Programs & Examples On #Intellij idea

IntelliJ IDEA is an IDE by JetBrains. It primarily supports Java development, but also supports JavaScript, Groovy, HTML, CSS, RSS, R, Haskell, PHP, Ruby, Python, Scala, Swift, Clojure, Kotlin, Hybris, Gradle and others. Questions specifically concerning usage and problems in both Community and Ultimate Editions should use this tag. However, if you have a problem with something else and just happen to be using IntelliJ, please don't use this tag.

Keyboard shortcut for Jump to Previous View Location (Navigate back/forward) in IntelliJ IDEA

Alt + Shift + ? (Left Arrow)

or

Ctrl + E (Recent Files pop-up).

Also check:

Ctrl + Shift + E (the Recently Edited Files pop-up).

Mac users, replace Ctrl with ? (command) and Alt with ? (option).

Update In v12.0 it's Alt + Shift +? (Left Arrow) instead of Alt + Ctrl + ? (Left Arrow).

Update 2 In v14.1 (and possibly earlier) it's Ctrl + [

Update 3 In IntelliJ IDEA 2016.3 it's Ctrl + Alt + ? (Left Arrow)

Update 4 In IntelliJ IDEA 2018.3 it's Alt + Shift + ? (Left Arrow)

Update 5 In IntelliJ IDEA 2019.3 it's Ctrl + Alt + ? (Left Arrow)

Class JavaLaunchHelper is implemented in two places

You can find all the details here:

  • IDEA-170117 "objc: Class JavaLaunchHelper is implemented in both ..." warning in Run consoles

It's the old bug in Java on Mac that got triggered by the Java Agent being used by the IDE when starting the app. This message is harmless and is safe to ignore. Oracle developer's comment:

The message is benign, there is no negative impact from this problem since both copies of that class are identical (compiled from the exact same source). It is purely a cosmetic issue.

The problem is fixed in Java 9 and in Java 8 update 152.

If it annoys you or affects your apps in any way (it shouldn't), the workaround for IntelliJ IDEA is to disable idea_rt launcher agent by adding idea.no.launcher=true into idea.properties (Help | Edit Custom Properties...). The workaround will take effect on the next restart of the IDE.

I don't recommend disabling IntelliJ IDEA launcher agent, though. It's used for such features as graceful shutdown (Exit button), thread dumps, workarounds a problem with too long command line exceeding OS limits, etc. Losing these features just for the sake of hiding the harmless message is probably not worth it, but it's up to you.

Setting up and using environment variables in IntelliJ Idea

It is possible to reference an intellij 'Path Variable' in an intellij 'Run Configuration'.

In 'Path Variables' create a variable for example ANALYTICS_VERSION.

In a 'Run Configuration' under 'Environment Variables' add for example the following:

ANALYTICS_LOAD_LOCATION=$MAVEN_REPOSITORY$\com\my\company\analytics\$ANALYTICS_VERSION$\bin

To answer the original question you would need to add an APP_HOME environment variable to your run configuration which references the path variable:

APP_HOME=$APP_HOME$

How to set IntelliJ IDEA Project SDK

For a new project select the home directory of the jdk

eg C:\Java\jdk1.7.0_99 or C:\Program Files\Java\jdk1.7.0_99

For an existing project.

1) You need to have a jdk installed on the system.

for instance in

C:\Java\jdk1.7.0_99

2) go to project structure under File menu ctrl+alt+shift+S

3) SDKs is located under Platform Settings. Select it.

4) click the green + up the top of the window.

5) select JDK (I have to use keyboard to select it do not know why).

select the home directory for your jdk installation.

should be good to go.

Package doesn't exist error in intelliJ

If you do not want to destroy .idea, you can try :

  • open Project Structure > Modules
  • unmark the java folder as a source folder
  • apply / rebuild
  • then mark it again as a source folder
  • rebuild

unable to remove file that really exists - fatal: pathspec ... did not match any files

I know this is not the OP's problem, but I ran into the same error with an entirely different basis, so I just wanted to drop it here in case anyone else has the same. This is Windows-specific, and I assume does not affect Linux users.

I had a LibreOffice doc file, call it final report.odt. I later changed its case to Final Report.odt. In Windows, this doesn't even count as a rename. final report.odt, Final Report.odt, FiNaL RePoRt.oDt are all the same. In Linux, these are all distinct.

When I eventually went to git rm "Final Report.odt" and got the "pathspec did not match any files" error. Only when I use the original casing at the time the file was added -- git rm "final report.odt" -- did it work.

Lesson learned: to change the case I should have instead done:

git mv "final report.odt" temp.odt
git mv temp.odt "Final Report.odt"

Again, that wasn't the problem for the OP here; and wouldn't affect a Linux user, as his posts shows he clearly is. I'm just including it for others who may have this problem in Windows git and stumble onto this question.

Use IntelliJ to generate class diagram

Try Ctrl+Alt+U

Also check if the UML plugin is activated (settings -> plugin, settings can be opened by Ctrl+Alt+S

How enable auto-format code for Intellij IDEA?

None of the solutions in Intellij is as elegant (or useful) as in Eclipse. What we need is feature request to the intellij so that we can add a hook (what actions to perform) when the IDE autosaves.

In Eclipse we can add "post-save" actions, such as organize imports and format the class. Yes you have to do a "save" or ctrl-s but the hook is very convenient.

How to create a .jar file or export JAR in IntelliJ IDEA (like Eclipse Java archive export)?

You didn't specify your IDEA version. Before 9.0 use Build | Build Jars, in IDEA 9.0 use Project Structure | Artifacts.

How to configure custom PYTHONPATH with VM and PyCharm?

In my experience, using a PYTHONPATH variable at all is usually the wrong approach, because it does not play nicely with VENV on windows. PYTHON on loading will prepare the path by prepending PYTHONPATH to the path, which can result in your carefully prepared Venv preferentially fetching global site packages.

Instead of using PYTHON path, include a pythonpath.pth file in the relevant site-packages directory (although beware custom pythons occasionally look for them in different locations, e.g. enthought looks in the same directory as python.exe for its .pth files) with each virtual environment. This will act like a PYTHONPATH only it will be specific to the python installation, so you can have a separate one for each python installation/environment. Pycharm integrates strongly with VENV if you just go to yse the VENV's python as your python installation.

See e.g. this SO question for more details on .pth files....

How do I create a new class in IntelliJ without using the mouse?

With Esc and Command + 1 you can navigate between project view and editor area - back and forward, in this way you can select the folder/location you need

With Control +Option + N you can trigger New file menu and select whatever you need, class, interface, file, etc. This works in editor as well in project view and it relates to the current selected location

// please consider that this is working with standard key mapping

How do you synchronise projects to GitHub with Android Studio?

For Android Studio 0.8.9: VCS --> Import into version contraol --> Share project on Github. It doesn't give you option to share in a specific repository or at least I couldn't find (my limitation!).

You can add your github info here: File --> Settings --> Version COntraol --> Github.

IntelliJ cannot find any declarations

For what its worth, in Pycharm it is: Right click on the root folder->Mark Directory as-> Sources Root

Re-run Spring Boot Configuration Annotation Processor to update generated metadata

Having included a dependency on spring-boot-configuration-processor in build.gradle:

annotationProcessor "org.springframework.boot:spring-boot-configuration-processor:2.4.1"

the only thing that worked for me, besides invalidating caches of IntelliJ and restarting, is

  1. Refresh button in side panel Reload All Gradle Projects
  2. Gradle task Clean
  3. Gradle task Build

Gradle - Could not target platform: 'Java SE 8' using tool chain: 'JDK 7 (1.7)'

Since I had to compile some source with 7 compatibility, because of some legacy system and ran into the same problem. I found out that in the gradle configuration there where two options set to java 8

sourceCompatibility = 1.8
targetCompatibility = 1.8

switching these to 1.7 solved the problem for me, keeping JAVA_HOME pointing to the installed JDK-7

sourceCompatibility = 1.7
targetCompatibility = 1.7

Configuring IntelliJ IDEA for unit testing with JUnit

One way of doing this is to do add junit.jar to your $CLASSPATH as an external dependency.

adding junit intellij

So to do that, go to project structure, and then add JUnit as one of the libraries as shown in the gif.

In the 'Choose Modules' prompt choose only the modules that you'd need JUnit for.

IntelliJ IDEA generating serialVersionUID

Install the GenerateSerialVersionUID plugin by Olivier Descout.

Go to: menu File ? Settings ? Plugins ? Browse repositories ? GenerateSerialVersionUID

Install the plugin and restart.

Now you can generate the id from menu Code ? Generate ? serialVersionUID` or the shortcut.

How to set JVM parameters for Junit Unit Tests?

Parameters can be set on the fly also.

mvn test -DargLine="-Dsystem.test.property=test"

See http://www.cowtowncoder.com/blog/archives/2010/04/entry_385.html

Maven plugins can not be found in IntelliJ

SOLVED !!!

This is how I fixed the issue...

  1. Tried one of the answers which include 'could solve it by enabling "use plugin registry" '. Did enable that but no luck.
  2. Tried again one of the answers in the thread which says 'If that does not work, Invalidate your caches (File > Invalidate caches) and restart.' Did that but again no luck.

  3. Tried These options .. Go to Settings --> Maven --> Importing and made sure the following was selected

    Import Maven projects automatically

    Create IDEA modules for aggregator projects Keep source...

    Exclude build dir...

    Use Maven output...

    Generated souces folders: "detect automatically"

    Phase to be...: "process-resources"

    Automatically download: "sources" & "documentation"

    Use Maven3 to import

    project VM options for importer: -Xmx512m

    But again no success.

    1. Now lets say I had 10 such plugins which didn't get resolve and among them the first was 'org.apache.maven.plugins:maven-site-plugin' I went to '.m2/repository/org/apache/maven/plugins/' and deleted the directory 'maven-site-plugin' and did a maven reimport again. Guess what, particular missing plugin got dowloaded. And I just followed similar steps for other missing plugins and all got resolved.

How to set editor theme in IntelliJ Idea

OK I found the problem, I was checking in the wrong place which is for the whole IDE's look and feel at File->Settings->Appearance

The correct place to change the editor appearance is through File->Settings->Editor->Colors &Fonts and then choose the scheme there. The imported settings appear there :)

Note: The theme site seems to have moved.

How to build jars from IntelliJ properly?

If you are working on spring/mvn project you can use this command:

mvn package -DskipTests

The jar file will be saved on target directoy.

Any way (or shortcut) to auto import the classes in IntelliJ IDEA like in Eclipse?

Seems like IntelliJ IDEA will import missed class automatically, and you can import them by hit Alt + Enter manually.

IntelliJ does not show 'Class' when we right click and select 'New'

Project Structure->Modules->{Your Module}->Sources->{Click the folder named java in src/main}->click the blue button which img is a blue folder,then you should see the right box contains new item(Source Folders).All be done;

IntelliJ IDEA 13 uses Java 1.5 despite setting to 1.7

[For IntelliJ IDEA 2016.2]

I would like to expand upon part of Peter Gromov's answer with an up-to-date screenshot. Specifically this particular part:

You might also want to take a look at Settings | Compiler | Java Compiler | Per-module bytecode version.

I believe that (at least in 2016.2): checking out different commits in git resets these to 1.5.

Per-module bytecode version

IntelliJ inspection gives "Cannot resolve symbol" but still compiles code

If all my pom.xml files are configured correctly and I still have issues with Maven in IntelliJ I do the following steps

  1. Read how to use maven in IntelliJ lately
  2. Make sure IntelliJ is configured to use Bundled Maven 3
  3. Find and TERMINATE actual java process that is executing Maven 3 repos indexing for IntelliJ(Termination can be done while IntelliJ is running). In case any problems with indices or dependencies not available(thought repositories were configured in pom.xml).
  4. Forced Update for all repositories in "IntelliJ / Settings / Build Tools / Maven / Repositories / ". Takes most of the time, disk space and bandwidth! Took me 20+ minutes to update index for Maven central repo.
  5. Hit Re-import all Maven project once again from IntelliJ
  6. It is a good practice to do steps 1-4 to leave IntelliJ and its demon java processes running over night, if you have multiple repositories and a complex project, so you have everything in sync for the next day. You can in theory use all popular indexed repos out there and launch index update for all repos at the same time(I suppose IntelliJ creates a queue and runs updates one after another) then it can take hours to complete(you will need to increase heap space for that too).

P.S. I've spent hours to understand(step 3) that IntelliJ's java demon process that handles maven index update was doing something wrong and I simply need to make IntelliJ to start it from scratch. Problem was solved without even restarting IntelliJ itself.

intellij incorrectly saying no beans of type found for autowired repository

My version of IntelliJ IDEA Ultimate (2016.3.4 Build 163) seems to support this. The trick is that you need to have enabled the Spring Data plugin.

enter image description here

How to install Intellij IDEA on Ubuntu?

You can also try my ubuntu repository: https://launchpad.net/~mmk2410/+archive/ubuntu/intellij-idea

To use it just run the following commands:

sudo apt-add-repository ppa:mmk2410/intellij-idea
sudo apt-get update

The community edition can then installed with

sudo apt-get install intellij-idea-community

and the ultimate edition with

sudo apt-get install intellij-idea-ultimate

Intellij Cannot resolve symbol on import

you can try invalidating the cache and restarting intellij, in many cases it will help.

File -> Invalidate Caches/Restart

How do I activate a Spring Boot profile when running from IntelliJ?

In my case I used below configuration at VM options in IntelliJ , it was not picking the local configurations but after a restart of IntelliJ it picked configuration details from IntelliJ and service started running.

-Dspring.profiles.active=local

Intellij IDEA Java classes not auto compiling on save

I had the same issue. I think it would be appropriate to check whether your class can be compiled or not. Click recompile (Ctrl+Shift+F9 by default). If its not working then you have to investigate why it isn't compiling.

In my case the code wasn't autocompiling because there were hidden errors with compilation (they weren't shown in logs anywhere and maven clean-install was working). The rootcause was incorrect Project Structure -> Modules configuration, so Intellij Idea wasn't able to build it according to this configuration.

How do I add a library (android-support-v7-appcompat) in IntelliJ IDEA

This is my solution, it is very similar to the previous one:

<dependency>
        <groupId>com.google.android</groupId>
        <artifactId>support-v7</artifactId>
        <scope>system</scope>
        <systemPath>${android.home}/support/v7/appcompat/libs/android-support-v7-appcompat.jar</systemPath>
        <version>19.0.1</version>
</dependency>

Where {android.home} is the root directory of the Android SDK and it uses systemPath instead of repository.

Error: Could not find or load main class in intelliJ IDE

enter image description here

modules.xml with wrong content, I don't know what's matter with my IDEA.

how to force maven to update local repo

If you are installing into local repository, there is no special index/cache update needed.

Make sure that:

  1. You have installed the first artifact in your local repository properly. Simply copying the file to .m2 may not work as expected. Make sure you install it by mvn install

  2. The dependency in 2nd project is setup correctly. Check on any typo in groupId/artifactId/version, or unmatched artifact type/classifier.

IntelliJ how to zoom in / out

Update: This answer is old. Intellij has since added actions to adjust font size. Check out Wilker's answer for assigning the new actions to keymaps.

Try Ctrl+Mouse Wheel which can be enabled under File > Settings... > Editor > General : Change font size (Zoom) with Ctrl+Mouse Wheel

git with IntelliJ IDEA: Could not read from remote repository

in pyCharm,

file|
    v-->settings|
                v-->Version Control|
                                   v-->Git

Here change SSH executable from Built-in into Native

then press apply and close

cannot resolve symbol javafx.application in IntelliJ Idea IDE

As indicated here, JavaFX is no longer included in openjdk.

So check, if you have <Java SDK root>/jre/lib/ext/jfxrt.jar on your classpath under Project Structure -> SDKs -> 1.x -> Classpath? If not, that could be why. Try adding it and see if that fixes your issue, e.g. on Ubuntu, install then openjfx package with sudo apt-get install openjfx.

Can't choose class as main class in IntelliJ

Here is the complete procedure for IDEA IntelliJ 2019.3:

  1. File > Project Structure

  2. Under Project Settings > Modules

  3. Under 'Sources' tab, right-click on 'src' folder and select 'Sources'.

  4. Apply changes.

Kotlin unresolved reference in IntelliJ

For me, it was due to the project missing Gradle Libraries in its project structure.

Just add in build.gradle: apply plugin: 'idea'

And then run: $ gradle idea

After that gradle rebuilds dependencies libraries and the references are recognized!

How do I set up IntelliJ IDEA for Android applications?

Once I have followed all these steps, I start to receive error messages in all android classes calls like:

Cannot resolve Android Classes

I revolved that including android.jar in the SDKs Platform Settings:

SKDs Classpath

Android Studio - Importing external Library/Jar

I had the problem not able to load jar file in libs folder in Android Studio. If you have added JAR file in libs folder, then just open build.gradle file and save it without editing anything else. If you have added this line

compile fileTree(dir: 'libs', include: ['*.jar'])

save it and clean the project .. In next build time Android Studio will load the JAR file.

Hope this helps.

What does the arrow operator, '->', do in Java?

That's part of the syntax of the new lambda expressions, to be introduced in Java 8. There are a couple of online tutorials to get the hang of it, here's a link to one. Basically, the -> separates the parameters (left-side) from the implementation (right side).

The general syntax for using lambda expressions is

(Parameters) -> { Body } where the -> separates parameters and lambda expression body.

The parameters are enclosed in parentheses which is the same way as for methods and the lambda expression body is a block of code enclosed in braces.

Error:java: javacTask: source release 8 requires target release 1.8

Many answers regarding Maven are right but you don't have to configure the plugin directly.

Like described on the wiki page of the Apache Maven Compiler Plugin you can just set the 2 properties used by the plugin.

<project>
  [...]
  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>
  [...]
</project>

Cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6

In my case, just changingTarget JVM Version like this: File > Setting > Kotlin Compiler > Target JVM Version > 1.8 did not help. However, it does resolved compile time error. But failed at runtime.

I also had to add following in app build.gradle file to make it work.

 android {
     // Other code here...
     kotlinOptions {
        jvmTarget = "1.8"
     }
 }

Best way to add Gradle support to IntelliJ Project

Add:

build.gradle 

in your root project folder, and use plugin for example:

apply plugin: 'idea'
//and standard one
apply plugin: 'java'

and with this fire from command line:

gradle cleanIdea 

and after that:

gradle idea

After that everything should work

How to configure "Shorten command line" method for whole project in IntelliJ

Inside your .idea folder, change workspace.xml file

Add

<property name="dynamic.classpath" value="true" />

to

  <component name="PropertiesComponent">
.
.
.
  </component>

Example

 <component name="PropertiesComponent">
    <property name="project.structure.last.edited" value="Project" />
    <property name="project.structure.proportion" value="0.0" />
    <property name="project.structure.side.proportion" value="0.0" />
    <property name="settings.editor.selected.configurable" value="preferences.pluginManager" />
    <property name="dynamic.classpath" value="true" />
  </component>

If you don't see one, feel free to add it yourself

 <component name="PropertiesComponent">
    <property name="dynamic.classpath" value="true" />
  </component>

How to define Gradle's home in IDEA?

This is where my gradle home is (Arch Linux):

/usr/share/java/gradle/

Error:java: invalid source release: 8 in Intellij. What does it mean?

I tried out all the steps mentioned in here https://stackoverflow.com/a/26009627/2058104, but the 4th point has now changed. You need to go to Preferences -> Build, Execution, Deployment -> Compiler -> Java Compiler

In there, as shown in below figure, you need to change the "Target bytecode version". Although, I changed it to 8 (since I needed to downgrade to Java 8), it was giving the same error, over and over. Therefore, try to remove the existing entry (in this table) and add it again. This worked for me.

enter image description here

On the other hand, clean the project and try to run again.

IntelliJ Organize Imports

Goto Help -> Find Action (Short Cut for this is Cntl + Shift + A) and type Optimize imports (Short cut for this is Cntl + Alt + O)

Intellij Idea: Importing Gradle project - getting JAVA_HOME not defined yet

Make sure you have a jdk setup. To do this, create a new project and then go to file -> project structure. From there you can add a new jdk. Once that is setup, go back to your gradle project and you should have a jdk to select in the 'Gradle JVM' field.

How can I create tests in Android Studio?

I think this post by Rex St John is very useful for unit testing with android studio.


(source: rexstjohn.com)

Unable to run Java code with Intellij IDEA

right click on the "SRC folder", select "Mark directory as:, select "Resource Root".

Then Edit the run configuration. select Run, run, edit configuration, with the plus button add an application configuration, give it a name (could be any name), and in the main class write down the full name of the main java class for example, com.example.java.MaxValues.

you might also need to check file, project structure, project settings-project, give it a folder for the compiler output, preferably a separate folder, under the java folder,

IntelliJ, can't start simple web application: Unable to ping server at localhost:1099

If you are using java 7 then make sure you have Tomcat 7

brew install tomcat@7

and update run configuration to Tomcat 7

Tomcat 9 is working with java 8

Getting "cannot find Symbol" in Java project in Intellij

If you are using Lombok, make sure you have enabled annotation processing.

