I have just installed the RVM and I am reading The Well-Grounded Rubyist book. In the first chapter I am supposed to try ri String#upcase to view documentation on the upcase method, however I get a message saying:
Nothing known about String#upcase
I found some posts here on SO telling me that it probably is because RDoc is not installed. However I do not understand how to fix it.
I am using Mac OSX 10.6, and latest RVM. I have only installed 1.9.2, in addition to the standard Ruby interpreter which come along with the Developer kit from Apple.
Did you generate the docs?
rvm docs generate
https://rvm.io/rubies/docs/
RDoc is installed, I'm not sure why that particular lookup does not work. Perhaps somebody else can shed some light on that.
However, if you just need to find out about how to use particular parts of the API, you can't go wrong with a google search. All of the Rdoc documentation is available online from numerous locations.
Here's String#upcase for example: http://ruby-doc.org/core/classes/String.html#M001155
It might be that docs aren't working because you're using the latest ruby version, 2.1, in which rvm has some problems. It doesn't generate docs, thus you can't retrieve the docs with ri.
**Error: **
Your ruby version 2.1.2 is not supported, only 1.8.7, 1.9.2, 1.9.3,
2.0.0
Related
My question is about the ruby-doc.org documentation, but also relates to the ri documentation lookup inside ruby.
I've already read dozens of similar questions/answers about the ri not working and giving "nothing known" messages and I've tried to follow some of that old advice. It just seems that those old answers aren't applicable to me.
One was to install the rdoc --all --ri from the ruby root directory. I tried that and it failed (unable to convert to UTF8 or something like that).
Another suggested that the rubyinstaller for windows installer just doesn't contain that info anymore and I should use the online documentation, which, when I goto http://ruby-doc.org/downloads/ I discover that the version I am using (2.4.4) does not exist.
This is odd, because the rubyinstaller site specifically says that if I'm new to Ruby(which I am), I should install 2.4.4. You'd think that if any version had good documentation, it would be that one. Instead, it seems to be missing entirely.
This all started because I am trying to learn Ruby and am watching the Lynda.com course on Ruby by Kevin Skoglund, which was recorded many versions ago and in that course he refers to the ri command from the shell, which in my version doesn't work. see below:
ruby --version
ruby 2.4.4p296 (2018-03-28 revision 63013) [x64-mingw32]
ri --version
ri.cmd 5.0.0
ri String
Nothing known about String
Now, if it's not available within ruby using ri, and I have to use online documentation, AND it's missing for my version, which happens to be the version recommended for new users, … you see my frustration.
Here's what I really want...
1. I want to use ri and have it work.
2. If that's just not possible, I'd like to know where the documentation for my version is online, because it's not where it's supposed to be.
Any help is appreciated. If it involves installing anything, letting me know HOW to do that is also appreciated. As I mentioned, I'm new.
Since you are using the RubyInstaller, I will assume that you are on Windows.
I will open this by saying that I am not 100% on this, but I am pretty condfident in this answer.
The "Use 2.4, not 2.5" was due to errors with Ruby Gem when Ruby 2.5
was first released, as I happen to be on a Windows machine installing
Ruby at that exact time, and that was the reasoning at that point not
to use the newest 2.5 version.
The above mentioned reason has since been corrected.
Realistically, if you are beginner, as long as you using documentation that is close to your version (2.0+ - 2.4-ish), it will be fine. Now obviously, and I shouldn't have to provide this disclaimer, though I will so to avoid the inevitable down-votes if I don't, this is not 100% perfect solution and there will be very small differences. As a beginner, the likelihood of you encountering any of these differences are extremely low, low enough not to even worry about. There are missing and poorly documented sections of every language, and Ruby is no exception. Typically these are less used classes (though Ruby Fiddle is an exception that I hate how poorly documented it is), and will have no effect on your learning process as you learn the fundamentals and core of the language.
To my recollection, the "core" is rather well documented, and so long as you use documentation from 2.0+ (the closer to 2.4 the better), you should be completely fine, and it is exactly the same. The "standard library" may be slightly more hit or miss, and your mileage may vary a little more, yet still nothing too extreme.
So, to address the second part of your question, do not worry too hard about finding the EXACT version of documentation you are using. It may not even exist online, though the installer should have provided a CHM help file (there will be shortcut for it with the shortcuts for Ruby, IRB, etc.
