Angular Input File Upload: Count Requests Before Trusting Progress

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<html lang="en-US"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>Angular Input File Upload: Count Requests Before Trusting Progress</title><style>:root{--bg:#edf1f5;--paper:#fff;--ink:#193449;--accent:#245d86;--tint:#dfeaf2;--line:#c4d0da;--muted:#40586a;--button:#fff}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:17px/1.55 system-ui,sans-serif}main{max-width:1000px;margin:auto;padding:22px clamp(18px,4vw,42px) 38px}header{border-bottom:2px solid var(--accent);padding-bottom:14px;margin-bottom:18px}h1{font-size:clamp(26px,4vw,36px);line-height:1.15;margin:4px 0 10px}h2{font-size:22px;line-height:1.3;margin:0 0 14px}h3{font-size:19px}p{margin:0 0 14px}.eyebrow{font-size:16px;font-weight:750;color:var(--accent)}.lede{max-width:800px}.panel{background:var(--paper);border:1px solid var(--line);border-radius:9px;padding:20px;margin:18px 0}.workbench{border-top:4px solid var(--accent)}.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.grid>*{min-width:0}label{display:block;font-size:16px;font-weight:650;margin:12px 0 6px}input,textarea,select{font:inherit;color:var(--ink);background:var(--paper);border:1px solid #7b8893;border-radius:5px;padding:10px;width:100%;min-width:0}textarea{resize:vertical;line-height:1.45}input[type=checkbox],input[type=radio]{width:21px;height:21px;vertical-align:middle;margin-right:9px}button{font:650 16px/1.4 system-ui,sans-serif;padding:11px 15px;min-height:46px;background:var(--accent);border:2px solid var(--accent);color:var(--button);border-radius:5px;cursor:pointer}button:disabled{opacity:.55;cursor:default}.buttons{display:flex;gap:9px;flex-wrap:wrap;margin:14px 0}.buttons>*{flex:1 1 auto}button:focus-visible,input:focus-visible,textarea:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #c05b00;outline-offset:3px}.result{font:600 17px/1.6 ui-monospace,monospace;white-space:pre-wrap;overflow-wrap:anywhere;background:var(--tint);padding:16px;border-left:4px solid var(--accent);min-height:65px;margin:16px 0}.sample{padding:14px 16px;border-left:3px solid var(--accent);background:var(--tint);margin:12px 0}.muted{color:var(--muted)}pre,code{font:16px/1.6 ui-monospace,monospace;white-space:pre-wrap;overflow-wrap:anywhere}pre{margin:12px 0}table{border-collapse:collapse;width:100%;table-layout:fixed;font-size:16px}th,td{text-align:left;vertical-align:top;padding:10px 8px;border-bottom:1px solid var(--line);overflow-wrap:anywhere}th{background:var(--tint)}svg{max-width:100%;height:auto;display:block}details{margin:20px 0}summary{font-weight:700;cursor:pointer}footer{margin-top:28px;border-top:1px solid var(--line);padding-top:18px;font-size:16px}a{color:var(--accent)}.reading{font-family:Georgia,serif}.codeview{border-radius:0;box-shadow:7px 7px 0 var(--tint)}.token{display:inline-block;padding:8px 12px;margin:4px;border:1px solid var(--line);border-radius:4px;background:var(--paper)}.swatch{min-height:30px}.split{display:grid;grid-template-columns:1.1fr 1fr;gap:22px}ol{padding-left:25px}li{margin:9px 0}@media(max-width:600px){main{padding:16px}.grid,.split{grid-template-columns:1fr}.panel{padding:16px;margin:14px 0}h1{font-size:27px}header{padding-bottom:10px}.buttons{gap:8px}.result{padding:13px}th,td{padding:8px 5px}}</style></head><body><main><header><div class="eyebrow">Original practice fixture · local workbench</div><h1>Count subscriptions before trusting progress</h1><p class="lede">Synthetic demo.txt contains 0123456789, ten payload bytes; FormData field file; POST /demo-upload. Zero, one, or two subscriptions imply zero, one, or two expected intercepted requests. Progress 5/10 = 50%. Headers do not establish acceptance. The final body requires accepted === true and a nonblank string id.</p></header><pre id="result" class="result" role="status" aria-live="polite" aria-atomic="true">Authored mock event: 5/10 → 50%; final acceptance still pending.</pre><label for="subscriptions">Subscriptions to inspect</label><input id="subscriptions" value="1" ><div class="buttons"><button type="button" id="count">Calculate expected requests</button></div><label for="loaded">Mock loaded bytes</label><input id="loaded" value="5" ><label for="total">Mock total · blank means unknown</label><input id="total" value="10" ><label for="body">Mock final JSON body</label><textarea id="body" rows="3" >{&quot;accepted&quot;:true,&quot;id&quot;:&quot;demo-01&quot;}</textarea><div class="buttons"><button type="button" id="progress">Progress event</button><button type="button" id="header">Header event</button><button type="button" id="response">Final response</button><button type="button" id="error">HTTP 400 case</button></div><section class="panel"><h2>Native fixture</h2><p>POST /demo-upload, FormData field file, ten-byte synthetic payload. Native Angular transport/version/testing must be checked separately.</p></section><footer><p>This is a local acceptance-contract inspector, not Angular Observable execution, an actual upload, network progress, or server storage.</p><p>Use a prepared HTML explanation in <a href="https://nos-workspace.com/">NOS</a> when reviewing this request-count and event-contract inspector. Eligible static instructions can be revised in visual editing mode; dynamic outputs follow their controls.</p></footer></main><script>
(()=>{'use strict';const $=s=>document.querySelector(s);const out=s=>{$('#result').textContent=s;};const val=id=>$('#'+id).value;const num=id=>{const s=val(id).trim();return s===''?NaN:Number(s);};const on=(id,fn)=>$('#'+id).addEventListener('click',fn);const watch=ids=>{for(const id of ids)for(const event of ['input','change'])$('#'+id).addEventListener(event,()=>out('Inputs changed. Run the action to update this result.'));};const fmt=(n,d=4)=>Math.abs(n)<1e-10?(0).toFixed(d):n.toFixed(d);
(function(){watch(['subscriptions','loaded','total','body']);on('count',()=>{const n=num('subscriptions');out(Number.isInteger(n)&&n>=0&&n<=10?'Expected intercepted requests: '+n+'. One per subscription; native test not run.':'Invalid subscription count: integer 0–10 required.');});on('progress',()=>{const loaded=num('loaded'),total=num('total');if(!Number.isFinite(loaded)||loaded<0){out('Invalid loaded count.');return;}if(val('total').trim()===''){out('Mock progress: '+loaded+' bytes loaded; indeterminate total. Acceptance pending.');return;}if(!Number.isFinite(total)||total<=0||loaded>total){out('Invalid progress denominator/count.');return;}out('Mock progress: '+fmt(loaded/total*100,2)+'%. Acceptance pending.');});on('header',()=>out('Mock ResponseHeader: headers received; final-body acceptance pending.'));on('response',()=>{let b;try{b=JSON.parse(val('body'));}catch{out('Invalid JSON body. No acceptance.');return;}out(b&&b.accepted===true&&typeof b.id==='string'&&b.id.trim()?'Mock final body accepted under this contract; id '+b.id+'. No real upload performed.':'Mock HTTP 200 body invalid: accepted must be true and id a nonblank string.');});on('error',()=>out('Mock HTTP 400: error. No acceptance or automatic resend.'));})();
})();
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