Undefined Symbols error when integrating Apptentive iOS SDK via Cocoapods
We have found that adding the Apptentive cocoa pod to an existing Xcode project may potentially not include some of our required frameworks.
Check your linker flags:
Target > Build Settings > Other Linker Flags
You should see -lApptentiveConnect
listed as a linker flag:
... -ObjC -lApptentiveConnect ...
You should also see our required Frameworks listed:
strange error in my Animation Drawable
Looks like whatever is in your Animation Drawable definition is too much memory to decode and sequence. The idea is that it loads up all the items and make them in an array and swaps them in and out of the scene according to the timing specified for each frame.
If this all can't fit into memory, it's probably better to either do this on your own with some sort of handler or better yet just encode a movie with the specified frames at the corresponding images and play the animation through a video codec.
Android Gradle 5.0 Update:Cause: org.jetbrains.plugins.gradle.tooling.util
This issue is due to incompatible of your plugin Verison and required Gradle version; they need to match with each other. I am sharing how my problem was solved.
plugin version
Required Gradle version is here
more compatibility you can see from here.
Android Plugin for Gradle Release Notes
if you have the android studio version 4.0.1
then your top level gradle file must be like this
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:4.0.2'
classpath 'com.google.firebase:firebase-crashlytics-gradle:2.4.1'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
and the gradle version should be
and your app gradle look like this
Execution failed for task ':app:compileDebugJavaWithJavac' Android Studio 3.1 Update
Not sure if this solution works for you or not but just want to heads you up on compiler and build tools version compatibility issues.
This could be because of Java and Gradle version mismatch.
distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip
Gradle 4.4 is compatible with only Java 7 and 8. So, point your global variable JAVA_HOME to Java 7 or 8.
In mac, add below line to your ~/.bash_profile
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home
You can have multiple java versions. Just change the JAVA_HOME path based on need. You can do it easily, check this
No converter found capable of converting from type to type
Turns out, when the table name is different than the model name, you have to change the annotations to:
@Entity
@Table(name = "table_name")
class WhateverNameYouWant {
...
Instead of simply using the @Entity annotation.
What was weird for me, is that the class it was trying to convert to didn't exist. This worked for me.
Kotlin Android start new Activity
This is my main activity where i take the username and password from edit text and setting to the intent
class MainActivity : AppCompatActivity() {
val userName = null
val password = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
button.setOnClickListener {
val intent = Intent(this@MainActivity,SecondActivity::class.java);
var userName = username.text.toString()
var password = password_field.text.toString()
intent.putExtra("Username", userName)
intent.putExtra("Password", password)
startActivity(intent);
}
}
This is my second activity where i have to receive values from the main activity
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_second)
var strUser: String = intent.getStringExtra("Username")
var strPassword: String = intent.getStringExtra("Password")
user_name.setText("Seelan")
passwor_print.setText("Seelan")
}
Android Room - simple select query - Cannot access database on the main thread
You can allow database access on the main thread but only for debugging purpose, you shouldn't do this on production.
Here is the reason.
Note: Room doesn't support database access on the main thread unless you've called allowMainThreadQueries() on the builder because it might lock the UI for a long period of time. Asynchronous queries—queries that return instances of LiveData or Flowable—are exempt from this rule because they asynchronously run the query on a background thread when needed.
org.springframework.web.client.HttpClientErrorException: 400 Bad Request
This is what worked for me. Issue is earlier I didn't set Content Type(header) when I used exchange method.
MultiValueMap<String, String> map = new LinkedMultiValueMap<String, String>();
map.add("param1", "123");
map.add("param2", "456");
map.add("param3", "789");
map.add("param4", "123");
map.add("param5", "456");
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
final HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<MultiValueMap<String, String>>(map ,
headers);
JSONObject jsonObject = null;
try {
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> responseEntity = restTemplate.exchange(
"https://url", HttpMethod.POST, entity,
String.class);
if (responseEntity.getStatusCode() == HttpStatus.CREATED) {
try {
jsonObject = new JSONObject(responseEntity.getBody());
} catch (JSONException e) {
throw new RuntimeException("JSONException occurred");
}
}
} catch (final HttpClientErrorException httpClientErrorException) {
throw new ExternalCallBadRequestException();
} catch (HttpServerErrorException httpServerErrorException) {
throw new ExternalCallServerErrorException(httpServerErrorException);
} catch (Exception exception) {
throw new ExternalCallServerErrorException(exception);
}
ExternalCallBadRequestException and ExternalCallServerErrorException are the custom exceptions here.
Note: Remember HttpClientErrorException is thrown when a 4xx error is received. So if the request you send is wrong either setting header or sending wrong data, you could receive this exception.
java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient
I did below modifications and I am able to start the Hive Shell without any errors:
1. ~/.bashrc
Inside bashrc file add the below environment variables at End Of File : sudo gedit ~/.bashrc
#Java Home directory configuration
export JAVA_HOME="/usr/lib/jvm/java-9-oracle"
export PATH="$PATH:$JAVA_HOME/bin"
# Hadoop home directory configuration
export HADOOP_HOME=/usr/local/hadoop
export PATH=$PATH:$HADOOP_HOME/bin
export PATH=$PATH:$HADOOP_HOME/sbin
export HIVE_HOME=/usr/lib/hive
export PATH=$PATH:$HIVE_HOME/bin
2. hive-site.xml
You have to create this file(hive-site.xml) in conf directory of Hive and add the below details
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
<name>javax.jdo.option.ConnectionURL</name>
<value>jdbc:mysql://localhost/metastore?createDatabaseIfNotExist=true</value>
</property>
<property>
<name>javax.jdo.option.ConnectionDriverName</name>
<value>com.mysql.jdbc.Driver</value>
</property>
<property>
<name>javax.jdo.option.ConnectionUserName</name>
<value>root</value>
</property>
<property>
<name>javax.jdo.option.ConnectionPassword</name>
<value>root</value>
</property>
<property>
<name>datanucleus.autoCreateSchema</name>
<value>true</value>
</property>
<property>
<name>datanucleus.fixedDatastore</name>
<value>true</value>
</property>
<property>
<name>datanucleus.autoCreateTables</name>
<value>True</value>
</property>
</configuration>
3. You also need to put the jar file(mysql-connector-java-5.1.28.jar) in the lib directory of Hive
4. Below installations required on your Ubuntu to Start the Hive Shell:
- MySql
- Hadoop
- Hive
- Java
5. Execution Part:
Start all services of Hadoop: start-all.sh
Enter the jps command to check whether all Hadoop services are up and running: jps
Enter the hive command to enter into hive shell: hive
Difference between `Optional.orElse()` and `Optional.orElseGet()`
Short Answer:
- orElse() will always call the given function whether you want it or not, regardless of
Optional.isPresent()
value
- orElseGet() will only call the given function when the
Optional.isPresent() == false
In real code, you might want to consider the second approach when the required resource is expensive to get.
// Always get heavy resource
getResource(resourceId).orElse(getHeavyResource());
// Get heavy resource when required.
getResource(resourceId).orElseGet(() -> getHeavyResource())
For more details, consider the following example with this function:
public Optional<String> findMyPhone(int phoneId)
The difference is as below:
X : buyNewExpensivePhone() called
+——————————————————————————————————————————————————————————————————+——————————————+
| Optional.isPresent() | true | false |
+——————————————————————————————————————————————————————————————————+——————————————+
| findMyPhone(int phoneId).orElse(buyNewExpensivePhone()) | X | X |
+——————————————————————————————————————————————————————————————————+——————————————+
| findMyPhone(int phoneId).orElseGet(() -> buyNewExpensivePhone()) | | X |
+——————————————————————————————————————————————————————————————————+——————————————+
When optional.isPresent() == false
, there is no difference between two ways. However, when optional.isPresent() == true
, orElse()
always calls the subsequent function whether you want it or not.
Finally, the test case used is as below:
Result:
------------- Scenario 1 - orElse() --------------------
1.1. Optional.isPresent() == true (Redundant call)
Going to a very far store to buy a new expensive phone
Used phone: MyCheapPhone
1.2. Optional.isPresent() == false
Going to a very far store to buy a new expensive phone
Used phone: NewExpensivePhone
------------- Scenario 2 - orElseGet() --------------------
2.1. Optional.isPresent() == true
Used phone: MyCheapPhone
2.2. Optional.isPresent() == false
Going to a very far store to buy a new expensive phone
Used phone: NewExpensivePhone
Code:
public class TestOptional {
public Optional<String> findMyPhone(int phoneId) {
return phoneId == 10
? Optional.of("MyCheapPhone")
: Optional.empty();
}
public String buyNewExpensivePhone() {
System.out.println("\tGoing to a very far store to buy a new expensive phone");
return "NewExpensivePhone";
}
public static void main(String[] args) {
TestOptional test = new TestOptional();
String phone;
System.out.println("------------- Scenario 1 - orElse() --------------------");
System.out.println(" 1.1. Optional.isPresent() == true (Redundant call)");
phone = test.findMyPhone(10).orElse(test.buyNewExpensivePhone());
System.out.println("\tUsed phone: " + phone + "\n");
System.out.println(" 1.2. Optional.isPresent() == false");
phone = test.findMyPhone(-1).orElse(test.buyNewExpensivePhone());
System.out.println("\tUsed phone: " + phone + "\n");
System.out.println("------------- Scenario 2 - orElseGet() --------------------");
System.out.println(" 2.1. Optional.isPresent() == true");
// Can be written as test::buyNewExpensivePhone
phone = test.findMyPhone(10).orElseGet(() -> test.buyNewExpensivePhone());
System.out.println("\tUsed phone: " + phone + "\n");
System.out.println(" 2.2. Optional.isPresent() == false");
phone = test.findMyPhone(-1).orElseGet(() -> test.buyNewExpensivePhone());
System.out.println("\tUsed phone: " + phone + "\n");
}
}
HikariCP - connection is not available
From stack trace:
HikariPool: Timeout failure pool HikariPool-0 stats (total=20, active=20, idle=0, waiting=0)
Means pool reached maximum connections limit set in configuration.
The next line:
HikariPool-0 - Connection is not available, request timed out after 30000ms.
Means pool waited 30000ms for free connection but your application not returned any connection meanwhile.
Mostly it is connection leak (connection is not closed after borrowing from pool),
set leakDetectionThreshold to the maximum value that you expect SQL query would take to execute.
otherwise,
your maximum connections 'at a time' requirement is higher than 20 !
ld: framework not found Pods
This happened to me after updating my Podfile and doing a pod update.
For some reason, I had a "Pods_[ProjectName]".framework file appear under my project under 'Targets' > General > Linked Frameworks and Libraries.
Deleting this and then clean/rebuilding fixed the issue.
Error inflating class android.support.v7.widget.Toolbar?
It is unclearly why this error happened with me but I solved. I used same layout, in-line or using include, both of them cause NPE error. So I think it's not layout issue.
I had an abstract class call BaseActivity extends ActionBarActivity which have initActionBar() method. I override and call this method in OnCreate of child class. Something like that:
android.support.v7.app.ActionBar mActionBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_book_appointment);
// Inject View using ButterKnife
ButterKnife.inject(this);
// Init toolbar & status bar
initActionBar();
}
@Override
protected void initActionBar() {
super.initActionBar();
setSupportActionBar(mToolBar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mActionBar = getSupportActionBar();
mActionBar.setDisplayHomeAsUpEnabled(true);
mActionBar.setHomeButtonEnabled(true);
}
I HAD NPE ERROR WITH ABOVE CODE. I DON'T KNOW WHY I'M WRONG. I SOLVE BY BELOW CODE AND IT'S LOOK SAME.
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_book_appointment);
ButterKnife.inject(this);
setSupportActionBar(mToolBar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mActionBar = getSupportActionBar();
mActionBar.setDisplayHomeAsUpEnabled(true);
mActionBar.setHomeButtonEnabled(true);
initActionBar();
}
@Override
protected void initActionBar() {
super.initActionBar();
}
Duplicate symbols for architecture x86_64 under Xcode
None of above solutions works for me, I just fixed it myself.
I got duplicate symbol of my core data model
which I make it myself, but
in my .xcdatamodeld
inspector, I choose Class Definition
of Codegen
property, I guess that's what's wrong with. Then I choose Manual/None
,it got fixed.
Hope this can be helpful for you!
Swift Beta performance: sorting arrays
TL;DR: Yes, the only Swift language implementation is slow, right now. If you need fast, numeric (and other types of code, presumably) code, just go with another one. In the future, you should re-evaluate your choice. It might be good enough for most application code that is written at a higher level, though.
From what I'm seeing in SIL and LLVM IR, it seems like they need a bunch of optimizations for removing retains and releases, which might be implemented in Clang (for Objective-C), but they haven't ported them yet. That's the theory I'm going with (for now… I still need to confirm that Clang does something about it), since a profiler run on the last test-case of this question yields this “pretty” result:
As was said by many others, -Ofast
is totally unsafe and changes language semantics. For me, it's at the “If you're going to use that, just use another language” stage. I'll re-evaluate that choice later, if it changes.
-O3
gets us a bunch of swift_retain
and swift_release
calls that, honestly, don't look like they should be there for this example. The optimizer should have elided (most of) them AFAICT, since it knows most of the information about the array, and knows that it has (at least) a strong reference to it.
It shouldn't emit more retains when it's not even calling functions which might release the objects. I don't think an array constructor can return an array which is smaller than what was asked for, which means that a lot of checks that were emitted are useless. It also knows that the integer will never be above 10k, so the overflow checks can be optimized (not because of -Ofast
weirdness, but because of the semantics of the language (nothing else is changing that var nor can access it, and adding up to 10k is safe for the type Int
).
The compiler might not be able to unbox the array or the array elements, though, since they're getting passed to sort()
, which is an external function and has to get the arguments it's expecting. This will make us have to use the Int
values indirectly, which would make it go a bit slower. This could change if the sort()
generic function (not in the multi-method way) was available to the compiler and got inlined.
This is a very new (publicly) language, and it is going through what I assume are lots of changes, since there are people (heavily) involved with the Swift language asking for feedback and they all say the language isn't finished and will change.
Code used:
import Cocoa
let swift_start = NSDate.timeIntervalSinceReferenceDate();
let n: Int = 10000
let x = Int[](count: n, repeatedValue: 1)
for i in 0..n {
for j in 0..n {
let tmp: Int = x[j]
x[i] = tmp
}
}
let y: Int[] = sort(x)
let swift_stop = NSDate.timeIntervalSinceReferenceDate();
println("\(swift_stop - swift_start)s")
P.S: I'm not an expert on Objective-C nor all the facilities from Cocoa, Objective-C, or the Swift runtimes. I might also be assuming some things that I didn't write.
Error "library not found for" after putting application in AdMob
If error related to Cocoapods as follow:
library not found for -lPod-...
You need to check Other Linker Flags and remove it from there.
Extra Information: If you have an old project that uses cocoapods. And recently you needed to add the use_frameworks! to your podfile.
cocoapods will not add the libraries to your Other Linker Flags
anymore cause its inherited. Therefore, you may need to remove those
manually from the other linker flags which they were added before
using the use_frameworks!
Xcode - ld: library not found for -lPods
My way
create new project and install pod it will can run without error.
Copy text in "Other Linker Flags" in new project to old project. Make old project to same new project.
Check "Header Search Paths" too.
System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll?
This is not a problem with XAML. The error message is saying that it tried to create an instance of DVRClientInterface.MainWindow
and your constructor threw an exception.
You will need to look at the "Inner Exception" property to determine the underlying cause. It could be quite literally anything, but should provide direction.
An example would be that if you are connecting to a database in the constructor for your window, and for some reason that database is unavailable, the inner exception may be a TimeoutException
or a SqlException
or any other exception thrown by your database code.
If you are throwing exceptions in static constructors, the exception could be generated from any class referenced by the MainWindow
. Class initializers are also run, if any MainWindow
fields are calling a method which may throw.
How to resolve "could not execute statement; SQL [n/a]; constraint [numbering];"?
Overall:You persist entity that is violating database rules like as saving entity that has varchar field over 250 chars ,something like that.
In my case it was a squishy problem with TestEntityManager ,because it use HSQL database /in memory database/ and it persist the user but when you try to find it ,it drops the same exception :/
@RunWith(SpringRunner.class)
@ContextConfiguration(classes= Application.class)
@DataJpaTest
@ActiveProfiles("test")
public class UserServicesTests {
@Autowired
private TestEntityManager testEntityManager;
@Autowired
private UserRepository userRepository;
@Test
public void oops() {
User user = new User();
user.setUsername("Toshko");
//EMAIL IS REQUIRED:
//user.setEmail("OPS");
this.testEntityManager.persist(user);
//HERE COMES TE EXCEPTION BECAUSE THE EMAIL FIELD IN TE DATABASE IS REQUIRED :
this.userRepository.findUserByUsername("Toshko");
System.out.println();
}
}
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException Error
NullPointerException
s are among the easier exceptions to diagnose, frequently. Whenever you get an exception in Java and you see the stack trace ( that's what your second quote-block is called, by the way ), you read from top to bottom. Often, you will see exceptions that start in Java library code or in native implementations methods, for diagnosis you can just skip past those until you see a code file that you wrote.
Then you like at the line indicated and look at each of the objects ( instantiated classes ) on that line -- one of them was not created and you tried to use it. You can start by looking up in your code to see if you called the constructor on that object. If you didn't, then that's your problem, you need to instantiate that object by calling new Classname( arguments ). Another frequent cause of NullPointerException
s is accidentally declaring an object with local scope when there is an instance variable with the same name.
In your case, the exception occurred in your constructor for Workshop on line 75. <init>
means the constructor for a class. If you look on that line in your code, you'll see the line
denimjeansButton.addItemListener(this);
There are fairly clearly two objects on this line: denimjeansButton
and this
. this
is synonymous with the class instance you are currently in and you're in the constructor, so it can't be this
. denimjeansButton
is your culprit. You never instantiated that object. Either remove the reference to the instance variable denimjeansButton
or instantiate it.
Error creating bean with name 'entityManagerFactory
This sounds like a ClassLoader conflict. I'd bet you have the javax.persistence api 1.x on the classpath somewhere, whereas Spring is trying to access ValidationMode
, which was only introduced in JPA 2.0.
Since you use Maven, do mvn dependency:tree
, find the artifact:
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0</version>
</dependency>
And remove it from your setup. (See Excluding Dependencies)
AFAIK there is no such general distribution for JPA 2, but you can use this Hibernate-specific version:
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.0-api</artifactId>
<version>1.0.1.Final</version>
</dependency>
OK, since that doesn't work, you still seem to have some JPA-1 version in there somewhere.
In a test method, add this code:
System.out.println(EntityManager.class.getProtectionDomain()
.getCodeSource()
.getLocation());
See where that points you and get rid of that artifact.
Ahh, now I finally see the problem. Get rid of this:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jpa</artifactId>
<version>2.0.8</version>
</dependency>
and replace it with
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>3.2.5.RELEASE</version>
</dependency>
On a different note, you should set all test libraries (spring-test, easymock etc.) to
<scope>test</scope>
Launching Spring application Address already in use
This error basically happens when the specific port is not free. So there are two solutions, you can free that port by killing or closing the service which is using it or you can run your application (tomcat) on a different port.
Solution 1: Free the port
On a Linux machine you can find the process-id of port's consumer and then kill it. Use the following command (it is assume that the default port is 8080)
netstat -pnltu | grep -i "8080"
The output of the above-mentioned command would be something like:
tcp6 0 0 :::8080 :::* LISTEN 20674/java
Then you can easily kill the process with its processid:
kill 20674
On a windows machine to find a processid use netstat -ano -p tcp |find "8080"
. To kill the process use taskkill /F /PID 1234
(instead of 1234 enter the founded processid).
Solution 2: Change the default port
In the development process developers use the port 8080
that you can change it easily. You need to specify your desired port number in the application.properties
file of your project (/src/main/resources/application.properties
) by using the following specification:
server.port=8081
You can also set an alternative port number while executing the .jar
file
- java -jar spring-boot-application.jar --server.port=8081
Please notice that sometimes (not necessarily) you have to change other ports too like:
management.port=
tomcat.jvmroute=
tomcat.ajp.port=
tomcat.ajp.redirectPort=
etc...
g++ ld: symbol(s) not found for architecture x86_64
I had a similar warning/error/failure when I was simply trying to make an executable from two different object files (main.o and add.o). I was using the command:
gcc -o exec main.o add.o
But my program is a C++ program. Using the g++
compiler solved my issue:
g++ -o exec main.o add.o
I was always under the impression that gcc
could figure these things out on its own. Apparently not. I hope this helps someone else searching for this error.
Spring Data JPA - "No Property Found for Type" Exception
this error happens if you try access un-exists property
my guess is that sorting is done by spring by property name
and not by real column name
.
and the error indicates that, in "UserBoard"
there is no property named "boardId"
.
bests,
Oak
UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only
The answer of Shyam was right. I already faced with this issue before. It's not a problem, it's a SPRING feature. "Transaction rolled back because it has been marked as rollback-only" is acceptable.
Conclusion
- USE REQUIRES_NEW if you want to commit what did you do before exception (Local commit)
- USE REQUIRED if you want to commit only when all processes are done (Global commit) And you just need to ignore "Transaction rolled back because it has been marked as rollback-only" exception. But you need to try-catch out side the caller processNextRegistrationMessage() to have a meaning log.
Let's me explain more detail:
Question: How many Transaction we have? Answer: Only one
Because you config the PROPAGATION is PROPAGATION_REQUIRED so that the @Transaction persist() is using the same transaction with the caller-processNextRegistrationMessage(). Actually, when we get an exception, the Spring will set rollBackOnly for the TransactionManager so the Spring will rollback just only one Transaction.
