What's the best strategy for unit-testing database-driven applications?

I'm always running tests against an in-memory DB (HSQLDB or Derby) for these reasons:

It makes you think which data to keep in your test DB and why. Just hauling your production DB into a test system translates to "I have no idea what I'm doing or why and if something breaks, it wasn't me!!" ;)
It makes sure the database can be recreated with little effort in a new place (for example when we need to replicate a bug from production)
It helps enormously with the quality of the DDL files.

The in-memory DB is loaded with fresh data once the tests start and after most tests, I invoke ROLLBACK to keep it stable. ALWAYS keep the data in the test DB stable! If the data changes all the time, you can't test.

The data is loaded from SQL, a template DB or a dump/backup. I prefer dumps if they are in a readable format because I can put them in VCS. If that doesn't work, I use a CSV file or XML. If I have to load enormous amounts of data ... I don't. You never have to load enormous amounts of data :) Not for unit tests. Performance tests are another issue and different rules apply.

how to get the ipaddress of a virtual box running on local machine

ifconfig
ip addr show

If you used NAT for your virtual machine settings(your machine ip will be 10.0.2.15), then you have to use port forwarding to connect to machine. IP address will be 127.0.0.1

If you used bridged networking/Host only networking, then you will have separate Ip address. Use that IP address to connect virtual machine

Getting "project" nuget configuration is invalid error

Simply restarting Visual Studio worked for me.

How to reset postgres' primary key sequence when it falls out of sync?

~~ALTER SEQUENCE sequence_name RESTART WITH (SELECT max(id) FROM table_name);~~ Doesn't work.

Copied from @tardate answer:

SELECT setval(pg_get_serial_sequence('table_name', 'id'), MAX(id)) FROM table_name;

How to Empty Caches and Clean All Targets Xcode 4 and later

In addition to doing the following, you may experience this issue if your app's Storyboard's files are localized. First, do each of these:

Clean Build
Reset Simulator
Restart Xcode
Delete your DerivedData folder in ~/Library/Developer/Xcode/DerivedData
Restart Computer

What finally worked for me was re-generating the storyboard localization files and deleting the English localization (which was unneeded because the Base Locale is English). To reload your Storyboard strings, see this answer on StackOverflow.

I had noticed that the non-text parts of my Storyboard were being updated, but not the localized text. If you have a localization in your app, I would recommend checking to make sure your localizations are updated (even if they're .strings files).

how to hide <li> bullets in navigation menu and footer links BUT show them for listing items

Let's say you're using this HTML5 layout:

<html>
    <body>
        <header>
            <nav><ul>...</ul></nav>
        </header>
        <article>
            <ul>...</ul>
        </article>
        <footer>
            <ul>...</ul>
        </footer>
    </body>
</html>

You could say in your CSS:

header ul, footer ul, nav ul { list-style-type: none; }

If you're using HTML 4, assign IDs to your DIVs (instead of using the new fancy-pants elements) and change this to:

#header ul, #footer ul, #nav ul { list-style-type: none; }

If you're using a CSS reset stylesheet (like Eric Meyer's), you would actually have to give the list style back, since the reset removes the list style from all lists.

#content ul { list-style-type: disc; margin-left: 1.5em; }

Textarea onchange detection

It's 2012, the post-PC era is here, and we still have to struggle with something as basic as this. This ought to be very simple.

Until such time as that dream is fulfilled, here's the best way to do this, cross-browser: use a combination of the input and onpropertychange events, like so:

var area = container.querySelector('textarea');
if (area.addEventListener) {
  area.addEventListener('input', function() {
    // event handling code for sane browsers
  }, false);
} else if (area.attachEvent) {
  area.attachEvent('onpropertychange', function() {
    // IE-specific event handling code
  });
}

The input event takes care of IE9+, FF, Chrome, Opera and Safari, and onpropertychange takes care of IE8 (it also works with IE6 and 7, but there are some bugs).

The advantage of using input and onpropertychange is that they don't fire unnecessarily (like when pressing the Ctrl or Shift keys); so if you wish to run a relatively expensive operation when the textarea contents change, this is the way to go.

Now IE, as always, does a half-assed job of supporting this: neither input nor onpropertychange fires in IE when characters are deleted from the textarea. So if you need to handle deletion of characters in IE, use keypress (as opposed to using keyup / keydown, because they fire only once even if the user presses and holds a key down).

Source: http://www.alistapart.com/articles/expanding-text-areas-made-elegant/

EDIT: It seems even the above solution is not perfect, as rightly pointed out in the comments: the presence of the addEventListener property on the textarea does not imply you're working with a sane browser; similarly the presence of the attachEvent property does not imply IE. If you want your code to be really air-tight, you should consider changing that. See Tim Down's comment for pointers.

Get latitude and longitude based on location name with Google Autocomplete API

Enter the location by Autocomplete and rest of all the fields: latitude and Longititude values get automatically filled.
Replace API KEY with your Google API key

<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no">
<meta charset="utf-8">
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false&libraries=places"></script>

<link type="text/css" rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500">
</head>

<body>
<textarea placeholder="Enter Area name to populate Latitude and Longitude" name="address" onFocus="initializeAutocomplete()" id="locality" ></textarea><br>

<input type="text" name="city" id="city" placeholder="City" value="" ><br>
<input type="text" name="latitude" id="latitude" placeholder="Latitude" value="" ><br>
<input type="text" name="longitude" id="longitude" placeholder="Longitude" value="" ><br>
<input type="text" name="place_id" id="location_id" placeholder="Location Ids" value="" ><br>

<script type="text/javascript">
  function initializeAutocomplete(){
    var input = document.getElementById('locality');
    // var options = {
    //   types: ['(regions)'],
    //   componentRestrictions: {country: "IN"}
    // };
    var options = {}

    var autocomplete = new google.maps.places.Autocomplete(input, options);

    google.maps.event.addListener(autocomplete, 'place_changed', function() {
      var place = autocomplete.getPlace();
      var lat = place.geometry.location.lat();
      var lng = place.geometry.location.lng();
      var placeId = place.place_id;
      // to set city name, using the locality param
      var componentForm = {
        locality: 'short_name',
      };
      for (var i = 0; i < place.address_components.length; i++) {
        var addressType = place.address_components[i].types[0];
        if (componentForm[addressType]) {
          var val = place.address_components[i][componentForm[addressType]];
          document.getElementById("city").value = val;
        }
      }
      document.getElementById("latitude").value = lat;
      document.getElementById("longitude").value = lng;
      document.getElementById("location_id").value = placeId;
    });
  }
</script>
</body>
</html>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="//maps.googleapis.com/maps/api/js?libraries=places&key=API KEY"></script>


<script src="https://fonts.googleapis.com/css?family=Roboto:300,400,500></script>

How to change the font and font size of an HTML input tag?

in your css :

 #txtComputer {
      font-size: 24px;
 }

You can style an input entirely (background, color, etc.) and even use the hover event.

Maven build Compilation error : Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project Maven

I had the same problem and I Changed this

<configuration>
    <source>1.7</source>
    <target>1.7</target>
 </configuration>

here 1.7 is my JDK version.it was solved.

this.getClass().getClassLoader().getResource("...") and NullPointerException

When eclipse runs the test case it will look for the file in target/classes not src/test/resources. When the resource is saved eclipse should copy it from src/test/resources to target/classes if it has changed but if for some reason this has not happened then you will get this error. Check that the file exists in target/classes to see if this is the problem.

How to remove the bottom border of a box with CSS

You can either set

border-bottom: none;

border-bottom: 0;

One sets the border-style to none.
One sets the border-width to 0px.

_x000D_

div {_x000D_
  border: 3px solid #900;_x000D_
_x000D_
  background-color: limegreen; _x000D_
  width:  28vw;_x000D_
  height: 10vw;_x000D_
  margin:  1vw;_x000D_
  text-align: center;_x000D_
  float: left;_x000D_
}_x000D_
_x000D_
.stylenone {_x000D_
  border-bottom: none;_x000D_
}_x000D_
.widthzero {_x000D_
  border-bottom: 0;_x000D_
}

_x000D_

<div>_x000D_
(full border)_x000D_
</div>_x000D_
<div class="stylenone">_x000D_
(style)<br><br>_x000D_
_x000D_
border-bottom: none;_x000D_
</div>_x000D_
<div class="widthzero">_x000D_
(width)<br><br>_x000D_
border-bottom: 0;_x000D_
</div>

_x000D_

Side Note:
If you ever have to track down why a border is not showing when you expect it to, It is also good to know that either of these could be the culprit. Also verify the border-color is not the same as the background-color.

How to add an element to the beginning of an OrderedDict?

I would suggest adding a prepend() method to this pure Python ActiveState recipe or deriving a subclass from it. The code to do so could be a fairly efficient given that the underlying data structure for ordering is a linked-list.

Update

To prove this approach is feasible, below is code that does what's suggested. As a bonus, I also made a few additional minor changes to get to work in both Python 2.7.15 and 3.7.1.

A prepend() method has been added to the class in the recipe and has been implemented in terms of another method that's been added named move_to_end(), which was added to OrderedDict in Python 3.2.

prepend() can also be implemented directly, almost exactly as shown at the beginning of @Ashwini Chaudhary's answer—and doing so would likely result in it being slightly faster, but that's been left as an exercise for the motivated reader...

# Ordered Dictionary for Py2.4 from https://code.activestate.com/recipes/576693

# Backport of OrderedDict() class that runs on Python 2.4, 2.5, 2.6, 2.7 and pypy.
# Passes Python2.7's test suite and incorporates all the latest updates.

try:
    from thread import get_ident as _get_ident
except ImportError:  # Python 3
#    from dummy_thread import get_ident as _get_ident
    from _thread import get_ident as _get_ident  # Changed - martineau

try:
    from _abcoll import KeysView, ValuesView, ItemsView
except ImportError:
    pass

class MyOrderedDict(dict):
    'Dictionary that remembers insertion order'
    # An inherited dict maps keys to values.
    # The inherited dict provides __getitem__, __len__, __contains__, and get.
    # The remaining methods are order-aware.
    # Big-O running times for all methods are the same as for regular dictionaries.

    # The internal self.__map dictionary maps keys to links in a doubly linked list.
    # The circular doubly linked list starts and ends with a sentinel element.
    # The sentinel element never gets deleted (this simplifies the algorithm).
    # Each link is stored as a list of length three:  [PREV, NEXT, KEY].

    def __init__(self, *args, **kwds):
        '''Initialize an ordered dictionary.  Signature is the same as for
        regular dictionaries, but keyword arguments are not recommended
        because their insertion order is arbitrary.

        '''
        if len(args) > 1:
            raise TypeError('expected at most 1 arguments, got %d' % len(args))
        try:
            self.__root
        except AttributeError:
            self.__root = root = []  # sentinel node
            root[:] = [root, root, None]
            self.__map = {}
        self.__update(*args, **kwds)

    def prepend(self, key, value):  # Added to recipe.
        self.update({key: value})
        self.move_to_end(key, last=False)

    #### Derived from cpython 3.2 source code.
    def move_to_end(self, key, last=True):  # Added to recipe.
        '''Move an existing element to the end (or beginning if last==False).

        Raises KeyError if the element does not exist.
        When last=True, acts like a fast version of self[key]=self.pop(key).
        '''
        PREV, NEXT, KEY = 0, 1, 2

        link = self.__map[key]
        link_prev = link[PREV]
        link_next = link[NEXT]
        link_prev[NEXT] = link_next
        link_next[PREV] = link_prev
        root = self.__root

        if last:
            last = root[PREV]
            link[PREV] = last
            link[NEXT] = root
            last[NEXT] = root[PREV] = link
        else:
            first = root[NEXT]
            link[PREV] = root
            link[NEXT] = first
            root[NEXT] = first[PREV] = link
    ####

    def __setitem__(self, key, value, dict_setitem=dict.__setitem__):
        'od.__setitem__(i, y) <==> od[i]=y'
        # Setting a new item creates a new link which goes at the end of the linked
        # list, and the inherited dictionary is updated with the new key/value pair.
        if key not in self:
            root = self.__root
            last = root[0]
            last[1] = root[0] = self.__map[key] = [last, root, key]
        dict_setitem(self, key, value)

    def __delitem__(self, key, dict_delitem=dict.__delitem__):
        'od.__delitem__(y) <==> del od[y]'
        # Deleting an existing item uses self.__map to find the link which is
        # then removed by updating the links in the predecessor and successor nodes.
        dict_delitem(self, key)
        link_prev, link_next, key = self.__map.pop(key)
        link_prev[1] = link_next
        link_next[0] = link_prev

    def __iter__(self):
        'od.__iter__() <==> iter(od)'
        root = self.__root
        curr = root[1]
        while curr is not root:
            yield curr[2]
            curr = curr[1]

    def __reversed__(self):
        'od.__reversed__() <==> reversed(od)'
        root = self.__root
        curr = root[0]
        while curr is not root:
            yield curr[2]
            curr = curr[0]

    def clear(self):
        'od.clear() -> None.  Remove all items from od.'
        try:
            for node in self.__map.itervalues():
                del node[:]
            root = self.__root
            root[:] = [root, root, None]
            self.__map.clear()
        except AttributeError:
            pass
        dict.clear(self)

    def popitem(self, last=True):
        '''od.popitem() -> (k, v), return and remove a (key, value) pair.
        Pairs are returned in LIFO order if last is true or FIFO order if false.

        '''
        if not self:
            raise KeyError('dictionary is empty')
        root = self.__root
        if last:
            link = root[0]
            link_prev = link[0]
            link_prev[1] = root
            root[0] = link_prev
        else:
            link = root[1]
            link_next = link[1]
            root[1] = link_next
            link_next[0] = root
        key = link[2]
        del self.__map[key]
        value = dict.pop(self, key)
        return key, value

    # -- the following methods do not depend on the internal structure --

    def keys(self):
        'od.keys() -> list of keys in od'
        return list(self)

    def values(self):
        'od.values() -> list of values in od'
        return [self[key] for key in self]

    def items(self):
        'od.items() -> list of (key, value) pairs in od'
        return [(key, self[key]) for key in self]

    def iterkeys(self):
        'od.iterkeys() -> an iterator over the keys in od'
        return iter(self)

    def itervalues(self):
        'od.itervalues -> an iterator over the values in od'
        for k in self:
            yield self[k]

    def iteritems(self):
        'od.iteritems -> an iterator over the (key, value) items in od'
        for k in self:
            yield (k, self[k])

    def update(*args, **kwds):
        '''od.update(E, **F) -> None.  Update od from dict/iterable E and F.

