This article explains why global error capture for XHR and Fetch requests is essential, shows how to intercept and report those errors, demonstrates injecting B3 trace headers for end‑to‑end tracing, and provides practical solutions for cross‑origin scenarios.
Front‑end monitoring must capture JavaScript runtime errors, resource loading failures, unhandled promise rejections, and asynchronous request issues using window.onerror, error event listeners, unhandledrejection handlers, and fetch/XHR wrappers, while also handling framework‑specific hooks and cross‑origin script restrictions through CORS or manual try‑catch reporting.
This tutorial explains how to build a robust front‑end image‑upload component for identity verification that works across modern and legacy browsers, leverages Ajax/XHR with FormData, shows progress handling, solves cross‑origin issues with CORS, and provides a Flash fallback for older IE versions.
This guide explains the different form enctype types, dissects a multipart/form-data example, outlines the encoding rules, and provides step‑by‑step JavaScript and Node.js code for manually constructing and sending such requests, including handling of text fields and binary files.