Question: But we have a try-catch outside (), why does it happen this exception?
Answer Because of unique Transaction
- When persist() method has an exception
Go to the catch outside
Spring will set the rollBackOnly to true -> it determine we must
rollback the caller (processNextRegistrationMessage) also.
The persist() will rollback itself first.
- Throw an UnexpectedRollbackException to inform that, we need to rollback the caller also.
- The try-catch in run() will catch UnexpectedRollbackException and print the stack trace
Question: Why we change PROPAGATION to REQUIRES_NEW, it works?
Answer: Because now the processNextRegistrationMessage() and persist() are in the different transaction so that they only rollback their transaction.
Thanks
Transaction marked as rollback only: How do I find the cause
I finally understood the problem:
methodA() {
methodB()
}
@Transactional(noRollbackFor = Exception.class)
methodB() {
...
try {
methodC()
} catch (...) {...}
log("OK");
}
@Transactional
methodC() {
throw new ...();
}
What happens is that even though the methodB
has the right annotation, the methodC
does not. When the exception is thrown, the second @Transactional
marks the first transaction as Rollback only anyway.
Why is pydot unable to find GraphViz's executables in Windows 8?
Some things to know about graphviz:
- graphviz is not only a python module, it's also a standalone program. I believe you need both to make graphviz to work.
- The standalone graphviz program was originally developed by AT&T, open sourced, then abandoned. The current maintainers of the package forgot to include Windows registry entries so Python can find the program executable.
- Line 620 of pydotplus\graphviz.py includes a backup path to look for graphviz if it isn't found in the registry. It uses the old ATT file path. Update the file path to what is on your machine (you will need to have administrator privileges) and graphviz should work with pydotplus.
Example:
# Just in case, try the default...
path = r"C:\Program Files (x86)\Graphviz2.38\bin"
The remote server returned an error: (403) Forbidden
Its a permissions error. Your VS probably runs using an elevated account or different user account than the user using the installed version.
It may be useful to check your IIS permissions and see what accounts have access to the resource you are accessing. Cross reference that with the account you use and the account the installed versions are using.
java.rmi.ConnectException: Connection refused to host: 127.0.1.1;
In my case I was unable to edit the hosts file because using a pc from the university.
I fixed the problem running rmiregistry in another port (instead of 1099) with:
rmiregistry <port>
and then running the server on that port.
It was basically an error caused by occupied port.
What causes HttpHostConnectException?
A "connection refused" error happens when you attempt to open a TCP connection to an IP address / port where there is nothing currently listening for connections. If nothing is listening, the OS on the server side "refuses" the connection.
If this is happening intermittently, then the most likely explanations are (IMO):
- the server you are talking ("proxy.xyz.com" / port 60) to is going up and down, OR
- there is something1 between your client and the proxy that is intermittently sending requests to a non-functioning host, or something.
Is this possible that this exception is caused when a search request is made from Android applications as our website don't support a request is being made from android applications.
It seems unlikely. You said that the "connection refused" exception message says that it is the proxy that is refusing the connection, not your server. Besides if a server was going to not handle certain kinds of request, it still has to accept the TCP connection to find out what the request is ... before it can reject it.
1 - For example, it could be a DNS that round-robin resolves the DNS name to different IP addresses. Or it could be an IP-based load balancer.
An Authentication object was not found in the SecurityContext - Spring 3.2.2
For me, the problem was a ContextRefreshedEvent handler. I was doing some data initilization but at that point in the application the Authentication had not been set. It was a catch 22 since the system needed an authentication to authorize and it needed authorization to get the authentication details :). I ended up loosening the authorization from a class level to a method level.
Spring Test & Security: How to mock authentication?
Create a class TestUserDetailsImpl
on your test package:
@Service
@Primary
@Profile("test")
public class TestUserDetailsImpl implements UserDetailsService {
public static final String API_USER = "[email protected]";
private User getAdminUser() {
User user = new User();
user.setUsername(API_USER);
SimpleGrantedAuthority role = new SimpleGrantedAuthority("ROLE_API_USER");
user.setAuthorities(Collections.singletonList(role));
return user;
}
@Override
public UserDetails loadUserByUsername(String username)
throws UsernameNotFoundException {
if (Objects.equals(username, ADMIN_USERNAME))
return getAdminUser();
throw new UsernameNotFoundException(username);
}
}
Rest endpoint:
@GetMapping("/invoice")
@Secured("ROLE_API_USER")
public Page<InvoiceDTO> getInvoices(){
...
}
Test endpoint:
@Test
@WithUserDetails("[email protected]")
public void testApi() throws Exception {
...
}
How to verify a method is called two times with mockito verify()
Using the appropriate VerificationMode:
import static org.mockito.Mockito.atLeast;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
verify(mockObject, atLeast(2)).someMethod("was called at least twice");
verify(mockObject, times(3)).someMethod("was called exactly three times");
Can't access Eclipse marketplace
I know it's a bit old but I ran in the same problem today. I wanted to install eclipse on my vm with xubuntu. Because I've had problems with the latest eclipse version 2019-06 I tried with Oxygen. So I went to eclipse.org and downloaded oxygen. When running oxygen, the problem with merketplace not reachable occurs. So I downloaded the eclipse installer not immediatly the oxygen. After that I can use eclipse as expectet ( all versions)
How to log as much information as possible for a Java Exception?
The java.util.logging
package is standard in Java SE. Its Logger
includes an overloaded log method that accepts Throwable
objects.
It will log stacktraces of exceptions and their cause for you.
For example:
import java.util.logging.Level;
import java.util.logging.Logger;
[...]
Logger logger = Logger.getAnonymousLogger();
Exception e1 = new Exception();
Exception e2 = new Exception(e1);
logger.log(Level.SEVERE, "an exception was thrown", e2);
Will log:
SEVERE: an exception was thrown
java.lang.Exception: java.lang.Exception
at LogStacktrace.main(LogStacktrace.java:21)
Caused by: java.lang.Exception
at LogStacktrace.main(LogStacktrace.java:20)
Internally, this does exactly what @philipp-wendler suggests, by the way.
See the source code for SimpleFormatter.java
. This is just a higher level interface.
Node.js: How to read a stream into a buffer?
You can convert your readable stream to a buffer and integrate it in your code in an asynchronous way like this.
async streamToBuffer (stream) {
return new Promise((resolve, reject) => {
const data = [];
stream.on('data', (chunk) => {
data.push(chunk);
});
stream.on('end', () => {
resolve(Buffer.concat(data))
})
stream.on('error', (err) => {
reject(err)
})
})
}
the usage would be as simple as:
// usage
const myStream // your stream
const buffer = await streamToBuffer(myStream) // this is a buffer
Non-static method requires a target
All the answers are pointing to a Lambda expression with an NRE (Null Reference Exception). I have found that it also occurs when using Linq to Entities. I thought it would be helpful to point out that this exception is not limited to just an NRE inside a Lambda expression.
Jquery and HTML FormData returns "Uncaught TypeError: Illegal invocation"
My experience:
var text = $('#myInputField');
var myObj = {title: 'Some title', content: text};
$.post(myUrl, myObj, callback);
The problem is that I forgot to add .val() to the end of $('#myInputField'); this action makes me waste time trying to figure out what was wrong, causing Illegal Invocation Error, since $('#myInputField') was in a different file than that system pointed out incorrect code. Hope this answer help fellows in the same mistake to avoid to loose time.
SQLException: No suitable Driver Found for jdbc:oracle:thin:@//localhost:1521/orcl
"No suitable driver" usually means that the JDBC
URL you've supplied to connect has incorrect syntax or when the driver isn't loaded at all.
When the method getConnection is called, the DriverManager
will attempt to locate a suitable driver from amongst those loaded at initialization and those loaded explicitly using the same classloader as the current applet or application.(using Class.forName()
)
For Example
import oracle.jdbc.driver.OracleDriver;
Class.forName("oracle.jdbc.driver.OracleDriver");
Also check that you have ojdbc6.jar
in your classpath. I would suggest to place .jar
at physical location to JBoss "$JBOSS_HOME/server/default/lib/"
directory of your project.
EDIT:
You have mentioned hibernate
lately.
Check that your hibernate.cfg.xml
file has connection properties something like this:
<property name="hibernate.connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="hibernate.connection.url">jdbc:oracle:thin:@localhost:1521:orcl</property>
<property name="hibernate.connection.username">scott</property>
<property name="hibernate.connection.password">tiger</property>
Difference between Static methods and Instance methods
In short, static methods and static variables are class level where as instance methods and instance variables are instance or object level.
This means whenever a instance or object (using new ClassName()) is created, this object will retain its own copy of instace variables. If you have five different objects of same class, you will have five different copies of the instance variables. But the static variables and methods will be the same for all those five objects. If you need something common to be used by each object created make it static. If you need a method which won't need object specific data to work, make it static. The static method will only work with static variable or will return data on the basis of passed arguments.
class A {
int a;
int b;
public void setParameters(int a, int b){
this.a = a;
this.b = b;
}
public int add(){
return this.a + this.b;
}
public static returnSum(int s1, int s2){
return (s1 + s2);
}
}
In the above example, when you call add() as:
A objA = new A();
objA.setParameters(1,2); //since it is instance method, call it using object
objA.add(); // returns 3
B objB = new B();
objB.setParameters(3,2);
objB.add(); // returns 5
//calling static method
// since it is a class level method, you can call it using class itself
A.returnSum(4,6); //returns 10
class B{
int s=8;
int t = 8;
public addition(int s,int t){
A.returnSum(s,t);//returns 16
}
}
In first class, add() will return the sum of data passed by a specific object. But the static method can be used to get the sum from any class not independent if any specific instance or object. Hence, for generic methods which only need arguments to work can be made static to keep it all DRY.
deleted object would be re-saved by cascade (remove deleted object from associations)
Kind of Inception going on here.
for (PlaylistadMap playlistadMap : playlistadMaps) {
PlayList innerPlayList = playlistadMap.getPlayList();
for (Iterator<PlaylistadMap> iterator = innerPlayList.getPlaylistadMaps().iterator(); iterator.hasNext();) {
PlaylistadMap innerPlaylistadMap = iterator.next();
if (innerPlaylistadMap.equals(PlaylistadMap)) {
iterator.remove();
session.delete(innerPlaylistadMap);
}
}
}
Passing variables through handlebars partial
This is very possible if you write your own helper. We are using a custom $
helper to accomplish this type of interaction (and more):
/*///////////////////////
Adds support for passing arguments to partials. Arguments are merged with
the context for rendering only (non destructive). Use `:token` syntax to
replace parts of the template path. Tokens are replace in order.
USAGE: {{$ 'path.to.partial' context=newContext foo='bar' }}
USAGE: {{$ 'path.:1.:2' replaceOne replaceTwo foo='bar' }}
///////////////////////////////*/
Handlebars.registerHelper('$', function(partial) {
var values, opts, done, value, context;
if (!partial) {
console.error('No partial name given.');
}
values = Array.prototype.slice.call(arguments, 1);
opts = values.pop();
while (!done) {
value = values.pop();
if (value) {
partial = partial.replace(/:[^\.]+/, value);
}
else {
done = true;
}
}
partial = Handlebars.partials[partial];
if (!partial) {
return '';
}
context = _.extend({}, opts.context||this, _.omit(opts, 'context', 'fn', 'inverse'));
return new Handlebars.SafeString( partial(context) );
});
PowerMockito mock single static method and return object
What you want to do is a combination of part of 1 and all of 2.
You need to use the PowerMockito.mockStatic to enable static mocking for all static methods of a class. This means make it possible to stub them using the when-thenReturn syntax.
But the 2-argument overload of mockStatic you are using supplies a default strategy for what Mockito/PowerMock should do when you call a method you haven't explicitly stubbed on the mock instance.
From the javadoc:
Creates class mock with a specified strategy for its answers to
interactions. It's quite advanced feature and typically you don't need
it to write decent tests. However it can be helpful when working with
legacy systems. It is the default answer so it will be used only when
you don't stub the method call.
The default default stubbing strategy is to just return null, 0 or false for object, number and boolean valued methods. By using the 2-arg overload, you're saying "No, no, no, by default use this Answer subclass' answer method to get a default value. It returns a Long, so if you have static methods which return something incompatible with Long, there is a problem.
Instead, use the 1-arg version of mockStatic to enable stubbing of static methods, then use when-thenReturn to specify what to do for a particular method. For example:
import static org.mockito.Mockito.*;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
class ClassWithStatics {
public static String getString() {
return "String";
}
public static int getInt() {
return 1;
}
}
@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassWithStatics.class)
public class StubJustOneStatic {
@Test
public void test() {
PowerMockito.mockStatic(ClassWithStatics.class);
when(ClassWithStatics.getString()).thenReturn("Hello!");
System.out.println("String: " + ClassWithStatics.getString());
System.out.println("Int: " + ClassWithStatics.getInt());
}
}
The String-valued static method is stubbed to return "Hello!", while the int-valued static method uses the default stubbing, returning 0.
jQuery - Illegal invocation
Just for the record it can also happen if you try to use undeclared variable in data like
var layout = {};
$.ajax({
...
data: {
layout: laoyut // notice misspelled variable name
},
...
});
Save range to variable
To save a range and then call it later, you were just missing the "Set"
Set Remember_Range = Selection or Range("A3")
Remember_Range.Activate
But for copying and pasting, this quicker. Cuts out the middle man and its one line
Sheets("Copy").Range("A3").Value = Sheets("Paste").Range("A3").Value
Verify a method call using Moq
You're checking the wrong method. Moq requires that you Setup (and then optionally Verify) the method in the dependency class.
You should be doing something more like this:
class MyClassTest
{
[TestMethod]
public void MyMethodTest()
{
string action = "test";
Mock<SomeClass> mockSomeClass = new Mock<SomeClass>();
mockSomeClass.Setup(mock => mock.DoSomething());
MyClass myClass = new MyClass(mockSomeClass.Object);
myClass.MyMethod(action);
// Explicitly verify each expectation...
mockSomeClass.Verify(mock => mock.DoSomething(), Times.Once());
// ...or verify everything.
// mockSomeClass.VerifyAll();
}
}
In other words, you are verifying that calling MyClass#MyMethod
, your class will definitely call SomeClass#DoSomething
once in that process. Note that you don't need the Times
argument; I was just demonstrating its value.
Please initialize the log4j system properly warning
None of answered method solve the problem which log4j.properties
file is not found for non-maven jsf web project in NetBeans. So the answer is:
- Create a folder named
resources
in project root folder (outermost folder).
- Right click project in projects explorer in left menu, select properties.
- Open Sources in Categories, add that folder in Source Package Folders.
- Open Run in Categories and add this to VM options:
Dlog4j.configuration=resources/log4j.properties
- Click Ok, build and deploy project as you like, that's it.
I wrote special pattern in log4j file to check whether log4j is used my file:
# Root Logger Option
log4j.rootLogger=INFO, console
# Redirect Log Messages To Console
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.Target=System.out
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%-5p | %d{yyyy-MM-dd HH:mm:ss} | [%t] %C{2} xxxx (%F:%L) - %m%n
I checked it because if you use BasicConfigurator.configure();
in your code in log4j use predefined pattern.
Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)
check if the object exists or not in DB, if it exists get the object and refresh it:
if (getEntityManager().contains(instance)) {
getEntityManager().refresh(instance);
return instance;
}
if it fails the above if condition... find the Object with Id in DB, do the operation which you need, in this case exactly changes will reflects.
if (....) {
} else if (null != identity) {
E dbInstance = (E) getEntityManager().find(instance.getClass(), identity);
return dbInstance;
}
Using Mockito with multiple calls to the same method with the same arguments
Following can be used as a common method to return different arguments on different method calls. Only thing we need to do is we need to pass an array with order in which objects should be retrieved in each call.
@SafeVarargs
public static <Mock> Answer<Mock> getAnswerForSubsequentCalls(final Mock... mockArr) {
return new Answer<Mock>() {
private int count=0, size=mockArr.length;
public Mock answer(InvocationOnMock invocation) throws throwable {
Mock mock = null;
for(; count<size && mock==null; count++){
mock = mockArr[count];
}
return mock;
}
}
}
Ex. getAnswerForSubsequentCalls(mock1, mock3, mock2);
will return mock1 object on first call, mock3 object on second call and mock2 object on third call.
Should be used like when(something()).doAnswer(getAnswerForSubsequentCalls(mock1, mock3, mock2));
This is almost similar to when(something()).thenReturn(mock1, mock3, mock2);
Specify an SSH key for git push for a given domain
One Unix based systems (Linux, BSD, Mac OS X), the default identity is stored in the directory $HOME/.ssh, in 2 files:
private key: $HOME/.ssh/id_rsa
public key: $HOME/.ssh/id_rsa.pub
When you use ssh
without option -i
, it uses the default private key to authenticate with remote system.
If you have another private key you want to use, for example $HOME/.ssh/deploy_key, you have to use ssh -i ~/.ssh/deploy_key ...
It is annoying. You can add the following lines in to your $HOME/.bash_profile :
ssh-add ~/.ssh/deploy_key
ssh-add ~/.ssh/id_rsa
So each time you use ssh
or git
or scp
(basically ssh
too), you don't have to use option -i
anymore.
You can add as many keys as you like in the file $HOME/.bash_profile.
How to send FormData objects with Ajax-requests in jQuery?
You can send the FormData object in ajax request using the following code,
$("form#formElement").submit(function(){
var formData = new FormData($(this)[0]);
});
This is very similar to the accepted answer but an actual answer to the question topic. This will submit the form elements automatically in the FormData and you don't need to manually append the data to FormData variable.
The ajax method looks like this,
$("form#formElement").submit(function(){
var formData = new FormData($(this)[0]);
//append some non-form data also
formData.append('other_data',$("#someInputData").val());
$.ajax({
type: "POST",
url: postDataUrl,
data: formData,
processData: false,
contentType: false,
dataType: "json",
success: function(data, textStatus, jqXHR) {
//process data
},
error: function(data, textStatus, jqXHR) {
//process error msg
},
});
You can also manually pass the form element inside the FormData object as a parameter like this
var formElem = $("#formId");
var formdata = new FormData(formElem[0]);
Hope it helps. ;)
White spaces are required between publicId and systemId
Change the order of statments.
For me, changing the block of code
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/context
http://www.springframework.org/schema/beans/spring-beans.xsd"
with
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context"
is valid.
Can Mockito capture arguments of a method called multiple times?
First of all: you should always import mockito static, this way the code will be much more readable (and intuitive) - the code samples below require it to work:
import static org.mockito.Mockito.*;
In the verify() method you can pass the ArgumentCaptor to assure execution in the test and the ArgumentCaptor to evaluate the arguments:
ArgumentCaptor<MyExampleClass> argument = ArgumentCaptor.forClass(MyExampleClass.class);
verify(yourmock, atleast(2)).myMethod(argument.capture());
List<MyExampleClass> passedArguments = argument.getAllValues();
for (MyExampleClass data : passedArguments){
//assertSometing ...
System.out.println(data.getFoo());
}
The list of all passed arguments during your test is accessible via the argument.getAllValues() method.
The single (last called) argument's value is accessible via the argument.getValue() for further manipulation / checking or whatever you wish to do.
Google Gson - deserialize list<class> object? (generic type)
Method to deserialize generic collection:
import java.lang.reflect.Type;
import com.google.gson.reflect.TypeToken;
...
Type listType = new TypeToken<ArrayList<YourClass>>(){}.getType();
List<YourClass> yourClassList = new Gson().fromJson(jsonArray, listType);
Since several people in the comments have mentioned it, here's an explanation of how the TypeToken
class is being used. The construction new TypeToken<...>() {}.getType()
captures a compile-time type (between the <
and >
) into a runtime java.lang.reflect.Type
object. Unlike a Class
object, which can only represent a raw (erased) type, the Type
object can represent any type in the Java language, including a parameterized instantiation of a generic type.
The TypeToken
class itself does not have a public constructor, because you're not supposed to construct it directly. Instead, you always construct an anonymous subclass (hence the {}
, which is a necessary part of this expression).
Due to type erasure, the TypeToken
class is only able to capture types that are fully known at compile time. (That is, you can't do new TypeToken<List<T>>() {}.getType()
for a type parameter T
.)
For more information, see the documentation for the TypeToken
class.
What's the best way to determine the location of the current PowerShell script?
If you want to load modules from a path relative to where the script runs, such as from a "lib" subfolder", you need to use one of the following:
$PSScriptRoot
which works when invoked as a script, such as via the PowerShell command
$psISE.CurrentFile.FullPath
which works when you're running inside ISE
But if you're in neither, and just typing away within a PowerShell shell, you can use:
pwd.Path
You can could assign one of the three to a variable called $base
depending on the environment you're running under, like so:
$base=$(if ($psISE) {Split-Path -Path $psISE.CurrentFile.FullPath} else {$(if ($global:PSScriptRoot.Length -gt 0) {$global:PSScriptRoot} else {$global:pwd.Path})})
Then in your scripts, you can use it like so:
Import-Module $base\lib\someConstants.psm1
Import-Module $base\lib\myCoolPsModule1.psm1
#etc.
Configure hibernate to connect to database via JNDI Datasource
Tomcat-7 JNDI configuration:
Steps:
- Open the server.xml in the tomcat-dir/conf
- Add below
<Resource>
tag with your DB details inside <GlobalNamingResources>
<Resource name="jdbc/mydb"
global="jdbc/mydb"
auth="Container"
type="javax.sql.DataSource"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/test"
username="root"
password=""
maxActive="10"
maxIdle="10"
minIdle="5"
maxWait="10000"/>
- Save the server.xml file
- Open the context.xml in the tomcat-dir/conf
- Add the below
<ResourceLink>
inside the <Context>
tag.
