WebAssembly

The page-validation-wasm npm package provides Wasm bindings for page.

Installation¶

npmpnpmyarn

npm install page-validation-wasm

pnpm add page-validation-wasm

yarn add page-validation-wasm

Check compliance of a PDF¶

isPdfCompliantBytes() is the fastest way to get a simple true/false compliance result for a profile. It expects the PDF as a Uint8Array:

import { isPdfCompliantBytes } from "page-validation-wasm";

const bytes = new Uint8Array(await pdfFile.arrayBuffer());
const isCompliant: boolean = await isPdfCompliantBytes(bytes);

If the profile isn't specified, it reads the PDF/A or PDF/UA profile declared in the document's XMP metadata. A missing, malformed, or unsupported profile declaration, or an input that cannot be read or parsed, throws ValidationError.

The first call initializes the WebAssembly module automatically. Call initialize() during application startup if you want to control initialization explicitly.

Validate a PDF with details¶

If you need details about which rules failed, use validatePdfBytes():

import { validatePdfBytes } from "page-validation-wasm";

const bytes = new Uint8Array(await pdfFile.arrayBuffer());
const report = await validatePdfBytes(bytes);

if (report.isCompliant) {
  console.log("The document passed all implemented checks.");
} else {
  for (const failure of report.failures) {
    console.log(`[${failure.ruleId}] ${failure.message}`);
  }
}

Select a profile explicitly¶

Pass a profile to validatePdfBytes() when the caller, rather than the document, selects it:

import { ValidationProfile, validatePdfBytes } from "page-validation-wasm";

const bytes = new Uint8Array(await pdfFile.arrayBuffer());
const report = await validatePdfBytes(bytes, ValidationProfile.PDF_A_1B);

The explicit-profile call does not require the document to contain a usable profile declaration. The declaration can still fail the selected profile's metadata rules. Use isPdfCompliantBytes() when you only need a boolean result.

Failures¶

Each report contains a list of failures:

import { validatePdfBytes } from "page-validation-wasm";

const report = await validatePdfBytes(bytes);

for (const failure of report.failures) {
  console.log(`Rule: ${failure.ruleId}`);
  console.log(`Category: ${failure.category}`);
  console.log(`Message: ${failure.message}`);
}

Failure categories distinguish conformance problems from parser or operational errors:

import { FailureCategory } from "page-validation-wasm";

for (const failure of report.failures) {
  if (
    failure.category === FailureCategory.METADATA ||
    failure.category === FailureCategory.CONFORMANCE
  ) {
    // The PDF was parsed, but failed a validation rule.
  } else if (failure.category === FailureCategory.PARSER) {
    // The PDF could not be parsed correctly.
  } else if (failure.category === FailureCategory.OPERATIONAL) {
    // Validation failed because of I/O or another runtime issue.
  }
}

Safety limits¶

Safety limits protect the validator from excessively large or complex inputs. Defaults are sufficient for most cases:

import { SafetyLimits, validatePdfBytes } from "page-validation-wasm";

const limits = new SafetyLimits({
  maxInputSize: 256 * 1024 * 1024, // 256 MiB
  maxDecodedStreamSize: 32 * 1024 * 1024, // 32 MiB
  maxTotalDecodedContentSize: 256 * 1024 * 1024, // 256 MiB
  maxObjectCount: 1_000_000, // 1,000,000 objects
  maxReferenceDepth: 256, // 256 levels
  maxXrefRevisions: 1_024, // 1,024 revisions
  maxTableSpan: 1_024, // rows or columns per cell
  maxTableGridRows: 1_024, // rows
  maxTableGridColumns: 1_024, // columns
  maxTableGridCells: 1_000_000, // cells
  maxUnicodeCmapMappings: 1_000_000, // mappings per ToUnicode CMap
});

const report = await validatePdfBytes(bytes, undefined, limits);

You can also pass a partial options object instead of constructing SafetyLimits. maxDecodedStreamSize bounds one decoded stream and maxTotalDecodedContentSize bounds the total decoded page, Form, appearance, Pattern, and Type3 content inspected for one document. maxXrefRevisions bounds the number of incremental-update revisions read from the cross-reference chain. maxTableSpan bounds the row or column span of an individual tagged-table cell. maxTableGridRows, maxTableGridColumns, and maxTableGridCells bound the derived table-grid dimensions and total cells. maxUnicodeCmapMappings bounds the total mappings expanded from one ToUnicode CMap.

Use the exit code¶

For automated checks, a report can provide an appropriate process exit code:

import { validatePdfBytes } from "page-validation-wasm";

const report = await validatePdfBytes(bytes);
process.exitCode = report.exitCode();

The exit code is 0 for a compliant report, 2 for a noncompliant report, and 1 when the report contains an operational failure.

Export the report¶

Validation reports can be exported as JSON:

import { validatePdfBytes } from "page-validation-wasm";

const report = await validatePdfBytes(bytes);
const json = report.toJson();