First time user long time reader. I have thoroughly looked for an explanation for the problem I'm having via the mighty search engine Google, but alas I have failed to produce any significant insight.
I need to be able to ensure that a model form is not reloaded with invalid data. Since the model stored in memory on the server is edited directly with the parameters of the web form first, and THEN checked for validity, without additional code invalid model data will ALWAYS be sent back to the form. This is less than desirable to me. My question is this: how do I ensure this doesn't happen?
What I'm thinking is I need some mechanism for saving the state of the object before it's modified with the parameters sent from the web form, and then after a failed validation restore the object to it's previous, correct and unmodified state of being.
Help!
Thanks,
Les
The object isn't actually modified in the db if validation fails, even though the object is in an invalid state in the form ... the thinking behind this is that the user wants to see the errors they made so they can correct them.
If you don't want that to be the case, then just read back the object with a WhateverObject.find(x) and assign it to the variable that the form is referencing and it will 'restore' the object to its previous unmodified state.
To add to what concept47 said you can also get the value for a particular field using
object.field_was
Have a look at ActiveRecord::Dirty for details (http://ar.rubyonrails.org/classes/ActiveRecord/Dirty.html)
Using that you could retrieve the original values for just those fields that had validation errors.
Related
In my application i got the error as con't update stale object. I don't know about this object. When it will create and why it was called a stale object. I want to know. Is it used in Only in ROR or other languges are also uses, this object and purpose?
According to the documentation:
http://api.rubyonrails.org/classes/ActiveRecord/StaleObjectError.html
Reason of Stale object exception is:
Record is stale when it's being saved in another query after instantiation, for example, when two users edit the same wiki page and one starts editing and saves the page before the other.
Solution: To avoid this exception use the locking system:
http://api.rubyonrails.org/classes/ActiveRecord/Locking/Optimistic.html
In my application multiple threads to be able to edit the same work -> version -> element record. its detecting error and raising the suitable error.
I typically did to handle the error:
I print a flash message such as "Sorry, please try after someone time, someone else editing this working version element".
element.lock_version = Document::Element.find(element.id).lock_version
element.save!
For example, such as detecting that one edit changed the element's type, where as the other edit changed the element's name by different creator, and then code of the two record should be merged done in one save.
In general, I used to element.reload to fetch a fresh version of the element.
worked fine!!
I am looking to have a user enter in a URL to an image on a form. I already have this built. I would like for two different things to happen, but I was wondering if I could somehow combine them.
When the user submits the form, I would like the URL to be validated, not only that it takes on a valid url format, but that it actually exists.
I would also like to set an integer in the database depending on the type of document the URL points to. If it is an image, I would like an integer field on the record (let's call it 'file_type') to be set to 1. If it is not an image, I would like the validation to fail.
Is there any way to validate the URL while also collecting data for the record? I ask this because I believe it makes much more sense for the server to make the request once rather than twice, once for validation, and once for storing file type.
Is this possible? What would you suggest?
Thanks!
I needed to create a input mask for a jQuery datepicker in my Rails app, where the first form field uses m/d/yy format and the datepicker populates a hidden input with the proper database format.
I was using SimpleForm, and so I extended my own input so that the input is preceded by the mask.
I got everything set up and when checking out the browser, it all just worked well before I thought I would be done.
The form ends up with two inputs for the same attribute, each with the same id and name. I never thought this would work. Checking the development log I only see one date getting submitted, the second of the two which is the one that has the proper format for the database.
Is this all okay? Should I take some extra steps even though this appears to work fine, and more importantly, can someone explain what's going on under the hood that results in this behavior?
Thanks!!
Rails uses the Hash params to store fields submitted. When you declare two or more inputs using the same name, it happens the same as if you do something like
h=Hash.new
h[:name]="foo"
h[:name]="bar"
Result is bar because the foo was overwritten. So the "winner" is always the field value which the browser last appended to postdata.
But if I where you, I would not rely on the browser that the second field gets appended at last.
Im trying to integrate a content filtering API. My plan was to use pre/post validators but I've lost may way somehow.
What i need to do is send the values to the content filtering service. If the response comes back that the content has been filtered it will also return a modified value for the field (basic profanity filtering... matches are replace with asterisks). Thats all well and good i can throw validation errors no problem - simple stuff.
However i dont want just throw errors. What needs to happen is that validation errors are thrown as normal, but the values are modified in the form for re-display.
Basically if someone posts something naughty i want them to get a validation error saying their post has been modified, they can re-submit the now "clean" post, or they can go about editing it to make it clean without the word replacements.
But do clean on a validator either throws an error OR returns cleaned values, not both. How can i go about implementing both? This will be used on many different forms with many different field names, so modifying methods on the form or a form base class isnt really an option - it needs to happen in the validation sub-framework somehow.
You can adjust this plugin for your needs http://www.symfony-project.org/plugins/WebPurifyPlugin
Let's say I have a table called positions (as in job positions). On the position show page I display all the detail about the job - awesome. At the bottom I need the prospective applicant to input their professional license # before continuing onto the next page which is the actual applicant creation form. I also need to take that license # and have it populate that field on the applicant form (again on the proceeding page).
I realize there are a couple ways to do this. Possibly the more popular option would be to store that value in the session. I am curious how to do this in the simplest manner?
My idea:
Create a table specifically for license #'s.
Add a small form on the position show page to create license # (with validation)
Store newly created license in session - not sure what to put in which controller?
On applicant creation form populate from session the license #.
This would assume applicants only have one license.
Thoughts?
Appreciate the help!
Don't store this in the session! Pass that as an hidden field.
Let's say the user starts the form, then open the form again in a new window or something... then the session variable would be shared between the two forms. Other problems would occur if the cookie gets removed (session expire, user clear cache...)
This is not good. The best way is using a POST variable. GET works as well but messes up the URL
Seems like a good idea. As for #3, for whatever controller is called in the transition from 2 -> 4, that would be the controller where you store the session, as such:
session[:license_number] = your_license_number_information
From there, it can be called the same way (session[:license_number]) to get it.
The hidden field is safer for data persistence. However is not not then coded in the HTML output? That can be a great data security issue.
This is a trade-off to be considered.