pvsundar CGPT Interactive HTML Export Hardening
Use this skill before building or repairing any single-file HTML artifact that lets the user edit in-browser and export JSON or a re-openable HTML file. Typical targets are dashboards, trackers, forms, configurators, and teaching tools.
Core Rules
- Treat JSON as canonical state and HTML as the interface. Provide both Export JSON and Import JSON.
- Never put a raw newline inside a single-quoted or double-quoted JavaScript string. Use
\nor template literals. - Call
applyStateToDOMForExport()beforecloneNode()orouterHTML. - Mirror runtime properties into attributes before serialization:
- checkboxes: set/remove
checked - selects: set
selectedon the chosen option only - ranges: set
valueand update adjacent output text - text inputs/textareas: set
value, and set textarea text content - contenteditable nodes: write
innerTextback totextContent
- checkboxes: set/remove
- Wrap export and download functions in
try/catch; log withconsole.errorand alert the user on failure. - Validate controlled dropdown values on load. If a stored value is not in the option set, map it through a legacy-value table, log a warning, and show a visible badge.
- Autosave on
inputandchangewith a short debounce. Reset local edits by clearing the artifact-specific localStorage key only. - Clearing localStorage must not erase state already preserved in exported HTML.
Required Pattern
function applyStateToDOMForExport(){
document.querySelectorAll('[data-field], [data-task]').forEach(el => {
if (el.type === 'checkbox') {
if (el.checked) el.setAttribute('checked', 'checked');
else el.removeAttribute('checked');
} else if (el.tagName === 'SELECT') {
el.querySelectorAll('option').forEach(opt => {
if (opt.value === el.value) opt.setAttribute('selected', 'selected');
else opt.removeAttribute('selected');
});
} else if (el.type === 'range') {
el.setAttribute('value', el.value);
const out = el.parentElement && el.parentElement.querySelector('output');
if (out) out.textContent = el.value + '%';
} else if (el.isContentEditable) {
el.textContent = el.innerText;
} else if (el.tagName === 'INPUT' || el.tagName === 'TEXTAREA') {
el.setAttribute('value', el.value);
if (el.tagName === 'TEXTAREA') el.textContent = el.value;
}
});
}
function exportHTML(){
try {
saveState();
applyStateToDOMForExport();
const clone = document.documentElement.cloneNode(true);
const html = '<!doctype html>\n' + clone.outerHTML;
download('artifact_EDITED.html', html, 'text/html;charset=utf-8');
} catch (err) {
console.error('Export HTML failed:', err);
alert('Export edited HTML failed. Open DevTools Console for details.');
}
}
function exportJSON(){
try {
const json = JSON.stringify(collect(), null, 2);
download('artifact_STATE.json', json, 'application/json;charset=utf-8');
} catch (err) {
console.error('Export JSON failed:', err);
alert('Export JSON failed. Open DevTools Console for details.');
}
}
function download(name, content, type){
try {
const blob = new Blob([content], { type: type || 'application/octet-stream' });
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.href = url;
a.download = name;
a.style.display = 'none';
document.body.appendChild(a);
a.click();
setTimeout(() => {
document.body.removeChild(a);
URL.revokeObjectURL(url);
}, 1000);
} catch (err) {
console.error('Download failed:', err);
alert('Download failed. Open DevTools Console for details.');
}
}
Validation
Before reporting done:
- Extract the inline script block and run
node --check. - Open the HTML from
file:///when practical and check the console. - Change a checkbox, select, range, and editable text field; export HTML; reopen in a fresh browser context; confirm all four changes persist.
- Export JSON, edit one field, import it, and verify the UI updates.
- Clear localStorage and reopen the exported HTML; preserved exported state should remain visible.
- Test an invalid dropdown value; the page should warn, map, and badge the affected card or control.