I would like to create UUID from a string so that I can generate the same UUID for the particular string input. This SO tells how to do it in Java, but is there any way to achieve it in QT5?
From the documentation here and here the following java...
// Java
String aString="JUST_A_TEST_STRING";
String result = UUID.nameUUIDFromBytes(aString.getBytes()).toString();
uses UUID.nameUUIDFromBytes to generate a type 3 MD5 digest based UUID from the byte data supplied.
The equivalent C++ using QUuid is, I think...
// C++
QString aString("JUST_A_TEST_STRING");
QString result = QUuid::createUuidV3(QUuid{}, aString).toString();
Related
How can I find user public address from his private key ?
Already I found a way to convert public to hex Address also private to hex and reverse
but get stuck in this one !
Using TronWeb, you can call this function:
const address = tronWeb.address.fromPrivateKey(newAccount.privateKey);
That code comes from one of TronWeb's tests
for bitcoin you need use this package to find public key => dart_wif
print('hex :::::: ${HEX.encode(index.privateKey!)}');
WIF decoded = WIF(version: 128, privateKey: index.privateKey!, compressed: true);
String key = wif.encode(decoded);
print(key);
If you are using python, the official tronpy document doesn't mentioned this. However, you can find the answer by yourself.
Open ipython from terminal, create a key object from a random key, input the key variable name and press tab twice, you will see all the attributes and functions of the object.
import tronpy
my_random_key = tronpy.keys.PrivateKey.random()
my_key = tronpy.keys.PrivateKey.fromhex(my_random_key)
my_key.public_key.to_base58check_address()
In Vaadin 8 Framework, and Vaadin 10 Flow, the data-binding capability lets us provide a Converter to mediate between the widget’s expected data type (such as String for a TextField) and the data type of the backing bean property (such as Integer number).
In this example, the built-in Converter implementation StringToIntegerConverter is used.
binder
.forField( this.phaseField )
.withConverter(
new StringToIntegerConverter( "Must enter an integer number" )
)
.bind( Panel::getPhase , Panel::setPhase ) ;
But what about defining a Converter for other types? How can I easily define a short-and-sweet Converter? For example, a String-to-UUID converter. I want to show the canonical 36-character hex string in a TextField, and going the other direction, parse that string back into a UUID.
// String to UUID
UUID uuid = UUID.fromString( myString ) ;
// UUID to String
String myString = uuid.toString() ;
I see that Binder.BindingBuilder offers the pair of methods withConverter that both take a pair of SerializableFunction objects.
Binder.BindingBuilder::withConverter(SerializableFunction<TARGET,NEWTARGET> toModel, SerializableFunction<NEWTARGET,TARGET> toPresentation)
Binder.BindingBuilder::withConverter(SerializableFunction<TARGET,NEWTARGET> toModel, SerializableFunction<NEWTARGET,TARGET> toPresentation, String errorMessage)
➥ So how do I define the pair of SerializableFunction objects/classes?
I noticed that this interface lists a known subinterface ValueProvider<SOURCE,TARGET>. That looks familiar, and I have a hunch it is the key to easily defining a short simple converter. But I do not quite comprehend the syntax with lambdas and all that is going on here.
I am not asking how to write a class implementing Converter. I am asking how to write the pair of SerializableFunction arguments to pass to the Binder.BindingBuilder::withConverter methods listed above as bullet items.
Quoting that JavaDoc:
Interface Binder.BindingBuilder<BEAN,TARGET>
…
withConverter
default <NEWTARGET> Binder.BindingBuilder<BEAN,NEWTARGET> withConverter(SerializableFunction<TARGET,NEWTARGET> toModel, SerializableFunction<NEWTARGET,TARGET> toPresentation)
Maps the binding to another data type using the mapping functions and a possible exception as the error message.
The mapping functions are used to convert between a presentation type, which must match the current target data type of the binding, and a model type, which can be any data type and becomes the new target type of the binding. When invoking bind(ValueProvider, Setter), the target type of the binding must match the getter/setter types.
For instance, a TextField can be bound to an integer-typed property using appropriate functions such as: withConverter(Integer::valueOf, String::valueOf);
Type Parameters:
NEWTARGET - the type to convert to
Parameters:
toModel - the function which can convert from the old target type to the new target type
toPresentation - the function which can convert from the new target type to the old target type
Returns:
a new binding with the appropriate type
Throws:
IllegalStateException - if bind has already been called
You can do it by passing two lambda expressions to withConverter, so something like this:
binder.forField(textField)
.withConverter(text -> UUID.fromString(text), uuid -> uuid.toString())
.bind(/* ... */);
If you need a more complicated conversion, then the right-hand side of the lambda can be surrounded with brackets, e.g.
binder.forField(textField).withConverter( text -> {
if ( text == null ) {
return something;
} else {
return somethingElse;
}
}, uuid -> { return uuid.toString(); } )
.bind(/* ... */);
If you need your converter multiple times, I recommend creating a separate class implementing interface com.vaadin.data.Converter. However, using lambdas is possible, too, as you already know (see answer of #ollitietavainen). But this is not Vaadin specific, it's a Java 8+ feature you can read about e.g. here. Basically, you can use lambdas whereever an object implementing an interface with only one method is required.
