import/export logic refactored into separate files per format, closes #237

src/services/export/native_tar.js

@@ -0,0 +1,103 @@
+"use strict";
+
+const html = require('html');
+const native_tar = require('tar-stream');
+const sanitize = require("sanitize-filename");
+
+async function exportToTar(branch, res) {
+    const pack = native_tar.pack();
+
+    const exportedNoteIds = [];
+    const name = await exportNoteInner(branch, '');
+
+    async function exportNoteInner(branch, directory) {
+        const note = await branch.getNote();
+        const childFileName = directory + sanitize(note.title);
+
+        if (exportedNoteIds.includes(note.noteId)) {
+            saveMetadataFile(childFileName, {
+                version: 1,
+                clone: true,
+                noteId: note.noteId,
+                prefix: branch.prefix
+            });
+
+            return;
+        }
+
+        const metadata = {
+            version: 1,
+            clone: false,
+            noteId: note.noteId,
+            title: note.title,
+            prefix: branch.prefix,
+            isExpanded: branch.isExpanded,
+            type: note.type,
+            mime: note.mime,
+            // we don't export dateCreated and dateModified of any entity since that would be a bit misleading
+            attributes: (await note.getOwnedAttributes()).map(attribute => {
+                return {
+                    type: attribute.type,
+                    name: attribute.name,
+                    value: attribute.value,
+                    isInheritable: attribute.isInheritable,
+                    position: attribute.position
+                };
+            }),
+            links: (await note.getLinks()).map(link => {
+                return {
+                    type: link.type,
+                    targetNoteId: link.targetNoteId
+                }
+            })
+        };
+
+        if (await note.hasLabel('excludeFromExport')) {
+            return;
+        }
+
+        saveMetadataFile(childFileName, metadata);
+        saveDataFile(childFileName, note);
+
+        exportedNoteIds.push(note.noteId);
+
+        const childBranches = await note.getChildBranches();
+
+        if (childBranches.length > 0) {
+            saveDirectory(childFileName);
+        }
+
+        for (const childBranch of childBranches) {
+            await exportNoteInner(childBranch, childFileName + "/");
+        }
+
+        return childFileName;
+    }
+
+    function saveDataFile(childFileName, note) {
+        const content = note.type === 'text' ? html.prettyPrint(note.content, {indent_size: 2}) : note.content;
+
+        pack.entry({name: childFileName + ".dat", size: content.length}, content);
+    }
+
+    function saveMetadataFile(childFileName, metadata) {
+        const metadataJson = JSON.stringify(metadata, null, '\t');
+
+        pack.entry({name: childFileName + ".meta", size: metadataJson.length}, metadataJson);
+    }
+
+    function saveDirectory(childFileName) {
+        pack.entry({name: childFileName, type: 'directory'});
+    }
+
+    pack.finalize();
+
+    res.setHeader('Content-Disposition', 'file; filename="' + name + '.tar"');
+    res.setHeader('Content-Type', 'application/tar');
+
+    pack.pipe(res);
+}
+
+module.exports = {
+    exportToTar
+};