I have variables
<% mon_has_two_sets_of_working_hours = 0 %>
<% tue_has_two_sets_of_working_hours = 0 %>
<% wed_has_two_sets_of_working_hours = 0 %>
I want to change the values of these variables dynamically.
<% days_array = ['mon', 'tue', 'wed'] %>
<% days_array.each do |day| %>
<% if condition? %>
# here i want to set %>
<% "#{day}__has_two_sets_of_working_hours" = 1 %>
end
end
The value is not getting assigned. Is there any way to assign value to variable dynamically?
I don't think there is a way to do this. There is with instance or class variables, but with local variables there is very rarely a good need.
In your case you really should have the data in a hash. Also, logic like this really does not belong in erb. You want something like:
working_hour_sets = %w[mon tue wed thu fri sat sun].inject({}) do |hash, day|
hash[day]=0;
hash
end
# puts working_hour_sets #=> {"wed"=>0, "sun"=>0, "thu"=>0, "mon"=>0, "tue"=>0, "sat"=>0, "fri"=>0}
working_hour_sets.each do |day, value|
working_hour_sets[day] = 1 if condition?
end
Now, I know this question is a bit old, but there is an easier way to do this and is using the standard Ruby send method. This is actually one of the methods that make Ruby so agile in the metaprogramming world.
This is actually a config setting I use in a Rails app:
# In a YAML
twitter:
consumer_key: 'CONSUMER-KEY'
consumer_secret: 'CONSUMER-SECRET'
oauth_token: 'OAUTH-KEY'
oauth_token_secret: 'OAUTH-SECRET'
...
# And in your file.rb
config = YAML.load_file(Rails.root.join("config", "social_keys.yml"))[Rails.env]['twitter']
Twitter.configure do |twitter|
config.each_key do |k|
twitter.send("#{k}=", config[k])
end
end
It's DRY and very easy to understand. :)
Yet another answer to this old question.
In my scenario, I wanted to count how many times a day showed up in an array of days (day_array). I didn't need to know if a day didn't show up in day_array, so I didn't initialize the days_count hash as gunn did in his answer.
Here's how I did it:
def count_days(day_array)
days_count = {}
day_array.each do |day|
days_count[day].nil? ? days_count[day] = 1 : days_count[day] = days_count[day] + 1
end
puts days_count
end
If I copy and paste the above in irb, then:
> count_days(%w[SU MO])
{"SU"=>1, "MO"=>1}
> count_days(%w[SU SU MO])
{"SU"=>2, "MO"=>1}
Basically, consistent with prior answers. But, I thought an additional example couldn't hurt.
Related
I have the following yaml file in my data dir:
---
type:
- config_setting1:
foo: bar
- config_setting2:
foo: bar
My .erb template looks like this:
conf {
<% settings = YAML.load_file('/etc/puppetlabs/code/environments/example/data/conf.yaml') -%>
<% settings['type'].each do |val| -%>
<%= val %>
<% end -%>
}
When I run puppet on my agent machine I end up with this:
conf {
{"config_setting1"=>nil, "foo"=>"bar"}
{"config_setting2"=>nil, "foo"=>"bar"}
}
My end goal is to get the output to look like this:
conf {
config_setting1 {
foo: bar
}
config_setting2 {
foo: bar
}
}
I know I have some clean up to do on my template to actually get things to output that way, but I'm more focused on the how than the end result at the moment. As you can see I'm familiar with using the ['type'] on the end of the settings to navigate through the nested hash, and I realize I could create this structure pretty easily if I hard coded it but I want to understand how to use it iteratively. I've been attempting to follow the Puppet Documentation on iterations but their examples don't work even when you copy them verbatim... which makes things a little difficult. How can I call pull out a single piece of data in a nested yaml file like I have? Either just the key or just a specific value? I tried something like:
<% settings['type'].each do |val| -%>
<%= settings['val'] %>
<% end -%>
and multiple variations of this but I couldn't find the right syntax to get what I wanted. I've also tried having something along the lines of <% settings['type'].each do |index, value| -%> but I was unable to get any results I could use out of that either. If anyone could point me in the right direction I'd appreciate it. I'm open to being told that I'm going about this entirely the wrong way as well; if there is a better way to get at this data I'm all ears.
Another question that's less important, but still irks me - in my load_file I have the absolute path... is there a way to use relative?
Amazing how typing something out will answer your own question. I realized there was a pretty easy solution. If we take my template:
conf {
<% settings = YAML.load_file('/etc/puppetlabs/code/environments/example/data/conf.yaml') -%>
<% settings['type'].each do |val| -%>
<%= val %>
<% end -%>
}
and on line three replace <% settings['type'].each do |val| -%> with <% settings.keys.each do |val| -%> I'm able to get what I'm looking for. I'd still be interested if there is a better way to do this though, either how I'm loading via yaml or otherwise.