How to add directory to classpath in an application run profile in IntelliJ IDEA?

You can try -Xbootclasspath/a:path option of java application launcher. By description it specifies "a colon-separated path of directires, JAR archives, and ZIP archives to append to the default bootstrap class path."

Setting up JUnit with IntelliJ IDEA

I needed to enable the JUnit plugin, after I linked my project with the jar files.

To enable the JUnit plugin, go to File->Settings, type "JUnit" in the search bar, and under "Plugins," check "JUnit.

vikingsteve's advice above will probably get the libraries linked right. Otherwise, open File->Project Structure, go to Libraries, hit the plus, and then browse to

C:\Program Files (x86)\JetBrains\IntelliJ IDEA Community Edition 14.1.1\lib\

and add these jar files:

hamcrest-core-1.3.jar
junit-4.11.jar 
junit.jar 

Getting Gradle dependencies in IntelliJ IDEA using Gradle build

Tried everything in this thread and nothing worked for me in IntelliJ 2020.2. This answer did the trick, but I had to set the correct path to the JDK and choose it in Gradle settings after that (as showed in figures bellow):

  1. Setting the correct path for the Java SDK (under File->Project Structure):

enter image description here

  1. In Gradle Window, click in "Gradle Settings..."

enter image description here

  1. Select the correct SDK from (1) here:

enter image description here

After that, the option "Reload All Gradle Projects" downloaded all dependencies as expected.

Cheers.

Unable to open debugger port in IntelliJ IDEA

Change debug port of your server configured in the Intelli J.

It will be fixed.enter image description here

How to remove unused imports in Intellij IDEA on commit?

Or you can do the following shortcut :

MAC : Shift + Command + A (Enter Action menu pops up)

And write : Optimize Imports

Package name does not correspond to the file path - IntelliJ

I had a similar error and in my case the fix was removing the '-' character from project name. Instead of my-app, I used MyApp

What are .iml files in Android Studio?

Add .idea and *.iml to .gitignore, you don't need those files to successfully import and compile the project.

IntelliJ show JavaDocs tooltip on mouse over

On my IntelliJ U on Mac I need to point with cursor on some method, variable etc. and press [cntrl] or [cmd] key. Then click on the link inside popup window which appeared to see JavaDocs

How do I rename the android package name?

Unfortunately all above didn't work for me. After having lots of trials, What worked for me in Android Studio:

  1. do a 'move' on the package to a new package name you want.(right click on package and select Refactor -> Move) If Refactor -> Move didn't work for you, then create a package with the name you want and move manually in the existing package to the new one, and then delete the old empty package.

  2. Change package name in manifest (manually)

  3. Have a replace for the old package name with the new package name globally (in the full path by going to Edit -> Find -> Replace In Path)

How to change the version of the 'default gradle wrapper' in IntelliJ IDEA?

The easiest way is to execute the following command from the command line (see Upgrading the Gradle Wrapper in documentation):

./gradlew wrapper --gradle-version 5.5

Moreover, you can use --distribution-type parameter with either bin or all value to choose a distribution type. Use all distribution type to avoid a hint from IntelliJ IDEA or Android Studio that will offer you to download Gradle with sources:

./gradlew wrapper --gradle-version 5.5 --distribution-type all

Or you can create a custom wrapper task

task wrapper(type: Wrapper) {
    gradleVersion = '5.5'
}

and run ./gradlew wrapper.

How to have the formatter wrap code with IntelliJ?

Or you can use the shortcut:

Ctrl + Alt + L

Getting "NoSuchMethodError: org.hamcrest.Matcher.describeMismatch" when running test in IntelliJ 10.5

The problem was that the wrong hamcrest.Matcher, not hamcrest.MatcherAssert, class was being used. That was being pulled in from a junit-4.8 dependency one of my dependencies was specifying.

To see what dependencies (and versions) are included from what source while testing, run:

mvn dependency:tree -Dscope=test

Force Intellij IDEA to reread all maven dependencies

Press Ctrl+Shift+A to find actions, and input "reimport", you will find the "Reimport All Maven Projects".

On a Mac, use ?+?+A instead.

Class file has wrong version 52.0, should be 50.0

In your IntelliJ idea find tools.jar replace it with tools.jar from yout JDK8

Error: JavaFX runtime components are missing, and are required to run this application with JDK 11

This worked for me:

File >> Project Structure >> Modules >> Dependency >> + (on left-side of window)

clicking the "+" sign will let you designate the directory where you have unpacked JavaFX's "lib" folder.

Scope is Compile (which is the default.) You can then edit this to call it JavaFX by double-clicking on the line.

then in:

Run >> Edit Configurations

Add this line to VM Options:

--module-path /path/to/JavaFX/lib --add-modules=javafx.controls

(oh and don't forget to set the SDK)

How to generate serial version UID in Intellij

IntelliJ IDEA Plugins / GenerateSerialVersionUID https://plugins.jetbrains.com/plugin/?idea&id=185

very nice, very easy to install. you can install that from plugins menu, select install from disk, select the jar file you unpacked in the lib folder. restart, control + ins, and it pops up to generate serial UID from menu. love it. :-)

Eclipse error: indirectly referenced from required .class files?

Since you give us very little details, most likely what you did, which is an incredibly easy mistake to make, is that instead of heading to

Build Path > Configure Build Path > Projects

and adding your additional project folder from there, instead you went to

Build Path > Configure Build Path > Libraries

and added your project folder from there instead.

This is most definitely the case if your code is all correct, but upon automatically reorganizing imports via the ctrl+space shortcut , instead of your import statements referring to com.your.additionalproject, your references all point to bin.com.your.additionalproject.

Note the bin. Meaning that you -are- indirectly referring to your class by treating your other project folder structure as a library, making your IDE doing all the wokr of finding the exactly binary class you're referring to.

To correct this, remove the folder from the Libraries, and instead add it under the Projects tab, and reorganize your imports. Your project should work fine.

IntelliJ can't recognize JavaFX 11 with OpenJDK 11

The issue that JavaFX is no longer part of JDK 11. The following solution works using IntelliJ (haven't tried it with NetBeans):

  1. Add JavaFX Global Library as a dependency:

    Settings -> Project Structure -> Module. In module go to the Dependencies tab, and click the add "+" sign -> Library -> Java-> choose JavaFX from the list and click Add Selected, then Apply settings.

  2. Right click source file (src) in your JavaFX project, and create a new module-info.java file. Inside the file write the following code :

    module YourProjectName { 
        requires javafx.fxml;
        requires javafx.controls;
        requires javafx.graphics;
        opens sample;
    }
    

    These 2 steps will solve all your issues with JavaFX, I assure you.

Reference : There's a You Tube tutorial made by The Learn Programming channel, will explain all the details above in just 5 minutes. I also recommend watching it to solve your problem: https://www.youtube.com/watch?v=WtOgoomDewo

Java "lambda expressions not supported at this language level"

For intellij 13, Simply change the Project language level itself to 8.0 with following navigation.

File
|
|
 ---------Project Structure -> Project tab
          |
          |________Project language level

java8

Module lang level

I also had to update Modules lang level when there was no maven plugin for java compiler.

File
|
|
 ---------Project Structure -> Modules tab
          |
          |________ language level

Modules lang level

But this Module lang level would automatically be fixed if there's already a maven plugin for it,

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.6.0</version>
        <configuration>
            <source>1.8</source>
            <target>1.8</target>
        </configuration>
    </plugin>

After changes everything looks good

Import Maven dependencies in IntelliJ IDEA

The problem appears to be that despite listing your dependencies in the pom.xml, IntelliJ IDEA does not rebuild those dependencies when you run your project.

What worked for me is this:

Go to 'Run' -> 'Edit Configurations...', find your application, make sure the "Before launch:" section is expanded, click the green plus sign, and select "Build Project".

enter image description here

Where to put the gradle.properties file

Actually there are 3 places where gradle.properties can be placed:

  1. Under gradle user home directory defined by the GRADLE_USER_HOME environment variable, which if not set defaults to USER_HOME/.gradle
  2. The sub-project directory (myProject2 in your case)
  3. 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.

How to display hidden characters by default (ZERO WIDTH SPACE ie. &#8203)

A very simple solution is to search your file(s) for non-ascii characters using a regular expression. This will nicely highlight all the spots where they are found with a border.

Search for [^\x00-\x7F] and check the box for Regex.

The result will look like this (in dark mode):

zero width space made visible

Android studio Error "Unsupported Modules Detected: Compilation is not supported for following modules"

I had the same issue on androidStudio 3.2 and clonning the project worked for me

How to view the list of compile errors in IntelliJ?

the "problem view" mentioned in previous answers was helpful, but i saw it didn't catch all the errors in project. After running application, it began populating other classes that had issues but didn't appear at first in that problems view.

How do you input command line arguments in IntelliJ IDEA?

Example I have a class Test:

Class Test

Then. Go to config to run class Test:

Step 1: Add Application

Add Application

Step 2:

Edit Configurations...

You can input arguments in the Program Arguments textbox.

Search all the occurrences of a string in the entire project in Android Studio

Use Ctrl + Shift + F combination for Windows and Linux to search everywhere, it shows preview also.

Use Ctrl + F combination for Windows and Linux to search in current file.

Use Shift + Shift (Double Tap Shift) combination for Windows and Linux to search Project File of Project.

Error: Unfortunately you can't have non-Gradle Java modules and > Android-Gradle modules in one project

This solution worked for me Android Studio 3.3.2.

  1. Delete the .iml file from the project directory.
  2. In android studio File->invalidate caches/restart.
  3. Clean and Rebuild project if the auto build throws error.

Maven home (M2_HOME) not being picked up by IntelliJ IDEA

If M2_HOME is configured to point to the Maven home directory then:

  1. Go to File -> Settings
  2. Search for Maven
  3. Select Runner
  4. Insert in the field VM Options the following string:

    Dmaven.multiModuleProjectDirectory=$M2_HOME
    

Click Apply and OK

Reset IntelliJ UI to Default

check, if this works for you.

File -> Settings -> (type appe in search box) and select Appearance -> Select Intellij from dropdown option of Theme on the right (under UI Options).

Hope this helps someone.

How to see JavaDoc in IntelliJ IDEA?

For me, it wasn't just getting the javadoc window to open, but also getting the complete javadoc to present. You may still get a sparse javadoc that is based solely on the method signature if you are importing libraries from a Maven repository and do not tell Idea to include the javadocs in the download. Be sure to tick the "JavaDocs" option in the "Download Library From Maven Repository" dialog, which can be found under Project Structure -> Projtect Settings -> Libraries.

How to set gradle home while importing existing project in Android studio

I am using Lubuntu, I ended up finding it in :

/usr/share/gradle

Git Stash vs Shelve in IntelliJ IDEA

When using JetBrains IDE's with Git, "stashing and unstashing actions are supported in addition to shelving and unshelving. These features have much in common; the major difference is in the way patches are generated and applied. Shelve can operate with either individual files or bunch of files, while Stash can only operate with a whole bunch of changed files at once. Here are some more details on the differences between them."

What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)

Press F4 at the project root and select the the root source pressing the source button. It resolved my problem!

for(; ;){
  makeGoodCode();
}

How to clear gradle cache?

To clear your gradle cache in android studio:

  1. open terminal and
  2. run gradlew clean

Where can I download IntelliJ IDEA Color Schemes?

Since it is hard to find good themes for IntelliJ IDEA, I've created this site: https://github.com/sdvoynikov/color-themes (note: site archived to GitHub repo) where there is a large collection of themes. There are 270 themes for now and the site is growing.

Screenshot of the site

P.S.: Help me and other people — do not forget to upvote when you download themes from this site!

What to gitignore from the .idea folder?

While maintaining the proper .gitignore file is helpful, I found this alternate approach is way cleaner and easier to use.

  • Create dummy folder my_project and inside that git clone my_real_project the actual project repo.
  • Now while opening the project in IDE (Intellij/Pycharm) open the folder my_project and mark my_project/my_real_project as the VCS root.
  • You can see my_project/.idea wouldn't pollute your git repo because it happily lives outside the git repo which is what you want. This way your .gitignore files stays clean as well.

This approach works better due to the below reasons.

1 - .gitignore file stays clean and we don't have to insert lines related to JetBrains products, that file is better used for binaries and libraries and autogen contents.

2 - Intellij keeps updating their projects and the files inside .idea keep changing every significant release from JB. What this means is we have to keep updating our .gitignore accordingly which is not an ideal use of time.

3 - Intellij has the flawed pattern here, most editors Atom, VS Code, Eclipse... nobody stores their IDE contents right inside project root. JB shouldn't be an exception either. It's the onus of Jetbrains to keep those files tracked outside project root. They have to refrain from polluting VCS root. This approach does just that. The .idea folder is kept outside the PROJECT_ROOT

Hope this helps.

Adding Jar files to IntellijIdea classpath

On the Mac version I was getting the error when trying to run JSON-Clojure.json.clj, which is the script to export a database table to JSON. To get it to work I had to download the latest Clojure JAR from http://clojure.org/ and then right-click on PHPStorm app in the Finder and "Show Package Contents". Then go to Contents in there. Then open the lib folder, and see a bunch of .jar files. Copy the clojure-1.8.0.jar file from the unzipped archive I downloaded from clojure.org into the aforementioned lib folder inside the PHPStorm.app/Contents/lib. Restart the app. Now it freaking works.

EDIT: You also have to put the JSR-223 script engine into PHPStorm.app/Contents/lib. It can be built from https://github.com/ato/clojure-jsr223 or downloaded from https://www.dropbox.com/s/jg7s0c41t5ceu7o/clojure-jsr223-1.5.1.jar?dl=0 .

What is the IntelliJ shortcut key to create a javadoc comment?

Shortcut Alt+Enter shows intention actions where you can choose "Add Javadoc".

"Default Activity Not Found" on Android Studio upgrade

In my case, there was a misstype in AndroidManifest.xml as shown below. Removing "o" letter above application tag solved. Apparently, Android Studio doesn't detect type errors in AndroidMainfest.xml

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

o
<application android:name=".AppName"
             android:allowBackup="false"
             android:icon="@drawable/ic_launcher"
             android:label="@string/app_name"
             android:theme="@android:style/Theme.Light.NoTitleBar">

intellij idea - Error: java: invalid source release 1.9

Alternatively via Project Settings:

  • Project Settings
  • Project
  • Project language Level (set to fit your needs)

Depending on how your build is set up, this may be the way to go.

Intellij idea cannot resolve anything in maven

If you imported your maven project in IntelliJ and there are errors because of maven imports not getting resolved, it maybe because of the custom maven settings.xml you may be using. I tried overriding it in the Intellij default maven settings but it did not help. Finally I had to keep it in ~/.m2/settings.xml and then IntelliJ finally honored it.

Removing Java 8 JDK from Mac

Use /usr/libexec/java_home ; I found these alias and function to be pretty useful in my ~/.profile:

alias java_ls='/usr/libexec/java_home -V 2>&1 | cut -s -d , -f 1 | cut -c 5-'
function java_use() {
    export JAVA_HOME=$(/usr/libexec/java_home -v $1)
    java -version
}

Why doesn't os.path.join() work in this case?

The latter strings shouldn't start with a slash. If they start with a slash, then they're considered an "absolute path" and everything before them is discarded.

Quoting the Python docs for os.path.join:

If a component is an absolute path, all previous components are thrown away and joining continues from the absolute path component.

Note on Windows, the behaviour in relation to drive letters, which seems to have changed compared to earlier Python versions:

On Windows, the drive letter is not reset when an absolute path component (e.g., r'\foo') is encountered. If a component contains a drive letter, all previous components are thrown away and the drive letter is reset. Note that since there is a current directory for each drive, os.path.join("c:", "foo") represents a path relative to the current directory on drive C: (c:foo), not c:\foo.

Is it possible to use an input value attribute as a CSS selector?

Following the currently top voted answer, I've found using a dataset / data attribute works well.

_x000D_
_x000D_
//Javascript

const input1 = document.querySelector("#input1");
input1.value = "0.00";
input1.dataset.value = input1.value;
//dataset.value will set "data-value" on the input1 HTML element
//and will be used by CSS targetting the dataset attribute

document.querySelectorAll("input").forEach((input) => {
  input.addEventListener("input", function() {
    this.dataset.value = this.value;
    console.log(this);
  })
})
_x000D_
/*CSS*/

input[data-value="0.00"] {
  color: red;
}
_x000D_
<!--HTML-->

<div>
  <p>Input1 is programmatically set by JavaScript:</p>
  <label for="input1">Input 1:</label>
  <input id="input1" value="undefined" data-value="undefined">
</div>
<br>
<div>
  <p>Try typing 0.00 inside input2:</p>
  <label for="input2">Input 2:</label>
  <input id="input2" value="undefined" data-value="undefined">
</div>
_x000D_
_x000D_
_x000D_

Saving an image in OpenCV

hopefully this will save images form your webcam

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <iostream>

using namespace std;
using namespace cv;

int main()
{
   VideoCapture cap(0);

   Mat save_img;

   cap >> save_img;

   char Esc = 0;

   while (Esc != 27 && cap.isOpened()) {        
    bool Frame = cap.read(save_img);        
    if (!Frame || save_img.empty()) {       
        cout << "error: frame not read from webcam\n";      
        break;                                              
    }
    namedWindow("save_img", CV_WINDOW_NORMAL);  
    imshow("imgOriginal", save_img);            
    Esc = waitKey(1);
}
imwrite("test.jpg",save_img); 
}

What are the undocumented features and limitations of the Windows FINDSTR command?

Preface
Much of the information in this answer has been gathered based on experiments run on a Vista machine. Unless explicitly stated otherwise, I have not confirmed whether the information applies to other Windows versions.

FINDSTR output
The documentation never bothers to explain the output of FINDSTR. It alludes to the fact that matching lines are printed, but nothing more.

The format of matching line output is as follows:

filename:lineNumber:lineOffset:text

where

fileName: = The name of the file containing the matching line. The file name is not printed if the request was explicitly for a single file, or if searching piped input or redirected input. When printed, the fileName will always include any path information provided. Additional path information will be added if the /S option is used. The printed path is always relative to the provided path, or relative to the current directory if none provided.

Note - The filename prefix can be avoided when searching multiple files by using the non-standard (and poorly documented) wildcards < and >. The exact rules for how these wildcards work can be found here. Finally, you can look at this example of how the non-standard wildcards work with FINDSTR.

lineNumber: = The line number of the matching line represented as a decimal value with 1 representing the 1st line of the input. Only printed if /N option is specified.

lineOffset: = The decimal byte offset of the start of the matching line, with 0 representing the 1st character of the 1st line. Only printed if /O option is specified. This is not the offset of the match within the line. It is the number of bytes from the beginning of the file to the beginning of the line.

text = The binary representation of the matching line, including any <CR> and/or <LF>. Nothing is left out of the binary output, such that this example that matches all lines will produce an exact binary copy of the original file.

FINDSTR "^" FILE >FILE_COPY

The /A option sets the color of the fileName:, lineNumber:, and lineOffset: output only. The text of the matching line is always output with the current console color. The /A option only has effect when output is displayed directly to the console. The /A option has no effect if the output is redirected to a file or piped. See the 2018-08-18 edit in Aacini's answer for a description of the buggy behavior when output is redirected to CON.

Most control characters and many extended ASCII characters display as dots on XP
FINDSTR on XP displays most non-printable control characters from matching lines as dots (periods) on the screen. The following control characters are exceptions; they display as themselves: 0x09 Tab, 0x0A LineFeed, 0x0B Vertical Tab, 0x0C Form Feed, 0x0D Carriage Return.

XP FINDSTR also converts a number of extended ASCII characters to dots as well. The extended ASCII characters that display as dots on XP are the same as those that are transformed when supplied on the command line. See the "Character limits for command line parameters - Extended ASCII transformation" section, later in this post

Control characters and extended ASCII are not converted to dots on XP if the output is piped, redirected to a file, or within a FOR IN() clause.

Vista and Windows 7 always display all characters as themselves, never as dots.

Return Codes (ERRORLEVEL)

  • 0 (success)
    • Match was found in at least one line of at least one file.
  • 1 (failure)
    • No match was found in any line of any file.
    • Invalid color specified by /A:xx option
  • 2 (error)
    • Incompatible options /L and /R both specified
    • Missing argument after /A:, /F:, /C:, /D:, or /G:
    • File specified by /F:file or /G:file not found
  • 255 (error)

Source of data to search (Updated based on tests with Windows 7)
Findstr can search data from only one of the following sources:

  • filenames specified as arguments and/or using the /F:file option.

  • stdin via redirection findstr "searchString" <file

  • data stream from a pipe type file | findstr "searchString"

Arguments/options take precedence over redirection, which takes precedence over piped data.

File name arguments and /F:file may be combined. Multiple file name arguments may be used. If multiple /F:file options are specified, then only the last one is used. Wild cards are allowed in filename arguments, but not within the file pointed to by /F:file.

