# Still Stumbled on First things in trying RubyOnRails

**URL:** <https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985>\
**Category:** Rails\
**Created:** [May 9, 2006, 8:02am UTC](https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985 "2006-05-09T08:02:56Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Ling](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c2a13f/32.png) [@Ling](https://www.ruby-forum.com/u/Ling)\
**Post date:** [May 9, 2006, 8:02am UTC](https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985/1 "2006-05-09T08:02:56Z")

</div>

Still Stumbled on First things in trying RubyOnRails

> **[Top Ruby on Rails Tutorials - Digital Media Minute](https://www.digitalmediaminute.com/article/1816/top-ruby-on-rails-tutorials)**
>
> A former student asked me a few days ago how I learned Ruby on Rails. The answer was that I simply read a lot of great tutorials. So in the spirit of sharing, here is the tutorial I found most useful: Intro to Ruby on Rails – Scott Chow offers his...

> **[Radar - O’Reilly](https://www.oreilly.com/radar/)**
>
> Now, next, and beyond: Tracking need-to-know trends at the intersection of business and technology

[http://instantrails.rubyforge.org/tutorial/index.html](http://instantrails.rubyforge.org/tutorial/index.html)

[http://rails.homelinux.org/](http://rails.homelinux.org/)

I had tried the first of the top 12 tutorials and got stuck after adding  
a new field â??category\_idâ?in the table recipes, introduced  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\views\recipe\edit.rhtml,  
and modified  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\controllers\recipe\_controller  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\models\category  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\models\recipe

I log into [http://localhost:3000/category/list](http://localhost:3000/category/list), chose an item, and when  
I hit the â??Editâ? button, error message occurred.

I then went on to modify  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\views\recipe\list  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\views\recipe\edit

And now I couldnâ??t even log into [http://localhost:3000/category/list](http://localhost:3000/category/list).

After some discussions in the forum, I removed the database, re-created  
a database â??cookbook2â? that resembled â??cookbookâ?, and copied all the  
codes from â??cookbookâ? into the â??cookbook2â? directory.

With the full set of codes in place, and a new, empty database, I went  
about creating, editing, deleting categories. No problems.

I went on to create, edit, and delete recipes. No problems.

My conclusion; with the full codes in place, even starting from an empty  
database, the application is working fine.

After that, I removed the database, and the â??cookbook2â? directory, and  
re-run the tutorial from scratch.

You know what, the same old problems occurred at the point when â??Editâ?  
was introduced.

Introducing the field â??category\_idâ? and changing  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\models\category and  
C:\InstantRails-1.0\rails\_apps\cookbook2\app\models\recipe is a bit like  
introducing a field with foreign-key contrainst.

Would mySQL automatically fill up this field in the exisitng records  
when the amended codes are run?

If not, how do I fill in the blanks?  
The tutorial had been there for many months, and I am sure many people  
had taken it and there was no complaint.

So, what did I do wrong? Why me?

I would be grateful if some one would help.

After that, I went on to try â??Four Days on Railsâ? tutorial.

I was stuck because I donâ??t know how to introduce the Apache that is  
required. So I used the InstantRails 1.0 that is already installed.

When I tried to log on [http://todo/](http://todo/) I didnâ??t get the expected  
â??Congratulations â?¦â?

As I had changed the port in Apache Configuration to 4001, and Apache is  
listening to Port 80, I couldnâ??t go any further.

When I changed the Apache port back to 80, Apache couldn’t started.  
Error message said that Port 80 is used by some other process.

As you can see by now, I am new to the Apache, mySQL, and even a bit shy  
in Java Runtime, is it possible for some one to guide me through the  
initial set-up and installation of Ruby, Rails, Apache, and mySQL  
including the setting and changing of environment variables, path, lib,  
etc, so that I can get into tutorials like the top 12?

Your assistance will be appreciated.

Ling.

