#Fetch download file full
#Fetch download file code

What if we need binary content instead of a string? That’s even simpler. The built-in TextDecoder does exactly that. To create a string, we need to interpret these bytes. set(chunk, position) method to copy each chunk one after another in it. We create chunksAll = new Uint8Array(receivedLength) – a same-typed array with the combined length.

#Fetch download file code

Unfortunately, there’s no single method that concatenates those, so there’s some code to do that: I will use link as well as button for downloading the same file from the server. In the view file I will give users two options for downloading the same file. We need to join them into a single result. I have created service class to fetch file data from a server URL but I need to provide a link or button for downloading the file. That’s important, because after the response is consumed, we won’t be able to “re-read” it using response.json() or another way (you can try, there’ll be an error).Īt the end, we have chunks – an array of Uint8Array byte chunks. We gather response chunks in the array chunks. But usually it’s at place.Ĭall await reader.read() until it’s done. It may be absent for cross-origin requests (see chapter Fetch: Cross-Origin Requests) and, well, technically a server doesn’t have to set it.

#Fetch download file full

Prior to reading, we can figure out the full response length from the Content-Length header. Please note, we can’t use both these methods to read the same response: either use a reader or a response method to get the result. We perform fetch as usual, but instead of calling response.json(), we obtain a stream reader (). Let result = new TextDecoder('utf-8').decode(chunksAll) Let chunksAll = new Uint8Array(receivedLength) // (4.1) For Firefox it is necessary to delay revoking the ObjectURL. For other browsers: create a link pointing to the ObjectURL containing the blob. Step 4: concatenate chunks into single Uint8Array // It is necessary to create a new blob object with mime-type explicitly set for all browsers except Chrome, but it works for Chrome too. Let chunks = // array of received binary chunks (comprises the body)Ĭonst `) Let receivedLength = 0 // received that many bytes at the moment Collaborating them in will give the account access to the data. To fetch the files you will auth as the service account and simply make a call to fetch that file or folder. Collaborate the service account in on all files / folders you want access to. Step 1: start the fetch and obtain a readerĬonst reader = () Ĭonst contentLength = +('Content-Length') Auth as the service account, then make an As-User call on behalf of that user to fetch the file.