I have a Blazor Webassembly project with a controller method as follows:
[HttpGet]
public async Task<List<string>> GetStatesForProfile()
{
IConfigurationSection statesSection = configuration.GetSection("SiteSettings:States");
var sections = statesSection.GetChildren();
var states = statesSection.GetChildren().Select(s => s.Key).ToList<string>();
return states;
}
The razor page calls this method:
private async Task<bool> GetStatesModel()
{
try
{
States = await http.GetJsonAsync<List<string>>("api/account/getstatesforprofile");
...
}
catch (Exception ex)
{
Console.WriteLine($"Exception: {ex.Message}, Inner: {ex.InnerException.Message}");
}
I get this Exception:
Exception: '<' is an invalid start of a value.
I read these values from appsettings.json file, And there is no '<' in values.
{
"SiteSettings": {
"States": {
"New York": ["NYC"],
"California": ["Los Angeles", "San Francisco"]
}
}
Also I put a breakpoint in the controller method and it doesn't hit.
What is this error? Is it from parsing json? and how to resolve this?
I had a very similar problem.
In the end it turned out that my browser had cached the HTML error page (I guess I had some problems with the code when I first tried it). And no matter how I tried fixing the code I still only got the error from cache. Clearing my cache also cleared the problem.
It happens when you're trying to access an API that doesn't exist. You have to check your API project connectionstring under AppSettings and make sure it's correct and running. If it's a Blazor project, you can set it as your default project, execute and see if you get a json response.
Most probably the response you are receiving is html instead of actual JSON format for the endpoint you are requesting. Please check that.
An as HTML usually starts with <html> tag, the JSON validator fails on the very first character.
You should also clear any cache, that might be interfering with the returned data. (this has helped people resolve this same issue)
I know this is an old question, but it's one of the top results when Googling the error.
I've just spent more time than I care to admit to tracking down this error. I had a straightforward Blazor hosted app, basically unchanged from the template. It worked just fine when run locally, but when published to my web host API calls failed. I finally figured out that the problem was that I was running the publish from the Client project. When I changed to the Server project it worked properly.
Hopefully my long frustration and slight stupidity will save someone else making a similar mistake.
Seems like your api is not not accessible and its returning error HTML page by default.
You can try below solution:-
I think you are using httpclient to get data to blazor application.
If you have separate projects in solution for blazor and web api,
currently your startup application may set to run blazor project only.
Change startup projects to multiple (blazor and web api app) and give httpClient url in startup of blazor application, as webApi application url, that may solve your issue.
This error indicates a mismatch of the project targeting framework version and installed runtime on the machine. So make sure that the target framework for your project matches an installed runtime - this could be verified by multiple means; one of them is to check out the Individual Components tab of the Visual Studio Installer and lookup the target version.
E.g., there is the TargetFramework attribute in the proj file:
<PropertyGroup>
<TargetFramework>net5.0</TargetFramework>
</PropertyGroup>
Then launch the Visual Studio Installer, click Modify, and visit the Individual Components tab:
Install the missing runtime (.NET 5 Runtime in this case) and you're good to go.
I got the same error. Red herring. use your browser or postman to check your api endpoint is returning the json data and not some HTML. In my case my "api/companytypes" had a typo.
private CompanyType[] companytypesarray;
private List<CompanyType> CompanyTypeList;
private List<CompanyType> CompanyTypeList2;
public async Task<bool> LoadCompanyTypes()
{
//this works
CompanyTypeList = await Http.GetFromJsonAsync<List<CompanyType>>("api/companytype");
//this also works reading the json into an array first
companytypesarray = await Http.GetFromJsonAsync<CompanyType[]>("api/companytype");
CompanyTypeList2 = companytypesarray.ToList();
return true;
}
I know this is an old question, but I had the same problem. It took some searching, but I realized that the return data was in XML instead of JSON.
I'm assuming your "http" variable is of type HttpClient, so here's what I found worked for me.
By setting the "Accept" header to allow only JSON, you avoid a miscommunication between your app and the remote server.
http.DefaultRequestHeaders.Add("Accept", "application/json");
States = await http.GetJsonAsync<List<string>>("api/account/getstatesforprofile");
I had the same issue when passing in an empty string to a controller method. Creating a second controller method that doesn't accept any input variables, and just passing an empty string to the first method helped to fix my problem.