Source of search strings (Updated based on tests with Windows 7)
The /G:file and /C:string options may be combined. Multiple /C:string options may be specified. If multiple /G:file options are specified, then only the last one is used. If either /G:file or /C:string is used, then all non-option arguments are assumed to be files to search. If neither /G:file nor /C:string is used, then the first non-option argument is treated as a space delimited list of search terms.

File names must not be quoted within the file when using the /F:FILE option.
File names may contain spaces and other special characters. Most commands require that such file names are quoted. But the FINDSTR /F:files.txt option requires that filenames within files.txt must NOT be quoted. The file will not be found if the name is quoted.

BUG - Short 8.3 filenames can break the /D and /S options
As with all Windows commands, FINDSTR will attempt to match both the long name and the short 8.3 name when looking for files to search. Assume the current folder contains the following non-empty files:

b1.txt
b.txt2
c.txt

The following command will successfully find all 3 files:

findstr /m "^" *.txt

b.txt2 matches because the corresponding short name B9F64~1.TXT matches. This is consistent with the behavior of all other Windows commands.

But a bug with the /D and /S options causes the following commands to only find b1.txt

findstr /m /d:. "^" *.txt
findstr /m /s "^" *.txt

The bug prevents b.txt2 from being found, as well as all file names that sort after b.txt2 within the same directory. Additional files that sort before, like a.txt, are found. Additional files that sort later, like d.txt, are missed once the bug has been triggered.

Each directory searched is treated independently. For example, the /S option would successfully begin searching in a child folder after failing to find files in the parent, but once the bug causes a short file name to be missed in the child, then all subsequent files in that child folder would also be missed.

The commands work bug free if the same file names are created on a machine that has NTFS 8.3 name generation disabled. Of course b.txt2 would not be found, but c.txt would be found properly.

Not all short names trigger the bug. All instances of bugged behavior I have seen involve an extension that is longer than 3 characters with a short 8.3 name that begins the same as a normal name that does not require an 8.3 name.

The bug has been confirmed on XP, Vista, and Windows 7.

Non-Printable characters and the /P option
The /P option causes FINDSTR to skip any file that contains any of the following decimal byte codes:
0-7, 14-25, 27-31.

Put another way, the /P option will only skip files that contain non-printable control characters. Control characters are codes less than or equal to 31 (0x1F). FINDSTR treats the following control characters as printable:

 8  0x08  backspace
 9  0x09  horizontal tab
10  0x0A  line feed
11  0x0B  vertical tab
12  0x0C  form feed
13  0x0D  carriage return
26  0x1A  substitute (end of text)

All other control characters are treated as non-printable, the presence of which causes the /P option to skip the file.

Piped and Redirected input may have <CR><LF> appended
If the input is piped in and the last character of the stream is not <LF>, then FINDSTR will automatically append <CR><LF> to the input. This has been confirmed on XP, Vista and Windows 7. (I used to think that the Windows pipe was responsible for modifying the input, but I have since discovered that FINDSTR is actually doing the modification.)

The same is true for redirected input on Vista. If the last character of a file used as redirected input is not <LF>, then FINDSTR will automatically append <CR><LF> to the input. However, XP and Windows 7 do not alter redirected input.

FINDSTR hangs on XP and Windows 7 if redirected input does not end with <LF>
This is a nasty "feature" on XP and Windows 7. If the last character of a file used as redirected input does not end with <LF>, then FINDSTR will hang indefinitely once it reaches the end of the redirected file.

Last line of Piped data may be ignored if it consists of a single character
If the input is piped in and the last line consists of a single character that is not followed by <LF>, then FINDSTR completely ignores the last line.

Example - The first command with a single character and no <LF> fails to match, but the second command with 2 characters works fine, as does the third command that has one character with terminating newline.

> set /p "=x" <nul | findstr "^"

> set /p "=xx" <nul | findstr "^"
xx

> echo x| findstr "^"
x

Reported by DosTips user Sponge Belly at new findstr bug. Confirmed on XP, Windows 7 and Windows 8. Haven't heard about Vista yet. (I no longer have Vista to test).

Option syntax
Option letters are not case sensitive, so /i and /I are equivalent.

Options can be prefixed with either / or - Options may be concatenated after a single / or -. However, the concatenated option list may contain at most one multicharacter option such as OFF or F:, and the multi-character option must be the last option in the list.

The following are all equivalent ways of expressing a case insensitive regex search for any line that contains both "hello" and "goodbye" in any order

  • /i /r /c:"hello.*goodbye" /c:"goodbye.*hello"

  • -i -r -c:"hello.*goodbye" /c:"goodbye.*hello"

  • /irc:"hello.*goodbye" /c:"goodbye.*hello"

Options may also be quoted. So /i, -i, "/i" and "-i" are all equivalent. Likewise, /c:string, "/c":string, "/c:"string and "/c:string" are all equivalent.

If a search string begins with a / or - literal, then the /C or /G option must be used. Thanks to Stephan for reporting this in a comment (since deleted).

Search String length limits
On Vista the maximum allowed length for a single search string is 511 bytes. If any search string exceeds 511 then the result is a FINDSTR: Search string too long. error with ERRORLEVEL 2.

When doing a regular expression search, the maximum search string length is 254. A regular expression with length between 255 and 511 will result in a FINDSTR: Out of memory error with ERRORLEVEL 2. A regular expression length >511 results in the FINDSTR: Search string too long. error.

On Windows XP the search string length is apparently shorter. Findstr error: "Search string too long": How to extract and match substring in "for" loop? The XP limit is 127 bytes for both literal and regex searches.

Line Length limits
Files specified as a command line argument or via the /F:FILE option have no known line length limit. Searches were successfully run against a 128MB file that did not contain a single <LF>.

Piped data and Redirected input is limited to 8191 bytes per line. This limit is a "feature" of FINDSTR. It is not inherent to pipes or redirection. FINDSTR using redirected stdin or piped input will never match any line that is >=8k bytes. Lines >= 8k generate an error message to stderr, but ERRORLEVEL is still 0 if the search string is found in at least one line of at least one file.

Default type of search: Literal vs Regular Expression
/C:"string" - The default is /L literal. Explicitly combining the /L option with /C:"string" certainly works but is redundant.

"string argument" - The default depends on the content of the very first search string. (Remember that <space> is used to delimit search strings.) If the first search string is a valid regular expression that contains at least one un-escaped meta-character, then all search strings are treated as regular expressions. Otherwise all search strings are treated as literals. For example, "51.4 200" will be treated as two regular expressions because the first string contains an un-escaped dot, whereas "200 51.4" will be treated as two literals because the first string does not contain any meta-characters.

/G:file - The default depends on the content of the first non-empty line in the file. If the first search string is a valid regular expression that contains at least one un-escaped meta-character, then all search strings are treated as regular expressions. Otherwise all search strings are treated as literals.

Recommendation - Always explicitly specify /L literal option or /R regular expression option when using "string argument" or /G:file.

BUG - Specifying multiple literal search strings can give unreliable results

The following simple FINDSTR example fails to find a match, even though it should.

echo ffffaaa|findstr /l "ffffaaa faffaffddd"

This bug has been confirmed on Windows Server 2003, Windows XP, Vista, and Windows 7.

Based on experiments, FINDSTR may fail if all of the following conditions are met:

  • The search is using multiple literal search strings
  • The search strings are of different lengths
  • A short search string has some amount of overlap with a longer search string
  • The search is case sensitive (no /I option)

In every failure I have seen, it is always one of the shorter search strings that fails.

For more info see Why doesn't this FINDSTR example with multiple literal search strings find a match?

Quotes and backslahses within command line arguments
Note - User MC ND's comments reflect the actual horrifically complicated rules for this section. There are 3 distinct parsing phases involved:

  • First cmd.exe may require some quotes to be escaped as ^" (really nothing to do with FINDSTR)
  • Next FINDSTR uses the pre 2008 MS C/C++ argument parser, which has special rules for " and \
  • After the argument parser finishes, FINDSTR additionally treats \ followed by an alpha-numeric character as literal, but \ followed by non-alpha-numeric character as an escape character

The remainder of this highlighted section is not 100% correct. It can serve as a guide for many situations, but the above rules are required for total understanding.

Escaping Quote within command line search strings
Quotes within command line search strings must be escaped with backslash like \". This is true for both literal and regex search strings. This information has been confirmed on XP, Vista, and Windows 7.

Note: The quote may also need to be escaped for the CMD.EXE parser, but this has nothing to do with FINDSTR. For example, to search for a single quote you could use:

FINDSTR \^" file && echo found || echo not found

Escaping Backslash within command line literal search strings
Backslash in a literal search string can normally be represented as \ or as \\. They are typically equivalent. (There may be unusual cases in Vista where the backslash must always be escaped, but I no longer have a Vista machine to test).

But there are some special cases:

When searching for consecutive backslashes, all but the last must be escaped. The last backslash may optionally be escaped.

  • \\ can be coded as \\\ or \\\\
  • \\\ can be coded as \\\\\ or \\\\\\

Searching for one or more backslashes before a quote is bizarre. Logic would suggest that the quote must be escaped, and each of the leading backslashes would need to be escaped, but this does not work! Instead, each of the leading backslashes must be double escaped, and the quote is escaped normally:

  • \" must be coded as \\\\\"
  • \\" must be coded as \\\\\\\\\"

As previously noted, one or more escaped quotes may also require escaping with ^ for the CMD parser

The info in this section has been confirmed on XP and Windows 7.

Escaping Backslash within command line regex search strings

  • Vista only: Backslash in a regex must be either double escaped like \\\\, or else single escaped within a character class set like [\\]

  • XP and Windows 7: Backslash in a regex can always be represented as [\\]. It can normally be represented as \\. But this never works if the backslash precedes an escaped quote.

    One or more backslashes before an escaped quote must either be double escaped, or else coded as [\\]

    • \" may be coded as \\\\\" or [\\]\"
    • \\" may be coded as \\\\\\\\\" or [\\][\\]\" or \\[\\]\"

Escaping Quote and Backslash within /G:FILE literal search strings
Standalone quotes and backslashes within a literal search string file specified by /G:file need not be escaped, but they can be.

" and \" are equivalent.

\ and \\ are equivalent.

If the intent is to find \\, then at least the leading backslash must be escaped. Both \\\ and \\\\ work.

If the intent is to find ", then at least the leading backslash must be escaped. Both \\" and \\\" work.

Escaping Quote and Backslash within /G:FILE regex search strings
This is the one case where the escape sequences work as expected based on the documentation. Quote is not a regex metacharacter, so it need not be escaped (but can be). Backslash is a regex metacharacter, so it must be escaped.

Character limits for command line parameters - Extended ASCII transformation
The null character (0x00) cannot appear in any string on the command line. Any other single byte character can appear in the string (0x01 - 0xFF). However, FINDSTR converts many extended ASCII characters it finds within command line parameters into other characters. This has a major impact in two ways:

  1. Many extended ASCII characters will not match themselves if used as a search string on the command line. This limitation is the same for literal and regex searches. If a search string must contain extended ASCII, then the /G:FILE option should be used instead.

  2. FINDSTR may fail to find a file if the name contains extended ASCII characters and the file name is specified on the command line. If a file to be searched contains extended ASCII in the name, then the /F:FILE option should be used instead.

Here is a complete list of extended ASCII character transformations that FINDSTR performs on command line strings. Each character is represented as the decimal byte code value. The first code represents the character as supplied on the command line, and the second code represents the character it is transformed into. Note - this list was compiled on a U.S machine. I do not know what impact other languages may have on this list.

158 treated as 080     199 treated as 221     226 treated as 071
169 treated as 170     200 treated as 043     227 treated as 112
176 treated as 221     201 treated as 043     228 treated as 083
177 treated as 221     202 treated as 045     229 treated as 115
178 treated as 221     203 treated as 045     231 treated as 116
179 treated as 221     204 treated as 221     232 treated as 070
180 treated as 221     205 treated as 045     233 treated as 084
181 treated as 221     206 treated as 043     234 treated as 079
182 treated as 221     207 treated as 045     235 treated as 100
183 treated as 043     208 treated as 045     236 treated as 056
184 treated as 043     209 treated as 045     237 treated as 102
185 treated as 221     210 treated as 045     238 treated as 101
186 treated as 221     211 treated as 043     239 treated as 110
187 treated as 043     212 treated as 043     240 treated as 061
188 treated as 043     213 treated as 043     242 treated as 061
189 treated as 043     214 treated as 043     243 treated as 061
190 treated as 043     215 treated as 043     244 treated as 040
191 treated as 043     216 treated as 043     245 treated as 041
192 treated as 043     217 treated as 043     247 treated as 126
193 treated as 045     218 treated as 043     249 treated as 250
194 treated as 045     219 treated as 221     251 treated as 118
195 treated as 043     220 treated as 095     252 treated as 110
196 treated as 045     222 treated as 221     254 treated as 221
197 treated as 043     223 treated as 095
198 treated as 221     224 treated as 097

Any character >0 not in the list above is treated as itself, including <CR> and <LF>. The easiest way to include odd characters like <CR> and <LF> is to get them into an environment variable and use delayed expansion within the command line argument.

Character limits for strings found in files specified by /G:FILE and /F:FILE options
The nul (0x00) character can appear in the file, but it functions like the C string terminator. Any characters after a nul character are treated as a different string as if they were on another line.

The <CR> and <LF> characters are treated as line terminators that terminate a string, and are not included in the string.

All other single byte characters are included perfectly within a string.

Searching Unicode files
FINDSTR cannot properly search most Unicode (UTF-16, UTF-16LE, UTF-16BE, UTF-32) because it cannot search for nul bytes and Unicode typically contains many nul bytes.

However, the TYPE command converts UTF-16LE with BOM to a single byte character set, so a command like the following will work with UTF-16LE with BOM.

type unicode.txt|findstr "search"

Note that Unicode code points that are not supported by your active code page will be converted to ? characters.

It is possible to search UTF-8 as long as your search string contains only ASCII. However, the console output of any multi-byte UTF-8 characters will not be correct. But if you redirect the output to a file, then the result will be correctly encoded UTF-8. Note that if the UTF-8 file contains a BOM, then the BOM will be considered as part of the first line, which could throw off a search that matches the beginning of a line.

It is possible to search multi-byte UTF-8 characters if you put your search string in a UTF-8 encoded search file (without BOM), and use the /G option.

End Of Line
FINDSTR breaks lines immediately after every <LF>. The presence or absence of <CR> has no impact on line breaks.

Searching across line breaks
As expected, the . regex metacharacter will not match <CR> or <LF>. But it is possible to search across a line break using a command line search string. Both the <CR> and <LF> characters must be matched explicitly. If a multi-line match is found, only the 1st line of the match is printed. FINDSTR then doubles back to the 2nd line in the source and begins the search all over again - sort of a "look ahead" type feature.

Assume TEXT.TXT has these contents (could be Unix or Windows style)

A
A
A
B
A
A

Then this script

@echo off
setlocal
::Define LF variable containing a linefeed (0x0A)
set LF=^


::Above 2 blank lines are critical - do not remove

::Define CR variable containing a carriage return (0x0D)
for /f %%a in ('copy /Z "%~dpf0" nul') do set "CR=%%a"

setlocal enableDelayedExpansion
::regex "!CR!*!LF!" will match both Unix and Windows style End-Of-Line
findstr /n /r /c:"A!CR!*!LF!A" TEST.TXT

gives these results

1:A
2:A
5:A

Searching across line breaks using the /G:FILE option is imprecise because the only way to match <CR> or <LF> is via a regex character class range expression that sandwiches the EOL characters.

  • [<TAB>-<0x0B>] matches <LF>, but it also matches <TAB> and <0x0B>

  • [<0x0C>-!] matches <CR>, but it also matches <0x0C> and !

Note - the above are symbolic representations of the regex byte stream since I can't graphically represent the characters.

Answer continued in part 2 below...

How to set the holo dark theme in a Android app?

By default android will set Holo to the Dark theme. There is no theme called Holo.Dark, there's only Holo.Light, that's why you are getting the resource not found error.

So just set it to:

<style name="AppTheme" parent="android:Theme.Holo" />

Check date with todays date

I assume you are using integers to represent your year, month, and day? If you want to remain consistent, use the Date methods.

Calendar cal = new Calendar();
int currentYear, currentMonth, currentDay; 
currentYear = cal.get(Calendar.YEAR); 
currentMonth = cal.get(Calendar.MONTH); 
currentDay = cal.get(Calendar.DAY_OF_WEEK);

     if(startYear < currentYear)
                {
                    message = message + "Start Date is Before Today" + "\n";
                }
            else if(startMonth < currentMonth && startYear <= currentYear)
                    {
                        message = message + "Start Date is Before Today" + "\n";
                    }
            else if(startDay < currentDay && startMonth <= currentMonth && startYear <= currentYear)
                        {
                            message = message + "Start Date is Before Today" + "\n";
                        }

What is Python used for?

Python is a dynamic, strongly typed, object oriented, multipurpose programming language, designed to be quick (to learn, to use, and to understand), and to enforce a clean and uniform syntax.

  1. Python is dynamically typed: it means that you don't declare a type (e.g. 'integer') for a variable name, and then assign something of that type (and only that type). Instead, you have variable names, and you bind them to entities whose type stays with the entity itself. a = 5 makes the variable name a to refer to the integer 5. Later, a = "hello" makes the variable name a to refer to a string containing "hello". Static typed languages would have you declare int a and then a = 5, but assigning a = "hello" would have been a compile time error. On one hand, this makes everything more unpredictable (you don't know what a refers to). On the other hand, it makes very easy to achieve some results a static typed languages makes very difficult.
  2. Python is strongly typed. It means that if a = "5" (the string whose value is '5') will remain a string, and never coerced to a number if the context requires so. Every type conversion in python must be done explicitly. This is different from, for example, Perl or Javascript, where you have weak typing, and can write things like "hello" + 5 to get "hello5".
  3. Python is object oriented, with class-based inheritance. Everything is an object (including classes, functions, modules, etc), in the sense that they can be passed around as arguments, have methods and attributes, and so on.
  4. Python is multipurpose: it is not specialised to a specific target of users (like R for statistics, or PHP for web programming). It is extended through modules and libraries, that hook very easily into the C programming language.
  5. Python enforces correct indentation of the code by making the indentation part of the syntax. There are no control braces in Python. Blocks of code are identified by the level of indentation. Although a big turn off for many programmers not used to this, it is precious as it gives a very uniform style and results in code that is visually pleasant to read.
  6. The code is compiled into byte code and then executed in a virtual machine. This means that precompiled code is portable between platforms.

Python can be used for any programming task, from GUI programming to web programming with everything else in between. It's quite efficient, as much of its activity is done at the C level. Python is just a layer on top of C. There are libraries for everything you can think of: game programming and openGL, GUI interfaces, web frameworks, semantic web, scientific computing...

XPath: difference between dot and text()

enter image description here The XPath text() function locates elements within a text node while dot (.) locate elements inside or outside a text node. In the image description screenshot, the XPath text() function will only locate Success in DOM Example 2. It will not find success in DOM Example 1 because it's located between the tags.

In addition, the text() function will not find success in DOM Example 3 because success does not have a direct relationship to the element . Here's a video demo explaining the difference between text() and dot (.) https://youtu.be/oi2Q7-0ZIBg

Pretty-print an entire Pandas Series / DataFrame

Using pd.options.display

This answer is a variation of the prior answer by lucidyan. It makes the code more readable by avoiding the use of set_option.

After importing pandas, as an alternative to using the context manager, set such options for displaying large dataframes:

def set_pandas_display_options() -> None:
    """Set pandas display options."""
    # Ref: https://stackoverflow.com/a/52432757/
    display = pd.options.display

    display.max_columns = 1000
    display.max_rows = 1000
    display.max_colwidth = 199
    display.width = None
    # display.precision = 2  # set as needed

set_pandas_display_options()

After this, you can use either display(df) or just df if using a notebook, otherwise print(df).

Using to_string

Pandas 0.25.3 does have DataFrame.to_string and Series.to_string methods which accept formatting options.

Using to_markdown

If what you need is markdown output, Pandas 1.0.0 has DataFrame.to_markdown and Series.to_markdown methods.

Using to_html

If what you need is HTML output, Pandas 0.25.3 does have a DataFrame.to_html method but not a Series.to_html. Note that a Series can be converted to a DataFrame.

How to solve this java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream?

just put all apache comons jar and file upload jar in lib folder of tomcat

What are static factory methods?

Java implementation contains utilities classes java.util.Arrays and java.util.Collections both of them contains static factory methods, examples of it and how to use :

Also java.lang.String class have such static factory methods:

  • String.format(...), String.valueOf(..), String.copyValueOf(...)

How do I set the colour of a label (coloured text) in Java?

object.setForeground(Color.green);

*any colour you wish *object being declared earlier

What's the best way to get the last element of an array without deleting it?

