rails form fields_for serialize hash - serialization

I need to create a check list for a comment form on which users to notify about a comment.
I have a comment model and i have a column called comment_meta which i want to store as a serialize hash.
My comment form has a fields_for comment_meta example;
<%= f.fields_for :comment_meta do |comment_form| %>
<%= comment_form.check_box(contact.id) %>
<% end %>
The params being passed are "comment_meta"=>{"155"=>"0", "156"=>"1", "157"=>"0"}},
but my db is saving an empty hash.
The field type for comment_meta is a text.
Is there a way to save this?

Your comment_meta hash seems to be a 'key-value pair' of ids and Boolean values, respectively. If this is true, then you may be better off going with a users_comment_metas 'through' table.
You would benefit from restructuring to this methodology because:
db indexing is fast - rails hash serialization/parsing to and from the db is slow (unless your using postgres's h-store, but thats another story)
Dynamic reporting about all data in your db will be much more intuitive/query-able as a developer attempting to display readable reports (which is very important at my job at least).
Your goal of using Rails' built in form helpers will be much easier.
If you truly want to go the hash route you've suggested, there could be a variety of things preventing it from saving. Here's how I would troubleshoot:
First make sure you have the line 'serialize comment_meta, Hash' in your Comment model.
Remove ALL validations you may have in the Comment model for testing purposes.
Now, type 'debugger' (no quotes) in your controller create and/or update
action in your comments_controller (or the controller you are
requesting from the form)
when you hit your debugger statement in your terminal, type the words
'eval comment_params' to check the comment params you've submitted (I am assuming you are using the strong parameters gem, seeing as you typed 'ruby-on-rails-4' in your tags for this post).
The hash should have this structure as you've suggested above (if it looks different,
something is wrong in your form, or you have strong paramters set up incorrectly, more info here):
"comment_meta"=>{"155"=>"0", "156"=>"1", "157"=>"0"}
type 'n' until you've passed the line initializing a new object with the params
#comment = Comment.new(comment_params)
Now type 'eval #comment' to see your new object, and then type 'eval #comment.comment_meta' to see if the hash is being stored. If it's returning nil, then type 'eval #comment.valid?'. If it returns true, then type #comment.errors to see what is wrong, and fix accordingly.
If all else fails, make sure you can do a manual assignment of any given hash to comment_meta of a new Comment object in your rails console:
#comment = Comment.new()
#comment.comment_meta = {"test"=>"1"}
#comment.save!
I hope this gets you on the right track.

Related

Rails Displaying Flash Messages from Model

I'm trying to display some error messages from my model in Rails. Currently, when an exception is caught in my test model and raised, the messages are returned as expected in the errors scope of my object. The messages are returned as follows:
{:key1=>["Your key needs to be different."],
:key2=>["Another exception"]}
This is perfect, as the correct exceptions are being thrown for the correct errors. What I'm trying to do now is bind these messages to the flash scope so that I can display them on my view. In my controller, when I have an exception, I then bind it to the flash[:error] scope as follows:
flash[:error] = #test.errors.messages
render :new
Upon doing this, my errors are bound to the flash scope, but when I output them on my view, they are displayed as follows:
[:error, {:key1=>["Your key needs to be different."], :key2=>["Another exception"]}]
All I'd like to do is display each one of these messages so that they look to be like:
Your key needs to be different.
Another exception.
Notice that in the above example, all that will be rendered is the message text.
Will you please point me in the right direction as to what I need to change either in my controller or in my view to achieve the desired output above?
Thank you in advance.
The one place I immediately see for improvement is in the hash you're passing.
If there's not a specific reason you're wrapping your strings in an array, you can eliminate the array:
{
:key1 => "Somebody poisoned the watering hole!",
:key2 => "There's a snake in my boot."
}
That will both simplify your code and eliminate the two-dimensional array you didn't seem to be intending to create.
If there is a reason you're wrapping your strings in an array (multiple messages per key?), you'll need to revisit your iterator; the way it's written now, it's only going to display the first string for any given key.
I noticed that when I looped over #test.errors.messages in the following construct, I ended up with a 2-Dimensional array:
[:key1, ["Your key needs to be different."]]
[:key2, ["Another exception"]]
Since this is a multidimensional array, I was able to then simply loop over the array in my erb and get the value to display as requested in my question:
<% for i in flash[:error] %>
<%= i[1].first %><br />
<% end %>
Returns on the screen:
Your key needs to be different.
Another exception.
I'm always open to suggestions, so if there's a better way to handle this, then please advise! Otherwise, this does work for me.

rails user input with <script>, stored, and displayed

I have an application that collect user input and store to DB and show back to user.
One user entered "alert(1)" into the name field and saved it into DB.
Whenever the name is displayed, the page will be broken.
I know how to fix that input only with validation for input, and h() for output.
However, I have so many input fields and so many outputs that accept users' text.
Is there any simple way to prevent this happening(i.e. overriding params method, etc)?
I also want to know how you expert guys are dealing with this problem?
As of Rails 3, my understanding was that embedded ruby code was html escaped by default. You don't need to use h() to make it that way. That is, if you use <%= "<script>a=1/0;</script>" %> in a view, the string is going to be made html safe, and so the script doesn't execute. You would have to specifically use raw() or something similar to avoid it - which you should naturally not do unless you're really confident about the contents.
For output, Rails 3 automatically html-encode all text unless I use raw() method.
For input, How about making a common validator and apply to all fields that are text or string? Is it desirable?
http://api.rubyonrails.org/classes/ActiveModel/Validator.html
class MyValidator < ActiveModel::Validator
def validate(record)
record.class.columns.each do |c|
if c.type==:text || c.type == :string
record.errors.add c.type, "script tag is not allowed" if c[/<script[^>]*>/]
end
end
end
end

What's a good way to insert a resource id into the params of another resource?