        If E is a dict instance, does:           for k in E: od[k] = E[k]
        If E has a .keys() method, does:         for k in E.keys(): od[k] = E[k]
        Or if E is an iterable of items, does:   for k, v in E: od[k] = v
        In either case, this is followed by:     for k, v in F.items(): od[k] = v

        '''
        if len(args) > 2:
            raise TypeError('update() takes at most 2 positional '
                            'arguments (%d given)' % (len(args),))
        elif not args:
            raise TypeError('update() takes at least 1 argument (0 given)')
        self = args[0]
        # Make progressively weaker assumptions about "other"
        other = ()
        if len(args) == 2:
            other = args[1]
        if isinstance(other, dict):
            for key in other:
                self[key] = other[key]
        elif hasattr(other, 'keys'):
            for key in other.keys():
                self[key] = other[key]
        else:
            for key, value in other:
                self[key] = value
        for key, value in kwds.items():
            self[key] = value

    __update = update  # let subclasses override update without breaking __init__

    __marker = object()

    def pop(self, key, default=__marker):
        '''od.pop(k[,d]) -> v, remove specified key and return the corresponding value.
        If key is not found, d is returned if given, otherwise KeyError is raised.

        '''
        if key in self:
            result = self[key]
            del self[key]
            return result
        if default is self.__marker:
            raise KeyError(key)
        return default

    def setdefault(self, key, default=None):
        'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od'
        if key in self:
            return self[key]
        self[key] = default
        return default

    def __repr__(self, _repr_running={}):
        'od.__repr__() <==> repr(od)'
        call_key = id(self), _get_ident()
        if call_key in _repr_running:
            return '...'
        _repr_running[call_key] = 1
        try:
            if not self:
                return '%s()' % (self.__class__.__name__,)
            return '%s(%r)' % (self.__class__.__name__, self.items())
        finally:
            del _repr_running[call_key]

    def __reduce__(self):
        'Return state information for pickling'
        items = [[k, self[k]] for k in self]
        inst_dict = vars(self).copy()
        for k in vars(MyOrderedDict()):
            inst_dict.pop(k, None)
        if inst_dict:
            return (self.__class__, (items,), inst_dict)
        return self.__class__, (items,)

    def copy(self):
        'od.copy() -> a shallow copy of od'
        return self.__class__(self)

    @classmethod
    def fromkeys(cls, iterable, value=None):
        '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S
        and values equal to v (which defaults to None).

        '''
        d = cls()
        for key in iterable:
            d[key] = value
        return d

    def __eq__(self, other):
        '''od.__eq__(y) <==> od==y.  Comparison to another OD is order-sensitive
        while comparison to a regular mapping is order-insensitive.

        '''
        if isinstance(other, MyOrderedDict):
            return len(self)==len(other) and self.items() == other.items()
        return dict.__eq__(self, other)

    def __ne__(self, other):
        return not self == other

    # -- the following methods are only used in Python 2.7 --

    def viewkeys(self):
        "od.viewkeys() -> a set-like object providing a view on od's keys"
        return KeysView(self)

    def viewvalues(self):
        "od.viewvalues() -> an object providing a view on od's values"
        return ValuesView(self)

    def viewitems(self):
        "od.viewitems() -> a set-like object providing a view on od's items"
        return ItemsView(self)

if __name__ == '__main__':

    d1 = MyOrderedDict([('a', '1'), ('b', '2')])
    d1.update({'c':'3'})
    print(d1)  # -> MyOrderedDict([('a', '1'), ('b', '2'), ('c', '3')])

    d2 = MyOrderedDict([('a', '1'), ('b', '2')])
    d2.prepend('c', 100)
    print(d2)  # -> MyOrderedDict([('c', 100), ('a', '1'), ('b', '2')])

EF Migrations: Rollback last applied migration?

In case there is a possibility for dataloss EF does not complete the update-database command since AutomaticMigrationDataLossAllowed = false by default, and roolbacks the action unless you run it with the -force parameter.

Update-Database –TargetMigration:"Your migration name" -force

Update-Database –TargetMigration:Your_Migration_Index -force

Best way to randomize an array with .NET

Here's a simple way using OLINQ:

// Input array
List<String> lst = new List<string>();
for (int i = 0; i < 500; i += 1) lst.Add(i.ToString());

// Output array
List<String> lstRandom = new List<string>();

// Randomize
Random rnd = new Random();
lstRandom.AddRange(from s in lst orderby rnd.Next(100) select s);

How to find cube root using Python?

You could use x ** (1. / 3) to compute the (floating-point) cube root of x.

The slight subtlety here is that this works differently for negative numbers in Python 2 and 3. The following code, however, handles that:

def is_perfect_cube(x):
    x = abs(x)
    return int(round(x ** (1. / 3))) ** 3 == x

print(is_perfect_cube(63))
print(is_perfect_cube(64))
print(is_perfect_cube(65))
print(is_perfect_cube(-63))
print(is_perfect_cube(-64))
print(is_perfect_cube(-65))
print(is_perfect_cube(2146689000)) # no other currently posted solution
                                   # handles this correctly

This takes the cube root of x, rounds it to the nearest integer, raises to the third power, and finally checks whether the result equals x.

The reason to take the absolute value is to make the code work correctly for negative numbers across Python versions (Python 2 and 3 treat raising negative numbers to fractional powers differently).

JNI and Gradle in Android Studio

Gradle Build Tools 2.2.0+ - The closest the NDK has ever come to being called 'magic'

In trying to avoid experimental and frankly fed up with the NDK and all its hackery I am happy that 2.2.x of the Gradle Build Tools came out and now it just works. The key is the externalNativeBuild and pointing ndkBuild path argument at an Android.mk or change ndkBuild to cmake and point the path argument at a CMakeLists.txt build script.

android {
    compileSdkVersion 19
    buildToolsVersion "25.0.2"

    defaultConfig {
        minSdkVersion 19
        targetSdkVersion 19

        ndk {
            abiFilters 'armeabi', 'armeabi-v7a', 'x86'
        }

        externalNativeBuild {
            cmake {
                cppFlags '-std=c++11'
                arguments '-DANDROID_TOOLCHAIN=clang',
                        '-DANDROID_PLATFORM=android-19',
                        '-DANDROID_STL=gnustl_static',
                        '-DANDROID_ARM_NEON=TRUE',
                        '-DANDROID_CPP_FEATURES=exceptions rtti'
            }
        }
    }

    externalNativeBuild {
        cmake {
             path 'src/main/jni/CMakeLists.txt'
        }
        //ndkBuild {
        //   path 'src/main/jni/Android.mk'
        //}
    }
}

For much more detail check Google's page on adding native code.

After this is setup correctly you can ./gradlew installDebug and off you go. You will also need to be aware that the NDK is moving to clang since gcc is now deprecated in the Android NDK.

Android Studio Clean and Build Integration - DEPRECATED

The other answers do point out the correct way to prevent the automatic creation of Android.mk files, but they fail to go the extra step of integrating better with Android Studio. I have added the ability to actually clean and build from source without needing to go to the command-line. Your local.properties file will need to have ndk.dir=/path/to/ndk

apply plugin: 'com.android.application'

android {
    compileSdkVersion 14
    buildToolsVersion "20.0.0"

    defaultConfig {
        applicationId "com.example.application"
        minSdkVersion 14
        targetSdkVersion 14

        ndk {
            moduleName "YourModuleName"
        }
    }

    sourceSets.main {
        jni.srcDirs = [] // This prevents the auto generation of Android.mk
        jniLibs.srcDir 'src/main/libs' // This is not necessary unless you have precompiled libraries in your project.
    }

    task buildNative(type: Exec, description: 'Compile JNI source via NDK') {
        def ndkDir = android.ndkDirectory
        commandLine "$ndkDir/ndk-build",
                '-C', file('src/main/jni').absolutePath, // Change src/main/jni the relative path to your jni source
                '-j', Runtime.runtime.availableProcessors(),
                'all',
                'NDK_DEBUG=1'
    }

    task cleanNative(type: Exec, description: 'Clean JNI object files') {
        def ndkDir = android.ndkDirectory
        commandLine "$ndkDir/ndk-build",
                '-C', file('src/main/jni').absolutePath, // Change src/main/jni the relative path to your jni source
                'clean'
    }

    clean.dependsOn 'cleanNative'

    tasks.withType(JavaCompile) {
        compileTask -> compileTask.dependsOn buildNative
    }
}

dependencies {
    compile 'com.android.support:support-v4:20.0.0'
}

The src/main/jni directory assumes a standard layout of the project. It should be the relative from this build.gradle file location to the jni directory.

Gradle - for those having issues

Also check this Stack Overflow answer.

It is really important that your gradle version and general setup are correct. If you have an older project I highly recommend creating a new one with the latest Android Studio and see what Google considers the standard project. Also, use gradlew. This protects the developer from a gradle version mismatch. Finally, the gradle plugin must be configured correctly.

And you ask what is the latest version of the gradle plugin? Check the tools page and edit the version accordingly.

Final product - /build.gradle

// Top-level build file where you can add configuration options common to all sub-projects/modules.

// Running 'gradle wrapper' will generate gradlew - Getting gradle wrapper working and using it will save you a lot of pain.
task wrapper(type: Wrapper) {
    gradleVersion = '2.2'
}

// Look Google doesn't use Maven Central, they use jcenter now.
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:1.2.0'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

Make sure gradle wrapper generates the gradlew file and gradle/wrapper subdirectory. This is a big gotcha.

ndkDirectory

This has come up a number of times, but android.ndkDirectory is the correct way to get the folder after 1.1. Migrating Gradle Projects to version 1.0.0. If you're using an experimental or ancient version of the plugin your mileage may vary.

File Not Found when running PHP with Nginx

I had been having the same issues, And during my tests, I have faced both problems:

1º: "File not found"

and

2º: 404 Error page

And I found out that, in my case:

I had to mount volumes for my public folders both on the Nginx volumes and the PHP volumes.

If it's mounted in Nginx and is not mounted in PHP, it will give: "File not found"

Examples (Will show "File not found error"):


services:
  php-fpm:
    build:
      context: ./docker/php-fpm
  nginx:
    build:
      context: ./docker/nginx
    volumes:
        #Nginx Global Configurations
      - ./docker/nginx/nginx.conf:/etc/nginx/nginx.conf
      - ./docker/nginx/conf.d/:/etc/nginx/conf.d

        #Nginx Configurations for you Sites:

        # - Nginx Server block
      - ./sites/example.com/site.conf:/etc/nginx/sites-available/example.com.conf
        # - Copy Public Folder:
      - ./sites/example.com/root/public/:/var/www/example.com/public
    ports:
      - "80:80"
      - "443:443"
    depends_on:
      - php-fpm
    restart: always

If it's mounted in PHP and is not mounted in Nginx, it will give a 404 Page Not Found error.

Example (Will throw 404 Page Not Found Error):

version: '3'

services:
  php-fpm:
    build:
      context: ./docker/php-fpm
    volumes:
      - ./sites/example.com/root/public/:/var/www/example.com/public
  nginx:
    build:
      context: ./docker/nginx
    volumes:
        #Nginx Global Configurations
      - ./docker/nginx/nginx.conf:/etc/nginx/nginx.conf
      - ./docker/nginx/conf.d/:/etc/nginx/conf.d

        #Nginx Configurations for you Sites:

        # - Nginx Server block
      - ./sites/example.com/site.conf:/etc/nginx/sites-available/example.com.conf
    ports:
      - "80:80"
      - "443:443"
    depends_on:
      - php-fpm
    restart: always

And this would work just fine (mounting on both sides) (Assuming everything else is well configured and you're facing the same problem as me):

version: '3'

services:
  php-fpm:
    build:
      context: ./docker/php-fpm
    volumes:
      # Mount PHP for Public Folder
      - ./sites/example.com/root/public/:/var/www/example.com/public
  nginx:
    build:
      context: ./docker/nginx
    volumes:
        #Nginx Global Configurations
      - ./docker/nginx/nginx.conf:/etc/nginx/nginx.conf
      - ./docker/nginx/conf.d/:/etc/nginx/conf.d

        #Nginx Configurations for you Sites:

        # - Nginx Server block
      - ./sites/example.com/site.conf:/etc/nginx/sites-available/example.com.conf
        # - Copy Public Folder:
      - ./sites/example.com/root/public/:/var/www/example.com/public
    ports:
      - "80:80"
      - "443:443"
    depends_on:
      - php-fpm
    restart: always

Also here's a Full working example project using Nginx/Php, for serving multiple sites: https://github.com/Pablo-Camara/simple-multi-site-docker-compose-nginx-alpine-php-fpm-alpine-https-ssl-certificates

I hope this helps someone, And if anyone knows more about this please let me know, Thanks!

How do I run PHP code when a user clicks on a link?

either send the user to another page which does it

<a href="exec.php">Execute PHP</a>

or do it with ajax

<script type="text/javascript">
// <![CDATA[
    document.getElementById('link').onclick = function() {
        // call script via ajax...
        return false;
    }
// ]]>
</script>
...
<a href="#" id="link">Execute PHP</a>

How can I check if an InputStream is empty without reading from it?

If the InputStream you're using supports mark/reset support, you could also attempt to read the first byte of the stream and then reset it to its original position:

input.mark(1);
final int bytesRead = input.read(new byte[1]);
input.reset();
if (bytesRead != -1) {
    //stream not empty
} else {
    //stream empty
}

If you don't control what kind of InputStream you're using, you can use the markSupported() method to check whether mark/reset will work on the stream, and fall back to the available() method or the java.io.PushbackInputStream method otherwise.

Horizontal scroll on overflow of table

Unless I grossly misunderstood your question, move overflow-x:scroll from .search-table to .search-table-outter.

http://jsfiddle.net/ZXnqM/4/

.search-table-outter {border:2px solid red; overflow-x:scroll;}
.search-table{table-layout: fixed; margin:40px auto 0px auto;   }

As far as I know you can't give scrollbars to tables themselves.

HashMap allows duplicates?

Hashmap type Overwrite that key if hashmap key is same key

map.put("1","1111");
map.put("1","2222");

output

key:value
1:2222

How to call same method for a list of objects?

The approach

for item in all:
    item.start()

is simple, easy, readable, and concise. This is the main approach Python provides for this operation. You can certainly encapsulate it in a function if that helps something. Defining a special function for this for general use is likely to be less clear than just writing out the for loop.

How do I create a local database inside of Microsoft SQL Server 2014?

As per comments, First you need to install an instance of SQL Server if you don't already have one - https://msdn.microsoft.com/en-us/library/ms143219.aspx

Once this is installed you must connect to this instance (server) and then you can create a database here - https://msdn.microsoft.com/en-US/library/ms186312.aspx

Install Qt on Ubuntu

Also take a look at awesome project aqtinstall https://github.com/miurahr/aqtinstall/ (it can install any Qt version on Linux, Mac and Windows machines without any interaction!) and GitHub Action that uses this tool: https://github.com/jurplel/install-qt-action

Why Local Users and Groups is missing in Computer Management on Windows 10 Home?