<ResourceLink name="jdbc/mydb"
global="jdbc/mydb"
auth="Container"
type="javax.sql.DataSource" />
- Save the context.xml
- Open the hibernate-cfg.xml file and add and remove below properties.
Adding:
-------
<property name="connection.datasource">java:comp/env/jdbc/mydb</property>
Removing:
--------
<!--<property name="connection.url">jdbc:mysql://localhost:3306/mydb</property> -->
<!--<property name="connection.username">root</property> -->
<!--<property name="connection.password"></property> -->
- Save the file and put latest .WAR file in tomcat.
- Restart the tomcat. the DB connection will work.
Is this very likely to create a memory leak in Tomcat?
This problem appears when we are using any third party solution, without using the handlers for the cleanup activitiy.
For me this was happening for EhCache. We were using EhCache in our project for caching.
And often we used to see following error in the logs
SEVERE: The web application [/products] appears to have started a thread named [products_default_cache_configuration] but has failed to stop it. This is very likely to create a memory leak.
Aug 07, 2017 11:08:36 AM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/products] appears to have started a thread named [Statistics Thread-products_default_cache_configuration-1] but has failed to stop it. This is very likely to create a memory leak.
And we often noticed tomcat failing for OutOfMemory error during development where we used to do backend changes and deploy the application multiple times for reflecting our changes.
This is the fix we did
<listener>
<listener-class>
net.sf.ehcache.constructs.web.ShutdownListener
</listener-class>
</listener>
So point I am trying to make is check the documentation of the third party libraries which you are using. They should be providing some mechanisms to clean up the threads during shutdown. Which you need to use in your application.
No need to re-invent the wheel unless its not provided by them. The worst case is to provide your own implementation.
Reference for EHCache Shutdown
http://www.ehcache.org/documentation/2.8/operations/shutdown.html
org.xml.sax.SAXParseException: Content is not allowed in prolog
I took code of Dineshkumar and modified to Validate my XML file correctly:
_x000D_
_x000D_
import org.apache.log4j.Logger;_x000D_
_x000D_
public class Myclass{_x000D_
_x000D_
private static final Logger LOGGER = Logger.getLogger(Myclass.class);_x000D_
_x000D_
/**_x000D_
* Validate XML file against Schemas XSD in pathEsquema directory_x000D_
* @param pathEsquema directory that contains XSD Schemas to validate_x000D_
* @param pathFileXML XML file to validate_x000D_
* @throws BusinessException if it throws any Exception_x000D_
*/_x000D_
public static void validarXML(String pathEsquema, String pathFileXML) _x000D_
throws BusinessException{ _x000D_
String W3C_XML_SCHEMA = "http://www.w3.org/2001/XMLSchema";_x000D_
String nameFileXSD = "file.xsd";_x000D_
String MY_SCHEMA1 = pathEsquema+nameFileXSD);_x000D_
ParserErrorHandler parserErrorHandler;_x000D_
try{_x000D_
SchemaFactory schemaFactory = SchemaFactory.newInstance(W3C_XML_SCHEMA);_x000D_
_x000D_
Source [] source = { _x000D_
new StreamSource(new File(MY_SCHEMA1))_x000D_
};_x000D_
Schema schemaGrammar = schemaFactory.newSchema(source);_x000D_
_x000D_
Validator schemaValidator = schemaGrammar.newValidator();_x000D_
schemaValidator.setErrorHandler(_x000D_
parserErrorHandler= new ParserErrorHandler());_x000D_
_x000D_
/** validate xml instance against the grammar. */_x000D_
File file = new File(pathFileXML);_x000D_
InputStream isS= new FileInputStream(file);_x000D_
Reader reader = new InputStreamReader(isS,"UTF-8");_x000D_
schemaValidator.validate(new StreamSource(reader));_x000D_
_x000D_
if(parserErrorHandler.getErrorHandler().isEmpty()&& _x000D_
parserErrorHandler.getFatalErrorHandler().isEmpty()){_x000D_
if(!parserErrorHandler.getWarningHandler().isEmpty()){_x000D_
LOGGER.info(_x000D_
String.format("WARNING validate XML:[%s] Descripcion:[%s]",_x000D_
pathFileXML,parserErrorHandler.getWarningHandler()));_x000D_
}else{_x000D_
LOGGER.info(_x000D_
String.format("OK validate XML:[%s]",_x000D_
pathFileXML));_x000D_
}_x000D_
}else{_x000D_
throw new BusinessException(_x000D_
String.format("Error validate XML:[%s], FatalError:[%s], Error:[%s]",_x000D_
pathFileXML,_x000D_
parserErrorHandler.getFatalErrorHandler(),_x000D_
parserErrorHandler.getErrorHandler()));_x000D_
} _x000D_
}_x000D_
catch(SAXParseException e){_x000D_
throw new BusinessException(String.format("Error validate XML:[%s], SAXParseException:[%s]",_x000D_
pathFileXML,e.getMessage()),e);_x000D_
}_x000D_
catch (SAXException e){_x000D_
throw new BusinessException(String.format("Error validate XML:[%s], SAXException:[%s]",_x000D_
pathFileXML,e.getMessage()),e);_x000D_
}_x000D_
catch (IOException e) {_x000D_
throw new BusinessException(String.format("Error validate XML:[%s], _x000D_
IOException:[%s]",pathFileXML,e.getMessage()),e);_x000D_
}_x000D_
_x000D_
}_x000D_
_x000D_
}
_x000D_
_x000D_
_x000D_
How to pass "Null" (a real surname!) to a SOAP web service in ActionScript 3
It's a kludge, but assuming there's a minimum length for SEARCHSTRING
, for example 2 characters, substring
the SEARCHSTRING
parameter at the second character and pass it as two parameters instead: SEARCHSTRING1 ("Nu")
and SEARCHSTRING2 ("ll").
Concatenate
them back together when executing the query to the database.
com.sun.jdi.InvocationException occurred invoking method
In my case it was due to the object reference getting stale.
I was automating my application using selenium webdriver, so i type something into a text box and then it navigates to another page, so while i come back on the previous page , that object gets stale.
So this was causing the exception, I handled it by again initialising the elements -
PageFactory.initElements(driver, Test.class;
Javascript "Uncaught TypeError: object is not a function" associativity question
I was getting this same error and spent a day and a half trying to find a solution. Naomi's answer lead me to the solution I needed.
My input (type=button) had an attribute name
that was identical to a function name that was being called by the onClick event. Once I changed the attribute name
everything worked.
<input type="button" name="clearEmployer" onClick="clearEmployer();">
changed to:
<input type="button" name="clearEmployerBtn" onClick="clearEmployer();">
How do you do a ‘Pause’ with PowerShell 2.0?
You may want to use FlushInputBuffer
to discard any characters mistakenly typed into the console, especially for long running operations, before using ReadKey
:
Write-Host -NoNewLine 'Press any key to continue...'
$Host.UI.RawUI.FlushInputBuffer()
$Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown') | Out-Null
Doctrine2: Best way to handle many-to-many with extra columns in reference table
I think I would go with @beberlei's suggestion of using proxy methods. What you can do to make this process simpler is to define two interfaces:
interface AlbumInterface {
public function getAlbumTitle();
public function getTracklist();
}
interface TrackInterface {
public function getTrackTitle();
public function getTrackDuration();
}
Then, both your Album
and your Track
can implement them, while the AlbumTrackReference
can still implement both, as following:
class Album implements AlbumInterface {
// implementation
}
class Track implements TrackInterface {
// implementation
}
/** @Entity whatever */
class AlbumTrackReference implements AlbumInterface, TrackInterface
{
public function getTrackTitle()
{
return $this->track->getTrackTitle();
}
public function getTrackDuration()
{
return $this->track->getTrackDuration();
}
public function getAlbumTitle()
{
return $this->album->getAlbumTitle();
}
public function getTrackList()
{
return $this->album->getTrackList();
}
}
This way, by removing your logic that is directly referencing a Track
or an Album
, and just replacing it so that it uses a TrackInterface
or AlbumInterface
, you get to use your AlbumTrackReference
in any possible case. What you will need is to differentiate the methods between the interfaces a bit.
This won't differentiate the DQL nor the Repository logic, but your services will just ignore the fact that you're passing an Album
or an AlbumTrackReference
, or a Track
or an AlbumTrackReference
because you've hidden everything behind an interface :)
Hope this helps!
Hibernate - Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1
I ran into this issue when I was manually beginning and committing transactions inside of method annotated as @Transactional
. I fixed the problem by detecting if an active transaction already existed.
//Detect underlying transaction
if (session.getTransaction() != null && session.getTransaction().isActive()) {
myTransaction = session.getTransaction();
preExistingTransaction = true;
} else {
myTransaction = session.beginTransaction();
}
Then I allowed Spring to handle committing the transaction.
private void finishTransaction() {
if (!preExistingTransaction) {
try {
tx.commit();
} catch (HibernateException he) {
if (tx != null) {
tx.rollback();
}
log.error(he);
} finally {
if (newSessionOpened) {
SessionFactoryUtils.closeSession(session);
newSessionOpened = false;
maxResults = 0;
}
}
}
}
Specify JDK for Maven to use
Maven uses variable $JAVACMD as the final java command, set it to where the java executable is will switch maven to different JDK.
Invoking a jQuery function after .each() has completed
I found a lot of responses dealing with arrays but not with a json object. My solution was simply to iterate through the object once while incrementing a counter and then when iterating through the object to perform your code you can increment a second counter. Then you simply compare the two counters together and get your solution. I know it's a little clunky but I haven't found a more elegant solution so far. This is my example code:
var flag1 = flag2 = 0;
$.each( object, function ( i, v ) { flag1++; });
$.each( object, function ( ky, val ) {
/*
Your code here
*/
flag2++;
});
if(flag1 === flag2) {
your function to call at the end of the iteration
}
Like I said, it's not the most elegant, but it works and it works well and I haven't found a better solution just yet.
Cheers,
JP
Java: Casting Object to Array type
What you've got (according to the debug image) is an object array containing a string array. So you need something like:
Object[] objects = (Object[]) values;
String[] strings = (String[]) objects[0];
You haven't shown the type of values
- if this is already Object[]
then you could just use (String[])values[0]
.
Of course even with the cast to Object[]
you could still do it in one statement, but it's ugly:
String[] strings = (String[]) ((Object[])values)[0];
Is it possible to forward-declare a function in Python?
Yes, we can check this.
Input
print_lyrics()
def print_lyrics():
print("I'm a lumberjack, and I'm okay.")
print("I sleep all night and I work all day.")
def repeat_lyrics():
print_lyrics()
print_lyrics()
repeat_lyrics()
Output
I'm a lumberjack, and I'm okay.
I sleep all night and I work all day.
I'm a lumberjack, and I'm okay.
I sleep all night and I work all day.
I'm a lumberjack, and I'm okay.
I sleep all night and I work all day.
As BJ Homer mentioned over above comments, A general rule in Python is not that function should be defined higher in the code (as in Pascal), but that it should be defined before its usage.
Hope that helps.
Function passed as template argument
Template parameters can be either parameterized by type (typename T) or by value (int X).
The "traditional" C++ way of templating a piece of code is to use a functor - that is, the code is in an object, and the object thus gives the code unique type.
When working with traditional functions, this technique doesn't work well, because a change in type doesn't indicate a specific function - rather it specifies only the signature of many possible functions. So:
template<typename OP>
int do_op(int a, int b, OP op)
{
return op(a,b);
}
int add(int a, int b) { return a + b; }
...
int c = do_op(4,5,add);
Isn't equivalent to the functor case. In this example, do_op is instantiated for all function pointers whose signature is int X (int, int). The compiler would have to be pretty aggressive to fully inline this case. (I wouldn't rule it out though, as compiler optimization has gotten pretty advanced.)
One way to tell that this code doesn't quite do what we want is:
int (* func_ptr)(int, int) = add;
int c = do_op(4,5,func_ptr);
is still legal, and clearly this is not getting inlined. To get full inlining, we need to template by value, so the function is fully available in the template.
typedef int(*binary_int_op)(int, int); // signature for all valid template params
template<binary_int_op op>
int do_op(int a, int b)
{
return op(a,b);
}
int add(int a, int b) { return a + b; }
...
int c = do_op<add>(4,5);
In this case, each instantiated version of do_op is instantiated with a specific function already available. Thus we expect the code for do_op to look a lot like "return a + b". (Lisp programmers, stop your smirking!)
We can also confirm that this is closer to what we want because this:
int (* func_ptr)(int,int) = add;
int c = do_op<func_ptr>(4,5);
will fail to compile. GCC says: "error: 'func_ptr' cannot appear in a constant-expression. In other words, I can't fully expand do_op because you haven't given me enough info at compiler time to know what our op is.
So if the second example is really fully inlining our op, and the first is not, what good is the template? What is it doing? The answer is: type coercion. This riff on the first example will work:
template<typename OP>
int do_op(int a, int b, OP op) { return op(a,b); }
float fadd(float a, float b) { return a+b; }
...
int c = do_op(4,5,fadd);
That example will work! (I am not suggesting it is good C++ but...) What has happened is do_op has been templated around the signatures of the various functions, and each separate instantiation will write different type coercion code. So the instantiated code for do_op with fadd looks something like:
convert a and b from int to float.
call the function ptr op with float a and float b.
convert the result back to int and return it.
By comparison, our by-value case requires an exact match on the function arguments.
"Least Astonishment" and the Mutable Default Argument
When we do this:
def foo(a=[]):
...
... we assign the argument a
to an unnamed list, if the caller does not pass the value of a.
To make things simpler for this discussion, let's temporarily give the unnamed list a name. How about pavlo
?
def foo(a=pavlo):
...
At any time, if the caller doesn't tell us what a
is, we reuse pavlo
.
If pavlo
is mutable (modifiable), and foo
ends up modifying it, an effect we notice the next time foo
is called without specifying a
.
So this is what you see (Remember, pavlo
is initialized to []):
>>> foo()
[5]
Now, pavlo
is [5].
Calling foo()
again modifies pavlo
again:
>>> foo()
[5, 5]
Specifying a
when calling foo()
ensures pavlo
is not touched.
>>> ivan = [1, 2, 3, 4]
>>> foo(a=ivan)
[1, 2, 3, 4, 5]
>>> ivan
[1, 2, 3, 4, 5]
So, pavlo
is still [5, 5]
.
>>> foo()
[5, 5, 5]
Spring - @Transactional - What happens in background?
When Spring loads your bean definitions, and has been configured to look for @Transactional
annotations, it will create these proxy objects around your actual bean. These proxy objects are instances of classes that are auto-generated at runtime. The default behaviour of these proxy objects when a method is invoked is just to invoke the same method on the "target" bean (i.e. your bean).
However, the proxies can also be supplied with interceptors, and when present these interceptors will be invoked by the proxy before it invokes your target bean's method. For target beans annotated with @Transactional
, Spring will create a TransactionInterceptor
, and pass it to the generated proxy object. So when you call the method from client code, you're calling the method on the proxy object, which first invokes the TransactionInterceptor
(which begins a transaction), which in turn invokes the method on your target bean. When the invocation finishes, the TransactionInterceptor
commits/rolls back the transaction. It's transparent to the client code.
As for the "external method" thing, if your bean invokes one of its own methods, then it will not be doing so via the proxy. Remember, Spring wraps your bean in the proxy, your bean has no knowledge of it. Only calls from "outside" your bean go through the proxy.
Does that help?
What is a method group in C#?
The ToString
function has many overloads - the method group would be the group consisting of all the different overloads for that function.
c++ integer->std::string conversion. Simple function?
Like mentioned earlier, I'd recommend boost lexical_cast. Not only does it have a fairly nice syntax:
#include <boost/lexical_cast.hpp>
std::string s = boost::lexical_cast<std::string>(i);
it also provides some safety:
try{
std::string s = boost::lexical_cast<std::string>(i);
}catch(boost::bad_lexical_cast &){
...
}
JOptionPane Input to int
String String_firstNumber = JOptionPane.showInputDialog("Input Semisecond");
int Int_firstNumber = Integer.parseInt(firstNumber);
Now your Int_firstnumber
contains integer value of String_fristNumber
.
hope it helped
How do I mock a service that returns promise in AngularJS Jasmine unit test?
You can use a stubbing library like sinon to mock your service. You can then return $q.when() as your promise. If your scope object's value comes from the promise result, you will need to call scope.$root.$digest().
var scope, controller, datacontextMock, customer;
beforeEach(function () {
module('app');
inject(function ($rootScope, $controller,common, datacontext) {
scope = $rootScope.$new();
var $q = common.$q;
datacontextMock = sinon.stub(datacontext);
customer = {id:1};
datacontextMock.customer.returns($q.when(customer));
controller = $controller('Index', { $scope: scope });
})
});
it('customer id to be 1.', function () {
scope.$root.$digest();
expect(controller.customer.id).toBe(1);
});
How to undo a SQL Server UPDATE query?
If you already have a full backup from your database, fortunately, you have an option in SQL Management Studio. In this case, you can use the following steps:
Right click on database -> Tasks -> Restore -> Database.
In General tab, click on Timeline -> select Specific date and time option.
Move the timeline slider to before update command time -> click OK.
In the destination database name, type a new name.
In the Files tab, check in Reallocate all files to folder and then select a new path to save your recovered database.
In the options tab, check in Overwrite ... and remove Take tail-log... check option.
Finally, click on OK and wait until the recovery process is over.
I have used this method myself in an operational database and it was very useful.
What is "Linting"?
Linting is the process of checking the source code for Programmatic as well as Stylistic errors. This is most helpful in identifying some common and uncommon mistakes that are made during coding.
A Lint
or a Linter
is a program that supports linting (verifying code quality). They are available for most languages like JavaScript, CSS, HTML, Python, etc..
Some of the useful linters are JSLint, CSSLint, JSHint, Pylint
How do I uninstall a Windows service if the files do not exist anymore?
1st Step : Move to the Directory where your service is present
Command : cd c:\xxx\yyy\service
2nd Step : Enter the below command
Command : C:\Windows\Microsoft.NET\Framework\v4.0.30319\InstallUtil.exe service.exe \u
Here service.exe is your service exe and \u will uninstall the service.
you'll see "The uninstall has completed" message.
If you wanna install a service, Remove \u in the above command which will install your service
Why doesn't Java offer operator overloading?
Sometimes it would be nice to have operator overloading, friend classes and multiple inheritance.
However I still think it was a good decision. If Java would have had operator overloading then we could never be sure of operator meanings without looking through source code. At present that's not necessary. And I think your example of using methods instead of operator overloading is also quite readable. If you want to make things more clear you could always add a comment above hairy statements.
// a = b + c
Complex a, b, c; a = b.add(c);
Using different Web.config in development and production environment
This is one of the huge benefits of using the machine.config. At my last job, we had development, test and production environments. We could use the machine.config for things like connection strings (to the appropriate, dev/test/prod SQL machine).
This may not be a solution for you if you don't have access to the actual production machine (like, if you were using a hosting company on a shared host).
How do I check whether an array contains a string in TypeScript?
TS has many utility methods for arrays which are available via the prototype of Arrays. There are multiple which can achieve this goal but the two most convenient for this purpose are:
Array.indexOf()
Takes any value as an argument and then returns the first index at which a given element can be found in the array, or -1 if it is not present.
Array.includes()
Takes any value as an argument and then determines whether an array includes a this value. The method returning true
if the value is found, otherwise false
.
Example:
const channelArray: string[] = ['one', 'two', 'three'];
console.log(channelArray.indexOf('three')); // 2
console.log(channelArray.indexOf('three') > -1); // true
console.log(channelArray.indexOf('four') > -1); // false
console.log(channelArray.includes('three')); // true
How to upgrade safely php version in wamp server
WAMP server generally provide addond for different php/mysql versions. However you mentioned you have downloaded latest wamp server. As of now, latest Wamp server v2.5 provide PHP version 5.5.12
So you need to upgrade it manually as follow:
- Download binaries on php.net
- Extract all files in a new folder : C:/wamp/bin/php/php5.5.27/
- Copy the wampserver.conf from another php folder (like php/php5.5.12/) to the new folder
- Rename php.ini-development file to phpForApache.ini
- Done ! Restart WampServer (>Right Mouseclick on trayicon >Exit)
Although not asked, I'd recommend to vagrant/puppet or docker for local development. Check puphpet.com for details. It has slight learning curve but it will give you much better control of different versions of every tool.
possibly undefined macro: AC_MSG_ERROR
I had the same problem with the Macports port "openocd" (locally modified the Portfile to use the git repository) on a freshly installed machine.
The permanent fix is easy, define a dependency to pkgconfig in the Portfile:
depends_lib-append port:pkgconfig
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare();
I got this exception because I was trying to make a Toast popup from a background thread.
Toast needs an Activity to push to the user interface and threads don't have that.
So one workaround is to give the thread a link to the parent Activity and Toast to that.
Put this code in the thread where you want to send a Toast message:
parent.runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(parent.getBaseContext(), "Hello", Toast.LENGTH_LONG).show();
}
});
Keep a link to the parent Activity in the background thread that created this thread. Use parent variable in your thread class:
private static YourActivity parent;
When you create the thread, pass the parent Activity as a parameter through the constructor like this:
public YourBackgroundThread(YourActivity parent) {
this.parent = parent;
}
Now the background thread can push Toast messages to the screen.
Function or sub to add new row and data to table
Minor variation on Geoff's answer.
