Sketch for fixing #8456

changelog/unreleased/enhancement-respect-archiver-limits

@@ -0,0 +1,8 @@
+Enhancement: Respect archiver limits
+
+The archiver service can now announce a limit for both the amount of resources and 
+the size of the currently selected resources. The web UI now respects those limits 
+and shows a disabled download button once the limit has been reached.
+
+https://github.com/owncloud/web/pull/9055
+https://github.com/owncloud/web/issues/8456

packages/design-system/changelog/7.0.0_2021-05-31/bugfix-interactive-oc-tooltip-texts

@@ -1,6 +1,6 @@
 Bugfix: Interactive texts in OcTooltips
 
 The new tooltip texts would only be initialized once and then didn't offer 
-the possibility of chaging reactively. By updating the directive, we've changed that.
+the possibility of changing reactively. By updating the directive, we've changed that.
 
 https://github.com/owncloud/owncloud-design-system/pull/1288

packages/web-app-files/src/composables/actions/files/useFileActionsDownloadArchive.ts

@@ -59,6 +59,29 @@ export const useFileActionsDownloadArchive = ({ store }: { store?: Store<any> }
       })
   }
 
+  const archiverLimitsExceeded = (resources: Resource[]) => {
+    const archiverCapabilities = archiverService.capability
+    if (!archiverCapabilities) {
+      return
+    }
+
+    const selectedFilesAmount = resources.length
+
+    // TODO: selectedFilesSize doesn't traverse into folders, so currently limited to directly selected resources
+    const selectedFilesSize = resources.reduce(
+      (accumulator, currentValue) =>
+        accumulator +
+        (typeof currentValue.size === 'string' ? parseInt(currentValue.size) : currentValue.size),
+      0
+    )
+
+    return (
+      selectedFilesAmount > parseInt(archiverCapabilities.max_num_files) ||
+      // TODO: Check whether archiver and web use the same base for filesize calculation
+      selectedFilesSize > parseInt(archiverCapabilities.max_size)
+    )
+  }
+
   const actions = computed((): FileAction[] => {
     return [
       {
@@ -68,6 +91,12 @@ export const useFileActionsDownloadArchive = ({ store }: { store?: Store<any> }
         label: () => {
           return $gettext('Download')
         },
+        disabledTooltip: ({ resources }) => {
+          return archiverLimitsExceeded(resources)
+            ? $gettext('Unable to download that many files at once')
+            : ''
+        },
+        isDisabled: ({ resources }) => archiverLimitsExceeded(resources),
         isEnabled: ({ resources }) => {
           if (
             unref(isFilesAppActive) &&

packages/web-app-files/src/services/archiver.ts

@@ -17,6 +17,8 @@ export interface ArchiverCapability {
   formats: string[]
   // eslint-disable-next-line camelcase
   archiver_url: string
+  max_num_files: string
+  max_size: string
 }
 
 interface TriggerDownloadOptions {

packages/web-pkg/src/components/ContextActions/ActionMenuItem.vue

@@ -1,5 +1,5 @@
 <template>
-  <li>
+  <li v-oc-tooltip="componentProps.disabled ? action.disabledTooltip(actionOptions) : ''">
     <oc-button
       v-oc-tooltip="showTooltip || action.hideLabel ? action.label(actionOptions) : ''"
       :type="action.componentType"
@@ -35,8 +35,9 @@
         v-if="!action.hideLabel"
         class="oc-files-context-action-label"
         data-testid="action-label"
-        >{{ action.label(actionOptions) }}</span
       >
+        {{ action.label(actionOptions) }}
+      </span>
       <span
         v-if="action.shortcut && shortcutHint"
         class="oc-files-context-action-shortcut"

packages/web-pkg/src/composables/actions/types.ts

@@ -29,6 +29,7 @@ export interface Action<T = ActionOptions> {
 
   // can be used to display the action in a disabled state in the UI
   isDisabled?(options?: T): boolean
+  disabledTooltip?(options?: T): string
 }
 
 export type FileActionOptions = {