vue-resource中$http请求的成功判定规则是什么？

Awesome question—let’s break this down clearly, since it’s all tied to HTTP standards and vue-resource’s built-in logic.

First, the core rule:

• HTTP status codes are the main driver
  vue-resource’s promise will fire the success callback when the server sends back an HTTP status code in the 2xx range (200 OK, 201 Created, 204 No Content, etc.). Any status code outside this range—like 400 Bad Request, 404 Not Found, or 500 Internal Server Error—will trigger the error callback instead.

And yes, the response object has a direct property that confirms this:

• Check response.ok for a boolean indicator
  The response object includes an ok property that’s true if the status code was in the 2xx range (success callback ran), and false otherwise (error callback ran). This is a quick way to verify the request’s outcome inside either callback.

Let’s map this to your exact code snippet:

this.$http.post('/someUrl', formData).then(
  // Success callback: triggers ONLY for 2xx status codes
  response => {
    console.log('Request worked!', response.ok); // Logs "true"
    console.log('Status code:', response.status); // e.g., 200
  },
  // Error callback: triggers for non-2xx status codes OR network failures
  response => {
    console.log('Request failed!', response.ok); // Logs "false"
    console.log('Issue status code:', response.status); // e.g., 404 or 500
  }
);

One edge case to note: If the request fails entirely at the network level (like no internet, or the server is totally unreachable), the error callback will still run. In these cases, the response object might have a statusText property explaining the network issue (e.g., "Network Error").

内容的提问来源于stack exchange，提问作者deterjan