From 828871dfb119098202eb9312a92fb1334b3016ff Mon Sep 17 00:00:00 2001
From: Chris Amico <eyeseast@gmail.com>
Date: Thu, 28 Mar 2024 15:32:13 -0400
Subject: [PATCH] Basic infinite scroll for search results

---
 src/lib/api/documents.ts                      | 22 +++++--
 src/lib/api/types.d.ts                        |  9 ++-
 src/lib/components/Search.svelte              | 12 ++--
 .../components/documents/ResultsList.svelte   | 60 +++++++++++++----
 .../stories/ResultsList.stories.svelte        | 18 ++----
 src/routes/app/+page.svelte                   | 64 ++-----------------
 src/routes/app/+page.ts                       | 25 +++++++-
 src/style/kit.css                             | 18 ++++++
 8 files changed, 130 insertions(+), 98 deletions(-)

diff --git a/src/lib/api/documents.ts b/src/lib/api/documents.ts
index 3dfb4baaa..b6b88f99f 100644
--- a/src/lib/api/documents.ts
+++ b/src/lib/api/documents.ts
@@ -1,7 +1,7 @@
 /** API helpers related to documents.
  * Lots of duplicated code here that should get consolidated at some point.
  */
-import type { Document, sizes } from "./types";
+import type { Document, DocumentResults, SearchOptions, sizes } from "./types";
 
 import { error } from "@sveltejs/kit";
 
@@ -10,17 +10,29 @@ import { isOrg } from "@/api/types/orgAndUser";
 import { APP_URL, BASE_API_URL } from "@/config/config.js";
 import { isErrorCode } from "../utils";
 
-/** Search documents */
+/**
+ * Search documents
+ * https://www.documentcloud.org/help/search/
+ *
+ *  */
 export async function search(
   query = "",
-  highlight = false,
+  options: SearchOptions = {
+    hl: Boolean(query),
+    per_page: 25,
+    cursor: "",
+    version: "2.0",
+  },
   fetch = globalThis.fetch,
-) {
+): Promise<DocumentResults> {
   const endpoint = new URL("documents/search/", BASE_API_URL);
 
   endpoint.searchParams.set("expand", DEFAULT_EXPAND);
   endpoint.searchParams.set("q", query);
-  endpoint.searchParams.set("hl", String(highlight));
+
+  for (const [k, v] of Object.entries(options)) {
+    endpoint.searchParams.set(k, String(v));
+  }
 
   const resp = await fetch(endpoint, { credentials: "include" });
 
diff --git a/src/lib/api/types.d.ts b/src/lib/api/types.d.ts
index d686d6680..474da49ee 100644
--- a/src/lib/api/types.d.ts
+++ b/src/lib/api/types.d.ts
@@ -105,7 +105,6 @@ export interface Document {
   note_highlights?: Record<string, Highlight[]>;
 }
 
-// export type DocumentResults = Page<Document>;
 export interface DocumentResults extends Page<Document> {}
 
 export interface Note {
@@ -135,6 +134,14 @@ export interface Section {
 
 export type SectionResults = Page<Section>;
 
+export interface SearchOptions {
+  hl?: boolean;
+  per_page?: number;
+  cursor?: string;
+  expand?: string;
+  version?: number | string;
+}
+
 export interface OEmbed {
   version: "1.0";
   provider_name: "DocumentCloud";
diff --git a/src/lib/components/Search.svelte b/src/lib/components/Search.svelte
index b60959d78..a6e59aa50 100644
--- a/src/lib/components/Search.svelte
+++ b/src/lib/components/Search.svelte
@@ -1,6 +1,5 @@
 <script lang="ts">
   import { Search24, XCircleFill24 } from "svelte-octicons";
-  import Button from "./common/Button.svelte";
 
   export let query: string = "";
   let input: HTMLInputElement;
@@ -11,16 +10,19 @@
   }
 </script>
 
