# Dynamic generation of routes based on db contents

**URL:** <https://www.ruby-forum.com/t/dynamic-generation-of-routes-based-on-db-contents/135094>\
**Category:** Rails\
**Created:** [April 17, 2008, 8:20pm UTC](https://www.ruby-forum.com/t/dynamic-generation-of-routes-based-on-db-contents/135094 "2008-04-17T20:20:59Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jake\_C](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/4491bb/32.png) [@Jake\_C](https://www.ruby-forum.com/u/Jake_C)\
**Post date:** [April 17, 2008, 8:20pm UTC](https://www.ruby-forum.com/t/dynamic-generation-of-routes-based-on-db-contents/135094/1 "2008-04-17T20:20:59Z")

</div>

Hello all,

I am working on a project that requires the ability to dynamically add  
one-level routes based on person name and city.

So, at any given time, someone might go to:

> **[应用宝官网-全网最新最热手机应用游戏下载](https://sj.qq.com)**
>
> 应用宝是腾讯旗下官方手机app应用商店，致力于为您提供海量、优质、安全、最新的安卓应用游戏下载！

> **[应用宝官网-全网最新最热手机应用游戏下载](https://sj.qq.com)**
>
> 应用宝是腾讯旗下官方手机app应用商店，致力于为您提供海量、优质、安全、最新的安卓应用游戏下载！

And the app needs to be smart enough to determine whether the data  
passed after / is a user name or a city name.

Each of these potential values are stored in the database, so my first  
thought was to dynamically generate it _in_ routes.rb using AR.

User.find(:all).each do |u|  
map.connect “/#{u.first\_and\_last\_name}”,  
:controller=\>UsersController, :action=\>:detail, :id=\>u.id  
end

Location.find(:all).each do | loc |  
map.connect “/#{loc.city}”, :controller=\>LocationController,  
:action=\>:detail, :id=\>loc.id  
end

This works conceptually, but my User model uses betternestedset and  
would throw an error upon server startup (acts\_as\_nested\_tree not  
defined), so I tried adding this to routes.rb:

class User \< ActiveRecord::Base;end  
class Location \< ActiveRecord::Base;end

Voila! Except for the fact that now, the rest of the app wouldn’t  
work (not exactly sure why…I presume this caused some wonkiness with  
initialization, but since I’m just re-opening and not re-defining I  
would think this would still work).

Anyway, so my next idea was to create a routing controller, simply  
route everything one deep to it, and let it do the lookups and then  
the appropriate redirect\_to. However, I’m afriad of the performance  
impacts of going this route. It should only add one db lookup and one  
redirect, but I think the redirect would likely be expensive.

I guess I forward this to the group with hopes that someone has faced  
this problem before. My questions in order would be:

1. Am I going in the completely wrong direction here?
2. Have any idea why betternestedset is throwing this area?
3. How much overhead do you think to routing controller approach would  
add.
4. Is there a better way?

Thanks for any help you can provide!

Thanks!  
Jake

---

<div class="post-metadata">

**Author:** ![Jake\_C](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/4491bb/32.png) [@Jake\_C](https://www.ruby-forum.com/u/Jake_C)\
**Post date:** [April 18, 2008, 2:33pm UTC](https://www.ruby-forum.com/t/dynamic-generation-of-routes-based-on-db-contents/135094/2 "2008-04-18T14:33:20Z")

</div>

Not sure what problem you’re having with ‘the rest of the app [not  
working]’ but I have experienced issues when loading classes at  
startup (environment.rb, initializers, etc) _in development_. The  
issue relates to the way in which classes are reloaded in dev. Short  
version is that you end up with weird ‘type mismatch’ problems even  
when you’ve got the correct class. If that’s what you’re seeing then  
you can work around it by turning on class\_caching in  
development.rb… as long as you realize you’ll have to restart your  
server for just about any dev change.

If the problem is routing (ie., none of the urls work) then it may be  
related to the placement of your code in routes.rb. Try pushing it  
toward the bottom.

Last question, though… is there a really, really compelling reason  
to use urls like this as opposed to something like  
[应用宝官网-全网最新最热手机应用游戏下载](http://www.myapp.com/users/JackCutter) and  
[应用宝官网-全网最新最热手机应用游戏下载](http://www.myapp.com/locations/LosAngeles)?

The latter are pretty easy to produce. All you have to do is override  
to\_param on the User/Location model. The nice thing is that you can  
still use the typical named routes. So, for example, the named route  
to Rome (all routes lead to Rome!):

class Location \< ARec::Base  
attr\_readonly  
before\_create :dasherize\_name

def to\_param  
self.dasherized\_name  
end

protected  
def dasherize\_name  
self.dasherized\_name = self.name.downcase.gsub(/\s+/,  
‘\_’).dasherize  
end  
end

@rome = Location.find(…)  
location\_path(@rome)

=\> …/locations/rome

And in the controller  
…  
def show  
@location = Location.find\_by\_dasherized\_name params[:id]  
end