New Data in Array:
Sub AddDataRow(tableName As String, NewData As Variant)
Dim sheet As Worksheet
Dim table As ListObject
Dim col As Integer
Dim lastRow As Range
Set sheet = Range(tableName).Parent
Set table = sheet.ListObjects.Item(tableName)
'First check if the last row is empty; if not, add a row
If table.ListRows.Count > 0 Then
Set lastRow = table.ListRows(table.ListRows.Count).Range
If Application.CountBlank(lastRow) < lastRow.Columns.Count Then
table.ListRows.Add
End If
End If
'Iterate through the last row and populate it with the entries from values()
Set lastRow = table.ListRows(table.ListRows.Count).Range
For col = 1 To lastRow.Columns.Count
If col <= UBound(NewData) + 1 Then lastRow.Cells(1, col) = NewData(col - 1)
Next col
End Sub
New Data in Horizontal Range:
Sub AddDataRow(tableName As String, NewData As Range)
Dim sheet As Worksheet
Dim table As ListObject
Dim col As Integer
Dim lastRow As Range
Set sheet = Range(tableName).Parent
Set table = sheet.ListObjects.Item(tableName)
'First check if the last table row is empty; if not, add a row
If table.ListRows.Count > 0 Then
Set lastRow = table.ListRows(table.ListRows.Count).Range
If Application.CountBlank(lastRow) < lastRow.Columns.Count Then
table.ListRows.Add
End If
End If
'Copy NewData to new table record
Set lastRow = table.ListRows(table.ListRows.Count).Range
lastRow.Value = NewData.Value
End Sub
Efficient way to Handle ResultSet in Java
A couple of things to enhance the other answers. First, you should never return a HashMap
, which is a specific implementation. Return instead a plain old java.util.Map
. But that's actually not right for this example, anyway. Your code only returns the last row of the ResultSet as a (Hash)Map. You instead want to return a List<Map<String,Object>>
. Think about how you should modify your code to do that. (Or you could take Dave Newton's suggestion).
ViewBag, ViewData and TempData
TempData
Basically it's like a DataReader, once read, data will be lost.
Example
public class HomeController : Controller
{
public ActionResult Index()
{
ViewBag.Message = "Welcome to ASP.NET MVC!";
TempData["T"] = "T";
return RedirectToAction("About");
}
public ActionResult About()
{
return RedirectToAction("Test1");
}
public ActionResult Test1()
{
String str = TempData["T"]; //Output - T
return View();
}
}
If you pay attention to the above code, RedirectToAction has no impact over the TempData until TempData is read. So, once TempData is read, values will be lost.
How can i keep the TempData after reading?
Check the output in Action Method Test 1 and Test 2
public class HomeController : Controller
{
public ActionResult Index()
{
ViewBag.Message = "Welcome to ASP.NET MVC!";
TempData["T"] = "T";
return RedirectToAction("About");
}
public ActionResult About()
{
return RedirectToAction("Test1");
}
public ActionResult Test1()
{
string Str = Convert.ToString(TempData["T"]);
TempData.Keep(); // Keep TempData
return RedirectToAction("Test2");
}
public ActionResult Test2()
{
string Str = Convert.ToString(TempData["T"]); //OutPut - T
return View();
}
}
If you pay attention to the above code, data is not lost after RedirectToAction as well as after Reading the Data and the reason is, We are using TempData.Keep()
. is that
In this way you can make it persist as long as you wish in other controllers also.
ViewBag/ViewData
The Data will persist to the corresponding View
How to return the output of stored procedure into a variable in sql server
With the Return statement from the proc, I needed to assign the temp variable and pass it to another stored procedure. The value was getting assigned fine but when passing it as a parameter, it lost the value. I had to create a temp table and set the variable from the table (SQL 2008)
From this:
declare @anID int
exec @anID = dbo.StoredProc_Fetch @ID, @anotherID, @finalID
exec dbo.ADifferentStoredProc @anID (no value here)
To this:
declare @t table(id int)
declare @anID int
insert into @t exec dbo.StoredProc_Fetch @ID, @anotherID, @finalID
set @anID= (select Top 1 * from @t)
Get safe area inset top and bottom heights
None of the other answers here worked for me, but this did.
var topSafeAreaHeight: CGFloat = 0
var bottomSafeAreaHeight: CGFloat = 0
if #available(iOS 11.0, *) {
let window = UIApplication.shared.windows[0]
let safeFrame = window.safeAreaLayoutGuide.layoutFrame
topSafeAreaHeight = safeFrame.minY
bottomSafeAreaHeight = window.frame.maxY - safeFrame.maxY
}
Clicking a checkbox with ng-click does not update the model
How about changing
<input type='checkbox' ng-click='onCompleteTodo(todo)' ng-model="todo.done">
to
<input type='checkbox' ng-change='onCompleteTodo(todo)' ng-model="todo.done">
From docs:
Evaluate given expression when user changes the input. The expression is not evaluated when the value change is coming from the model.
Note, this directive requires ngModel
to be present.
How do Python's any and all functions work?
The concept is simple:
M =[(1, 1), (5, 6), (0, 0)]
1) print([any(x) for x in M])
[True, True, False] #only the last tuple does not have any true element
2) print([all(x) for x in M])
[True, True, False] #all elements of the last tuple are not true
3) print([not all(x) for x in M])
[False, False, True] #NOT operator applied to 2)
4) print([any(x) and not all(x) for x in M])
[False, False, False] #AND operator applied to 1) and 3)
# if we had M =[(1, 1), (5, 6), (1, 0)], we could get [False, False, True] in 4)
# because the last tuple satisfies both conditions: any of its elements is TRUE
#and not all elements are TRUE
Can't install any package with node npm
Following on from LAXIT KUMAR's recommendation, we've found that at times the registry URL can get corrupted, not sure how this is happening, however to cure, just reset it:
npm config set registry https://registry.npmjs.org
The 404 disappeared as it was going to the correct location again.
Make div fill remaining space along the main axis in flexbox
Use the flex-grow
property to make a flex item consume free space on the main axis.
This property will expand the item as much as possible, adjusting the length to dynamic environments, such as screen re-sizing or the addition / removal of other items.
A common example is flex-grow: 1
or, using the shorthand property, flex: 1
.
Hence, instead of width: 96%
on your div, use flex: 1
.
You wrote:
So at the moment, it's set to 96% which looks OK until you really squash the screen - then the right hand div gets a bit starved of the space it needs.
The squashing of the fixed-width div is related to another flex property: flex-shrink
By default, flex items are set to flex-shrink: 1
which enables them to shrink in order to prevent overflow of the container.
To disable this feature use flex-shrink: 0
.
For more details see The flex-shrink
factor section in the answer here:
Learn more about flex alignment along the main axis here:
Learn more about flex alignment along the cross axis here:
Change the column label? e.g.: change column "A" to column "Name"
If you intend to change A, B, C.... you see high above the columns, you can not. You can hide A, B, C...:
Button Office(top left)
Excel Options(bottom)
Advanced(left)
Right looking: Display options fot this worksheet:
Select the worksheet(eg. Sheet3)
Uncheck: Show column and row headers
Ok
Using Python's os.path, how do I go up one directory?
I think the easiest thing to do is just to reuse dirname()
So you can call
os.path.dirname(os.path.dirname( __file__ ))
if you file is at /Users/hobbes3/Sites/mysite/templates/method.py
This will return "/Users/hobbes3/Sites/mysite"
Viewing PDF in Windows forms using C#
you can use System.Diagnostics.Process.Start as well as WIN32 ShellExecute function by means of interop, for opening PDF files using the default viewer:
System.Diagnostics.Process.Start("SOMEAPP.EXE","Path/SomeFile.Ext");
[System.Runtime.InteropServices.DllImport("shell32. dll")]
private static extern long ShellExecute(Int32 hWnd, string lpOperation,
string lpFile, string lpParameters,
string lpDirectory, long nShowCmd);
Another approach is to place a WebBrowser Control into your Form and then use the Navigate method for opening the PDF file:
ThewebBrowserControl.Navigate(@"c:\the_file.pdf");
Text overflow ellipsis on two lines
It seems more elegant combining two classes. You can drop two-lines
class if only one row need see:
_x000D_
_x000D_
.ellipse {_x000D_
white-space: nowrap;_x000D_
display:inline-block;_x000D_
overflow: hidden;_x000D_
text-overflow: ellipsis;_x000D_
}_x000D_
.two-lines {_x000D_
-webkit-line-clamp: 2;_x000D_
display: -webkit-box;_x000D_
-webkit-box-orient: vertical;_x000D_
white-space: normal;_x000D_
}_x000D_
.width{_x000D_
width:100px;_x000D_
border:1px solid hotpink;_x000D_
}
_x000D_
<span class='width ellipse'>_x000D_
some texts some texts some texts some texts some texts some texts some texts_x000D_
</span>_x000D_
_x000D_
<span class='width ellipse two-lines'>_x000D_
some texts some texts some texts some texts some texts some texts some texts_x000D_
</span>
_x000D_
_x000D_
_x000D_
List all sequences in a Postgres db 8.1 with SQL
Note, that starting from PostgreSQL 8.4 you can get all information about sequences used in the database via:
SELECT * FROM information_schema.sequences;
Since I'm using a higher version of PostgreSQL (9.1), and was searching for same answer high and low, I added this answer for posterity's sake and for future searchers.
"Too many values to unpack" Exception
That exception means that you are trying to unpack a tuple, but the tuple has too many values with respect to the number of target variables. For example: this work, and prints 1, then 2, then 3
def returnATupleWithThreeValues():
return (1,2,3)
a,b,c = returnATupleWithThreeValues()
print a
print b
print c
But this raises your error
def returnATupleWithThreeValues():
return (1,2,3)
a,b = returnATupleWithThreeValues()
print a
print b
raises
Traceback (most recent call last):
File "c.py", line 3, in ?
a,b = returnATupleWithThreeValues()
ValueError: too many values to unpack
Now, the reason why this happens in your case, I don't know, but maybe this answer will point you in the right direction.
How to redirect the output of print to a TXT file
Building on previous answers, I think it's a perfect use case for doing it (simple) context manager style:
import sys
class StdoutRedirection:
"""Standard output redirection context manager"""
def __init__(self, path):
self._path = path
def __enter__(self):
sys.stdout = open(self._path, mode="w")
return self
def __exit__(self, exc_type, exc_val, exc_tb):
sys.stdout.close()
sys.stdout = sys.__stdout__
and then:
with StdoutRedirection("path/to/file"):
print("Hello world")
Also it would be really easy to add some functionality to StdoutRedirection
class (e.g. a method that lets you change the path)
Java default constructor
Hi. As per my knowledge let me clear the concept of default constructor:
The compiler automatically provides a no-argument, default constructor
for any class without constructors. This default constructor will call
the no-argument constructor of the superclass. In this situation, the
compiler will complain if the superclass doesn't have a no-argument
constructor so you must verify that it does. If your class has no
explicit superclass, then it has an implicit superclass of Object,
which does have a no-argument constructor.
I read this information from the Java Tutorials.
What does ECU units, CPU core and memory mean when I launch a instance
ECUs (EC2 Computer Units) are a rough measure of processor performance that was introduced by Amazon to let you compare their EC2 instances ("servers").
CPU performance is of course a multi-dimensional measure, so putting a single number on it (like "5 ECU") can only be a rough approximation. If you want to know more exactly how well a processor performs for a task you have in mind, you should choose a benchmark that is similar to your task.
In early 2014, there was a nice benchmarking site comparing cloud hosting offers by tens of different benchmarks, over at CloudHarmony benchmarks. However, this seems gone now (and archive.org can't help as it was a web application). Only an introductory blog post is still available.
Also useful: ec2instances.info, which at least aggregates the ECU information of different EC2 instances for comparison. (Add column "Compute Units (ECU)" to make it work.)
How to enter a formula into a cell using VBA?
You aren't building your formula right.
Worksheets("EmployeeCosts").Range("B" & var1a).Formula = "=SUM(H5:H" & var1a & ")"
This does the same as the following lines do:
Dim myFormula As String
myFormula = "=SUM(H5:H"
myFormula = myFormula & var1a
myformula = myformula & ")"
which is what you are trying to do.
Also, you want to have the =
at the beginning of the formala.
Getting "net::ERR_BLOCKED_BY_CLIENT" error on some AJAX calls
As it has been explained here, beside of multiple extensions that perform ad or script blocking you may aware that this may happen by file names as below:
Particularly in the AdBlock Plus the character string "-300x600" is causing the Failed to Load Resource
ERR_BLOCKED_BY_CLIENT problem.
As shown in the picture, some of the images were blocked because of the '-300x600' pattern in their name, that particular text pattern matches an expression list pattern in the AdBlock Plus.
Generate a random point within a circle (uniformly)
Such a fun problem.
The rationale of the probability of a point being chosen lowering as distance from the axis origin increases is explained multiple times above. We account for that by taking the root of U[0,1].
Here's a general solution for a positive r in Python 3.
import numpy
import math
import matplotlib.pyplot as plt
def sq_point_in_circle(r):
"""
Generate a random point in an r radius circle
centered around the start of the axis
"""
t = 2*math.pi*numpy.random.uniform()
R = (numpy.random.uniform(0,1) ** 0.5) * r
return(R*math.cos(t), R*math.sin(t))
R = 200 # Radius
N = 1000 # Samples
points = numpy.array([sq_point_in_circle(R) for i in range(N)])
plt.scatter(points[:, 0], points[:,1])
You don't have permission to access / on this server
Check the apache User and Group setting in the httpd.conf. It should default to apache on AMI/RedHat or www-data on Debian.
grep '^Group\|^User' /etc/httpd/conf/httpd.conf
Then add the apache user to the group setting of your site's root directory.
sudo usermod -a -G <your-site-root-dir-group> apache
How to convert list data into json in java
public static List<Product> getCartList() {
JSONObject responseDetailsJson = new JSONObject();
JSONArray jsonArray = new JSONArray();
List<Product> cartList = new Vector<Product>(cartMap.keySet().size());
for(Product p : cartMap.keySet()) {
cartList.add(p);
JSONObject formDetailsJson = new JSONObject();
formDetailsJson.put("id", "1");
formDetailsJson.put("name", "name1");
jsonArray.add(formDetailsJson);
}
responseDetailsJson.put("forms", jsonArray);//Here you can see the data in json format
return cartList;
}
you can get the data in the following form
{
"forms": [
{ "id": "1", "name": "name1" },
{ "id": "2", "name": "name2" }
]
}
WebDriver: check if an element exists?
As the comment stated, this is in C# not Java but the idea is the same. I've researched this issue extensively and ultimately the issue is, FindElement always returns an exception when the element doesn't exist. There isn't an overloaded option that allows you to get null or anything else. Here is why I prefer this solution over others.
- Returning a list of elements then checking if the list size is 0 works but you lose functionality that way. You can't do a .click() on a collection of links even if the collection size is 1.
- You could assert that the element exists but often that stops your testing. In some cases, I have an extra link to click depending on how I got to that page and I want to click it if it exists or move on otherwise.
- It's only slow if you don't set the timeout driver.Manage().Timeouts().ImplicitlyWait(TimeSpan.FromSeconds(0));
It's actually a very simple and elegant once the method is created. By using FindElementSafe instead of FindElement, I don't "see" the ugly try/catch block and I can use a simple Exists method. That would look something like this:
IWebElement myLink = driver.FindElementSafe(By.Id("myId"));
if (myLink.Exists)
{
myLink.Click();
}
Here is how you extend IWebElement & IWebDriver
IWebDriver.FindElementSafe
/// <summary>
/// Same as FindElement only returns null when not found instead of an exception.
/// </summary>
/// <param name="driver">current browser instance</param>
/// <param name="by">The search string for finding element</param>
/// <returns>Returns element or null if not found</returns>
public static IWebElement FindElementSafe(this IWebDriver driver, By by)
{
try
{
return driver.FindElement(by);
}
catch (NoSuchElementException)
{
return null;
}
}
IWebElement.Exists
/// <summary>
/// Requires finding element by FindElementSafe(By).
/// Returns T/F depending on if element is defined or null.
/// </summary>
/// <param name="element">Current element</param>
/// <returns>Returns T/F depending on if element is defined or null.</returns>
public static bool Exists(this IWebElement element)
{
if (element == null)
{ return false; }
return true;
}
You could use polymorphism to modify the IWebDriver class instance of FindElement but that's a bad idea from a maintenance standpoint.
Resource files not found from JUnit test cases
This is actually redundant except in cases where you want to override the defaults. All of these settings are implied defaults.
You can verify that by checking your effective POM using this command
mvn help:effective-pom
<finalName>name</finalName>
<directory>target</directory>
<outputDirectory>target/classes</outputDirectory>
<testOutputDirectory>target/test-classes</testOutputDirectory>
<sourceDirectory>src/main/java</sourceDirectory>
<testSourceDirectory>src/test/java</testSourceDirectory>
<resources>
<resource>
<directory>src/main/resources</directory>
</resource>
</resources>
<testResources>
<testResource>
<directory>src/test/resources</directory>
</testResource>
</testResources>
For example, if i want to point to a different test resource path or resource path you should use this otherwise you don't.
<resources>
<resource>
<directory>/home/josh/desktop/app_resources</directory>
</resource>
</resources>
<testResources>
<testResource>
<directory>/home/josh/desktop/test_resources</directory>
</testResource>
</testResources>
Using R to list all files with a specified extension
files <- list.files(pattern = "\\.dbf$")
$
at the end means that this is end of string. "dbf$"
will work too, but adding \\.
(.
is special character in regular expressions so you need to escape it) ensure that you match only files with extension .dbf
(in case you have e.g. .adbf
files).
If a DOM Element is removed, are its listeners also removed from memory?
Don't hesitate to watch heap to see memory leaks in event handlers keeping a reference to the element with a closure and the element keeping a reference to the event handler.
Garbage collector do not like circular references.
Usual memory leak case:
admit an object has a ref to an element. That element has a ref to the handler. And the handler has a ref to the object.
The object has refs to a lot of other objects. This object was part of a collection you think you have thrown away by unreferencing it from your collection.
=> the whole object and all it refers will remain in memory till page exit.
=> you have to think about a complete killing method for your object class or trust a mvc framework for example.
Moreover, don't hesitate to use the Retaining tree part of Chrome dev tools.
Uncaught ReferenceError: angular is not defined - AngularJS not working
As you know angular.module
( declared under angular.js file.So before accessing angular.module, you must have make it available by using <script src="lib/angular/angular.js"></script>
(In your case) after then you can call angular.module
. It will work.
like
<html lang="en">
<head>
<meta charset="utf-8">
<title>My AngularJS App</title>
<link rel="stylesheet" href="css/app.css"/>
<!-- In production use:
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.min.js"></script>
-->
<script src="lib/angular/angular.js"></script>
<script src="lib/angular/angular-route.js"></script>
<script src="js/app.js"></script>
<script src="js/services.js"></script>
<script src="js/controllers.js"></script>
<script src="js/filters.js"></script>
<script src="js/directives.js"></script>
<script>
var app = angular.module('myApp',[]);
app.directive('myDirective',function(){
return function(scope, element,attrs) {
element.bind('click',function() {alert('click')});
};
});
</script>
</head>
<body ng-app="myApp">
<div >
<button my-directive>Click Me!</button>
</div>
<h1>{{2+3}}</h1>
</body>
</html>
How to run a script file remotely using SSH
Backticks will run the command on the local shell and put the results on the command line. What you're saying is 'execute ./test/foo.sh and then pass the output as if I'd typed it on the commandline here'.
Try the following command, and make sure that thats the path from your home directory on the remote computer to your script.
ssh kev@server1 './test/foo.sh'
Also, the script has to be on the remote computer. What this does is essentially log you into the remote computer with the listed command as your shell. You can't run a local script on a remote computer like this (unless theres some fun trick I don't know).
How to align title at center of ActionBar in default theme(Theme.Holo.Light)
It seems there is no way to do this without custom view. You can get the title view:
View decor = getWindow().getDecorView();
TextView title = (TextView) decor.findViewById(getResources().getIdentifier("action_bar_title", "id", "android"));
But changing of gravity
or layout_gravity
doesn't have an effect.
The problem in the ActionBarView
, which layout its children by itself so changing of layout params of its children also doesn't have an effect.
To see this excecute following code:
ViewGroup actionBar = (ViewGroup) decor.findViewById(getResources().getIdentifier("action_bar", "id", "android"));
View v = actionBar.getChildAt(0);
ActionBar.LayoutParams p = new ActionBar.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
p.gravity= Gravity.CENTER;
v.setLayoutParams(p);
v.setBackgroundColor(Color.BLACK);
H2 in-memory database. Table not found
Had the exact same issue, tried all the above, but without success.
The rather funny cause of the error was that the JVM started too fast, before the DB table was created (using a data.sql file in src.main.resources). So I've put a Thread.sleep(1000) timer to wait for just a second before calling "select * from person".
Working flawlessly now.
application.properties:
spring.h2.console.enabled=true
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=
data.sql:
create table person
(
id integer not null,
name varchar(255) not null,
location varchar(255),
birth_date timestamp,
primary key(id)
);
insert into person values (
10001, 'Tofu', 'home', sysdate()
);
PersonJdbcDAO.java:
public List<Person> findAllPersons(){
return jdbcTemplate.query("select * from person",
new BeanPropertyRowMapper<Person>(Person.class));
}
main class:
Thread.sleep(1000);
logger.info("All users -> {}", dao.findAllPersons());
Different ways of loading a file as an InputStream
Plain old Java on plain old Java 7 and no other dependencies demonstrates the difference...
I put file.txt
in c:\temp\
and I put c:\temp\
on the classpath.