To get the last element of an array, use:

$lastElement = array_slice($array, -1)[0];

Benchmark

I iterated 1,000 times, grabbing the last element of small and large arrays that contained 100 and 50,000 elements, respectively.

Method: $array[count($array)-1];
Small array (s): 0.000319957733154
Large array (s): 0.000526905059814
Note: Fastest!  count() must access an internal length property.
Note: This method only works if the array is naturally-keyed (0, 1, 2, ...).

Method: array_slice($array, -1)[0];
Small array (s): 0.00145292282104
Large array (s): 0.499367952347

Method: array_pop((array_slice($array, -1, 1)));
Small array (s): 0.00162816047668
Large array (s): 0.513121843338

Method: end($array);
Small array (s): 0.0028350353241
Large array (s): 4.81077480316
Note: Slowest...

I used PHP Version 5.5.32.

Xcode 6 Storyboard the wrong size?

On your storyboard page, go to File Inspector and uncheck 'Use Size Classes'. This should shrink your view controller to regular IPhone size you were familiar with. Note that using 'size classes' will let you design your project across many devices. Once you uncheck this the Xcode will give you a warning dialogue as follows. This should be self-explainatory.

"Disabling size classes will limit this document to storing data for a single device family. The data for the size class best representing the targeted device will be retained, and all other data will be removed. In addition, segues will be converted to their non-adaptive equivalents."

Could not load file or assembly Exception from HRESULT: 0x80131040

I have issue with itextsharp and itextsharp.xmlworker dlls for exception-from-hresult-0x80131040 so I have removed those both dlls from references and downloaded new dlls directly from nuget packages, which resolved my issue.

May be this method can be useful to resolved the issue to other people.

set value of input field by php variable's value

inside the Form, You can use this code. Replace your variable name (i use $variable)

<input type="text" value="<?php echo (isset($variable))?$variable:'';?>">

How can I check whether a radio button is selected with JavaScript?

This is also working, avoiding to call for an element id but calling it using as an array element.

The following code is based on the fact that an array, named as the radiobuttons group, is composed by radiobuttons elements in the same order as they where declared in the html document:

if(!document.yourformname.yourradioname[0].checked 
   && !document.yourformname.yourradioname[1].checked){
    alert('is this working for all?');
    return false;
}

Count characters in textarea

Here my example. Supper simple

_x000D_
_x000D_
$(document).ready(function() {_x000D_
      _x000D_
        var textarea    = $("#my_textarea");_x000D_
  _x000D_
        textarea.keydown(function(event) {_x000D_
          _x000D_
            var numbOfchars = textarea.val();_x000D_
            var len = numbOfchars.length;_x000D_
            $(".chars-counter").text(len);_x000D_
_x000D_
        });_x000D_
  _x000D_
  _x000D_
 }); 
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<textarea id="my_textarea" class="uk-textarea" rows="5" name="text"></textarea>_x000D_
<h1 class="chars-counter">0</h1>
_x000D_
_x000D_
_x000D_

C# find highest array value and index

public static void Main()
{
    int a,b=0;
    int []arr={1, 2, 2, 3, 3, 4, 5, 6, 5, 7, 7, 7, 100, 8, 1};

    for(int i=arr.Length-1 ; i>-1 ; i--)
        {
            a = arr[i];

            if(a > b)
            {
                b=a;    
            }
        }
    Console.WriteLine(b);
}

- java.lang.NullPointerException - setText on null object reference

private void fillTextView (int id, String text) {
    TextView tv = (TextView) findViewById(id);
    tv.setText(text);
}

If this is where you're getting the null pointer exception, there was no view found for the id that you passed into findViewById(), and the actual exception is thrown when you try to call a function setText() on null. You should post your XML for R.layout.activity_main, as it's hard to tell where things went wrong just by looking at your code.

More reading on null pointers: What is a NullPointerException, and how do I fix it?

Avoid line break between html elements

CSS for that td: white-space: nowrap; should solve it.

Where to place the 'assets' folder in Android Studio?

Put the assets folder in the main/src/assets path.

Android: keep Service running when app is killed

inside onstart command put START_STICKY... This service won't kill unless it is doing too much task and kernel wants to kill it for it...

@Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            Log.i("LocalService", "Received start id " + startId + ": " + intent);
            // We want this service to continue running until it is explicitly
            // stopped, so return sticky.
            return START_STICKY;
        }

How does "cat << EOF" work in bash?

Long story short, EOF marker(but a different literal can be used as well) is a heredoc format that allows you to provide your input as multiline. A lot of confusion comes from how cat actually works it seems. You can use cat with >> or > as follows:

$ cat >> temp.txt
line 1
line 2

While cat can be used this way when writing manually into console, it's not convenient if I want to provide the input in a more declarative way so that it can be reused by tools and also to keep indentations, whitespaces, etc.
Heredoc allows to define your entire input as if you are not working with stdin but typing in a separate text editor. This is what Wikipedia article means by:

it is a section of a source code file that is treated as if it were a separate file.

How to check if text fields are empty on form submit using jQuery?

You can use 'required' http://jsbin.com/atefuq/1/edit

<form action="login.php" method="post">
    <label>Login Name:</label>
    <input required type="text" name="email" id="log" />
    <label>Password:</label>
    <input required type="password" name="password" id="pwd" />
    <input  required type="submit" name="submit" value="Login" />
</form>

How to change ProgressBar's progress indicator color in Android

simply add android:indeterminateTint="@color/colorPrimary" to your progressBar

Example:

<ProgressBar
    android:id="@+id/progressBar"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:indeterminateTint="@color/colorPrimary"/>

in case of progressBarStyleHorizontal change android:progressTint="@color/colorPrimary"

Example:

 <ProgressBar
    android:id="@+id/progressBar"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:progress="50"
    android:progressTint="@color/colorPrimary" />

How to use JavaScript variables in jQuery selectors?

var x = $(this).attr("name");
$("#" + x).hide();

Stashing only staged changes in git - is it possible?

With latest git you may use --patch option

git stash push --patch   # since 2.14.6

git stash save --patch   # for older git versions

And git will ask you for each change in your files to add or not into stash.
You just answer y or n

UPD
Alias for DOUBLE STASH:

git config --global alias.stash-staged '!bash -c "git stash --keep-index; git stash push -m "staged" --keep-index; git stash pop stash@{1}"'

Now you can stage your files and then run git stash-staged.
As result your staged files will be saved into stash.

If you do not want to keep staged files and want move them into stash. Then you can add another alias and run git move-staged:

git config --global alias.move-staged '!bash -c "git stash-staged;git commit -m "temp"; git stash; git reset --hard HEAD^; git stash pop"'

EC2 Instance Cloning

There is no explicit Clone button. Basically what you do is create an image, or snapshot of an existing EC2 instance, and then spin up a new instance using that snapshot.

First create an image from an existing EC2 instance.

enter image description here


Check your snapshots list to see if the process is completed. This usually takes around 20 minutes depending on how large your instance drive is.

enter image description here


Then, you need to create a new instance and use that image as the AMI.

enter image description here

enter image description here

What does [object Object] mean? (JavaScript)

If you are popping it in the DOM then try wrapping it in

<pre>
    <code>{JSON.stringify(REPLACE_WITH_OBJECT, null, 4)}</code>
</pre>

makes a little easier to visually parse.

Can't connect to docker from docker-compose

When you get an Error:

ERROR: Couldn't connect to Docker daemon at http+docker://localhost - is it running?

The Solution would be:

  1. First, try verifying Docker Service is Up and Running as expected on your remote/local machine:sudo service docker status

    if Not - run sudo service docker start or sudo systemctl start docker (depends on some linux versions, see Docker get started instructions).

  2. Second, start docker as sudo sudo docker-compose up

What is Mocking?

There are plenty of answers on SO and good posts on the web about mocking. One place that you might want to start looking is the post by Martin Fowler Mocks Aren't Stubs where he discusses a lot of the ideas of mocking.

In one paragraph - Mocking is one particlar technique to allow testing of a unit of code with out being reliant upon dependencies. In general, what differentiates mocking from other methods is that mock objects used to replace code dependencies will allow expectations to be set - a mock object will know how it is meant to be called by your code and how to respond.


Your original question mentioned TypeMock, so I've left my answer to that below:

TypeMock is the name of a commercial mocking framework.

It offers all the features of the free mocking frameworks like RhinoMocks and Moq, plus some more powerful options.

Whether or not you need TypeMock is highly debatable - you can do most mocking you would ever want with free mocking libraries, and many argue that the abilities offered by TypeMock will often lead you away from well encapsulated design.

As another answer stated 'TypeMocking' is not actually a defined concept, but could be taken to mean the type of mocking that TypeMock offers, using the CLR profiler to intercept .Net calls at runtime, giving much greater ability to fake objects (not requirements such as needing interfaces or virtual methods).

How to use SSH to run a local shell script on a remote machine?

If the script is short and is meant to be embedded inside your script and you are running under bash shell and also bash shell is available on the remote side, you may use declare to transfer local context to remote. Define variables and functions containing the state that will be transferred to the remote. Define a function that will be executed on the remote side. Then inside a here document read by bash -s you can use declare -p to transfer the variable values and use declare -f to transfer function definitions to the remote.

Because declare takes care of the quoting and will be parsed by the remote bash, the variables are properly quoted and functions are properly transferred. You may just write the script locally, usually I do one long function with the work I need to do on the remote side. The context has to be hand-picked, but the following method is "good enough" for any short scripts and is safe - should properly handle all corner cases.

somevar="spaces or other special characters"
somevar2="!@#$%^"
another_func() {
    mkdir -p "$1"
}
work() {
    another_func "$somevar"
    touch "$somevar"/"$somevar2"
}
ssh user@server 'bash -s' <<EOT
$(declare -p somevar somevar2)    # transfer variables values
$(declare -f work another_func)   # transfer function definitions
work                              # call the function
EOT

Equivalent to 'app.config' for a library (DLL)

I am currently creating plugins for a retail software brand, which are actually .net class libraries. As a requirement, each plugin needs to be configured using a config file. After a bit of research and testing, I compiled the following class. It does the job flawlessly. Note that I haven't implemented local exception handling in my case because, I catch exceptions at a higher level.

Some tweaking maybe needed to get the decimal point right, in case of decimals and doubles, but it works fine for my CultureInfo...

static class Settings
{
    static UriBuilder uri = new UriBuilder(Assembly.GetExecutingAssembly().CodeBase);
    static Configuration myDllConfig = ConfigurationManager.OpenExeConfiguration(uri.Path);
    static AppSettingsSection AppSettings = (AppSettingsSection)myDllConfig.GetSection("appSettings");
    static NumberFormatInfo nfi = new NumberFormatInfo() 
    { 
        NumberGroupSeparator = "", 
        CurrencyDecimalSeparator = "." 
    };

    public static T Setting<T>(string name)
    {
        return (T)Convert.ChangeType(AppSettings.Settings[name].Value, typeof(T), nfi);
    }
}

App.Config file sample

<add key="Enabled" value="true" />
<add key="ExportPath" value="c:\" />
<add key="Seconds" value="25" />
<add key="Ratio" value="0.14" />

Usage:

  somebooleanvar = Settings.Setting<bool>("Enabled");
  somestringlvar = Settings.Setting<string>("ExportPath");
  someintvar =     Settings.Setting<int>("Seconds");
  somedoublevar =  Settings.Setting<double>("Ratio");

Credits to Shadow Wizard & MattC

Scroll to a specific Element Using html

Yes you use this

<a href="#google"></a>

<div id="google"></div>

But this does not create a smooth scroll just so you know.

You can also add in your CSS

html {
  scroll-behavior: smooth;
}

How do I set the figure title and axes labels font size in Matplotlib?

If you're more used to using ax objects to do your plotting, you might find the ax.xaxis.label.set_size() easier to remember, or at least easier to find using tab in an ipython terminal. It seems to need a redraw operation after to see the effect. For example:

import matplotlib.pyplot as plt

# set up a plot with dummy data
fig, ax = plt.subplots()
x = [0, 1, 2]
y = [0, 3, 9]
ax.plot(x,y)

# title and labels, setting initial sizes
fig.suptitle('test title', fontsize=12)
ax.set_xlabel('xlabel', fontsize=10)
ax.set_ylabel('ylabel', fontsize='medium')   # relative to plt.rcParams['font.size']

# setting label sizes after creation
ax.xaxis.label.set_size(20)
plt.draw()

I don't know of a similar way to set the suptitle size after it's created.

Find closing HTML tag in Sublime Text

Under the "Goto" menu, Control + M is Jump to Matching Bracket. Works for parentheses as well.

How to solve COM Exception Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))?

The way that I resolved this issue was to register the COM via regsvr32.

ensure that the COM you are invoking is registered.

My application was using xceedcry.dll and I was not registering it. Once I registered it, the application worked fine.

How do I change Bootstrap 3's glyphicons to white?

You can just create your own .white class and add it to the glyphicon element.

.white, .white a {
  color: #fff;
}
<i class="glyphicon glyphicon-home white"></i>

Setting default values for columns in JPA

@Column(columnDefinition="tinyint(1) default 1")

I just tested the issue. It works just fine. Thanks for the hint.


About the comments:

@Column(name="price") 
private double price = 0.0;

This one doesn't set the default column value in the database (of course).

Convert absolute path into relative path given a current directory using Bash

Here is my version. It's based on the answer by @Offirmo. I made it Dash-compatible and fixed the following testcase failure:

./compute-relative.sh "/a/b/c/de/f/g" "/a/b/c/def/g/" --> "../..f/g/"

Now:

CT_FindRelativePath "/a/b/c/de/f/g" "/a/b/c/def/g/" --> "../../../def/g/"

See the code:

# both $1 and $2 are absolute paths beginning with /
# returns relative path to $2/$target from $1/$source
CT_FindRelativePath()
{
    local insource=$1
    local intarget=$2

    # Ensure both source and target end with /
    # This simplifies the inner loop.
    #echo "insource : \"$insource\""
    #echo "intarget : \"$intarget\""
    case "$insource" in
        */) ;;
        *) source="$insource"/ ;;
    esac

    case "$intarget" in
        */) ;;
        *) target="$intarget"/ ;;
    esac

    #echo "source : \"$source\""
    #echo "target : \"$target\""

    local common_part=$source # for now

    local result=""

    #echo "common_part is now : \"$common_part\""
    #echo "result is now      : \"$result\""
    #echo "target#common_part : \"${target#$common_part}\""
    while [ "${target#$common_part}" = "${target}" -a "${common_part}" != "//" ]; do
        # no match, means that candidate common part is not correct
        # go up one level (reduce common part)
        common_part=$(dirname "$common_part")/
        # and record that we went back
        if [ -z "${result}" ]; then
            result="../"
        else
            result="../$result"
        fi
        #echo "(w) common_part is now : \"$common_part\""
        #echo "(w) result is now      : \"$result\""
        #echo "(w) target#common_part : \"${target#$common_part}\""
    done

    #echo "(f) common_part is     : \"$common_part\""

    if [ "${common_part}" = "//" ]; then
        # special case for root (no common path)
        common_part="/"
    fi

    # since we now have identified the common part,
    # compute the non-common part
    forward_part="${target#$common_part}"
    #echo "forward_part = \"$forward_part\""

    if [ -n "${result}" -a -n "${forward_part}" ]; then
        #echo "(simple concat)"
        result="$result$forward_part"
    elif [ -n "${forward_part}" ]; then
        result="$forward_part"
    fi
    #echo "result = \"$result\""

    # if a / was added to target and result ends in / then remove it now.
    if [ "$intarget" != "$target" ]; then
        case "$result" in
            */) result=$(echo "$result" | awk '{ string=substr($0, 1, length($0)-1); print string; }' ) ;;
        esac
    fi

    echo $result

    return 0
}

Detect whether a Python string is a number or a letter

Check if string is positive digit (integer) and alphabet

You may use str.isdigit() and str.isalpha() to check whether given string is positive integer and alphabet respectively.

Sample Results:

# For alphabet
>>> 'A'.isdigit()
False
>>> 'A'.isalpha()
True

# For digit
>>> '1'.isdigit()
True
>>> '1'.isalpha()
False

Check for strings as positive/negative - integer/float

str.isdigit() returns False if the string is a negative number or a float number. For example:

# returns `False` for float
>>> '123.3'.isdigit()
False
# returns `False` for negative number
>>> '-123'.isdigit()
False

If you want to also check for the negative integers and float, then you may write a custom function to check for it as:

def is_number(n):
    try:
        float(n)   # Type-casting the string to `float`.
                   # If string is not a valid `float`, 
                   # it'll raise `ValueError` exception
    except ValueError:
        return False
    return True

Sample Run:

>>> is_number('123')    # positive integer number
True

>>> is_number('123.4')  # positive float number
True
 
>>> is_number('-123')   # negative integer number
True

>>> is_number('-123.4') # negative `float` number
True

>>> is_number('abc')    # `False` for "some random" string
False

Discard "NaN" (not a number) strings while checking for number

The above functions will return True for the "NAN" (Not a number) string because for Python it is valid float representing it is not a number. For example:

>>> is_number('NaN')
True

In order to check whether the number is "NaN", you may use math.isnan() as:

>>> import math
>>> nan_num = float('nan')

>>> math.isnan(nan_num)
True

Or if you don't want to import additional library to check this, then you may simply check it via comparing it with itself using ==. Python returns False when nan float is compared with itself. For example:

# `nan_num` variable is taken from above example
>>> nan_num == nan_num
False

Hence, above function is_number can be updated to return False for "NaN" as:

def is_number(n):
    is_number = True
    try:
        num = float(n)
        # check for "nan" floats
        is_number = num == num   # or use `math.isnan(num)`
    except ValueError:
        is_number = False
    return is_number

Sample Run:

>>> is_number('Nan')   # not a number "Nan" string
False

>>> is_number('nan')   # not a number string "nan" with all lower cased
False

>>> is_number('123')   # positive integer
True

>>> is_number('-123')  # negative integer
True

>>> is_number('-1.12') # negative `float`
True

>>> is_number('abc')   # "some random" string
False

Allow Complex Number like "1+2j" to be treated as valid number

The above function will still return you False for the complex numbers. If you want your is_number function to treat complex numbers as valid number, then you need to type cast your passed string to complex() instead of float(). Then your is_number function will look like:

def is_number(n):
    is_number = True
    try:
        #      v type-casting the number here as `complex`, instead of `float`
        num = complex(n)
        is_number = num == num
    except ValueError:
        is_number = False
    return is_number

Sample Run:

>>> is_number('1+2j')    # Valid 
True                     #      : complex number 

>>> is_number('1+ 2j')   # Invalid 
False                    #      : string with space in complex number represetantion
                         #        is treated as invalid complex number

>>> is_number('123')     # Valid
True                     #      : positive integer

>>> is_number('-123')    # Valid 
True                     #      : negative integer

>>> is_number('abc')     # Invalid 
False                    #      : some random string, not a valid number

>>> is_number('nan')     # Invalid
False                    #      : not a number "nan" string

PS: Each operation for each check depending on the type of number comes with additional overhead. Choose the version of is_number function which fits your requirement.

Word wrap for a label in Windows Forms

Have a better one based on @hypo 's answer

public class GrowLabel : Label {
    private bool mGrowing;
    public GrowLabel() {
        this.AutoSize = false;
    }
    private void resizeLabel() {
        if (mGrowing)
            return;
        try {
            mGrowing = true;
            int width = this.Parent == null ? this.Width : this.Parent.Width;

            Size sz = new Size(this.Width, Int32.MaxValue);
            sz = TextRenderer.MeasureText(this.Text, this.Font, sz, TextFormatFlags.WordBreak);
            this.Height = sz.Height + Padding.Bottom + Padding.Top;
        } finally {
            mGrowing = false;
        }
    }
    protected override void OnTextChanged(EventArgs e) {
        base.OnTextChanged(e);
        resizeLabel();
    }
    protected override void OnFontChanged(EventArgs e) {
        base.OnFontChanged(e);
        resizeLabel();
    }
    protected override void OnSizeChanged(EventArgs e) {
        base.OnSizeChanged(e);
        resizeLabel();
    }
}

int width = this.Parent == null ? this.Width : this.Parent.Width; this allows you to use auto-grow label when docked to a parent, e.g. a panel.

this.Height = sz.Height + Padding.Bottom + Padding.Top; here we take care of padding for top and bottom.

Python write line by line to a text file

Well, the problem you have is wrong line ending/encoding for notepad. Notepad uses Windows' line endings - \r\n and you use \n.

Java Long primitive type maximum limit

Exceding the maximum value of a long doesnt throw an exception, instead it cicles back. If you do this:

Long.MAX_VALUE + 1

you will notice that the result is the equivalent to Long.MIN_VALUE.

From here: java number exceeds long.max_value - how to detect?

Powershell script to locate specific file/file name?

I'm using this function based on @Murph answer. It searches inside the current directory and lists the full path:

function findit
{
$filename = $args[0];
gci -recurse -filter "*${filename}*" -file -ErrorAction SilentlyContinue | foreach-object {
    $place_path = $_.directory
    echo "${place_path}\${_}"
    }
}

Example usage: findit myfile

What does it mean when Statement.executeUpdate() returns -1?