-<form class="container" on:submit|preventDefault>
+<form class="container" on:submit>
   <label for="query" title="Search"><Search24 /></label>
   <input
+    type="search"
     id="query"
-    name="query"
+    name="q"
+    autocomplete="off"
+    placeholder="Search…"
     bind:value={query}
     bind:this={input}
     on:change
-    autocomplete="off"
-    placeholder="Search…"
+    on:input
+    on:reset
   />
   <button
     title="Clear Search"
diff --git a/src/lib/components/documents/ResultsList.svelte b/src/lib/components/documents/ResultsList.svelte
index f0fd5ccd1..a1a679fe3 100644
--- a/src/lib/components/documents/ResultsList.svelte
+++ b/src/lib/components/documents/ResultsList.svelte
@@ -1,37 +1,53 @@
 <script context="module" lang="ts">
   import { writable, type Writable } from "svelte/store";
+  import Button from "../common/Button.svelte";
 
   export const selected: Writable<(number | string)[]> = writable([]);
 </script>
 
 <script lang="ts">
+  import type { Document, DocumentResults } from "$lib/api/types";
+
   import { _ } from "svelte-i18n";
-  import type { DocumentResults } from "$lib/api/types";
+
   import DocumentListItem from "./DocumentListItem.svelte";
   import Flex from "../common/Flex.svelte";
-  import Checkbox from "../common/Checkbox.svelte";
   import { Search24 } from "svelte-octicons";
   import Empty from "../common/Empty.svelte";
 
-  export let results: DocumentResults = undefined;
+  export let results: Document[] = [];
+  export let count: number = undefined;
+  export let next: string | null = null;
+
+  let loading = false;
 
-  function updateSelection(event: Event, id: string | number) {
-    const { checked } = event.target as HTMLInputElement;
-    if (checked) {
-      selected.set([...$selected, id]);
-    } else {
-      selected.set([...$selected.filter((d) => d !== id)]);
+  // load the next set of results
+  async function load(url: URL) {
+    loading = true;
+    const res = await fetch(url, { credentials: "include" });
+
+    if (!res.ok) {
+      // todo: better error handling
+      console.error(res.statusText);
+      loading = false;
     }
+
+    const r: DocumentResults = await res.json();
+
+    results = [...results, ...r.results];
+    count = r.count;
+    next = r.next;
+    loading = false;
   }
 </script>
 
 <div class="container">
-  {#each results.results as document (document.id)}
+  {#each results as document (document.id)}
     <Flex gap={0.625} align="center">
-      <Checkbox
-        checked={$selected.includes(document.id)}
-        on:change={(event) => updateSelection(event, document.id)}
-      />
+      <label>
+        <span class="sr-only">Select</span>
+        <input type="checkbox" bind:group={$selected} value={document.id} />
+      </label>
       <DocumentListItem {document} />
     </Flex>
   {:else}
@@ -40,10 +56,26 @@
       <p>{$_("noDocuments.queryNoResults")}</p>
     </Empty>
   {/each}
+  <div class="end">
+    {#if next}
+      <Button on:click={(e) => load(new URL(next))}>Load more</Button>
+    {/if}
+  </div>
 </div>
 
 <style>
   .container {
     padding: 0 2rem;
   }
+
+  label {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+  }
+
+  input[type="checkbox"] {
+    height: 1.25rem;
+    width: 1.25rem;
+  }
 </style>
diff --git a/src/lib/components/documents/stories/ResultsList.stories.svelte b/src/lib/components/documents/stories/ResultsList.stories.svelte
index 886307168..360d7dc3b 100644
--- a/src/lib/components/documents/stories/ResultsList.stories.svelte
+++ b/src/lib/components/documents/stories/ResultsList.stories.svelte
@@ -1,11 +1,13 @@
 <script context="module" lang="ts">
-  import type { DocumentResults } from "@/lib/api/types";
+  import type { Document, DocumentResults } from "@/lib/api/types";
   import { Story } from "@storybook/addon-svelte-csf";
   import ResultsList from "../ResultsList.svelte";
 
   // typescript complains without the type assertion
   import searchResults from "../../../api/fixtures/documents/search-highlight.json";
-  const results = searchResults as DocumentResults;
+  const results = searchResults.results as Document[];
+  const count = searchResults.count;
+  const next = searchResults.next;
 
   export const meta = {
     title: "Components / Documents / Results list",
@@ -13,20 +15,12 @@
     tags: ["autodocs"],
     parameters: { layout: "centered" },
   };
-
-  const empty = {
-    results: [],
-    count: 0,
-    next: null,
-    previous: null,
-    escaped: false,
-  };
 </script>
 
 <Story name="With Results">
-  <div style="width: 36rem"><ResultsList {results} /></div>
+  <div style="width: 36rem"><ResultsList {results} {count} {next} /></div>
 </Story>
 