I'm really new to programming, so I'm having trouble explaining this -- please forgive.
I have a Document model and a Note model in my rails app. A note belongs to a document, and a document has many notes -- the foreign key in the notes table is document_id.
On my document show page, I have a form for a note which uses a :content attribute as a text_area field.
What I'd like to do is pass the document's id into the note params so the note would have both the :content the user submits alng with the :document_id based on the document_path.
Currently I'm adding the :document_id into the note's params hash using a hidden_field form helper, and sending the whole thing to the NotesController, but I hope there's a cleaner / perhaps easier way.
If this makes sense, can someone suggest a better way to do this? Thank you.
In your routes have something like
resources :documents do
resources :notes
end
Then you should be adding a note via this route
/documents/5/notes/new
Then in your NotesController have
def create
#document = Document.find(params[:document_id])
#note = #document.notes.build(params[:note])
if #note.save
# Blah
else
# Blah
end
end
(In no way has this been tested - but it gives you an idea of how to do it in a RESTFUL style without hidden fields)

Best way to hook into a Rails 3 page lifecycle

I have the following scenario: I am adapting a edit in place library to be able to display formatted values after the value is edited on an input field.
For that, I want to store the id for some fields being rendered on a given controller action to be served via AJAX whenever needed.
I want to be able to do the following in a view:
<%= edit_in_place #object, :attribute do |value|
"Formatted display value is #{value}"
end
%>
So, I generate a UUID for the control being rendered:
<input ... data-uuid="27b52850-d68f-012e-5dc8-28373723e63c" ...>
The ultimate goal is to keep a FormattingRules hash that would take the block being passed and assign it to the UUID so I could later on, after the user has edited the value, call an AJAX method to format the value:
http://server/format/27b52850-d68f-012e-5dc8-28373723e63c?value=My+Value
The following code is triggered:
def show
block = BestInPlace::FormattingRules[params[:id]]
render :text => block.call(params[:value])
end
And the cod returns:
Formatted display value is My Value
Which is great. With this, I can hide the edit in place input and display the formatted value.
Everything works already, however the FormattingRules hash is growing indefinitely and never being emptied.
My question is: is there a way I can hook into the Rails lifecycle and make this hash more granular (per page or session, maybe?) and make sure it's gone after the page is no longer being used?

Can you remove the _snowman in Rails 3?

I'm building an app on Rails 3 RC. I understand the point behind the _snowman param (http://railssnowman.info/)...however, I have a search form which makes a GET request to the index. Therefore, submitting the form is creating the following query string:
?_snowman=☃&search=Box
I don't know that supporting UTF encoding is as important as a clean query string for this particular form. (Perhaps I'm just too much of a perfectionist...hehe) Is there some way to remove the _snowman param for just this form? I'd rather not convert the form to a POST request to hide the snowman, but I'd also prefer it not be in my query string. Any thoughts?
You can avoid the snowman (now a checkmark) in Rails 3 by.... not using Rails for the search form. Instead of using form_tag, write your own as outlined in:
Rails 3 UTF-8 query string showing up in URL?
Rails helpers are great unless they're not helping. Do-it-yourself is good as long as you understand the consequences, and are willing to maintain it in the future.
I believe the snowman has to be sent over the wire to ensure your data is being encoded properly, which means you can't really remove the snowman input from forms. Since, it's being sent in your GET request, it will have to be appended to the URL.
I suppose you could write some javascript to clean up the URL once the search page loads, or you could setup a redirect to the equivalent URL minus the snowman. Both options don't really feel right to me.
Also, it doesn't seem there is any way to configure Rails to not output it. If you really wanted to get rid of it, you could comment out those lines in Rails' source (the committed patches at the bottom of railssnowman.info should lead you to the files and line numbers). This adds some maintenance chores for you when you upgrade Rails. Perhaps you can submit a patch to be able to turn this off?
EDIT: Looks like they just switched it to what looks like a checkmark instead of a snowman.
EDIT: Oops, back to a snowman.
In Rails 4.1 you can use the option :enforce_utf8 => false to disable utf8 input tag.
However I want to use this in Rails 3, so I monkey-patched my Rails. I put the following in the config/initializers directory.
# allow removing utf8 using enforce_utf8, remove after Rails 4.1
module ActionView
module Helpers
module FormTagHelper
def extra_tags_for_form(html_options)
authenticity_token = html_options.delete("authenticity_token")
method = html_options.delete("method").to_s
method_tag = case method
when /^get$/i # must be case-insensitive, but can't use downcase as might be nil
html_options["method"] = "get"
''
when /^post$/i, "", nil
html_options["method"] = "post"
token_tag(authenticity_token)
else
html_options["method"] = "post"
tag(:input, :type => "hidden", :name => "_method", :value => method) + token_tag(authenticity_token)
end
enforce_utf8 = html_options.delete("enforce_utf8") { true }
tags = (enforce_utf8 ? utf8_enforcer_tag : ''.html_safe) << method_tag
content_tag(:div, tags, :style => 'margin:0;padding:0;display:inline')
end
end
end
end