Support downloading files from zip files in filesystem

svelte/src/filesystem/viewers/Zip.svelte

@@ -1,7 +1,7 @@
 <script>
 import { createEventDispatcher } from "svelte";
 import { formatDataVolume, formatDate } from "../../util/Formatting.svelte"
-import ZipItem from "./ZipItem.svelte";
+import ZipItem from "../../file_viewer/viewers/ZipItem.svelte";
 import IconBlock from "../../file_viewer/viewers/IconBlock.svelte";
 import TextBlock from "../../file_viewer/viewers/TextBlock.svelte";
 import { fs_node_icon, fs_path_url } from "../FilesystemUtil";
@@ -18,10 +18,17 @@ let zip = {
 }
 let uncomp_size = 0
 let comp_ratio = 0
+let archive_type = ""
 
 export const update = async () => {
 	dispatch("loading", true)
 
+	if (state.base.file_type === "application/zip") {
+		archive_type = "zip"
+	} else if (state.base.file_type === "application/x-7z-compressed") {
+		archive_type = "7z"
+	}
+
 	try {
 		let resp = await fetch(fs_path_url(state.base.path)+"?zip_info")
 
@@ -32,6 +39,13 @@ export const update = async () => {
 
 		zip = await resp.json()
 
+		// Check if the zip has the property which allows separate files to be
+		// downloaded. If so then we set the download URL for each file
+		if (zip.properties && zip.properties.includes("read_individual_files")) {
+			// Set the download URL for each file in the zip
+			recursive_set_url(fs_path_url(state.base.path)+"?zip_file=", zip)
+		}
+
 		uncomp_size = recursive_size(zip)
 		comp_ratio = (uncomp_size / state.base.file_size)
 	} catch (err) {
@@ -43,6 +57,16 @@ export const update = async () => {
 	status = "finished"
 }
 
+const recursive_set_url = (parent_path, file) => {
+	file.download_url = parent_path
+
+	if (file.children) {
+		Object.entries(file.children).forEach(child => {
+			recursive_set_url(file.download_url + "/" + child[0], child[1])
+		});
+	}
+}
+
 const recursive_size = (file) => {
 	let size = file.size
 
@@ -64,8 +88,14 @@ const recursive_size = (file) => {
 <h1>{state.base.name}</h1>
 
 <IconBlock icon_href={fs_node_icon(state.base, 256, 256)}>
+	{#if archive_type === "7z"}
+		This is a 7-zip archive. You will need
+		<a href="https://www.7-zip.org/">7-zip</a> or compatible software to
+		extract it<br/>
+	{/if}
+
 	Compressed size: {formatDataVolume(state.base.file_size, 3)}<br/>
-	Uncompressed size: {formatDataVolume(uncomp_size, 3)} (Ratio: {comp_ratio.toFixed(2)}x)<br/>
+	Uncompressed size: {formatDataVolume(zip.size, 3)} (Ratio: {comp_ratio.toFixed(2)}x)<br/>
 	Uploaded on: {formatDate(state.base.created, true, true, true)}
 	<br/>
 	<button class="button_highlight" on:click={() => {dispatch("download")}}>