Windows 10 Home Edition does not have Local Users and Groups option so that is the reason you aren't able to see that in Computer Management.

You can use User Accounts by pressing Window+R, typing netplwiz and pressing OK as described here.

Validating file types by regular expression

You can embed case insensitity into the regular expression like so:

\.(?i:)(?:jpg|gif|doc|pdf)$

Initializing a two dimensional std::vector

Suppose you want to initialize a two dimensional integer vector with n rows and m column each having value 'VAL'

Write it as

std::vector<vector<int>> arr(n, vector<int>(m,VAL));

This VAL can be a integer type variable or constant such as 100

How to copy files from 'assets' folder to sdcard?

Using some of the concepts in the answers to this question, I wrote up a class called AssetCopier to make copying /assets/ simple. It's available on github and can be accessed with jitpack.io:

new AssetCopier(MainActivity.this)
        .withFileScanning()
        .copy("tocopy", destDir);

See https://github.com/flipagram/android-assetcopier for more details.

How to integrate Dart into a Rails app

If you run pub build --mode=debug the build directory contains the application without symlinks. The Dart code should be retained when --mode=debug is used.

Here is some discussion going on about this topic too Dart and it's place in Rails Assets Pipeline

Using import fs from 'fs'

If we are using TypeScript, we can update the type definition file by running the command npm install @types/node from the terminal or command prompt.

The most efficient way to remove first N elements in a list?

Python lists were not made to operate on the beginning of the list and are very ineffective at this operation.

While you can write

mylist = [1, 2 ,3 ,4]
mylist.pop(0)

It's very inefficient.

If you only want to delete items from your list, you can do this with del:

del mylist[:n]

Which is also really fast:

In [34]: %%timeit
help=range(10000)
while help:
    del help[:1000]
   ....:
10000 loops, best of 3: 161 µs per loop

If you need to obtain elements from the beginning of the list, you should use collections.deque by Raymond Hettinger and its popleft() method.

from collections import deque

deque(['f', 'g', 'h', 'i', 'j'])

>>> d.pop()                          # return and remove the rightmost item
'j'
>>> d.popleft()                      # return and remove the leftmost item
'f'

A comparison:

list + pop(0)

In [30]: %%timeit
   ....: help=range(10000)
   ....: while help:
   ....:     help.pop(0)
   ....:
100 loops, best of 3: 17.9 ms per loop

deque + popleft()

In [33]: %%timeit
help=deque(range(10000))
while help:
    help.popleft()
   ....:
1000 loops, best of 3: 812 µs per loop

PHP float with 2 decimal places: .00

You can use this simple function. number_format ()

    $num = 2214.56;

    // default english notation
    $english_format = number_format($num);
    // 2,215

    // French notation
    $format_francais = number_format($num, 2, ',', ' ');
    // 2 214,56

    $num1 = 2234.5688;

   // English notation with thousands separator
    $english_format_number = number_format($num1,2);
    // 2,234.57

    // english notation without thousands separator
    $english_format_number2 = number_format($num1, 2, '.', '');
    // 2234.57

How to call code behind server method from a client side JavaScript function?

Try creating a new service and calling it. The processing can be done there, and returned back.

http://code.msdn.microsoft.com/windowsazure/WCF-Azure-AJAX-Calculator-4cf3099e

function makeCall(operation){
    var n1 = document.getElementById("num1").value;
    var n2 = document.getElementById("num2").value;
if(n1 && n2){

        // Instantiate a service proxy
        var proxy = new Service();

        // Call correct operation on vf cproxy       
        switch(operation){

            case "gridOne":
                proxy.Calculate(AjaxService.Operation.getWeather, n1, n2,
 onSuccess, onFail, null);

****HTML CODE****
<p>Major City: <input type="text" id="num1" onclick="return num1_onclick()"
/></p>
<p>Country: <input type="text" id="num2" onclick="return num2_onclick()"
/></p> 
<input id="btnDivide" type="button" onclick="return makeCall('gridOne');"

Uploading file using POST request in Node.js

An undocumented feature of the formData field that request implements is the ability to pass options to the form-data module it uses:

request({
  url: 'http://example.com',
  method: 'POST',
  formData: {
    'regularField': 'someValue',
    'regularFile': someFileStream,
    'customBufferFile': {
      value: fileBufferData,
      options: {
        filename: 'myfile.bin'
      }
    }
  }
}, handleResponse);

This is useful if you need to avoid calling requestObj.form() but need to upload a buffer as a file. The form-data module also accepts contentType (the MIME type) and knownLength options.

This change was added in October 2014 (so 2 months after this question was asked), so it should be safe to use now (in 2017+). This equates to version v2.46.0 or above of request.

mysqldump exports only one table

In case you encounter an error like this

mysqldump: 1044 Access denied when using LOCK TABLES

A quick workaround is to pass the –-single-transaction option to mysqldump.

So your command will be like this.

mysqldump --single-transaction -u user -p DBNAME > backup.sql

Ordering issue with date values when creating pivot tables

I saw this somewhere else. I am using 2016 Excel. What worked for me was to use YYYY Quarters (I was looking for quarterly data). So, I had the source data sorted as YYYY xQ. 2016 1Q, 2016 2Q, 2016 3Q, 2016, 4Q, 2017 1Q, 2017 2Q... You get the idea.

Set icon for Android application

Right click your project, go to New > Other > Android > Android Icon Set

Then follow the instructions on the Wizard

How to count the number of set bits in a 32-bit integer?

From Hacker's Delight, p. 66, Figure 5-2

int pop(unsigned x)
{
    x = x - ((x >> 1) & 0x55555555);
    x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
    x = (x + (x >> 4)) & 0x0F0F0F0F;
    x = x + (x >> 8);
    x = x + (x >> 16);
    return x & 0x0000003F;
}

Executes in ~20-ish instructions (arch dependent), no branching.

Hacker's Delight is delightful! Highly recommended.

Merge a Branch into Trunk

The syntax is wrong, it should instead be

svn merge <what(the range)> <from(your dev branch)> <to(trunk/trunk local copy)>

how to stop a loop arduino

This isn't published on Arduino.cc but you can in fact exit from the loop routine with a simple exit(0);

This will compile on pretty much any board you have in your board list. I'm using IDE 1.0.6. I've tested it with Uno, Mega, Micro Pro and even the Adafruit Trinket

void loop() {
// All of your code here

/* Note you should clean up any of your I/O here as on exit, 
all 'ON'outputs remain HIGH */

// Exit the loop 
exit(0);  //The 0 is required to prevent compile error.
}

I use this in projects where I wire in a button to the reset pin. Basically your loop runs until exit(0); and then just persists in the last state. I've made some robots for my kids, and each time the press a button (reset) the code starts from the start of the loop() function.

Replace Line Breaks in a String C#

I would use Environment.Newline when I wanted to insert a newline for a string, but not to remove all newlines from a string.

Depending on your platform you can have different types of newlines, but even inside the same platform often different types of newlines are used. In particular when dealing with file formats and protocols.

string ReplaceNewlines(string blockOfText, string replaceWith)
{
    return blockOfText.Replace("\r\n", replaceWith).Replace("\n", replaceWith).Replace("\r", replaceWith);
}

Remove all files except some from a directory

I belive you can use

rm -v !(filename)

Except for the filename all the other files will e deleted in the directory and make sure you are using it in

Permanently adding a file path to sys.path in Python

There are a few ways. One of the simplest is to create a my-paths.pth file (as described here). This is just a file with the extension .pth that you put into your system site-packages directory. On each line of the file you put one directory name, so you can put a line in there with /path/to/the/ and it will add that directory to the path.

You could also use the PYTHONPATH environment variable, which is like the system PATH variable but contains directories that will be added to sys.path. See the documentation.

Note that no matter what you do, sys.path contains directories not files. You can't "add a file to sys.path". You always add its directory and then you can import the file.

SQL: Return "true" if list of records exists?

If the IN clause is a parameter (either to SP or hot-built SQL), then this can always be done:

SELECT (SELECT COUNT(1)
          FROM product_a
         WHERE product_id IN (1, 8, 100)
       ) = (number of commas in product_id as constant)

If the IN clause is a table, then this can always be done:

SELECT (SELECT COUNT(*)
          FROM product_a
         WHERE product_id IN (SELECT Products
                                FROM #WorkTable)
       ) = (SELECT COUNT(*)
              FROM #WorkTable)

If the IN clause is complex then either spool it into a table or write it twice.

Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?

Doesn't matter if Connection is poolable or not. Even poolable connection has to clean before returning to the pool.

"Clean" usually means closing resultsets & rolling back any pending transactions but not closing the connection. Otherwise pooling looses its sense.

Custom Adapter for List View

This code is easy to understand.

three_horizontal_text_views_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/leftTextView"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/centreTextView"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/rightTextView"/>

</LinearLayout>

ThreeStrings.java

public class ThreeStrings {
    private String left;
    private String right;
    private String centre;

    public ThreeStrings(String left, String right, String centre) {
        this.left = left;
        this.right = right;
        this.centre = centre;
    }
}

ThreeHorizontalTextViewsAdapter.java

public class ThreeHorizontalTextViewsAdapter extends ArrayAdapter<ThreeStrings> {

private int layoutResource;

public ThreeHorizontalTextViewsAdapter(Context context, int layoutResource, List<ThreeStrings> threeStringsList) {
    super(context, layoutResource, threeStringsList);
    this.layoutResource = layoutResource;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View view = convertView;

    if (view == null) {
        LayoutInflater layoutInflater = LayoutInflater.from(getContext());
        view = layoutInflater.inflate(layoutResource, null);
    }

    ThreeStrings threeStrings = getItem(position);

    if (threeStrings != null) {
        TextView leftTextView = (TextView) view.findViewById(R.id.leftTextView);
        TextView rightTextView = (TextView) view.findViewById(R.id.rightTextView);
        TextView centreTextView = (TextView) view.findViewById(R.id.centreTextView);

        if (leftTextView != null) {
            leftTextView.setText(threeStrings.getLeft());
        }
        if (rightTextView != null) {
            rightTextView.setText(threeStrings.getRight());
        }
        if (centreTextView != null) {
            centreTextView.setText(threeStrings.getCentre());
        }
    }

    return view;
}
      }

main_layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context="com.androidapplication.ListActivity">


    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/listView"></ListView>

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        List<ThreeStrings> threeStringsList = new ArrayList<>();
        ThreeStrings threeStrings = new ThreeStrings("a", "b", "c");
        threeStringsList.add(threeStrings);        
        ListView listView = (ListView)findViewById(R.id.listView);
        ThreeHorizontalTextViewsAdapter threeHorizontalTextViewsAdapter = new ThreeHorizontalTextViewsAdapter(this, R.layout.three_horizontal_text_views_layout, threeStringsList);
        listView.setAdapter(threeHorizontalTextViewsAdapter);
      }
   //......}

Oracle SELECT TOP 10 records

You'll need to put your current query in subquery as below :

SELECT * FROM (
  SELECT DISTINCT 
  APP_ID, 
  NAME, 
  STORAGE_GB, 
  HISTORY_CREATED, 
  TO_CHAR(HISTORY_DATE, 'DD.MM.YYYY') AS HISTORY_DATE  
  FROM HISTORY WHERE 
    STORAGE_GB IS NOT NULL AND 
      APP_ID NOT IN (SELECT APP_ID FROM HISTORY WHERE TO_CHAR(HISTORY_DATE, 'DD.MM.YYYY') ='06.02.2009')
  ORDER BY STORAGE_GB DESC )
WHERE ROWNUM <= 10

Oracle applies rownum to the result after it has been returned.
You need to filter the result after it has been returned, so a subquery is required. You can also use RANK() function to get Top-N results.

For performance try using NOT EXISTS in place of NOT IN. See this for more.

Check date between two other dates spring data jpa

Maybe you could try

List<Article> findAllByPublicationDate(Date publicationDate);

The detail could be checked in this article:

https://www.baeldung.com/spring-data-jpa-query-by-date

Foreach in a Foreach in MVC View

Try this:

It looks like you are looping for every product each time, now this is looping for each product that has the same category ID as the current category being looped

<div id="accordion1" style="text-align:justify">
@using (Html.BeginForm())
{
    foreach (var category in Model.Categories)
    {
        <h3><u>@category.Name</u></h3>

        <div>
            <ul>    
                @foreach (var product in Model.Product.Where(m=> m.CategoryID= category.CategoryID)
                {
                    <li>
                        @product.Title
                        @if (System.Web.Security.UrlAuthorizationModule.CheckUrlAccessForPrincipal("/admin", User, "GET"))
                        {
                            @Html.Raw(" - ")  
                            @Html.ActionLink("Edit", "Edit", new { id = product.ID })
                        }
                        <ul>
                            <li>
                                @product.Description
                            </li>
                        </ul>
                    </li>
                }
            </ul>
        </div>
    }
}

How to force Laravel Project to use HTTPS for all routes?

Add this to your .htaccess code

RewriteEngine On 
RewriteCond %{SERVER_PORT} 80 
RewriteRule ^(.*)$ https://www.yourdomain.com/$1 [R,L]

Replace www.yourdomain.com with your domain name. This will force all the urls of your domain to use https. Make sure you have https certificate installed and configured on your domain. If you do not see https in green as secure, press f12 on chrome and fix all the mixed errors in the console tab.

Hope this helps!

Incrementing in C++ - When to use x++ or ++x?

The most important thing to keep in mind, imo, is that x++ needs to return the value before the increment actually took place -- therefore, it has to make a temporary copy of the object (pre increment). This is less effecient than ++x, which is incremented in-place and returned.

Another thing worth mentioning, though, is that most compilers will be able to optimize such unnecessary things away when possible, for instance both options will lead to same code here:

for (int i(0);i<10;++i)
for (int i(0);i<10;i++)

ERROR: Error 1005: Can't create table (errno: 121)

You can login to mysql and type

mysql> SHOW INNODB STATUS\G

You will have all the output and you should have a better idea of what the error is.

Dead simple example of using Multiprocessing Queue, Pool and Locking

The best solution for your problem is to utilize a Pool. Using Queues and having a separate "queue feeding" functionality is probably overkill.

