in the user's subjective local time. If it's 10:00 a.m. for them, the app writes "10:00 a.m." to the DB.
The app also saves the current UTC time in the aforementioned _utc fields to deal with the last requirement above.
Is that a good way to do it? Is there a better way?
The two roads you can take are:
Store a timezone (UTC) in the user account as well as in every post - update the post's timezone along with the updated_at field whenever the user changes the post (if he or she has changed timezones).
Store the timezone only in the user account. When the user changes timezones, update every post that belongs to the user and add/subtract to the created_at/updated_at dates.
The first option seems like the cleanest option to take. For this you would only have to create a new method in your post record:
def locational_updated_at
updated_at + timezone.seconds
end
Where timezone is an integer containing the seconds since UTC.
If you can, you should avoid storing two different sets of timestamps, and you should avoid storing any non-UTC dates. Both of these things will lead to confusion. I'm not completely sure I understand what you're doing (though I like your idea of subjective time), but wouldn't it be enough to just attach a time zone to every post, and always use that zone to display the times? It would default to the time zone set in the author's account, so he could change it when he moved cross-country without affecting previous posts.
I think that's all you need--to attach a time zone to every post. Is that sufficient? Or am I missing some part of this?
I'm developing a webapp that allows the editing of records. There is a possibility that two users could be working on the same screen at a time and I want to minimise the damage done, if they both click save.
If User1 requests the page and then makes changes to the Address, Telephone and Contact Details, but before he clicks Save, User2 requests the same page.
User1 then clicks save and the whole model is updated using TryUpdateModel(), if User2 simply appends some detail to the Notes field, when he saves, the TryUpdateModel() method will overwrite the new details User1 saved, with the old details.
I've considered storing the original values for all the model's properties in a hidden form field, and then writing a custom TryUpdateModel to only update the properties that have changed, but this feels a little too like the Viewstate we've all been more than happy to leave behind by moving to MVC.
Is there a pattern for dealing with this problem that I'm not aware of?
How would you handle it?
Update: In answer to the comments below, I'm using Entity Framework.
Anthony
Unless you have any particular requirements for what happens in this case (e.g. lock the record, which of course requires some functionality to undo the lock in the event that the user decides not to make a change) I'd suggest the normal approach is an optimistic lock:
Each update you perform should check that the record hasn't changed in the meantime.
So:
Put an integer "version" property or a guid / rowversion on the record.
Ensure this is contained in a hidden field in the html and is therefore returned with any submit;
When you perform the update, ensure that the (database) record's version/guid/rowversion still matches the value that was in the hidden field [and add 1 to the "version" integer when you do the update if you've decided to go with that manual approach.]
A similar approach is obviously to use a date/time stamp on the record, but don't do that because, to within the accuracy of your system clock, it's flawed.
[I suggest you'll find fuller explanations of the whole approach elsewhere. Certainly if you were to google for information on NHibernate's Version functionality...]
Locking modification of a page while one user is working on it is an option. This is done in some wiki software like dokuwiki. In that case it will usually use some javascript to free the lock after 5-10 minutes of inactivity so others can update it.
Another option might be storing all revisions in a database so when two users submit, both copies are saved and still exist. From there on, all you'd need to do is merge the two.
You usually don't handle this. If two users happen to edit a document at the same time and commit their updates, one of them wins and the other looses.
Resources lockout can be done with stateful desktop applications, but with web applications any lockout scheme you try to implement may only minimize the damage but not prevent it.
Don't try to write an absolutely perfect and secure application. It's already good as it is. Just use it, probably the situation won't come up at all.
If you use LINQ to SQL as your ORM it can handle the issues around changed values using the conflicts collection. However, essentially I'd agree with Mastermind's comment.
I am developing a gallery which allows users to post photos, comments, vote and do many other tasks.
Now I think that it is correct to allow users to unsubscribe and remove all their data if they want to. However it is difficult to allow such a thing because you run the risk to break your application (e.g. what should I do when a comment has many replies? what should I do with pages that have many revisions by different users?).
Photos can be easily removed, but for other data (i.e. comments, revisions...) I thought that there are three possibilities:
assign it to the admin
assign it to a user called "removed-user"
mantain the current associations (i.e. the user ID) and only rename user's data (e.g. assign a new username such as "removed-user-24" and a non-existent e-mail such as "noreply-removed-user-24#mysite.com"
What are the best practices to follow when we allow users to remove their accounts? How do you implement them (particularly in Rails)?
I've typically solved this type of problem by having an active flag on user, and simply setting active to false when the user is deleted. That way I maintain referential integrity throughout the system even if a user is "deleted". In the business layer I always validate a user is active before allowing them to perform operations. I also filter inactive users when retrieving data.
The usual thing to do is instead of deleting them from a database, add a boolean flag field and have it be true for valid users and false for invalid users. You will have to add code to filter on the flag. You should also remove all relevant data from the user that you can. The primary purpose of this flag is to keep the links intact. It is a variant of the renaming the user's data, but the flag will be easier to check.
Ideally in a system you would not want to "hard delete" data. The best way I know of and that we have implemented in past is "soft delete". Maintain a status column in all your data tables which ideally refers to the fact whether the row is active or not. Any row when created is "Active" by default; however as entries are deleted; they are made inactive.
All select queries which display data on screen filter results for only "active records". This way you get following advantages:
1. Data Recovery is possible.
2. You can have a scheduled task on database level, which can take care of hard deletes of once in a way; if really needed. (Like a SQL procedure or something)
3. You can have an admin screen to be able to decide which accounts, entries etc you'd really want to mark for deletion
4. A temperory disabling of account can also be implemented with same solution.
In prod environments where I have worked on, a hard delete is a strict No-No. Infact audits are maintained for deletes also. But if application is really small; it'd be upto user.
I would still suggest a "virtual delete" or a "soft delete" with periodic cleanup on db level; which will be faster efficient and optimized way of cleaning up.
I generally don't like to delete anything and instead opt to mark records as deleted/unpublished using states (with AASM i.e. acts as state machine).
I prefer states and events to just using flags as you can use events to update attributes and send emails etc. in one foul swoop. Then check states to decide what to do later on.
HTH.
I would recommend putting in a delete date field that contains the date/time the user unsubscribed - not only to the user record, but to all information related to that user. The app should check the field prior to displaying anything. You can then run a hard delete for all records 30 days (your choice of time) after the delete date. This will allow the information not to be shown (you will probably need to update the app in a few places), time to allow the user to re-subscribe (accidental or rethinking) and a scheduled process to delete old data. I would remove ALL information about the member and any related comments about the member or their prior published data (photos, etc.)
I am sure it changing lot since update with Data Protection and GDPR, etc.
the reason I found this page as I was looking for advice because of new Apply policy on account deletion requirements extended https://developer.apple.com/news/?id=i71db0mv
We are using Ruby on Rails right now. Your answers seem a little outdated? or not or still useful right now
I was thinking something like that
create a new table “old_user_table” with old user_id , First name, Second name, email, and booking slug.
It will allow keep all users who did previous booking. And deleted their user ID in the app. We need to keep all records for booking for audit purpose in the last 5 years in the app.
the user setup with this app, the user but never booking, then the user will not transfer to “old_user_table” cos the user never booking.
Does it make sense? something like that?