Class: AWS::EC2::ResourceTagCollection

Inherits:
Object
  • Object
show all
Includes:
Core::Model, Enumerable
Defined in:
lib/aws/ec2/resource_tag_collection.rb

Overview

Represents the EC2 tags associated with a single resource.

Examples:

Manipulating the tags of an EC2 instance

i = ec2.instances["i-123"]
i.tags.to_h                  # => { "foo" => "bar", ... }
i.tags.clear
i.tags.stage = "production"
i.tags.stage                 # => "production"

Instance Attribute Summary

Attributes included from Core::Model

#config

Instance Method Summary collapse

Methods included from Core::Model

#client, #config_prefix, #inspect

Constructor Details

#initialize(resource, opts = {}) ⇒ ResourceTagCollection 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 31

def initialize(resource, opts = {})
  @resource = resource
  super(opts)
  @tags = TagCollection.new(:config => config).
    filter("resource-id", @resource.send(:__resource_id__)).
    filter("resource-type", @resource.tagging_resource_type)
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(m, *args) ⇒ Object

Allows setting and getting individual tags through instance methods. For example:

tags.color = "red"
tags.color         # => "red"



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 123

def method_missing(m, *args)
  if m.to_s[-1,1] == "="
    self.send(:[]=, m.to_s[0...-1], *args)
  elsif args.empty?
    self[m]
  else
    super
  end
end

Instance Method Details

#[](key) ⇒ String 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 43

def [](key)
  if cached = cached_tags
    return cached[key.to_s]
  end
  Tag.new(@resource, key, :config => config).value
rescue Resource::NotFound => e
  nil
end

#[]=(key, value) ⇒ Object Also known as: store

Changes the value of a tag.



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 86

def []=(key, value)
  if value
    @tags.create(@resource, key.to_s, :value => value)
  else
    delete(key)
  end
end

#add(key) ⇒ Object Also known as: <<

Adds a tag with a blank value.



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 98

def add(key)
  @tags.create(@resource, key.to_s)
end

#clear ⇒ Object

Removes all tags from the resource.



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 144

def clear
  client.delete_tags(:resources => [@resource.send(:__resource_id__)])
end

#delete(*keys) ⇒ Object

Deletes the tags with the given keys (which may be strings or symbols).



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 135

def delete(*keys)
  return if keys.empty?
  client.delete_tags(:resources => [@resource.send(:__resource_id__)],
                     :tags => keys.map do |key|
                       { :key => key.to_s }
                     end)
end

#each {|key, value| ... } ⇒ Object Also known as: each_pair

Yields:

  • (key, value) —

    The key/value pairs of each tag associated with the resource. If the block has an arity of 1, the key and value will be yielded in an aray.



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 151

def each(&blk)
  if cached = cached_tags
    cached.each(&blk)
    return
  end
  @tags.filtered_request(:describe_tags).tag_set.each do |tag|
    if blk.arity == 2
      yield(tag.key, tag.value)
    else
      yield([tag.key, tag.value])
    end
  end
  nil
end

#empty? ⇒ Boolean 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 53

def empty?
  if cached = cached_tags
    return cached.empty?
  end
  @tags.to_a.empty?
end

#has_key?(key) ⇒ Boolean Also known as: key?, include?, member? 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 62

def has_key?(key)
  if cached = cached_tags
    return cached.has_key?(key.to_s)
  end
  !@tags.filter("key", key.to_s).to_a.empty?
end

#has_value?(value) ⇒ Boolean Also known as: value? 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 74

def has_value?(value)
  if cached = cached_tags
    return cached.values.include?(value)
  end
  !@tags.filter("value", value.to_s).to_a.empty?
end

#set(tags) ⇒ Object Also known as: update

Sets multiple tags in a single request.



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 109

def set(tags)
  client.create_tags(:resources => [@resource.send(:__resource_id__)],
                     :tags => tags.map do |(key, value)|
                       { :key => key.to_s,
                         :value => value }
                     end)
end

#to_h ⇒ Hash 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 190

def to_h
  if cached = cached_tags
    return cached
  end
  @tags.filtered_request(:describe_tags).tag_set.inject({}) do |hash, tag|
    hash[tag.key] = tag.value
    hash
  end
end

#values_at(*keys) ⇒ Array 



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# File 'lib/aws/ec2/resource_tag_collection.rb', line 170

def values_at(*keys)
  if cached = cached_tags
    return cached.values_at(*keys.map { |k| k.to_s })
  end
  keys = keys.map { |k| k.to_s }
  tag_set = @tags.
    filter("key", *keys).
    filtered_request(:describe_tags).tag_set
  hash = tag_set.inject({}) do |hash, tag|
    hash[tag.key] = tag.value
    hash
  end
  keys.map do |key|
    hash[key]
  end
end