JSON.stringify 在 Angular Universal 中的 SSR 期间抛出错误但适用于 locahost “TypeError: Converting circle structure to JSON”

Question

I have the following in my angular component

JSON.stringify({ "webSlug": slug });

that works fine on localhost when serving the app with ng serve , but when universal tries to server-side render on a node app. The server console shows the following error... How can i rewrite this or resolve the error?

ERROR { TypeError: Converting circular structure to JSON
0|amec  |     at JSON.stringify (<anonymous>)
0|amec  |     at readableObjectToString (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:669:63)
0|amec  |     at resolvePromise (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:831:69)
0|amec  |     at resolvePromise (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:788:17)
0|amec  |     at /home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:892:17
0|amec  |     at ZoneDelegate.invokeTask (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:423:31)
0|amec  |     at Object.onInvokeTask (/home/ec2-user/packages/core/src/zone/ng_zone.ts:262:25)
0|amec  |     at ZoneDelegate.invokeTask (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:422:60)
0|amec  |     at Zone.runTask (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:195:47)
0|amec  |     at drainMicroTaskQueue (/home/ec2-user/amec_compiled/node_modules/zone.js/dist/zone-node.js:601:35)
0|amec  |   rejection: 
0|amec  |    HttpErrorResponse {
0|amec  |      headers: HttpHeaders { normalizedNames: Map {}, lazyUpdate: null, headers: Map {} },
0|amec  |      status: 0,
0|amec  |      statusText: 'Unknown Error',
0|amec  |      url: null,
0|amec  |      ok: false,
0|amec  |      name: 'HttpErrorResponse',
0|amec  |      message: 'Http failure response for (unknown url): 0 Unknown Error',
0|amec  |      error: 
0|amec  |       ProgressEvent {
0|amec  |         type: 'error',
0|amec  |         target: [XMLHttpRequest],
0|amec  |         currentTarget

Answer 1

I had that error once, and the cause was actually a HTTP request sent by angular universal was unsuccessful. So the part about converting a circular structure to json was misleading.

I think it's the same for you here, based on the following message

message: 'Http failure response for (unknown url): 0 Unknown Error',

Make sure that angular universal can send requests to your API or whatever url you are calling. It can just be that the SSL certificate of the target server is invalid (if I remember correctly, that was my problem)

Answer 2

I had the same issue. As @David said, The issue was due to the locally generated SSL certificate. When you run in the browser (ng serve), the local SSL certificate is already trusted and won't be an issue. But for the SSR certificate is not valid.