I have ASP.NET Core MVC back-end api. One controller returns File from server. Is there a way to make request to api route by [href] attribute of <a> tag? Looks like it tries to call React route but not make a request to server.
Also I made AJAX call to that controller and got back file as a string (screenshot is attached). Why is it a string, shouldn.t it be a byte array? How to build back file from that string? (it's a .pdf file). I have an empty PDF if use JavaScript new File([], 'name', {options}).
ASP.NET Core controller returns PDF this way:
return PhysicalFile(Path.GetFullPath(relativePath), "application/pdf", reportName);
In React I receive it as a string this way:
let stringPDFBinary = await ReportService.getReport(id, reportFileName)
I just need to download file from api by any way.
So, the answer is here: PDF is blank when downloading using javascript
The same problem. Let it be one more topic, easier to find for others. The AJAX response is encoded string. In request config set 'responseType = 'arraybuffer'' somehow and receiving pdf will not be blank. Solved.
I Just copied and pasted from the code source. The problem seems to be the same that i had:
Asp net controller:
[HttpGet]
[Route("File")]
[AllowAnonymous]
public IActionResult GetFile(string key)
{
var file = (FileCacheValue)_fileCache.Cache[key.Replace(" ", "+")];
if (file == null)
return NotFound();
Response.Headers["content-disposition"] = $"inline;filename={file.Name}.pdf";
return File(file.Data, "application/pdf");
}
In this case comes from a cache system. The data is a byte array.
Front-end React:
const onClick = () =>
{
window.open(pdfByteArray, '_blank', 'fullscreen=yes');
}
Exactly what i have. I just put the data on a new window and open the pdf.
The Ajax part is straight forward, get the value from the response and set it on a variable
Related
I have an autocomplete section that searches movies through MovieDB api.
The result of the api has a field called poster_path that contains the path where the image exists.
"poster_path": "/lRQiJXETkCnVVurHmglNvMXrZOx.jpg"
I have a react project for front-end and a spring boot project for backend.
The thing I want to do is to get the image convert it to file and the send it to the backend controller as a multipart file.
How can I convert the image from url to file in React?
I've tried this but re.data returns the byte array I think:
axios.get(e.image).then(re => {
setFile(re.data)
});
And here is the controller:
public ResponseEntity<Post> post(#RequestPart(required = false) MultipartFile file, #RequestPart #Valid PostResource postResource, Principal principal)
I am trying to select a local json file and load it in my blazor client component.
<input type="file" onchange="LoadFile" accept="application/json;.json" class="btn btn-primary" />
protected async Task LoadFile(UIChangeEventArgs args)
{
string data = args.Value as string;
}
P,S I do not understand , do i need to keep track both the name of the file and the content when retrieving it ?
I guess you're trying to read the contents of a JSON file on the client (Blazor), right? Why not on the server !?
Anyhow, args.Value can only furnish you with the name of the file. In order to read the contents of the file, you can use the FileReader API (See here: https://developer.mozilla.org/en-US/docs/Web/API/FileReader). That means that you should use JSIntrop to communicate with the FileReader API. But before you start, I'd suggest you try to find out if this API have been implemented by the community (something like the localStorage, etc.). You may also need to deserialize the read contents into something meaningful such as a C# object.
Hope this helps...
There is a tool that can help, but it currently doesn't support the 3.0 preview. https://github.com/jburman/W8lessLabs.Blazor.LocalFiles
(no affiliation with the developer)
The input control will give you the location of the file as a full path along with the name of the file. Then you still have to retrieve the file and download it to the server.
Late response but with 3.1 there is an additional AspNetCore.Components module you can download via NuGet to get access to HttpClient extensions. These make it simple:
// fetch mock data for now
var results = await _http.GetJsonAsync<WellDetail[]>("sample-data/well.json");
You could inject the location of the file from your input control in place of the "sample-data/well.json" string.
