In Darts API, the method
element.setCustomValidity(num message)
has a number as the argument. I was expecting the type of the message to be a String. Is this an error?
I created an issue https://github.com/Polymer/core-input/issues/41
The Dart element uses information from JS comments to generate type annotations and the comment in the JavaScript element contains the wrong type information.
As a workaround you can call the JS function directly:
void setCustomValidity(CoreInput inp, String message) {
inp.jsElement.callMethod('setCustomValidity', ["Give me more!"]);
}
see also Taking total control of PaperInput validation
Related
I am implementing a Pub/Sub to BigQuery pipeline. It looks similar to How to create read transform using ParDo and DoFn in Apache Beam, but here, I have already a PCollection created.
I am following what is described in the Apache Beam documentation to implement a ParDo operation to prepare a table row using the following pipeline:
static class convertToTableRowFn extends DoFn<PubsubMessage, TableRow> {
#ProcessElement
public void processElement(ProcessContext c) {
PubsubMessage message = c.element();
// Retrieve data from message
String rawData = message.getData();
Instant timestamp = new Instant(new Date());
// Prepare TableRow
TableRow row = new TableRow().set("message", rawData).set("ts_reception", timestamp);
c.output(row);
}
}
// Read input from Pub/Sub
pipeline.apply("Read from Pub/Sub",PubsubIO.readMessagesWithAttributes().fromTopic(topicPath))
.apply("Prepare raw data for insertion", ParDo.of(new convertToTableRowFn()))
.apply("Insert in Big Query", BigQueryIO.writeTableRows().to(BQTable));
I found the DoFn function in a gist.
I keep getting the following error:
The method apply(String, PTransform<? super PCollection<PubsubMessage>,OutputT>) in the type PCollection<PubsubMessage> is not applicable for the arguments (String, ParDo.SingleOutput<PubsubMessage,TableRow>)
I always understood that a ParDo/DoFn operations is a element-wise PTransform operation, am I wrong ? I never got this type of error in Python, so I'm a bit confused about why this is happening.
You're right, ParDos are element-wise transforms and your approach looks correct.
What you're seeing is the compilation error. Something like this happens when the argument type of the apply() method that was inferred by java compiler doesn't match the type of the actual input, e.g. convertToTableRowFn.
From the error you're seeing it looks like java infers that the second parameter for apply() is of type PTransform<? super PCollection<PubsubMessage>,OutputT>, while you're passing the subclass of ParDo.SingleOutput<PubsubMessage,TableRow> instead (your convertToTableRowFn). Looking at the definition of SingleOutput your convertToTableRowFn is basically a PTransform<PCollection<? extends PubsubMessage>, PCollection<TableRow>>. And java fails to use it in apply where it expects PTransform<? super PCollection<PubsubMessage>,OutputT>.
What looks suspicious is that java didn't infer the OutputT to PCollection<TableRow>. One reason it would fail to do so if you have other errors. Are you sure you don't have other errors as well?
For example, looking at convertToTableRowFn you're calling message.getData() which doesn't exist when I'm trying to do it and it fails compilation there. In my case I need to do something like this instead: rawData = new String(message.getPayload(), Charset.defaultCharset()). Also .to(BQTable)) expects a string (e.g. a string representing the BQ table name) as an argument, and you're passing some unknown symbol BQTable (maybe it exists in your program somewhere though and this is not a problem in your case).
After I fix these two errors your code compiles for me, apply() is fully inferred and the types are compatible.
I'm debugging an app, but I need to know some values in the fly, I was wondering if there's a way to print a message in console like console.log using Javascript.
I appreciate the help.
print() is probably what you are looking for. Here's some more info on debugging in flutter.
You can use
print()
function or
debugPrint()
The debugPrint() function can print large outputs.
There are more helpful methods in import 'dart:developer' library and one of them is log().
example:
int i = 5;
log("Index number is: $i");
//output
[log] Index number is: 5
void log(String message, {DateTime time, int sequenceNumber, int level
= 0, String name = '', Zone zone, Object error, StackTrace stackTrace})
Emit a log event.
This function was designed to map closely to the logging information
collected by package:logging.