As for "why" ri is not working, I am not 100% sure yet again. I am on ArchLinux, and RDoc doesn't even built. Honestly, RDoc is being left by the wayside for newer (and IMO better) document engine, namely YARD. A possible solution that I do, and prefer, is to install the YARD gem right after I install Ruby:
gem install yard
And then set YARD to generate my documentation with this in CMD:
yard config --gem-install-yri
If you decide to take this route, much more can be learned about it here.
The benefit with it is that it also supports RDoc and is backwards compatible.
I'm using rvm on Ubuntu 12 to manage ruby versions/gemsets. I am testing various projects and some gems won't work with certain versions of Ruby or with each other. Is it possible to find which version of ruby an app was written for, so I can set my rvm to use that version and get the right gems when I run bundle install?
You can lookup the gems on rubygems.org. They are supposed to list what version of ruby they are compatible with, but that may not always be kept up to date.
If that doesn't narrow it down, you can check the gem's CHANGELOG file on github.
In the end, you may have to just try a few. There's only a handful of versions in common use, so it's not like you have to try then all.
in my experience ruby 1.9.3 is most widely supported at the time of this writing. Ruby 2.0 and 2.1 would also be good to try. 1.8.7 is pretty old and will likely give you a good bit of trouble, but it was the standard for a long time.
Ri seems to be giving results for Rails. Something is not right.
Can anyone help me get useful results from ri. I have an otherwise clean and working up-to-date installation of Ruby (1.9.3) and Rails (3.2.3).
For example if do ri Range I get this.
Range < Object
(from gem activesupport-3.2.3)
Constants:
RANGE_FORMATS
[not documented]
Instance methods:
include_with_range?
overlaps?
step_with_blockless
to_default_s
to_formatted_s
to_s
#Casper pointed me to another SO answer
which gave me the information I needed to understand what was happening with ri.
1. ri is not installed automatically since it adds so much size to the install; instead .chm style help files are installed. But these seem to be the same as the help available on line via RubyDocs.
2. I think rails may have installed some ri docs, so that when I use ri I do get results for certain queries like the one I listed in my example above.
I'm trying to prettify my rdoc documentation, using version 3.5.3. I'm not a fan of the built-in darkfish theme, so I tried to find a way to replace it with the one used by the official Rails API documentation at http://api.rubyonrails.org/, but I've had no luck finding it in any readily available form. I've searched all over github, among other things.
What I've found so far is
https://github.com/mislav/hanna
which might be slightly out of date, and it's fork
https://github.com/rdoc/hanna-nouveau
Both are nice, but not quite what I want. So before I start fiddling with those templates, does anyone know if the template used by the Rails API docs is available as a gem somewhere?
Thanks!
I know this is very late, but it looks like the new version of Rails uses something called sdoc, which enhances the output with JavaScript searching, and is a little cleaner IMO. Doing a simple "gem install sdoc" will get what you need, then just use rdoc.options << '-f' << 'sdoc'.
The github project appears to be at https://github.com/voloko/sdoc/
By the way, thanks for the question! Without the initial answer posted, I'd have never found where to look, and been stuck with that horrible darkfish theme for my own projects!
This looks like it. Ignore the instructions that say to do a gem install horo --pre -- that'll actually give you an older beta version. Just do gem install horo and you'll get the current 1.0.3 version (Edit: I sent a pull request to update the instructions, which has already been accepted).
https://github.com/tenderlove/horo
By the way, I found this by looking at the Rails source code and viewing the Rakefile to see the RDoc options. Specifically, line 67 shows rdoc.options << '-f' << 'horo'.
I have a ruby gem I created and installed and want to be able to use it in a Shoes app. As expected, Shoes reports it cannot find the gem, understandably since the gem is only installed for the standard ruby distribution. Can help pointing towards documentation explaining how to get Shoes to find this gem would be most appreciated.
Thanks.
Unless things have changed since _why left, this is not possible. Shoes is a separate Ruby installation and therefore needs its own gems.
To install a gem, you can do something like this at the beginning of your Shoes app:
Shoes.setup do
gem 'json'
end
Edit: there's also this previous SO thread:
Using Ruby libraries and gems with a Shoes app
U can think Shoes as a ruby-distro, like jruby or other rubies, it maintains its own gems.
therefore you will need to install it via shoes way like Michael Kohl said