add backlinks

lib/memex/contexts.ex

@@ -88,6 +88,42 @@ defmodule Memex.Contexts do
     )
   end
 
+  @doc """
+  Returns the list of contexts that link to a particular slug.
+
+  ## Examples
+
+      iex> backlink(%User{id: 123})
+      [%Context{}, ...]
+
+      iex> backlink("[other-context]", %User{id: 123})
+      [%Context{content: "[other-context]"}, ...]
+
+  """
+  @spec backlink(String.t(), User.t()) :: [Context.t()]
+  def backlink(link, %{id: user_id}) when user_id |> is_binary() do
+    link = link |> String.replace("[", "\\[") |> String.replace("]", "\\]")
+    link_regex = "(^|[^\[])#{link}($|[^\]])"
+
+    Repo.all(
+      from c in Context,
+        where: fragment("? ~ ?", c.content, ^link_regex),
+        order_by: c.slug
+    )
+  end
+
+  def backlink(link, _invalid_user) do
+    link = link |> String.replace("[", "\\[") |> String.replace("]", "\\]")
+    link_regex = "(^|[^\[])#{link}($|[^\]])"
+
+    Repo.all(
+      from c in Context,
+        where: fragment("? ~ ?", c.content, ^link_regex),
+        where: c.visibility == :public,
+        order_by: c.slug
+    )
+  end
+
   @doc """
   Gets a single context.
 

lib/memex/notes.ex

@@ -86,6 +86,42 @@ defmodule Memex.Notes do
     )
   end
 
+  @doc """
+  Returns the list of notes that link to a particular slug.
+
+  ## Examples
+
+      iex> backlink(%User{id: 123})
+      [%Note{}, ...]
+
+      iex> backlink("[other-note]", %User{id: 123})
+      [%Note{content: "[other-note]"}, ...]
+
+  """
+  @spec backlink(String.t(), User.t()) :: [Note.t()]
+  def backlink(link, %{id: user_id}) when user_id |> is_binary() do
+    link = link |> String.replace("[", "\\[") |> String.replace("]", "\\]")
+    link_regex = "(^|[^\[])#{link}($|[^\]])"
+
+    Repo.all(
+      from n in Note,
+        where: fragment("? ~ ?", n.content, ^link_regex),
+        order_by: n.slug
+    )
+  end
+
+  def backlink(link, _invalid_user) do
+    link = link |> String.replace("[", "\\[") |> String.replace("]", "\\]")
+    link_regex = "(^|[^\[])#{link}($|[^\]])"
+
+    Repo.all(
+      from n in Note,
+        where: fragment("? ~ ?", n.content, ^link_regex),
+        where: n.visibility == :public,
+        order_by: n.slug
+    )
+  end
+
   @doc """
   Gets a single note.
 

lib/memex/pipelines.ex

@@ -142,6 +142,50 @@ defmodule Memex.Pipelines do
     )
   end
 
+  @doc """
+  Returns the list of pipelines that link to a particular slug.
+
+  ## Examples
+
+      iex> backlink(%User{id: 123})
+      [%Pipeline{}, ...]
+
+      iex> backlink("[other-pipeline]", %User{id: 123})
+      [%Pipeline{description: "[other-pipeline]"}, ...]
+
+  """
+  @spec backlink(String.t(), User.t()) :: [Pipeline.t()]
+  def backlink(link, %{id: user_id}) when user_id |> is_binary() do
+    link = link |> String.replace("[", "\\[") |> String.replace("]", "\\]")
+    link_regex = "(^|[^\[])#{link}($|[^\]])"
+
+    Repo.all(
+      from p in Pipeline,
+        left_join: s in assoc(p, :steps),
+        where:
+          fragment("? ~ ?", p.description, ^link_regex) or
+            fragment("? ~ ?", s.content, ^link_regex),
+        distinct: true,
+        order_by: p.slug
+    )
+  end
+
+  def backlink(link, _invalid_user) do
+    link = link |> String.replace("[", "\\[") |> String.replace("]", "\\]")
+    link_regex = "(^|[^\[])#{link}($|[^\]])"
+
+    Repo.all(
+      from p in Pipeline,
+        left_join: s in assoc(p, :steps),
+        where:
+          fragment("? ~ ?", p.description, ^link_regex) or
+            fragment("? ~ ?", s.content, ^link_regex),
+        where: p.visibility == :public,
+        distinct: true,
+        order_by: p.slug
+    )
+  end
+
   @doc """
   Creates a pipeline.
 