[HttpGet]
[ActionName("GetStuff")]
public async Task<IEnumerable<MyModel>> GetStuff()
{
return await GetStuff("");
}
[HttpGet("{search}")]
[ActionName("GetStuff")]
public async Task<IEnumerable<MyModel>> GetStuff(string search)
{
...
}
Versions of package
Try to update your packages to old or new version. In my case, system.net.http.json is updated from 6.0 to 5.0
Likely you are using an Asp.NetCore hosted WASM application. By default the client's App.razor has something similar to:
<CascadingAuthenticationState>
<Router AppAssembly="#typeof(Program).Assembly">
<Found Context="routeData">
<AuthorizeRouteView DefaultLayout="#typeof(MainLayout)"
RouteData="#routeData">
<NotAuthorized>
<RedirectToLogin />
</NotAuthorized>
<Authorizing>
<Loading Caption="Authorizing..."></Loading>
</Authorizing>
</AuthorizeRouteView>
</Found>
<NotFound>
<LayoutView Layout="#typeof(MainLayout)">
<p>Sorry, there's nothing at this address.</p>
</LayoutView>
</NotFound>
</Router>
</CascadingAuthenticationState>
Herein lies the problem. Since the Client and Server share the same base address, when the application cannot find "api/account/getstatesforprofile" it gives you the client's "Sorry, there's nothing at the address" page. Which is of course HTML.
I have not found the solution to this issue, but I am working on it and will reply once I find an issue.
I was having the same problem,
"JsonReaderException: '<' is an invalid start of a value."
In my case the url for the REST service was wrong.
I was using the URL from the client project. Then I looked at the Swagger screen,
https://localhost:44322/swagger/index.html
and noticed the right URL should start with "44322"...
Corrected, worked.
In my case, I had a comma (,) written mistakenly at the beginning of the appsettings.json file ...
Just check your file and verify
///////
my error details
//////
System.FormatException HResult=0x80131537 Message=Could not parse the JSON file.
Source=Microsoft.Extensions.Configuration.Json StackTrace: at line 16 This exception was originally thrown at this call stack: [External Code] Inner Exception 1: JsonReaderException: ',' is an invalid start of a value. LineNumber: 0 | BytePositionInLine: 0.
////
For me, most of the time it is the #lauri-peltonen answer above. However, now and again, depending on who wrote the controller I have found that this will work in Swagger but not when you call it via the client (at least in this Blazor project we are on.)
[HttpGet]
[Route("prog-map-formulations")]
public async Task<List<GetProgramMapFormulationsResult>> GetProgramMapFormulations(int formulationId)
{
...
}
It sends the request as:
api/formulation-performance-program-map/analytical-assoc-values?formulationId=1
And I get results in Swagger but failes with the '<' OP error.
When I change ONLY the route to:
[HttpGet]
[Route("prog-map-formulations/{formulationId:int}")]
public async Task<List<GetProgramMapFormulationsResult>> GetProgramMapFormulations(int formulationId)
{
...
}
It sends the request as:
api/formulation-performance-program-map/analytical-assoc-values/1
And this works in both Swagger as well as from the Client side in Blazor.
Of course, once updated, I did have to clear the cache!
If you delete "obj" folder in your directory then clean the solution and rebbuild it the exception will be resolved
In all these, there is two things that was my issue and realized, first off was that Route[("api/controller")] instead of Route[("api/[controller]")], that is missing square brackets. In the second exercise I was doing, with the first experience in mind, was from the name of the database. The database had a dot in the name (Stock.Inventory). When I change the database name to StockInventory it worked. The second one I am not so sure but it worked for me.
I want to pass a parameter to my google spreadsheet with a get request. The get parameter name is 'pid', which seems to make Google Sheets crash.
My example script just returns the get parameters to the client:
function doGet(e){
try {
return ContentService
.createTextOutput(JSON.stringify({"result":"your parameters", "parameters": e.parameter}))
.setMimeType(ContentService.MimeType.JSON);
} catch(ee){
return ContentService
.createTextOutput(JSON.stringify({"result":"error", "error message": ee}))
.setMimeType(ContentService.MimeType.JSON);
}
}
The following request works:
https://script.google.com/macros/s/<sheet-id-here>/exec?a=1
returns:
{"result":"your parameters","parameters":{"a":"1"}}
But simply changing the get parameter name returns an error:
https://script.google.com/macros/s/<sheet-id-here>/exec?pid=1
returns:
We're sorry, a server error occurred. Please wait a bit and try again.
