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Add page reload when resuming Blazor circuit fails #64290

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Add page reload when resuming Blazor circuit fails #64290

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fce8418
Add page reload when resuming Blazor circuit fails
oroztocil Nov 10, 2025
04ea8f0
Improve readability of DefaultReconnectDisplay
oroztocil Nov 12, 2025
a864856
Reload page automatically only when resume fails after non-graceful p…
oroztocil Nov 13, 2025
9cdfa5a
Use 'remote' flag to distinguish graceful and ungraceful circuit pauses
oroztocil Nov 17, 2025
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60 changes: 36 additions & 24 deletions src/Components/Web.JS/src/Platform/Circuits/DefaultReconnectDisplay.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -26,16 +26,18 @@ export class DefaultReconnectDisplay implements ReconnectDisplay {

rejoiningAnimation: HTMLDivElement;

reloadButton: HTMLButtonElement;
retryButton: HTMLButtonElement;

resumeButton: HTMLButtonElement;

status: HTMLParagraphElement;

reconnect = true;
operation: ReconnectDisplayUpdateOptions['type'] = 'reconnect';

remote = false;

graceful = false;

retryWhenDocumentBecomesVisible: () => void;

constructor(dialogId: string, private readonly document: Document, private readonly logger: Logger) {
Expand Down Expand Up @@ -65,10 +67,10 @@ export class DefaultReconnectDisplay implements ReconnectDisplay {
this.status = document.createElement('p');
this.status.innerHTML = '';

this.reloadButton = document.createElement('button');
this.reloadButton.style.display = 'none';
this.reloadButton.innerHTML = 'Retry';
this.reloadButton.addEventListener('click', this.retry.bind(this));
this.retryButton = document.createElement('button');
this.retryButton.style.display = 'none';
this.retryButton.innerHTML = 'Retry';
this.retryButton.addEventListener('click', this.retry.bind(this));

this.resumeButton = document.createElement('button');
this.resumeButton.style.display = 'none';
Expand All @@ -77,7 +79,7 @@ export class DefaultReconnectDisplay implements ReconnectDisplay {

this.dialog.appendChild(this.rejoiningAnimation);
this.dialog.appendChild(this.status);
this.dialog.appendChild(this.reloadButton);
this.dialog.appendChild(this.retryButton);
this.dialog.appendChild(this.resumeButton);

this.overlay.appendChild(this.dialog);
Expand All @@ -94,30 +96,33 @@ export class DefaultReconnectDisplay implements ReconnectDisplay {
this.document.body.appendChild(this.host);
}

this.reconnect = options?.type === 'reconnect';
this.operation = options?.type ?? 'reconnect';
this.graceful = (options?.type === 'pause') ? options.graceful : false;

this.reloadButton.style.display = 'none';
this.retryButton.style.display = 'none';
this.rejoiningAnimation.style.display = 'block';
this.status.innerHTML = 'Rejoining the server...';
this.host.style.display = 'block';
this.overlay.classList.add(DefaultReconnectDisplay.ReconnectVisibleClassName);
}

update(options: ReconnectDisplayUpdateOptions): void {
this.reconnect = options.type === 'reconnect';
if (this.reconnect) {
this.operation = options.type;
this.graceful = (options.type === 'pause') ? options.graceful : false;

if (this.operation === 'pause') {
this.retryButton.style.display = 'none';
this.rejoiningAnimation.style.display = 'none';
this.status.innerHTML = 'The session has been paused by the server.';
this.resumeButton.style.display = 'block';
} else {
const { currentAttempt, secondsToNextAttempt } = options as ReconnectOptions;
if (currentAttempt === 1 || secondsToNextAttempt === 0) {
this.status.innerHTML = 'Rejoining the server...';
} else {
const unitText = secondsToNextAttempt === 1 ? 'second' : 'seconds';
this.status.innerHTML = `Rejoin failed... trying again in ${secondsToNextAttempt} ${unitText}`;
}
} else {
this.reloadButton.style.display = 'none';
this.rejoiningAnimation.style.display = 'none';
this.status.innerHTML = 'The session has been paused by the server.';
this.resumeButton.style.display = 'block';
}
}