There is only one case where there is a difference between the two call.
class J {
public static void main(String[] a) {
// as "absolute"
// ok
System.err.println(J.class.getResourceAsStream("/file.txt") != null);
// pop
System.err.println(J.class.getClassLoader().getResourceAsStream("/file.txt") != null);
// as relative
// ok
System.err.println(J.class.getResourceAsStream("./file.txt") != null);
// ok
System.err.println(J.class.getClassLoader().getResourceAsStream("./file.txt") != null);
// no path
// ok
System.err.println(J.class.getResourceAsStream("file.txt") != null);
// ok
System.err.println(J.class.getClassLoader().getResourceAsStream("file.txt") != null);
}
}
Html Agility Pack get all elements by class
You can solve your issue by using the 'contains' function within your Xpath query, as below:
var allElementsWithClassFloat =
_doc.DocumentNode.SelectNodes("//*[contains(@class,'float')]")
To reuse this in a function do something similar to the following:
string classToFind = "float";
var allElementsWithClassFloat =
_doc.DocumentNode.SelectNodes(string.Format("//*[contains(@class,'{0}')]", classToFind));
Where to put the gradle.properties file
Actually there are 3 places where gradle.properties
can be placed:
- Under gradle user home directory defined by the
GRADLE_USER_HOME
environment variable, which if not set defaults to USER_HOME/.gradle
- The sub-project directory (
myProject2
in your case)
- The root project directory (under
myProject
)
Gradle looks for gradle.properties
in all these places while giving precedence to properties definition based on the order above. So for example, for a property defined in gradle user home directory (#1) and the sub-project (#2) its value will be taken from gradle user home directory (#1).
You can find more details about it in gradle documentation here.
'Static readonly' vs. 'const'
Another difference between declaring const and static readonly is in memory allocation.
A static field belongs to the type of an object rather than to an instance of that type. As a result, once the class is referenced for the first time, the static field would "live" in the memory for the rest of time, and the same instance of the static field would be referenced by all instances of the type.
On the other hand, a const field "belongs to an instance of the type.
If memory of deallocation is more important for you, prefer to use const. If speed, then use static readonly.
Unit tests vs Functional tests
According to ISTQB those two are not comparable. Functional testing is not integration testing.
Unit test is one of tests level and functional testing is type of testing.
Basically:
The function of a system (or component) is 'what it does'. This is
typically described in a requirements specification, a functional
specification, or in use cases.
while
Component testing, also known as unit, module and program testing,
searches for defects in, and verifies the functioning of software
(e.g. modules, programs, objects, classes, etc.) that are separately
testable.
According to ISTQB component/unit test can be functional or not-functional:
Component testing may include testing of functionality and specific non-functional characteristics such as resource-behavior (e.g. memory leaks), performance or robustness testing, as well as structural testing (e.g. decision coverage).
Quotes from Foundations of software testing - ISTQB certification
How do you UrlEncode without using System.Web?
In .Net 4.5+ use WebUtility
Just for formatting I'm submitting this as an answer.
Couldn't find any good examples comparing them so:
string testString = "http://test# space 123/text?var=val&another=two";
Console.WriteLine("UrlEncode: " + System.Web.HttpUtility.UrlEncode(testString));
Console.WriteLine("EscapeUriString: " + Uri.EscapeUriString(testString));
Console.WriteLine("EscapeDataString: " + Uri.EscapeDataString(testString));
Console.WriteLine("EscapeDataReplace: " + Uri.EscapeDataString(testString).Replace("%20", "+"));
Console.WriteLine("HtmlEncode: " + System.Web.HttpUtility.HtmlEncode(testString));
Console.WriteLine("UrlPathEncode: " + System.Web.HttpUtility.UrlPathEncode(testString));
//.Net 4.0+
Console.WriteLine("WebUtility.HtmlEncode: " + WebUtility.HtmlEncode(testString));
//.Net 4.5+
Console.WriteLine("WebUtility.UrlEncode: " + WebUtility.UrlEncode(testString));
Outputs:
UrlEncode: http%3a%2f%2ftest%23+space+123%2ftext%3fvar%3dval%26another%3dtwo
EscapeUriString: http://test#%20space%20123/text?var=val&another=two
EscapeDataString: http%3A%2F%2Ftest%23%20space%20123%2Ftext%3Fvar%3Dval%26another%3Dtwo
EscapeDataReplace: http%3A%2F%2Ftest%23+space+123%2Ftext%3Fvar%3Dval%26another%3Dtwo
HtmlEncode: http://test# space 123/text?var=val&another=two
UrlPathEncode: http://test#%20space%20123/text?var=val&another=two
//.Net 4.0+
WebUtility.HtmlEncode: http://test# space 123/text?var=val&another=two
//.Net 4.5+
WebUtility.UrlEncode: http%3A%2F%2Ftest%23+space+123%2Ftext%3Fvar%3Dval%26another%3Dtwo
In .Net 4.5+ use WebUtility
.UrlEncode
This appears to replicate HttpUtility.UrlEncode
(pre-v4.0) for the more common characters:
Uri.EscapeDataString(testString).Replace("%20", "+").Replace("'", "%27").Replace("~", "%7E")
Note: EscapeUriString
will keep a valid uri string, which causes it to use as many plaintext characters as possible.
See this answer for a Table Comparing the various Encodings:
https://stackoverflow.com/a/11236038/555798
Line Breaks
All of them listed here (other than HttpUtility.HtmlEncode
) will convert "\n\r"
into %0a%0d
or %0A%0D
Please feel free to edit this and add new characters to my test string, or leave them in the comments and I'll edit it.
Change Bootstrap tooltip color
for Bootstrap 4 version via CSS:
if you want to change the background color of balloon:
/* change style balloon */
.tooltip-inner {
background-color: green !important;
color: #fff;
}
if you want to change the arrow when appear in bottom position:
/* change style arrow */
.bs-tooltip-auto[x-placement^=bottom] .arrow::before, .bs-tooltip-bottom .arrow::before {
border-bottom-color: #f00;
}
Hope help you
How to overlay images
If you're only wanting the magnifing glass on hover then you can use
a:hover img { cursor: url(glass.cur); }
http://www.javascriptkit.com/dhtmltutors/csscursors.shtml
If you want it there permanently you should probably either have it included in the original thumnail, or add it using JavaScript rather than adding it to the HTML (this is purely style and shouldn't be in the content).
Let me know if you want help on the JavaScript side.
convert UIImage to NSData
Create the reference of image....
UIImage *rainyImage = [UIImage imageNamed:@"rainy.jpg"];
displaying image in image view... imagedisplay is reference of imageview:
imagedisplay.image = rainyImage;
convert it into NSData
by passing UIImage
reference and provide compression quality in float values:
NSData *imgData = UIImageJPEGRepresentation(rainyImage, 0.9);
Use JavaScript to place cursor at end of text in text input element
I faced this same issue (after setting focus through RJS/prototype) in IE.
Firefox was already leaving the cursor at the end when there is already a value for the field. IE was forcing the cursor to the beginning of the text.
The solution I arrived at is as follows:
<input id="search" type="text" value="mycurrtext" size="30"
onfocus="this.value = this.value;" name="search"/>
This works in both IE7 and FF3
How can I print the contents of an array horizontally?
public static void Main(string[] args)
{
int[] numbers = new int[10];
Console.Write("index ");
for (int i = 0; i < numbers.Length; i++)
{
numbers[i] = i;
Console.Write(numbers[i] + " ");
}
Console.WriteLine("");
Console.WriteLine("");
Console.Write("value ");
for (int i = 0; i < numbers.Length; i++)
{
numbers[i] = numbers.Length - i;
Console.Write(numbers[i] + " ");
}
Console.ReadKey();
}
Python Socket Receive Large Amount of Data
I think this question has been pretty well answered, but I just wanted to add a method using Python 3.8 and the new assignment expression (walrus operator) since it is stylistically simple.
import socket
host = "127.0.0.1"
port = 31337
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host,port))
s.listen()
con, addr = s.accept()
msg_list = []
while (walrus_msg := con.recv(3)) != b'\r\n':
msg_list.append(walrus_msg)
print(msg_list)
In this case, 3 bytes are received from the socket and immediately assigned to walrus_msg
. Once the socket receives a b'\r\n'
it breaks the loop. walrus_msg
are added to a msg_list
and printed after the loop breaks. This script is basic but was tested and works with a telnet session.
NOTE: The parenthesis around the (walrus_msg := con.recv(3))
are needed. Without this, while walrus_msg := con.recv(3) != b'\r\n':
evaluates walrus_msg
to True
instead of the actual data on the socket.
Recover from git reset --hard?
I accidentally ran git reset --hard
on my repo today too while having uncommitted changes too today. To get it back, I ran git fsck --lost-found
, which wrote all unreferenced blobs to <path to repo>/.git/lost-found/
. Since the files were uncommitted, I found them in the other
directory within the <path to repo>/.git/lost-found/
. From there, I can see the uncommitted files using git show <filename>
, copy out the blobs, and rename them.
Note: This only works if you added the files you want to save to the index (using git add .
). If the files weren't in the index, they are lost.
How to fix 'android.os.NetworkOnMainThreadException'?
Just to spell out something explicitly:
The main thread is basically the UI thread.
So saying that you cannot do networking operations in the main thread means you cannot do networking operations in the UI thread, which means you cannot do networking operations in a *runOnUiThread(new Runnable() { ... }*
block inside some other thread, either.
(I just had a long head-scratching moment trying to figure out why I was getting that error somewhere other than my main thread. This was why; this thread helped; and hopefully this comment will help someone else.)
Map with Key as String and Value as List in Groovy
One additional small piece that is helpful when dealing with maps/list as the value in a map is the withDefault(Closure)
method on maps in groovy. Instead of doing the following code:
Map m = [:]
for(object in listOfObjects)
{
if(m.containsKey(object.myKey))
{
m.get(object.myKey).add(object.myValue)
}
else
{
m.put(object.myKey, [object.myValue]
}
}
You can do the following:
Map m = [:].withDefault{key -> return []}
for(object in listOfObjects)
{
List valueList = m.get(object.myKey)
m.put(object.myKey, valueList)
}
With default can be used for other things as well, but I find this the most common use case for me.
API:
http://www.groovy-lang.org/gdk.html
Map -> withDefault(Closure)
What does $1 mean in Perl?
These are called "match variables". As previously mentioned they contain the text from your last regular expression match.
More information is in Essential Perl. (Ctrl + F for 'Match Variables' to find the corresponding section.)
How can I print the contents of a hash in Perl?
If you want to be pedantic and keep it to one line (without use statements and shebang), then I'll sort of piggy back off of tetromino's answer and suggest:
print Dumper( { 'abc' => 123, 'def' => [4,5,6] } );
Not doing anything special other than using the anonymous hash to skip the temp variable ;)
PHP ini file_get_contents external url
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://www.your_external_website.com");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
$result = curl_exec($ch);
curl_close($ch);
is best for http url,
But how to open https url help me
How can I get the request URL from a Java Filter?
Building on another answer on this page,
public static String getCurrentUrlFromRequest(ServletRequest request)
{
if (! (request instanceof HttpServletRequest))
return null;
return getCurrentUrlFromRequest((HttpServletRequest)request);
}
public static String getCurrentUrlFromRequest(HttpServletRequest request)
{
StringBuffer requestURL = request.getRequestURL();
String queryString = request.getQueryString();
if (queryString == null)
return requestURL.toString();
return requestURL.append('?').append(queryString).toString();
}
Sequelize, convert entity to plain object
I have found a solution that works fine for nested model and array using native JavaScript functions.
var results = [{},{},...]; //your result data returned from sequelize query
var jsonString = JSON.stringify(results); //convert to string to remove the sequelize specific meta data
var obj = JSON.parse(jsonString); //to make plain json
// do whatever you want to do with obj as plain json
How to set environment variables in Jenkins?
EnvInject Plugin aka (Environment Injector Plugin) gives you several options to set environment variables from Jenkins configuration.
By selecting Inject environment variables to the build process
you will get:
Evaluated Groovy script
gives you possibility to set environment variable based on result of executed command:
return [HOSTNAME_SHELL: 'hostname'.execute().text,
DATE_SHELL: 'date'.execute().text,
ECHO_SHELL: 'echo hello world!'.execute().text
]
- or with explicit
Groovy
code:
return [HOSTNAME_GROOVY: java.net.InetAddress.getLocalHost().getHostName(),
DATE_GROOVY: new Date()
]
(More details about each method could be found in build-in help (?))
Unfortunately you can't do the same from Script Content
as it states:
Execute a script file aimed at setting an environment such as creating
folders, copying files, and so on. Give the script file content. You
can use the above properties variables. However, adding or overriding
environment variables in the script doesn't have any impacts in the
build job.
Twitter Bootstrap tabs not working: when I click on them nothing happens
i had the same problem until i downloaded bootstrap-tab.js and included it in my script, download from here https://code.google.com/p/fusionleaf/source/browse/webroot/fusionleaf/com/www/inc/bootstrap/js/bootstrap-tab.js?r=82aacd63ee1f7f9a15ead3574fe2c3f45b5c1027
include the bootsrap-tab.js in the just below the jquery
<script type="text/javascript" src="bootstrap/js/bootstrap-tab.js"></script>
Final Code Looked like this:
<!DOCTYPE html>
<html lang="en">
<head>
<link href="bootstrap/css/bootstrap.css" rel="stylesheet">
<script type="text/javascript" src="libraries/jquery.js"></script>
<script type="text/javascript" src="bootstrap/js/bootstrap.js"></script>
<script type="text/javascript" src="bootstrap/js/bootstrap-tab.js"></script>
</head>
<body>
<div class="container">
<!-------->
<div id="content">
<ul id="tabs" class="nav nav-tabs" data-tabs="tabs">
<li class="active"><a href="#red" data-toggle="tab">Red</a></li>
<li><a href="#orange" data-toggle="tab">Orange</a></li>
<li><a href="#yellow" data-toggle="tab">Yellow</a></li>
<li><a href="#green" data-toggle="tab">Green</a></li>
<li><a href="#blue" data-toggle="tab">Blue</a></li>
</ul>
<div id="my-tab-content" class="tab-content">
<div class="tab-pane active" id="red">
<h1>Red</h1>
<p>red red red red red red</p>
</div>
<div class="tab-pane" id="orange">
<h1>Orange</h1>
<p>orange orange orange orange orange</p>
</div>
<div class="tab-pane" id="yellow">
<h1>Yellow</h1>
<p>yellow yellow yellow yellow yellow</p>
</div>
<div class="tab-pane" id="green">
<h1>Green</h1>
<p>green green green green green</p>
</div>
<div class="tab-pane" id="blue">
<h1>Blue</h1>
<p>blue blue blue blue blue</p>
</div>
</div>
</div>
<script type="text/javascript">
jQuery(document).ready(function ($) {
$('#tabs').tab();
});
</script>
</div> <!-- container -->
<script type="text/javascript" src="bootstrap/js/bootstrap.js"></script>
</body>
</html>
What is path of JDK on Mac ?
The location has changed from Java 6 (provided by Apple) to Java 7 and onwards (provided by Oracle). The best generic way to find this out is to run
/usr/libexec/java_home
This is the natively supported way to find out both the path to the default Java installation as well as all alternative ones present.
If you check out its help text (java_home -h
), you'll see that you can use this command to reliably start a Java program on OS X (java_home --exec ...
), with the ability to explicitly specify the desired Java version and architecture, or even request the user to install it if missing.
A more pedestrian approach, but one which will help you trace specifically which Java installation the command java
resolves into, goes like this:
run
which java
if that gives you something like /usr/bin/java
, which is a symbolic link to the real location, run
ls -l `which java`
On my system, this outputs
/usr/bin/java -> /Library/Java/JavaVirtualMachines/jdk1.7.0_25.jdk/Contents/Home/bin/java
and therefrom you can read the Java home directory;
if usr/bin/java
points to another symbolic link, recursively apply the same approach with
ls -l <whatever the /usr/bin/java symlink points to>
An important variation is the setup you get if you start by installing Apple's Java and later install Oracle's. In that case Step 2 above will give you
/usr/bin/java -> /System/Library/Frameworks/JavaVM.framework/Commands/java
and that particular java
binary is a stub which will resolve the actual java
command to call by consulting the JAVA_HOME
environment variable and, if it's not set or doesn't point to a Java home directory, will fall back to calling java_home
. It is important to have this in mind when debugging your setup.
JavaScript, get date of the next day
You can use:
var tomorrow = new Date();
tomorrow.setDate(new Date().getDate()+1);
For example, since there are 30 days in April, the following code will output May 1:
var day = new Date('Apr 30, 2000');
console.log(day); // Apr 30 2000
var nextDay = new Date(day);
nextDay.setDate(day.getDate() + 1);
console.log(nextDay); // May 01 2000
See fiddle.
Check file uploaded is in csv format
Mime type option is not best option for validating CSV file. I used this code this worked well in all browser
$type = explode(".",$_FILES['file']['name']);
if(strtolower(end($type)) == 'csv'){
}
else
{
}
pandas loc vs. iloc vs. at vs. iat?
There are two primary ways that pandas makes selections from a DataFrame.
- By Label
- By Integer Location
The documentation uses the term position for referring to integer location. I do not like this terminology as I feel it is confusing. Integer location is more descriptive and is exactly what .iloc
stands for. The key word here is INTEGER - you must use integers when selecting by integer location.
Before showing the summary let's all make sure that ...
.ix is deprecated and ambiguous and should never be used
There are three primary indexers for pandas. We have the indexing operator itself (the brackets []
), .loc
, and .iloc
. Let's summarize them:
[]
- Primarily selects subsets of columns, but can select rows as well. Cannot simultaneously select rows and columns.
.loc
- selects subsets of rows and columns by label only
.iloc
- selects subsets of rows and columns by integer location only
I almost never use .at
or .iat
as they add no additional functionality and with just a small performance increase. I would discourage their use unless you have a very time-sensitive application. Regardless, we have their summary:
.at
selects a single scalar value in the DataFrame by label only
.iat
selects a single scalar value in the DataFrame by integer location only
In addition to selection by label and integer location, boolean selection also known as boolean indexing exists.
Examples explaining .loc
, .iloc
, boolean selection and .at
and .iat
are shown below
We will first focus on the differences between .loc
and .iloc
. Before we talk about the differences, it is important to understand that DataFrames have labels that help identify each column and each row. Let's take a look at a sample DataFrame:
df = pd.DataFrame({'age':[30, 2, 12, 4, 32, 33, 69],
'color':['blue', 'green', 'red', 'white', 'gray', 'black', 'red'],
'food':['Steak', 'Lamb', 'Mango', 'Apple', 'Cheese', 'Melon', 'Beans'],
'height':[165, 70, 120, 80, 180, 172, 150],
'score':[4.6, 8.3, 9.0, 3.3, 1.8, 9.5, 2.2],
'state':['NY', 'TX', 'FL', 'AL', 'AK', 'TX', 'TX']
},
index=['Jane', 'Nick', 'Aaron', 'Penelope', 'Dean', 'Christina', 'Cornelia'])
All the words in bold are the labels. The labels, age
, color
, food
, height
, score
and state
are used for the columns. The other labels, Jane
, Nick
, Aaron
, Penelope
, Dean
, Christina
, Cornelia
are used as labels for the rows. Collectively, these row labels are known as the index.
The primary ways to select particular rows in a DataFrame are with the .loc
and .iloc
indexers. Each of these indexers can also be used to simultaneously select columns but it is easier to just focus on rows for now. Also, each of the indexers use a set of brackets that immediately follow their name to make their selections.
.loc selects data only by labels
We will first talk about the .loc
indexer which only selects data by the index or column labels. In our sample DataFrame, we have provided meaningful names as values for the index. Many DataFrames will not have any meaningful names and will instead, default to just the integers from 0 to n-1, where n is the length(number of rows) of the DataFrame.
There are many different inputs you can use for .loc
three out of them are
- A string
- A list of strings
- Slice notation using strings as the start and stop values
Selecting a single row with .loc with a string
To select a single row of data, place the index label inside of the brackets following .loc
.
df.loc['Penelope']
This returns the row of data as a Series
age 4
color white
food Apple
height 80
score 3.3
state AL
Name: Penelope, dtype: object
Selecting multiple rows with .loc with a list of strings
df.loc[['Cornelia', 'Jane', 'Dean']]
This returns a DataFrame with the rows in the order specified in the list:
Selecting multiple rows with .loc with slice notation
Slice notation is defined by a start, stop and step values. When slicing by label, pandas includes the stop value in the return. The following slices from Aaron to Dean, inclusive. Its step size is not explicitly defined but defaulted to 1.
df.loc['Aaron':'Dean']
Complex slices can be taken in the same manner as Python lists.
.iloc selects data only by integer location
Let's now turn to .iloc
. Every row and column of data in a DataFrame has an integer location that defines it. This is in addition to the label that is visually displayed in the output. The integer location is simply the number of rows/columns from the top/left beginning at 0.
There are many different inputs you can use for .iloc
three out of them are
- An integer
- A list of integers
- Slice notation using integers as the start and stop values
Selecting a single row with .iloc with an integer
df.iloc[4]
This returns the 5th row (integer location 4) as a Series
age 32
color gray
food Cheese
height 180
score 1.8
state AK
Name: Dean, dtype: object
Selecting multiple rows with .iloc with a list of integers
df.iloc[[2, -2]]
This returns a DataFrame of the third and second to last rows:
Selecting multiple rows with .iloc with slice notation
df.iloc[:5:3]
Simultaneous selection of rows and columns with .loc and .iloc
One excellent ability of both .loc/.iloc
is their ability to select both rows and columns simultaneously. In the examples above, all the columns were returned from each selection. We can choose columns with the same types of inputs as we do for rows. We simply need to separate the row and column selection with a comma.
For example, we can select rows Jane, and Dean with just the columns height, score and state like this:
df.loc[['Jane', 'Dean'], 'height':]
This uses a list of labels for the rows and slice notation for the columns
We can naturally do similar operations with .iloc
using only integers.
df.iloc[[1,4], 2]
Nick Lamb
Dean Cheese
Name: food, dtype: object
Simultaneous selection with labels and integer location
.ix
was used to make selections simultaneously with labels and integer location which was useful but confusing and ambiguous at times and thankfully it has been deprecated. In the event that you need to make a selection with a mix of labels and integer locations, you will have to make both your selections labels or integer locations.