 <Story name="Empty">
-  <div style="width: 36rem"><ResultsList results={empty} /></div>
+  <div style="width: 36rem"><ResultsList /></div>
 </Story>
diff --git a/src/routes/app/+page.svelte b/src/routes/app/+page.svelte
index 08702a3fd..2a1f76f74 100644
--- a/src/routes/app/+page.svelte
+++ b/src/routes/app/+page.svelte
@@ -6,35 +6,11 @@
   import PageToolbar from "$lib/components/common/PageToolbar.svelte";
   import Search from "$lib/components/Search.svelte";
   import Empty from "$lib/components/common/Empty.svelte";
-  import Paginator from "@/common/Paginator.svelte";
-  import type { DocumentResults } from "@/lib/api/types";
 
-  export let data: {
-    query: string;
-    searchResults: Promise<DocumentResults>;
-  };
-
-  let page = 1;
-  let per_page = 25;
-  let error: Error;
+  export let data;
 
   $: searchResults = data.searchResults;
   $: query = data.query;
-
-  async function load(url) {
-    const res = await fetch(url, { credentials: "include" }).catch((e) => {
-      error = e;
-      throw e; // if something went wrong here, something broke
-    });
-
-    if (!res.ok) {
-      // 404 or something similar
-      console.error(res.statusText);
-      error = { name: "Loading error", message: res.statusText };
-    }
-
-    data.searchResults = res.json();
-  }
 </script>
 
 <ContentLayout>
@@ -44,7 +20,11 @@
   {#await searchResults}
     <Empty icon={Hourglass24}>Loading…</Empty>
   {:then results}
-    <ResultsList {results} />
+    <ResultsList
+      results={results.results}
+      count={results.count}
+      next={results.next}
+    />
   {/await}
 
   <PageToolbar slot="footer">
@@ -52,37 +32,5 @@
       <input type="checkbox" name="select_all" />
       Select all
     </label>
-
-    <svelte:fragment slot="center">
-      {#await searchResults then sr}
-        {@const count = sr.count}
-        {@const total_pages = Math.ceil(count / per_page)}
-        {@const next = sr.next}
-        {@const previous = sr.previous}
-        <Paginator
-          {page}
-          totalPages={total_pages}
-          has_next={Boolean(next)}
-          has_previous={Boolean(previous)}
-          on:next={(e) => {
-            page = Math.min(total_pages, page + 1);
-            load(next);
-          }}
-          on:previous={(e) => {
-            page = Math.max(1, page - 1);
-            load(previous);
-          }}
-        />
-      {/await}
-    </svelte:fragment>
-
-    <label slot="right">
-      Per page
-      <select name="per_page" bind:value={per_page}>
-        <option value={25}>25</option>
-        <option value={50}>50</option>
-        <option value={100}>100</option>
-      </select>
-    </label>
   </PageToolbar>
 </ContentLayout>
diff --git a/src/routes/app/+page.ts b/src/routes/app/+page.ts
index 2798376c6..cf9984f05 100644
--- a/src/routes/app/+page.ts
+++ b/src/routes/app/+page.ts
@@ -1,11 +1,30 @@
-import { search } from "$lib/api/documents.js";
+import type { SearchOptions } from "$lib/api/types";
+import { search } from "$lib/api/documents";
 
 export async function load({ url, fetch }) {
   const query = url.searchParams.get("q") || "";
-  const searchResults = search(query, true, fetch);
+  const per_page = +url.searchParams.get("per_page") || 25;
+  const cursor = url.searchParams.get("cursor") || "";
+
+  const options: SearchOptions = {
+    hl: Boolean(query),
+    version: "2.0",
+  };
+
+  if (per_page) {
+    options.per_page = per_page;
+  }
+
+  if (cursor) {
+    options.cursor = cursor;
+  }
+
+  const searchResults = search(query, options, fetch);
 
   return {
-    searchResults,
     query,
+    per_page,
+    cursor,
+    searchResults,
   };
 }
diff --git a/src/style/kit.css b/src/style/kit.css
index d0b920685..1965f00cd 100644
--- a/src/style/kit.css
+++ b/src/style/kit.css
@@ -139,3 +139,21 @@ dd {
   font-size: var(--font-s, 0.875rem);
   font-weight: var(--font-regular, 400);
 }
+
+/*
+Utility classes
+*/
+
+/* https://css-tricks.com/inclusively-hidden/
+ * Hiding class, making content visible only to screen readers but not visually
+ * "sr" meaning "screen-reader" 
+ */
+.sr-only:not(:focus):not(:active) {
+  clip: rect(0 0 0 0);
+  clip-path: inset(50%);
+  height: 1px;
+  overflow: hidden;
+  position: absolute;
+  white-space: nowrap;
+  width: 1px;
+}