feat: render CSVs as table (#5569)

Co-authored-by: Henrique Dias <mail@hacdias.com>

frontend/src/components/files/CsvViewer.vue

@@ -0,0 +1,202 @@
+<template>
+  <div class="csv-viewer">
+    <div v-if="displayError" class="csv-error">
+      <i class="material-icons">error</i>
+      <p>{{ displayError }}</p>
+    </div>
+    <div v-else-if="data.headers.length === 0" class="csv-empty">
+      <i class="material-icons">description</i>
+      <p>{{ $t("files.lonely") }}</p>
+    </div>
+    <div
+      v-else
+      class="csv-table-container"
+      @wheel.stop
+      @touchmove.stop
+    >
+      <table class="csv-table">
+        <thead>
+          <tr>
+            <th v-for="(header, index) in data.headers" :key="index">
+              {{ header || `Column ${index + 1}` }}
+            </th>
+          </tr>
+        </thead>
+        <tbody>
+          <tr v-for="(row, rowIndex) in data.rows" :key="rowIndex">
+            <td v-for="(cell, cellIndex) in row" :key="cellIndex">
+              {{ cell }}
+            </td>
+          </tr>
+        </tbody>
+      </table>
+      <div v-if="data.rows.length > 100" class="csv-info">
+        <i class="material-icons">info</i>
+        <span>Showing {{ data.rows.length }} rows</span>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { parseCSV, type CsvData } from "@/utils/csv";
+import { computed } from "vue";
+
+interface Props {
+  content: string;
+  error?: string;
+}
+
+const props = withDefaults(defineProps<Props>(), {
+  error: "",
+});
+
+const data = computed<CsvData>(() => {
+  try {
+    return parseCSV(props.content);
+  } catch (e) {
+    console.error("Failed to parse CSV:", e);
+    return { headers: [], rows: [] };
+  }
+});
+
+const displayError = computed(() => {
+  // External error takes priority (e.g., file too large)
+  if (props.error) {
+    return props.error;
+  }
+  // Check for parse errors
+  if (props.content && props.content.trim().length > 0 && data.value.headers.length === 0) {
+    return "Failed to parse CSV file";
+  }
+  return null;
+});
+</script>
+
+<style scoped>
+.csv-viewer {
+  width: 100%;
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+  background-color: var(--surfacePrimary);
+  color: var(--textSecondary);
+  padding: 1rem;
+  padding-top: 4em;
+  box-sizing: border-box;
+}
+
+.csv-error,
+.csv-empty {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  height: 100%;
+  gap: 1rem;
+  color: var(--textPrimary);
+}
+
+.csv-error i,
+.csv-empty i {
+  font-size: 4rem;
+  opacity: 0.5;
+}
+
+.csv-error p,
+.csv-empty p {
+  font-size: 1.1rem;
+  margin: 0;
+}
+
+.csv-table-container {
+  flex: 1;
+  overflow: auto;
+  background-color: var(--surfacePrimary);
+  border-radius: 4px;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
+}
+
+/* Scrollbar styling for better visibility */
+.csv-table-container::-webkit-scrollbar {
+  width: 12px;
+  height: 12px;
+}
+
+.csv-table-container::-webkit-scrollbar-track {
+  background: var(--background);
+  border-radius: 4px;
+}
+
+.csv-table-container::-webkit-scrollbar-thumb {
+  background: var(--borderSecondary);
+  border-radius: 4px;
+}
+
+.csv-table-container::-webkit-scrollbar-thumb:hover {
+  background: var(--textPrimary);
+}
+
+.csv-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 0.875rem;
+  background-color: var(--surfacePrimary);
+}
+
+.csv-table thead {
+  position: sticky;
+  top: 0;
+  z-index: 10;
+  background-color: var(--surfaceSecondary);
+}
+
+.csv-table th {
+  padding: 0.875rem 1rem;
+  text-align: left;
+  font-weight: 600;
+  border-bottom: 2px solid var(--borderSecondary);
+  background-color: var(--surfaceSecondary);
+  white-space: nowrap;
+  color: var(--textSecondary);
+  font-size: 0.875rem;
+}
+
+.csv-table td {
+  padding: 0.75rem 1rem;
+  text-align: left;
+  border-bottom: 1px solid var(--borderPrimary);
+  white-space: nowrap;
+  max-width: 400px;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  color: var(--textSecondary);
+}
+
+.csv-table tbody tr:nth-child(even) {
+  background-color: var(--background);
+}
+
+.csv-table tbody tr:hover {
+  background-color: var(--hover);
+  transition: background-color 0.15s ease;
+}
+
+.csv-info {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  padding: 0.75rem 1rem;
+  margin-top: 0.5rem;
+  background-color: var(--surfaceSecondary);
+  border-radius: 4px;
+  border-left: 3px solid var(--blue);
+  color: var(--textSecondary);
+  font-size: 0.875rem;
+}
+
+.csv-info i {
+  font-size: 1.2rem;
+  color: var(--blue);
+}
+</style>

