feat: add file preview modal (#945)

app/assets/javascripts/services/archiveManager.ts

@@ -24,6 +24,8 @@ type ZippableData = {
   content: Blob;
 }[];
 
+type ObjectURL = string;
+
 export class ArchiveManager {
   private readonly application: WebApplication;
   private textFile?: string;
@@ -32,6 +34,10 @@ export class ArchiveManager {
     this.application = application;
   }
 
+  public async getMimeType(ext: string) {
+    return (await import('@zip.js/zip.js')).getMimeType(ext);
+  }
+
   public async downloadBackup(encrypted: boolean): Promise<void> {
     const intent = encrypted
       ? EncryptionIntent.FileEncrypted
@@ -150,10 +156,10 @@ export class ArchiveManager {
     return this.textFile;
   }
 
-  downloadData(data: Blob, fileName: string) {
+  downloadData(data: Blob | ObjectURL, fileName: string) {
     const link = document.createElement('a');
     link.setAttribute('download', fileName);
-    link.href = this.hrefForData(data);
+    link.href = typeof data === 'string' ? data : this.hrefForData(data);
     document.body.appendChild(link);
     link.click();
     link.remove();