java_script_agent.rb 6.3KB

    require 'date' require 'cgi' module Agents class JavaScriptAgent < Agent include FormConfigurable can_dry_run! default_schedule "never" description <<-MD The JavaScript Agent allows you to write code in JavaScript that can create and receive events. If other Agents aren't meeting your needs, try this one! You can put code in the `code` option, or put your code in a Credential and reference it from `code` with `credential:<name>` (recommended). You can implement `Agent.check` and `Agent.receive` as you see fit. The following methods will be available on Agent in the JavaScript environment: * `this.createEvent(payload)` * `this.incomingEvents()` (the returned event objects will each have a `payload` property) * `this.memory()` * `this.memory(key)` * `this.memory(keyToSet, valueToSet)` * `this.options()` * `this.options(key)` * `this.log(message)` * `this.error(message)` * `this.escapeHtml(htmlToEscape)` * `this.unescapeHtml(htmlToUnescape)` MD form_configurable :language, type: :array, values: %w[JavaScript CoffeeScript] form_configurable :code, type: :text, ace: true form_configurable :expected_receive_period_in_days form_configurable :expected_update_period_in_days def validate_options cred_name = credential_referenced_by_code if cred_name errors.add(:base, "The credential '#{cred_name}' referenced by code cannot be found") unless credential(cred_name).present? else errors.add(:base, "The 'code' option is required") unless options['code'].present? end if interpolated['language'].present? && !interpolated['language'].downcase.in?(%w[javascript coffeescript]) errors.add(:base, "The 'language' must be JavaScript or CoffeeScript") end end def working? return false if recent_error_logs? if interpolated['expected_update_period_in_days'].present? return false unless event_created_within?(interpolated['expected_update_period_in_days']) end if interpolated['expected_receive_period_in_days'].present? return false unless last_receive_at && last_receive_at > interpolated['expected_receive_period_in_days'].to_i.days.ago end true end def check log_errors do execute_js("check") end end def receive(incoming_events) log_errors do execute_js("receive", incoming_events) end end def default_options js_code = <<-JS Agent.check = function() { if (this.options('make_event')) { this.createEvent({ 'message': 'I made an event!' }); var callCount = this.memory('callCount') || 0; this.memory('callCount', callCount + 1); } }; Agent.receive = function() { var events = this.incomingEvents(); for(var i = 0; i < events.length; i++) { this.createEvent({ 'message': 'I got an event!', 'event_was': events[i].payload }); } } JS { 'code' => Utils.unindent(js_code), 'language' => 'JavaScript', 'expected_receive_period_in_days' => '2', 'expected_update_period_in_days' => '2' } end private def execute_js(js_function, incoming_events = []) js_function = js_function == "check" ? "check" : "receive" context = V8::Context.new context.eval(setup_javascript) context["doCreateEvent"] = lambda { |a, y| create_event(payload: clean_nans(JSON.parse(y))).payload.to_json } context["getIncomingEvents"] = lambda { |a| incoming_events.to_json } context["getOptions"] = lambda { |a, x| interpolated.to_json } context["doLog"] = lambda { |a, x| log x } context["doError"] = lambda { |a, x| error x } context["getMemory"] = lambda do |a, x, y| if x && y memory[x] = clean_nans(y) else memory.to_json end end context["escapeHtml"] = lambda { |a, x| CGI.escapeHTML(x) } context["unescapeHtml"] = lambda { |a, x| CGI.unescapeHTML(x) } if (options['language'] || '').downcase == 'coffeescript' context.eval(CoffeeScript.compile code) else context.eval(code) end context.eval("Agent.#{js_function}();") end def code cred = credential_referenced_by_code if cred credential(cred) || 'Agent.check = function() { this.error("Unable to find credential"); };' else interpolated['code'] end end def credential_referenced_by_code (interpolated['code'] || '').strip =~ /\Acredential:(.*)\Z/ && $1 end def setup_javascript <<-JS function Agent() {}; Agent.createEvent = function(opts) { return JSON.parse(doCreateEvent(JSON.stringify(opts))); } Agent.incomingEvents = function() { return JSON.parse(getIncomingEvents()); } Agent.memory = function(key, value) { if (typeof(key) !== "undefined" && typeof(value) !== "undefined") { getMemory(key, value); } else if (typeof(key) !== "undefined") { return JSON.parse(getMemory())[key]; } else { return JSON.parse(getMemory()); } } Agent.options = function(key) { if (typeof(key) !== "undefined") { return JSON.parse(getOptions())[key]; } else { return JSON.parse(getOptions()); } } Agent.log = function(message) { doLog(message); } Agent.error = function(message) { doError(message); } Agent.escapeHtml = function(html) { return escapeHtml(html); } Agent.unescapeHtml = function(html) { return unescapeHtml(html); } Agent.check = function(){}; Agent.receive = function(){}; JS end def log_errors begin yield rescue V8::Error => e error "JavaScript error: #{e.message}" end end def clean_nans(input) if input.is_a?(Array) input.map {|v| clean_nans(v) } elsif input.is_a?(Hash) input.inject({}) { |m, (k, v)| m[k] = clean_nans(v); m } elsif input.is_a?(Float) && input.nan? 'NaN' else input end end end end