fork from https://github.com/mozilla/pdf.js.git

web/base_download_manager.js

@@ -0,0 +1,102 @@
+/* Copyright 2013 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { isPdfFile } from "pdfjs-lib";
+
+class BaseDownloadManager {
+  #openBlobUrls = new WeakMap();
+
+  constructor() {
+    if (
+      (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) &&
+      this.constructor === BaseDownloadManager
+    ) {
+      throw new Error("Cannot initialize BaseDownloadManager.");
+    }
+  }
+
+  _triggerDownload(blobUrl, originalUrl, filename, isAttachment = false) {
+    throw new Error("Not implemented: _triggerDownload");
+  }
+
+  _getOpenDataUrl(blobUrl, filename, dest = null) {
+    throw new Error("Not implemented: _getOpenDataUrl");
+  }
+
+  /**
+   * @param {Uint8Array} data
+   * @param {string} filename
+   * @param {string} [contentType]
+   */
+  downloadData(data, filename, contentType) {
+    const blobUrl = URL.createObjectURL(
+      new Blob([data], { type: contentType })
+    );
+
+    this._triggerDownload(
+      blobUrl,
+      /* originalUrl = */ blobUrl,
+      filename,
+      /* isAttachment = */ true
+    );
+  }
+
+  /**
+   * @param {Uint8Array} data
+   * @param {string} filename
+   * @param {string | null} [dest]
+   * @returns {boolean} Indicating if the data was opened.
+   */
+  openOrDownloadData(data, filename, dest = null) {
+    const isPdfData = isPdfFile(filename);
+    const contentType = isPdfData ? "application/pdf" : "";
+
+    if (isPdfData) {
+      const blobUrl = this.#openBlobUrls.getOrInsertComputed(data, () =>
+        URL.createObjectURL(new Blob([data], { type: contentType }))
+      );
+      try {
+        const viewerUrl = this._getOpenDataUrl(blobUrl, filename, dest);
+
+        window.open(viewerUrl);
+        return true;
+      } catch (ex) {
+        console.error("openOrDownloadData:", ex);
+        // Release the `blobUrl`, since opening it failed, and fallback to
+        // downloading the PDF file.
+        URL.revokeObjectURL(blobUrl);
+        this.#openBlobUrls.delete(data);
+      }
+    }
+
+    this.downloadData(data, filename, contentType);
+    return false;
+  }
+
+  /**
+   * @param {Uint8Array} data
+   * @param {string} url
+   * @param {string} filename
+   */
+  download(data, url, filename) {
+    const blobUrl = data
+      ? URL.createObjectURL(new Blob([data], { type: "application/pdf" }))
+      : null;
+
+    this._triggerDownload(blobUrl, /* originalUrl = */ url, filename);
+  }
+}
+
+export { BaseDownloadManager };