Document low-code export options

docs/en/low-code/index.md

@@ -110,7 +110,13 @@ React low-code filters are type-aware. The runtime shows only operators that mak
 
 ## Export
 
-Every dynamic entity page can export filtered data to Excel or CSV. Export requests use the same search, sorting, and filter input as the list endpoint. Server-only fields are excluded and foreign key values are displayed through their configured display property.
+Every dynamic entity page can export data to Excel or CSV. Export requests use the current search, sorting, and filters from the runtime view, so a filtered page exports the matching subset instead of the whole entity.
+
+The React runtime exports visible columns by default. These columns come from the page fields configured in the Low-Code Designer, so changing a page's visible fields also changes the quick export output. Users can open **Export options** to switch to all exportable fields or to export only the current page of rows. Server-only fields are always excluded, and foreign key values are displayed through their configured display property.
+
+File and image fields are exported as file names by default. Export options can expand those fields into metadata columns or include small files as `data:<content-type>;base64,...` values. The data URL option is intended for small files only; files over the configured `LowCode:Export:MaxDataUrlFileSizeBytes` limit are skipped with a marker instead of failing the whole export.
+
+Export downloads require a short-lived, single-use token. The token is bound to the tenant, page, entity, child page, and foreign-access context. Spreadsheet formula-like text values are escaped before writing CSV or Excel cells.
 
 | Endpoint | Description |
 |----------|-------------|
@@ -118,6 +124,14 @@ Every dynamic entity page can export filtered data to Excel or CSV. Export reque
 | `GET /api/low-code/pages/{pageName}/export/excel` | Exports filtered data as Excel |
 | `GET /api/low-code/pages/{pageName}/export/csv` | Exports filtered data as CSV |
 
+Useful export settings:
+
+| Setting | Default | Purpose |
+|---------|---------|---------|
+| `LowCode:Export:MaxRows` | `100000` | Maximum rows in one all-filtered export |
+| `LowCode:Export:DownloadTokenLifetimeSeconds` | `30` | Download token lifetime |
+| `LowCode:Export:MaxDataUrlFileSizeBytes` | `16384` | Maximum file size for data URL export |
+
 ## Advanced Configuration
 
 The designer stores and reads the same model metadata described in the reference pages below. Use these pages when you need source-controlled model files, custom startup wiring, script handlers, or low-level integration details.

docs/en/low-code/react-runtime.md

@@ -151,7 +151,21 @@ The URL keeps the existing `lcFilters` query parameter shape. The runtime maps u
 
 ## Export
 
-The runtime export button requests a download token and then calls the Excel or CSV export endpoint with the current search, sorting, and filters.
+The runtime export button opens a small menu with direct Excel and CSV actions. Direct export uses the current search, sorting, filters, and visible columns from the page definition maintained in the Low-Code Designer. Use **Export options** when users need a different row or column scope.
+
+Available options:
+
+| Option | Behavior |
+|--------|----------|
+| Rows: all matching records | Exports all records matching the current search, filters, and sorting |
+| Rows: current page | Exports only the current page using the runtime `skipCount` and `maxResultCount` |
+| Columns: visible columns | Exports the columns visible in the current page definition |
+| Columns: all exportable fields | Exports all non-server-only fields that can appear in generated views |
+| File/image: file name | Writes the uploaded file name, or an empty value |
+| File/image: metadata columns | Writes file name, content type, size, width, and height columns |
+| File/image: data URL | Writes small linked files as `data:<content-type>;base64,...`; large or unavailable files are written as markers |
+
+The runtime first requests a short-lived token and then calls the Excel or CSV export endpoint. The token is single-use and is bound to the current page, entity, tenant, child page, and foreign-access context. Text that looks like a spreadsheet formula is escaped in exported cells.
 
 | Endpoint | Description |
 |----------|-------------|
@@ -161,6 +175,14 @@ The runtime export button requests a download token and then calls the Excel or
 
 Child and foreign-access pages use the matching `/children/{childEntityName}` and `/foreign-access/{sourceEntityName}` page endpoints.
 
+Troubleshooting:
+
+| Symptom | Likely cause |
+|---------|--------------|
+| Invalid or expired download token | The token is single-use, expired, or was requested for a different page/context |
+| Export row limit exceeded | Narrow the filters, export the current page, or increase `LowCode:Export:MaxRows` |
+| File not exported marker | The file was missing, too large for data URL export, malformed, or no longer linked to the exported record |
+
 ## Files and Attachments
 
 File and image fields use the page file endpoints. Record-level attachments use attachment endpoints when attachments are enabled for the entity.