Here's a slightly rearranged version of your program, this time with only 2 processes coralled in a Pool. I believe it's the easiest way to go, with minimal changes to original code:

import multiprocessing
import time

data = (
    ['a', '2'], ['b', '4'], ['c', '6'], ['d', '8'],
    ['e', '1'], ['f', '3'], ['g', '5'], ['h', '7']
)

def mp_worker((inputs, the_time)):
    print " Processs %s\tWaiting %s seconds" % (inputs, the_time)
    time.sleep(int(the_time))
    print " Process %s\tDONE" % inputs

def mp_handler():
    p = multiprocessing.Pool(2)
    p.map(mp_worker, data)

if __name__ == '__main__':
    mp_handler()

Note that mp_worker() function now accepts a single argument (a tuple of the two previous arguments) because the map() function chunks up your input data into sublists, each sublist given as a single argument to your worker function.

Output:

Processs a  Waiting 2 seconds
Processs b  Waiting 4 seconds
Process a   DONE
Processs c  Waiting 6 seconds
Process b   DONE
Processs d  Waiting 8 seconds
Process c   DONE
Processs e  Waiting 1 seconds
Process e   DONE
Processs f  Waiting 3 seconds
Process d   DONE
Processs g  Waiting 5 seconds
Process f   DONE
Processs h  Waiting 7 seconds
Process g   DONE
Process h   DONE

Edit as per @Thales comment below:

If you want "a lock for each pool limit" so that your processes run in tandem pairs, ala:

A waiting B waiting | A done , B done | C waiting , D waiting | C done, D done | ...

then change the handler function to launch pools (of 2 processes) for each pair of data:

def mp_handler():
    subdata = zip(data[0::2], data[1::2])
    for task1, task2 in subdata:
        p = multiprocessing.Pool(2)
        p.map(mp_worker, (task1, task2))

Now your output is:

 Processs a Waiting 2 seconds
 Processs b Waiting 4 seconds
 Process a  DONE
 Process b  DONE
 Processs c Waiting 6 seconds
 Processs d Waiting 8 seconds
 Process c  DONE
 Process d  DONE
 Processs e Waiting 1 seconds
 Processs f Waiting 3 seconds
 Process e  DONE
 Process f  DONE
 Processs g Waiting 5 seconds
 Processs h Waiting 7 seconds
 Process g  DONE
 Process h  DONE

jQuery datepicker, onSelect won't work

I have downloaded the datepicker from jqueryui.com/download and I got 1.7.2 version but still onSelect function didn't work. Here is what i had -

$("#datepicker").datepicker();

$("#datepicker").datepicker({ 
      onSelect: function(value, date) { 
         alert('The chosen date is ' + value); 
      } 
});

I found the solution in this page -- problem with jquery datepicker onselect . Removed the $("#datepicker").datepicker(); once and it worked.

How can I increase the JVM memory?

Right click on project -> Run As -> Run Configurations..-> Select Arguments tab -> In VM Arguments you can increase your JVM memory allocation. Java HotSpot document will help you to setup your VM Argument HERE

I will not prefer to make any changes into eclipse.ini as minor mistake cause lot of issues. It's easier to play with VM Args

Extract Number from String in Python

My answer does not require any additional libraries, and it's easy to understand. But you have to notice that if there's more than one number inside a string, my code will concatenate them together.

def search_number_string(string):
    index_list = []
    del index_list[:]
    for i, x in enumerate(string):
        if x.isdigit() == True:
            index_list.append(i)
    start = index_list[0]
    end = index_list[-1] + 1
    number = string[start:end]
    return number

Load Image from javascript

If you are loading the image via AJAX you could use a callback to check if the image is loaded and do the hiding and src attribute assigning. Something like this:

$.ajax({ 
  url: [image source],
  success: function() {
  // Do the hiding here and the attribute setting
  }
});

For more reading refer to this JQuery AJAX

MongoDb query condition on comparing 2 fields

In case performance is more important than readability and as long as your condition consists of simple arithmetic operations, you can use aggregation pipeline. First, use $project to calculate the left hand side of the condition (take all fields to left hand side). Then use $match to compare with a constant and filter. This way you avoid javascript execution. Below is my test in python:

import pymongo
from random import randrange

docs = [{'Grade1': randrange(10), 'Grade2': randrange(10)} for __ in range(100000)]

coll = pymongo.MongoClient().test_db.grades
coll.insert_many(docs)

Using aggregate:

%timeit -n1 -r1 list(coll.aggregate([
    {
        '$project': {
            'diff': {'$subtract': ['$Grade1', '$Grade2']},
            'Grade1': 1,
            'Grade2': 1
        }
    },
    {
        '$match': {'diff': {'$gt': 0}}
    }
]))

1 loop, best of 1: 192 ms per loop

Using find and $where:

%timeit -n1 -r1 list(coll.find({'$where': 'this.Grade1 > this.Grade2'}))

1 loop, best of 1: 4.54 s per loop

What does java.lang.Thread.interrupt() do?

If the targeted thread has been waiting (by calling wait(), or some other related methods that essentially do the same thing, such as sleep()), it will be interrupted, meaning that it stops waiting for what it was waiting for and receive an InterruptedException instead.

It is completely up to the thread itself (the code that called wait()) to decide what to do in this situation. It does not automatically terminate the thread.

It is sometimes used in combination with a termination flag. When interrupted, the thread could check this flag, and then shut itself down. But again, this is just a convention.

Why is "1000000000000000 in range(1000000000000001)" so fast in Python 3?

TLDR; range is an arithmetic series so it can very easily calculate whether the object is there.It could even get the index of it if it were list like really quickly.

Generating a unique machine id

In my program I first check for Terminal Server and use the WTSClientHardwareId. Else the MAC address of the local PC should be adequate.

If you really want to use the list of properties you provided leave out things like Name and DriverVersion, Clockspeed, etc. since it's possibly OS dependent. Try outputting the same info on both operating systems and leave out that which differs between.

How to get IntPtr from byte[] in C#

Another way,

GCHandle pinnedArray = GCHandle.Alloc(byteArray, GCHandleType.Pinned);
IntPtr pointer = pinnedArray.AddrOfPinnedObject();
// Do your stuff...
pinnedArray.Free();

JUNIT Test class in Eclipse - java.lang.ClassNotFoundException

I add this answer as my solution review from the above.

You simply edit the file .project in the main project folder. Use a proper XML Editor otherwise you will get a fatal error from Eclipse that stats you can not open this project.
I made my project nature Javaby adding this <nature>org.eclipse.jdt.core.javanature</nature> to <natures></natures>.
I then added those lines correctly indented <buildCommand><name>org.eclipse.jdt.core.javabuilder</name><arguments></arguments></buildCommand> to <buildSpec></buildSpec>.
Run as JUnit ... Success

Is there a standardized method to swap two variables in Python?

You can combine tuple and XOR swaps: x, y = x ^ x ^ y, x ^ y ^ y

x, y = 10, 20

print('Before swapping: x = %s, y = %s '%(x,y))

x, y = x ^ x ^ y, x ^ y ^ y

print('After swapping: x = %s, y = %s '%(x,y))

x, y = 10, 20

print('Before swapping: x = %s, y = %s '%(x,y))

print('After swapping: x = %s, y = %s '%(x ^ x ^ y, x ^ y ^ y))

Using lambda:

x, y = 10, 20

print('Before swapping: x = %s, y = %s' % (x, y))

swapper = lambda x, y : ((x ^ x ^ y), (x ^ y ^ y))

print('After swapping: x = %s, y = %s ' % swapper(x, y))

Output:

Before swapping: x =  10 , y =  20
After swapping: x =  20 , y =  10

How do I get current date/time on the Windows command line in a suitable format for usage in a file/folder name?

I know that there are numerous ways mentioned already. But here is my way to break it down to understand how it is done. Hopefully, it is helpful for someone who like step by step method.

:: Check your local date format
echo %date%

    :: Output is Mon 08/15/2016

:: get day (start index, number of characters)
::         (index starts with zero)
set myday=%DATE:~0,4%
echo %myday%
    :: output is Mon 

:: get month
set mymonth=%DATE:~4,2%
echo %mymonth%
    :: output is 08

:: get date 
set mydate=%DATE:~7,2% 
echo %mydate%
    :: output is 15

:: get year
set myyear=%DATE:~10,4%
echo %myyear%
    :: output is 2016

Find largest and smallest number in an array

Unless you really must implement your own solution, you can use std::minmax_element. This returns a pair of iterators, one to the smallest element and one to the largest.

#include <algorithm>

auto minmax = std::minmax_element(std::begin(values), std::end(values));

std::cout << "min element " << *(minmax.first) << "\n";
std::cout << "max element " << *(minmax.second) << "\n";

FirstOrDefault returns NullReferenceException if no match is found

To add to the solutions, here is a LINQ statement that might help

Utilities.DIMENSION_MemTbl.Where(a => a.DIMENSION_ID == format.ContentBrief.DimensionID).Select(a=>a.DIMENSION1).DefaultIfEmpty("").FirstOrDefault();

The result will be an empty string if the result of the query is a null..

How to label each equation in align environment?

Usually my align environments are set up like

\begin{align} 
  \label{eqn1}
  \lambda_i + \mu_i = 0 \\
  \label{eqn2}
  \mu_i \xi_i = 0 \\
  \label{eqn3}
  \lambda_i [y_i( w^T x_i + b) - 1 + \xi_i] = 0
\end{align}

The \label command should be placed in the line you want to reference, the placement in the line does not matter. I prefer to place it at the beginning at the line (as a sort of description) while others place them at the end.

Solving a "communications link failure" with JDBC and MySQL

For Windows :- Goto start menu write , "MySqlserver Instance Configuration Wizard" and reconfigure your mysql server instance. Hope it will solve your problem.

Are nested try/except blocks in Python a good programming practice?

I like to avoid raising a new exception while handling an old one. It makes the error messages confusing to read.

For example, in my code, I originally wrote

try:
    return tuple.__getitem__(self, i)(key)
except IndexError:
    raise KeyError(key)

And I got this message.

>>> During handling of above exception, another exception occurred.

I wanted this:

try:
    return tuple.__getitem__(self, i)(key)
except IndexError:
    pass
raise KeyError(key)

It doesn't affect how exceptions are handled. In either block of code, a KeyError would have been caught. This is merely an issue of getting style points.

Convert between UIImage and Base64 string

Swift 4.2 Extension method

extension UIImage {
    func toBase64() -> String? {
        guard let imageData = self.pngData() else { return nil }
        return imageData.base64EncodedString(options: Data.Base64EncodingOptions.lineLength64Characters)
    }
}

XCode 9.1 and Swift 4.0

//
// Convert UIImage to a base64 representation
//
class func convertImageToBase64(image: UIImage) -> String {
    let imageData = UIImagePNGRepresentation(image)!
    return imageData.base64EncodedString(options: Data.Base64EncodingOptions.lineLength64Characters)
}

//
// Convert a base64 representation to a UIImage
//
class func convertBase64ToImage(imageString: String) -> UIImage {
    let imageData = Data(base64Encoded: imageString, options: Data.Base64DecodingOptions.ignoreUnknownCharacters)!
    return UIImage(data: imageData)!
}

How do I specify the columns and rows of a multiline Editor-For in ASP.MVC?

@Html.TextArea("txtNotes", "", 4, 0, new { @class = "k-textbox", style = "width: 100%; height: 100%;" })

Making a triangle shape using xml definitions?

I provide this customView below if you don't want to hack xml. Please have a try.

/**
 * TriangleView
 *
 * @author Veer
 * @date 2020-09-03
 */
class TriangleView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {
    private var triangleColor: Int = 0
    private var direction = Direction.Bottom

    private val paint by lazy {
        Paint().apply {
            isAntiAlias = true
            style = Paint.Style.FILL
            color = triangleColor
        }
    }

    init {
        initStyle(context, attrs, defStyleAttr)
    }

    private fun initStyle(
        context: Context,
        attrs: AttributeSet?,
        defStyleAttr: Int
    ) {
        val ta = context.obtainStyledAttributes(attrs, R.styleable.TriangleView, defStyleAttr, 0)
        with(ta) {
            triangleColor =
                getColor(R.styleable.TriangleView_triangle_background, Color.parseColor("#000000"))

            val directionValue =
                getInt(R.styleable.TriangleView_triangle_direction, Direction.Bottom.value)
            direction = when (directionValue) {
                Direction.Top.value -> Direction.Top
                Direction.Bottom.value -> Direction.Bottom
                Direction.Left.value -> Direction.Left
                Direction.Right.value -> Direction.Right
                else -> Direction.Bottom
            }

            recycle()
        }
    }

    override fun onDraw(canvas: Canvas) {
        calculatePath(direction).let {
            canvas.drawPath(it, paint)
        }
    }

    private fun calculatePath(direction: Direction): Path {
        var p1: Point? = null
        var p2: Point? = null
        var p3: Point? = null

        val width = width
        val height = height

        when (direction) {
            Direction.Top -> {
                p1 = Point(0, height)
                p2 = Point(width / 2, 0)
                p3 = Point(width, height)
            }
            Direction.Bottom -> {
                p1 = Point(0, 0)
                p2 = Point(width / 2, height)
                p3 = Point(width, 0)
            }
            Direction.Left -> {
                p1 = Point(width, 0)
                p2 = Point(0, height / 2)
                p3 = Point(width, height)
            }
            Direction.Right -> {
                p1 = Point(0, 0)
                p2 = Point(width, height / 2)
                p3 = Point(0, height)
            }
        }

        val path = Path()
        path.moveTo(p1.x.toFloat(), p1.y.toFloat())
        path.lineTo(p2.x.toFloat(), p2.y.toFloat())
        path.lineTo(p3.x.toFloat(), p3.y.toFloat())
        return path
    }

    private enum class Direction(val value: Int) {
        Top(0),
        Bottom(1),
        Left(2),
        Right(3)
    }
}

<declare-styleable name="TriangleView">
    <attr name="triangle_direction" format="enum">
        <enum name="top" value="0" />
        <enum name="bottom" value="1" />
        <enum name="left" value="2" />
        <enum name="right" value="3" />
    </attr>
    <attr name="triangle_background" format="reference|color" />
</declare-styleable>

How do I schedule a task to run at periodic intervals?

Use timer.scheduleAtFixedRate

public void scheduleAtFixedRate(TimerTask task,
                                long delay,
                                long period)

Schedules the specified task for repeated fixed-rate execution, beginning after the specified delay. Subsequent executions take place at approximately regular intervals, separated by the specified period.
In fixed-rate execution, each execution is scheduled relative to the scheduled execution time of the initial execution. If an execution is delayed for any reason (such as garbage collection or other background activity), two or more executions will occur in rapid succession to "catch up." In the long run, the frequency of execution will be exactly the reciprocal of the specified period (assuming the system clock underlying Object.wait(long) is accurate).