Any idea what's going on here and how to fix this? Is this a bug? Is there a way to handle this on the server side (can't really change my client code)?
It seems Google has changed reserved parameters. As written in the documentation,
Warning: The following parameter names are reserved by the system and shouldn't be used in URL parameters or POST bodies:
c
sid
Using these parameters may result in an HTTP 405 response with the error message "Sorry, the file you have requested does not exist." If possible, update your script to use different parameter names.
It seems both c and sid parameters are valid now and pid parameter is reserved and throws
Sorry, unable to open the file at this time.
There doesn't seem to be anything that you can do server side.
I am facing an issue with quickstart php script here: https://developers.google.com/drive/v2/web/quickstart/php
When I run the script first time, it executes perfectly and the access token is stored in a file called: drive-php-quickstart.json
When I run the script second time, it gives me the error:
Error start:
Notice: Undefined index: expires_in in \google-api-php-client\src\Google\Client.php on line 485
Fatal error: Uncaught exception 'LogicException' with message 'refresh token must be passed in or set as part of setAccessToken' in
Error end:
My assumption is that access token been saved in the file is not in the right format.
Current format:
ya29.CODE-oN_Bearer36001/_ANOTHER-CODE-ANOTHER_ANOTHER_CODE
As you can see, it does not contain the variable "expires_in"
Any suggestions where I am going wrong ? I am running the script as it is, with no modifications.
I've debugged it.... The person who wrote it made a mistake by not calling json_encode before writing the auth result to the token.json file.
You can fix it by adding json_encode on line 45.
So...
file_put_contents($credentialsPath, $accessToken);
...should be:
file_put_contents($credentialsPath, json_encode($accessToken));
I've submitted feedback so hopefully it'll be fixed.
edit: same issue happens for the token refresh call in that same method
edit2: Here's my related comment in a Github discussion and an answer from Google: https://github.com/google/google-api-php-client/issues/263#issuecomment-186557360
I suggested something along the following lines:
if ($client->isAccessTokenExpired()) {
$refreshToken = $client->getRefreshToken();
$client->refreshToken($refreshToken);
$newAccessToken = $client->getAccessToken();
$newAccessToken['refresh_token'] = $refreshToken;
file_put_contents($credentialsPath, json_encode($newAccessToken));
}
Instead of:
// Refresh the token if it's expired.
if ($client->isAccessTokenExpired()) {
$client->refreshToken($client->getRefreshToken());
file_put_contents($credentialsPath, $client->getAccessToken());
}
Google has updated their PHP Quickstart, with an improved method to handle this:
// Exchange authorization code for an access token.
$accessToken = $client->fetchAccessTokenWithAuthCode($authCode);
$client->setAccessToken($accessToken);
// Refresh the token if it's expired.
if ($client->isAccessTokenExpired()) {
$client->fetchAccessTokenWithRefreshToken($client->getRefreshToken());
file_put_contents($credentialsPath, json_encode($client->getAccessToken()));
}
I am trying to understand the concept of JSON RPC and it's Perl implementation. Though I can fin d a lot of examples for Python/Java, I find surprisingly little or no examples for it in Perl.
I am following this example but am not sure it is complete. The example I had in mind was to add 2 integers. Now I have a very basic HTML page set up, like so:
<html>
<body>
<input type="text" name="num1"><br>
<input type="text" name="num2"><br>
<button>Add</button>
</body>
</html>
Next, based on the example above, I have 3 files:
test1.pl
# Daemon version
use JSON::RPC::Server::Daemon;
# see documentation at:
# https://metacpan.org/pod/distribution/JSON-RPC/lib/JSON/RPC/Legacy.pm
my $server = JSON::RPC::Server::Daemon->new(LocalPort => 8080);
$server -> dispatch({'/test' => 'myApp'});
$server -> handle();
test2.pl
#!/usr/bin/perl
use JSON::RPC::Client;
my $client = new JSON::RPC::Client;
my $uri = 'http://localhost:8080/test';
my $obj = {
method => 'sum', # or 'MyApp.sum'
params => [10, 20],
};
my $res = $client->call( $uri, $obj );
if($res){
if ($res->is_error) {
print "Error : ", $res->error_message;
} else {
print $res->result;
}
} else {
print $client->status_line;
}
myApp.pl
package myApp;
#optionally, you can also
use base qw(JSON::RPC::Procedure); # for :Public and :Private attributes
sub sum : Public(a:num, b:num) {
my ($s, $obj) = #_;
return $obj->{a} + $obj->{b};
}
1;
While I understand what these files individually do, I am at a complete loss when it comes to combining them and making them work together.