I haven't seen this anywhere, either, but my instinct would be that this means that the IF prevented the whole statement from executing.

Try to run the statement with a database where the IF passes.

Also check if there are any triggers involved which might change the result.

[EDIT] When the standard says that this function should never return -1, that doesn't enforce this. Java doesn't have pre and post conditions. A JDBC driver could return a random number and there was no way to stop it.

If it's important to know why this happens, run the statement against different database until you have tried all execution paths (i.e. one where the IF returns false and one where it returns true).

If it's not that important, mark it off as a "clever trick" by a Microsoft engineer and remember how much you liked it when you feel like being clever yourself next time.

"Invalid form control" only in Google Chrome

No validate will do the job.

<form action="whatever" method="post" novalidate>

How to Convert date into MM/DD/YY format in C#

Have you tried the following?:

textbox1.text = System.DateTime.Today.ToString("MM/dd/yy");

Be aware that 2 digit years could be bad in the future...

What are the differences between Deferred, Promise and Future in JavaScript?

  • A promise represents a value that is not yet known
  • A deferred represents work that is not yet finished

A promise is a placeholder for a result which is initially unknown while a deferred represents the computation that results in the value.

Reference

Setting Windows PATH for Postgres tools

Set path For PostgreSQL in Windows:

  1. Searching for env will show Edit environment variables for your account
  2. Select Environment Variables
  3. From the System Variables box select PATH
  4. Click New (to add new path)

Change the PATH variable to include the bin directory of your PostgreSQL installation.
then add new path their....[for example]

C:\Program Files\PostgreSQL\12\bin

After that click OK

Open CMD/Command Prompt. Type this to open psql

psql -U username database_name

For Example psql -U postgres test

Now, you will be prompted to give Password for the User. (It will be hidden as a security measure).

Then you are good to go.

Visual Studio Code pylint: Unable to import 'protorpc'

I resolve this error by below step :

1 : first of all write this code in terminal :

...$ which python3
/usr/bin/python3

2 : Then :

"python.pythonPath": "/users/bin/python",

done.

Add MIME mapping in web.config for IIS Express

I was having a problem getting my ASP.NET 5.0/MVC 6 app to serve static binary file types or browse virtual directories. It looks like this is now done in Configure() at startup. See http://docs.asp.net/en/latest/fundamentals/static-files.html for a quick primer.

jQuery: Slide left and slide right

If you don't want something bloated like jQuery UI, try my custom animations: https://github.com/yckart/jquery-custom-animations

For you, blindLeftToggle and blindRightToggle is the appropriate choice.

http://jsfiddle.net/ARTsinn/65QsU/

Calculate difference between two dates (number of days)?

DateTime xmas = new DateTime(2009, 12, 25);
double daysUntilChristmas = xmas.Subtract(DateTime.Today).TotalDays;

Convert RGBA PNG to RGB with PIL

import numpy as np
import PIL

def convert_image(image_file):
    image = Image.open(image_file) # this could be a 4D array PNG (RGBA)
    original_width, original_height = image.size

    np_image = np.array(image)
    new_image = np.zeros((np_image.shape[0], np_image.shape[1], 3)) 
    # create 3D array

    for each_channel in range(3):
        new_image[:,:,each_channel] = np_image[:,:,each_channel]  
        # only copy first 3 channels.

    # flushing
    np_image = []
    return new_image

When to use margin vs padding in CSS

There are more technical explanations for your question, but if you want a way to think about margin and padding, this analogy might help.

Imagine block elements as picture frames hanging on a wall:

  • The photo is the content.
  • The matting is the padding.
  • The frame moulding is the border.
  • The wall is the viewport.
  • The space between two frames is the margin.

With this in mind, a good rule of thumb is to use margin when you want to space an element in relationship to other elements on the wall, and padding when you're adjusting the appearance of the element itself. Margin won't change the size of the element, but padding will make the element bigger1.


1 You can alter this behavior with the box-sizing attribute.

HTML meta tag for content language

As a complement to other answers note that you can also put the lang attribute on various HTML tags inside a page. For example to give a hint to the spellchecker that the input text should be in english:

<input ... spellcheck="true" lang="en"> ...

See: https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/lang

Using momentjs to convert date to epoch then back to date

There are a few things wrong here:

  • First, terminology. "Epoch" refers to the starting point of something. The "Unix Epoch" is Midnight, January 1st 1970 UTC. You can't convert an arbitrary "date string to epoch". You probably meant "Unix Time", which is often erroneously called "Epoch Time".

  • .unix() returns Unix Time in whole seconds, but the default moment constructor accepts a timestamp in milliseconds. You should instead use .valueOf() to return milliseconds. Note that calling .unix()*1000 would also work, but it would result in a loss of precision.

  • You're parsing a string without providing a format specifier. That isn't a good idea, as values like 1/2/2014 could be interpreted as either February 1st or as January 2nd, depending on the locale of where the code is running. (This is also why you get the deprecation warning in the console.) Instead, provide a format string that matches the expected input, such as:

    moment("10/15/2014 9:00", "M/D/YYYY H:mm")
    
  • .calendar() has a very specific use. If you are near to the date, it will return a value like "Today 9:00 AM". If that's not what you expected, you should use the .format() function instead. Again, you may want to pass a format specifier.

  • To answer your questions in comments, No - you don't need to call .local() or .utc().

Putting it all together:

var ts = moment("10/15/2014 9:00", "M/D/YYYY H:mm").valueOf();
var m = moment(ts);
var s = m.format("M/D/YYYY H:mm");
alert("Values are: ts = " + ts + ", s = " + s);

On my machine, in the US Pacific time zone, it results in:

Values are: ts = 1413388800000, s = 10/15/2014 9:00

Since the input value is interpreted in terms of local time, you will get a different value for ts if you are in a different time zone.

Also note that if you really do want to work with whole seconds (possibly losing precision), moment has methods for that as well. You would use .unix() to return the timestamp in whole seconds, and moment.unix(ts) to parse it back to a moment.

var ts = moment("10/15/2014 9:00", "M/D/YYYY H:mm").unix();
var m = moment.unix(ts);

How to get a key in a JavaScript object by its value?

With the Underscore.js library:

var hash = {
  foo: 1,
  bar: 2
};

(_.invert(hash))[1]; // => 'foo'

How do you give iframe 100% height

You can do it with CSS:

<iframe style="position: absolute; height: 100%; border: none"></iframe>

Be aware that this will by default place it in the upper-left corner of the page, but I guess that is what you want to achieve. You can position with the left,right, top and bottom CSS properties.

HTML input fields does not get focus when clicked

I had the similar issue - could not figure out what was the reason, but I fixed it using following code. Somehow it could not focus only the blank inputs:

$('input').click(function () {
        var val = $(this).val();
        if (val == "") {
            this.select();
        }
    });

PowerShell: Format-Table without headers

The -HideTableHeaders parameter unfortunately still causes the empty lines to be printed (and table headers appearently are still considered for column width). The only way I know that could reliably work here would be to format the output yourself:

| % { '{0,10} {1,20} {2,20}' -f $_.Operation,$_.AttributeName,$_.AttributeValue }

How to find all trigger associated with a table with SQL Server?

select so.name, text
from sysobjects so, syscomments sc
where type = 'TR'
and so.id = sc.id
and text like '%YourTableName%'

This way you can list out all the triggers associated with the given table.

Android studio Gradle icon error, Manifest Merger

When an attribute value contains a placeholder (see format below), the manifest merger will swap this placeholder value with an injected value. Injected values are specified in the build.gradle. The syntax for placeholder values is ${name} since @ is reserved for links. After the last file merging occurred, and before the resulting merged android manifest file is written out, all values with a placeholder will be swapped with injected values. A build breakage will be generated if a variable name is unknown.

from http://tools.android.com/tech-docs/new-build-system/user-guide/manifest-merger#TOC-Build-error

-XX:MaxPermSize with or without -XX:PermSize

-XX:PermSize specifies the initial size that will be allocated during startup of the JVM. If necessary, the JVM will allocate up to -XX:MaxPermSize.

Error importing SQL dump into MySQL: Unknown database / Can't create database

Open the sql file and comment out the line that tries to create the existing database.

Show ProgressDialog Android

Declare your progress dialog:

ProgressDialog progress;

When you're ready to start the progress dialog:

progress = ProgressDialog.show(this, "dialog title",
    "dialog message", true);

and to make it go away when you're done:

progress.dismiss();

Here's a little thread example for you:

// Note: declare ProgressDialog progress as a field in your class.

progress = ProgressDialog.show(this, "dialog title",
  "dialog message", true);

new Thread(new Runnable() {
  @Override
  public void run()
  {
    // do the thing that takes a long time

    runOnUiThread(new Runnable() {
      @Override
      public void run()
      {
        progress.dismiss();
      }
    });
  }
}).start();

You have to be inside an angular-cli project in order to use the build command after reinstall of angular-cli

I had the same error message. But the cause and solution are slightly different. When I ran "ng -v" it showed different versions for angular-cli (1.0.0-beta.28.3) and @angular/cli (1.0.0-beta.31). I re-ran:

npm install -g @angular/cli

Now both show a version of 1.0.0-beta.31. The error message is gone and "ng serve" now works. (Yes - it was @angular/cli that I re-installed and the angular-cli version was updated.)

Switch case: can I use a range instead of a one number

You could have switch construct "handle" ranges by using it in conjunction with a List of your bounds.

List<int> bounds = new List<int>() {int.MinValue, 0, 4, 9, 17, 20, int.MaxValue };

switch (bounds.IndexOf(bounds.Last(x => x < j)))
{
    case 0: // <=0
        break;

    case 1: // >= 1 and <=4
        break;
    case 2: // >= 5 and <=9
        break;
    case 3: // >= 10 and <=17
        break;
    case 4: // >= 18 and <=20
        break;

    case 5: // >20
        break;
}

With this approach ranges can have different spans.

Maven - Failed to execute goal org.apache.maven.plugins:maven-clean-plugin:2.4.1:clean

Failed to delete C:\EclipseProjects\myGoogleAppEngine\target\myGoogleAppEngine-0.0.1-SNAPSHOT\WEB-INF\lib\spring-webmvc-3.1.0.RELEASE.jar

Because of the path C:\EclipseProjects i guess you have eclipse running on that project. If you application runs, you cannot clean the output, because it may be in use.

Stop the application and maybe eclipse and try again.

Reading input files by line using read command in shell scripting skips last line

read reads until it finds a newline character or the end of file, and returns a non-zero exit code if it encounters an end-of-file. So it's quite possible for it to both read a line and return a non-zero exit code.

Consequently, the following code is not safe if the input might not be terminated by a newline:

while read LINE; do
  # do something with LINE
done

because the body of the while won't be executed on the last line.

Technically speaking, a file not terminated with a newline is not a text file, and text tools may fail in odd ways on such a file. However, I'm always reluctant to fall back on that explanation.

One way to solve the problem is to test if what was read is non-empty (-n):

while read -r LINE || [[ -n $LINE ]]; do
  # do something with LINE
done

Other solutions include using mapfile to read the file into an array, piping the file through some utility which is guaranteed to terminate the last line properly (grep ., for example, if you don't want to deal with blank lines), or doing the iterative processing with a tool like awk (which is usually my preference).

Note that -r is almost certainly needed in the read builtin; it causes read to not reinterpret \-sequences in the input.

Loading cross-domain endpoint with AJAX

Figured it out. Used this instead.

$('.div_class').load('http://en.wikipedia.org/wiki/Cross-origin_resource_sharing #toctitle');

iptables LOG and DROP in one rule

Example:

iptables -A INPUT -j LOG --log-prefix "INPUT:DROP:" --log-level 6
iptables -A INPUT -j DROP

Log Exampe:

Feb 19 14:18:06 servername kernel: INPUT:DROP:IN=eth1 OUT= MAC=aa:bb:cc:dd:ee:ff:11:22:33:44:55:66:77:88 SRC=x.x.x.x DST=x.x.x.x LEN=48 TOS=0x00 PREC=0x00 TTL=117 ID=x PROTO=TCP SPT=x DPT=x WINDOW=x RES=0x00 SYN URGP=0

Other options:

   LOG
       Turn on kernel logging of matching packets.  When this option 
       is set for a rule, the Linux kernel will print some 
       information  on  all  matching  packets
       (like most IP header fields) via the kernel log (where it can 
       be read with dmesg or syslogd(8)).  This is a "non-terminating 
       target", i.e. rule traversal
       continues at the next rule.  So if you want to LOG the packets 
       you refuse, use two separate rules with the same matching 
       criteria, first using target LOG
       then DROP (or REJECT).

       --log-level level
              Level of logging (numeric or see syslog.conf(5)).

       --log-prefix prefix
              Prefix log messages with the specified prefix; up to 29 
              letters long, and useful for distinguishing messages in 
              the logs.

       --log-tcp-sequence
              Log TCP sequence numbers. This is a security risk if the 
              log is readable by users.

       --log-tcp-options
              Log options from the TCP packet header.

       --log-ip-options
              Log options from the IP packet header.

       --log-uid
              Log the userid of the process which generated the packet.

Assign output of os.system to a variable and prevent it from being displayed on the screen

For python 3.5+ it is recommended that you use the run function from the subprocess module. This returns a CompletedProcess object, from which you can easily obtain the output as well as return code. Since you are only interested in the output, you can write a utility wrapper like this.

from subprocess import PIPE, run

def out(command):
    result = run(command, stdout=PIPE, stderr=PIPE, universal_newlines=True, shell=True)
    return result.stdout

my_output = out("echo hello world")
# Or
my_output = out(["echo", "hello world"])

Ruby class instance variable vs. class variable

I believe the main (only?) different is inheritance:

class T < S
end

p T.k
=> 23

S.k = 24
p T.k
=> 24

p T.s
=> nil

Class variables are shared by all "class instances" (i.e. subclasses), whereas class instance variables are specific to only that class. But if you never intend to extend your class, the difference is purely academic.

align images side by side in html

Here is how I would do it, (however I would use an external style sheet for this project and all others. just makes things easier to work with. Also this example is with html5.

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
  .container {
      display:inline-block;
  }
</style>
</head>
<body>

  <div class="container">
    <figure>
    <img src="http://placehold.it/350x150" height="200" width="200">
    <figcaption>This is image 1</figcaption>
    </figure>

    <figure>
    <img class="middle-img" src="http://placehold.it/350x150"/ height="200" width="200">
    <figcaption>This is image 2</figcaption>
    </figure>

    <figure>
    <img src="http://placehold.it/350x150" height="200" width="200">
    <figcaption>This is image 3</figcaption>
    </figure>

  </div>
</body>
</html>

How to serve all existing static files directly with NGINX, but proxy the rest to a backend server.

Try this:

location / {
    root /path/to/root;
    expires 30d;
    access_log off;
}

location ~* ^.*\.php$ {
    if (!-f $request_filename) {
        return 404;
    }
    proxy_set_header X-Real-IP  $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_pass http://127.0.0.1:8080;
}

Hopefully it works. Regular expressions have higher priority than plain strings, so all requests ending in .php should be forwared to Apache if only a corresponding .php file exists. Rest will be handled as static files. The actual algorithm of evaluating location is here.

Number of days between two dates in Joda-Time

Days Class

Using the Days class with the withTimeAtStartOfDay method should work:

Days.daysBetween(start.withTimeAtStartOfDay() , end.withTimeAtStartOfDay() ).getDays() 

Is there a keyboard shortcut (hotkey) to open Terminal in macOS?

I tested the following procedure under macOS Mojave 10.14.6 (18G3020).

Launch Automator. Create a document of type “Quick Action”:

quick action template

(In older versions of macOS, use the “Service” template.)

In the new Automator document, add a “Run AppleScript” action. (You can type “run applescript” into the search field at the top of the action list to find it.) Here's the AppleScript to paste into the action:

on run {input, parameters}
    tell application "Terminal"
        if it is running then
            do script ""
        end if
        activate
    end tell
end run

Set the “Workflow receives” popup to “no input”. It should look like this overall:

workflow with applescript

Save the document with the name “New Terminal”. Then go to the Automator menu (or the app menu in any running application) and open the Services submenu. You should now see the “New Terminal” quick action:

New Terminal service menu item

If you click the “New Terminal” menu item, you'll get a dialog box:

permission dialog

Click OK to allow the action to run. You'll see this dialog once in each application that's frontmost when you use the action. In other words, the first time you use the action while Finder is frontmost, you'll see the dialog. And the first time you use the action while Safari is frontmost, you'll see the dialog. And so on.

After you click OK in the dialog, Terminal should open a new window.

To assign a keyboard shortcut to the quick action, choose the “Services Preferences…” item from the Services menu. (Or launch System Preferences, choose the Keyboard pane, then choose the Shortcuts tab, then choose Services from the left-hand list.) Scroll to the bottom of the right-hand list and find the New Terminal service. Click it and you should see an “Add Shortcut” button:

add shortcut button

Click the button and press your preferred keyboard shortcut. Then, scratch your head, because (when I tried it) the Add Shortcut button reappears. But click the button again and you should see your shortcut:

keyboard shortcut set

Now you should be able to press your keyboard shortcut in most circumstances to get a new terminal window.

how to refresh my datagridview after I add new data

reload the form

Form1_Load(sender, e)

mysql SELECT IF statement with OR

IF(compliment IN('set','Y',1), 'Y', 'N') AS customer_compliment

Will do the job as Buttle Butkus suggested.

Map vs Object in JavaScript

I came across this post by Minko Gechev which clearly explains the major differences.

enter image description here

HTML.HiddenFor value set

For setting value in hidden field do in the following way:

@Html.HiddenFor(model => model.title, 
                new { id= "natureOfVisitField", Value = @Model.title})

It will work

How to use FormData for AJAX file upload?

Good morning.

I was have the same problem with upload of multiple images. Solution was more simple than I had imagined: include [] in the name field.

<input type="file" name="files[]" multiple>

I did not make any modification on FormData.

How create a new deep copy (clone) of a List<T>?

I'm disappointed Microsoft didn't offer a neat, fast and easy solution like Ruby are doing with the clone() method.

Except that does not create a deep copy, it creates a shallow copy.

With deep copying, you have to be always careful, what exactly do you want to copy. Some examples of possible issues are:

  1. Cycle in the object graph. For example, Book has an Author and Author has a list of his Books.
  2. Reference to some external object. For example, an object could contain open Stream that writes to a file.
  3. Events. If an object contains an event, pretty much anyone could be subscribed to it. This can get especially problematic if the subscriber is something like a GUI Window.

Now, there are basically two ways how to clone something:

  1. Implement a Clone() method in each class that you need cloned. (There is also ICloneable interface, but you should not use that; using a custom ICloneable<T> interface as Trevor suggested is okay.) If you know that all you need is to create a shallow copy of each field of this class, you could use MemberwiseClone() to implement it. As an alternative, you could create a “copy constructor”: public Book(Book original).
  2. Use serialization to serialize your objects into a MemoryStream and then deserialize them back. This requires you to mark each class as [Serializable] and it can also be configured what exactly (and how) should be serialized. But this is more of a “quick and dirty” solution, and will most likely also be less performant.

Rails: How can I rename a database column in a Ruby on Rails migration?

If the present data is not important for you, you can just take down your original migration using:

rake db:migrate:down VERSION='YOUR MIGRATION FILE VERSION HERE'

Without the quotes, then make changes in the original migration and run the up migration again by:

rake db:migrate

Pretty printing XML with javascript

XMLSpectrum formats XML, supports attribute indentation and also does syntax-highlighting for XML and any embedded XPath expressions:

XMLSpectrum formatted XML

XMLSpectrum is an open source project, coded in XSLT 2.0 - so you can run this server-side with a processor such as Saxon-HE (recommended) or client-side using Saxon-CE.

XMLSpectrum is not yet optimised to run in the browser - hence the recommendation to run this server-side.

git index.lock File exists when I try to commit, but cannot delete the file

On Linux, Unix, Git Bash, or Cygwin, try:

rm -f .git/index.lock

On Windows Command Prompt, try:

del .git\index.lock


For Windows:

  • From a PowerShell console opened as administrator, try

    rm -Force ./.git/index.lock
    
  • If that does not work, you must kill all git.exe processes

    taskkill /F /IM git.exe
    

    SUCCESS: The process "git.exe" with PID 20448 has been terminated.
    SUCCESS: The process "git.exe" with PID 11312 has been terminated.
    SUCCESS: The process "git.exe" with PID 23868 has been terminated.
    SUCCESS: The process "git.exe" with PID 27496 has been terminated.
    SUCCESS: The process "git.exe" with PID 33480 has been terminated.
    SUCCESS: The process "git.exe" with PID 28036 has been terminated. \

    rm -Force ./.git/index.lock
    

ArrayIndexOutOfBoundsException when using the ArrayList's iterator

Apart of larsmans answer (who is indeed correct), the exception in a call to a get() method, so the code you have posted is not the one that is causing the error.

