b6fba9d66d
* Install the error handler early. * Include stack trace. * Remove unnecessary escaping. * Improve formatting. * Move to a separate script file.
48 lines
1.9 KiB
JavaScript
48 lines
1.9 KiB
JavaScript
// @license magnet:?xt=urn:btih:8e4f440f4c65981c5bf93c76d35135ba5064d8b7&dn=apache-2.0.txt Apache-2.0
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/* Copyright 2021 Richard Hansen <rhansen@rhansen.org> */
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'use strict';
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// Set up an error handler to display errors that happen during page load. This handler will be
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// overridden with a nicer handler by setupGlobalExceptionHandler() in pad_utils.js.
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(() => {
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const originalHandler = window.onerror;
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window.onerror = (...args) => {
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const [msg, url, line, col, err] = args;
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// Purge the existing HTML and styles for a consistent view.
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document.body.textContent = '';
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for (const el of document.querySelectorAll('head style, head link[rel="stylesheet"]')) {
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el.remove();
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}
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const box = document.body;
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box.textContent = '';
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const summary = document.createElement('p');
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box.appendChild(summary);
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summary.appendChild(document.createTextNode('An error occurred while loading the page:'));
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const msgBlock = document.createElement('blockquote');
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box.appendChild(msgBlock);
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msgBlock.style.fontWeight = 'bold';
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msgBlock.appendChild(document.createTextNode(msg));
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const loc = document.createElement('p');
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box.appendChild(loc);
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loc.appendChild(document.createTextNode(`in ${url}`));
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loc.appendChild(document.createElement('br'));
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loc.appendChild(document.createTextNode(`at line ${line}:${col}`));
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const stackSummary = document.createElement('p');
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box.appendChild(stackSummary);
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stackSummary.appendChild(document.createTextNode('Stack trace:'));
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const stackBlock = document.createElement('blockquote');
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box.appendChild(stackBlock);
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const stack = document.createElement('pre');
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stackBlock.appendChild(stack);
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stack.appendChild(document.createTextNode(err.stack || err.toString()));
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if (typeof originalHandler === 'function') originalHandler(...args);
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};
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})();
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// @license-end
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