fix(web): align document drop state (WTA-2106)

Linear: https://linear.app/dify/issue/WTA-2106

web/features/new-rag/__tests__/documents-page.spec.tsx

@@ -1773,7 +1773,7 @@ describe('DocumentsPage', () => {
     ).not.toBeInTheDocument()
   })
 
-  it('opens the upload form when files are dropped on a populated document page', () => {
+  it('shows the drop target while dragging and previews dropped files in the upload form', () => {
     documentsQuery.data = { pages: [{ items: [document()] }] }
     const droppedFile = new File(['# handbook'], 'handbook.md', { type: 'text/markdown' })
 
@@ -1783,6 +1783,21 @@ describe('DocumentsPage', () => {
       .getByRole('heading', { name: 'dataset.newKnowledge.documents' })
       .closest('section')
     expect(documentSurface).not.toBeNull()
+    fireEvent.dragEnter(documentSurface!, {
+      dataTransfer: { files: [droppedFile], types: ['Files'] },
+    })
+
+    expect(screen.getByText('dataset.newKnowledge.dropFilesHere')).toBeInTheDocument()
+
+    fireEvent.dragLeave(documentSurface!, {
+      dataTransfer: { files: [droppedFile], types: ['Files'] },
+    })
+
+    expect(screen.queryByText('dataset.newKnowledge.dropFilesHere')).not.toBeInTheDocument()
+
+    fireEvent.dragEnter(documentSurface!, {
+      dataTransfer: { files: [droppedFile], types: ['Files'] },
+    })
     fireEvent.drop(documentSurface!, {
       dataTransfer: {
         dropEffect: 'copy',
@@ -1794,9 +1809,38 @@ describe('DocumentsPage', () => {
     expect(
       screen.getByRole('heading', { name: 'dataset.newKnowledge.addDocument' }),
     ).toBeInTheDocument()
+    expect(screen.queryByText('dataset.newKnowledge.dropFilesHere')).not.toBeInTheDocument()
     expect(screen.getByText('handbook.md')).toBeInTheDocument()
   })
 
+  it('keeps the designed drop target active over the open upload form', async () => {
+    const droppedFile = new File(['# handbook'], 'handbook.md', { type: 'text/markdown' })
+
+    render(<DocumentsPage knowledgeSpaceId="space-1" />, { searchParams: '?upload=1' })
+
+    const documentSurface = screen
+      .getByRole('heading', { name: 'dataset.newKnowledge.addDocument' })
+      .closest('section')
+    expect(documentSurface).not.toBeNull()
+
+    fireEvent.dragEnter(documentSurface!, {
+      dataTransfer: { files: [droppedFile], types: ['Files'] },
+    })
+
+    expect(screen.getByText('dataset.newKnowledge.dropFilesHere')).toBeInTheDocument()
+
+    fireEvent.drop(documentSurface!, {
+      dataTransfer: {
+        dropEffect: 'copy',
+        files: [droppedFile],
+        types: ['Files'],
+      },
+    })
+
+    expect(screen.queryByText('dataset.newKnowledge.dropFilesHere')).not.toBeInTheDocument()
+    expect(await screen.findByText('handbook.md')).toBeInTheDocument()
+  })
+
   it('keeps direct-upload actions unavailable until the deployment is verified', () => {
     systemFeaturesStateMock.uploadEnabled = false
 