Configuring user and password with Git Bash

If your repo is of HTTPS repo, git config -e give this command in the git bash. Update the username and password by opening in insert mode, change the password or username give :x and Cntrl+z keys it will save and exit

So, From then while you pull / push the code to the repository it will not ask for password.

Multiple radio button groups in MVC 4 Razor

I fixed a similar issue building a RadioButtonFor with pairs of text/value from a SelectList. I used a ViewBag to send the SelectList to the View, but you can use data from model too. My web application is a Blog and I have to build a RadioButton with some types of articles when he is writing a new post.

The code below was simplyfied.

List<SelectListItem> items = new List<SelectListItem>();

Dictionary<string, string> dictionary = new Dictionary<string, string>();

dictionary.Add("Texto", "1");
dictionary.Add("Foto", "2");
dictionary.Add("Vídeo", "3");

foreach (KeyValuePair<string, string> pair in objBLL.GetTiposPost())
{
    items.Add(new SelectListItem() { Text = pair.Key, Value = pair.Value, Selected = false });
}

ViewBag.TiposPost = new SelectList(items, "Value", "Text");

In the View, I used a foreach to build a radiobutton.

<div class="form-group">
    <div class="col-sm-10">
        @foreach (var item in (SelectList)ViewBag.TiposPost)
        {
            @Html.RadioButtonFor(model => model.IDTipoPost, item.Value, false)
            <label class="control-label">@item.Text</label>
        }

    </div>
</div>

Notice that I used RadioButtonFor in order to catch the option value selected by user, in the Controler, after submit the form. I also had to put the item.Text outside the RadioButtonFor in order to show the text options.

Hope it's useful!

How can I fix "Design editor is unavailable until a successful build" error?

None of the above worked for me. what worked for me is to go to File -> Invalidate Caches / Restart

Accessing inventory host variable in Ansible playbook

You are on the right track about hostvars.
This magic variable is used to access information about other hosts.

hostvars is a hash with inventory hostnames as keys.
To access fields of each host, use hostvars['test-1'], hostvars['test2-1'], etc.

ansible_ssh_host is deprecated in favor of ansible_host since 2.0.
So you should first remove "_ssh" from inventory hosts arguments (i.e. to become "ansible_user", "ansible_host", and "ansible_port"), then in your role call it with:

{{ hostvars['your_host_group'].ansible_host }}

What is the best way to conditionally apply attributes in AngularJS?

I actually wrote a patch to do this a few months ago (after someone asked about it in #angularjs on freenode).

It probably won't be merged, but it's very similar to ngClass: https://github.com/angular/angular.js/pull/4269

Whether it gets merged or not, the existing ng-attr-* stuff is probably suitable for your needs (as others have mentioned), although it might be a bit clunkier than the more ngClass-style functionality that you're suggesting.

How do you run CMD.exe under the Local System Account?

There is another way. There is a program called PowerRun which allows for elevated cmd to be run. Even with TrustedInstaller rights. It allows for both console and GUI commands.

How to make RatingBar to show five stars

To show a simple star rating in round figure just use this code

public static String getIntToStar(int starCount) {
        String fillStar = "\u2605";
        String blankStar = "\u2606";
        String star = "";

        for (int i = 0; i < starCount; i++) {
            star = star.concat(" " + fillStar);
        }
        for (int j = (5 - starCount); j > 0; j--) {
            star = star.concat(" " + blankStar);
        }
        return star;
    }

And use it like this

button.setText(getIntToStar(4));

SSIS Convert Between Unicode and Non-Unicode Error

I have been having the same issue and tried everything written here but it was still giving me the same error. Turned out to be NULL value in the column which I was trying to convert.

Removing the NULL value solved my issue.

Cheers, Ahmed

jQuery Mobile how to check if button is disabled?

You can use jQuery.is() function along with :disabled selector:

$("#savematerial").is(":disabled")

Chrome:The website uses HSTS. Network errors...this page will probably work later

Click anywhere in chrome window and type thisisunsafe (instead of badidea previously) in chrome.

This passphrase may change in future. This is the source

https://chromium.googlesource.com/chromium/src/+/master/components/security_interstitials/core/browser/resources/interstitial_large.js#19

According to that line, type window.atob('dGhpc2lzdW5zYWZl') to your browser console and it will give you the actual passphrase.

This time the passphrase is thisisunsafe.

How do I replace whitespaces with underscore?

This takes into account blank characters other than space and I think it's faster than using re module:

url = "_".join( title.split() )

Query to get only numbers from a string

declare @puvodni nvarchar(20)
set @puvodni = N'abc1d8e8ttr987avc'

WHILE PATINDEX('%[^0-9]%', @puvodni) > 0 SET @puvodni = REPLACE(@puvodni, SUBSTRING(@puvodni, PATINDEX('%[^0-9]%', @puvodni), 1), '' ) 

SELECT @puvodni

What is the difference between a "function" and a "procedure"?

This is a well-known old question, but I'd like to share some more insights about modern programming language research and design.

Basic answer

Traditionally (in the sense of structured programming) and informally, a procedure is a reusable structural construct to have "input" and to do something programmable. When something is needed to be done within a procedure, you can provide (actual) arguments to the procedure in a procedure call coded in the source code (usually in a kind of an expression), and the actions coded in the procedures body (provided in the definition of the procedure) will be executed with the substitution of the arguments into the (formal) parameters used in the body.

A function is more than a procedure because return values can also be specified as the "output" in the body. Function calls are more or less same to procedure calls, except that you can also use the result of the function call, syntactically (usually as a subexpression of some other expression).

Traditionally, procedure calls (rather than function calls) are used to indicate that no output must be interested, and there must be side effects to avoid the call being no-ops, hence emphasizing the imperative programming paradigm. Many traditional programming languages like Pascal provide both "procedures" and "functions" to distinguish this intentional difference of styles.

(To be clear, the "input" and "output" mentioned above are simplified notions based on the syntactic properties of functions. Many languages additionally support passing arguments to parameters by reference/sharing, to allow users transporting information encoded in arguments during the calls. Such parameter may even be just called as "in/out parameter". This feature is based on the nature of the objects being passed in the calls, which is orthogonal to the properties of the feature of procedure/function.)

However, if the result of a function call is not needed, it can be just (at least logically) ignored, and function definitions/function calls should be consistent to procedure definitions/procedure calls in this way. ALGOL-like languages like C, C++ and Java, all provide the feature of "function" in this fashion: by encoding the result type void as a special case of functions looking like traditional procedures, there is no need to provide the feature of "procedures" separately. This prevents some bloat in the language design.

Since SICP is mentioned, it is also worth noting that in the Scheme language specified by RnRS, a procedure may or may not have to return the result of the computation. This is the union of the traditional "function" (returning the result) and "procedure" (returning nothing), essentially same to the "function" concept of many ALGOL-like languages (and actually sharing even more guarantees like applicative evaluations of the operands before the call). However, old-fashion differences still occur even in normative documents like SRFI-96.

I don't know much about the exact reasons behind the divergence, but as I have experienced, it seems that language designers will be happier without specification bloat nowadays. That is, "procedure" as a standalone feature is unnecessary. Techniques like void type is already sufficient to mark the use where side effects should be emphasized. This is also more natural to users having experiences on C-like languages, which are popular more than a few decades. Moreover, it avoids the embarrassment in cases like RnRS where "procedures" are actually "functions" in the broader sense.

In theory, a function can be specified with a specified unit type as the type of the function call result to indicate that result is special. This distinguishes the traditional procedures (where the result of a call is uninterested) from others. There are different styles in the design of a language:

  • As in RnRS, just marking the uninterested results as "unspecified" value (of unspecified type, if the language has to mention it) and it is sufficient to be ignored.
  • Specifying the uninterested result as the value of a dedicated unit type (e.g. Kernel's #inert) also works.
  • When that type is a further a bottom type, it can be (hopefully) statically verified and prevented used as a type of expression. The void type in ALGOL-like languages is exactly an example of this technique. ISO C11's _Noreturn is a similar but more subtle one in this kind.

Further reading

As the traditional concept derived from math, there are tons of black magic most people do not bother to know. Strictly speaking, you won't be likely get the whole things clear as per your math books. CS books might not provide much help, either.

With concerning of programming languages, there are several caveats:

  • Functions in different branches of math are not always defined having same meanings. Functions in different programming paradigms may also be quite different (even sometimes the syntaxes of function call look similar). Sometimes the reasons to cause the differences are same, but sometimes they are not.
    • It is idiomatic to model computation by mathematical functions and then implement the underlying computation in programming languages. Be careful to avoid mapping them one to one unless you know what are being talked about.
  • Do not confuse the model with the entity be modeled.
    • The latter is only one of the implementation to the former. There can be more than one choices, depending on the contexts (the branches of math interested, for example).
    • In particular, it is more or less similarly absurd to treat "functions" as "mappings" or subsets of Cartesian products like to treat natural numbers as Von-Neumann encoding of ordinals (looking like a bunch of {{{}}, {}}...) besides some limited contexts.
  • Mathematically, functions can be partial or total. Different programming languages have different treatment here.
    • Some functional languages may honor totality of functions to guarantee the computation within the function calls always terminate in finite steps. However, this is essentially not Turing-complete, hence weaker computational expressiveness, and not much seen in general-purpose languages besides semantics of typechecking (which is expected to be total).
    • If the difference between the procedures and functions is significant, should there be "total procedures"? Hmm...
  • Constructs similar to functions in calculi used to model the general computation and the semantics of the programming languages (e.g. lambda abstractions in lambda calculi) can have different evaluation strategies on operands.
    • In traditional the reductions in pure calculi as well in as evaluations of expressions in pure functional languages, there are no side effects altering the results of the computations. As a result, operands are not required to be evaluated before the body of the functions-like constructs (because the invariant to define "same results" is kept by properties like ß-equivalence guaranteed by Church-Rosser property).
    • However, many programming languages may have side effects during the evaluations of expressions. That means, strict evaluation strategies like applicative evaluation are not the same to non-strict evaluation ones like call-by-need. This is significant, because without the distinction, there is no need to distinguish function-like (i.e. used with arguments) macros from (traditional) functions. But depending on the flavor of theories, this still can be an artifact. That said, in a broader sense, functional-like macros (esp. hygienic ones) are mathematical functions with some unnecessary limitations (syntactic phases). Without the limitations, it might be sane to treat (first-class) function-like macros as procedures...
    • For readers interested in this topic, consider some modern abstractions.
  • Procedures are usually considered out of the scope of traditional math. However, in calculi modeling the computation and programming language semantics, as well as contemporary programming language designs, there can be quite a big family of related concepts sharing the "callable" nature. Some of them are used to implement/extend/replace procedures/functions. There are even more subtle distinctions.

Android open pdf file

As of API 24, sending a file:// URI to another app will throw a FileUriExposedException. Instead, use FileProvider to send a content:// URI:

public File getFile(Context context, String fileName) {
    if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
        return null;
    }

    File storageDir = context.getExternalFilesDir(null);
    return new File(storageDir, fileName);
}

public Uri getFileUri(Context context, String fileName) {
    File file = getFile(context, fileName);
    return FileProvider.getUriForFile(context, BuildConfig.APPLICATION_ID + ".provider", file);
}

You must also define the FileProvider in your manifest:

<provider
    android:name="android.support.v4.content.FileProvider"
    android:authorities="com.mydomain.fileprovider"
    android:exported="false"
    android:grantUriPermissions="true">
    <meta-data
        android:name="android.support.FILE_PROVIDER_PATHS"
        android:resource="@xml/file_paths" />
</provider>

Example file_paths.xml:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-files-path name="name" path="path" />
</paths>

Replace "name" and "path" as appropriate.

To give the PDF viewer access to the file, you also have to add the FLAG_GRANT_READ_URI_PERMISSION flag to the intent:

private void displayPdf(String fileName) {
    Uri uri = getFileUri(this, fileName);

    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setDataAndType(uri, "application/pdf");

    // FLAG_GRANT_READ_URI_PERMISSION is needed on API 24+ so the activity opening the file can read it
    intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_GRANT_READ_URI_PERMISSION);

    if (intent.resolveActivity(getPackageManager()) == null) {
        // Show an error
    } else {
        startActivity(intent);
    }
}

See the FileProvider documentation for more details.

jQuery delete all table rows except first

This should work:

$(document).ready(function() {
   $("someTableSelector").find("tr:gt(0)").remove();
});

Setting Camera Parameters in OpenCV/Python

To avoid using integer values to identify the VideoCapture properties, one can use, e.g., cv2.cv.CV_CAP_PROP_FPS in OpenCV 2.4 and cv2.CAP_PROP_FPS in OpenCV 3.0. (See also Stefan's comment below.)

Here a utility function that works for both OpenCV 2.4 and 3.0:

# returns OpenCV VideoCapture property id given, e.g., "FPS"
def capPropId(prop):
  return getattr(cv2 if OPCV3 else cv2.cv,
    ("" if OPCV3 else "CV_") + "CAP_PROP_" + prop)

OPCV3 is set earlier in my utilities code like this:

from pkg_resources import parse_version
OPCV3 = parse_version(cv2.__version__) >= parse_version('3')

check if command was successful in a batch file

You can use

if errorlevel 1 echo Unsuccessful

in some cases. This depends on the last command returning a proper exit code. You won't be able to tell that there is anything wrong if your program returns normally even if there was an abnormal condition.

Caution with programs like Robocopy, which require a more nuanced approach, as the error level returned from that is a bitmask which contains more than just a boolean information and the actual success code is, AFAIK, 3.

What is the use of the square brackets [] in sql statements?

I believe it adds them there for consistency... they're only required when you have a space or special character in the column name, but it's cleaner to just include them all the time when the IDE generates SQL.

Setting Inheritance and Propagation flags with set-acl and powershell

Here's a table to help find the required flags for different permission combinations.

    +-----------------------------------------------------------------------------------------------------------------------------------------------------------+
    ¦             ¦ folder only ¦ folder, sub-folders and files ¦ folder and sub-folders ¦ folder and files ¦ sub-folders and files ¦ sub-folders ¦    files    ¦
    ¦-------------+-------------+-------------------------------+------------------------+------------------+-----------------------+-------------+-------------¦
    ¦ Propagation ¦ none        ¦ none                          ¦ none                   ¦ none             ¦ InheritOnly           ¦ InheritOnly ¦ InheritOnly ¦
    ¦ Inheritance ¦ none        ¦ Container|Object              ¦ Container              ¦ Object           ¦ Container|Object      ¦ Container   ¦ Object      ¦
    +-----------------------------------------------------------------------------------------------------------------------------------------------------------+

So, as David said, you'll want

InheritanceFlags.ContainerInherit | InheritanceFlags.ObjectInherit
PropagationFlags.None

How to find the location of the Scheduled Tasks folder

For Windows 7 and up, scheduled tasks are not run by cmd.exe, but rather by MMC (Microsoft Management Console). %SystemRoot%\Tasks should work on any other Windows version though.

jQuery - find child with a specific class

Based on your comment, moddify this:

$( '.bgHeaderH2' ).html (); // will return whatever is inside the DIV

to:

$( '.bgHeaderH2', $( this ) ).html (); // will return whatever is inside the DIV

More about selectors: https://api.jquery.com/category/selectors/

R * not meaningful for factors ERROR

new[,2] is a factor, not a numeric vector. Transform it first

new$MY_NEW_COLUMN <-as.numeric(as.character(new[,2])) * 5

Calculate row means on subset of columns

Calculate row means on a subset of columns:

Create a new data.frame which specifies the first column from DF as an column called ID and calculates the mean of all the other fields on that row, and puts that into column entitled 'Means':

data.frame(ID=DF[,1], Means=rowMeans(DF[,-1]))
  ID    Means
1  A 3.666667
2  B 4.333333
3  C 3.333333
4  D 4.666667
5  E 4.333333

Get Specific Columns Using “With()” Function in Laravel Eloquent

If you use PHP 7.4 or later you can also do it using arrow function so it looks cleaner:

Post::with(['user' => fn ($query) => $query->select('id','username')])->get();

How do I properly force a Git push?

I had the same question but figured it out finally. What you most likely need to do is run the following two git commands (replacing hash with the git commit revision number):

git checkout <hash>
git push -f HEAD:master

Disable Pinch Zoom on Mobile Web

Unfortunately, the offered solution doesn't work in Safari 10+, since Apple has decided to ignore user-scalable=no. This thread has more details and some JS hacks: disable viewport zooming iOS 10+ safari?

Where does Anaconda Python install on Windows?

If you installed as admin ( and meant for all users )

C:\ProgramData\Anaconda3\Scripts\anaconda.exe

If you install as a normal user

C:\Users\User-Name\AppData\Local\Continuum\Anaconda2\Scripts\anaconda.exe

Random integer in VB.NET

Function xrand() As Long
        Dim r1 As Long = Now.Day & Now.Month & Now.Year & Now.Hour & Now.Minute & Now.Second & Now.Millisecond
        Dim RAND As Long = Math.Max(r1, r1 * 2)
        Return RAND
End Function

[BBOYSE] This its the best way, from scratch :P

Google Maps setCenter()

For me above solutions didn't work then I tried

map.setCenter(new google.maps.LatLng(lat, lng));

and it worked as expected.

C# DataTable.Select() - How do I format the filter criteria to include null?

The way to check for null is to check for it:

DataRow[] myResultSet = myDataTable.Select("[COLUMN NAME] is null");

You can use and and or in the Select statement.

Fullscreen Activity in Android?

thanks for answer @Cristian i was getting error

android.util.AndroidRuntimeException: requestFeature() must be called before adding content

i solved this using

@Override
protected void onCreate(Bundle savedInstanceState) {

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    super.onCreate(savedInstanceState);

    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.activity_login);

    -----
    -----
}

CSS3 Spin Animation

To rotate, you can use key frames and a transform.

div {
    margin: 20px;
    width: 100px; 
    height: 100px;    
    background: #f00;
    -webkit-animation-name: spin;
    -webkit-animation-duration: 40000ms;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-timing-function: linear;
    -moz-animation-name: spin;
    -moz-animation-duration: 40000ms;
    -moz-animation-iteration-count: infinite;
    -moz-animation-timing-function: linear;
    -ms-animation-name: spin;
    -ms-animation-duration: 40000ms;
    -ms-animation-iteration-count: infinite;
    -ms-animation-timing-function: linear;
}

@-webkit-keyframes spin {
  from {
    -webkit-transform:rotate(0deg);
  }

  to {
    -webkit-transform:rotate(360deg);
  }
}

Example

How to disable Django's CSRF validation?

If you just need some views not to use CSRF, you can use @csrf_exempt:

from django.views.decorators.csrf import csrf_exempt

@csrf_exempt
def my_view(request):
    return HttpResponse('Hello world')

You can find more examples and other scenarios in the Django documentation:

How to count total lines changed by a specific author in a Git repository?

Here's a quick ruby script that corrals up the impact per user against a given log query.

For example, for rubinius:

Brian Ford: 4410668
Evan Phoenix: 1906343
Ryan Davis: 855674
Shane Becker: 242904
Alexander Kellett: 167600
Eric Hodel: 132986
Dirkjan Bussink: 113756
...

the script:

#!/usr/bin/env ruby

impact = Hash.new(0)

IO.popen("git log --pretty=format:\"%an\" --shortstat #{ARGV.join(' ')}") do |f|
  prev_line = ''
  while line = f.gets
    changes = /(\d+) insertions.*(\d+) deletions/.match(line)

    if changes
      impact[prev_line] += changes[1].to_i + changes[2].to_i
    end

    prev_line = line # Names are on a line of their own, just before the stats
  end
end

impact.sort_by { |a,i| -i }.each do |author, impact|
  puts "#{author.strip}: #{impact}"
end

Can an Android Toast be longer than Toast.LENGTH_LONG?

As mentioned by others Android Toasts can either be LENGTH_LONG or LENGTH_SHORT. There is no way around this, nor should you follow any of the 'hacks' posted.

The purpose of Toasts are to display "non-essential" information and due to their lingering effect, messages may be put far out of context if their duration exceeds a certain threshold. If stock Toasts were modified so that they can display longer than LENGTH_LONG the message would linger on the screen until the application's process is terminated as toast views are added to the WindowManager and not a ViewGroup in your app. I would assume this is why it is hard coded.

If you absolutely need to show a toast style message longer than three and a half seconds I recommend building a view that gets attached to the Activity's content, that way it will disappear when the user exits the application. My SuperToasts library deals with this issue and many others, feel free to use it! You would most likely be interested in using SuperActivityToasts

how to call service method from ng-change of select in angularjs?

You have at least two issues in your code:

  • ng-change="getScoreData(Score)

    Angular doesn't see getScoreData method that refers to defined service

  • getScoreData: function (Score, callback)

    We don't need to use callback since GET returns promise. Use then instead.