lib/memex_web/live/context_live/show.ex

@@ -1,6 +1,6 @@
 defmodule MemexWeb.ContextLive.Show do
   use MemexWeb, :live_view
-  alias Memex.Contexts
+  alias Memex.{Contexts, Pipelines}
 
   @impl true
   def mount(_params, _session, socket) do
@@ -23,7 +23,9 @@ defmodule MemexWeb.ContextLive.Show do
       socket
       |> assign(
         context: context,
-        page_title: page_title(live_action, context)
+        page_title: page_title(live_action, context),
+        context_backlinks: Contexts.backlink("[#{context.slug}]", current_user),
+        pipeline_backlinks: Pipelines.backlink("[[#{context.slug}]]", current_user)
       )
 
     {:noreply, socket}

lib/memex_web/live/context_live/show.html.heex

@@ -11,6 +11,27 @@
 
   <.context_content context={@context} />
 
+  <div
+    :if={@context_backlinks ++ @pipeline_backlinks != []}
+    class="flex flex-wrap justify-end items-center self-end"
+  >
+    <p><%= gettext("Backlinked by:") %></p>
+    <.link
+      :for={backlink <- @context_backlinks}
+      class="m-1 hover:underline"
+      patch={~p"/context/#{backlink}"}
+    >
+      <%= gettext("[%{slug}]", slug: backlink.slug) %>
+    </.link>
+    <.link
+      :for={backlink <- @pipeline_backlinks}
+      class="m-1 hover:underline"
+      patch={~p"/pipeline/#{backlink}"}
+    >
+      <%= gettext("[[%{slug}]]", slug: backlink.slug) %>
+    </.link>
+  </div>
+
   <p class="self-end">
     <%= gettext("Visibility: %{visibility}", visibility: @context.visibility) %>
   </p>

lib/memex_web/live/home_live.html.heex

@@ -1,5 +1,5 @@
-<div class="mx-auto flex flex-col justify-center items-stretch space-y-4 max-w-lg">
-  <h1 class="title text-primary-400 text-xl">
+<div class="flex flex-col justify-center items-stretch mx-auto space-y-4 max-w-lg">
+  <h1 class="text-xl title text-primary-400">
     <%= gettext("memEx") %>
   </h1>
 
@@ -31,7 +31,7 @@
       </p>
     </li>
 
-    <li class="flex flex-col justify-center items-center text-right space-y-2">
+    <li class="flex flex-col justify-center items-center space-y-2 text-right">
       <.link navigate={~p"/faq"} class="btn btn-primary">
         <%= gettext("read more on how to use memEx") %>
       </.link>
@@ -41,7 +41,7 @@
   <hr class="hr" />
 
   <ul class="flex flex-col space-y-4">
-    <h2 class="title text-primary-400 text-lg">
+    <h2 class="text-lg title text-primary-400">
       <%= gettext("features") %>
     </h2>
 
@@ -71,12 +71,21 @@
         <%= gettext("accessible from any internet-capable device") %>
       </p>
     </li>
+
+    <li class="flex flex-col justify-center items-center space-y-2">
+      <b class="whitespace-nowrap">
+        <%= gettext("backlinks:") %>
+      </b>
+      <p>
+        <%= gettext("view referencing items from the referenced item") %>
+      </p>
+    </li>
   </ul>
 