web/features/new-rag/document-list.tsx

@@ -921,7 +921,7 @@ export function DocumentDropOverlay() {
       className="pointer-events-none absolute inset-0 z-30 flex flex-col items-center justify-center rounded-lg border-2 border-dashed border-divider-regular bg-[rgba(255,255,255,0.5)] text-center backdrop-blur-[5px]"
       role="status"
     >
-      <div className="flex w-57 items-center justify-center gap-5 rounded-xl border border-dashed border-divider-regular bg-components-panel-bg px-8 py-7 shadow-xs">
+      <div className="flex h-22 w-57 items-center justify-center gap-2 rounded-xl border border-dashed border-divider-regular bg-components-panel-bg shadow-xs">
         <span aria-hidden className="i-ri-file-word-2-fill size-6 text-text-accent" />
         <span aria-hidden className="i-ri-file-pdf-2-fill size-6 text-text-destructive" />
         <span aria-hidden className="i-ri-file-excel-fill size-6 text-text-success" />
@@ -930,7 +930,7 @@ export function DocumentDropOverlay() {
       <p className="mt-4 system-md-semibold text-text-primary">
         {t(($) => $['newKnowledge.dropFilesHere'])}
       </p>
-      <p className="mt-2 system-xs-regular text-text-tertiary">
+      <p className="mt-1 system-xs-regular text-text-tertiary">
         {t(($) => $['newKnowledge.documentUploadFormats'])}
       </p>
     </div>

web/features/new-rag/document-upload-form.tsx

@@ -1,8 +1,9 @@
 'use client'
 
+import type { Ref } from 'react'
 import type { KnowledgeFsUploadPhase } from './knowledge-fs-upload'
 import { Button } from '@langgenius/dify-ui/button'
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { useCallback, useEffect, useImperativeHandle, useMemo, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 import { DocumentUploadFileList } from './document-upload-file-list'
 import {
@@ -12,6 +13,21 @@ import {
   uniqueDocumentUploadFiles,
 } from './document-upload-policy'
 
+export type DocumentUploadFormHandle = {
+  addFiles: (files: File[]) => void
+}
+
+type DocumentUploadFormProps = {
+  initialFiles?: File[]
+  onCancel: () => void
+  onFilesAdded: (files: File[]) => Promise<void>
+  onFileRemoved: (file: File) => void
+  onSubmit: (files: File[]) => Promise<boolean>
+  uploadProgress?: ReadonlyMap<File, KnowledgeFsUploadPhase>
+  uploading: boolean
+  ref?: Ref<DocumentUploadFormHandle>
+}
+
 export function DocumentUploadForm({
   initialFiles = [],
   onCancel,
@@ -20,15 +36,8 @@ export function DocumentUploadForm({
   onSubmit,
   uploadProgress = new Map(),
   uploading,
-}: {
-  initialFiles?: File[]
-  onCancel: () => void
-  onFilesAdded: (files: File[]) => Promise<void>
-  onFileRemoved: (file: File) => void
-  onSubmit: (files: File[]) => Promise<boolean>
-  uploadProgress?: ReadonlyMap<File, KnowledgeFsUploadPhase>
-  uploading: boolean
-}) {
+  ref,
+}: DocumentUploadFormProps) {
   const { t } = useTranslation('dataset')
   const { t: tCommon } = useTranslation('common')
   const inputRef = useRef<HTMLInputElement>(null)
@@ -62,6 +71,19 @@ export function DocumentUploadForm({
     [onFilesAdded],
   )
 
+  const addFiles = useCallback(
+    (nextFiles: File[]) => {
+      const uniqueFiles = uniqueDocumentUploadFiles(filesRef.current, nextFiles)
+      const validUniqueFiles = uniqueFiles.filter((file) => !documentUploadIssue(file))
+      filesRef.current = [...filesRef.current, ...uniqueFiles]
+      setFiles(filesRef.current)
+      stageAddedFiles(validUniqueFiles)
+    },
+    [stageAddedFiles],
+  )
+
+  useImperativeHandle(ref, () => ({ addFiles }), [addFiles])
+
   useEffect(() => {
     if (initialFilesAnnouncedRef.current) return
     initialFilesAnnouncedRef.current = true
@@ -78,14 +100,6 @@ export function DocumentUploadForm({
       })
   }, [initialFiles, onFilesAdded])
 
