Question

我正在使用redux thunk来获取动作中的一些数据

from farmhelper import *
from random import *

# Field for holding the crops.
class Field():
    def rain(self):
        for i in range(len(self.plants)):
            self.plants[i].water()

    def __init__(self, size, crop):
        self.plants = [0] * size
        for i in range(size):
            self.plants[i] = crop()

class Combine():
    def harvest(self, field):
        quantity = 0
        for i in range(len(field.plants)):
            quantity += field.plants[i].harvest()
        return quantity

# Create fields with 10,000 of each crop

cornField = Field(10000, Corn)
wheatField = Field(10000, Wheat)

# Create irrigators for each field

cornIrrigator = Irrigator(20000)
wheatIrrigator = Irrigator(500)

# Create a combine for harvesting
combine = Combine()


# 90 days ~3 months of growth
for i in range(90):
    # Low chance of rain
    if randint(0, 100) > 95:
        print("It rained")
        cornField.rain()
        wheatField.rain()
    # Always run the irrigators. Since they are never
    # refilled they will quickly run out
    cornIrrigator.irrigate(cornField)
    wheatIrrigator.irrigate(wheatField)

# Gather the crops - DONE
earsOfCorn = combine.harvest(cornField)
headsOfWheat = combine.harvest(wheatField)

# Print the result - DONE
print("Grew", earsOfCorn, "ears of corn")
print("and", headsOfWheat, "heads of wheat")

我的快速服务器出现错误时会回复'some error'

function handleErrors(response) {
    console.log(response)
    if (!response.ok) {
        throw Error(response.statusText);
    }
    return response;
}

export const something = (var) => dispatch => {
    fetch(`${url}/something`, {credentials: 'include'})
    .then(handleErrors)
    .then(res => res.json())
    .then(res =>
        dispatch({
            type: SOMETHING,
            payload: res
        })
    )
    .catch(error => 
        dispatch({
            type: ERROR,
            payload: error
        })
    )

当它获取并且是错误（500）时，其消息是通用的“内部服务器错误”。

如何获取fetch中的“some error”？

Answer 1

不确定handleError中有什么内容。提取错误消息的一种方法是这样的

fetch(url)
  .then(res => {
    // Check if response has errors
    if (res.ok) {
      // No errors
      return res.json();
    } else {
       // Has errors, since res.json() returns a Promise, we
       // chain a then here to get the value and return the err value
       // as Promise rejection so that it will go to the 
       // catch handler
       return res.json().then(err => Promise.reject(err));
       // this could also be
       // return res.json().then(err => throw Error(err));
    }
  })
  .then(json => {
    // dispatch success
  })
  .catch(err => {
    // dispatch error
  });

fetch api从服务器获取错误消息而不是通用消息

1 个答案: