feat(app builder): adding downloadFile frontend helper

frontend/src/lib/components/apps/components/helpers/RunnableWrapper.svelte

@@ -31,6 +31,7 @@
 					| 'open'
 					| 'close'
 					| 'clearFiles'
+					| 'downloadFile'
 				configuration: {
 					gotoUrl: { url: (() => string) | string | undefined; newTab: boolean | undefined }
 					setTab: {
@@ -61,6 +62,10 @@
 					clearFiles?: {
 						id: string | undefined
 					}
+					downloadFile?: {
+						id: string | undefined
+						fileName: string | undefined
+					}
 				}
 		  }
 		| undefined
@@ -235,6 +240,15 @@
 				$componentControl[id].clearFiles?.()
 				break
 			}
+			case 'downloadFile': {
+				const id = sideEffect?.configuration?.downloadFile?.id
+				const fileName = sideEffect?.configuration?.downloadFile?.fileName
+
+				if (!id || !fileName) return
+
+				$componentControl[id].downloadFile?.(fileName)
+				break
+			}
 			default:
 				break
 		}

frontend/src/lib/components/apps/components/helpers/eval.ts

@@ -25,7 +25,7 @@ function create_context_function_template(
 ) {
 	let hasReturnAsLastLine = noReturn || eval_string.split('\n').some((x) => x.startsWith('return '))
 	return `
-return async function (context, state, createProxy, goto, setTab, recompute, getAgGrid, setValue, setSelectedIndex, openModal, closeModal, open, close, validate, invalidate, validateAll, clearFiles, showToast, waitJob, askNewResource) {
+return async function (context, state, createProxy, goto, setTab, recompute, getAgGrid, setValue, setSelectedIndex, openModal, closeModal, open, close, validate, invalidate, validateAll, clearFiles, downloadFile, showToast, waitJob, askNewResource) {
 "use strict";
 ${
 	contextKeys && contextKeys.length > 0
@@ -61,6 +61,7 @@ type WmFunctor = (
 	invalidate,
 	validateAll,
 	clearFiles,
+	downloadFile,
 	showToast,
 	waitJob,
 	askNewResource
@@ -111,6 +112,7 @@ export async function eval_like(
 			invalidate?: (key: string, error: string) => void
 			validateAll?: () => void
 			clearFiles?: () => void
+			downloadFile?: (fileName: string) => void
 			showToast?: (message: string, error?: boolean) => void
 			waitJob?: (jobId: string) => void
 			askNewResource?: () => void
@@ -231,6 +233,9 @@ export async function eval_like(
 		(id) => {
 			controlComponents[id]?.clearFiles?.()
 		},
+		(id, fileName) => {
+			controlComponents[id]?.downloadFile?.(fileName)
+		},
 		(message, error) => {
 			sendUserToast(message, error)
 		},

frontend/src/lib/components/apps/components/inputs/AppFileInput.svelte

@@ -48,6 +48,9 @@
 	$componentControl[id] = {
 		clearFiles: () => {
 			fileInput?.clearFiles()
+		},
+		downloadFile: (fileName: string) => {
+			fileInput?.downloadFile(fileName)
 		}
 	}
 

frontend/src/lib/components/apps/types.ts

@@ -261,6 +261,7 @@ export type AppViewerContext = {
 				invalidate?: (key: string, error: string) => void
 				validateAll?: () => void
 				clearFiles?: () => void
+				downloadFile?: (fileName: string) => void
 				showToast?: (message: string, error?: boolean) => void
 				recompute?: () => void
 				askNewResource?: () => void

frontend/src/lib/components/apps/utils.ts

@@ -281,6 +281,12 @@ declare function validateAll(id: string): void;
  */
 declare function clearFiles(id: string): void;
 
+/** Download a file from a file input component
+ * @param id component's id
+ * @param fileName name of the file to download
+ */
+declare function downloadFile(id: string, fileName: string): void;
+
 /**  Display a toast message
  * @param message message to display
  */

frontend/src/lib/components/common/fileInput/FileInput.svelte

@@ -121,6 +121,31 @@
 		files = undefined
 		dispatchChange()
 	}
+
+	export function downloadFile(fileName: string) {
+		if (!files) {
+			console.error('Trying to download a file: No files uploaded');
+			return;
+		}
+		const file = files.find(f => f.name === fileName);
+		if (!file) {
+			console.error(`Trying to download a file: File "${fileName}" doesn't exist`);
+			return;
+		}
+
+		const url = URL.createObjectURL(file);
+		const a = document.createElement('a');
+		a.href = url;
+		a.download = fileName;
+		document.body.appendChild(a);
+		a.click();
+		document.body.removeChild(a);
+
+		// Delay revoking the object URL to ensure the download works
+		setTimeout(() => {
+			URL.revokeObjectURL(url);
+		}, 100);
+	}
 </script>
 
 <button