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

Returns a new instance of 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

Returns The value of the tag with the given key, or nil if no such tag exists.

Parameters:

  • key (String or Symbol) —

    The key of the tag to return.

Returns:

  • (String) —

    The value of the tag with the given key, or nil if no such tag exists.



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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.

Parameters:

  • key (String or Symbol) —

    The key of the tag to set.

  • value (String) —

    The new value. If this is nil, the tag will be deleted.



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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.

Parameters:

  • key (String or Symbol) —

    The key of the new tag.



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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

Returns True if the resource has no tags.

Returns:

  • (Boolean) —

    True if the resource has no tags.



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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?

Returns True if the resource has a tag for the given key.

Parameters:

  • key (String or Symbol) —

    The key of the tag to check.

Returns:

  • (Boolean) —

    True if the resource has a tag for the given key.



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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?

Returns True if the resource has a tag with the given value.

Parameters:

  • value (String or Symbol) —

    The value to check.

Returns:

  • (Boolean) —

    True if the resource has a tag with the given 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.

Parameters:

  • tags (Hash) —

    The tags to set. The keys of the hash may be strings or symbols, and the values must be strings. Note that there is no way to both set and delete tags simultaneously.



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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

Returns The current tags as a hash, where the keys are the tag keys as strings and the values are the tag values as strings.

Returns:

  • (Hash) —

    The current tags as a hash, where the keys are the tag keys as strings and the values are the tag values as strings.



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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

Returns An array of the tag values associated with the given keys. An entry for a key that has no value (i.e. there is no such tag) will be nil.

Returns:

  • (Array) —

    An array of the tag values associated with the given keys. An entry for a key that has no value (i.e. there is no such tag) will be nil.



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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