1 files changed, 71 insertions, 0 deletions
diff --git a/src_js/opcut/fs.js b/src_js/opcut/fs.js
new file mode 100644
index 0000000..b1d464e
--- /dev/null
+++ b/src_js/opcut/fs.js
@@ -0,0 +1,71 @@
+import h from 'hyperscript';
+import FileSaver from 'file-saver';
+
+import * as ev from 'opcut/ev';
+
+
+export function loadText(ext) {
+    const el = h('input', {
+        style: 'display: none',
+        type: 'file',
+        accept: ext});
+    const promise = new Promise(resolve => {
+        ev.on(el, 'change', evt => {
+            const file = u.get(['files', 0], evt.target);
+            if (!file)
+                return;
+            const fileReader = new FileReader();
+            fileReader.onload = () => {
+                const data = fileReader.result;
+                resolve(data);
+            };
+            fileReader.readAsText(file);
+        });
+        el.click();
+    });
+    return promise;
+}
+
+
+export function saveText(text, fileName) {
+    const blob = stringToBlob(text);
+    FileSaver.saveAs(blob, fileName);
+}
+
+
+export function saveB64Data(b64Data, fileName) {
+    const blob = b64ToBlob(b64Data);
+    FileSaver.saveAs(blob, fileName);
+}
+
+
+function stringToBlob(strData, contentType) {
+    contentType = contentType || '';
+    return new Blob([strData], {type: contentType});
+}
+
+
+// http://stackoverflow.com/a/16245768
+function b64ToBlob(b64Data, contentType, sliceSize) {
+    contentType = contentType || '';
+    sliceSize = sliceSize || 512;
+
+    var byteCharacters = atob(b64Data);
+    var byteArrays = [];
+
+    for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
+        var slice = byteCharacters.slice(offset, offset + sliceSize);
+
+        var byteNumbers = new Array(slice.length);
+        for (var i = 0; i < slice.length; i++) {
+            byteNumbers[i] = slice.charCodeAt(i);
+        }
+
+        var byteArray = new Uint8Array(byteNumbers);
+
+        byteArrays.push(byteArray);
+    }
+
+    var blob = new Blob(byteArrays, {type: contentType});
+    return blob;
+}