---

<div class="post-metadata">

**Author:** ![Ling](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c2a13f/32.png) [@Ling](https://www.ruby-forum.com/u/Ling)\
**Post date:** [May 9, 2006, 8:30pm UTC](https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985/2 "2006-05-09T20:30:13Z")

</div>

> I log into [http://localhost:3000/category/list](http://localhost:3000/category/list), chose an item, and when  
> I hit the â??Editâ? button, error message occurred.  
> Write the error message here so it would be easier to identify the  
> problem.

> After that, I went on to try â??Four Days on Railsâ? tutorial.
> 
> I was stuck because I donâ??t know how to introduce the Apache that is  
> required. So I used the InstantRails 1.0 that is already installed.
> 
> When I tried to log on [http://todo/](http://todo/) I didnâ??t get the expected  
> â??Congratulations â?¦â?

You don’t have to use Apache. I used WEBrick from InstantRails and I  
finished the â??Four Days on Railsâ? tutorial. Just remember that you can  
only use WEBrick with one app at a time. To run WEBrick, type ruby  
script\server in the todo directory. Then go to [http://localhost:3000](http://localhost:3000).

You can use phpMyAdmin (which is included in InstantRails) for creating  
your database and tables. Go to [http://localhost/mysql](http://localhost/mysql). Make sure apache  
is running. It automatically starts when you start InstantRails.

Take note that I used two servers when I was reading the tutorial.  
WEBrick is used for the ToDo app, and Apache is used for phpMyAdmin.

I also tried using Apache for my web apps and it worked, but WEBrick is  
fine and I think is even recommended.

-topher

---

<div class="post-metadata">

**Author:** ![Ling](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c2a13f/32.png) [@Ling](https://www.ruby-forum.com/u/Ling)\
**Post date:** [May 9, 2006, 8:57pm UTC](https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985/3 "2006-05-09T20:57:30Z")

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topher wrote:

> Write the error message here so it would be easier to identify the  
> problem.

Thanks.

I have un-installed and deleted all. No examples are currently  
available.

A previous error message is reproduced as follows:

That gave a url of [http://localhost:3000/recipe/edit/1](http://localhost:3000/recipe/edit/1)

Together with the error message as follows:

## RuntimeError in Recipe#edit Showing app/views/recipe/edit.rhtml where line #8 raised: Called id for nil, which would mistakenly be 4 – if you really wanted the id of nil, use object\_id Extracted source (around line #8): 5: 6:

# Edit Recipe
  
7:  
8:   
9: \<input id=“recipe\_id” name=“recipe[id]” size=“30”  
10: type=“hidden” value=“\<%= @recipe.id %\>” /\>  
11: 

**Title**  
  
RAILS\_ROOT: ./script/…/config/…  
Application Trace | Framework Trace | Full Trace  
#{RAILS\_ROOT}/app/views/recipe/edit.rhtml:8  
Request  
Parameters: {“id”=\>“1”}  
Show session dump

flash: !map:ActionController::Flash::FlashHash {}

Response  
Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”}

It appeared to me that when I made use of the full sets of codes and an  
empty database, and build up from categories to recipes, everything is  
working.

But if we introduce a new field with foreign key constraint, and modify  
the codes mid-stream, things start to break down as in the 2 tutorials I  
tried.

I might have missed out some steps, like filling in the category\_id,  
off-line, and then re-start the application.

I don’t know.

Regards,

Ling.

---

<div class="post-metadata">

**Author:** ![Ling](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c2a13f/32.png) [@Ling](https://www.ruby-forum.com/u/Ling)\
**Post date:** [May 10, 2006, 10:18pm UTC](https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985/4 "2006-05-10T22:18:37Z")

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topher wrote:

> You probably missed a few steps. Adding new columns and even foreign  
> keys on your tables shouldn’t be a problem in Rails. Just put belongs\_to  
> and has\_many and Rails will handle everything.
> 
> Here are the steps you should pay attention to.
> 
> 1. create category\_id field in the recipes table. type should be the  
> same as id in the category table
> 2. edit recipe and category models. put belongs\_to and has\_many
> 3. in recipe\_controller.rb, write the edit method
> 4. create edit.rhtml
> 
> Then test your app.
> 
> Good luck.
> 
> -topher

Thanks.

