rewrote impose to use new Operator class,

dependencies (pdfcpu) can be made environment-aware using tsconfig.json

shared-operations/src/functions/impose.ts

@@ -1,6 +1,9 @@
 
 import { PdfFile, RepresentationType } from "../wrappers/PdfFile";
 import { FieldConstraint, RecordConstraint } from '../dynamic-ui/OperatorConstraints'
+import { IOType, Operator, Progress } from ".";
+
+import * as pdfcpuWrapper from "#pdfcpu"; // This is updated by tsconfig.json/paths for the context (browser, node, etc.) this module is used in.
 
 export type ImposeParamsType = {
     file: PdfFile;
@@ -10,36 +13,69 @@ export type ImposeParamsType = {
     format: string;
 }
 
+export class Impose extends Operator {
+    static type: string = "impose";
+
+    static mayInput: IOType = IOType.PDF;
+    static willOutput: IOType = IOType.PDF;
+
+    /** PDF-Imposition, PDF-N-Up: Put multiple pages of the input document into a single page of the output document. - see: {@link https://en.wikipedia.org/wiki/N-up}  */
+    async run(input: PdfFile[], progressCallback: (state: Progress) => void): Promise<PdfFile[]> {
+        return this.nToN<PdfFile, PdfFile>(input, async (input, index, max) => {
+            // https://pdfcpu.io/generate/nup.html
+            const uint8Array = await pdfcpuWrapper.oneToOne(
+                [
+                    "pdfcpu.wasm",
+                    "nup",
+                    "-c",
+                    "disable",
+                    'f:' + this.actionValues.format,
+                    "/output.pdf",
+                    String(this.actionValues.nup),
+                    "input.pdf",
+                ],
+                await input.uint8Array
+            );
+
+            const result = new PdfFile(
+                input.originalFilename,
+                uint8Array,
+                RepresentationType.Uint8Array,
+                input.filename + "_imposed"
+            );
+
+            progressCallback({ curFileProgress: 1, operationProgress: index/max })
+            
+            console.log("ImposeResult: ", result);
+            return [result];
+        })
+    }
+
+    validate(): { valid: boolean; reason?: string | undefined; } {
+        let baseValidationResults = super.validate();
+        if(!baseValidationResults.valid)
+            return baseValidationResults;
+
+        // TODO: This should be ported to SaudF's RecordValidator
+        if(this.actionValues.nup) {
+            if(![2, 3, 4, 8, 9, 12, 16].includes(this.actionValues.nup)) {
+                return  { valid: false, reason: "NUp accepted values are 2, 3, 4, 8, 9, 12, 16 - see: https://pdfcpu.io/generate/nup.html#n-up-value"}
+            }
+        }
+        else
+            return { valid: false, reason: "nup is not defined" }
+
+        if(!this.actionValues.format) {
+            return { valid: false, reason: "format is not defined" }
+        }
+        // TODO: Format should be checked for all acceped formats
+
+        return { valid: true }
+    }
+}
+
 export const ImposeParamConstraints = new RecordConstraint({
     file: new FieldConstraint("display.key", "file.pdf", true, "hint.key"),
     nup: new FieldConstraint("display.key", [2, 3, 4, 8, 9, 12, 16], true, "hint.key"),
     format: new FieldConstraint("display.key", ["A0","A1","A2","A3","A4","A5","A6","A7","A8","A9","A10","Letter","Legal"], true, "hint.key"),
-})
-
-/** PDF-Imposition, PDF-N-Up: Put multiple pages of the input document into a single page of the output document. - see: {@link https://en.wikipedia.org/wiki/N-up}  */
-export async function impose(params: ImposeParamsType, pdfcpuWrapper: any): Promise<PdfFile> {
-    // https://pdfcpu.io/generate/nup.html
-    const uint8Array = await pdfcpuWrapper.oneToOne(
-        [
-            "pdfcpu.wasm",
-            "nup",
-            "-c",
-            "disable",
-            'f:' + params.format,
-            "/output.pdf",
-            String(params.nup),
-            "input.pdf",
-        ],
-        await params.file.uint8Array
-    );
-
-    const result = new PdfFile(
-        params.file.originalFilename,
-        uint8Array,
-        RepresentationType.Uint8Array,
-        params.file.filename + "_imposed"
-    );
-    
-    console.log("ImposeResult: ", result);
-    return result;
-}
+})