Ruby Methods: return an usage string when insufficient arguments are given

Posted by Shyam on Stack Overflow See other posts from Stack Overflow or by Shyam
Published on 2010-04-14T14:50:41Z Indexed on 2010/04/14 14:53 UTC
Read the original article Hit count: 187

Filed under:

ruby

|

methods

|

error-handling

|

arguments

|

initialize

Hi,

After creating a serious bunch of classes, with initialize methods, loading them in IRb requires to look back at the code. However, I think it should be easy enough to return a usage message, instead of:

ArgumentError: wrong number of arguments (0 for 9)

So I prefer to return a string with the human readable arguments, by example using "puts" or just a return of a string. Now I have seen the rescue keyword inside begin-end code, but I wonder how I could catch the ArgumentError when the initialize method is called.

Thank you for your answers, feedback and comments!

© Stack Overflow or respective owner

Related posts about ruby

Setting up Rails to work with sqlserver

as seen on Stack Overflow - Search for 'Stack Overflow'
Ok I followed the steps for setting up ruby and rails on my Vista machine and I am having a problem connecting to the database. Contents of database.yml development: adapter: sqlserver database: APPS_SETUP Host: WindowsVT06\SQLEXPRESS Username: se Password: paswd Run rake db:migrate… >>> More
marshal data too short!!!

as seen on Stack Overflow - Search for 'Stack Overflow'
My application requires to keep large data objects in session. There are like 3-4 data objects each created by parsing a csv containing 150 X 20 cells having strings of 3-4 characters. My application shows this error- "marshal data too short". I tried this- Deleting the old session table. Deleting… >>> More
Sinatra and XML POST request

as seen on Stack Overflow - Search for 'Stack Overflow'
I don't know is it my mistake or no. So i have that code: <code> post '/singin/get_token' do content_type :xml puts request.body.read puts xmlRequest xmlRequest = REXML::Document.new(request.body.read) ... </code> And when i post something like that: <code> <?xml… >>> More
how to change ruby path from /usr/bin/ruby to /usr/local/bin/ruby

as seen on Stack Overflow - Search for 'Stack Overflow'
reading around the various ruby install tutorials it's required to change path from /usr/bin/ruby to /usr/local/bin/ruby but i cant seem to be able to do it. Ultimately i want to install Ruby 1.9.2, should i uninstall 1.8.7 or what? i tried to install Ruby 1.9.2 with macports, the installation seemed… >>> More
strange bundler error: tar_input.rb:49:in `initialize': not in gzip format (Zlib::GzipFile::Error) o

as seen on Stack Overflow - Search for 'Stack Overflow'
i am getting a strange bundler error when running bundle pack with bundler 0.9.12 any ideas? (see pastie for a better formatted code: http://pastie.org/881328 ) /opt/ruby-enterprise-1.8.7-2010.01/lib/ruby/site_ruby/1.8/rubygems/package/tar_input.rb:49:in `initialize': not in gzip format (Zlib::GzipFile::Error) … >>> More

Related posts about methods

how to differentiate public methods and private methods during api testing

as seen on Stack Overflow - Search for 'Stack Overflow'
is it possible to test private methods of web serive during api testing? if yes how to differentiate public methods and private methods. I am using object browser in VSTS to see the list methods available. >>> More
Action -methods vs public methods in PHP frameworks

as seen on Stack Overflow - Search for 'Stack Overflow'
There are plenty of PHP frameworks out there as many of you know, and I am interested in your thoughts on this: Zend Framework has so-called action controllers that must contain at least one action method, a method whose name ends in "Action". For example: public function indexAction() {} The word… >>> More
Use python decorators on class methods and subclass methods

as seen on Stack Overflow - Search for 'Stack Overflow'
Goal: Make it possible to decorate class methods. When a class method gets decorated, it gets stored in a dictionary so that other class methods can reference it by a string name. Motivation: I want to implement the equivalent of ASP.Net's WebMethods. I am building this on top of google app engine… >>> More
Accessing "Public" methods from "Private" methods in javascript class

as seen on Stack Overflow - Search for 'Stack Overflow'
Is there a way to call "public" javascript functions from "private" ones within a class? Check out the class below: function Class() { this.publicMethod = function() { alert("hello"); } privateMethod = function() { publicMethod(); } this.test = function() … >>> More
Parsing C#, finding methods and putting try/catch to all methods

as seen on Stack Overflow - Search for 'Stack Overflow'
I know it sounds weird but I am required to put a wrapping try catch block to every method to catch all exceptions. We have thousands of methods and I need to do it in an automated way. What do you suggest? I am planning to parse all cs files and detect methods and insert a try catch block with an… >>> More