I want to intercept fetch API requests and responses in JavaScript. For example, before sending the request I want to intercept the request URL. I’d like to intercept the response once it arrives as well. The below code is for intercepting responses of all XMLHTTPRequests. I want to implement the same feature for fetch() API. How can I do this?
Tag: fetch-api
Stream response to file using Fetch API and fs.createWriteStream
I’m creating an Electron application and I want to stream an image to a file (so basically download it). I want to use the native Fetch API because the request module would be a big overhead. But there is no pipe method on the response, so I can’t do something like So how can I combine fetch and fs.createWriteStream? Answer
ReactJS “Unhandled Rejection (TypeError): this.state.features.map is not a function”
I’m learning React and now I’m trying to do a get request and list with map but when I run this code they come up with this error “Unhandled Rejection (TypeError): this.state.features.map is not a function”. I have already searched this but I do not understand what is going on. Answer In your componentWillMount, just do this: The response you
fetch response.text() returns pending promise
I test the fetch API with jsonplaceholder URL, but my function returns “Promise State: Pending”, and I don’t understand why : I think the problem is because of asynchronous/synchronous methods? Answer I think the problem become asynchrone/synchrone method ? Yes. You’ve (mostly) correctly consumed the original fetch() promise, but text() also returns a promise. So: At #1 above, we respond
JS Fetching batch data with HTTP
My RESTful service allows batching requests. I’m trying to combine requests into one batch with help of Fetch API: However it returns an error – bad request. I suppose I may combine HTTP requests in wrong way. Is there simpler way of doing this? Where in Network Chrome Dev Tools can I see nested HTTP requests? Answer Your code does
Text response is empty when using fetch
The following code: is outputting: If I use curl: I get a token in text form back (length != 0). And if I output the response header via: I get: Why am I getting no text via fetch? Answer Remove mode: ‘no-cors’. When you use no-cors mode, you’re explicitly specifying that you want an “opaque response”. Your script can’t access
Getting Text From Fetch Response Object
I’m using fetch to make API calls and everything works but in this particular instance I’m running into an issue because the API simply returns a string — not an object. Typically, the API returns an object and I can parse the JSON object and get what I want but in this case, I’m having trouble finding the text I’m
Retrieve data from a ReadableStream object?
How may I get information from a ReadableStream object? I am using the Fetch API and I don’t see this to be clear from the documentation. The body is being returned as a ReadableStream and I would simply like to access a property within this stream. Under Response in the browser dev tools, I appear to have this information organised
How to handle errors in fetch() responses with Redux-Saga?
I try to handle Unauthorized error from server using redux-saga. This is my saga: I fetch data like this: But anyway result is {type: ‘LOG_IN_SUCCEEDED’, user: undefined} when I expect {type: ‘LOG_IN_FAILED’, error: ‘Unauthorized’}. Where is my mistake? How to handle errors right using Redux-Saga? Answer Don’t handle the then and error in your fetchUser method and your saga. Since
Accessing object in returned promise using fetch w/ react js
I have this function: Which returns this in the console: Promise {[[PromiseStatus]]: “pending”, [[PromiseValue]]: undefined} proto [[PromiseStatus]] : “resolved” I need to access the name/value pairs in the object but I can’t get to them. I’m assuming I need to take one extra step after I convert the response to json but can’t figure it out. If anyone could help