frontend/src/i18n/en.json

@@ -43,7 +43,8 @@
     "upload": "Upload",
     "openFile": "Open file",
     "discardChanges": "Discard",
-    "saveChanges": "Save changes"
+    "saveChanges": "Save changes",
+    "editAsText": "Edit as Text"
   },
   "download": {
     "downloadFile": "Download File",
@@ -75,7 +76,9 @@
     "sortByLastModified": "Sort by last modified",
     "sortByName": "Sort by name",
     "sortBySize": "Sort by size",
-    "noPreview": "Preview is not available for this file."
+    "noPreview": "Preview is not available for this file.",
+    "csvTooLarge": "CSV file is too large for preview (>5MB). Please download to view.",
+    "csvLoadFailed": "Failed to load CSV file."
   },
   "help": {
     "click": "select file or directory",

frontend/src/utils/csv.ts

@@ -0,0 +1,61 @@
+export interface CsvData {
+  headers: string[];
+  rows: string[][];
+}
+
+/**
+ * Parse CSV content into headers and rows
+ * Supports quoted fields and handles commas within quotes
+ */
+export function parseCSV(content: string): CsvData {
+  if (!content || content.trim().length === 0) {
+    return { headers: [], rows: [] };
+  }
+
+  const lines = content.split(/\r?\n/);
+  const result: string[][] = [];
+
+  for (const line of lines) {
+    if (line.trim().length === 0) continue;
+
+    const row: string[] = [];
+    let currentField = "";
+    let inQuotes = false;
+
+    for (let i = 0; i < line.length; i++) {
+      const char = line[i];
+      const nextChar = line[i + 1];
+
+      if (char === '"') {
+        if (inQuotes && nextChar === '"') {
+          // Escaped quote
+          currentField += '"';
+          i++; // Skip next quote
+        } else {
+          // Toggle quote state
+          inQuotes = !inQuotes;
+        }
+      } else if (char === "," && !inQuotes) {
+        // Field separator
+        row.push(currentField);
+        currentField = "";
+      } else {
+        currentField += char;
+      }
+    }
+
+    // Add the last field
+    row.push(currentField);
+    result.push(row);
+  }
+
+  if (result.length === 0) {
+    return { headers: [], rows: [] };
+  }
+
+  // First row is headers
+  const headers = result[0];
+  const rows = result.slice(1);
+
+  return { headers, rows };
+}

frontend/src/views/Files.vue

@@ -69,6 +69,12 @@ const currentView = computed(() => {
 
   if (fileStore.req.isDir) {
     return FileListing;
+  } else if (fileStore.req.extension.toLowerCase() === ".csv") {
+    // CSV files use Preview for table view, unless ?edit=true
+    if (route.query.edit === "true") {
+      return Editor;
+    }
+    return Preview;
   } else if (
     fileStore.req.type === "text" ||
     fileStore.req.type === "textImmutable"

