Hi all,
I am learning rails by going through 3rd ed of the Rails book. In page 153, after creating the user scaffold it says: "Since this modified config/routes.rb, which is cached for performance reasons, you will need to start the server."
This is confusing me, what changed config/routes.rb? The creation of the scaffold? But this is confusion because we have created several scaffolds before for orders, line_items, etc and this was never told to us before. Why now?
Cheers,
Paulo Matos
Paulo J. Matos wrote:
I am learning rails by going through 3rd ed of the Rails book. In page 153, after creating the user scaffold it says: "Since this modified config/routes.rb, which is cached for performance reasons, you will need to start the server."
This is confusing me, what changed config/routes.rb? The creation of the scaffold? But this is confusion because we have created several scaffolds before for orders, line_items, etc and this was never told to us before. Why now?
These are two disjoint topics.
Firstly, a "scaffold generator" typically edits a few files. Use your version controller to see what it did to routes.rb. (And if you don't have a version controller, such as git or svn, install it _now_!)
Secondly, when you change a Model, Controller, or View, Rails knows to reload the source when you go to the browser and refresh (usually F5). However, Rails naturally can't extend this benefit to _all_ source. Otherwise it could end up reloading all of Ruby's standard library and everything! So routes.rb is one of the files you must bounce the server if you edit.
Next, despite scaffolds will take you a long way, you must soon stop using them, and start writing features directly. Learn that, with unit tests, and you will be reading to roll with Rails!
Phlip wrote: [...]
So routes.rb is one of the files you must bounce the server if you edit.
Unless you're using Rails 2.3, which (in dev mode) immediately incorporates changes in the routes file.
Best,
Paulo J. Matos wrote:
I am learning rails by going through 3rd ed of the Rails book. In page 153, after creating the user scaffold it says: "Since this modified config/routes.rb, which is cached for performance reasons, you will need to start the server."
This is confusing me, what changed config/routes.rb? The creation of the scaffold? But this is confusion because we have created several scaffolds before for orders, line_items, etc and this was never told to us before. Why now?
These are two disjoint topics.
Firstly, a "scaffold generator" typically edits a few files. Use your version controller to see what it did to routes.rb. (And if you don't have a version controller, such as git or svn, install it _now_!)
Definitely agree with this. I would suggest git, which has a bit of a learning curve but will be time well spent.
Secondly, when you change a Model, Controller, or View, Rails knows to reload the source when you go to the browser and refresh (usually F5). However, Rails naturally can't extend this benefit to _all_ source. Otherwise it could end up reloading all of Ruby's standard library and everything! So routes.rb is one of the files you must bounce the server if you edit.
This does not answer the OP's question as to why he got this message this time but not previously. Is it possible that the server was running this time so the message was produced, otherwise it is not produced (though I am not sure the scaffold generator would know that). Paulo, I wouldn't worry about it if I were you, just restart if necessary and carry on.
Next, despite scaffolds will take you a long way, you must soon stop using them, and start writing features directly. Learn that, with unit tests, and you will be reading to roll with Rails!
--
I disagree with that, keep using the scaffold generator to add new stuff, it is by far the easiest way of generating the files generally needed. Then use this as the base on which to build your application specific stuff. There may come a point at which it is easier to add new stuff entirely by hand but I certainly have not got there yet. Don't forget to commit your source to your version control system after running the generator so you can look back and see what you changed.
Colin
For what it's worth I am witrh Colin on this but this is covered in the foot note on page 46 of the pdf
6. If instead you see a message to the effect of No route matches "/say/hello", try stopping and restarting your server, because something you have done caused Rails to cache your configuration information before the controller was created.
The point made on the page you are talking about (p159 on the pdf) I guess is a hang over from previous vewrsions of the book that dealt with old versions of rails but it's a good lesson to learn. Always restart your server if you get unexpected results and after making a lot of changes. It takes no time to do and can save a lot of heartache trying to debug code that has no bugs!
Colin Law wrote: [...]
I disagree with that, keep using the scaffold generator to add new stuff, it is by far the easiest way of generating the files generally needed. Then use this as the base on which to build your application specific stuff.
Generally not, unless you happen to be creating apps which are very close to the scaffold.
There may come a point at which it is easier to add new stuff entirely by hand but I certainly have not got there yet.
Then either your applications are very unusual (or mine are, in the other direction) or you're relying too much on a crutch. I agree totally that the scaffold generator should not be relied on.
Don't forget to commit your source to your version control system after running the generator so you can look back and see what you changed.
Yes!
Colin
Best,
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