Fixed-rate execution is appropriate for recurring activities that are sensitive to absolute time, such as ringing a chime every hour on the hour, or running scheduled maintenance every day at a particular time. It is also appropriate for recurring activities where the total time to perform a fixed number of executions is important, such as a countdown timer that ticks once every second for ten seconds. Finally, fixed-rate execution is appropriate for scheduling multiple repeating timer tasks that must remain synchronized with respect to one another.

Parameters:

task - task to be scheduled.
delay - delay in milliseconds before task is to be executed.
period - time in milliseconds between successive task executions.

Throws:

IllegalArgumentException - if delay is negative, or delay + System.currentTimeMillis() is negative.
IllegalStateException - if task was already scheduled or cancelled, timer was cancelled, or timer thread terminated.

Include in SELECT a column that isn't actually in the database

You may want to use:

SELECT Name, 'Unpaid' AS Status FROM table;

The SELECT clause syntax, as defined in MSDN: SELECT Clause (Transact-SQL), is as follows:

SELECT [ ALL | DISTINCT ]
[ TOP ( expression ) [ PERCENT ] [ WITH TIES ] ] 
<select_list>

Where the expression can be a constant, function, any combination of column names, constants, and functions connected by an operator or operators, or a subquery.

Python Pandas counting and summing specific conditions

You didn't mention the fancy indexing capabilities of dataframes, e.g.:

>>> df = pd.DataFrame({"class":[1,1,1,2,2], "value":[1,2,3,4,5]})
>>> df[df["class"]==1].sum()
class    3
value    6
dtype: int64
>>> df[df["class"]==1].sum()["value"]
6
>>> df[df["class"]==1].count()["value"]
3

You could replace df["class"]==1by another condition.

What port is a given program using?

If your prefer a GUI interface CurrPorts is free and works with all versions of windows. Shows ports and what process has them open.

How to upgrade Git on Windows to the latest version?

Since Git 2.16.1(2) you can use

C:\> git update-git-for-windows

In version between 2.14.2 and 2.16.1, the command was

C:\> git update

(It was later renamed to avoid confusion with updating the local repository, e.g. like svn update does it.)

That command does not exist in Git 2.13 and before.

If this errors with "is not a git command" then either you don't actually have Git for Windows, or your version is very old.

In which case, simply get the latest installer from https://git-scm.com/download (check whether you want 32- or 64-bit) and run it to upgrade.

If you already have the latest version it does nothing, in which case you can manually run the installer to reinstall.

C:\> git update-git-for-windows
Git for Windows 2.17.0.windows.1 (64bit)
Up to date

Get value of a specific object property in C# without knowing the class behind

You can do it using dynamic instead of object:

dynamic item = AnyFunction(....);
string value = item.name;

Note that the Dynamic Language Runtime (DLR) has built-in caching mechanisms, so subsequent calls are very fast.

load scripts asynchronously

I loaded the scripts asynchronously (html 5 has that feature) when all the scripts where done loading I redirected the page to index2.html where index2.html uses the same libraries. Because browsers have a cache once the page redirects to index2.html, index2.html loads in less than a second because it has all it needs to load the page. In my index.html page I also load the images that I plan on using so that the browser place those images on the cache. so my index.html looks like:

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
    <title>Project Management</title>

    <!-- the purpose of this page is to load all the scripts on the browsers cache so that pages can load fast from now on -->

    <script type="text/javascript">

        function stylesheet(url) {
            var s = document.createElement('link');
            s.type = 'text/css';
            s.async = true;
            s.src = url;
            var x = document.getElementsByTagName('head')[0];
            x.appendChild(s);
        }

        function script(url) {
            var s = document.createElement('script');
            s.type = 'text/javascript';
            s.async = true;
            s.src = url;
            var x = document.getElementsByTagName('head')[0];
            x.appendChild(s);
        }

        //load scritps to the catche of browser
        (function () {            
                stylesheet('css/custom-theme/jquery-ui-1.8.16.custom.css');
                stylesheet('css/main.css');
                stylesheet('css/marquee.css');
                stylesheet('css/mainTable.css');

                script('js/jquery-ui-1.8.16.custom.min.js');
                script('js/jquery-1.6.2.min.js');
                script('js/myFunctions.js');
                script('js/farinspace/jquery.imgpreload.min.js');
                script('js/marquee.js');            
        })();

    </script>

    <script type="text/javascript">
       // once the page is loaded go to index2.html
        window.onload = function () {
            document.location = "index2.html";
        }
    </script>

</head>
<body>

<div id="cover" style="position:fixed; left:0px; top:0px; width:100%; height:100%; background-color:Black; z-index:100;">Loading</div>

<img src="images/home/background.png" />
<img src="images/home/3.png"/>
<img src="images/home/6.jpg"/>
<img src="images/home/4.png"/>
<img src="images/home/5.png"/>
<img src="images/home/8.jpg"/>
<img src="images/home/9.jpg"/>
<img src="images/logo.png"/>
<img src="images/logo.png"/>
<img src="images/theme/contentBorder.png"/>

</body>
</html>

another nice thing about this is that I may place a loader in the page and when the page is done loading the loader will go away and in a matte of milliseconds the new page will be running.

ConvergenceWarning: Liblinear failed to converge, increase the number of iterations

Normally when an optimization algorithm does not converge, it is usually because the problem is not well-conditioned, perhaps due to a poor scaling of the decision variables. There are a few things you can try.

Normalize your training data so that the problem hopefully becomes more well conditioned, which in turn can speed up convergence. One possibility is to scale your data to 0 mean, unit standard deviation using Scikit-Learn's StandardScaler for an example. Note that you have to apply the StandardScaler fitted on the training data to the test data.
Related to 1), make sure the other arguments such as regularization weight, C, is set appropriately.
Set max_iter to a larger value. The default is 1000.
Set dual = True if number of features > number of examples and vice versa. This solves the SVM optimization problem using the dual formulation. Thanks @Nino van Hooff for pointing this out, and @JamesKo for spotting my mistake.
Use a different solver, for e.g., the L-BFGS solver if you are using Logistic Regression. See @5ervant's answer.

Note: One should not ignore this warning.

This warning came about because

Solving the linear SVM is just solving a quadratic optimization problem. The solver is typically an iterative algorithm that keeps a running estimate of the solution (i.e., the weight and bias for the SVM). It stops running when the solution corresponds to an objective value that is optimal for this convex optimization problem, or when it hits the maximum number of iterations set.
If the algorithm does not converge, then the current estimate of the SVM's parameters are not guaranteed to be any good, hence the predictions can also be complete garbage.

Edit

In addition, consider the comment by @Nino van Hooff and @5ervant to use the dual formulation of the SVM. This is especially important if the number of features you have, D, is more than the number of training examples N. This is what the dual formulation of the SVM is particular designed for and helps with the conditioning of the optimization problem. Credit to @5ervant for noticing and pointing this out.

Furthermore, @5ervant also pointed out the possibility of changing the solver, in particular the use of the L-BFGS solver. Credit to him (i.e., upvote his answer, not mine).

I would like to provide a quick rough explanation for those who are interested (I am :)) why this matters in this case. Second-order methods, and in particular approximate second-order method like the L-BFGS solver, will help with ill-conditioned problems because it is approximating the Hessian at each iteration and using it to scale the gradient direction. This allows it to get better convergence rate but possibly at a higher compute cost per iteration. That is, it takes fewer iterations to finish but each iteration will be slower than a typical first-order method like gradient-descent or its variants.

For e.g., a typical first-order method might update the solution at each iteration like

x(k + 1) = x(k) - alpha(k) * gradient(f(x(k)))

where alpha(k), the step size at iteration k, depends on the particular choice of algorithm or learning rate schedule.

A second order method, for e.g., Newton, will have an update equation

x(k + 1) = x(k) - alpha(k) * Hessian(x(k))^(-1) * gradient(f(x(k)))

That is, it uses the information of the local curvature encoded in the Hessian to scale the gradient accordingly. If the problem is ill-conditioned, the gradient will be pointing in less than ideal directions and the inverse Hessian scaling will help correct this.

In particular, L-BFGS mentioned in @5ervant's answer is a way to approximate the inverse of the Hessian as computing it can be an expensive operation.

However, second-order methods might converge much faster (i.e., requires fewer iterations) than first-order methods like the usual gradient-descent based solvers, which as you guys know by now sometimes fail to even converge. This can compensate for the time spent at each iteration.

In summary, if you have a well-conditioned problem, or if you can make it well-conditioned through other means such as using regularization and/or feature scaling and/or making sure you have more examples than features, you probably don't have to use a second-order method. But these days with many models optimizing non-convex problems (e.g., those in DL models), second order methods such as L-BFGS methods plays a different role there and there are evidence to suggest they can sometimes find better solutions compared to first-order methods. But that is another story.

How do you test to see if a double is equal to NaN?

Beginners needs practical examples. so try the following code.

public class Not_a_Number {

public static void main(String[] args) {
    // TODO Auto-generated method stub

    String message = "0.0/0.0 is NaN.\nsimilarly Math.sqrt(-1) is NaN.";        
    String dottedLine = "------------------------------------------------";     

    Double numerator = -2.0;
    Double denominator = -2.0;      
    while (denominator <= 1) {
        Double x = numerator/denominator;           
        Double y = new Double (x);
        boolean z = y.isNaN();
        System.out.println("y =  " + y);
        System.out.println("z =  " + z);
        if (z == true){
            System.out.println(message);                
        }
        else {
            System.out.println("Hi, everyone"); 
        }
        numerator = numerator + 1;
        denominator = denominator +1;
        System.out.println(dottedLine);         
    } // end of while

} // end of main

} // end of class

Access Denied for User 'root'@'localhost' (using password: YES) - No Privileges?

I don't think you have to escape the --init-file parameter:

"C:\Program Files\MySQL\MySQL Server 5.6\bin\mysqld.exe" --defaults-file="C:\\Program Files\\MySQL\\MySQL Server 5.6\\my.ini" --init-file=C:\\mysql-init.txt

Should be:

"C:\Program Files\MySQL\MySQL Server 5.6\bin\mysqld.exe" --defaults-file="C:\\Program Files\\MySQL\\MySQL Server 5.6\\my.ini" --init-file=C:\mysql-init.txt

Apache2: 'AH01630: client denied by server configuration'

In case this helps anyone Googling around like I was, I had this error message trying to access a SVG file on my server, e.g. https://example.com/images/file.svg. Other file types seemed fine, just SVG were failing.

I hunted around /etc/httpd conf files and checked every require all denied type of configuration, and just could not find what config was having this effect.

I turned LogLevel to debug in the VirtualHost config and could see the mod_authz_core logging specifying there was a 'Require all denied' in effect:

[Mon Jun 10 13:09:54.321022 2019] [authz_core:debug] [pid 23459:tid 140576341206784] mod_authz_core.c(817): [client 127.0.0.1:54626] AH01626: authorization result of Require all denied: denied
[Mon Jun 10 13:09:54.321038 2019] [authz_core:debug] [pid 23459:tid 140576341206784] mod_authz_core.c(817): [client 127.0.0.1:54626] AH01626: authorization result of <RequireAny>: denied
[Mon Jun 10 13:09:54.321082 2019] [authz_core:error] [pid 23459:tid 140576341206784] [client 127.0.0.1:54626] AH01630: client denied by server configuration: /home/blah/htdocs/images/file.svg

Through blind testing I moved the file to the root of the web root, and found I could then access it at https://example.com/file.svg .. so it only failed in the 'images' folder. This led me to an .htaccess file in the images folder that I had no idea was there.

Turns out Zen Cart 1.5 comes with an images/.htaccess file that has:

# deny *everything*
 <FilesMatch ".*">
   <IfModule mod_authz_core.c>
     Require all denied
   </IfModule>
   <IfModule !mod_authz_core.c>
     Order Allow,Deny
     Deny from all
   </IfModule>
 </FilesMatch>

 # but now allow just *certain* necessary files:
 <FilesMatch "(?i).*\.(jpe?g|gif|webp|png|swf)$" >
   <IfModule mod_authz_core.c>
     Require all granted
   </IfModule>
   <IfModule !mod_authz_core.c>
     Order Allow,Deny
     Allow from all
   </IfModule>
 </FilesMatch>

This was very annoying and I hope this might remind others to check .htaccess files at every level of the file system leading to the file you're having trouble accessing in case there is this kind of tom foolery going on.

Spring transaction REQUIRED vs REQUIRES_NEW : Rollback Transaction

Using REQUIRES_NEW is only relevant when the method is invoked from a transactional context; when the method is invoked from a non-transactional context, it will behave exactly as REQUIRED - it will create a new transaction.

That does not mean that there will only be one single transaction for all your clients - each client will start from a non-transactional context, and as soon as the the request processing will hit a @Transactional, it will create a new transaction.

So, with that in mind, if using REQUIRES_NEW makes sense for the semantics of that operation - than I wouldn't worry about performance - this would textbook premature optimization - I would rather stress correctness and data integrity and worry about performance once performance metrics have been collected, and not before.

On rollback - using REQUIRES_NEW will force the start of a new transaction, and so an exception will rollback that transaction. If there is also another transaction that was executing as well - that will or will not be rolled back depending on if the exception bubbles up the stack or is caught - your choice, based on the specifics of the operations. Also, for a more in-depth discussion on transactional strategies and rollback, I would recommend: «Transaction strategies: Understanding transaction pitfalls», Mark Richards.

How to include external Python code to use in other files?

I've found the python inspect module to be very useful

For example with teststuff.py

import inspect

def dostuff():
    return __name__

DOSTUFF_SOURCE = inspect.getsource(dostuff)

if __name__ == "__main__":

    dostuff()

And from the another script or the python console

import teststuff

exec(DOSTUFF_SOURCE)

dostuff()

And now dostuff should be in the local scope and dostuff() will return the console or scripts _name_ whereas executing test.dostuff() will return the python modules name.

create a trusted self-signed SSL cert for localhost (for use with Express/Node)

There are more aspects to this.

You can achieve TLS (some keep saying SSL) with a certificate, self-signed or not.

To have a green bar for a self-signed certificate, you also need to become the Certificate Authority (CA). This aspect is missing in most resources I found on my journey to achieve the green bar in my local development setup. Becoming a CA is as easy as creating a certificate.

This resource covers the creation of both the CA certificate and a Server certificate and resulted my setup in showing a green bar on localhost Chrome, Firefox and Edge: https://ram.k0a1a.net/self-signed_https_cert_after_chrome_58

Please note: in Chrome you need to add the CA Certificate to your trusted authorities.

Best way to add Activity to an Android project in Eclipse?

I have create a eclipse plugin to create activity in one click .

Just download the Plugin from https://docs.google.com/file/d/0B63U_IjxUP_GMkdYZzc1Y3lEM1U/edit?usp=sharing

Paste the plugin in the dropins folder in Eclipse and restart eclipse

For more details please see my blog
http://shareatramachandran.blogspot.in/2013/06/android-activity-plugin-for-eclispe.html

Need your comment on this if it was helpful...

