Hi. I need a API endpoint which is currently not present in the AOI provided by Discourse. How do I go about writing a plugin to extend the current API ? Thank you!

First, back up and say what problem you are trying to solve. It may be that you don’t need a new endpoint. Have you looked at the 'reverse engineering" topic? Next search for “plugin #howto”

As per my need, I modified the users table to add a custom attribute (Discourse custom fields was not what suited my needs). Now, I need to be able to modify that particular attribute. I need a new endpoint (just like the ‘update email’ endpoint) to modify this particular attribute from a external site.

Are you saying that you forked discourse or that you did this in a plugin? Assuming that it’s the latter, I would look for another plugin that adds an endpoint. (and hope that someone with better rails chops than I takes notice of this topic)

Yes. I did that via a plugin that I wrote. All is working fine and I am able to access the attribute via the /users/{username}.json endpoint. I do not know on how to begin writing the endpoint to modify that attribute. Do I need to add a new route and a controller for that route ? Will this do it ? Or is there something that I am missing ?

Read the poll plugin code: plugins/poll/plugin.rb main # frozen_string_literal: true # name: poll # about: Official poll plugin for Discourse # version: 1.0 # authors: Vikhyat Korrapati (vikhyat), Régis Hanol (zogstrip) # url: https://github.com/discourse/discourse/tree/main/plugins/poll register_asset "stylesheets/common/poll.scss" register_asset "stylesheets/common/poll-ui-builder.scss" register_asset "stylesheets/desktop/poll-ui-builder.scss", :desktop register_asset "stylesheets/common/poll-breakdown.scss" register_svg_icon "far-square-check" enabled_site_setting :poll_enabled module ::DiscoursePoll PLUGIN_NAME = "poll" end require_relative "lib/poll/engine" after_initialize do require_relative "app/controllers/discourse_poll/polls_controller" require_relative "app/models/poll_option" require_relative "app/models/poll_vote" require_relative "app/models/poll" require_relative "app/serializers/poll_option_serializer" require_relative "app/serializers/poll_serializer" require_relative "jobs/regular/close_poll" require_relative "lib/poll" require_relative "lib/ranked_choice" require_relative "lib/polls_updater" require_relative "lib/polls_validator" require_relative "lib/post_validator" require_relative "lib/post_extension" require_relative "lib/user_extension" Discourse::Application.routes.append { mount DiscoursePoll::Engine, at: "/polls" } allow_new_queued_post_payload_attribute("is_poll") register_post_custom_field_type(DiscoursePoll::HAS_POLLS, :boolean) topic_view_post_custom_fields_allowlister { [DiscoursePoll::HAS_POLLS] } reloadable_patch do Post.prepend(DiscoursePoll::PostExtension) User.prepend(DiscoursePoll::UserExtension) end validate(:post, :validate_polls) do |force = nil| return unless raw_changed? || force validator = DiscoursePoll::PollsValidator.new(self) return unless (polls = validator.validate_polls) return if polls.blank? && id.blank? if polls.present? validator = DiscoursePoll::PostValidator.new(self) return unless validator.validate_post end # are we updating a post? if id.present? return if polls.blank? && ::Poll.where(post: self).empty? DiscoursePoll::PollsUpdater.update(self, polls) else self.extracted_polls = polls end true end NewPostManager.add_handler(1) do |manager| post = Post.new(raw: manager.args[:raw]) if !DiscoursePoll::PollsValidator.new(post).validate_polls result = NewPostResult.new(:poll, false) post.errors.full_messages.each { |message| result.add_error(message) } result else manager.args["is_poll"] = true nil end end on(:approved_post) do |queued_post, created_post| created_post.validate_polls(true) if queued_post.payload["is_poll"] end on(:reduce_cooked) do |fragment, post| if post.nil? || post.trashed? fragment.css(".poll, [data-poll-name]").each(&:remove) else post_url = post.full_url fragment .css(".poll, [data-poll-name]") .each do |poll| html = +"" if title = poll.at_css(".poll-title") html #{I18n.t("poll.email.link_to_poll")} " poll.replace(html) end end end on(:reduce_excerpt) do |doc, options| post = options[:post] if post&.url.present? replacement = " #{I18n.t("poll.poll")} " else replacement = I18n.t("poll.poll") end doc.css("div.poll").each { |poll| poll.replace(replacement) } end on(:post_created) do |post, _opts, user| guardian = Guardian.new(user) DiscoursePoll::Poll.schedule_jobs(post) next if post.is_first_post? next if post.custom_fields[DiscoursePoll::HAS_POLLS].blank? polls = ActiveModel::ArraySerializer.new( post.polls, each_serializer: PollSerializer, root: false, scope: guardian, ).as_json post.publish_message!