I have a markdown file which should have a YAML front matter in it (a Jekyll post file). I read the YAML part of the file with
yaml = YAML.load_file(filename)
Now when the file contains the YAML part no problem, otherwise exits with an error.
My question is: how do you handle this error in ruby such that the program notifies me of the missing header but still continues to execute the rest of the code?
This might work.
begin
yaml = YAML.load_file(filename)
rescue
#log or notification code here
end
Related
I have a 30MB XML file that contains some gibberish in the beginning, and so typically I have to remove that in order for Nokogiri to be able to parse the XML document properly.
Here's what I currently have:
contents = File.open(file_path).read
if contents[0..123].include? 'authenticate_response'
fixed_contents = File.open(file_path).read[123..-1]
File.open(file_path, 'w') { |f| f.write(fixed_contents) }
end
However, this actually causes the ruby script to open up the large XML file twice. Once to read the first 123 characters, and another time to read everything but the first 123 characters.
To solve the first issue, I was able to accomplish this:
contents = File.open(file_path).read(123)
However, now I need to remove these characters from the file without reading the entire file. How can I "trim" the beginning of this file without having to open the entire thing in memory?
You can open the file once, then read and check the "garbage" and finally pass the opened file directly to nokogiri for parsing. That way, you only need read the file once and don't need to write it at all.
File.open(file_path) do |xml_file|
if xml_file.read(123).include? 'authenticate_response'
# header found, nothing to do
else
# no header found. We rewind and let nokogiri parse the whole file
xml_file.rewind
end
xml = Nokogiri::XML.parse(xml_file)
# Now to whatever you want with the parsed XML document
end
Please refer to the documentation of IO#read, IO#rewind and Nokigiri::XML::Document.parse for details about those methods.
This is the contents of my .rspec_parallel file. I am using parallel_tests gem to run tests in multiple browser instances. To my knowledge, the gem uses the same formatter options available in RSpec.
--format html --out results<%= ENV['TEST_ENV_NUMBER'] %>.html
This works fantastic and I'm able to get the HTML output I normally see from RSpec. However, all of the 'puts' messages and basic standard output is logged to my console window, and not to the HTML files.
How can I get this output into each individual HTML file that I have set up?
puts will output to $stdout where as output is actually an instance variable of the RSpec::Core::Formatters::BaseFormatter class. output is defaulted to $stdout but when you pass in a string it determines that it should create a new StringIO and then output this to the given file name. Thus puts will not append to the #output variable.
You could do something ugly like create a runner file like
File.open('some_file_name.html','w+') do |file|
file << `rspec spec --format html`
end
Then this file will have the output from $stdoutbut your puts code will not be html formatted in this case. Other than that you could try building your own Custom Formatter but it will probably take quite a bit of source searching to make sure you can capture everything appropriately.
That being said it does seem the reporter was exposed for adding custom messages but I am uncertain of how to use this appropriately See Pull Request 1866
Seems it would be something like
it "has a name" do |ex|
ex.reporter.message("Custom Message Here")
#actual test
end
but the html formatter seems to ignore this. I can see the output in $stdout but not in the html file itself.
Best of luck.
In order to have only a single point of configuration for my app I need to make a YAML config file that is also valid ruby code. I.e. a mixed syntax file that can be parsed as YAML and parsed as ruby.
My application is a suite of processes managed by the god gem. I want to load a new group of maintained processes (watches) for each new configuration file.
God allows loading a new app.god (ruby) file with new watches defined, but I don't want an app.god and app.yml, just one file. Simplest might be to just have the app.god file and include the configuration within that, but I preferred the idea of a yml file that was also valid ruby code.
#I found this that might be helpful:
#This is a valid ruby and a valid YAML file
#Comments are the same in YAML and ruby
true ?true:
- <<YAML.to_i
# At this point in ruby it is the contents of a here doc (that will be
# converted to an integer and negated if true happens not to be true)
# In YAML it is a hash with the first entry having key "true ?true"
# representing a list containing the string "- <<YAML.to_i"
# If your YAML object should be a list not a hash you could remove the first line
any_valid_yaml: from here
a_list:
- or
- anything
- really
#Then mark the end of the YAML document with
---
#And YAML is done and ignores anything from here on
#Next terminate the ruby here document
YAML
#Now we're in ruby world
#this = "pure ruby"
def anything(ruby)
"here"
end
I am using sinatra,ruby and MongoDB to export a CSV file from the MongoDB. I am able to create the CSV file and export it.
I delete the file after exporting it.
But it gets deleted only after I exit sinatra.
Can anybody explain why is this?
Suppose a file abc****.csv is created.
I am deleting this file using
file_path = '/home/Test_app';
file = Tempfile.new([##uname,'.csv'],file_path);
file_name = file.path();
puts file_name # gives /home/Test_app/xyz****.csv
send_file(file_name, :disposition => 'attachment', :filename =>File.basename(file_name));
File.delete(file_name);
File.unlink(file_name);
But it gets deleted only after I exit sinatra server. Can anyone explain please?
Your never call file.close, meaning the file will be kept open and therefore not deleted until your application exits.
Try following the suggestion given in the Tempfile documentation:
file = Tempfile.new('foo')
begin
...do something with file...
ensure
file.close
file.unlink # deletes the temp file
end
This will make sure the file is properly closed and deleted even in the event of exceptions being raised in the code between begin and ensure.
Perhaps this is a large file; since the HTTP connection does not close until the streaming is complete, the code after send_file is not getting executed. That might be a valid reason. Have you checked if the entire file is being downloaded to the client? If that is not the case, try it out with a smaller file. I'm assuming you've implemented (but haven't written it here) the code for the data getting written into the file_name from MongoDB.
I am trying to write a ruby fcgi script which compresses files in a directory on the fly and sends the output blockwise as an http response. It is very important that this compression is done as a stream operation, otherwise the client will get a timeout for huge directories.
I have the following code:
d="/tmp/delivery/"
# send zip header
header(MimeTypes::ZIP)
# pseudocode from here on
IO.open(d) { |fh|
block=fh.readblock(1024)
#send zipped block as http response
print zip_it(block)
}
How do I achieve what I've written as pseudo-ruby in the above listing?
Tokland's idea of using the external zip command works pretty well. Here's a quick snippet that should work with Ruby 1.9 on Linux or similar environments. It uses an array parameter to popen() to avoid any shell quoting issues and sysread/syswrite to avoid buffering. You could display a status message in the empty rescue block if you like -- or you could use read and write, though I haven't tested those.
#! usr/bin/env ruby
d = '/tmp/delivery'
output = $stdout
IO.popen(['/usr/bin/zip', '-', d]) do |zip_output|
begin
while buf = zip_output.sysread(1024)
output.syswrite(buf)
end
rescue EOFError
end
end
AFAYK Zip format is not streamable, at end of compression it writes something in the file header.
gz or tar.gz is better option.
solved:
https://github.com/fringd/zipline.git