Here is a working example (I used random address only for simulation):

HTML

<select ng-model="score"
        ng-change="getScoreData(score)" 
        ng-options="score as score.name for score in  scores"></select>
    <pre>{{ScoreData|json}}</pre> 

JS

var fessmodule = angular.module('myModule', ['ngResource']);

fessmodule.controller('fessCntrl', function($scope, ScoreDataService) {

    $scope.scores = [{
        name: 'Bukit Batok Street 1',
        URL: 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, 153 Bukit Batok Street 1&sensor=true'
    }, {
        name: 'London 8',
        URL: 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, London 8&sensor=true'
    }];

    $scope.getScoreData = function(score) {
        ScoreDataService.getScoreData(score).then(function(result) {
            $scope.ScoreData = result;
        }, function(result) {
            alert("Error: No data returned");
        });
    };

});

fessmodule.$inject = ['$scope', 'ScoreDataService'];

fessmodule.factory('ScoreDataService', ['$http', '$q', function($http) {

    var factory = {
        getScoreData: function(score) {
            console.log(score);
            var data = $http({
                method: 'GET',
                url: score.URL
            });


            return data;
        }
    }
    return factory;
}]);

Demo Fiddle

How do I prevent a parent's onclick event from firing when a child anchor is clicked?

<a onclick="return false;" href="http://foo.com">I want to ignore my parent's onclick event.</a>

The POM for project is missing, no dependency information available

Change:

<!-- ANT4X -->
<dependency>
  <groupId>net.sourceforge</groupId>
  <artifactId>ant4x</artifactId>
  <version>${net.sourceforge.ant4x-version}</version>
  <scope>provided</scope>
</dependency>

To:

<!-- ANT4X -->
<dependency>
  <groupId>net.sourceforge.ant4x</groupId>
  <artifactId>ant4x</artifactId>
  <version>${net.sourceforge.ant4x-version}</version>
  <scope>provided</scope>
</dependency>

The groupId of net.sourceforge was incorrect. The correct value is net.sourceforge.ant4x.

Altering a column: null to not null

Making column not null and adding default can also be done in the SSMS GUI.

  1. As others have already stated, you can't set "not null" until all the existing data is "not null" like so:

UPDATE myTable SET myColumn = 0

  1. Once that's done, with the table in design view (right click on table and click "design view"), you can just uncheck the Allow Nulls columns like so:

enter image description here

  1. Still in design view with the column selected, you can see the Column Properties in the window below and set the default to 0 in there as well like so:

enter image description here

The OutputPath property is not set for this project

I have had similar issue on a Xamarin Project. It is maybe rare case but in case anyone else is having the issue. my project structure was like below

  • xamarin.Android project had a reference from xamarin.android.library project.
  • I created a plugin using some code from android.library project.
  • Now here is the problem. if you add project reference or nuget installation on xamarin.android library project. You will get this error. Developers assume that code was inside Android.Library project and i must reference the new plugin on this project. NO!
  • you must add a reference on Main Android project. because plugin->library->main project output isnt produced.

How do I verify/check/test/validate my SSH passphrase?

Extending @RobBednark's solution to a specific Windows + PuTTY scenario, you can do so:

  1. Generate SSH key pair with PuTTYgen (following Manually generating your SSH key in Windows), saving it to a PPK file;

  2. With the context menu in Windows Explorer, choose Edit with PuTTYgen. It will prompt for a password.

If you type the wrong password, it will just prompt again.

Note, if you like to type, use the following command on a folder that contains the PPK file: puttygen private-key.ppk -y.

Test if a vector contains a given element

is.element() makes for more readable code, and is identical to %in%

v <- c('a','b','c','e')

is.element('b', v)
'b' %in% v
## both return TRUE

is.element('f', v)
'f' %in% v
## both return FALSE

subv <- c('a', 'f')
subv %in% v
## returns a vector TRUE FALSE
is.element(subv, v)
## returns a vector TRUE FALSE

Extract hostname name from string

2020 answer

You don't need any extra dependencies for this! Depending on whether you need to optimize for performance or not, there are two good solutions:

1. Use URL.hostname for readability

In the Babel era, the cleanest and easiest solution is to use URL.hostname.

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const getHostname = (url) => {
  // use URL constructor and return hostname
  return new URL(url).hostname;
}

// tests
console.log(getHostname("https://stackoverflow.com/questions/8498592/extract-hostname-name-from-string/"));
console.log(getHostname("https://developer.mozilla.org/en-US/docs/Web/API/URL/hostname"));
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URL.hostname is part of the URL API, supported by all major browsers except IE (caniuse). Use a URL polyfill if you need to support legacy browsers.

Using this solution will also give you access to other URL properties and methods. This will be useful if you also want to extract the URL's pathname or query string params, for example.


2. Use RegEx for performance

URL.hostname is faster than using the anchor solution or parseUri. However it's still much slower than gilly3's regex:

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const getHostnameFromRegex = (url) => {
  // run against regex
  const matches = url.match(/^https?\:\/\/([^\/?#]+)(?:[\/?#]|$)/i);
  // extract hostname (will be null if no match is found)
  return matches && matches[1];
}

// tests
console.log(getHostnameFromRegex("https://stackoverflow.com/questions/8498592/extract-hostname-name-from-string/"));
console.log(getHostnameFromRegex("https://developer.mozilla.org/en-US/docs/Web/API/URL/hostname"));
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Test it yourself on this jsPerf


TL;DR

If you need to process a very large number of URLs (where performance would be a factor), use RegEx. Otherwise, use URL.hostname.

What is the most elegant way to check if all values in a boolean array are true?

OK. This is the "most elegant" solution I could come up with on the fly:

boolean allTrue = !Arrays.toString(myArray).contains("f");

Hope that helps!

How to check for a Null value in VB.NET

 If Short.TryParse(editTransactionRow.pay_id, New Short) Then editTransactionRow.pay_id.ToString()

Convert string to title case with JavaScript

I prefer the following over the other answers. It matches only the first letter of each word and capitalises it. Simpler code, easier to read and less bytes. It preserves existing capital letters to prevent distorting acronyms. However you can always call toLowerCase() on your string first.

function title(str) {
  return str.replace(/(^|\s)\S/g, function(t) { return t.toUpperCase() });
}

You can add this to your string prototype which will allow you to 'my string'.toTitle() as follows:

String.prototype.toTitle = function() {
  return this.replace(/(^|\s)\S/g, function(t) { return t.toUpperCase() });
}

Example:

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String.prototype.toTitle = function() {_x000D_
  return this.replace(/(^|\s)\S/g, function(t) { return t.toUpperCase() });_x000D_
}_x000D_
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console.log('all lower case ->','all lower case'.toTitle());_x000D_
console.log('ALL UPPER CASE ->','ALL UPPER CASE'.toTitle());_x000D_
console.log("I'm a little teapot ->","I'm a little teapot".toTitle());
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How to create a directory and give permission in single command

Just to expand on and improve some of the above answers:

First, I'll check the mkdir man page for GNU Coreutils 8.26 -- it gives us this information about the option '-m' and '-p' (can also be given as --mode=MODE and --parents, respectively):

...set[s] file mode (as in chmod), not a=rwx - umask

...no error if existing, make parent directories as needed

The statements are vague and unclear in my opinion. But basically, it says that you can make the directory with permissions specified by "chmod numeric notation" (octals) or you can go "the other way" and use a/your umask.

Side note: I say "the other way" since the umask value is actually exactly what it sounds like -- a mask, hiding/removing permissions rather than "granting" them as with chmod's numeric octal notation.

You can execute the shell-builtin command umask to see what your 3-digit umask is; for me, it's 022. This means that when I execute mkdir yodirectory in a given folder (say, mahome) and stat it, I'll get some output resembling this:

               755                   richard:richard         /mahome/yodirectory
 #          permissions                 user:group      what I just made (yodirectory),
 # (owner,group,others--in that order)                 where I made it (i.e. in mahome)
 # 

Now, to add just a tiny bit more about those octal permissions. When you make a directory, "your system" take your default directory perms' [which applies for new directories (its value should 777)] and slaps on yo(u)mask, effectively hiding some of those perms'. My umask is 022--now if we "subtract" 022 from 777 (technically subtracting is an oversimplification and not always correct - we are actually turning off perms or masking them)...we get 755 as stated (or "statted") earlier.

We can omit the '0' in front of the 3-digit octal (so they don't have to be 4 digits) since in our case we didn't want (or rather didn't mention) any sticky bits, setuids or setgids (you might want to look into those, btw, they might be useful since you are going 777). So in other words, 0777 implies (or is equivalent to) 777 (but 777 isn't necessarily equivalent to 0777--since 777 only specifies the permissions, not the setuids, setgids, etc.)

Now, to apply this to your question in a broader sense--you have (already) got a few options. All the answers above work (at least according to my coreutils). But you may (or are pretty likely to) run into problems with the above solutions when you want to create subdirectories (nested directories) with 777 permissions all at once. Specifically, if I do the following in mahome with a umask of 022:

mkdir -m 777 -p yodirectory/yostuff/mastuffinyostuff
# OR (you can swap 777 for 0777 if you so desire, outcome will be the same)
install -d -m 777 -p yodirectory/yostuff/mastuffinyostuff

I will get perms 755 for both yodirectory and yostuff, with only 777 perms for mastuffinyostuff. So it appears that the umask is all that's slapped on yodirectory and yostuff...to get around this we can use a subshell:

( umask 000 && mkdir -p yodirectory/yostuff/mastuffinyostuff )

and that's it. 777 perms for yostuff, mastuffinyostuff, and yodirectory.

javax.xml.bind.UnmarshalException: unexpected element. Expected elements are (none)

In our case we were getting UnmarshalException because a wrong Java package was specified in the following. The issue was resolved once the right package was in place:

@Bean
public Unmarshaller tmsUnmarshaller() {
    final Jaxb2Marshaller jaxb2Marshaller = new Jaxb2Marshaller();
    jaxb2Marshaller
            .setPackagesToScan("java.package.to.generated.java.classes.for.xsd");
    return jaxb2Marshaller;
}

Call a global variable inside module

If it is something that you reference but never mutate, then use const:

declare const bootbox;

load Js file in HTML

I had the same problem, and found the answer. If you use node.js with express, you need to give it its own function in order for the js file to be reached. For example:

const script = path.join(__dirname, 'script.js');
const server = express().get('/', (req, res) => res.sendFile(script))

Difference between map and collect in Ruby?

#collect is actually an alias for #map. That means the two methods can be used interchangeably, and effect the same behavior.

TypeScript - Append HTML to container element in Angular 2

There is a better solution to this answer that is more Angular based.

  1. Save your string in a variable in the .ts file

    MyStrings = ["one","two","three"]

  2. In the html file use *ngFor.

    <div class="one" *ngFor="let string of MyStrings; let i = index"> <div class="two">{{string}}</div> </div>

  3. if you want to dynamically insert the div element, just push more strings into the MyStrings array

    myFunction(nextString){ this.MyString.push(nextString) }

this way every time you click the button containing the myFunction(nextString) you effectively add another class="two" div which acts the same way as inserting it into the DOM with pure javascript.

How to connect to LocalDB in Visual Studio Server Explorer?

OK, answering to my own question.

Steps to connect LocalDB to Visual Studio Server Explorer

  1. Open command prompt
  2. Run SqlLocalDB.exe start v11.0
  3. Run SqlLocalDB.exe info v11.0
  4. Copy the Instance pipe name that starts with np:\...
  5. In Visual Studio select TOOLS > Connect to Database...
  6. For Server Name enter (localdb)\v11.0. If it didn't work, use the Instance pipe name that you copied earlier. You can also use this to connect with SQL Management Studio.
  7. Select the database on next dropdown list
  8. Click OK

enter image description here

jQuery get textarea text

Read textarea value and code-char conversion:

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function keys(e) {
  msg.innerHTML = `last key: ${String.fromCharCode(e.keyCode)}`
  
  if(e.key == 'Enter') {
    console.log('send: ', mycon.value);
    mycon.value='';
    e.preventDefault();
  }
}
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Push enter to 'send'<br>
<textarea id='mycon' onkeydown="keys(event)"></textarea>

<div id="msg"></div>
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And below nice Quake like console on div-s only :)

enter image description here

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document.addEventListener('keyup', keys);

let conShow = false

function keys(e) {
  if (e.code == 'Backquote') {
    conShow = !conShow;
    mycon.classList.toggle("showcon");
  } else {
    if (conShow) {
      if (e.code == "Enter") {
        conTextOld.innerHTML+= '<br>' + conText.innerHTML;
        let command=conText.innerHTML.replace(/&nbsp;/g,' ');
        conText.innerHTML='';
        console.log('Send to server:', command); 
      } 
      else if (e.code == "Backspace") {
        conText.innerHTML = conText.innerText.slice(0, -1);
      } else if (e.code == "Space") {
        conText.innerHTML = conText.innerText + '&nbsp;'
      } else {
        conText.innerHTML = conText.innerText + e.key;
      }

    }
  }
}
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body {
  margin: 0
}

.con {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: flex-start;
  width: 100%;
  height: 90px;
  background: rgba(255, 0, 0, 0.4);
  position: fixed;
  top: -90px;
  transition: top 0.5s ease-out 0.2s;
  font-family: monospace;
}

.showcon {
  top: 0px;
}

.conTextOld {
  color: white;
}

.line {
  display: flex;
  flex-direction: row;
}

.conText{   color: yellow; }

.carret {
  height: 20px;
  width: 10px;
  background: red;
  margin-left: 1px;
}

.start { color: red; margin-right: 2px}
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Click here and Press tilde ` (and Enter for "send")

<div id="mycon" class="con">
  <div id='conTextOld' class='conTextOld'>Hello!</div>
  <div class="line">
    <div class='start'> > </div>
    <div id='conText' class="conText"></div>
    <div class='carret'></div>
  </div>
</div>
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Validate select box

if (select == "") {
    alert("Please select a selection");
    return false;

That should work for you. It just did for me.

Best data type for storing currency values in a MySQL database

Though this may be late, but it will be helpful to someone else.From my experience and research I have come to know and accept decimal(19, 6).That is when working with php and mysql. when working with large amount of money and exchange rate

How to position background image in bottom right corner? (CSS)

This should do it:

<style>
body {
    background:url(bg.jpg) fixed no-repeat bottom right;
}
</style>

http://www.w3schools.com/cssref/pr_background-position.asp

Can I define a class name on paragraph using Markdown?

As mentioned above markdown itself leaves you hanging on this. However, depending on the implementation there are some workarounds:

At least one version of MD considers <div> to be a block level tag but <DIV> is just text. All broswers however are case insensitive. This allows you to keep the syntax simplicity of MD, at the cost of adding div container tags.

So the following is a workaround:

<DIV class=foo>

  Paragraphs here inherit class foo from above.

</div>

The downside of this is that the output code has <p> tags wrapping the <div> lines (both of them, the first because it's not and the second because it doesn't match. No browser fusses about this that I've found, but the code won't validate. MD tends to put in spare <p> tags anyway.

Several versions of markdown implement the convention <tag markdown="1"> in which case MD will do the normal processing inside the tag. The above example becomes:

<div markdown="1" class=foo>

  Paragraphs here inherit class foo from above.

</div>

The current version of Fletcher's MultiMarkdown allows attributes to follow the link if using referenced links.

Change directory in PowerShell

Unlike the CMD.EXE CHDIR or CD command, the PowerShell Set-Location cmdlet will change drive and directory, both. Get-Help Set-Location -Full will get you more detailed information on Set-Location, but the basic usage would be

PS C:\> Set-Location -Path Q:\MyDir

PS Q:\MyDir> 

By default in PowerShell, CD and CHDIR are alias for Set-Location.

(Asad reminded me in the comments that if the path contains spaces, it must be enclosed in quotes.)

Android - how to make a scrollable constraintlayout?

Please use below solution it has taken my lots of time to fix.

Enjoy your time :)

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<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white"
    >

    <ScrollView
        android:id="@+id/mainScroll"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:fillViewport="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentStart="true">
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">


            <android.support.constraint.ConstraintLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                android:layout_alignParentStart="true"
                android:layout_alignParentTop="true"
                android:layout_alignParentBottom="true"
                android:layout_alignParentEnd="true"
                >

            </android.support.constraint.ConstraintLayout>

        </RelativeLayout>
    </ScrollView>
</RelativeLayout>
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Use Exactly like this u will definitely find your solution...

What is the difference between document.location.href and document.location?

The document.location is an object that contains properties for the current location.

The href property is one of these properties, containing the complete URL, i.e. all the other properties put together.

Some browsers allow you to assign an URL to the location object and acts as if you assigned it to the href property. Some other browsers are more picky, and requires you to use the href property. Thus, to make the code work in all browsers, you have to use the href property.

Both the window and document objects has a location object. You can set the URL using either window.location.href or document.location.href. However, logically the document.location object should be read-only (as you can't change the URL of a document; changing the URL loads a new document), so to be on the safe side you should rather use window.location.href when you want to set the URL.

Label python data points on plot

How about print (x, y) at once.

from matplotlib import pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)

A = -0.75, -0.25, 0, 0.25, 0.5, 0.75, 1.0
B = 0.73, 0.97, 1.0, 0.97, 0.88, 0.73, 0.54

plt.plot(A,B)
for xy in zip(A, B):                                       # <--
    ax.annotate('(%s, %s)' % xy, xy=xy, textcoords='data') # <--

plt.grid()
plt.show()

enter image description here

Integrating the ZXing library directly into my Android application

The

compile 'com.google.zxing:core:2.3.0'

unfortunately didn't work for me.

This is what worked for me:

dependencies {
   compile 'com.journeyapps:zxing-android-embedded:3.0.1@aar'
   compile 'com.google.zxing:core:3.2.0'
}

Please find the link here: https://github.com/journeyapps/zxing-android-embedded

Docker build gives "unable to prepare context: context must be a directory: /Users/tempUser/git/docker/Dockerfile"

One of the reasons for me getting an error was the file name make sure the file name is Dockerfile So i figured it out, hope it might help someone.

Using jQuery to test if an input has focus

There is a plugin to check if an element is focused: http://plugins.jquery.com/project/focused

$('input').each(function(){
   if ($(this) == $.focused()) {
      $(this).addClass('focused');
   }
})

How do I 'overwrite', rather than 'merge', a branch on another branch in Git?

If you just want the two branches 'email' and 'staging' to be the same, you can tag the 'email' branch, then reset the 'email' branch to the 'staging' one:

$ git checkout email
$ git tag old-email-branch
$ git reset --hard staging

You can also rebase the 'staging' branch on the 'email' branch. But the result will contains the modification of the two branches.

React-router v4 this.props.history.push(...) not working

It seems things have changed around a bit in the latest version of react router. You can now access history via the context. this.context.history.push('/path')

Also see the replies to the this github issue: https://github.com/ReactTraining/react-router/issues/4059

Spark Dataframe distinguish columns with duplicated name

Lets start with some data:

from pyspark.mllib.linalg import SparseVector
from pyspark.sql import Row

df1 = sqlContext.createDataFrame([
    Row(a=107831, f=SparseVector(
        5, {0: 0.0, 1: 0.0, 2: 0.0, 3: 0.0, 4: 0.0})),
    Row(a=125231, f=SparseVector(
        5, {0: 0.0, 1: 0.0, 2: 0.0047, 3: 0.0, 4: 0.0043})),
])

df2 = sqlContext.createDataFrame([
    Row(a=107831, f=SparseVector(
        5, {0: 0.0, 1: 0.0, 2: 0.0, 3: 0.0, 4: 0.0})),
    Row(a=107831, f=SparseVector(
        5, {0: 0.0, 1: 0.0, 2: 0.0, 3: 0.0, 4: 0.0})),
])

There are a few ways you can approach this problem. First of all you can unambiguously reference child table columns using parent columns:

df1.join(df2, df1['a'] == df2['a']).select(df1['f']).show(2)

##  +--------------------+
##  |                   f|
##  +--------------------+
##  |(5,[0,1,2,3,4],[0...|
##  |(5,[0,1,2,3,4],[0...|
##  +--------------------+

You can also use table aliases:

from pyspark.sql.functions import col

df1_a = df1.alias("df1_a")
df2_a = df2.alias("df2_a")

df1_a.join(df2_a, col('df1_a.a') == col('df2_a.a')).select('df1_a.f').show(2)

##  +--------------------+
##  |                   f|
##  +--------------------+
##  |(5,[0,1,2,3,4],[0...|
##  |(5,[0,1,2,3,4],[0...|
##  +--------------------+

Finally you can programmatically rename columns:

df1_r = df1.select(*(col(x).alias(x + '_df1') for x in df1.columns))
df2_r = df2.select(*(col(x).alias(x + '_df2') for x in df2.columns))

df1_r.join(df2_r, col('a_df1') == col('a_df2')).select(col('f_df1')).show(2)

## +--------------------+
## |               f_df1|
## +--------------------+
## |(5,[0,1,2,3,4],[0...|
## |(5,[0,1,2,3,4],[0...|
## +--------------------+

Is a DIV inside a TD a bad idea?

