fetch API or XMLHTTPRequest: How to get exact error reason for a network error?

How to retrieve exact information about a network error? Chrome browser prints things like "net::ERR_CONNECTION_TIMED_OUT" or "net::ERR_CERT_INVALID" into console but how can I retrieve them via JS? Is that possible to get them at all? Currently I use fetch API but I can switch to XMLHTTPRequest easily.

I need that to handle such errors to inform a user and let him know what does he need to do.

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

The fetch API use promises so you can easily get the errors with .catch(). It is what you are looking for ?

– Arkellys
Nov 13 '18 at 13:13

Nope. The error doesn't contain any specific information. It just says "TypeError: Failed to fetch"

– Andrey Gubanov
Nov 13 '18 at 13:16

You want to check the response status. The invalid cert for example should be a 400 series. Take a look at wretch wrapper for fetch(). Will simplify this for you

– charlietfl
Nov 13 '18 at 13:20

I don't want to check response status. I want to check "reason of failed request", where failed request doesn't have any code.

– Andrey Gubanov
Nov 13 '18 at 13:31

@charlietfl — It won't be a 400 because it will error at the TLS level not the HTTP level.

– Quentin
Nov 13 '18 at 13:35

add a comment |

I need that to handle such errors to inform a user and let him know what does he need to do.

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

The fetch API use promises so you can easily get the errors with .catch(). It is what you are looking for ?

– Arkellys
Nov 13 '18 at 13:13

Nope. The error doesn't contain any specific information. It just says "TypeError: Failed to fetch"

– Andrey Gubanov
Nov 13 '18 at 13:16

You want to check the response status. The invalid cert for example should be a 400 series. Take a look at wretch wrapper for fetch(). Will simplify this for you

– charlietfl
Nov 13 '18 at 13:20

I don't want to check response status. I want to check "reason of failed request", where failed request doesn't have any code.

– Andrey Gubanov
Nov 13 '18 at 13:31

@charlietfl — It won't be a 400 because it will error at the TLS level not the HTTP level.

– Quentin
Nov 13 '18 at 13:35

add a comment |

I need that to handle such errors to inform a user and let him know what does he need to do.

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

I need that to handle such errors to inform a user and let him know what does he need to do.

javascript xmlhttprequest fetch

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

asked Nov 13 '18 at 13:10

Andrey Gubanov

112

The fetch API use promises so you can easily get the errors with .catch(). It is what you are looking for ?

– Arkellys
Nov 13 '18 at 13:13

Nope. The error doesn't contain any specific information. It just says "TypeError: Failed to fetch"

– Andrey Gubanov
Nov 13 '18 at 13:16

You want to check the response status. The invalid cert for example should be a 400 series. Take a look at wretch wrapper for fetch(). Will simplify this for you

– charlietfl
Nov 13 '18 at 13:20

I don't want to check response status. I want to check "reason of failed request", where failed request doesn't have any code.

– Andrey Gubanov
Nov 13 '18 at 13:31

@charlietfl — It won't be a 400 because it will error at the TLS level not the HTTP level.

– Quentin
Nov 13 '18 at 13:35

add a comment |

The fetch API use promises so you can easily get the errors with .catch(). It is what you are looking for ?

– Arkellys
Nov 13 '18 at 13:13

Nope. The error doesn't contain any specific information. It just says "TypeError: Failed to fetch"

– Andrey Gubanov
Nov 13 '18 at 13:16

You want to check the response status. The invalid cert for example should be a 400 series. Take a look at wretch wrapper for fetch(). Will simplify this for you

– charlietfl
Nov 13 '18 at 13:20

I don't want to check response status. I want to check "reason of failed request", where failed request doesn't have any code.

– Andrey Gubanov
Nov 13 '18 at 13:31

@charlietfl — It won't be a 400 because it will error at the TLS level not the HTTP level.

– Quentin
Nov 13 '18 at 13:35

The fetch API use promises so you can easily get the errors with .catch(). It is what you are looking for ?

– Arkellys
Nov 13 '18 at 13:13

Nope. The error doesn't contain any specific information. It just says "TypeError: Failed to fetch"

– Andrey Gubanov
Nov 13 '18 at 13:16

You want to check the response status. The invalid cert for example should be a 400 series. Take a look at wretch wrapper for fetch(). Will simplify this for you

– charlietfl
Nov 13 '18 at 13:20

I don't want to check response status. I want to check "reason of failed request", where failed request doesn't have any code.

– Andrey Gubanov
Nov 13 '18 at 13:31

@charlietfl — It won't be a 400 because it will error at the TLS level not the HTTP level.

– Quentin
Nov 13 '18 at 13:35

add a comment |

1 Answer
1

active

oldest

votes

you can get the exact error as follow:

     fetch('url',

        {

            headers: {

                'Accept': 'application/json',

                'Content-Type': 'application/json'

            },

            method: "POST",

            body: JSON.stringify({data})

        })

        .then(function(response) {

            console.log(response);

            //handle here or in catch

         })

        .then(function(json){

            console.log("succeed json re");

        });

You'll get resolved response once your promise has been resolved.

