From 32f1324e304de72085f56e817290a41d285cc6e0 Mon Sep 17 00:00:00 2001
From: SheetJS <dev@sheetjs.com>
Date: Tue, 18 Oct 2022 03:55:41 -0400
Subject: [PATCH] clipboard files

---
 docz/docs/03-demos/32-clipboard.md | 112 ++++++++++++++++++++---------
 1 file changed, 77 insertions(+), 35 deletions(-)

diff --git a/docz/docs/03-demos/32-clipboard.md b/docz/docs/03-demos/32-clipboard.md
index 951f294..28084da 100644
--- a/docz/docs/03-demos/32-clipboard.md
+++ b/docz/docs/03-demos/32-clipboard.md
@@ -43,37 +43,81 @@ Open a file in Excel, copy some cells, then come back to this window.  Click on
 "RESULT" below and paste (Control+V for Windows, Command+V for Mac).
 
 ```jsx live
-function Clipboard() {
+function ClipboardRead() {
   const [csvs, setCSVs] = React.useState([ "", "", "" ]);
 
   /* Set up paste handler */
-  React.useEffect(async() => {
-    document.onpaste = function(e) {
-      /* this demo will read 3 different clipboard data types */
-      var mime_arr = [ 'text/plain', 'text/html', 'text/rtf' ];
-      /* get clipboard data for each type */
-      var data_arr = mime_arr.map(mime => e.clipboardData.getData(mime));
-      /* parse each data string into a workbook */
-      var wb_arr = data_arr.map(str => XLSX.read(str, {type: "string"}));
-      /* get first worksheet from each workbook */
-      var ws_arr = wb_arr.map(wb => wb.Sheets[wb.SheetNames[0]]);
-      /* generate CSV for each "first worksheet" */
-      var result = ws_arr.map(ws => XLSX.utils.sheet_to_csv(ws));
-      setCSVs(result);
-    };
+  const paste = React.useCallback((e) => {
+    /* this demo will read 3 different clipboard data types */
+    var mime_arr = [ 'text/plain', 'text/html', 'text/rtf' ];
+    /* get clipboard data for each type */
+    var data_arr = mime_arr.map(mime => e.clipboardData.getData(mime));
+    /* parse each data string into a workbook */
+    var wb_arr = data_arr.map(str => XLSX.read(str, {type: "string"}));
+    /* get first worksheet from each workbook */
+    var ws_arr = wb_arr.map(wb => wb.Sheets[wb.SheetNames[0]]);
+    /* generate CSV for each "first worksheet" */
+    var result = ws_arr.map(ws => XLSX.utils.sheet_to_csv(ws));
+    setCSVs(result);
   }, []);
 
-  return (
-    <>
+  return ( <>
       {csvs[0] && (<pre><b>Data from clipboard TSV  (text/plain)</b><br/>{csvs[0]}</pre>)}
       {csvs[1] && (<pre><b>Data from clipboard HTML (text/html)</b><br/>{csvs[1]}</pre>)}
       {csvs[2] && (<pre><b>Data from clipboard RTF  (text/rtf)</b><br/>{csvs[2]}</pre>)}
-      {csvs.every(x => !x) && <b>Copy data in Excel, click here, and paste (Control+V)</b>}
-    </>
-  );
+      {csvs.every(x => !x) && <b onPaste={paste}>Copy data in Excel, click here, and paste (Control+V)</b>}
+  </> );
 }
 ```
 
+### Reading Files
+
+Modern browsers support reading files that users have copied into the clipboard.
+
+:::caution
+
+Excel does not copy data into files! Use your system file browser to select and
+copy spreadsheets into the clipboard.
+
+:::
+
+The event `clipboardData.files` property, if it is set, is a list of files.
+
+```jsx live
+function ClipboardReadFiles() {
+  const [data, setData] = React.useState([]);
+
+  /* Set up paste handler */
+  const paste = React.useCallback(async(e)=>{
+    const result = [];
+
+    /* loop over files */
+    const files = e.clipboardData.files || [];
+    for(let i = 0; i < files.length; ++i) {
+      const file = files.item(i);
+
+      /* filter MIME type for spreadsheets */
+      if(!file.type.match(/excel|sheet|csv/)) continue;
+
+      /* read data */
+      const wb = XLSX.read(await file.arrayBuffer());
+
+      /* capture sheet names */
+      result.push([file.name, wb.SheetNames]);
+    }
+    setData(result);
+  }, []);
+
+  return ( <>
+    {data.map((f,idx) => (<pre key={idx}>
+      <b>Sheet Names from {f[0]}</b><br/>{f[1].join("\n")}
+    </pre>))}
+    {!data.length && (<b onPaste={paste}>Copy files, click here, and paste (Control+V)</b>)}
+  </> );
+}
+```
+
+
 ## Browser Writing (copy)
 
 Clipboard data can be written from a `copy` event, accessible from the event
@@ -104,34 +148,32 @@ Browsers do not currently support assigning to the `text/rtf` clipboard type.
 
 This demo creates a simple workbook from the following HTML table:
 
-<table id="srcdata">
+<table id="srcdata"><tbody>
   <tr><td>SheetJS</td><td>Clipboard</td><td>Demo</td></tr>
   <tr><td>bookType</td><td>RTF</td></tr>
   <tr><td>source</td><td>HTML Table</td></tr>
-</table>
+</tbody></table>
 
 Create a new file in Excel then come back to this window.  Select the text
 below and copy (Control+C for Windows, Command+C for Mac).  Go back to the
 excel
 
 ```jsx live
-function Clipboard() {
+function ClipboardWrite() {
   /* Set up copy handler */
-  React.useEffect(async() => {
-    document.oncopy = function(e) {
-      /* generate workbook from table */
-      var wb = XLSX.utils.table_to_book(document.getElementById("srcdata"));
-      /* get HTML of first worksheet in workbook */
-      var str = XLSX.write(wb, {type: "string", bookType: "html"});
-      /* set HTML clipboard data */
-      e.clipboardData.setData('text/html', str);
-      /* prevent the browser from copying the normal data */
-      e.preventDefault();
-    };
+  const copy = React.useCallback((e) => {
+    /* generate workbook from table */
+    var wb = XLSX.utils.table_to_book(document.getElementById("srcdata"));
+    /* get HTML of first worksheet in workbook */
+    var str = XLSX.write(wb, {type: "string", bookType: "html"});
+    /* set HTML clipboard data */
+    e.clipboardData.setData('text/html', str);
+    /* prevent the browser from copying the normal data */
+    e.preventDefault();
   }, []);
 
   return (
-    <b>Select this text, copy (Control+C), and paste in Excel</b>
+    <b onCopy={copy}>Select this text, copy (Control+C), and paste in Excel</b>
   );
 }
 ```