Rails4days

I was working through the â??Four days on RORâ? tutorial. I was doing fine  
from day 1 to 2.

From Day 3 onwards there were so many changes. I like the explanations.

So, I copied and pasted the codes from the PDF.

At the end of the whole process, when I ran the app there were quite a  
few errors, mostly on wrong syntax, or something in the wrong place or  
something missing. So, some codes were not copied, or the syntax were  
wrong as I pasted the amended at wrong places, or put an â??endâ? where it  
is not required.

I guess I did learn something in the process.

At the end, I got impatient.

I just copied the downloaded codes into the required directories. It  
took less than 2 minutes.

When I ran the app again, well, it was working.

😉

I thought so, anyway. I noted that the images were represented by X. I  
then realized I didnâ??t copy the image files. Since it was late, I  
switched off the PC and went to bed.

The next morning, I hopefully turned on the app. To my horrors, it  
wasn’t working.

In particular, the Webrick was not working properly.

I deleted the directory, reinstalled the InstantRails 1.0, and later  
1.3.

When I copied and pasted only a few modules, in the early part of the  
tutorial, things worked.

When I copied all the down-loaded files and pasted into the directory,  
nothing seemed to work.

Am I supposed to work through the modules step by step, and not  
encouraged to copy and paste the codes?

Can someone help to explain why the Webrick didnâ??t work?

Regards,

Ling.

---

<div class="post-metadata">

**Author:** ![Ling](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/c2a13f/32.png) [@Ling](https://www.ruby-forum.com/u/Ling)\
**Post date:** [May 10, 2006, 7:50pm UTC](https://www.ruby-forum.com/t/still-stumbled-on-first-things-in-trying-rubyonrails/59985/5 "2006-05-10T19:50:29Z")

</div>

> That gave a url of [http://localhost:3000/recipe/edit/1](http://localhost:3000/recipe/edit/1)
> 
> Together with the error message as follows:
> 
> ## RuntimeError in Recipe#edit Showing app/views/recipe/edit.rhtml where line #8 raised: Called id for nil, which would mistakenly be 4 – if you really wanted the id of nil, use object\_id Extracted source (around line #8): 5: 6:
> 
> # Edit Recipe
>   
> 7:  
> 8:   
> 9: \<input id=“recipe\_id” name=“recipe[id]” size=“30”  
> 10: type=“hidden” value=“\<%= @recipe.id %\>” /\>  
> 11: 
> 
> **Title**  
>   
> RAILS\_ROOT: ./script/…/config/…  
> Application Trace | Framework Trace | Full Trace  
> #{RAILS\_ROOT}/app/views/recipe/edit.rhtml:8  
> Request  
> Parameters: {“id”=\>“1”}  
> Show session dump
> 
> flash: !map:ActionController::Flash::FlashHash {}
> 
> Response  
> Headers: {“cookie”=\>[], “Cache-Control”=\>“no-cache”}

I think the error means that @recipe in line 8 is nil when it shouldn’t  
be. Check the edit method in recipe\_controller.rb.

> It appeared to me that when I made use of the full sets of codes and an  
> empty database, and build up from categories to recipes, everything is  
> working.
> 
> But if we introduce a new field with foreign key constraint, and modify  
> the codes mid-stream, things start to break down as in the 2 tutorials I  
> tried.
> 
> I might have missed out some steps, like filling in the category\_id,  
> off-line, and then re-start the application.
> 
> I don’t know.

You probably missed a few steps. Adding new columns and even foreign  
keys on your tables shouldn’t be a problem in Rails. Just put belongs\_to  
and has\_many and Rails will handle everything.

Here are the steps you should pay attention to.

1. create category\_id field in the recipes table. type should be the  
same as id in the category table
2. edit recipe and category models. put belongs\_to and has\_many
3. in recipe\_controller.rb, write the edit method
4. create edit.rhtml

Then test your app.

Good luck.

-topher