   <hr class="hr" />
 
   <ul class="flex flex-col justify-center space-y-4">
-    <h2 class="title text-primary-400 text-lg">
+    <h2 class="text-lg title text-primary-400">
       <%= gettext("instance information") %>
     </h2>
 
@@ -124,7 +133,7 @@
   <hr class="hr" />
 
   <ul class="flex flex-col space-y-2">
-    <h2 class="title text-primary-400 text-lg">
+    <h2 class="text-lg title text-primary-400">
       <%= gettext("get involved") %>
     </h2>
 

lib/memex_web/live/note_live/show.ex

@@ -1,6 +1,6 @@
 defmodule MemexWeb.NoteLive.Show do
   use MemexWeb, :live_view
-  alias Memex.Notes
+  alias Memex.{Contexts, Notes, Pipelines}
 
   @impl true
   def mount(_params, _session, socket) do
@@ -22,8 +22,11 @@ defmodule MemexWeb.NoteLive.Show do
     socket =
       socket
       |> assign(
+        context_backlinks: Contexts.backlink("[[#{note.slug}]]", current_user),
+        note_backlinks: Notes.backlink("[#{note.slug}]", current_user),
         note: note,
-        page_title: page_title(live_action, note)
+        page_title: page_title(live_action, note),
+        pipeline_backlinks: Pipelines.backlink("[[[#{note.slug}]]]", current_user)
       )
 
     {:noreply, socket}

lib/memex_web/live/note_live/show.html.heex

@@ -11,6 +11,34 @@
 
   <.note_content note={@note} />
 
+  <div
+    :if={@note_backlinks ++ @context_backlinks ++ @pipeline_backlinks != []}
+    class="flex flex-wrap justify-end items-center self-end"
+  >
+    <p><%= gettext("Backlinked by:") %></p>
+    <.link
+      :for={backlink <- @note_backlinks}
+      class="m-1 hover:underline"
+      patch={~p"/note/#{backlink}"}
+    >
+      <%= gettext("[%{slug}]", slug: backlink.slug) %>
+    </.link>
+    <.link
+      :for={backlink <- @context_backlinks}
+      class="m-1 hover:underline"
+      patch={~p"/context/#{backlink}"}
+    >
+      <%= gettext("[[%{slug}]]", slug: backlink.slug) %>
+    </.link>
+    <.link
+      :for={backlink <- @pipeline_backlinks}
+      class="m-1 hover:underline"
+      patch={~p"/pipeline/#{backlink}"}
+    >
+      <%= gettext("[[[%{slug}]]]", slug: backlink.slug) %>
+    </.link>
+  </div>
+
   <p class="self-end">
     <%= gettext("Visibility: %{visibility}", visibility: @note.visibility) %>
   </p>

lib/memex_web/live/pipeline_live/show.ex

@@ -23,6 +23,7 @@ defmodule MemexWeb.PipelineLive.Show do
       socket
       |> assign(
         page_title: page_title(live_action, pipeline),
+        pipeline_backlinks: Pipelines.backlink("[#{pipeline.slug}]", current_user),
         pipeline: pipeline,
         steps: pipeline |> Steps.list_steps(current_user)
       )

lib/memex_web/live/pipeline_live/show.html.heex

@@ -11,6 +11,17 @@
 
   <.pipeline_content pipeline={@pipeline} />
 
+  <div :if={@pipeline_backlinks != []} class="flex flex-wrap justify-end items-center self-end">
+    <p><%= gettext("Backlinked by:") %></p>
+    <.link
+      :for={backlink <- @pipeline_backlinks}
+      class="m-1 hover:underline"
+      patch={~p"/pipeline/#{backlink}"}
+    >
+      <%= gettext("[%{slug}]", slug: backlink.slug) %>
+    </.link>
+  </div>
+
   <p class="self-end">
     <%= gettext("Visibility: %{visibility}", visibility: @pipeline.visibility) %>
   </p>