frontend/src/views/files/Preview.vue

@@ -6,7 +6,7 @@
     @mousemove="toggleNavigation"
     @touchstart="toggleNavigation"
   >
-    <header-bar v-if="isPdf || isEpub || showNav">
+    <header-bar v-if="isPdf || isEpub || isCsv || showNav">
       <action icon="close" :label="$t('buttons.close')" @action="close()" />
       <title>{{ name }}</title>
       <action
@@ -24,6 +24,13 @@
           :label="$t('buttons.rename')"
           show="rename"
         />
+        <action
+          :disabled="layoutStore.loading"
+          v-if="isCsv && authStore.user?.perm.modify"
+          icon="edit_note"
+          :label="t('buttons.editAsText')"
+          @action="editAsText"
+        />
         <action
           :disabled="layoutStore.loading"
           v-if="authStore.user?.perm.delete"
@@ -87,6 +94,7 @@
             <span>{{ size }}%</span>
           </div>
         </div>
+        <CsvViewer v-else-if="isCsv" :content="csvContent" :error="csvError" />
         <ExtendedImage
           v-else-if="fileStore.req?.type == 'image'"
           :src="previewUrl"
@@ -176,11 +184,17 @@ import HeaderBar from "@/components/header/HeaderBar.vue";
 import Action from "@/components/header/Action.vue";
 import ExtendedImage from "@/components/files/ExtendedImage.vue";
 import VideoPlayer from "@/components/files/VideoPlayer.vue";
+import CsvViewer from "@/components/files/CsvViewer.vue";
 import { VueReader } from "vue-reader";
 import { computed, inject, onBeforeUnmount, onMounted, ref, watch } from "vue";
 import { useRoute, useRouter } from "vue-router";
 import type { Rendition } from "epubjs";
 import { getTheme } from "@/utils/theme";
+import { useI18n } from "vue-i18n";
+
+// CSV file size limit for preview (5MB)
+// Prevents browser memory issues with large files
+const CSV_MAX_SIZE = 5 * 1024 * 1024;
 
 const location = useStorage("book-progress", 0, undefined, {
   serializer: {
@@ -239,6 +253,8 @@ const hoverNav = ref<boolean>(false);
 const autoPlay = ref<boolean>(false);
 const previousRaw = ref<string>("");
 const nextRaw = ref<string>("");
+const csvContent = ref<string>("");
+const csvError = ref<string>("");
 
 const player = ref<HTMLVideoElement | HTMLAudioElement | null>(null);
 
@@ -248,6 +264,8 @@ const authStore = useAuthStore();
 const fileStore = useFileStore();
 const layoutStore = useLayoutStore();
 
+const { t } = useI18n();
+
 const route = useRoute();
 const router = useRouter();
 
@@ -279,6 +297,7 @@ const isPdf = computed(() => fileStore.req?.extension.toLowerCase() == ".pdf");
 const isEpub = computed(
   () => fileStore.req?.extension.toLowerCase() == ".epub"
 );
+const isCsv = computed(() => fileStore.req?.extension.toLowerCase() == ".csv");
 
 const isResizeEnabled = computed(() => resizePreview);
 
@@ -366,6 +385,18 @@ const updatePreview = async () => {
   const dirs = route.fullPath.split("/");
   name.value = decodeURIComponent(dirs[dirs.length - 1]);
 
+  // Load CSV content if it's a CSV file
+  if (isCsv.value && fileStore.req) {
+    csvContent.value = "";
+    csvError.value = "";
+
+    if (fileStore.req.size > CSV_MAX_SIZE) {
+      csvError.value = t("files.csvTooLarge");
+    } else {
+      csvContent.value = fileStore.req.content ?? "";
+    }
+  }
+
   if (!listing.value) {
     try {
       const path = url.removeLastDir(route.path);
@@ -435,4 +466,8 @@ const close = () => {
 };
 
 const download = () => window.open(downloadUrl.value);
+
+const editAsText = () => {
+  router.push({ path: route.path, query: { edit: "true" } });
+};
 </script>