Child element click event trigger the parent click event

The stopPropagation() method stops the bubbling of an event to parent elements, preventing any parent handlers from being notified of the event.

You can use the method event.isPropagationStopped() to know whether this method was ever called (on that event object).

Syntax:

Here is the simple syntax to use this method:

event.stopPropagation()

Example:

$("div").click(function(event) {
    alert("This is : " + $(this).prop('id'));

    // Comment the following to see the difference
    event.stopPropagation();
});?

Windows command to convert Unix line endings?

Based on Endoro's answer but to keep the blanks, try this:

@echo off
setlocal enabledelayedexpansion
(for /f "tokens=* delims=:" %%i in ('findstr /n "^" file.unix') do (
        set line=%%i
        set line=!line:*:=!
        echo(!line!
        ))>file.dos

How to properly use the "choices" field option in Django

I think no one actually has answered to the first question:

Why did they create those variables?

Those variables aren't strictly necessary. It's true. You can perfectly do something like this:

MONTH_CHOICES = (
    ("JANUARY", "January"),
    ("FEBRUARY", "February"),
    ("MARCH", "March"),
    # ....
    ("DECEMBER", "December"),
)

month = models.CharField(max_length=9,
                  choices=MONTH_CHOICES,
                  default="JANUARY")

Why using variables is better? Error prevention and logic separation.

JAN = "JANUARY"
FEB = "FEBRUARY"
MAR = "MAR"
# (...)

MONTH_CHOICES = (
    (JAN, "January"),
    (FEB, "February"),
    (MAR, "March"),
    # ....
    (DEC, "December"),
)

Now, imagine you have a view where you create a new Model instance. Instead of doing this:

new_instance = MyModel(month='JANUARY')

You'll do this:

new_instance = MyModel(month=MyModel.JAN)

In the first option you are hardcoding the value. If there is a set of values you can input, you should limit those options when coding. Also, if you eventually need to change the code at the Model layer, now you don't need to make any change in the Views layer.

Typescript input onchange event.target.value

Here is a way with ES6 object destructuring, tested with TS 3.3.
This example is for a text input.

name: string = '';

private updateName({ target }: { target: HTMLInputElement }) {
    this.name = target.value;
}

Activity has leaked window that was originally added

Got this error when trying to display a Toast from Background thread. It was solved by running the UI related code on the UI thread

sys.path different in Jupyter and Python - how to import own modules in Jupyter?

Here is what I do on my projects in jupyter notebook,

import sys
sys.path.append("../") # go to parent dir
from customFunctions import *

Then, to affect changes in customFunctions.py,

%load_ext autoreload
%autoreload 2

How to Delete a topic in apache kafka

Deletion of a topic has been supported since 0.8.2.x version. You have to enable topic deletion (setting delete.topic.enable to true) on all brokers first.

Note: Ever since 1.0.x, the functionality being stable, delete.topic.enable is by default true.

Follow this step by step process for manual deletion of topics

Stop Kafka server
Delete the topic directory, on each broker (as defined in the logs.dirs and log.dir properties) with rm -rf command
Connect to Zookeeper instance: zookeeper-shell.sh host:port
From within the Zookeeper instance:
1. List the topics using: ls /brokers/topics
2. Remove the topic folder from ZooKeeper using: rmr /brokers/topics/yourtopic
3. Exit the Zookeeper instance (Ctrl+C)
Restart Kafka server
Confirm if it was deleted or not by using this command kafka-topics.sh --list --zookeeper host:port

Specifying trust store information in spring boot application.properties

I was also having the same issue with Spring Boot and embedded Tomcat.

From what I understand these properties only set the Tomcat configuration parameters. According to the Tomcat documentation this is only used for Client authentication (i.e. for two-way SSL) and not for verifying remote certificates:

truststoreFile - The trust store file to use to validate client certificates.

https://tomcat.apache.org/tomcat-8.0-doc/config/http.html

In order to configure the trust store for HttpClient it largely depends on the HttpClient implementation you use. For instance for RestTemplate by default Spring Boot uses a SimpleClientHttpRequestFactory based on standard J2SE classes like java.net.HttpURLConnection.

I've come up with a solution based on the Apache HttpClient docs and these posts: http://vincentdevillers.blogspot.pt/2013/02/configure-best-spring-resttemplate.html http://literatejava.com/networks/ignore-ssl-certificate-errors-apache-httpclient-4-4/

Basically this allows for a RestTemplate bean that only trusts certificates signed by the root CA in the configured truststore.

@Configuration
public class RestClientConfig {

    // e.g. Add http.client.ssl.trust-store=classpath:ssl/truststore.jks to application.properties
    @Value("${http.client.ssl.trust-store}")
    private Resource trustStore;

    @Value("${http.client.ssl.trust-store-password}")
    private char[] trustStorePassword;

    @Value("${http.client.maxPoolSize}")
    private Integer maxPoolSize;


    @Bean
    public ClientHttpRequestFactory httpRequestFactory() {
        return new HttpComponentsClientHttpRequestFactory(httpClient());
    }

    @Bean
    public HttpClient httpClient() {

        // Trust own CA and all child certs
        Registry<ConnectionSocketFactory> socketFactoryRegistry = null;
        try {
            SSLContext sslContext = SSLContexts
                    .custom()
                    .loadTrustMaterial(trustStore.getFile(),
                            trustStorePassword)
                    .build();

            // Since only our own certs are trusted, hostname verification is probably safe to bypass
            SSLConnectionSocketFactory sslSocketFactory = new SSLConnectionSocketFactory(sslContext,
                    new HostnameVerifier() {

                        @Override
                        public boolean verify(final String hostname,
                                final SSLSession session) {
                            return true;
                        }
            });

            socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
                    .register("http", PlainConnectionSocketFactory.getSocketFactory())
                    .register("https", sslSocketFactory)
                    .build();           

        } catch (Exception e) {
            //TODO: handle exceptions
            e.printStackTrace();
        }

        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
        connectionManager.setMaxTotal(maxPoolSize);
        // This client is for internal connections so only one route is expected
        connectionManager.setDefaultMaxPerRoute(maxPoolSize);
        return HttpClientBuilder.create()
                .setConnectionManager(connectionManager)
                .disableCookieManagement()
                .disableAuthCaching()
                .build();
    }

    @Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate();
        restTemplate.setRequestFactory(httpRequestFactory());
        return restTemplate;
    }    
}

And then you can use this custom Rest client whenever you need to, e.g.:

@Autowired
private RestTemplate restTemplate;

restTemplate.getForEntity(...)

This assumes your trying to connect to a Rest endpoint, but you can also use the above HttpClient bean for whatever you want.

Add params to given URL in Python

I liked Lukasz version, but since urllib and urllparse functions are somewhat awkward to use in this case, I think it's more straightforward to do something like this:

params = urllib.urlencode(params)

if urlparse.urlparse(url)[4]:
    print url + '&' + params
else:
    print url + '?' + params

How to properly make a http web GET request

Simpliest way for my opinion

  var web = new WebClient();
  var url = $"{hostname}/LoadDataSync?systemID={systemId}";
  var responseString = web.DownloadString(url);

 var bytes = web.DownloadData(url);

Site does not exist error for a2ensite

I realise that's not the case here but it might help someone.

Double-check you didn't create the conf file in /etc/apache2/sites-enabled by mistake. You get the same error.

Get path to execution directory of Windows Forms application

Both of the examples are in VB.NET.

Debug path:

TextBox1.Text = My.Application.Info.DirectoryPath

EXE path:

TextBox2.Text = IO.Path.GetFullPath(Application.ExecutablePath)

SOAP vs REST (differences)

SOAP (Simple Object Access Protocol) and REST (Representation State Transfer) both are beautiful in their way. So I am not comparing them. Instead, I am trying to depict the picture, when I preferred to use REST and when SOAP.

What is payload?

When data is sent over the Internet, each unit transmitted includes both header information and the actual data being sent. The header identifies the source and destination of the packet, while the actual data is referred to as the payload. In general, the payload is the data that is carried on behalf of an application and the data received by the destination system.

Now, for example, I have to send a Telegram and we all know that the cost of the telegram will depend on some words.

So tell me among below mentioned these two messages, which one is cheaper to send?

<name>Arin</name>

"name": "Arin"

I know your answer will be the second one although both representing the same message second one is cheaper regarding cost.

So I am trying to say that, sending data over the network in JSON format is cheaper than sending it in XML format regarding payload.

Here is the first benefit or advantages of REST over SOAP. SOAP only support XML, but REST supports different format like text, JSON, XML, etc. And we already know, if we use Json then definitely we will be in better place regarding payload.

Now, SOAP supports the only XML, but it also has its advantages.

Really! How?

SOAP relies on XML in three ways Envelope – that defines what is in the message and how to process it.

A set of encoding rules for data types, and finally the layout of the procedure calls and responses gathered.

This envelope is sent via a transport (HTTP/HTTPS), and an RPC (Remote Procedure Call) is executed, and the envelope is returned with information in an XML formatted document.

The important point is that one of the advantages of SOAP is the use of the “generic” transport but REST uses HTTP/HTTPS. SOAP can use almost any transport to send the request but REST cannot. So here we got an advantage of using SOAP.

As I already mentioned in above paragraph “REST uses HTTP/HTTPS”, so go a bit deeper on these words.

When we are talking about REST over HTTP, all security measures applied HTTP are inherited, and this is known as transport level security and it secures messages only while it is inside the wire but once you delivered it on the other side you don’t know how many stages it will have to go through before reaching the real point where the data will be processed. And of course, all those stages could use something different than HTTP.So Rest is not safer completely, right?

But SOAP supports SSL just like REST additionally it also supports WS-Security which adds some enterprise security features. WS-Security offers protection from the creation of the message to it’s consumption. So for transport level security whatever loophole we found that can be prevented using WS-Security.

Apart from that, as REST is limited by it's HTTP protocol so it’s transaction support is neither ACID compliant nor can provide two-phase commit across distributed transnational resources.

But SOAP has comprehensive support for both ACID based transaction management for short-lived transactions and compensation based transaction management for long-running transactions. It also supports two-phase commit across distributed resources.

I am not drawing any conclusion, but I will prefer SOAP-based web service while security, transaction, etc. are the main concerns.

Here is the "The Java EE 6 Tutorial" where they have said A RESTful design may be appropriate when the following conditions are met. Have a look.

Hope you enjoyed reading my answer.

Logging with Retrofit 2

First Add dependency to build.gradle:

implementation 'com.squareup.okhttp3:logging-interceptor:3.12.1'

While using Kotlin you can add Logging Interceptor like this :

companion object {
    val okHttpClient = OkHttpClient().newBuilder()
            .addInterceptor(HttpLoggingInterceptor().apply {
                level = HttpLoggingInterceptor.Level.BODY
            })
            .build()


    fun getRetrofitInstance(): Retrofit {
        val retrofit = Retrofit.Builder()
                .client(okHttpClient)
                .baseUrl(ScanNShopConstants.BASE_URL)
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .addConverterFactory(GsonConverterFactory.create())
                .build()

        return retrofit
    }
}

Where can I find a NuGet package for upgrading to System.Web.Http v5.0.0.0?

I have several projects in a solution. For some of the projects, I previously added the references manually. When I used NuGet to update the WebAPI package, those references were not updated automatically.

I found out that I can either manually update those reference so they point to the v5 DLL inside the Packages folder of my solution or do the following.

Go to the "Manage NuGet Packages"
Select the Installed Package "Microsoft ASP.NET Web API 2.1"
Click Manage and check the projects that I manually added before.

NodeJs : TypeError: require(...) is not a function

For me, I got similar error when switched between branches - one used newer ("typescriptish") version of @google-cloud/datastore packages which returns object with Datastore constructor as one of properties of exported object and I switched to other branch for a task, an older datastore version was used there, which exports Datastore constructor "directly" as module.exports value. I got the error because node_modules still had newer modules used by branch I switched from.

Converting a JS object to an array using jQuery

If you know the maximum index in you object you can do the following:

_x000D_

var myObj = {_x000D_
    1: ['c', 'd'],_x000D_
    2: ['a', 'b']_x000D_
  },_x000D_
  myArr;_x000D_
_x000D_
myObj.length = 3; //max index + 1_x000D_
myArr = Array.prototype.slice.apply(myObj);_x000D_
console.log(myArr); //[undefined, ['c', 'd'], ['a', 'b']]

_x000D_

Checking for empty queryset in Django

If you have a huge number of objects, this can (at times) be much faster:

try:
    orgs[0]
    # If you get here, it exists...
except IndexError:
    # Doesn't exist!

On a project I'm working on with a huge database, not orgs is 400+ ms and orgs.count() is 250ms. In my most common use cases (those where there are results), this technique often gets that down to under 20ms. (One case I found, it was 6.)

Could be much longer, of course, depending on how far the database has to look to find a result. Or even faster, if it finds one quickly; YMMV.

EDIT: This will often be slower than orgs.count() if the result isn't found, particularly if the condition you're filtering on is a rare one; as a result, it's particularly useful in view functions where you need to make sure the view exists or throw Http404. (Where, one would hope, people are asking for URLs that exist more often than not.)

How to solve npm error "npm ERR! code ELIFECYCLE"

I was getting this npm ERR! code ELIFECYCLE error while running a build. Clearing the cache and removing the package-lock.json files did not fix it.

In my case there was an Angular build running on a Docker image that was causing this. The root cause turned out to be running the build on Docker in MacOS, which runs the Docker inside a Linux VM, and has by default 2GB memory allocated.

Giving Docker more memory fixed this issue for me. Have to say, the error message could have been quite a bit more clear..

A helpful answer for me was Call retries were exceeded exception while ng build

How to format a number 0..9 to display with 2 digits (it's NOT a date)

In android resources it's rather simple

<string name="smth">%1$02d</string>

Setting std=c99 flag in GCC

Instead of calling /usr/bin/gcc, use /usr/bin/c99. This is the Single-Unix-approved way of invoking a C99 compiler. On an Ubuntu system, this points to a script which invokes gcc after having added the -std=c99 flag, which is precisely what you want.

Stuck while installing Visual Studio 2015 (Update for Microsoft Windows (KB2999226))

Just kill wusa.exe and install KB2999226 manually. Installation will continue without any problems.

FIFO based Queue implementations?

Yeah. Queue

LinkedList being the most trivial concrete implementation.

Can you split a stream into two streams?

