Catch exception error but without http error code

[leotu]

Document say that when http response error would return statusCode (404, 304, 500,...)
i.e,

fetch('GET', url, headers)
      .then((response) => {  // when response status code is 200
         ...
      })
      .catch((errorMessage, statusCode) => {   // Status code is not 200
                            ^^^^^^^^^^^^
          ...
      }

But I always get undefined for variable: "statusCode".

Additional Information:
react-native: 0.29.2
react-native-fetch-blob: 0.9.4
iOS: 8.X & 9.X

[wkh237]

@leotu , thank you for the information, I'll try to add the missing part and update the status in this thread : )

[wkh237]

@leotu , after some investigation I think this is a design error on IOS, a response with status code other than 2xx should not cause a promise rejection. Therefore I've changed the implementation and published a new version 0.9.5-beta.3. Please try install this version and you should be able to handle the request status code directly in then block instead of catch block.

RNFetchBlob.fetch('GET', 'http://www.example.com')
.then((res) => {
    let statusCode = Math.floor(res.info().status)
})

Thank you !

[leotu]

Ok, I will try it.
Catch http status code is very important that I need to control my cache design.
i.e, use Etag & If-None-Match communicate with "Images Web Server".
for example: return 404 for using default image, 304 for using local cache image.

There is another issue about "path". If path is my local cache file and it existing.
When raise exception (http code 304), my existing file size will become 0, would you provide control property tell it don't override my file content!

  var headers =  {
        'If-None-Match': xxxxx,   // Etag
      }

  RNFetchBlob.config({
      timeout: 1000 * 10, // milliseconds
      path: existPathFile,
    }).
    fetch('GET', url, headers)
      .then((response) => {  // when response status code is 200
        // refresh image
        callback(response.path()); //  for  <Image style={{uri: response.path(), ...}
      })
      .catch((errorMessage, statusCode) => {   // Status code is not 200
          // cache image, Not Modified
        if (statusCode == 304) {  // FIXME: existPathFile length become 0 ?
                        ^^^^^^
           callback(existPathFile); //  for  <Image style={{uri: existPathFile, ...}
        }
       else { // 404, 500,...    // default image
           callback(defaultImageSrc); //  for  <Image style={{uri: defaultImageSrc, ...}
        }
      ...

[wkh237]

@leotu , thanks for your information 👍 Specifying path in config, that will force the response body write to the location regardless the original one, when the response is 304 the response body is empty so the original file becomes an empty file.

Perhaps you can try use the following workaround with 0.9.5-beta.3

import RNFB from 'react-native-fetch-blob'
const {fetch, fs} = RNFB

RNFB.config({
    fileCache : true
})
.fetch('GET', url, headers)
.then((res) => {
    let status = Math.floor(res.info().status)
    switch(status) {
        // replace the existing file with the new one
        case 200 : 
        fs.mv(res.path(), existPathFile).then(() => {  callback(res.path()) })
        break
        // resource not modified
        case 304 :
        callback(res.path())
        break
        // hanlding HTTP request error
        default :
        callback(defaultImageSrc)
        break
    }
})
// handle network and socket errors
.catch((err) => { ... })

[leotu]

It works.
"0.9.5-beta.3"

Thanks.

[DazChong]

res.info().status is useful but not documented. Could you add it to the README.md as a comment? thanks!