For instance, if we want to select rows Nick
and Cornelia
along with columns 2 and 4, we could use .loc
by converting the integers to labels with the following:
col_names = df.columns[[2, 4]]
df.loc[['Nick', 'Cornelia'], col_names]
Or alternatively, convert the index labels to integers with the get_loc
index method.
labels = ['Nick', 'Cornelia']
index_ints = [df.index.get_loc(label) for label in labels]
df.iloc[index_ints, [2, 4]]
Boolean Selection
The .loc indexer can also do boolean selection. For instance, if we are interested in finding all the rows where age is above 30 and return just the food
and score
columns we can do the following:
df.loc[df['age'] > 30, ['food', 'score']]
You can replicate this with .iloc
but you cannot pass it a boolean series. You must convert the boolean Series into a numpy array like this:
df.iloc[(df['age'] > 30).values, [2, 4]]
Selecting all rows
It is possible to use .loc/.iloc
for just column selection. You can select all the rows by using a colon like this:
df.loc[:, 'color':'score':2]
The indexing operator, []
, can slice can select rows and columns too but not simultaneously.
Most people are familiar with the primary purpose of the DataFrame indexing operator, which is to select columns. A string selects a single column as a Series and a list of strings selects multiple columns as a DataFrame.
df['food']
Jane Steak
Nick Lamb
Aaron Mango
Penelope Apple
Dean Cheese
Christina Melon
Cornelia Beans
Name: food, dtype: object
Using a list selects multiple columns
df[['food', 'score']]
What people are less familiar with, is that, when slice notation is used, then selection happens by row labels or by integer location. This is very confusing and something that I almost never use but it does work.
df['Penelope':'Christina'] # slice rows by label
df[2:6:2] # slice rows by integer location
The explicitness of .loc/.iloc
for selecting rows is highly preferred. The indexing operator alone is unable to select rows and columns simultaneously.
df[3:5, 'color']
TypeError: unhashable type: 'slice'
Selection by .at
and .iat
Selection with .at
is nearly identical to .loc
but it only selects a single 'cell' in your DataFrame. We usually refer to this cell as a scalar value. To use .at
, pass it both a row and column label separated by a comma.
df.at['Christina', 'color']
'black'
Selection with .iat
is nearly identical to .iloc
but it only selects a single scalar value. You must pass it an integer for both the row and column locations
df.iat[2, 5]
'FL'
ValueError: setting an array element with a sequence
for those who are having trouble with similar problems in Numpy, a very simple solution would be:
defining dtype=object
when defining an array for assigning values to it. for instance:
out = np.empty_like(lil_img, dtype=object)
How to retrieve a recursive directory and file list from PowerShell excluding some files and folders?
The Get-ChildItem cmdlet has an -Exclude
parameter that is tempting to use but it doesn't work for filtering out entire directories from what I can tell. Try something like this:
function GetFiles($path = $pwd, [string[]]$exclude)
{
foreach ($item in Get-ChildItem $path)
{
if ($exclude | Where {$item -like $_}) { continue }
if (Test-Path $item.FullName -PathType Container)
{
$item
GetFiles $item.FullName $exclude
}
else
{
$item
}
}
}
Using android.support.v7.widget.CardView in my project (Eclipse)
I have done following and it resolve an issue with recyclerview same you may use for other widget as well if it's not working in eclipse project.
• Go to sdk\extras\android\m2repository\com\android\support\recyclerview-v7\21.0.0-rc1 directory
• Copy recyclerview-v7-21.0.0-rc1.aar file and rename it as .zip
• Unzip the file, you will get classes.jar (rename the jar file more meaningful name)
• Use the following jar in your project build path or lib directory.
and it resolve your error.
happy coding :)
YYYY-MM-DD format date in shell script
You can set date as environment variable and later u can use it
setenv DATE `date "+%Y-%m-%d"`
echo "----------- ${DATE} -------------"
or
DATE =`date "+%Y-%m-%d"`
echo "----------- ${DATE} -------------"
AngularJS routing without the hash '#'
Using HTML5 mode requires URL rewriting on server side, basically you have to rewrite all your links to entry point of your application (e.g. index.html). Requiring a <base>
tag is also important for this case, as it allows AngularJS to differentiate between the part of the url that is the application base and the path that should be handled by the application. For more information, see AngularJS Developer Guide - Using $location HTML5 mode Server Side.
Update
How to: Configure your server to work with html5Mode1
When you have html5Mode enabled, the #
character will no longer be used in your urls. The #
symbol is useful because it requires no server side configuration. Without #
, the url looks much nicer, but it also requires server side rewrites. Here are some examples:
Apache Rewrites
<VirtualHost *:80>
ServerName my-app
DocumentRoot /path/to/app
<Directory /path/to/app>
RewriteEngine on
# Don't rewrite files or directories
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
# Rewrite everything else to index.html to allow html5 state links
RewriteRule ^ index.html [L]
</Directory>
</VirtualHost>
Nginx Rewrites
server {
server_name my-app;
index index.html;
root /path/to/app;
location / {
try_files $uri $uri/ /index.html;
}
}
Azure IIS Rewrites
<system.webServer>
<rewrite>
<rules>
<rule name="Main Rule" stopProcessing="true">
<match url=".*" />
<conditions logicalGrouping="MatchAll">
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
</conditions>
<action type="Rewrite" url="/" />
</rule>
</rules>
</rewrite>
</system.webServer>
Express Rewrites
var express = require('express');
var app = express();
app.use('/js', express.static(__dirname + '/js'));
app.use('/dist', express.static(__dirname + '/../dist'));
app.use('/css', express.static(__dirname + '/css'));
app.use('/partials', express.static(__dirname + '/partials'));
app.all('/*', function(req, res, next) {
// Just send the index.html for other files to support HTML5Mode
res.sendFile('index.html', { root: __dirname });
});
app.listen(3006); //the port you want to use
See also
jQuery scrollTop not working in Chrome but working in Firefox
If it work all fine for Mozilla, with html,body selector, then there is a good chance that the problem is related to the overflow, if the overflow in html or body is set to auto, then this will cause chrome to not work well, cause when it is set to auto, scrollTop property on animate will not work, i don't know exactly why! but the solution is to omit the overflow, don't set it! that solved it for me! if you are setting it to auto, take it off!
if you are setting it to hidden, then do as it is described in "user2971963" answer (ctrl+f to find it). hope this is useful!
Are SSL certificates bound to the servers ip address?
The SSL certificates are going to be bound to hostname rather than IP if they are setup in the standard way. Hence why it works at one site rather than the other.
Even if the servers share the same hostname they may well have two different certificates and hence WebSphere will have a certificate trust issue as it won't be able to recognise the certificate on the second server as it is different to the first.
How to inspect FormData?
Already answered but if you want to retrieve values in an easy way from a submitted form you can use the spread operator combined with creating a new Map iterable to get a nice structure.
new Map([...new FormData(form)])
PHPExcel Make first row bold
$objPHPExcel->getActiveSheet()->getStyle('1:1')->getFont()->setBold(true);
That way you get the complete first row
How to activate JMX on my JVM for access with jconsole?
The relevant documentation can be found here:
http://java.sun.com/javase/6/docs/technotes/guides/management/agent.html
Start your program with following parameters:
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=9010
-Dcom.sun.management.jmxremote.rmi.port=9010
-Dcom.sun.management.jmxremote.local.only=false
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false
For instance like this:
java -Dcom.sun.management.jmxremote \
-Dcom.sun.management.jmxremote.port=9010 \
-Dcom.sun.management.jmxremote.local.only=false \
-Dcom.sun.management.jmxremote.authenticate=false \
-Dcom.sun.management.jmxremote.ssl=false \
-jar Notepad.jar
-Dcom.sun.management.jmxremote.local.only=false
is not necessarily required
but without it, it doesn't work on Ubuntu. The error would be something like
this:
01 Oct 2008 2:16:22 PM sun.rmi.transport. customer .TCPTransport$AcceptLoop executeAcceptLoop
WARNING: RMI TCP Accept-0: accept loop for ServerSocket[addr=0.0.0.0/0.0.0.0,port=0,localport=37278] throws
java.io.IOException: The server sockets created using the LocalRMIServerSocketFactory only accept connections from clients running on the host where the RMI remote objects have been exported.
at sun.management.jmxremote.LocalRMIServerSocketFactory$1.accept(LocalRMIServerSocketFactory.java:89)
at sun.rmi.transport. customer .TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:387)
at sun.rmi.transport. customer .TCPTransport$AcceptLoop.run(TCPTransport.java:359)
at java.lang.Thread.run(Thread.java:636)
see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6754672
Also be careful with -Dcom.sun.management.jmxremote.authenticate=false
which
makes access available for anyone, but if you only use it to track the JVM on
your local machine it doesn't matter.
Update:
In some cases I was not able to reach the server. This was then fixed if I set this parameter as well: -Djava.rmi.server.hostname=127.0.0.1
Flutter: Run method on Widget build complete
If you are looking for ReactNative's componentDidMount
equivalent, Flutter has it. It's not that simple but it's working just the same way. In Flutter, Widget
s do not handle their events directly. Instead they use their State
object to do that.
class MyWidget extends StatefulWidget{
@override
State<StatefulWidget> createState() => MyState(this);
Widget build(BuildContext context){...} //build layout here
void onLoad(BuildContext context){...} //callback when layout build done
}
class MyState extends State<MyWidget>{
MyWidget widget;
MyState(this.widget);
@override
Widget build(BuildContext context) => widget.build(context);
@override
void initState() => widget.onLoad(context);
}
State.initState
immediately will be called once upon screen has finishes rendering the layout. And will never again be called even on hot reload if you're in debug mode, until explicitly reaches time to do so.
Sanitizing strings to make them URL and filename safe?
Some observations on your solution:
- 'u' at the end of your pattern means that the pattern, and not the text it's matching will be interpreted as UTF-8 (I presume you assumed the latter?).
- \w matches the underscore character. You specifically include it for files which leads to the assumption that you don't want them in URLs, but in the code you have URLs will be permitted to include an underscore.
- The inclusion of "foreign UTF-8" seems to be locale-dependent. It's not clear whether this is the locale of the server or client. From the PHP docs:
A "word" character is any letter or digit or the underscore character, that is, any character which can be part of a Perl "word". The definition of letters and digits is controlled by PCRE's character tables, and may vary if locale-specific matching is taking place. For example, in the "fr" (French) locale, some character codes greater than 128 are used for accented letters, and these are matched by \w.
Creating the slug
You probably shouldn't include accented etc. characters in your post slug since, technically, they should be percent encoded (per URL encoding rules) so you'll have ugly looking URLs.
So, if I were you, after lowercasing, I'd convert any 'special' characters to their equivalent (e.g. é -> e) and replace non [a-z] characters with '-', limiting to runs of a single '-' as you've done. There's an implementation of converting special characters here: https://web.archive.org/web/20130208144021/http://neo22s.com/slug
Sanitization in general
OWASP have a PHP implementation of their Enterprise Security API which among other things includes methods for safe encoding and decoding input and output in your application.
The Encoder interface provides:
canonicalize (string $input, [bool $strict = true])
decodeFromBase64 (string $input)
decodeFromURL (string $input)
encodeForBase64 (string $input, [bool $wrap = false])
encodeForCSS (string $input)
encodeForHTML (string $input)
encodeForHTMLAttribute (string $input)
encodeForJavaScript (string $input)
encodeForOS (Codec $codec, string $input)
encodeForSQL (Codec $codec, string $input)
encodeForURL (string $input)
encodeForVBScript (string $input)
encodeForXML (string $input)
encodeForXMLAttribute (string $input)
encodeForXPath (string $input)
https://github.com/OWASP/PHP-ESAPI
https://www.owasp.org/index.php/Category:OWASP_Enterprise_Security_API
How do I round to the nearest 0.5?
There are several options. If performance is a concern, test them to see which works fastest in a large loop.
double Adjust(double input)
{
double whole = Math.Truncate(input);
double remainder = input - whole;
if (remainder < 0.3)
{
remainder = 0;
}
else if (remainder < 0.8)
{
remainder = 0.5;
}
else
{
remainder = 1;
}
return whole + remainder;
}
How to make inline plots in Jupyter Notebook larger?
If you only want the image of your figure to appear larger without changing the general appearance of your figure increase the figure resolution. Changing the figure size as suggested in most other answers will change the appearance since font sizes do not scale accordingly.
import matplotlib.pylab as plt
plt.rcParams['figure.dpi'] = 200
How to force delete a file?
You have to close that application first. There is no way to delete it, if it's used by some application.
UnLock IT is a neat utility that helps you to take control of any file or folder when it is locked by some application or system. For every locked resource, you get a list of locking processes and can unlock it by terminating those processes. EMCO Unlock IT offers Windows Explorer integration that allows unlocking files and folders by one click in the context menu.
There's also Unlocker (not recommended, see Warning below), which is a free tool which helps locate any file locking handles running, and give you the option to turn it off. Then you can go ahead and do anything you want with those files.
Warning: The installer includes a lot of undesirable stuff. You're almost certainly better off with UnLock IT.
C# Test if user has write access to a folder
I agree with Ash, that should be fine. Alternatively you could use declarative CAS and actually prevent the program from running in the first place if they don't have access.
I believe some of the CAS features may not be present in C# 4.0 from what I've heard, not sure if that might be an issue or not.
Dump a list in a pickle file and retrieve it back later
Pickling will serialize your list (convert it, and it's entries to a unique byte string), so you can save it to disk. You can also use pickle to retrieve your original list, loading from the saved file.
So, first build a list, then use pickle.dump
to send it to a file...
Python 3.4.1 (default, May 21 2014, 12:39:51)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = ['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>>
>>> import pickle
>>>
>>> with open('parrot.pkl', 'wb') as f:
... pickle.dump(mylist, f)
...
>>>
Then quit and come back later… and open with pickle.load
...
Python 3.4.1 (default, May 21 2014, 12:39:51)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pickle
>>> with open('parrot.pkl', 'rb') as f:
... mynewlist = pickle.load(f)
...
>>> mynewlist
['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>>
Asserting successive calls to a mock method
assert_has_calls
is another approach to this problem.
From the docs:
assert_has_calls (calls, any_order=False)
assert the mock has been
called with the specified calls. The mock_calls list is checked for
the calls.
If any_order is False (the default) then the calls must be sequential.
There can be extra calls before or after the specified calls.
If any_order is True then the calls can be in any order, but they must
all appear in mock_calls.
Example:
>>> from unittest.mock import call, Mock
>>> mock = Mock(return_value=None)
>>> mock(1)
>>> mock(2)
>>> mock(3)
>>> mock(4)
>>> calls = [call(2), call(3)]
>>> mock.assert_has_calls(calls)
>>> calls = [call(4), call(2), call(3)]
>>> mock.assert_has_calls(calls, any_order=True)
Source: https://docs.python.org/3/library/unittest.mock.html#unittest.mock.Mock.assert_has_calls
How to install SQL Server Management Studio 2008 component only
SQL Server Management Studio 2008 R2 Express commandline:
The answer by dyslexicanaboko hits the crucial point, but this one is even simpler and suited for command line (unattended scenarios):
(tried out with SQL Server 2008 R2 Express, one instance installed and having downloaded SQLManagementStudio_x64_ENU.exe)
As pointed out in this thread often enough, it is better to use the original SQL server setup (e.g. SQL Express with Tools), if possible, but there are some scenarios, where you want to add SSMS at a SQL derivative without that tools, afterwards:
I´ve already put it in a batch syntax here:
@echo off
"%~dp0SQLManagementStudio_x64_ENU.exe" /Q /ACTION="Install" /FEATURES="SSMS" /IACCEPTSQLSERVERLICENSETERMS
Remarks:
For 2008 without R2 it should be enough to omit the /IACCEPTSQLSERVERLICENSETERMS flag, i guess.
The /INDICATEPROGRESS parameter is useless here, the whole command takes a number of minutes and is 100% silent without any acknowledgement. Just look at the start menu, if the command is ready, if it has succeeded.
This should work for the "ADV_SSMS" Feature (instead of "SSMS") too, which is the management studio extended variant (profiling, reporting, tuning, etc.)
Replace a value in a data frame based on a conditional (`if`) statement
stata.replace<-function(data,replacevar,replacevalue,ifs) {
ifs=parse(text=ifs)
yy=as.numeric(eval(ifs,data,parent.frame()))
x=sum(yy)
data=cbind(data,yy)
data[yy==1,replacevar]=replacevalue
message=noquote(paste0(x, " replacement are made"))
print(message)
return(data[,1:(ncol(data)-1)])
}
Call this function using below line.
d=stata.replace(d,"under20",1,"age<20")
How to install "ifconfig" command in my ubuntu docker image?
Please use the below command to get the IP address of the running container.
$ ip addr
Example-:
root@4c712d05922b:/# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
247: eth0@if248: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
link/ether 02:42:ac:11:00:06 brd ff:ff:ff:ff:ff:ff link-netnsid 0
inet 172.17.0.6/16 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::42:acff:fe11:6/64 scope link
valid_lft forever preferred_lft forever
GitHub Error Message - Permission denied (publickey)
I had the same issue recently. This might help if you need a fix immediately, but this needs to be done every time you re-start your system
From terminal, run : ssh-add ~/.ssh/id_rsa
Enter your system password and that should work.
How to convert enum value to int?
Sometime some C# approach makes the life easier in Java world..:
class XLINK {
static final short PAYLOAD = 102, ACK = 103, PAYLOAD_AND_ACK = 104;
}
//Now is trivial to use it like a C# enum:
int rcv = XLINK.ACK;
Using a remote repository with non-standard port
This avoids your problem rather than fixing it directly, but I'd recommend adding a ~/.ssh/config
file and having something like this
Host git_host
HostName git.host.de
User root
Port 4019
then you can have
url = git_host:/var/cache/git/project.git
and you can also ssh git_host
and scp git_host ...
and everything will work out.
How to make Toolbar transparent?
I implemented translucent Toolbar by creating two Theme.AppCompat.Light.NoActionBar
themes and setting colorPrimary
attribute to transparent color.
1) Create one theme for opaque Toolbar:
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Toolbar background color -->
<item name="colorPrimary">#ff212cff</item>
</style>
Second theme for transparent/overlay Toolbar:
<style name="AppTheme.Overlay" parent="AppTheme">
<item name="colorPrimary">@color/transparent</item>
</style>
2) In your activity layout, put Toolbar behind content so it can be displayed in front of it:
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<fragment
android:id="@+id/container"
android:name="com.test.CustomFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:minHeight="?attr/actionBarSize"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
</RelativeLayout>
3)
Apply the transparent theme to your acivity in AndroidManifest.xml
<activity
android:name="com.test.TransparentActivity"
android:parentActivityName="com.test.HomeActivity"
android:theme="@style/AppTheme.Overlay" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.test.HomeActivity" />
</activity>
Creating JSON on the fly with JObject
Neither dynamic
, nor JObject.FromObject
solution works when you have JSON properties that are not valid C# variable names e.g. "@odata.etag"
. I prefer the indexer initializer syntax in my test cases:
JObject jsonObject = new JObject
{
["Date"] = DateTime.Now,
["Album"] = "Me Against The World",
["Year"] = 1995,
["Artist"] = "2Pac"
};
Having separate set of enclosing symbols for initializing JObject
and for adding properties to it makes the index initializers more readable than classic object initializers, especially in case of compound JSON objects as below:
JObject jsonObject = new JObject
{
["Date"] = DateTime.Now,
["Album"] = "Me Against The World",
["Year"] = 1995,
["Artist"] = new JObject
{
["Name"] = "2Pac",
["Age"] = 28
}
};
With object initializer syntax, the above initialization would be:
JObject jsonObject = new JObject
{
{ "Date", DateTime.Now },
{ "Album", "Me Against The World" },
{ "Year", 1995 },
{ "Artist", new JObject
{
{ "Name", "2Pac" },
{ "Age", 28 }
}
}
};
Gradle to execute Java class (without modifying build.gradle)
Expanding on First Zero's answer, I'm guess you want something where you can also run gradle build
without errors.
Both gradle build
and gradle -PmainClass=foo runApp
work with this:
task runApp(type:JavaExec) {
classpath = sourceSets.main.runtimeClasspath
main = project.hasProperty("mainClass") ? project.getProperty("mainClass") : "package.MyDefaultMain"
}
where you set your default main class.
Assert that a method was called in a Python unit test
Yes, I can give you the outline but my Python is a bit rusty and I'm too busy to explain in detail.
Basically, you need to put a proxy in the method that will call the original, eg:
class fred(object):
def blog(self):
print "We Blog"
class methCallLogger(object):
def __init__(self, meth):
self.meth = meth
def __call__(self, code=None):
self.meth()
# would also log the fact that it invoked the method
#example
f = fred()
f.blog = methCallLogger(f.blog)
This StackOverflow answer about callable may help you understand the above.
In more detail:
Although the answer was accepted, due to the interesting discussion with Glenn and having a few minutes free, I wanted to enlarge on my answer:
# helper class defined elsewhere
class methCallLogger(object):
def __init__(self, meth):
self.meth = meth
self.was_called = False
def __call__(self, code=None):
self.meth()
self.was_called = True
#example
class fred(object):
def blog(self):
print "We Blog"
f = fred()
g = fred()
f.blog = methCallLogger(f.blog)
g.blog = methCallLogger(g.blog)
f.blog()
assert(f.blog.was_called)
assert(not g.blog.was_called)
How to tell if UIViewController's view is visible
For those of you looking for a Swift 2.2 version of the answer:
if self.isViewLoaded() && (self.view.window != nil) {
// viewController is visible
}
and Swift 3:
if self.isViewLoaded && (self.view.window != nil) {
// viewController is visible
}
Android: Test Push Notification online (Google Cloud Messaging)
Found a very easy way to do this.