I stumbled across this question while looking for a way to filter certain elements out of a stream and log them as errors. So I did not really need to split the stream so much as attach a premature terminating action to a predicate with unobtrusive syntax. This is what I came up with:

public class MyProcess {
    /* Return a Predicate that performs a bail-out action on non-matching items. */
    private static <T> Predicate<T> withAltAction(Predicate<T> pred, Consumer<T> altAction) {
    return x -> {
        if (pred.test(x)) {
            return true;
        }
        altAction.accept(x);
        return false;
    };

    /* Example usage in non-trivial pipeline */
    public void processItems(Stream<Item> stream) {
        stream.filter(Objects::nonNull)
              .peek(this::logItem)
              .map(Item::getSubItems)
              .filter(withAltAction(SubItem::isValid,
                                    i -> logError(i, "Invalid")))
              .peek(this::logSubItem)
              .filter(withAltAction(i -> i.size() > 10,
                                    i -> logError(i, "Too large")))
              .map(SubItem::toDisplayItem)
              .forEach(this::display);
    }
}

How to iterate object in JavaScript?

for(index in dictionary) {
 for(var index in dictionary[]){
    // do something
  }
}

Why did my Git repo enter a detached HEAD state?

The other way to get in a git detached head state is to try to commit to a remote branch. Something like:

git fetch
git checkout origin/foo
vi bar
git commit -a -m 'changed bar'

Note that if you do this, any further attempt to checkout origin/foo will drop you back into a detached head state!

The solution is to create your own local foo branch that tracks origin/foo, then optionally push.

This probably has nothing to do with your original problem, but this page is high on the google hits for "git detached head" and this scenario is severely under-documented.

How to launch another aspx web page upon button click?

If you'd like to use Code Behind, may I suggest the following solution for an asp:button -

ASPX Page

<asp:Button ID="btnRecover" runat="server" Text="Recover" OnClick="btnRecover_Click" />

Code Behind

    protected void btnRecover_Click(object sender, EventArgs e)
    {
        var recoveryId = Guid.Parse(lbRecovery.SelectedValue);
        var url = string.Format("{0}?RecoveryId={1}", @"../Recovery.aspx", vehicleId);

        // Response.Redirect(url); // Old way

        Response.Write("<script> window.open( '" + url + "','_blank' ); </script>");
        Response.End();
    }

What does android:layout_weight mean?

As the name suggests, Layout weight specifies what amount or percentage of space a particular field or widget should occupy the screen space.
If we specify weight in horizontal orientation, then we must specify layout_width = 0px.
Similarly, If we specify weight in vertical orientation, then we must specify layout_height = 0px.

Hashmap holding different data types as values for instance Integer, String and Object

You have some variables that are different types in Java language like that:

 message of type string
 timestamp of type time
 count of type integer
 version of type integer

If you use a HashMap like:

HashMap<String,Object> yourHash = new HashMap<String,Object>();
yourHash.put("message","message");
yourHash.put("timestamp",timestamp);
yourHash.put("count ",count);
yourHash.put("version ",version);

If you want to use the yourHash:

for(String key : yourHash.keySet()){
  String message = (String) yourHash.get(key);
  Datetime timestamp= (Datetime) yourHash.get(key);
  int timestamp= (int) yourHash.get(key);
}

In plain English, what does "git reset" do?

TL;DR

git reset resets Staging to the last commit. Use --hard to also reset files in your Working directory to the last commit.

LONGER VERSION

But that's obviously simplistic hence the many rather verbose answers. It made more sense for me to read up on git reset in the context of undoing changes. E.g. see this:

If git revert is a “safe” way to undo changes, you can think of git reset as the dangerous method. When you undo with git reset(and the commits are no longer referenced by any ref or the reflog), there is no way to retrieve the original copy—it is a permanent undo. Care must be taken when using this tool, as it’s one of the only Git commands that has the potential to lose your work.

From https://www.atlassian.com/git/tutorials/undoing-changes/git-reset

and this

On the commit-level, resetting is a way to move the tip of a branch to a different commit. This can be used to remove commits from the current branch.

From https://www.atlassian.com/git/tutorials/resetting-checking-out-and-reverting/commit-level-operations

Is it possible to install another version of Python to Virtualenv?

I have not found suitable answer, so here goes my take, which builds upon @toszter answer, but does not use system Python (and you may know, it is not always good idea to install setuptools and virtualenv at system level when dealing with many Python configurations):

#!/bin/sh

mkdir python_ve
cd python_ve

MYROOT=`pwd`
mkdir env pyenv dep

cd ${MYROOT}/dep
wget https://pypi.python.org/packages/source/s/setuptools/setuptools-15.2.tar.gz#md5=a9028a9794fc7ae02320d32e2d7e12ee
wget https://raw.github.com/pypa/virtualenv/master/virtualenv.py
wget https://www.python.org/ftp/python/2.7.9/Python-2.7.9.tar.xz
xz -d Python-2.7.9.tar.xz

cd ${MYROOT}/pyenv
tar xf ../dep/Python-2.7.9.tar
cd Python-2.7.9
./configure --prefix=${MYROOT}/pyenv && make -j 4 && make install

cd ${MYROOT}/pyenv

tar xzf ../dep/setuptools-15.2.tar.gz

cd ${MYROOT}

pyenv/bin/python dep/virtualenv.py --no-setuptools --python=${MYROOT}/pyenv/bin/python --verbose env
env/bin/python pyenv/setuptools-15.2/setup.py install
env/bin/easy_install pip

echo "virtualenv in ${MYROOT}/env"

The trick of breaking chicken-egg problem here is to make virtualenv without setuptools first, because it otherwise fails (pip can not be found). It may be possible to install pip / wheel directly, but somehow easy_install was the first thing which came to my mind. Also, the script can be improved by factoring out concrete versions.

NB. Using xz in the script.

How to Convert double to int in C?

This is the notorious floating point rounding issue. Just add a very small number, to correct the issue.

double a;
a=3669.0;
int b;
b=a+ 1e-9;

Razor view engine - How can I add Partial Views

If you don't want to duplicate code, and like me you just want to show stats, in your view model, you could just pass in the models you want to get data from like so:

public class GameViewModel
{
    public virtual Ship Ship { get; set; }
    public virtual GamePlayer GamePlayer { get; set; }     
}

Then, in your controller just run your queries on the respective models, pass them to the view model and return it, example:

GameViewModel PlayerStats = new GameViewModel();

GamePlayer currentPlayer = (from c in db.GamePlayer [more queries]).FirstOrDefault();

[code to check if results]

//pass current player into custom view model
PlayerStats.GamePlayer = currentPlayer;

Like I said, you should only really do this if you want to display stats from the relevant tables, and there's no other part of the CRUD process happening, for security reasons other people have mentioned above.

How can I specify my .keystore file with Spring Boot and Tomcat?

And here's an example of the customizer implemented in Groovy:

https://github.com/UniconLabs/orville/blob/master/web/src/main/groovy/org/apereo/openregistry/config/TomcatSslConfiguration.groovy

sklearn error ValueError: Input contains NaN, infinity or a value too large for dtype('float64')

i got the same error. it worked with df.fillna(-99999, inplace=True) before doing any replacement, substitution etc

How to format background color using twitter bootstrap?

Just add a div around the container so it looks like:

<div style="background: red;">
  <div class="container marketing">
    <h2 style="padding-top: 60px;"></h2>
  </div>
</div>

MySQL Workbench not displaying query results

The problem, as it is described, corresponds exactly to the bug MySQL Bugs: #74147: empty grid result, incompatibiliity with libglib_2.42

The good news is it's almost closed.

A patch is available since today.

EDIT : In Debian Jessie (testing), the problem is solved with the package mysql-workbench 6.2.3+dfsg-6 available since today.

Controlling a USB power supply (on/off) with Linux

I have found these solutions that at least work for properly configured Terminus FE 1.1 USB hub chip:

1.To turn off power on all USB ports of a hub, you may unbind the hub from kernel using:

echo "1-4.4.4" > /sys/bus/usb/drivers/usb/unbind

to turn power back on - you may bind it back using

echo "1-4.4.4" > /sys/bus/usb/drivers/usb/bind

2.Switching power at each port individually is trickier: I was able to use hubpower to control each port - but it comes with a downside: hubpower first disconnects the usbdevfs wich causes all of the USB devices to disconect from system, at least on ubuntu:

usb_ioctl.ioctl_code = USBDEVFS_DISCONNECT;
rc = ioctl(fd, USBDEVFS_IOCTL, &usb_ioctl);

With this ioctl disabled I was able to switch off individual port power without detaching all devices - but the power goes back on immediately (probably due to kernel seeing an uninitialized device) which causes USB device just to do a "cold restart" which is what I generally wanted to do. My patched hubpower is here

View a file in a different Git branch without changing branches

If you're using Emacs, you can type C-x v ~ to see a different revision of the file you're currently editing (tags, branches and hashes all work).

SQL command to display history of queries

You 'll find it there

~/.mysql_history

You 'll make it readable (without the escapes) like this:

sed "s/\\\040/ /g" < .mysql_history

java: HashMap<String, int> not working

int is a primitive type, you can read what does mean a primitive type in java here, and a Map is an interface that has to objects as input:

public interface Map<K extends Object, V extends Object>

object means a class, and it means also that you can create an other class that exends from it, but you can not create a class that exends from int. So you can not use int variable as an object. I have tow solutions for your problem:

Map<String, Integer> map = new HashMap<>();

Map<String, int[]> map = new HashMap<>();
int x = 1;

//put x in map
int[] x_ = new int[]{x};
map.put("x", x_);

//get the value of x
int y = map.get("x")[0];

How to make html table vertically scrollable

I fought with this one for a while. My goal was to have a table with headers where the widths of the each header column was the the same as the corresponding body column and was the minimum size necessary to fit the data. also the body data was scrollable underneath header.

I solved this by using divs and not tables. Each "table" was a div with the header being a div of divs and the body being a div of divs. I used the style as indicated by @sushil above. I added a bit of javascript/jQuery to balance the columns. Maybe 20-30 lines.

Unfortunately I lost the code and have to rebuild it. I know this is a bit old, but maybe it will help someone else.

ASP.NET jQuery Ajax Calling Code-Behind Method

This hasn't solved my problem too, so I changed the parameters slightly.
This code worked for me:

var dataValue = "{ name: 'person', isGoing: 'true', returnAddress: 'returnEmail' }";

$.ajax({
    type: "POST",
    url: "Default.aspx/OnSubmit",
    data: dataValue,
    contentType: 'application/json; charset=utf-8',
    dataType: 'json',
    error: function (XMLHttpRequest, textStatus, errorThrown) {
        alert("Request: " + XMLHttpRequest.toString() + "\n\nStatus: " + textStatus + "\n\nError: " + errorThrown);
    },
    success: function (result) {
        alert("We returned: " + result.d);
    }
});

How to download Visual Studio Community Edition 2015 (not 2017)

You can use these links to download Visual Studio 2015

Community Edition:

And for anyone in the future who might be looking for the other editions here are the links for them as well:

Professional Edition:

Enterprise Edition:

Mocking python function based on input arguments

You can also use partial from functools if you want to use a function that takes parameters but the function you are mocking does not. E.g. like this:

def mock_year(year):
    return datetime.datetime(year, 11, 28, tzinfo=timezone.utc)

@patch('django.utils.timezone.now', side_effect=partial(mock_year, year=2020))

This will return a callable that doesn't accept parameters (like Django's timezone.now()), but my mock_year function does.

How to create an empty matrix in R?

To get rid of the first column of NAs, you can do it with negative indexing (which removes indices from the R data set). For example:

output = matrix(1:6, 2, 3) # gives you a 2 x 3 matrix filled with the numbers 1 to 6

# output = 
#           [,1] [,2] [,3]
#     [1,]    1    3    5
#     [2,]    2    4    6

output = output[,-1] # this removes column 1 for all rows

# output = 
#           [,1] [,2]
#     [1,]    3    5
#     [2,]    4    6

So you can just add output = output[,-1]after the for loop in your original code.

How can I remove a commit on GitHub?

Note: please see an alternative to git rebase -i in the comments below—

git reset --soft HEAD^

First, remove the commit on your local repository. You can do this using git rebase -i. For example, if it's your last commit, you can do git rebase -i HEAD~2 and delete the second line within the editor window that pops up.

Then, force push to GitHub by using git push origin +branchName --force

See Git Magic Chapter 5: Lessons of History - And Then Some for more information (i.e. if you want to remove older commits).

Oh, and if your working tree is dirty, you have to do a git stash first, and then a git stash apply after.

SQL Server find and replace specific word in all rows of specific column

You can also export the database and then use a program like notepad++ to replace words and then inmport aigain.

jquery click event not firing?

Is this markup added to the DOM asynchronously? You will need to use live in that case:

NOTE: .live has been deprecated and removed in the latest versions of jQuery (for good reason). Please refer to the event delegation strategy below for usage and solution.

<script>
    $(document).ready(function(){
        $('.play_navigation a').live('click', function(){
            console.log("this is the click");
            return false;
        });
    });
</script>

The fact that you are able to re-run your script block and have it work tells me that for some reason the elements weren't available at the time of binding or the binding was removed at some point. If the elements weren't there at bind-time, you will need to use live (or event delegation, preferably). Otherwise, you need to check your code for something else that would be removing the binding.

Using jQuery 1.7 event delegation:

$(function () {

    $('.play_navigation').on('click', 'a', function (e) {
        console.log('this is the click');
        e.preventDefault();
    });

});

You can also delegate events up to the document if you feel that you would like to bind the event before the document is ready (note that this also causes jQuery to examine every click event to determine if the element matches the appropriate selector):

$(document).on('click', '.play_navigation a', function (e) {
    console.log('this is the click');
    e.preventDefault();
});

Using Pipes within ngModel on INPUT Elements in Angular

My Solution is given below here searchDetail is an object..

<p-calendar  [ngModel]="searchDetail.queryDate | date:'MM/dd/yyyy'"  (ngModelChange)="searchDetail.queryDate=$event" [showIcon]="true" required name="queryDate" placeholder="Enter the Query Date"></p-calendar>

<input id="float-input" type="text" size="30" pInputText [ngModel]="searchDetail.systems | json"  (ngModelChange)="searchDetail.systems=$event" required='true' name="systems"
            placeholder="Enter the Systems">

Calculate date/time difference in java

I would prefer to use suggested java.util.concurrent.TimeUnit class.

long diff = d2.getTime() - d1.getTime();//as given

long seconds = TimeUnit.MILLISECONDS.toSeconds(diff);
long minutes = TimeUnit.MILLISECONDS.toMinutes(diff);

How do I save and restore multiple variables in python?

There is a built-in library called pickle. Using pickle you can dump objects to a file and load them later.

import pickle

f = open('store.pckl', 'wb')
pickle.dump(obj, f)
f.close()

f = open('store.pckl', 'rb')
obj = pickle.load(f)
f.close()

How do I include a JavaScript file in another JavaScript file?

