Rails plugin: form_assistant

Thanks for the plugin. One glitch: No matter what I do, I can’t get the syntax for specifying the form action to work. Am I just being dense?

I was definitely being dense. I’m working with hobo, which doesn’t currently provide support for multi-model forms. I grabbed this plugin to deal with the form_for / fields_for builder issue. I was getting a cryptic series of error messages that had me pulling my hair out. That’s why I thought I wasn’t specifying the action correctly.

Hobo has a built-in user model that I’m trying to extend. It’s very helpful. I’m trying to create a signup form that captures a bunch of data. My app is in the health 2.0 space—I can’t say much more. Hobo does validations that puked on the association “user has_one account”. The error message that I finally figured out was “got HashWithIndifferentAccess, exepected Account”. Since I will be adding more models, I looked at the Presenter pattern. It made for a really clean view, but I’m stuck dealing with hobo user model issues. The main issue is that I don’t understand it ; ) It uses a lifecycle for user that provides hooks like after_create. I’m sure I’ll sort it out eventually.

Any tips on how I might deal with the data type mismatch issue in cases where a presenter doesn’t make sense? Is there a way for the “form_assistant, fields_for” to send the account object that I defined instead of the hash that contains a single instance of said object?

Thanks for the help!

@Danny -

Sorry for the confusion. I’ve made some significant changes to this plugin since this post was written, but it’s for the better. You can find the up-to-date examples, configuration, etc. on the README.

Regarding your issue with inline_error_form_assistant_for. You’re right, it is gone in the master branch. Now, you get all of the goodness from using form_assistant_for. But it’s a little different.

Now, the form helpers are formatted with templates (partials) so you are able to do what you want with how they’re presented. It’s much more extensible. Here’s a snippet so you can see all of the variables that get handed to each partial:

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locals = { 
  :element => element, 
  :label => label, 
  :errors => errors, 
  :tip => tip, 
  :helper => helper
}

By default the form helpers will be looking for a template in app/views/forms that matches the name of the helper (so a “text_field” helper would look for app/views/forms/_text_field.html.erb). To get started with templates, run:

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$ rake form_assistant:install

That will setup the app/views/forms directory with some basic templates. Oh, and if you have a custom template that you’d rather use, just pass it to the helper:

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form.text_field :title, :template => 'custom_template'

Again, you can find all of this in the README. Also, if (for whatever reason) you don’t want to use the new and improved version of this plugin, I’ve tagged the old version that is described in this post. You can find it here.

Hope that helps. And please let me know if you have any other issues.

Thanks!

p.s. i have a little suggestion. It would be great to be able to assign to the template if a field is required. Then you are able to change the template (add an required star for example) if a field is required.

@Danny -

It didn’t take me long to decide on this one. I do think it’s worth having the option to mark a field as required, so now you can.

It makes sense, as labels shouldn’t be the only means to indicate required fields (especially since they can be turned off).

As you might expect, use it like this:

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form.text_field :title, :required => true

That will hand a local variable named ‘required’ over to the template, so you can check that and act accordingly. And to be clear, this defaults to false.

Thanks for the suggestion!

Ryan,

Hi, I want to use form_assistant to render error messages next to the fields that they refer to.

So I need to edit the _text_field.html.erb partial to show the error message. This may be me being stupid, but how can I find the form’s object (eg @user) and the particular field being rendered ?

I can hardcode

<%= @user.errors['password'] %>

and it works, but really I need to find the forms object and the field name in _text_field.html.erb.

I have used the debugger but can’t see anything in scope that would provide the model object or field.

Maybe I have missed something obvious but can you give an example ? It might enhance the (good) tutorial too.

Thanks.

Ryan,

I found that the call to <= errors %> in the partial was not working in my project, even though <= error_messages_for :user %> worked.

Now my project is a bit cluttered with all sorts of plugins (restful_authentication came with lots of them), so I simplified the problem by creating a new test rails project, added your plugin and it worked exactly as you say.

This is an opportunity for me to learn a bit more ruby by looking at how your plugin works and at the ActionView code, so I’ll drop you a note when I find out what my problem is.

(The method has_errors? defined in form_assistant.rb always returns false so the errors collection is never initialized.)

Thanks again.

@Jon -

I see your issue, and I’m glad you’ve found a resolution.

Regarding your question about the form_assistant trying to get at the model object by using a symbol or a string, I’m a little hesitant to alter how it currently behaves. Currently, it’s using the #object method, which will return the object if it exists or find it using a name or symbol if it doesn’t.

I realize it was behaving unexpectedly, but I don’t know if that’s an issue with my plugin or if this was cascaded down from how Rails behaves, since my plugin just uses Rails’ object helper to get at the errors—it doesn’t implement its own logic in that regard.

At any rate, I will be sure to investigate this a little further to make sure I’m not causing issues on my end.

Thanks for the catch and best of luck.

And just a tip… if you design your application RESTfully, you can do:

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<% form_assistant_for @user do |form| %>
  ...
<% end %>

It sure beats explicitly passing in the path. I realize there are those edge cases where it’s mandatory to do that, and if this is one of those cases, please ignore me :-)

@Zac -

Firstly, thanks for the kind words.

Secondly, you have an awesome site! I wish I was capable of creating something that simple. It’s amazing how a single line can be so classy. Unfortunately, it’s something only designers can appreciate. I took a similar approach on my personal github page, but even it ended up more than I wanted. Simplicity truly is a gift.

Secondly, you’re right, there currently isn’t any way (without hacking) to set a default class for all fields. However, I wrote a plugin called input_css that automatically sets a class name based on the “type” of field. For instance, a text_field would get a class of “text”. A submit_button would get a class of “submit”. And the same deal for check boxes, radio buttons, etc. While that’s not a direct solution to your problem, it may help. It’s now mandatory on all of my projects.

In the meantime, I’ll think about adding support for that, but I don’t want to get too crazy with the features. And based on the simplicity of your web site, I’m sure you understand :-)

Thanks for the feedback!

Oops, I messed the formatting there. Let’s try again…

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def form_assistant_for(record_or_name_or_array, *args, &proc)
  if args[0]
    args[0].update(:html => {:class=>"standard_form"}) unless args[0][:html] && args[0][:html].has_key?(:class)
  end
  super
end