Expand All @@ -128,14 +133,21 @@ export class DefaultReconnectDisplay implements ReconnectDisplay {

failed(): void {
this.rejoiningAnimation.style.display = 'none';
if (this.reconnect) {
this.reloadButton.style.display = 'block';
if (this.operation === 'pause') {
if (this.graceful) {
// Circuit failed to resume after a graceful (client-requested) pause.
// We show a retry UI to allow the user to try to continue without losing the state.
this.resumeButton.style.display = 'block';
this.status.innerHTML = 'Failed to resume.<br />Please retry or reload the page.';
} else {
// Circuit failed to resume after an ungraceful pause (e.g., server restart).
// We treat this as non-recoverable rejection.
this.rejected();
}
} else {
this.retryButton.style.display = 'block';
this.status.innerHTML = 'Failed to rejoin.<br />Please retry or reload the page.';
this.document.addEventListener('visibilitychange', this.retryWhenDocumentBecomesVisible);
} else {
this.status.innerHTML = 'Failed to resume the session.<br />Please reload the page.';
this.resumeButton.style.display = 'none';
this.reloadButton.style.display = 'none';
}
}

Expand All @@ -157,10 +169,10 @@ export class DefaultReconnectDisplay implements ReconnectDisplay {
const successful = await Blazor.reconnect!();
if (!successful) {
// Try to resume the circuit if the reconnect failed
this.update({ type: 'pause', remote: this.remote });
this.update({ type: 'pause', remote: this.remote, graceful: this.graceful });
const resumeSuccessful = await Blazor.resumeCircuit!();
if (!resumeSuccessful) {
this.rejected();
this.failed();
}
}
} catch (err: unknown) {
Expand Down
4 changes: 3 additions & 1 deletion src/Components/Web.JS/src/Platform/Circuits/DefaultReconnectionHandler.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,7 @@ class ReconnectionProcess {
const displayOptions: ReconnectDisplayUpdateOptions = {
type: isGracefulPause ? 'pause' : 'reconnect',
remote: this.isRemote,
graceful: !!isGracefulPause,
currentAttempt: 0,
secondsToNextAttempt: 0,
};
Expand All @@ -85,6 +86,7 @@ class ReconnectionProcess {
this.reconnectDisplay.update({
type: 'pause',
remote: this.isRemote,
graceful: true,
});
}
}
Expand Down Expand Up @@ -126,7 +128,7 @@ class ReconnectionProcess {
if (!result) {
// Try to resume the circuit if the reconnect failed
// If the server responded and refused to reconnect, stop auto-retrying.
this.reconnectDisplay.update({ type: 'pause', remote: true });
this.reconnectDisplay.update({ type: 'pause', remote: true, graceful: false });
const resumeResult = await this.resumeCallback();
if (resumeResult) {
return;
Expand Down
3 changes: 2 additions & 1 deletion src/Components/Web.JS/src/Platform/Circuits/ReconnectDisplay.ts
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Expand Up @@ -13,7 +13,8 @@ export type ReconnectDisplayUpdateOptions = ReconnectOptions | PauseOptions;

export type PauseOptions = {
type: 'pause',
remote: boolean
remote: boolean,
graceful: boolean
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@javiercn javiercn Nov 17, 2025

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Remote and graceful represent the same concept. remote resumes are always ungraceful and vice versa.

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@oroztocil oroztocil Nov 17, 2025

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I see, I thought those were orthogonal properties. Then it simplifies the change. I will update the PR.