I receive data in JSON using a QJsonObject. I also have a QObject-based object holding properties, using Q_PROPERTY(...), for the keys in the JSON. Since Qt now has some more datatypes than JSON how can one check if they are convertible.
The datatypes used in the object typically are one of the following but not limited to
uint
double
QString
QDateTime
bool
The idea is to automatically call setProperty(...) on the QOject derived object for every key/value in the QJsonObject. Since this could fail due to malformed input in the JSON I have to check validity based on the QMetaProperty and QJsonObject/QVariantMap data.
Since this should run generic as a base class implementing manual checks for every datatype fails. I know there is QVariant::isConvertible<T>().
#include <QJsonObject>
#include <QVariant>
#include <QMetaObject>
#include <QMetaProperty>
class Test {
Q_GADGET
Q_PROPERTY(QString test)
QString m_test;
QJsonObject jo;
void call();
}
void Test::call()
{
jo.insert("test",QJsonValue(5));
// This will fail, since int is not convertible to QString implicitly
staticMetaObject->property(staticMetaObject->propertyOffset()).writeOnGadget(this,jo["test"].toVariant());
}
Since I am parsing the JSON before to check if every property would have a corresponding key in the JSON-Object I really like to catch these there already without changing my original object. Something like:
jo["test"].toVariant().canConvert<staticMetaObject->property(staticMetaObject->propertyOffset()).type()>()
Instead of using templated bool QVariant::canConvert<T>() one can use bool QVariant::canConvert(int targetTypeId).
QMetaProperty po = staticMetaObject->property(staticMetaObject->propertyOffset());
jo["test"].toVariant().canConvert(po.type());
I have multiple documents to parse and I need access to all the document objects for the lifetime of the creating class. How do I create an array of xml_document pointers as a member variable?
I've tried creating a single member variable as follows:
private:
rapidxml::xml_document<> *m_pDoc; // doesn't compile
error: name followed by "::" must be a class or namespace name
I'm sure this is because the template class isn't well defined but I'm not sure how to properly define the pointer.
That compiles fine for me. The error message implies you've forgotten this, maybe?
#include "rapidxml.hpp"
Rapidxml references to the pointers of your vector buffer every time you pass an xml. So store both your buffers and also the xml_document<> docs.
Put the filepaths of your xml docs
char *XMLFilePaths[numXmlDocs] = {"../PersonDatasetA/xmlFile.xml","../PersonDatasetB/xmlFile.xml"};
Store both the buffers and also the xml documents into arrays
std::array<vector<char>,numXmlDocs> XMLDocBuffers;
std::array<xml_document<>,numXmlDocs> XMLDocs;
//For each xml doc, read and store it in an array
for(int i=0;i<numXmlDocs;i++){
//Parse each xml into the buffer array
char xmlFileName[100] ;
sprintf(xmlFileName,"%s",XMLFilePaths[i]);
ifstream theFile (xmlFileName);
vector<char> buffer((istreambuf_iterator<char>(theFile)), istreambuf_iterator<char>());
buffer.push_back('\0');
//Store the buffer
XMLDocBuffers[i] = buffer;
// Parse the buffer usingthe xml file parsing library into doc
XMLDocs[i].parse<0>(&(XMLDataset_StringDocs[i][0]));
xml_node<> *root_node; // Find the root node
root_node = (XMLDocs[i]).first_node(typesOfSamples);
I am working on a website to manage active directory. I want to check that whether user has permission to change password or not. So I have to find "ntSecurityDescriptor" property value after that I have to cast it into IADsSecurityDescriptor.
Now if I use DirectorySearcher class then property value is of type System._ComObject and easily casted to IADsSecurityDescriptor. But when I use LdapConnection and SearchResponse I get property value of type.
byte[] array which is unale to cast to IADsSecityDescriptor.
I am getting error
Unable to cast System.Byte[] to IADsSecurityDescriptor
Is there some problem with SearchResponse or I have use some kind of casting technique to achieve this? I have some problem to use DirectoryEntry class so I can only use LdapConnction class.
At last I find the answer of my question. This class convert the byte[] to valid security decriptor comobject.
ActiveDs.ADsSecurityUtility secUtility = new ActiveDs.ADsSecurityUtility();
ActiveDs.IADsSecurityDescriptor sd = (IADsSecurityDescriptor)secUtility.ConvertSecurityDescriptor((byte[])attribute[0], (int)ADS_SD_FORMAT_ENUM.ADS_SD_FORMAT_RAW, (int)ADS_SD_FORMAT_ENUM.ADS_SD_FORMAT_IID);
I think you should put your effort in trying to use the DirectoryEntry method.
You will have very hard times trying to manipulate AD objects with LdapConnection.
If you want to continue the Ldap way, after a quick search, I would give a try to the native (this word says it all) autorization functions. There seems to be interesting things in there, like :
ConvertStringSecurityDescriptorToSecurityDescriptor
http://msdn.microsoft.com/en-us/library/windows/desktop/aa376401%28v=vs.85%29.aspx
C# syntax
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("Advapi32.dll", CharSet=CharSet.Unicode, SetLastError=true)]
internal static extern bool ConvertStringSecurityDescriptorToSecurityDescriptor(string StringSecurityDescriptor, uint StringSDRevision, ref IntPtr SecurityDescriptor, IntPtr SecurityDescriptorSize);