("/polls/#{post.topic_id}", post_id: post.id, polls: polls) end on(:post_moved) do |new_post, _original_topic_id, old_post| next if old_post.blank? || new_post.id == old_post.id ActiveRecord::Base.transaction do # Remove empty polls auto-created by PostCreator on the new post # so the originals (with votes) can be moved without a unique constraint violation. new_polls = Poll.where(post_id: new_post.id) if new_polls.exists? PollVote.where(poll_id: new_polls.select(:id)).delete_all PollOption.where(poll_id: new_polls.select(:id)).delete_all new_polls.delete_all end Poll.where(post_id: old_post.id).update_all(post_id: new_post.id) end DiscoursePoll::PollsUpdater.update_post_custom_fields(new_post) DiscoursePoll::PollsUpdater.update_post_custom_fields(old_post) end on(:merging_users) do |source_user, target_user| DB.exec(<<-SQL, source_user_id: source_user.id, target_user_id: target_user.id) DELETE FROM poll_votes WHERE user_id = :source_user_id AND EXISTS ( SELECT 1 FROM poll_votes WHERE user_id = :target_user_id AND poll_votes.poll_id = poll_votes.poll_id ); UPDATE poll_votes SET user_id = :target_user_id WHERE user_id = :source_user_id; SQL end add_to_class(:topic_view, :polls) do @polls ||= begin polls = {} post_with_polls = @post_custom_fields.each_with_object([]) do |fields, obj| obj << fields[0] if fields[1][DiscoursePoll::HAS_POLLS] end if post_with_polls.present? all_polls = Poll.includes(:poll_options).where(post_id: post_with_polls) Poll.preload!(all_polls, user_id: @user&.id) DiscoursePoll::Poll.preload_serialized_voters!(all_polls) all_polls.each do |p| polls[p.post_id] ||= [] polls[p.post_id] << p end end polls end end add_to_serializer(:current_user, :can_create_poll) do scope.user&.staff? || scope.user&.in_any_groups?(SiteSetting.poll_create_allowed_groups_map) end add_to_class(PostSerializer, :preloaded_polls) do @preloaded_polls ||= if @topic_view.present? @topic_view.polls[object.id] else Poll.includes(:poll_options).where(post: object) end end add_to_serializer(:post, :polls, include_condition: -> { preloaded_polls.present? }) do preloaded_polls.map { |p| PollSerializer.new(p, root: false, scope: scope) } end add_to_serializer( :post, :polls_votes, include_condition: -> do scope.user&.id.present? && preloaded_polls.present? && preloaded_polls.any? { |p| p.has_voted?(scope.user) } end, ) do preloaded_polls .map do |poll| if poll.ranked_choice? user_poll_votes = poll .poll_votes .where(user_id: scope.user.id) .joins(:poll_option) .pluck("poll_options.digest", "poll_votes.rank") .map { |digest, rank| { digest: digest, rank: rank } } else user_poll_votes = poll .poll_votes .where(user_id: scope.user.id) .joins(:poll_option) .pluck("poll_options.digest") end [poll.name, user_poll_votes] end .to_h end register_search_advanced_filter(/in:polls/) do |posts, match| if SiteSetting.poll_enabled posts.joins(:polls) else posts end end # Only single-choice (regular) polls are supported for anonymous voting. # Multi-choice and ranked-choice polls require accumulating selections # client-side, which is out of scope for the current anonymous flow. register_anonymous_action("vote_poll") do |user, params| options = params["options"] next if !options.is_a?(Array) || options.size != 1 DiscoursePoll::Poll.vote(user, params["post_id"], params["poll_name"], options) rescue DiscoursePoll::Error # Expected business-logic failures (poll closed, group-restricted, etc.) # — silently drop. Unexpected exceptions still bubble to AnonymousAction.consume. end end This file has been truncated. show original It has a controller and a route.

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Alfarhan_Zahedi (Alfarhan Zahedi) February 23, 2019, 10:11pm 7

Thanks. It helped.

Just in case someone else needs help in this particular topic, give this article a read - How to create a Discourse plugin – kleinfreund.de

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