[message] is the log message
[time] (optional) is the timestamp
[sequenceNumber] (optional) is a monotonically increasing sequence number
[level] (optional) is the severity level (a value between 0 and 2000); see the package:logging Level class for an overview of the
possible values
[name] (optional) is the name of the source of the log message
[zone] (optional) the zone where the log was emitted
[error] (optional) an error object associated with this log event
[stackTrace] (optional) a stack trace associated with this log event
Read more.:
print() is from dart:core and its implementation:
/// Prints a string representation of the object to the console.
void print(Object object) {
String line = "$object";
if (printToZone == null) {
printToConsole(line);
} else {
printToZone(line);
}
}
debugPrint():
/// Prints a message to the console, which you can access using the "flutter"
/// tool's "logs" command ("flutter logs").
///
/// If a wrapWidth is provided, each line of the message is word-wrapped to that
/// width. (Lines may be separated by newline characters, as in '\n'.)
///
/// By default, this function very crudely attempts to throttle the rate at
/// which messages are sent to avoid data loss on Android. This means that
/// interleaving calls to this function (directly or indirectly via, e.g.,
/// [debugDumpRenderTree] or [debugDumpApp]) and to the Dart [print] method can
/// result in out-of-order messages in the logs
// read more here: https://api.flutter.dev/flutter/foundation/debugPrint.html
DebugPrintCallback debugPrint = debugPrintThrottled;
/// Alternative implementation of [debugPrint] that does not throttle.
/// Used by tests.
debugPrintSynchronously(String message, { int wrapWidth })
/// Implementation of [debugPrint] that throttles messages. This avoids dropping
/// messages on platforms that rate-limit their logging (for example, Android).
void debugPrintThrottled(String message, { int wrapWidth })
Read more.
Note that only the print() is taking any type and print to the console. debugPrint() and log() only take String. So, you have to add .toString() or use string interpolation like I shown in provided example snippet.
I tend to do something similar to this
Foo foo;
try{
foo = _someMethod(); //some method that returns a new object
} catch (e) {
print('_someMethod: Foo Error ${foo.id} Error:{e.toString()}'); /*my custom error print message. You don't need brackets if you are printing a string variable.*/
}
Use debug print to avoid logging in production application.
debugPrint("Message");
You can also disable or change debug print implementation in main.dart or any other file like this:
debugPrint = (String message, {int wrapWidth})
{
debugPrintThrottled(message);//Or another other custom code
};
print, debugPrint and others have got some word limit restrictions, if you have something long to print on console, you can:
Create this method:
void printWrapped(String text) {
final pattern = RegExp('.{1,800}'); // 800 is the size of each chunk
pattern.allMatches(text).forEach((match) => print(match.group(0)));
}
Usage:
printWrapped("Your very long string ...");
Source
One more answer for Concatenate with String:
// Declaration
int number = 10;
//Button Action
RaisedButton(
child: Text("Subtract Me"),
onPressed: () {
number = number - 1;
print('You have got $number as result');
print('Before Value is ${number - 1} and After value is ${number + 1}');
},
),
//Output:
flutter: You have got 9 as result
flutter: Before Value is 8 and After value is 10
debugPrint()
Might as well use rather than print() as it attempts to reduce log line drop or being out of order on Android kernel
Refs:
Logging in Flutter
I think this might help you, because, I was also got stuck in many ways of knowing the output of my code in the dart file, hence I got the solution by following the steps, shown in the video.
https://www.youtube.com/watch?v=hhP1tE-IHos
here I have shown an instance of how it works after following the video.
check the left side column where it shows about the value which profile variable carry i.e., null
you can simply use print('whatever you want to print') same as console.log() in javascript.
for more info you can check here.
Note that the print() and log() options both add their own labels at the start of the line, and apply additional formatting that can cause long lines to be truncated. In the case of a dart:io app, you can bypass this interception and mangling entirely by going directly to stdout/stderr, etc. as in stdout.write(), stdout.writeln(), etc. Likewise if you are looking to log explicitly to one or the other. I ran into this issue when adding CLI args to a flutter application.
I use something like this. The print() function can print data up to some limit. So I use this log.
import 'dart:developer';
debugLog({String tag = '', required dynamic value}) {
log("TAG $tag : ${value.toString()}");
}
I want to read the error messages from messages file but I am unable to. What mistake am I making?
The code where I want to read the string from messages file is
Future { Ok(Json.toJson(JsonResultError(messagesApi("error.incorrectBodyType")(langs.availables(0))))) }
The messages file error.incorrectBodyType=Incorrect body type. Body type must be JSON
The messagesApi("error.incorrectBodyType") should return Incorrect body type. Body type must be JSON but it returns error.incorrectBodyType.
