Class: Homebrew::Livecheck::Strategy::Json

Inherits:
Object
  • Object
show all
Extended by:
Homebrew::Livecheck::Strategic
Defined in:
livecheck/strategy/json.rb

Overview

The Json strategy fetches content at a URL, parses it as JSON and provides the parsed data to a strategy block. If a regex is present in the livecheck block, it should be passed as the second argument to the strategy block.

This is a generic strategy that doesn't contain any logic for finding versions, as the structure of JSON data varies. Instead, a strategy block must be used to extract version information from the JSON data.

This strategy is not applied automatically and it is necessary to use strategy :json in a livecheck block (in conjunction with a strategy block) to use it.

This strategy's Json.find_versions method can be used in other strategies that work with JSON content, so it should only be necessary to write the version-finding logic that works with the parsed JSON data.

Constant Summary collapse

NICE_NAME = 
"JSON"
PRIORITY =

This constant is part of a private API. This constant may only be used in the Homebrew/brew repository. Third parties should avoid using this constant if possible, as it may be removed or changed without warning.

A priority of zero causes livecheck to skip the strategy. We do this for Homebrew::Livecheck::Strategy::Json so we can selectively apply it only when a strategy block is provided in a livecheck block.

0
URL_MATCH_REGEX =

This constant is part of a private API. This constant may only be used in the Homebrew/brew repository. Third parties should avoid using this constant if possible, as it may be removed or changed without warning.

The Regexp used to determine if the strategy applies to the URL.

%r{^https?://}i

Class Method Summary collapse

Methods included from Homebrew::Livecheck::Strategic

find_versions, match?

Class Method Details

.find_versions(url:, regex: nil, provided_content: nil, options: Options.new, &block) ⇒ Hash{Symbol => T.anything}

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Checks the JSON content at the URL for versions, using the provided strategy block to extract version information.

Parameters:

  • url (String) —

    the URL of the content to check

  • regex (Regexp, nil) (defaults to: nil) —

    a regex used for matching versions

  • provided_content (String, nil) (defaults to: nil) —

    page content to use in place of fetching via Strategy#page_content

  • options (Options) (defaults to: Options.new) —

    options to modify behavior

  • block (Proc, nil)

Returns:

Raises:

  • (ArgumentError) 


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# File 'livecheck/strategy/json.rb', line 112

def self.find_versions(url:, regex: nil, provided_content: nil, options: Options.new, &block)
  raise ArgumentError, "#{Utils.demodulize(name)} requires a `strategy` block" unless block_given?

  match_data = { matches: {}, regex:, url: }
  return match_data if url.blank?

  content = if provided_content.is_a?(String)
    match_data[:cached] = true
    provided_content
  else
    match_data.merge!(Strategy.page_content(url, options:))
    match_data[:content]
  end
  return match_data if content.blank?

  versions_from_content(content, regex, &block).each do |match_text|
    match_data[:matches][match_text] = Version.new(match_text)
  end

  match_data
end

.match?(url) ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Whether the strategy can be applied to the provided URL. Homebrew::Livecheck::Strategy::Json will technically match any HTTP URL but is only usable with a livecheck block containing a strategy block.

Parameters:

  • url (String) —

    the URL to match against

Returns:

  • (Boolean) 


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# File 'livecheck/strategy/json.rb', line 47

def self.match?(url)
  URL_MATCH_REGEX.match?(url)
end

.parse_json(content) ⇒ T.untyped

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parses JSON text and returns the parsed data.

Parameters:

  • content (String) —

    the JSON text to parse

Returns:

  • (T.untyped) 


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# File 'livecheck/strategy/json.rb', line 54

def self.parse_json(content)
  require "json"

  begin
    JSON.parse(content)
  rescue JSON::ParserError
    raise "Content could not be parsed as JSON."
  end
end

.versions_from_content(content, regex = nil, &block) ⇒ Array<String>

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parses JSON text and identifies versions using a strategy block. If the block has two parameters, the parsed JSON data will be used as the first argument and the regex (if any) will be the second. Otherwise, only the parsed JSON data will be passed to the block.

Parameters:

  • content (String) —

    the JSON text to parse and check

  • regex (Regexp, nil) (defaults to: nil) —

    a regex used for matching versions in the content

  • block (Proc, nil)

Returns:



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# File 'livecheck/strategy/json.rb', line 80

def self.versions_from_content(content, regex = nil, &block)
  return [] if content.blank? || !block_given?

  json = parse_json(content)
  return [] if json.blank?

  block_return_value = if block.arity == 2
    yield(json, regex)
  else
    yield(json)
  end
  Strategy.handle_block_return(block_return_value)
end