-  const addFiles = (nextFiles: File[]) => {
-    const uniqueFiles = uniqueDocumentUploadFiles(filesRef.current, nextFiles)
-    const validUniqueFiles = uniqueFiles.filter((file) => !documentUploadIssue(file))
-    filesRef.current = [...filesRef.current, ...uniqueFiles]
-    setFiles(filesRef.current)
-    stageAddedFiles(validUniqueFiles)
-  }
-
   return (
     <form
       aria-labelledby="new-knowledge-documents-title"

web/features/new-rag/documents-page.tsx

@@ -2,6 +2,7 @@
 
 import type { DocumentAction } from './document-actions-dropdown'
 import type { DocumentProcessingTask } from './document-models'
+import type { DocumentUploadFormHandle } from './document-upload-form'
 import type { DocumentUploadIssue } from './document-upload-policy'
 import type { KnowledgeFsUploadPhase, KnowledgeFsUploadProgress } from './knowledge-fs-upload'
 import type {
@@ -299,6 +300,7 @@ export function DocumentsPage({ knowledgeSpaceId }: { knowledgeSpaceId: string }
   )
   const [selectedDocumentIds, setSelectedDocumentIds] = useState<Set<string>>(() => new Set())
   const [uploadFormInitialFiles, setUploadFormInitialFiles] = useState<File[]>([])
+  const uploadFormRef = useRef<DocumentUploadFormHandle>(null)
   const [isFileDragActive, setIsFileDragActive] = useState(false)
   const fileDragDepthRef = useRef(0)
   const [tasksOpen, setTasksOpen] = useState(false)
@@ -2594,7 +2596,7 @@ export function DocumentsPage({ knowledgeSpaceId }: { knowledgeSpaceId: string }
           const types = Array.from(event.dataTransfer.types ?? [])
           if (types.length && !types.includes('Files')) return
           event.preventDefault()
-          if (!canUpload || uploadFormOpen || uploading) return
+          if (!canUpload || uploading) return
           fileDragDepthRef.current += 1
           setIsFileDragActive(true)
         }}
@@ -2607,8 +2609,7 @@ export function DocumentsPage({ knowledgeSpaceId }: { knowledgeSpaceId: string }
           const types = Array.from(event.dataTransfer.types ?? [])
           if (types.length && !types.includes('Files')) return
           event.preventDefault()
-          if (!uploadFormOpen)
-            event.dataTransfer.dropEffect = canUpload && !uploading ? 'copy' : 'none'
+          event.dataTransfer.dropEffect = canUpload && !uploading ? 'copy' : 'none'
         }}
         onDrop={(event) => {
           const types = Array.from(event.dataTransfer.types ?? [])
@@ -2616,9 +2617,11 @@ export function DocumentsPage({ knowledgeSpaceId }: { knowledgeSpaceId: string }
           event.preventDefault()
           fileDragDepthRef.current = 0
           setIsFileDragActive(false)
-          if (!canUpload || uploadFormOpen || uploading) return
+          if (!canUpload || uploading) return
           const files = [...event.dataTransfer.files]
-          if (files.length) openUploadForm(files)
+          if (!files.length) return
+          if (uploadFormOpen) uploadFormRef.current?.addFiles(files)
+          else openUploadForm(files)
         }}
         onBlurCapture={(event) => {
           if (!event.currentTarget.contains(event.relatedTarget as Node | null)) {
@@ -2860,6 +2863,7 @@ export function DocumentsPage({ knowledgeSpaceId }: { knowledgeSpaceId: string }
           </div>
         ) : uploadFormOpen ? (
           <DocumentUploadForm
+            ref={uploadFormRef}
             initialFiles={uploadFormInitialFiles}
             uploadProgress={stagedUploadProgress}
             uploading={uploading}
@@ -2952,7 +2956,7 @@ export function DocumentsPage({ knowledgeSpaceId }: { knowledgeSpaceId: string }
             uploading={uploading}
           />
         )}
-        {isFileDragActive && canUpload && !uploadFormOpen && <DocumentDropOverlay />}
+        {isFileDragActive && canUpload && <DocumentDropOverlay />}
       </section>
       {bulkActionsVisible && (
         <DocumentBulkActions