Response.status will give you status code.
Response.statusText will give you exact error description as ERR_CONNECTION_TIMED_OUT. which will be in case of errors and then response.ok will be false.

For more info: FETCH

answered Nov 13 '18 at 14:45

Krina Soni

34515

"Response.statusText — A string (default value "OK"), which corresponds to the HTTP status code message." 1. ERR_CONNECTION_TIMED_OUT doesn't have any status code as I know. 2. When ERR_CONNECTION_TIMED_OUT happens, fetch API throws an error which means there is no way to get Response instance and read statusText property.

– Andrey Gubanov
Nov 13 '18 at 15:25

add a comment |

Your Answer

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53281740%2ffetch-api-or-xmlhttprequest-how-to-get-exact-error-reason-for-a-network-error%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

you can get the exact error as follow:

     fetch('url',

        {

            headers: {

                'Accept': 'application/json',

                'Content-Type': 'application/json'

            },

            method: "POST",

            body: JSON.stringify({data})

        })

        .then(function(response) {

            console.log(response);

            //handle here or in catch

         })

        .then(function(json){

            console.log("succeed json re");

        });

You'll get resolved response once your promise has been resolved.

For more info: FETCH

answered Nov 13 '18 at 14:45

Krina Soni

34515

"Response.statusText — A string (default value "OK"), which corresponds to the HTTP status code message." 1. ERR_CONNECTION_TIMED_OUT doesn't have any status code as I know. 2. When ERR_CONNECTION_TIMED_OUT happens, fetch API throws an error which means there is no way to get Response instance and read statusText property.

– Andrey Gubanov
Nov 13 '18 at 15:25

add a comment |

you can get the exact error as follow:

     fetch('url',

        {

            headers: {

                'Accept': 'application/json',

                'Content-Type': 'application/json'

            },

            method: "POST",

            body: JSON.stringify({data})

        })

        .then(function(response) {

            console.log(response);

            //handle here or in catch

         })

        .then(function(json){

            console.log("succeed json re");

        });

You'll get resolved response once your promise has been resolved.

For more info: FETCH

answered Nov 13 '18 at 14:45

Krina Soni

34515

"Response.statusText — A string (default value "OK"), which corresponds to the HTTP status code message." 1. ERR_CONNECTION_TIMED_OUT doesn't have any status code as I know. 2. When ERR_CONNECTION_TIMED_OUT happens, fetch API throws an error which means there is no way to get Response instance and read statusText property.

– Andrey Gubanov
Nov 13 '18 at 15:25

add a comment |

you can get the exact error as follow:

     fetch('url',

        {

            headers: {

                'Accept': 'application/json',

                'Content-Type': 'application/json'

            },

            method: "POST",

            body: JSON.stringify({data})

        })

        .then(function(response) {

            console.log(response);

            //handle here or in catch

         })

        .then(function(json){

            console.log("succeed json re");

        });

You'll get resolved response once your promise has been resolved.

For more info: FETCH

answered Nov 13 '18 at 14:45

Krina Soni

34515

you can get the exact error as follow:

     fetch('url',

        {

            headers: {

                'Accept': 'application/json',

                'Content-Type': 'application/json'

            },

            method: "POST",

            body: JSON.stringify({data})

        })

        .then(function(response) {

            console.log(response);

            //handle here or in catch

         })

        .then(function(json){

            console.log("succeed json re");

        });

You'll get resolved response once your promise has been resolved.

For more info: FETCH

answered Nov 13 '18 at 14:45

Krina Soni

34515

answered Nov 13 '18 at 14:45

Krina Soni

34515

answered Nov 13 '18 at 14:45

Krina Soni

34515

answered Nov 13 '18 at 14:45

Krina Soni

34515

"Response.statusText — A string (default value "OK"), which corresponds to the HTTP status code message." 1. ERR_CONNECTION_TIMED_OUT doesn't have any status code as I know. 2. When ERR_CONNECTION_TIMED_OUT happens, fetch API throws an error which means there is no way to get Response instance and read statusText property.

– Andrey Gubanov
Nov 13 '18 at 15:25

add a comment |

"Response.statusText — A string (default value "OK"), which corresponds to the HTTP status code message." 1. ERR_CONNECTION_TIMED_OUT doesn't have any status code as I know. 2. When ERR_CONNECTION_TIMED_OUT happens, fetch API throws an error which means there is no way to get Response instance and read statusText property.

– Andrey Gubanov
Nov 13 '18 at 15:25

"Response.statusText — A string (default value "OK"), which corresponds to the HTTP status code message." 1. ERR_CONNECTION_TIMED_OUT doesn't have any status code as I know. 2. When ERR_CONNECTION_TIMED_OUT happens, fetch API throws an error which means there is no way to get Response instance and read statusText property.

– Andrey Gubanov
Nov 13 '18 at 15:25

add a comment |

draft saved

draft discarded

Thanks for contributing an answer to Stack Overflow!

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

搜尋此網誌

Nrthugu