My questions are as follows:
Does the button in the HTML page come inside a tag (like we would normally do in a CGI-based program)? If yes, what file does that call? If no, then how do I pass the values to be added?
What is the order of execution of the 3 Perl files? Which one calls which one? How is the flow of execution?
When I tried to run the perl files from the CLI, i.e using $./test2.pl, I got the following error: Error 301 Moved Permanently. What moved permanently? which file was it trying to access? I tried running the files from withing /var/www/html and /var/www/html/test.
Some help in understanding the nuances of this would really be appreciated. Thanks in advance
Does the button in the HTML page come inside a tag (like we would
*normally do in a CGI-based program)? If yes, what file does that call?*
If no, then how do I pass the values to be added?
HTML has nothing at all to do with JSON-RPC. While the RPC call is done via an HTTP POST request, if you're doing that from the browser, you'll need to use XMLHttpRequest (i.e: AJAX). Unlink an HTML form post the Content-encoding: header will need to be something specific to JSON-RPC (e.g: application/json or similar), and you'll need to encode your form data via JSON.stringify and correctly construct the JSON-RPC "envelope", including the id, jsonrpc, method and params properties.
Rather than doing this by hand you might use a purpose-build JSON-RPC JavaScript client like the jQuery-JSONRP plugin (there are many others) -- although the protocol is so simple that implementations usually are less than 20 lines of code.
From the jQuery-RPC documentation, you'd set up the connection like this:
$.jsonRPC.setup({
endPoint: '/ENDPOINT-ROUTE-GOES-HERE'
});
and you'd call the server-side method like this:
$.jsonRPC.request('sum', {
params: [YOURNUMBERINPUTELEMENT1.value, YOURNUMBERINPUT2.value],
success: function(result) {
/* Do something with the result here */
},
error: function(result) {
/* Result is an RPC 2.0 compatible response object */
}
});
What is the order of execution of the 3 Perl files? Which one calls
*which one? How is the flow of execution?*
You'll likely only need test2.pl for testing. It's an example implementation of a JSON-RPC client. You likely want your client to run in your web-browser (as described above). The client JavaScript will make an HTTP POST request to wherever test1.pl is serving content. (e.g: http://localhost:8080).
Or, if you want to keep your code as HTML<-->CGI, then you'll need to make JSON-RPC client calls from within your Perl CGI server-side code (which seems silly if it's on the same machine).
When test1.pl calls dispatch, the MyApp module will be loaded.
Then, when test1.pl calls handle, the sum function in the MyApp package will be called.
The JSON::RPC::Server module takes care of marshalling from JSON-RPC to perl datastructures and back again around the call to handle. die()ing in sum should result in a JSON-RPC exception being transmitted to the calling client, rather than death of the test1.pl script.
When I tried to run the perl files from the CLI, i.e using
*$./test2.pl, I got the following error: Error 301 Moved Permanently.*
What moved permanently? which file was it trying to access? I tried
*running the files from withing /var/www/html and /var/www/html/test.*
This largely depends the configuration of your machine. There's nothing obvious (in your code) to suggest that a 301 Moved Permanently would be issued in response to a valid JSON-RPC request.
I am working on something to interact with Amazon's REST API, but I keep getting an error in my response that points to a mal-formed request. I don't see any errors in the code (the parameter that it says is missing is clearly there), so I want to see the raw request that is being sent.
I don't see any available method that will let me do this. Maybe a server that will just include my request as its response?
Create your own endpoint that will echo to the screen your request. For example, to echo a GET request, send it to a script like this (that's been Publish > Deploy as web app):
function doGet(e) {
var test = 'Echo at ' + new Date() + '\n' + e.queryString;
return ContentService.createTextOutput(test);
}
A little late to the game (10 years) but you can now do this:
const requestResult = UrlFetchApp.getRequest(url, options);
Run it in debug mode and break after this executes to examine requestResult.
See: https://developers.google.com/apps-script/reference/url-fetch/url-fetch-app#getrequesturl,-params for an official description and a full explanation of the properties for the options parameter.