How do I make 2 (or more) calls with Adobe PDF Services and skip using the file system (in between?) - adobe-pdfservices

Question

It's fairly simple to make one call to Adobe PDF Services, get the result, and save it, for example:
// more stuff above
exportPdfOperation.execute(executionContext)
.then(result => result.saveAsFile(output))
But if I want to do two, or more, operations, do I need to keep saving the result to the file system and re-providing it (is that even a word ;) to the API?

Answer 1

So this tripped me up as well. In most demos, you'll see:
result => result.saveAsFile()
towards the end. However, the object passes to the completed promise, result, is a FileRef object that can then be used as the input to another call.
Here's a sample that takes an input Word doc and calls the API method to create a PDF. It then takes that and runs OCR on it. Both methods that wrap the API calls return FileRefs, so at the end I saveAsFile on it. (Note, this demo is using v1 of the SDK, it would work the same w/ v2.)
const PDFToolsSdk = require('#adobe/documentservices-pdftools-node-sdk');
const fs = require('fs');
//clean up previous
(async ()=> {
// hamlet.docx was too big for conversion
const input = './hamlet2.docx';
const output = './multi.pdf';
const creds = './pdftools-api-credentials.json';
if(fs.existsSync(output)) fs.unlinkSync(output);
let result = await createPDF(input, creds);
console.log('got a result');
result = await ocrPDF(result, creds);
console.log('got second result');
await result.saveAsFile(output);
})();
async function createPDF(source, creds) {
return new Promise((resolve, reject) => {
const credentials = PDFToolsSdk.Credentials
.serviceAccountCredentialsBuilder()
.fromFile(creds)
.build();
const executionContext = PDFToolsSdk.ExecutionContext.create(credentials),
createPdfOperation = PDFToolsSdk.CreatePDF.Operation.createNew();
// Set operation input from a source file
const input = PDFToolsSdk.FileRef.createFromLocalFile(source);
createPdfOperation.setInput(input);
let stream = new Stream.Writable();
stream.write = function() {
}
stream.end = function() {
console.log('end called');
resolve(stream);
}
// Execute the operation and Save the result to the specified location.
createPdfOperation.execute(executionContext)
.then(result => resolve(result))
.catch(err => {
if(err instanceof PDFToolsSdk.Error.ServiceApiError
|| err instanceof PDFToolsSdk.Error.ServiceUsageError) {
reject(err);
} else {
reject(err);
}
});
});
}
async function ocrPDF(source, creds) {
return new Promise((resolve, reject) => {
const credentials = PDFToolsSdk.Credentials
.serviceAccountCredentialsBuilder()
.fromFile(creds)
.build();
const executionContext = PDFToolsSdk.ExecutionContext.create(credentials),
ocrOperation = PDFToolsSdk.OCR.Operation.createNew();
// Set operation input from a source file.
//const input = PDFToolsSdk.FileRef.createFromStream(source);
ocrOperation.setInput(source);
let stream = new Stream.Writable();
stream.end = function() {
console.log('end called');
resolve(stream);
}
// Execute the operation and Save the result to the specified location.
ocrOperation.execute(executionContext)
.then(result => resolve(result))
.catch(err => reject(err));
});
}