After checking the XHTML DTD I discovered that a <TD>-element is allowed to contain block elements like headings, lists and also <DIV>-elements. Thus, using a <DIV>-element inside a <TD>-element does not violate the XHTML standard. I'm pretty sure that other modern variations of HTML have an equivalent content model for the <TD>-element.

Here are the relevant DTD rules:

<!ELEMENT td %Flow;>
<!-- %Flow; mixes block and inline and is used for list items etc. -->
<!ENTITY %Flow "(#PCDATA | %block; | form | %inline; | %misc;>
<!ENTITY %block "p | %heading; | div | %lists; | %blocktext; | fieldset | table">

Convert String to Carbon

Why not try using the following:

$dateTimeString = $aDateString." ".$aTimeString;
$dueDateTime = Carbon::createFromFormat('Y-m-d H:i:s', $dateTimeString, 'Europe/London');   

CSS div element - how to show horizontal scroll bars only?

You shouldn't get both horizontal and vertical scrollbars unless you make the content large enough to require them.

However you typically do in IE due to a bug. Check in other browsers (Firefox etc.) to find out whether it is in fact only IE that is doing it.

IE6-7 (amongst other browsers) supports the proposed CSS3 extension to set scrollbars independently, which you could use to suppress the vertical scrollbar:

overflow: auto;
overflow-y: hidden;

You may also need to add for IE8:

-ms-overflow-y: hidden;

as Microsoft are threatening to move all pre-CR-standard properties into their own ‘-ms’ box in IE8 Standards Mode. (This would have made sense if they'd always done it that way, but is rather an inconvenience for everyone now.)

On the other hand it's entirely possible IE8 will have fixed the bug anyway.

How to try convert a string to a Guid

new Guid(string)

You could also look at using a TypeConverter.

How to manually install a pypi module without pip/easy_install?

  1. Download the package
  2. unzip it if it is zipped
  3. cd into the directory containing setup.py
  4. If there are any installation instructions contained in documentation contianed herein, read and follow the instructions OTHERWISE
  5. type in python setup.py install

You may need administrator privileges for step 5. What you do here thus depends on your operating system. For example in Ubuntu you would say sudo python setup.py install

EDIT- thanks to kwatford (see first comment)

To bypass the need for administrator privileges during step 5 above you may be able to make use of the --user flag. In this way you can install the package only for the current user.

The docs say:

Files will be installed into subdirectories of site.USER_BASE (written as userbase hereafter). This scheme installs pure Python modules and extension modules in the same location (also known as site.USER_SITE). Here are the values for UNIX, including Mac OS X:

More details can be found here: http://docs.python.org/2.7/install/index.html

React : difference between <Route exact path="/" /> and <Route path="/" />

In short, if you have multiple routes defined for your app's routing, enclosed with Switch component like this;

<Switch>

  <Route exact path="/" component={Home} />
  <Route path="/detail" component={Detail} />

  <Route exact path="/functions" component={Functions} />
  <Route path="/functions/:functionName" component={FunctionDetails} />

</Switch>

Then you have to put exact keyword to the Route which it's path is also included by another Route's path. For example home path / is included in all paths so it needs to have exact keyword to differentiate it from other paths which start with /. The reason is also similar to /functions path. If you want to use another route path like /functions-detail or /functions/open-door which includes /functions in it then you need to use exact for the /functions route.

jQuery Ajax error handling, show custom exception messages

This function basically generates unique random API key's and in case if it doesn't then pop-up dialog box with error message appears

In View Page:

<div class="form-group required">
    <label class="col-sm-2 control-label" for="input-storename"><?php echo $entry_storename; ?></label>
    <div class="col-sm-6">
        <input type="text" class="apivalue"  id="api_text" readonly name="API" value="<?php echo strtoupper(substr(md5(rand().microtime()), 0, 12)); ?>" class="form-control" />                                                                    
        <button type="button" class="changeKey1" value="Refresh">Re-Generate</button>
    </div>
</div>

<script>
$(document).ready(function(){
    $('.changeKey1').click(function(){
          debugger;
        $.ajax({
                url  :"index.php?route=account/apiaccess/regenerate",
                type :'POST',
                dataType: "json",
                async:false,
                contentType: "application/json; charset=utf-8",
                success: function(data){
                  var result =  data.sync_id.toUpperCase();
                        if(result){
                          $('#api_text').val(result);
                        }
                  debugger;
                  },
                error: function(xhr, ajaxOptions, thrownError) {
                  alert(thrownError + "\r\n" + xhr.statusText + "\r\n" + xhr.responseText);
                }

        });
    });
  });
</script>

From Controller:

public function regenerate(){
    $json = array();
    $api_key = substr(md5(rand(0,100).microtime()), 0, 12);
    $json['sync_id'] = $api_key; 
    $json['message'] = 'Successfully API Generated';
    $this->response->addHeader('Content-Type: application/json');
    $this->response->setOutput(json_encode($json));
}

The optional callback parameter specifies a callback function to run when the load() method is completed. The callback function can have different parameters:

Type: Function( jqXHR jqXHR, String textStatus, String errorThrown )

A function to be called if the request fails. The function receives three arguments: The jqXHR (in jQuery 1.4.x, XMLHttpRequest) object, a string describing the type of error that occurred and an optional exception object, if one occurred. Possible values for the second argument (besides null) are "timeout", "error", "abort", and "parsererror". When an HTTP error occurs, errorThrown receives the textual portion of the HTTP status, such as "Not Found" or "Internal Server Error." As of jQuery 1.5, the error setting can accept an array of functions. Each function will be called in turn. Note: This handler is not called for cross-domain script and cross-domain JSONP requests.

Track a new remote branch created on GitHub

First of all you have to fetch the remote repository:

git fetch remoteName

Than you can create the new branch and set it up to track the remote branch you want:

git checkout -b newLocalBranch remoteName/remoteBranch

You can also use "git branch --track" instead of "git checkout -b" as max specified.

git branch --track newLocalBranch remoteName/remoteBranch

Elegant ways to support equivalence ("equality") in Python classes

The 'is' test will test for identity using the builtin 'id()' function which essentially returns the memory address of the object and therefore isn't overloadable.

However in the case of testing the equality of a class you probably want to be a little bit more strict about your tests and only compare the data attributes in your class:

import types

class ComparesNicely(object):

    def __eq__(self, other):
        for key, value in self.__dict__.iteritems():
            if (isinstance(value, types.FunctionType) or 
                    key.startswith("__")):
                continue

            if key not in other.__dict__:
                return False

            if other.__dict__[key] != value:
                return False

         return True

This code will only compare non function data members of your class as well as skipping anything private which is generally what you want. In the case of Plain Old Python Objects I have a base class which implements __init__, __str__, __repr__ and __eq__ so my POPO objects don't carry the burden of all that extra (and in most cases identical) logic.

How to exclude a directory from ant fileset, based on directories contents

I think one way is first to check whether your file exists and if it exists to exclude the folder from copy:

<target name="excludeLocales">

    <property name="de-DE.file" value="${basedir}/locale/de-DE/incompelte.flag"/>
    <available property="de-DE.file.exists" file="${de-DE.file}" />

    <copy todir="C:/temp/">
        <fileset dir="${basedir}/locale">
            <exclude name="de-DE/**" if="${de-DE.file.exists}"/>
            <include name="xy/**"/>
        </fileset>
    </copy>
</target>

This should work also for the other languages.

A SQL Query to select a string between two known strings

Hope this helps : Declared a variable , in case of any changes need to be made thats only once .

declare @line  varchar(100)

set @line ='[email protected]'

select SUBSTRING(@line ,(charindex('-',@line)+1), CHARINDEX('@',@line)-charindex('-',@line)-1)

How to tell which disk Windows Used to Boot

a simpler way search downloads in the start menu and click on downloads in the search results to see where it will take you the drive will be highlighted in the explorer.

ASP.NET MVC 3 Razor - Adding class to EditorFor

You can use:

@Html.EditorFor(x => x.Created, new { htmlAttributes = new { @class = "date" } })

(At least with ASP.NET MVC 5, but I do not know how that was with ASP.NET MVC 3.)

How to find if element with specific id exists or not

 var myEle = document.getElementById("myElement");
    if(myEle){
        var myEleValue= myEle.value;
    }

the return of getElementById is null if an element is not actually present inside the dom, so your if statement will fail, because null is considered a false value

How would I run an async Task<T> method synchronously?

Try following code it works for me:

public async void TaskSearchOnTaskList (SearchModel searchModel)
{
    try
    {
        List<EventsTasksModel> taskSearchList = await Task.Run(
            () => MakeasyncSearchRequest(searchModel),
            cancelTaskSearchToken.Token);

        if (cancelTaskSearchToken.IsCancellationRequested
                || string.IsNullOrEmpty(rid_agendaview_search_eventsbox.Text))
        {
            return;
        }

        if (taskSearchList == null || taskSearchList[0].result == Constants.ZERO)
        {
            RunOnUiThread(() => {
                textViewNoMembers.Visibility = ViewStates.Visible;                  
                taskListView.Visibility = ViewStates.Gone;
            });

            taskSearchRecureList = null;

            return;
        }
        else
        {
            taskSearchRecureList = TaskFooterServiceLayer
                                       .GetRecurringEvent(taskSearchList);

            this.SetOnAdapter(taskSearchRecureList);
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine("ActivityTaskFooter -> TaskSearchOnTaskList:" + ex.Message);
    }
}

Any way to replace characters on Swift String?

var str = "This is my string"
str = str.replacingOccurrences(of: " ", with: "+")
print(str)

This action could not be completed. Try Again (-22421)

For Xcode 8.3.2

i have resolved same issue

"This action could not be completed. Try Again (-22421)"

using following steps...

  1. Quit your xcode (if open)
  2. in Application Folder, Xcode 8.3.2 -->Show Package Contents -->Contents -->Application -->Application Loader (Show package contents) -->Contents -->itms -->bin -->iTMSTransporter (right click and Open with Terminal, it will auto start updating...) after updating open your project, rebuild your archive and upload it again..

For Xcode 9

issue

”This action could not be completed. Try Again (-22421)”

has been Resolved in Xcode 9. Now, we can upload app through Xcode Organizer also.

https://developer.apple.com/library/content/releasenotes/DeveloperTools/RN-Xcode/Chapters/Introduction.html#//apple_ref/doc/uid/TP40001051-CH1-SW876

Setting dynamic scope variables in AngularJs - scope.<some_string>

If you were trying to do what I imagine you were trying to do, then you only have to treat scope like a regular JS object.

This is what I use for an API success response for JSON data array...

function(data){

    $scope.subjects = [];

    $.each(data, function(i,subject){
        //Store array of data types
        $scope.subjects.push(subject.name);

        //Split data in to arrays
        $scope[subject.name] = subject.data;
    });
}

Now {{subjects}} will return an array of data subject names, and in my example there would be a scope attribute for {{jobs}}, {{customers}}, {{staff}}, etc. from $scope.jobs, $scope.customers, $scope.staff

jQuery check if <input> exists and has a value

if($('#user_inp').length > 0 && $('#user_inp').val() != '')
{

    $('#user_inp').css({"font-size":"18px"});
    $('#user_line').css({"background-color":"#4cae4c","transition":"0.5s","height":"2px"});
    $('#username').css({"color":"#4cae4c","transition":"0.5s","font-size":"18px"});

}

How should I store GUID in MySQL tables?

The GuidToBinary routine posted by KCD should be tweaked to account for the bit layout of the timestamp in the GUID string. If the string represents a version 1 UUID, like those returned by the uuid() mysql routine, then the time components are embedded in letters 1-G, excluding the D.

12345678-9ABC-DEFG-HIJK-LMNOPQRSTUVW
12345678 = least significant 4 bytes of the timestamp in big endian order
9ABC     = middle 2 timestamp bytes in big endian
D        = 1 to signify a version 1 UUID
EFG      = most significant 12 bits of the timestamp in big endian

When you convert to binary, the best order for indexing would be: EFG9ABC12345678D + the rest.

You don't want to swap 12345678 to 78563412 because big endian already yields the best binary index byte order. However, you do want the most significant bytes moved in front of the lower bytes. Hence, EFG go first, followed by the middle bits and lower bits. Generate a dozen or so UUIDs with uuid() over the course of a minute and you should see how this order yields the correct rank.

select uuid(), 0
union 
select uuid(), sleep(.001)
union 
select uuid(), sleep(.010)
union 
select uuid(), sleep(.100)
union 
select uuid(), sleep(1)
union 
select uuid(), sleep(10)
union
select uuid(), 0;

/* output */
6eec5eb6-9755-11e4-b981-feb7b39d48d6
6eec5f10-9755-11e4-b981-feb7b39d48d6
6eec8ddc-9755-11e4-b981-feb7b39d48d6
6eee30d0-9755-11e4-b981-feb7b39d48d6
6efda038-9755-11e4-b981-feb7b39d48d6
6f9641bf-9755-11e4-b981-feb7b39d48d6
758c3e3e-9755-11e4-b981-feb7b39d48d6 

The first two UUIDs were generated closest in time. They only vary in the last 3 nibbles of the first block. These are the least significant bits of the timestamp, which means we want to push them to the right when we convert this to an indexable byte array. As a counter example, the last ID is the most current, but the KCD's swapping algorithm would put it before the 3rd ID (3e before dc, last bytes from the first block).

The correct order for indexing would be:

1e497556eec5eb6... 
1e497556eec5f10... 
1e497556eec8ddc... 
1e497556eee30d0... 
1e497556efda038... 
1e497556f9641bf... 
1e49755758c3e3e... 

See this article for supporting information: http://mysql.rjweb.org/doc.php/uuid

*** note that I don't split the version nibble from the high 12 bits of the timestamp. This is the D nibble from your example. I just throw it in front. So my binary sequence ends up being DEFG9ABC and so on. This implies that all my indexed UUIDs start with the same nibble. The article does the same thing.

Convert month name to month number in SQL Server

How about this?

select DATEPART(MM,'january 01 2011') -- returns 1
select DATEPART(MM,'march 01 2011')  -- returns 3
select DATEPART(MM,'august 01 2011') -- returns 8

Resize Google Maps marker icon image

As mentionned in comments, this is the updated solution in favor of Icon object with documentation.

Use Icon object

var icon = {
    url: "../res/sit_marron.png", // url
    scaledSize: new google.maps.Size(50, 50), // scaled size
    origin: new google.maps.Point(0,0), // origin
    anchor: new google.maps.Point(0, 0) // anchor
};

 posicion = new google.maps.LatLng(latitud,longitud)
 marker = new google.maps.Marker({
  position: posicion,
  map: map,
  icon: icon
 });

AngularJS - How to use $routeParams in generating the templateUrl?

Router:-

...
.when('/enquiry/:page', {
    template: '<div ng-include src="templateUrl" onload="onLoad()"></div>',
    controller: 'enquiryCtrl'
})
...

Controller:-

...
// template onload event
$scope.onLoad = function() {
    console.log('onLoad()');
    f_tcalInit();  // or other onload stuff
}

// initialize
$scope.templateUrl = 'ci_index.php/adminctrl/enquiry/'+$routeParams.page;
...

I believe it is a weakness in angularjs that $routeParams is NOT visible inside the router. A tiny enhancement would make a world of difference during implementation.

Expand a div to fill the remaining width

This would be a good example of something that's trivial to do with tables and hard (if not impossible, at least in a cross-browser sense) to do with CSS.

If both the columns were fixed width, this would be easy.

If one of the columns was fixed width, this would be slightly harder but entirely doable.

With both columns variable width, IMHO you need to just use a two-column table.

The endpoint reference (EPR) for the Operation not found is

In my case it was caused by a wrong Content-Type in the HTTP POST. Setting it to text/xml solved the problem.

Change color inside strings.xml

Use CDATA in the below way for formatting your text

<resources>
<string name="app_name">DemoShareActionButton</string>
<string name="intro_message">
    <b>
    <![CDATA[ This sample shows you how a provide a context-sensitive ShareActionProvider.
    ]]>
    </b>
    </string>

Just add any tag you want before the <![CDATA[ and you will get your proper output.

Ruby 'require' error: cannot load such file

Another nice little method is to include the current directory in your load path with

$:.unshift('.')

You could push it onto the $: ($LOAD_PATH) array but unshift will force it to load your current working directory before the rest of the load path.

Once you've added your current directory in your load path you don't need to keep specifying

 require './tokenizer' 

and can just go back to using

require 'tokenizer'

Adding days to $Date in PHP

From PHP 5.2 on you can use modify with a DateTime object:

http://php.net/manual/en/datetime.modify.php

$Date1 = '2010-09-17';
$date = new DateTime($Date1);
$date->modify('+1 day');
$Date2 = $date->format('Y-m-d');

Be careful when adding months... (and to a lesser extent, years)

HTML-5 date field shows as "mm/dd/yyyy" in Chrome, even when valid date is set

I have same problem and i found solution which is given below with full datepicker using simple HTML,Javascript and CSS. In this code i prepare formate like dd/mm/yyyy but you can work any.

HTML Code:

    <body>
<input type="date" id="dt" onchange="mydate1();" hidden/>
<input type="text" id="ndt"  onclick="mydate();" hidden />
<input type="button" Value="Date" onclick="mydate();" />
</body>

CSS Code:

#dt{text-indent: -500px;height:25px; width:200px;}

Javascript Code :

function mydate()
{
  //alert("");
document.getElementById("dt").hidden=false;
document.getElementById("ndt").hidden=true;
}
function mydate1()
{
 d=new Date(document.getElementById("dt").value);
dt=d.getDate();
mn=d.getMonth();
mn++;
yy=d.getFullYear();
document.getElementById("ndt").value=dt+"/"+mn+"/"+yy
document.getElementById("ndt").hidden=false;
document.getElementById("dt").hidden=true;
}

Output:

enter image description here

Getting all names in an enum as a String[]

Basing off from Bohemian's answer for Kotlin:

Use replace() instead of replaceAll().

Arrays.toString(MyEnum.values()).replace(Regex("^.|.$"), "").split(", ").toTypedArray()

Side note: Convert to .toTypedArray() for use in AlertDialog's setSingleChoiceItems, for example.

How do I add images in laravel view?

normaly is better image store in public folder (because it has write permission already that you can use when I upload images to it)

public
    upload_media
         photos
            image.png


$image  = public_path() . '/upload_media/photos/image.png'; // destination path

view PHP

<img src="<?= $image ?>">

View blade

<img src="{{ $image }}">

Getting coordinates of marker in Google Maps API

var lat = homeMarker.getPosition().lat();
var lng = homeMarker.getPosition().lng();

See the google.maps.LatLng docs and google.maps.Marker getPosition().

What is the difference between bool and Boolean types in C#

Note that Boolean will only work were you have using System; (which is usually, but not necessarily, included) (unless you write it out as System.Boolean). bool does not need using System;

JavaScript, Node.js: is Array.forEach asynchronous?

Although Array.forEach is not asynchronous, you can get asynchronous "end result". Example below:

_x000D_
_x000D_
function delayFunction(x) {
    return new Promise(
        (resolve) => setTimeout(() => resolve(x), 1000)
    );
}

[1, 2, 3].forEach(async(x) => {
    console.log(x);
    console.log(await delayFunction(x));
});
_x000D_
_x000D_
_x000D_

How to duplicate sys.stdout to a log file?

another solution using logging module:

import logging
import sys

log = logging.getLogger('stdxxx')

class StreamLogger(object):

    def __init__(self, stream, prefix=''):
        self.stream = stream
        self.prefix = prefix
        self.data = ''

    def write(self, data):
        self.stream.write(data)
        self.stream.flush()

        self.data += data
        tmp = str(self.data)
        if '\x0a' in tmp or '\x0d' in tmp:
            tmp = tmp.rstrip('\x0a\x0d')
            log.info('%s%s' % (self.prefix, tmp))
            self.data = ''


logging.basicConfig(level=logging.INFO,
                    filename='text.log',
                    filemode='a')

sys.stdout = StreamLogger(sys.stdout, '[stdout] ')

print 'test for stdout'

How to use an existing database with an Android application

You can do this by using a content provider. Each data item used in the application remains private to the application. If an application want to share data accross applications, there is only technique to achieve this, using a content provider, which provides interface to access that private data.

MySQL Workbench Edit Table Data is read only

This is the Known limitation in MySQLWorkbench (you can't edit table w/o PK):

To Edit the Table:

Method 1: (method not working in somecases)
right-click on a table within the Object Browser and choose the Edit Table Data option from there.

Method 2:
I would rather suggest you to add Primary Key Instead:

ALTER TABLE `your_table_name` ADD PRIMARY KEY (`column_name`);

and you might want to remove the existing rows first:

Truncate table your_table_name

Compare two objects in Java with possible null values

For these cases it would be better to use Apache Commons StringUtils#equals, it already handles null strings. Code sample:

public boolean compare(String s1, String s2) {
    return StringUtils.equals(s1, s2);
}

If you dont want to add the library, just copy the source code of the StringUtils#equals method and apply it when you need it.