Open http://phpfiddle.org/
Paste following php script in box. In php script set API_ACCESS_KEY, set device ids separated by coma.
Press F9 or click Run.
Have fun ;)
<?php
// API access key from Google API's Console
define( 'API_ACCESS_KEY', 'YOUR-API-ACCESS-KEY-GOES-HERE' );
$registrationIds = array("YOUR DEVICE IDS WILL GO HERE" );
// prep the bundle
$msg = array
(
'message' => 'here is a message. message',
'title' => 'This is a title. title',
'subtitle' => 'This is a subtitle. subtitle',
'tickerText' => 'Ticker text here...Ticker text here...Ticker text here',
'vibrate' => 1,
'sound' => 1
);
$fields = array
(
'registration_ids' => $registrationIds,
'data' => $msg
);
$headers = array
(
'Authorization: key=' . API_ACCESS_KEY,
'Content-Type: application/json'
);
$ch = curl_init();
curl_setopt( $ch,CURLOPT_URL, 'https://android.googleapis.com/gcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode( $fields ) );
$result = curl_exec($ch );
curl_close( $ch );
echo $result;
?>
For FCM, google url would be: https://fcm.googleapis.com/fcm/send
For FCM v1 google url would be: https://fcm.googleapis.com/v1/projects/YOUR_GOOGLE_CONSOLE_PROJECT_ID/messages:send
Note: While creating API Access Key on google developer console, you have to use 0.0.0.0/0 as ip address. (For testing purpose).
In case of receiving invalid Registration response from GCM server, please cross check the validity of your device token. You may check the validity of your device token using following url:
https://www.googleapis.com/oauth2/v1/tokeninfo?access_token=YOUR_DEVICE_TOKEN
Some response codes:
Following is the description of some response codes you may receive from server.
{ "message_id": "XXXX" } - success
{ "message_id": "XXXX", "registration_id": "XXXX" } - success, device registration id has been changed mainly due to app re-install
{ "error": "Unavailable" } - Server not available, resend the message
{ "error": "InvalidRegistration" } - Invalid device registration Id
{ "error": "NotRegistered"} - Application was uninstalled from the device
How to find where gem files are installed
Use gem environment
to find out about your gem environment:
RubyGems Environment:
- RUBYGEMS VERSION: 2.1.5
- RUBY VERSION: 2.0.0 (2013-06-27 patchlevel 247) [x86_64-darwin12.4.0]
- INSTALLATION DIRECTORY: /Users/ttm/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
- RUBY EXECUTABLE: /Users/ttm/.rbenv/versions/2.0.0-p247/bin/ruby
- EXECUTABLE DIRECTORY: /Users/ttm/.rbenv/versions/2.0.0-p247/bin
- SPEC CACHE DIRECTORY: /Users/ttm/.gem/specs
- RUBYGEMS PLATFORMS:
- ruby
- x86_64-darwin-12
- GEM PATHS:
- /Users/ttm/.rbenv/versions/2.0.0-p247/lib/ruby/gems/2.0.0
- /Users/ttm/.gem/ruby/2.0.0
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :backtrace => false
- :bulk_threshold => 1000
- REMOTE SOURCES:
- https://rubygems.org/
- SHELL PATH:
- /Users/ttm/.rbenv/versions/2.0.0-p247/bin
- /Users/ttm/.rbenv/libexec
- /Users/ttm/.rbenv/plugins/ruby-build/bin
- /Users/ttm/perl5/perlbrew/bin
- /Users/ttm/perl5/perlbrew/perls/perl-5.18.1/bin
- /Users/ttm/.pyenv/shims
- /Users/ttm/.pyenv/bin
- /Users/ttm/.rbenv/shims
- /Users/ttm/.rbenv/bin
- /Users/ttm/bin
- /usr/local/mysql-5.6.12-osx10.7-x86_64/bin
- /Users/ttm/libsmi/bin
- /usr/local/bin
- /usr/bin
- /bin
- /usr/sbin
- /sbin
- /usr/local/bin
Notice the two sections for:
INSTALLATION DIRECTORY
GEM PATHS
How to convert a structure to a byte array in C#?
I've come up with a different approach that could convert any struct
without the hassle of fixing length, however the resulting byte array would have a little bit more overhead.
Here is a sample struct
:
[StructLayout(LayoutKind.Sequential)]
public class HelloWorld
{
public MyEnum enumvalue;
public string reqtimestamp;
public string resptimestamp;
public string message;
public byte[] rawresp;
}
As you can see, all those structures would require adding the fixed length attributes. Which could often ended up taking up more space than required. Note that the LayoutKind.Sequential
is required, as we want reflection to always gives us the same order when pulling for FieldInfo
. My inspiration is from TLV
Type-Length-Value. Let's have a look at the code:
public static byte[] StructToByteArray<T>(T obj)
{
using (MemoryStream ms = new MemoryStream())
{
FieldInfo[] infos = typeof(T).GetFields(BindingFlags.Public | BindingFlags.Instance);
foreach (FieldInfo info in infos)
{
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream inms = new MemoryStream()) {
bf.Serialize(inms, info.GetValue(obj));
byte[] ba = inms.ToArray();
// for length
ms.Write(BitConverter.GetBytes(ba.Length), 0, sizeof(int));
// for value
ms.Write(ba, 0, ba.Length);
}
}
return ms.ToArray();
}
}
The above function simply uses the BinaryFormatter
to serialize the unknown size raw object
, and I simply keep track of the size as well and store it inside the output MemoryStream
too.
public static void ByteArrayToStruct<T>(byte[] data, out T output)
{
output = (T) Activator.CreateInstance(typeof(T), null);
using (MemoryStream ms = new MemoryStream(data))
{
byte[] ba = null;
FieldInfo[] infos = typeof(T).GetFields(BindingFlags.Public | BindingFlags.Instance);
foreach (FieldInfo info in infos)
{
// for length
ba = new byte[sizeof(int)];
ms.Read(ba, 0, sizeof(int));
// for value
int sz = BitConverter.ToInt32(ba, 0);
ba = new byte[sz];
ms.Read(ba, 0, sz);
BinaryFormatter bf = new BinaryFormatter();
using (MemoryStream inms = new MemoryStream(ba))
{
info.SetValue(output, bf.Deserialize(inms));
}
}
}
}
When we want to convert it back to its original struct
we simply read the length back and directly dump it back into the BinaryFormatter
which in turn dump it back into the struct
.
These 2 functions are generic and should work with any struct
, I've tested the above code in my C#
project where I have a server and a client, connected and communicate via NamedPipeStream
and I forward my struct
as byte array from one and to another and converted it back.
I believe my approach might be better, since it doesn't fix length on the struct
itself and the only overhead is just an int
for every fields you have in your struct. There are also some tiny bit overhead inside the byte array generated by BinaryFormatter
, but other than that, is not much.
How to send control+c from a bash script?
ctrl+c and kill -INT <pid>
are not exactly the same, to emulate ctrl+c we need to first understand the difference.
kill -INT <pid>
will send the INT
signal to a given process (found with its pid
).
ctrl+c is mapped to the intr
special character which when received by the terminal should send INT
to the foreground process group of that terminal. You can emulate that by targetting the group of your given <pid>
. It can be done by prepending a -
before the signal in the kill command. Hence the command you want is:
kill -INT -<pid>
You can test it pretty easily with a script:
#!/usr/bin/env ruby
fork {
trap(:INT) {
puts 'signal received in child!'
exit
}
sleep 1_000
}
puts "run `kill -INT -#{Process.pid}` in any other terminal window."
Process.wait
Sources:
Reset the Value of a Select Box
I presume you only want to reset a single element. Resetting an entire form is simple: call its reset method.
The easiest way to "reset" a select element is to set its selectedIndex
property to the default value. If you know that no option is the default selected option, just set the select elemen'ts selectedIndex property to an appropriate value:
function resetSelectElement(selectElement) {
selecElement.selectedIndex = 0; // first option is selected, or
// -1 for no option selected
}
However, since one option may have the selected attribtue or otherwise be set to the default selected option, you may need to do:
function resetSelectElement(selectElement) {
var options = selectElement.options;
// Look for a default selected option
for (var i=0, iLen=options.length; i<iLen; i++) {
if (options[i].defaultSelected) {
selectElement.selectedIndex = i;
return;
}
}
// If no option is the default, select first or none as appropriate
selectElement.selectedIndex = 0; // or -1 for no option selected
}
And beware of setting attributes rather than properties, they have different effects in different browsers.
How do I find a list of Homebrew's installable packages?
brew help
will show you the list of commands that are available.
brew list
will show you the list of installed packages. You can also append formulae, for example brew list postgres
will tell you of files installed by postgres (providing it is indeed installed).
brew search <search term>
will list the possible packages that you can install. brew search post
will return multiple packages that are available to install that have post in their name.
brew info <package name>
will display some basic information about the package in question.
You can also search http://searchbrew.com or https://brewformulas.org (both sites do basically the same thing)
LEFT OUTER JOIN in LINQ
Simple solution for the LEFT OUTER JOIN:
var setA = context.SetA;
var setB = context.SetB.Select(st=>st.Id).Distinct().ToList();
var leftOuter = setA.Where(stA=> !setB.Contains(stA.Id));
notes:
- To improve performance SetB could be converted to a Dictionary (if that is done then you have to change this: !setB.Contains(stA.Id)) or a HashSet
- When there is more than one field involved this could be achieve using Set operations and a class that implement: IEqualityComparer
How to create UILabel programmatically using Swift?
override func viewDidLoad()
{
super.viewDidLoad()
var label = UILabel(frame: CGRectMake(0, 0, 200, 21))
label.center = CGPointMake(160, 284)
label.textAlignment = NSTextAlignment.Center
label.text = "I'm a test label"
self.view.addSubview(label)
}
Swift 3.0+ Update:
let label = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 21))
label.center = CGPoint(x: 160, y: 285)
label.textAlignment = .center
label.text = "I'm a test label"
self.view.addSubview(label)
show more/Less text with just HTML and JavaScript
My answer is similar but different, there are a few ways to achieve toggling effect. I guess it depends on your circumstance. This may not be the best way for you in the end.
The missing piece you've been looking for is to create an if
statement. This allows for you to toggle your text.
More on if statements here.
JSFiddle: http://jsfiddle.net/8u2jF/
Javascript:
var status = "less";
function toggleText()
{
var text="Here is some text that I want added to the HTML file";
if (status == "less") {
document.getElementById("textArea").innerHTML=text;
document.getElementById("toggleButton").innerText = "See Less";
status = "more";
} else if (status == "more") {
document.getElementById("textArea").innerHTML = "";
document.getElementById("toggleButton").innerText = "See More";
status = "less"
}
}
What is the difference between an abstract function and a virtual function?
I made this simpler by making some improvements on the following classes (from other answers):
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace TestOO
{
class Program
{
static void Main(string[] args)
{
BaseClass _base = new BaseClass();
Console.WriteLine("Calling virtual method directly");
_base.SayHello();
Console.WriteLine("Calling single method directly");
_base.SayGoodbye();
DerivedClass _derived = new DerivedClass();
Console.WriteLine("Calling new method from derived class");
_derived.SayHello();
Console.WriteLine("Calling overrided method from derived class");
_derived.SayGoodbye();
DerivedClass2 _derived2 = new DerivedClass2();
Console.WriteLine("Calling new method from derived2 class");
_derived2.SayHello();
Console.WriteLine("Calling overrided method from derived2 class");
_derived2.SayGoodbye();
Console.ReadLine();
}
}
public class BaseClass
{
public void SayHello()
{
Console.WriteLine("Hello\n");
}
public virtual void SayGoodbye()
{
Console.WriteLine("Goodbye\n");
}
public void HelloGoodbye()
{
this.SayHello();
this.SayGoodbye();
}
}
public abstract class AbstractClass
{
public void SayHello()
{
Console.WriteLine("Hello\n");
}
//public virtual void SayGoodbye()
//{
// Console.WriteLine("Goodbye\n");
//}
public abstract void SayGoodbye();
}
public class DerivedClass : BaseClass
{
public new void SayHello()
{
Console.WriteLine("Hi There");
}
public override void SayGoodbye()
{
Console.WriteLine("See you later");
}
}
public class DerivedClass2 : AbstractClass
{
public new void SayHello()
{
Console.WriteLine("Hi There");
}
// We should use the override keyword with abstract types
//public new void SayGoodbye()
//{
// Console.WriteLine("See you later2");
//}
public override void SayGoodbye()
{
Console.WriteLine("See you later");
}
}
}
How do I detect if software keyboard is visible on Android Device or not?
I used this as a basis: https://rogerkeays.com/how-to-check-if-the-software-keyboard-is-shown-in-android
/**
* To capture the result of IMM hide/show soft keyboard
*/
public class IMMResult extends ResultReceiver {
public int result = -1;
public IMMResult() {
super(null);
}
@Override
public void onReceiveResult(int r, Bundle data) {
result = r;
}
// poll result value for up to 500 milliseconds
public int getResult() {
try {
int sleep = 0;
while (result == -1 && sleep < 500) {
Thread.sleep(100);
sleep += 100;
}
} catch (InterruptedException e) {
Log.e("IMMResult", e.getMessage());
}
return result;
}
}
Then wrote this method:
public boolean isSoftKeyboardShown(InputMethodManager imm, View v) {
IMMResult result = new IMMResult();
int res;
imm.showSoftInput(v, 0, result);
// if keyboard doesn't change, handle the keypress
res = result.getResult();
if (res == InputMethodManager.RESULT_UNCHANGED_SHOWN ||
res == InputMethodManager.RESULT_UNCHANGED_HIDDEN) {
return true;
}
else
return false;
}
You may then use this to test all fields (EditText, AutoCompleteTextView, etc) that may have opened a softkeyboard:
InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
if(isSoftKeyboardShown(imm, editText1) | isSoftKeyboardShown(imm, autocompletetextview1))
//close the softkeyboard
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
Addmittely not an ideal solution, but it gets the job done.
The difference between Classes, Objects, and Instances
The concept behind classes and objects is to encapsulate logic into single programming unit. Classes are the blueprints of which objects are created.
Here an example of a class representing a Car:
public class Car {
int currentSpeed;
String name;
public void accelerate() {
}
public void park() {
}
public void printCurrentSpeed() {
}
}
You can create instances of the object Car like this:
Car audi = new Car();
Car toyota = new Car();
I have taken the example from this tutorial
MySQL query to get column names?
i no expert, but this works for me..
$sql = "desc MyTable";
$result = @mysql_query($sql);
while($row = @mysql_fetch_array($result)){
echo $row[0]."<br>"; // returns the first column of array. in this case Field
// the below code will return a full array-> Field,Type,Null,Key,Default,Extra
// for ($c=0;$c<sizeof($row);$c++){echo @$row[$c]."<br>";}
}
Technically what is the main difference between Oracle JDK and OpenJDK?
Technical differences are a consequence of the goal of each one (OpenJDK is meant to be the reference implementation, open to the community, while Oracle is meant to be a commercial one)
They both have "almost" the same code of the classes in the Java API; but the code for the virtual machine itself is actually different, and when it comes to libraries, OpenJDK tends to use open libraries while Oracle tends to use closed ones; for instance, the font library.
ng-mouseover and leave to toggle item using mouse in angularjs
I would simply make the assignment happen in the ng-mouseover and ng-mouseleave; no need to bother js file :)
<ul ng-repeat="task in tasks">
<li ng-mouseover="hoverEdit = true" ng-mouseleave="hoverEdit = false">{{task.name}}</li>
<span ng-show="hoverEdit"><a>Edit</a></span>
</ul>
Android - setOnClickListener vs OnClickListener vs View.OnClickListener
View is the superclass for all widgets and the OnClickListener interface belongs to this class. All widgets inherit this. View.OnClickListener is the same as OnClickListener. You would have to override the onClick(View view) method from this listener to achieve the action that you want for your button.
To tell Android to listen to click events for a widget, you need to do:
widget.setOnClickListener(this); // If the containing class implements the interface
// Or you can do the following to set it for each widget individually
widget.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Do something here
}
});
The 'View' parameter passed in the onClick() method simply lets Android know that a view has been clicked. It can be a Button or a TextView or something else. It is up to you to set an OnClickListener for every widget or to simply make the class containing all these widgets implement the interface. In this case you will have a common onClick() method for all the widgets and all you have to do is to check the id of the view that is passed into the method and then match that against the id for each element that you want and take action for that element.
.attr('checked','checked') does not work
With jQuery, never use inline onclick
javascript. Keep it unobtrusive. Do this instead, and remove the onclick
completely.
Also, note the use of the :checked
pseudo selector in the last line. The reason for this is because once the page is loaded, the html and the actual state of the form element can be different. Open a web inspector and you can click on the other radio button and the HTML will still show the first one is checked. The :checked
selector instead filters elements that are actually checked, regardless of what the html started as.
$('button').click(function() {
alert($('input[name="myname"][value="b"]').length);
$('input[name="myname"][value="b"]').attr('checked','checked');
$('#b').attr('checked',true);
alert($('input[name="myname"]:checked').val());
});
http://jsfiddle.net/uL545/1/
How to use gitignore command in git
git ignore is a convention in git. Setting a file by the name of .gitignore
will ignore the files in that directory and deeper directories that match the
patterns that the file contains. The most common use is just to have one file
like this at the top level. But you can add others deeper in your directory
structure to ignore even more patterns or stop ignoring them for that directory
and subsequently deeper ones.
Likewise, you can "unignore" certain files in a deeper structure or a specific
subset (ie, you ignore *.log but want to still track important.log) by
specifying patterns beginning with !
. eg:
*.log !important.log
will ignore all log files but will track files named important.log
If you are tracking files you meant to ignore, delete them, add the pattern to
you .gitignore file and add all the changes
# delete files that should be ignored, or untrack them with
# git rm --cached <file list or pattern>
# stage all the changes git commit
git add -A
from now on your repository will not have them tracked.
If you would like to clean up your history, you can
# if you want to correct the last 10 commits
git rebase -i --preserve-merges HEAD~10
then mark each commit with e
or edit
. Save the plan. Now git will replay
your history stopping at each commit you marked with e. Here you delete the
files you don't want, git add -A
and then git rebase --continue
until you
are done. Your history will be clean. Make sure you tell you coworkers as you
will have to force push and they will have to rebase what they didn't push yet.
How to create an Array, ArrayList, Stack and Queue in Java?
I am guessing you're confused with the parameterization of the types:
// This works, because there is one class/type definition in the parameterized <> field
ArrayList<String> myArrayList = new ArrayList<String>();
// This doesn't work, as you cannot use primitive types here
ArrayList<char> myArrayList = new ArrayList<char>();
How to properly stop the Thread in Java?
For synchronizing threads I prefer using CountDownLatch
which helps threads to wait until the process being performed complete. In this case, the worker class is set up with a CountDownLatch
instance with a given count. A call to await
method will block until the current count reaches zero due to invocations of the countDown
method or the timeout set is reached. This approach allows interrupting a thread instantly without having to wait for the specified waiting time to elapse:
public class IndexProcessor implements Runnable {
private static final Logger LOGGER = LoggerFactory.getLogger(IndexProcessor.class);
private final CountDownLatch countdownlatch;
public IndexProcessor(CountDownLatch countdownlatch) {
this.countdownlatch = countdownlatch;
}
public void run() {
try {
while (!countdownlatch.await(15000, TimeUnit.MILLISECONDS)) {
LOGGER.debug("Processing...");
}
} catch (InterruptedException e) {
LOGGER.error("Exception", e);
run = false;
}
}
}
When you want to finish execution of the other thread, execute countDown on the CountDownLatch
and join
the thread to the main thread:
public class SearchEngineContextListener implements ServletContextListener {
private static final Logger LOGGER = LoggerFactory.getLogger(SearchEngineContextListener.class);
private Thread thread = null;
private IndexProcessor runnable = null;
private CountDownLatch countdownLatch = null;
@Override
public void contextInitialized(ServletContextEvent event) {
countdownLatch = new CountDownLatch(1);
Thread thread = new Thread(new IndexProcessor(countdownLatch));
LOGGER.debug("Starting thread: " + thread);
thread.start();
LOGGER.debug("Background process successfully started.");
}
@Override
public void contextDestroyed(ServletContextEvent event) {
LOGGER.debug("Stopping thread: " + thread);
if (countdownLatch != null)
{
countdownLatch.countDown();
}
if (thread != null) {
try {
thread.join();
} catch (InterruptedException e) {
LOGGER.error("Exception", e);
}
LOGGER.debug("Thread successfully stopped.");
}
}
}
Get source JARs from Maven repository
If a project creates a jar of the project sources and deploys it to a maven repository, then you'll find it :)
Just FYI, sources artifacts are generally created by the maven-source-plugin. This plugin can bundle the main or test sources of a project into a jar archive and, as explained in Configuring Source Plugin:
(...) The generated jar file will be named by the value of the finalName
plus "-sources" if it is the main sources. Otherwise, it would be finalName
plus "-test-sources" if it is the test sources.
The additional text was given to describe an artifact ("-sources" or "-test-sources" here) is called a classifier.
To declare a dependency on an artifact that uses a classifier, simply add the <classifier>
element. For example:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate</artifactId>
<version>3.2.7.ga</version>
<classifier>sources</classifier>
</dependency>
Note that you generally don't do this, most IDEs provide support to download sources (and/or JavaDoc) from the main artifact without declaring explicitly a dependency on them.
