Question

Is it possible to get the Unique values of a Hash? Lets say I have a hash which one of the keys is “name” Name can come up a couple dozen times, but it will only have lets say 10 variations of itself all unique. What I want to do is be able to take those 10 unique names and build a view based off of them. But in order to roll the view out properly I would need to know those unique names. Im thinking I have to build an array, or another hash or something of the unique names. So I can go over that array with “each” then for each unique if the original hash has a match apply it to that section or block on the view. Hopefully this makes sense to someone. Who can help me out.

val = {
    :status => "successful",
    :service_list => [
        {
            :service_name => "oozie",
            :status => "RUNNING",
            :status_message => "Running Master Service",
            :host => "1"
        },
        {
            :service_name => "single-namenode",
            :status => "RUNNING",
            :status_message => "Running Service",
            :host => "1"
        },
        {
            :service_name => "single-database",
            :status => "RUNNING",
            :status_message => "Running Service",
            :host => "1"
        }
]}

truncated version of the hash I am working with.

Answer 1

Not sure if it is the right answer, but the list of unique service names can be obtained like this:

val[:service_list].map { |service| service[:service_name] }.uniq
# ["oozie", "single-namenode", "single-database"]

Update:

Iterating over the hash of services grouped by service_name is a little easier, here’s an example:

In the action of your controller:

@services =  val[:service_list].group_by { |service| service[:service_name] }

# {
#    "oozie" => [ { ... }, { ... } ],
#    "single-namenode" => [ { ... }, { ... } ],
#    "single-database" => [ { ... }, { ... } ]
# }

In your view

<% for name, services in @services %>
    All services with name <%= name %>
    <% for service in services %>
        <%= service[:host] %>, Status: <%= service[:status] %>
    <% end %>
<% end %>

Hope that helps