Something like:
using Microsoft.AspNetCore.Components;
private async Task<List<MyData>> LoadFile(string filePath)
{
HttpClient _http;
// fetch data
// convert file data to MyData object
var results = await _http.GetJsonAsync<MyData[]>(filePath);
return results.ToList();
}
I am opening a webpage in the cefsharp browser and trying to send a set of JSON data to my website's .aspx page along with query string. While the query string is not an issue but sending the JSON data to the same URL is what I am trying to fix. Earlier I was using Window's native WebBrowser control's Navigate method where I was passing the URL along with query string as well as a byte array. But, I don't find any such method to post the data. Various discussion and posts regarding the same don't have a clear example. Can you provide a sample code/example to show how to achieve that? Here is the code I've been using:
ChromiumWebBrowser browser = new ChromiumWebBrowser();
browser.Address = "https://webhook.site";
browser.Width = System.Windows.SystemParameters.PrimaryScreenWidth;
browser.Height = System.Windows.SystemParameters.PrimaryScreenHeight;
browser.RequestHandler = this;
browser.IsBrowserInitializedChanged += (sender, args) =>
{
if (browser.IsBrowserInitialized)
{
browser.LoadUrlWithPostData("https://webhook.site/#/cba9d04b-01ff-40ef-b223-0917d127ecbe/6ce82e34-28df-4900-88ef-c932a446c6b0/1", Encoding.UTF8.GetBytes("test=123&data=456"));
}
};
I want to download file that can be in any format viz. pdf, jpeg, png, xlsx, csv etc. The download API on backend using pyramid framework is sending FileResponse as below:
def delivery_item_download_view(request, *args, **kw):
context = request.context
item_row = context.item_row
if item_row and item_row["deleted_at"] is None:
print(request.upload_dir+'/'+item_row["file_name"]+'.'+item_row["file_extension"])
response = FileResponse(
request.upload_dir+'/'+item_row["file_name"]+'.'+item_row["file_extension"],
request=request,
)
response.headers["attachment"] = item_row["name"];
return response
This, when executed using POSTMAN works as expected giving file as output. However,when tried implementing same using ReactJS, it's not working as expected. My client-code is as below:
onDownloadItem= (item) => {
console.log("item id is:", item.item_id)
var apiBaseUrl = "https://dev.incodax.com/api/deliveries_items/"+ item.item_id+ "/download";
fetch(apiBaseUrl, {
method: "GET",
}).then((res) => {
fileDownload(res,item.file_name)
console.log(res)
})
}
This fileDownload function simply downloading file but with no content inside. In downloaded file I could see something like:
[object Response]
I am getting 200 response from server. So I dont't think there is any issue with server side code. How can I handle it on client?
Thanks in advance
Will it suit you if you just redirected user to link to file? Browser will automatically handle it and download it.
The issue is in your fileDownload function which you do not post here. It's not clear what the first parameter is supposed to be but likely it is not the response object. Likely you at least need to pull the body out of the response and save that! The response body can be converted to a buffer object which could work (again it depends on what fileDownload is expecting):
res.arrayBuffer().then(buffer => {
fileDownload(buffer, item.file_name);
});
I am using Angular js to show loading screen. It works for all the REST services call except REST service to download the file. I understand why it is not working because for download I am not making any service call using $resource; instead of that I am using normal approach to download the file therefore Angular js code doesn't have any control on start/finish the service request. I tried to use $resource to hit this REST service however I am getting the data from this service and in this case loading screen was working fine however not sure how to use this data to display to user to download in angular way. Following are required details. Please help.
Approach 1 using iframe approach:
/*Download file */
scope.downloadFile = function (fileId) {
//Show loading screen. (Somehow it is not working)
scope.loadingProjectFiles=true;
var fileDownloadURL = "/api/files/" + fileId + "/download";
downloadURL(fileDownloadURL);
//Hide loading screen
scope.loadingProjectFiles=false;
};
var $idown; // Keep it outside of the function, so it's initialized once.
var downloadURL = function (url) {
if ($idown) {
$idown.attr('src', url);
} else {
$idown = $('<iframe>', { id: 'idown', src: url }).hide().appendTo('body');
}
};
Approach 2 using $resource (Not sure how to display data on screen to download)
/*Download file */
scope.downloadFile = function (fileId) {
//Show loading screen (Here loading screen works).
scope.loadingProjectFiles=true;
//File download object
var fileDownloadObj = new DownloadFile();
//Make server call to create new File
fileDownloadObj.$get({ fileid: fileid }, function (response) {
//Q? How to use the response data to display on UI as download popup
//Hide loading screen
scope.loadingProjectFiles=false;
});
};
This is the correct pattern with the $resource service:
scope.downloadFile = function (fileId) {
//Show loading screen (Here loading screen works).
scope.loadingProjectFiles=true;
var FileResource = $resource('/api/files/:idParam', {idParam:'#id'});
//Make server call to retrieve a file
var yourFile = FileResource.$get({ id: fileId }, function () {
//Now (inside this callback) the response data is loaded inside the yourFile variable
//I know it's an ugly pattern but that's what $resource is about...
DoSomethingWithYourFile(yourFile);
//Hide loading screen
scope.loadingProjectFiles=false;
});
};
I agree with you that this is a weird pattern and is different of other APIs where the downloaded data is assigned to a parameter in a callback function, hence your confusion.
Pay attention to the names and the cases of the parameters, and look that there're two mappings involved here, one between the caller to the $resource object and the object itself, and another between this object and the url that it contructs for downloading the actual data.
Here are some idea's for the second approach, you could present the user with a link after the download has happened:
With a "data url". Probably not a good idea for large files.
With a URL like "filesystem:mydownload.zip" You'd first have to save the file with the filesystem API. You can find some inspiration on html5rocks