If I remove double quotes in messagesApi(error.incorrectBodyType) then the code doesn't compile
Update
I added a couple of debug prints and notice that the keys I am using in MessagesApi are not defined. I don't know why though as I have created them in messages file.
println("langs array"+langs.availables)
println("app.title"+messagesApi.isDefinedAt("app.title")(langs.availables(0)))
println("error"+messagesApi.isDefinedAt("error.incorrectBodyType")(langs.availables(0)))
prints
langs arrayList(Lang(en_GB))
app.titlefalse
errorfalse
Update 2
I might have found the issue but I don't know how to resolve it. Basically, I am running my test case without an instance of the Application. I am mocking messagesApi by calling stubMessagesApi() defined in Helpers.stubControllerComponents, If I run the same code using an Application eg class UserControllerFunctionalSpec extends PlaySpec with OneAppPerSuiteWithComponents then app.title and error are defined. It seems without an instance of Application, MessagesApi is not using the messages file.
I was able to solve the issue by creating a new instance of MessagesApi using DefaultMessagesApi
val messagesApi = new DefaultMessagesApi( //takes map of maps. the first is the language file, the 2nd is the map between message title and description
Map("en" -> //the language file
Map("error.incorrectBodyType" -> "Incorrect body type. Body type must be JSON") //map between message title and description
)
)
val controller = new UserController(mockUserRepository,mockControllerComponents,mockSilhouette,messagesApi,stubLangs())
When I define a spinner in ScalaJS and handle the spin value I am not able to get the new spin value in the event as I would have expected. According to the JQuery UI documentation the second parameter to the spin event is the ui object that contains a value attribute. So I defined a trait:
trait Number extends js.Object {
val value: Int = js.native
}
And then handle my spin event thus:
jQuery("#mySpinner").spinner(js.Dynamic.literal(spin = { (e: HTMLInputElement, ui: Number) =>
log("Change: " + ui.value)
}: js.ThisFunction1[HTMLInputElement, Number, Any]))
But the "value" attribute does not seem to be a member of the ui object as I get the exception below in my log statement. Can someone tell me what I am doing wrong?
uncaught exception: scala.scalajs.runtime.UndefinedBehaviorError: An
undefined behavior was detected: undefined is not an instance of
java.lang.Integer
You say e: HTMLInputElement but it should be e: Event
I suspect the problem is a combination of the previous comments. You are correct that, since you're using ThisFunction, the first element should be an Element of some sort. (Although, is it really an HTMLInputElement? That's a slightly unusual element type to put a spinner on.)
But that Element gets prepended to the function parameters, whereas you've got it replacing one.
In other words, you have
(e: HTMLInputElement, ui: Number)
but it needs to be
(elem: HTMLInputElement, e:Event, ui: Number)
in order to match the expected signature. So in practice, the system is trying to cast the value member of an Event, which of course doesn't exist, to Integer. It finds that value is undefined, tries to cast it to Integer, and boom.
I can't say I'm 100% certain (and IMO that ui parameter is just plain weird to begin with -- I'm a little suspicious of the jQueryUI documentation there), but that's my guess. Try fixing the signature of your call, and see if the error goes away...
I made a custom component which basically wraps a d3 line chart. Now I want to be able to register a callback for clicks on the lines in the chart.
I gave the component a #NgCallback parameter, which I then send events to:
class NetworkSummaryComponent implements NgShadowRootAware {
#NgCallback('callback')
Function callback;
void onShadowRoot(ShadowRoot shadowRoot) {
...
chart.callMethod('listen', ['line-click', (ev) {
var name = ev.callMethod('getLineName');
print(name);
callback({'name': name});
}]);
}
}
When using the component, I specify a function of my controller as callback:
<network-summary
...
callback="ctrl.lineClicked">
</network-summary>
However, that function is never actually called, put I know the callback arrives from the JS side because the print in the first snippet is executed.
If I instead specify the attribute as callback="ctrl.lineClicked()" I get a strange exception:
Closure call with mismatched arguments: function 'call'
I could not find any official documentation on how to properly do callbacks, so I'm not exactly sure what I'm doing wrong.. Any ideas?
It turns out that I had to explicitly name the expected arguments in the attributes:
<network-summary
...
callback="ctrl.lineClicked(name)">
</network-summary>
Hope this is useful to the next person having this problem.