};

export type ReconnectOptions = {
Expand Down
1 change: 1 addition & 0 deletions src/Components/Web.JS/src/Platform/Circuits/ReconnectStateChangedEvent.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -3,4 +3,5 @@ export interface ReconnectStateChangedEvent {
currentAttempt?: number;
secondsToNextAttempt?: number;
remote?: boolean;
graceful?: boolean;
}
3 changes: 2 additions & 1 deletion src/Components/Web.JS/src/Platform/Circuits/UserSpecifiedDisplay.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -71,9 +71,10 @@ export class UserSpecifiedDisplay implements ReconnectDisplay {
}
if (options.type === 'pause') {
const remote = options.remote;
const graceful = options.graceful;
this.dialog.classList.remove(UserSpecifiedDisplay.ShowClassName, UserSpecifiedDisplay.RetryingClassName);
this.dialog.classList.add(UserSpecifiedDisplay.PausedClassName);
this.dispatchReconnectStateChangedEvent({ state: 'paused', remote: remote });
this.dispatchReconnectStateChangedEvent({ state: 'paused', remote: remote, graceful: graceful });
}
}

Expand Down
8 changes: 4 additions & 4 deletions ...mplates/content/BlazorWeb-CSharp/BlazorWebCSharp.1/Components/Layout/ReconnectModal.razor
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Expand Up @@ -25,11 +25,11 @@
<p class="components-pause-visible">
The session has been paused by the server.
</p>
<button id="components-resume-button" class="components-pause-visible">
Resume
</button>
<p class="components-resume-failed-visible">
Failed to resume the session.<br />Please reload the page.
Failed to resume the session.<br />Please retry or reload the page.
</p>
<button id="components-resume-button" class="components-pause-visible components-resume-failed-visible">
Resume
</button>
</div>
</dialog>
2 changes: 1 addition & 1 deletion ...ates/content/BlazorWeb-CSharp/BlazorWebCSharp.1/Components/Layout/ReconnectModal.razor.js
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Expand Up @@ -15,7 +15,7 @@ function handleReconnectStateChanged(event) {
reconnectModal.close();
} else if (event.detail.state === "failed") {
document.addEventListener("visibilitychange", retryWhenDocumentBecomesVisible);
} else if (event.detail.state === "rejected") {
} else if (event.detail.state === "rejected" || (event.detail.state === "resume-failed" && !!event.detail.graceful)) {
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@javiercn javiercn Nov 17, 2025

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Suggested change
} else if (event.detail.state === "rejected" || (event.detail.state === "resume-failed" && !!event.detail.graceful)) {
} else if (event.detail.state === "rejected" || (event.detail.state === "resume-failed" && event.detail.remote))

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@snympi snympi Nov 17, 2025

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@javiercn your earlier suggestion of just
} else if (event.detail.state === "rejected" || event.detail.state === "resume-failed") {
provides a better empty new circuit experience.

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@javiercn javiercn Nov 17, 2025

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Hmm, not sure what you mean. We don't want to reload the page unconditionally when the circuit fails to resume. We only want to do that when it happens as a result of the app disconnecting, but not when the app explicitly pauses the circuit.

For ungraceful disconnections the client is not in control, but for pausing and then resuming, the client is. We don't want to unconditionally reload the page by default because that precludes users from saving any data that they had on the page.

Example, you are filling in a long form field, you switch to a different tab. Your JS code "pauses" the circuit when the visibility changes. When the user comes back to the tab and you try to "resume" the circuit, if for some reason the resume operation fails, we don't want to result in a refresh.

In the case of reconnection, the client app is not in control, but in case of reconnection, the client triggered the "pause" operation in the first place and should have some code to handle things when the "resume" goes wrong.

I would argue that automatically reloading is also a bad policy to have for reconnection, as you run into a similar problem, but I think that ship has sailed.

We want to restore the behavior for failed reconnections + failed resumes by default, but we don't want to automatically reload the page in case of failed resumes when the app triggered the pause.

location.reload();
}
}
Expand Down
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