Trying to output the contents of
node['a'] = {:b "1" :c "2"}
by doing this:
a:
<% a = node['a'] %>
b: <% a[:b] %>
c: <% a[:c] %>
<% end %>
to generate this:
a:
b: 1
c: 2
However not entirely sure the correct syntax to do this being new to ruby, chef and erb.
Okay, so let's rewind a bit. The first thing is that you generally don't want to reference node attributes directly in templates. In some cases like attributes coming from Ohai it can be okay as a shorthand, but for important data I would also pass it in via the variables property like this:
template '/etc/whatever.conf' do
source 'whatever.conf.erb'
variables a: node['a']
end
With that in place we've now expose the data as a template variable. The second piece of improving this is to let Ruby do the heavy lifting of generating YAML. We can do this using the .to_yaml method in the template:
<%= #a.to_yaml %>
That should be all you need!
I'm trying to set all the values to 0 but the 3rd line (send(x)) is giving me problems. Seems right to me, but doesn't work. x is the car and name of the columns in Power. Any tips?
<% #cars.each do |x| %>
<% #power = Power.find_by_user_id(#user) %>
<% #power.send(x) = 0 %>
<% #power.save %>
<% end %>
Assuming #cars contains column names of Power, you need to send the setter method (i.e. with an = at the end). You also need to ensure you're passing a symbol to send.
#cars.each do |x|
#power = Power.find_by_user_id(#user)
#power.send(:"#{x}=", 0)
#power.save
end
There's also not an obvious reason why you need to set or save #power in the loop, so it might be better as:
#power = Power.find_by_user_id(#user)
#cars.each do |x|
#power.send(:"#{x}=", 0)
end
#power.save
Useful additional info: I am using the decent_exposure gem so this might be the issue - correcting the code below:
expose(:get_filter_tags) do
if params[:filter_tag_names]
filter_tag_names = Array(params[:filter_tag_names].split(" "))
filter_tags = Array.new
filter_tag_names.each do |f|
t = Tag.find_by_name(f)
filter_tags << t
end
end
end
So, something funny happens when I call this in the view:
query string ?utf8=✓&filter_tag_names=test
<% get_filter_tags.each do |ft| %>
<%= ft.name %>
<% end %>
Error message: undefined method `name' for "test":String
Why is this trying to call name on a string not a Tag object? If I put the following in the view, and have jut one filter_tag_names item
def getfiltertag
Tag.find_by_name(params[:filter_tag_names])
end
#view
<%= getfiltertag.name %>
query string: ?utf8=✓&filter=test
like above then I can call name just fine, so obviously I am doing something wrong to get an array of strings instead of objects. I just don't know what. Any suggestions?
Your problem is that each returns self — so if you write filter_tag_names.each, it returns filter_tag_names. You could fix this by explicitly returning filter_tags, but more idiomatically, you could just rewrite it as:
expose(:get_filter_tags) do
if params[:filter_tag_names]
filter_tag_names = Array(params[:filter_tag_names].split(" "))
filter_tag_names.map {|f| Tag.find_by_name(f) }
end
end
Just as an aside, this method will return nil if there aren't any filter tag names. You may want to do that, or you might want to return an empty collection to avoid exceptions in the calling code.
The following view code generates a series of links with totals (as expected):
<% #jobs.group_by(&:employer_name).sort.each do |employer, jobs| %>
<%= link_to employer, jobs_path() %> <%= "(#{jobs.length})" %>
<% end %>
However, when I refactor the view's code and move the logic to a helper, the code doesn't work as expect.
view:
<%= employer_filter(#jobs_clone) %>
helper:
def employer_filter(jobs)
jobs.group_by(&:employer_name).sort.each do |employer,jobs|
link_to employer, jobs_path()
end
end
The following output is generated:
<Job:0x10342e628>#<Job:0x10342e588>#<Job:0x10342e2e0>Employer A#<Job:0x10342e1c8>Employer B#<Job:0x10342e0d8>Employer C#<Job:0x10342ded0>Employer D#
What am I not understanding? At first blush, the code seems to be equivalent.
In the first example, it is directly outputting to erb, in the second example it is returning the result of that method.
Try this:
def employer_filter(jobs)
employer_filter = ""
jobs.group_by(&:employer_name).sort.each do |employer,jobs|
employer_filter += link_to(employer, jobs_path())
end
employer_filter
end
Then call it like this in the view:
raw(employer_filter(jobs))
Also note the use of "raw". Once you move generation of a string out of the template you need to tell rails that you don't want it html escaped.
For extra credit, you could use the "inject" command instead of explicitly building the string, but I am lazy and wanted to give you what I know would work w/o testing.
This syntax worked as I hoped it would:
def employer_filter(jobs_clone)
jobs_clone.group_by(&:employer_name).sort.collect { |group,items|
link_to( group, jobs_path() ) + " (#{items.length})"
}.join(' | ').html_safe
end