Finally, also note that some repository search engines allow searching for artifacts using the classifier (at least Nexus does with the advanced search). See this search for example.
AngularJS - ng-if check string empty value
This is what may be happening, if the value of item.photo
is undefined then item.photo != ''
will always show as true. And if you think logically it actually makes sense, item.photo
is not an empty string (so this condition comes true) since it is undefined
.
Now for people who are trying to check if the value of input is empty or not in Angular 6, can go by this approach.
Lets say this is the input field -
_x000D_
_x000D_
<input type="number" id="myTextBox" name="myTextBox"_x000D_
[(ngModel)]="response.myTextBox"_x000D_
#myTextBox="ngModel">
_x000D_
_x000D_
_x000D_
To check if the field is empty or not this should be the script.
_x000D_
_x000D_
<div *ngIf="!myTextBox.value" style="color:red;">_x000D_
Your field is empty_x000D_
</div>
_x000D_
_x000D_
_x000D_
Do note the subtle difference between the above answer and this answer. I have added an additional attribute .value
after my input name myTextBox
.
I don't know if the above answer worked for above version of Angular, but for Angular 6 this is how it should be done.
How can I write to the console in PHP?
There is also a great Google Chrome extension, PHP Console, with a PHP library that allows you to:
- See errors and exceptions in the Chrome JavaScript console and in the notification popups.
- Dump any type of variable.
- Execute PHP code remotely.
- Protect access by password.
- Group console logs by request.
- Jump to
error file:line
in your text editor.
- Copy error/debug data to the clipboard (for testers).
Open a Web Page in a Windows Batch FIle
Unfortunately, the best method to approach this is to use Internet Explorer as it's a browser that is guaranteed to be on Windows based machines. This will also bring compatibility of other users which might have alternative browsers such as Firefox, Chrome, Opera..etc,
start "iexplore.exe" http://www.website.com
Filtering collections in C#
Here is a code block / example of some list filtering using three different methods that I put together to show Lambdas and LINQ based list filtering.
#region List Filtering
static void Main(string[] args)
{
ListFiltering();
Console.ReadLine();
}
private static void ListFiltering()
{
var PersonList = new List<Person>();
PersonList.Add(new Person() { Age = 23, Name = "Jon", Gender = "M" }); //Non-Constructor Object Property Initialization
PersonList.Add(new Person() { Age = 24, Name = "Jack", Gender = "M" });
PersonList.Add(new Person() { Age = 29, Name = "Billy", Gender = "M" });
PersonList.Add(new Person() { Age = 33, Name = "Bob", Gender = "M" });
PersonList.Add(new Person() { Age = 45, Name = "Frank", Gender = "M" });
PersonList.Add(new Person() { Age = 24, Name = "Anna", Gender = "F" });
PersonList.Add(new Person() { Age = 29, Name = "Sue", Gender = "F" });
PersonList.Add(new Person() { Age = 35, Name = "Sally", Gender = "F" });
PersonList.Add(new Person() { Age = 36, Name = "Jane", Gender = "F" });
PersonList.Add(new Person() { Age = 42, Name = "Jill", Gender = "F" });
//Logic: Show me all males that are less than 30 years old.
Console.WriteLine("");
//Iterative Method
Console.WriteLine("List Filter Normal Way:");
foreach (var p in PersonList)
if (p.Gender == "M" && p.Age < 30)
Console.WriteLine(p.Name + " is " + p.Age);
Console.WriteLine("");
//Lambda Filter Method
Console.WriteLine("List Filter Lambda Way");
foreach (var p in PersonList.Where(p => (p.Gender == "M" && p.Age < 30))) //.Where is an extension method
Console.WriteLine(p.Name + " is " + p.Age);
Console.WriteLine("");
//LINQ Query Method
Console.WriteLine("List Filter LINQ Way:");
foreach (var v in from p in PersonList
where p.Gender == "M" && p.Age < 30
select new { p.Name, p.Age })
Console.WriteLine(v.Name + " is " + v.Age);
}
private class Person
{
public Person() { }
public int Age { get; set; }
public string Name { get; set; }
public string Gender { get; set; }
}
#endregion
MongoDB "root" user
Mongodb user management:
roles list:
read
readWrite
dbAdmin
userAdmin
clusterAdmin
readAnyDatabase
readWriteAnyDatabase
userAdminAnyDatabase
dbAdminAnyDatabase
create user:
db.createUser(user, writeConcern)
db.createUser({ user: "user",
pwd: "pass",
roles: [
{ role: "read", db: "database" }
]
})
update user:
db.updateUser("user",{
roles: [
{ role: "readWrite", db: "database" }
]
})
drop user:
db.removeUser("user")
or
db.dropUser("user")
view users:
db.getUsers();
more information: https://docs.mongodb.com/manual/reference/security/#read
How to print multiple variable lines in Java
You can create Class Person
with fields firstName
and lastName
and define method toString()
. Here I created a util method which returns String presentation of a Person
object.
This is a sample
Main
public class Main {
public static void main(String[] args) {
Person person = generatePerson();
String personStr = personToString(person);
System.out.println(personStr);
}
private static Person generatePerson() {
String firstName = "firstName";//generateFirstName();
String lastName = "lastName";//generateLastName;
return new Person(firstName, lastName);
}
/*
You can even put this method into a separate util class.
*/
private static String personToString(Person person) {
return person.getFirstName() + "\n" + person.getLastName();
}
}
Person
public class Person {
private String firstName;
private String lastName;
//getters, setters, constructors.
}
I prefer a separate util method to toString()
, because toString()
is used for debug.
https://stackoverflow.com/a/3615741/4587961
I had experience writing programs with many outputs: HTML UI, excel or txt file, console. They may need different object presentation, so I created a util class which builds a String depending on the output.
How to launch Safari and open URL from iOS app
Here's what I did:
I created an IBAction in the header .h files as follows:
- (IBAction)openDaleDietrichDotCom:(id)sender;
I added a UIButton on the Settings page containing the text that I want to link to.
I connected the button to IBAction in File Owner appropriately.
Then implement the following:
Objective-C
- (IBAction)openDaleDietrichDotCom:(id)sender {
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://www.daledietrich.com"]];
}
Swift
(IBAction in viewController, rather than header file)
if let link = URL(string: "https://yoursite.com") {
UIApplication.shared.open(link)
}
Difference between binary semaphore and mutex
The answer may depend on the target OS. For example, at least one RTOS implementation I'm familiar with will allow multiple sequential "get" operations against a single OS mutex, so long as they're all from within the same thread context. The multiple gets must be replaced by an equal number of puts before another thread will be allowed to get the mutex. This differs from binary semaphores, for which only a single get is allowed at a time, regardless of thread contexts.
The idea behind this type of mutex is that you protect an object by only allowing a single context to modify the data at a time. Even if the thread gets the mutex and then calls a function that further modifies the object (and gets/puts the protector mutex around its own operations), the operations should still be safe because they're all happening under a single thread.
{
mutexGet(); // Other threads can no longer get the mutex.
// Make changes to the protected object.
// ...
objectModify(); // Also gets/puts the mutex. Only allowed from this thread context.
// Make more changes to the protected object.
// ...
mutexPut(); // Finally allows other threads to get the mutex.
}
Of course, when using this feature, you must be certain that all accesses within a single thread really are safe!
I'm not sure how common this approach is, or whether it applies outside of the systems with which I'm familiar. For an example of this kind of mutex, see the ThreadX RTOS.
Number of days in particular month of particular year?
Code for java.util.Calendar
If you have to use java.util.Calendar
, I suspect you want:
int days = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
Code for Joda Time
Personally, however, I'd suggest using Joda Time instead of java.util.{Calendar, Date}
to start with, in which case you could use:
int days = chronology.dayOfMonth().getMaximumValue(date);
Note that rather than parsing the string values individually, it would be better to get whichever date/time API you're using to parse it. In java.util.*
you might use SimpleDateFormat
; in Joda Time you'd use a DateTimeFormatter
.
What is the Git equivalent for revision number?
Consider to use
Gives information about Git repository revision in format like master-c73-gabc6bec
.
Can fill template string or file with environment variables and information from Git.
Useful to provide information about version of the program: branch, tag, commit hash,
commits count, dirty status, date and time. One of the most useful things is count of
commits, not taking into account merged branches - only first parent.
phpexcel to download
Instead of saving it to a file, save it to php://output
Docs:
$objWriter->save('php://output');
This will send it AS-IS to the browser.
You want to add some headersDocs first, like it's common with file downloads, so the browser knows which type that file is and how it should be named (the filename):
// We'll be outputting an excel file
header('Content-type: application/vnd.ms-excel');
// It will be called file.xls
header('Content-Disposition: attachment; filename="file.xls"');
// Write file to the browser
$objWriter->save('php://output');
First do the headers, then the save. For the excel headers see as well the following question: Setting mime type for excel document.
ViewPager PagerAdapter not updating the View
The code below worked for me.
Create a class which extends the FragmentPagerAdapter class as below.
public class Adapter extends FragmentPagerAdapter {
private int tabCount;
private Activity mActivity;
private Map<Integer, String> mFragmentTags;
private FragmentManager mFragmentManager;
private int container_id;
private ViewGroup container;
private List<Object> object;
public Adapter(FragmentManager fm) {
super(fm);
}
public Adapter(FragmentManager fm, int numberOfTabs , Activity mA) {
super(fm);
mActivity = mA;
mFragmentManager = fm;
object = new ArrayList<>();
mFragmentTags = new HashMap<Integer, String>();
this.tabCount = numberOfTabs;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return Fragment0.newInstance(mActivity);
case 1:
return Fragment1.newInstance(mActivity);
case 2:
return Fragment2.newInstance(mActivity);
default:
return null;
}}
@Override
public Object instantiateItem(ViewGroup container, int position) {
Object object = super.instantiateItem(container, position);
if (object instanceof Fragment) {
Log.e("Already defined","Yes");
Fragment fragment = (Fragment) object;
String tag = fragment.getTag();
Log.e("Fragment Tag","" + position + ", " + tag);
mFragmentTags.put(position, tag);
}else{
Log.e("Already defined","No");
}
container_id = container.getId();
this.container = container;
if(position == 0){
this.object.add(0,object);
}else if(position == 1){
this.object.add(1,object);
}else if(position == 2){
this.object.add(2,object);
}
return object;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
if (object instanceof Fragment) {
Log.e("Removed" , String.valueOf(position));
}
}
@Override
public int getItemPosition (Object object)
{ int index = 0;
if(this.object.get(0) == object){
index = 0;
}else if(this.object.get(1) == object){
index = 1;
}else if(this.object.get(2) == object){
index = 2;
}else{
index = -1;
}
Log.e("Index" , "..................." + String.valueOf(index));
if (index == -1)
return POSITION_NONE;
else
return index;
}
public String getFragmentTag(int pos){
return "android:switcher:"+R.id.pager+":"+pos;
}
public void NotifyDataChange(){
this.notifyDataSetChanged();
}
public int getcontainerId(){
return container_id;
}
public ViewGroup getContainer(){
return this.container;
}
public List<Object> getObject(){
return this.object;
}
@Override
public int getCount() {
return tabCount;
}}
Then inside each Fragment you created, create an updateFragment method. In this method you change the things you need to change in the fragment. For example in my case, Fragment0 contained a GLSurfaceView which displays a 3d object based on a path to a .ply file, so inside my updateFragment method I change the path to this ply file.
then create a ViewPager instance,
viewPager = (ViewPager) findViewById(R.id.pager);
and an Adpater instance,
adapter = new Adapter(getSupportFragmentManager(), 3, this);
then do this,
viewPager.setAdapter(adapter);
viewPager.setOffscreenPageLimit(1);
Then inside the class were you initialized the Adapter class above and created a viewPager, every time you want to update one of your fragments (in our case Fragment0) use the following:
adapter.NotifyDataChange();
adapter.destroyItem(adapter.getContainer(), 0, adapter.getObject().get(0)); // destroys page 0 in the viewPager.
fragment0 = (Fragment0) getSupportFragmentManager().findFragmentByTag(adapter.getFragmentTag(0)); // Gets fragment instance used on page 0.
fragment0.updateFragment() method which include the updates on this fragment
adapter.instantiateItem(adapter.getContainer(), 0); // re-initialize page 0.
This solution was based on the technique suggested by Alvaro Luis Bustamante.
generate a random number between 1 and 10 in c
You need a different seed at every execution.
You can start to call at the beginning of your program:
srand(time(NULL));
Note that % 10
yields a result from 0
to 9
and not from 1
to 10
: just add 1
to your %
expression to get 1
to 10
.
using mailto to send email with an attachment
this is not possible in "mailto" function.
please go with server side coding(C#).make sure open vs in administrative permission.
Microsoft.Office.Interop.Outlook.Application oApp = new Microsoft.Office.Interop.Outlook.Application();
Microsoft.Office.Interop.Outlook.MailItem oMsg = (Microsoft.Office.Interop.Outlook.MailItem)oApp.CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olMailItem);
oMsg.Subject = "emailSubject";
oMsg.BodyFormat = Microsoft.Office.Interop.Outlook.OlBodyFormat.olFormatHTML;
oMsg.BCC = "emailBcc";
oMsg.To = "emailRecipient";
string body = "emailMessage";
oMsg.HTMLBody = "body";
oMsg.Attachments.Add(Convert.ToString(@"/my_location_virtual_path/myfile.txt"), Microsoft.Office.Interop.Outlook.OlAttachmentType.olByValue, Type.Missing, Type.Missing);
oMsg.Display(false); //In order to displ
How do I plot only a table in Matplotlib?
This is another option to write a pandas dataframe directly into a matplotlib table:
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
# hide axes
fig.patch.set_visible(False)
ax.axis('off')
ax.axis('tight')
df = pd.DataFrame(np.random.randn(10, 4), columns=list('ABCD'))
ax.table(cellText=df.values, colLabels=df.columns, loc='center')
fig.tight_layout()
plt.show()
Angular and debounce
If you don't want to deal with @angular/forms
, you can just use an RxJS Subject
with change bindings.
view.component.html
<input [ngModel]='model' (ngModelChange)='changed($event)' />
view.component.ts
import { Subject } from 'rxjs/Subject';
import { Component } from '@angular/core';
import 'rxjs/add/operator/debounceTime';
export class ViewComponent {
model: string;
modelChanged: Subject<string> = new Subject<string>();
constructor() {
this.modelChanged
.debounceTime(300) // wait 300ms after the last event before emitting last event
.distinctUntilChanged() // only emit if value is different from previous value
.subscribe(model => this.model = model);
}
changed(text: string) {
this.modelChanged.next(text);
}
}
This does trigger change detection. For a way that doesn't trigger change detection, check out Mark's answer.
Update
.pipe(debounceTime(300), distinctUntilChanged())
is needed for rxjs 6.
Example:
constructor() {
this.modelChanged.pipe(
debounceTime(300),
distinctUntilChanged())
.subscribe(model => this.model = model);
}
Adding Git-Bash to the new Windows Terminal
Change the profiles parameter to "commandline": "%PROGRAMFILES%\\Git\\bin\\bash.exe -l -i"
This works for me and allows for my .bash_profile alias autocomplete scripts to run.
What does the "__block" keyword mean?
It tells the compiler that any variable marked by it must be treated in a special way when it is used inside a block. Normally, variables and their contents that are also used in blocks are copied, thus any modification done to these variables don't show outside the block. When they are marked with __block
, the modifications done inside the block are also visible outside of it.
For an example and more info, see The __block Storage Type in Apple's Blocks Programming Topics.
The important example is this one:
extern NSInteger CounterGlobal;
static NSInteger CounterStatic;
{
NSInteger localCounter = 42;
__block char localCharacter;
void (^aBlock)(void) = ^(void) {
++CounterGlobal;
++CounterStatic;
CounterGlobal = localCounter; // localCounter fixed at block creation
localCharacter = 'a'; // sets localCharacter in enclosing scope
};
++localCounter; // unseen by the block
localCharacter = 'b';
aBlock(); // execute the block
// localCharacter now 'a'
}
In this example, both localCounter
and localCharacter
are modified before the block is called. However, inside the block, only the modification to localCharacter
would be visible, thanks to the __block
keyword. Conversely, the block can modify localCharacter
and this modification is visible outside of the block.
Real time face detection OpenCV, Python
Your line:
img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
will draw a rectangle in the image, but the return value will be None, so img changes to None and cannot be drawn.
Try
cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
Java reflection: how to get field value from an object, not knowing its class
public abstract class Refl {
/** Use: Refl.<TargetClass>get(myObject,"x.y[0].z"); */
public static<T> T get(Object obj, String fieldPath) {
return (T) getValue(obj, fieldPath);
}
public static Object getValue(Object obj, String fieldPath) {
String[] fieldNames = fieldPath.split("[\\.\\[\\]]");
String success = "";
Object res = obj;
for (String fieldName : fieldNames) {
if (fieldName.isEmpty()) continue;
int index = toIndex(fieldName);
if (index >= 0) {
try {
res = ((Object[])res)[index];
} catch (ClassCastException cce) {
throw new RuntimeException("cannot cast "+res.getClass()+" object "+res+" to array, path:"+success, cce);
} catch (IndexOutOfBoundsException iobe) {
throw new RuntimeException("bad index "+index+", array size "+((Object[])res).length +" object "+res +", path:"+success, iobe);
}
} else {
Field field = getField(res.getClass(), fieldName);
field.setAccessible(true);
try {
res = field.get(res);
} catch (Exception ee) {
throw new RuntimeException("cannot get value of ["+fieldName+"] from "+res.getClass()+" object "+res +", path:"+success, ee);
}
}
success += fieldName + ".";
}
return res;
}
public static Field getField(Class<?> clazz, String fieldName) {
Class<?> tmpClass = clazz;
do {
try {
Field f = tmpClass.getDeclaredField(fieldName);
return f;
} catch (NoSuchFieldException e) {
tmpClass = tmpClass.getSuperclass();
}
} while (tmpClass != null);
throw new RuntimeException("Field '" + fieldName + "' not found in class " + clazz);
}
private static int toIndex(String s) {
int res = -1;
if (s != null && s.length() > 0 && Character.isDigit(s.charAt(0))) {
try {
res = Integer.parseInt(s);
if (res < 0) {
res = -1;
}
} catch (Throwable t) {
res = -1;
}
}
return res;
}
}
It supports fetching fields and array items, e.g.:
System.out.println(""+Refl.getValue(b,"x.q[0].z.y"));
there is no difference between dots and braces, they are just delimiters, and empty field names are ignored:
System.out.println(""+Refl.getValue(b,"x.q[0].z.y[value]"));
System.out.println(""+Refl.getValue(b,"x.q.1.y.z.value"));
System.out.println(""+Refl.getValue(b,"x[q.1]y]z[value"));
Can you force Visual Studio to always run as an Administrator in Windows 8?
Just find the program in Program Files directory (or in other location). Right click on the EXE file, on the second tab at the bottom check the checkbox of forcing running that program with administration privileges.
From now all shortcuts of the exe file will be fired with administration privileges :)
Changing the position of Bootstrap popovers based on the popover's X position in relation to window edge?
I just noticed that the placement option could either be a string or a function returning a string that makes the calculation each time you click on a popover-able link.
This makes it real easy to replicate what you did without the initial $.each function:
var options = {
placement: function (context, source) {
var position = $(source).position();
if (position.left > 515) {
return "left";
}
if (position.left < 515) {
return "right";
}
if (position.top < 110){
return "bottom";
}
return "top";
}
, trigger: "click"
};
$(".infopoint").popover(options);
get current url in twig template?
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) %}
The app
global view variable contains all sorts of useful shortcuts, such as app.session
and app.security.token.user
, that reference the services you might use in a controller.
Extract a page from a pdf as a jpeg
One problem,everyone will face that is to Install Poppler.My way is a tricky way,but will work efficiently.1st download Poppler here.Then Extract it add In the code section just add poppler_path=r'C:\Program Files\poppler-0.68.0\bin'(for eg.) like below
from pdf2image import convert_from_path
images = convert_from_path("mypdf.pdf", 500,poppler_path=r'C:\Program Files\poppler-0.68.0\bin')
for i, image in enumerate(images):
fname = 'image'+str(i)+'.png'
image.save(fname, "PNG")
break/exit script
This is an old question but there is no a clean solution yet. This probably is not answering this specific question, but those looking for answers on 'how to gracefully exit from an R script' will probably land here. It seems that R developers forgot to implement an exit() function. Anyway, the trick I've found is:
continue <- TRUE
tryCatch({
# You do something here that needs to exit gracefully without error.
...
# We now say bye-bye
stop("exit")
}, error = function(e) {
if (e$message != "exit") {
# Your error message goes here. E.g.
stop(e)
}
continue <<-FALSE
})
if (continue) {
# Your code continues here
...
}
cat("done.\n")
Basically, you use a flag to indicate the continuation or not of a specified block of code. Then you use the stop()
function to pass a customized message to the error handler of a tryCatch()
function. If the error handler receives your message to exit gracefully, then it just ignores the error and set the continuation flag to FALSE
.
matplotlib: plot multiple columns of pandas data frame on the bar chart
You can plot several columns at once by supplying a list of column names to the plot
's y
argument.
df.plot(x="X", y=["A", "B", "C"], kind="bar")
This will produce a graph where bars are sitting next to each other.
In order to have them overlapping, you would need to call plot
several times, and supplying the axes to plot to as an argument ax
to the plot.
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
y = np.random.rand(10,4)
y[:,0]= np.arange(10)
df = pd.DataFrame(y, columns=["X", "A", "B", "C"])
ax = df.plot(x="X", y="A", kind="bar")
df.plot(x="X", y="B", kind="bar", ax=ax, color="C2")
df.plot(x="X", y="C", kind="bar", ax=ax, color="C3")
plt.show()