It is possible to dynamically generate a JavaScript tag and append it to HTML document from inside other JavaScript code. This will load targeted JavaScript file.

function includeJs(jsFilePath) {
    var js = document.createElement("script");

    js.type = "text/javascript";
    js.src = jsFilePath;

    document.body.appendChild(js);
}

includeJs("/path/to/some/file.js");

Loading and parsing a JSON file with multiple JSON objects

You have a JSON Lines format text file. You need to parse your file line by line:

import json

data = []
with open('file') as f:
    for line in f:
        data.append(json.loads(line))

Each line contains valid JSON, but as a whole, it is not a valid JSON value as there is no top-level list or object definition.

Note that because the file contains JSON per line, you are saved the headaches of trying to parse it all in one go or to figure out a streaming JSON parser. You can now opt to process each line separately before moving on to the next, saving memory in the process. You probably don't want to append each result to one list and then process everything if your file is really big.

If you have a file containing individual JSON objects with delimiters in-between, use How do I use the 'json' module to read in one JSON object at a time? to parse out individual objects using a buffered method.

How to change Tkinter Button state from disabled to normal?

I think a quick way to change the options of a widget is using the configure method.

In your case, it would look like this:

self.x.configure(state=NORMAL)

Using Spring MVC Test to unit test multipart POST request

The method MockMvcRequestBuilders.fileUpload is deprecated use MockMvcRequestBuilders.multipart instead.

This is an example:

import static org.hamcrest.CoreMatchers.containsString;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.ResultActions;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.multipart.MultipartFile;


/**
 * Unit test New Controller.
 *
 */
@RunWith(SpringRunner.class)
@WebMvcTest(NewController.class)
public class NewControllerTest {

    private MockMvc mockMvc;

    @Autowired
    WebApplicationContext wContext;

    @MockBean
    private NewController newController;

    @Before
    public void setup() {
        this.mockMvc = MockMvcBuilders.webAppContextSetup(wContext)
                   .alwaysDo(MockMvcResultHandlers.print())
                   .build();
    }

   @Test
    public void test() throws Exception {
       // Mock Request
        MockMultipartFile jsonFile = new MockMultipartFile("test.json", "", "application/json", "{\"key1\": \"value1\"}".getBytes());

        // Mock Response
        NewControllerResponseDto response = new NewControllerDto();
        Mockito.when(newController.postV1(Mockito.any(Integer.class), Mockito.any(MultipartFile.class))).thenReturn(response);

        mockMvc.perform(MockMvcRequestBuilders.multipart("/fileUpload")
                .file("file", jsonFile.getBytes())
                .characterEncoding("UTF-8"))
        .andExpect(status().isOk());

    }

}

HTML 'td' width and height

Following width worked well in HTML5: -

<table >
  <tr>
    <th style="min-width:120px">Month</th>
    <th style="min-width:60px">Savings</th>
  </tr>
  <tr>
    <td>January</td>
    <td>$100</td>
  </tr>
  <tr>
    <td>February</td>
    <td>$80</td>
  </tr>
</table>

Please note that

TD tag is without CSS style.

jQuery object equality

Use Underscore.js isEqual method http://underscorejs.org/#isEqual

Confused about str on list in Python

Well, container objects' __str__ methods will use repr on their contents, not str. So you could use __repr__ instead of __str__, seeing as you're using an ID as the result.

Regular expression field validation in jQuery

Unless you're looking for something specific, you can already do Regular Expression matching using regular Javascript with strings.

For example, you can do matching using a string by something like this...

var phrase = "This is a phrase";
phrase = phrase.replace(/is/i, "is not");
alert(phrase);

Is there something you're looking for other than just Regular Expression matching in general?

How do I get a Cron like scheduler in Python?

I like how the pycron package solves this problem.

import pycron
import time

while True:
    if pycron.is_now('0 2 * * 0'):   # True Every Sunday at 02:00
        print('running backup')
        time.sleep(60)               # The process should take at least 60 sec
                                     # to avoid running twice in one minute
    else:
        time.sleep(15)               # Check again in 15 seconds

What is the difference between a token and a lexeme?

Token: The kind for (keywords,identifier,punctuation character, multi-character operators) is ,simply, a Token.

Pattern: A rule for formation of token from input characters.

Lexeme : Its a sequence of characters in SOURCE PROGRAM matched by a pattern for a token. Basically, its an element of Token.

Check if a variable is of function type

_x000D_

var foo = function(){};_x000D_
if (typeof foo === "function") {_x000D_
  alert("is function")_x000D_
}

_x000D_

Remove all padding and margin table HTML and CSS

Try to use this CSS:

/* Apply this to your `table` element. */
#page {
   border-collapse: collapse;
}

/* And this to your table's `td` elements. */
#page td {
   padding: 0; 
   margin: 0;
}

How to get the response of XMLHttpRequest?

You can get it by XMLHttpRequest.responseText in XMLHttpRequest.onreadystatechange when XMLHttpRequest.readyState equals to XMLHttpRequest.DONE.

Here's an example (not compatible with IE6/7).

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
    if (xhr.readyState == XMLHttpRequest.DONE) {
        alert(xhr.responseText);
    }
}
xhr.open('GET', 'http://example.com', true);
xhr.send(null);

For better crossbrowser compatibility, not only with IE6/7, but also to cover some browser-specific memory leaks or bugs, and also for less verbosity with firing ajaxical requests, you could use jQuery.

$.get('http://example.com', function(responseText) {
    alert(responseText);
});

Note that you've to take the Same origin policy for JavaScript into account when not running at localhost. You may want to consider to create a proxy script at your domain.

Determine if Android app is being used for the first time

You can use the SharedPreferences to identify if it is the "First time" the app is launched. Just use a Boolean variable ("my_first_time") and change its value to false when your task for "first time" is over.

This is my code to catch the first time you open the app:

final String PREFS_NAME = "MyPrefsFile";

SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);

if (settings.getBoolean("my_first_time", true)) {
    //the app is being launched for first time, do something        
    Log.d("Comments", "First time");

             // first time task

    // record the fact that the app has been started at least once
    settings.edit().putBoolean("my_first_time", false).commit(); 
}

How to get character for a given ascii value

Simply Try this:

int n = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("data is: {0}", Convert.ToChar(n));

Clear text in EditText when entered

Also you can use code below

editText.getText().clear();

How to unzip a file in Powershell?

Use Expand-Archive cmdlet with one of parameter set:

Expand-Archive -LiteralPath C:\source\file.Zip -DestinationPath C:\destination

Expand-Archive -Path file.Zip -DestinationPath C:\destination

How do you set a JavaScript onclick event to a class with css

You can't do it with just CSS, but you can do it with Javascript, and (optionally) jQuery.

If you want to do it without jQuery:

<script>
    window.onload = function() {
        var anchors = document.getElementsByTagName('a');
        for(var i = 0; i < anchors.length; i++) {
            var anchor = anchors[i];
            anchor.onclick = function() {
                alert('ho ho ho');
            }
        }
    }
</script>

And to do it without jQuery, and only on a specific class (ex: hohoho):

<script>
    window.onload = function() {
        var anchors = document.getElementsByTagName('a');
        for(var i = 0; i < anchors.length; i++) {
            var anchor = anchors[i];
            if(/\bhohoho\b/).match(anchor.className)) {
                anchor.onclick = function() {
                    alert('ho ho ho');
                }
            }
        }
    }
</script>

If you are okay with using jQuery, then you can do this for all anchors:

<script>
    $(document).ready(function() {
        $('a').click(function() {
            alert('ho ho ho');
        });
    });
</script>

And this jQuery snippet to only apply it to anchors with a specific class:

<script>
    $(document).ready(function() {
        $('a.hohoho').click(function() {
            alert('ho ho ho');
        });
    });
</script>

Best way to find if an item is in a JavaScript array?

If you are using jQuery:

$.inArray(5 + 5, [ "8", "9", "10", 10 + "" ]);

For more information: http://api.jquery.com/jQuery.inArray/

How to do multiple conditions for single If statement

Use the 'And' keyword for a logical and. Like this:

If Not ((filename = testFileName) And (fileName <> "")) Then

How do I change column default value in PostgreSQL?

If you want to remove the default value constraint, you can do:

ALTER TABLE <table> ALTER COLUMN <column> DROP DEFAULT;

Getting "net::ERR_BLOCKED_BY_CLIENT" error on some AJAX calls

As it has been explained here, beside of multiple extensions that perform ad or script blocking you may aware that this may happen by file names as below:

Particularly in the AdBlock Plus the character string "-300x600" is causing the Failed to Load Resource ERR_BLOCKED_BY_CLIENT problem.

As shown in the picture, some of the images were blocked because of the '-300x600' pattern in their name, that particular text pattern matches an expression list pattern in the AdBlock Plus.

No suitable records were found verify your bundle identifier is correct

Using Application Loader worked in my case.

How to discard local changes and pull latest from GitHub repository

git reset is what you want, but I'm going to add a couple extra things you might find useful that the other answers didn't mention.

git reset --hard HEAD resets your changes back to the last commit that your local repo has tracked. If you made a commit, did not push it to GitHub, and want to throw that away too, see @absiddiqueLive's answer.

git clean -df will discard any new files or directories that you may have added, in case you want to throw those away. If you haven't added any, you don't have to run this.

git pull (or if you are using git shell with the GitHub client) git sync will get the new changes from GitHub.

Edit from way in the future: I updated my git shell the other week and noticed that the git sync command is no longer defined by default. For the record, typing git sync was equivalent to git pull && git push in bash. I find it still helpful so it is in my bashrc.

C# DateTime.ParseExact

It's probably the same problem with cultures as presented in this related SO-thread: Why can't DateTime.ParseExact() parse "9/1/2009" using "M/d/yyyy"

You already specified the culture, so try escaping the slashes.

How to update column value in laravel

I tried to update a field with

$table->update(['field' => 'val']);

But it wasn't working, i had to modify my table Model to authorize this field to be edited : add 'field' in the array "protected $fillable"

Hope it will help someone :)

How to check what user php is running as?

You can use these commands :

<? system('whoami');?>

<? passthru('whoami');?>

<? print exec('whoami');?>

<? print shell_exec('whoami');?>

Be aware, the get_current_user() returns the name of the owner of the current PHP script !

How to edit HTML input value colour?

Maybe something like this (just add your style):

<input type="text" 
       size="35" 
       value="Job Title e.g. Assistant Manager" 
       style="background-color:white; 
              border: solid 1px #6E6E6E;
              height: 30px; 
              font-size:18px; 
              vertical-align:9px;color:#bbb" 
        onfocus="if(this.value == 'Job Title e.g. Assistant Manager') {
                    this.value = '';
                    this.style.color='#000';
                 }" />

<input type="text" 
       name="searchterm" size="35" 
       style="background-color:white; 
              border: solid 1px #6E6E6E;
              height: 30px; 
              font-size:18px; 
              vertical-align:9px" />

UPDATE: Since placeholder attribute is very well supported on all major browsers, there is no need to do anything manually. Its possible to achieve the same thing with this:

<input type="text" 
       size="35" 
       placeholder="Job Title e.g. Assistant Manager" />

Git push existing repo to a new and different remote repo server?

Create a new repo at github.
Clone the repo from fedorahosted to your local machine.
git remote rename origin upstream
git remote add origin URL_TO_GITHUB_REPO
git push origin master

Now you can work with it just like any other github repo. To pull in patches from upstream, simply run git pull upstream master && git push origin master.

Finding elements not in a list

Using list comprehension:

print [x for x in item if x not in Z]

or using filter function :

filter(lambda x: x not in Z, item)

Using set in any form may create a bug if the list being checked contains non-unique elements, e.g.:

print item

Out[39]: [0, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9]

print Z

Out[40]: [3, 4, 5, 6]

set(item) - set(Z)

Out[41]: {0, 1, 2, 7, 8, 9}

vs list comprehension as above

print [x for x in item if x not in Z]

Out[38]: [0, 1, 1, 2, 7, 8, 9]

or filter function:

filter(lambda x: x not in Z, item)

Out[38]: [0, 1, 1, 2, 7, 8, 9]

How to convert Hexadecimal #FFFFFF to System.Drawing.Color

You can do

var color =  System.Drawing.ColorTranslator.FromHtml("#FFFFFF");

Or this (you will need the System.Windows.Media namespace)

var color = (Color)ColorConverter.ConvertFromString("#FFFFFF");

How to center HTML5 Videos?

Do this:

<video style="display:block; margin: 0 auto;" controls>....</video>

Works perfect! :D

What is the best way to insert source code examples into a Microsoft Word document?

I have tried all your methods, but they didn't work for me, in fact I have created an easier method using MS Word Tables.

Pros:

More beautiful
Easier to manage & more consistent
Are less prone to problems
No need for external plugins or MS Word micro coding.
Easier to handle by simple users (such as myself).

Cons: It will not maintain code colouring although someone could improve my trick.

Steps:

Insert a 3x3 table, in my case I always make the total width of the table equals the free page's width (3 rows minimum to test the tables style).
Use invisible borders ("No Borders" option), and activate "View Gridlines" option. it should have this aspect. Be ware that those lines are for you to see the table's grid, and the will not be printed.

Make the adjustments to cells' spacing and columns' width to get the aspect you like. (You will have to get in "Table Properties" for fine tuning).
Create a "Paragraph Style" with the name of "Code" just for your code snippets (check https://stackoverflow.com/a/25092977/8533804 to get the idea, you don't have to follow all of it)
Create another "Paragraph Style" with the name of "Code_numberline" that will be based upon the previous created style.
In the newly created "Code_numberline" add the numbering style that you like (this will automate line numbering).
Apply "Code_numberline" to the first column, and "Code" to the 3 column.
Add a fill in the middle column.
Save that table style and enjoy!

What is uintptr_t data type

There are already many good answers to the part "what is uintptr_t data type". I will try to address the "what it can be used for?" part in this post.

Primarily for bitwise operations on pointers. Remember that in C++ one cannot perform bitwise operations on pointers. For reasons see Why can't you do bitwise operations on pointer in C, and is there a way around this?

Thus in order to do bitwise operations on pointers one would need to cast pointers to type unitpr_t and then perform bitwise operations.

Here is an example of a function that I just wrote to do bitwise exclusive or of 2 pointers to store in a XOR linked list so that we can traverse in both directions like a doubly linked list but without the penalty of storing 2 pointers in each node.

 template <typename T>
 T* xor_ptrs(T* t1, T* t2)
 {
     return reinterpret_cast<T*>(reinterpret_cast<uintptr_t>(t1)^reinterpret_cast<uintptr_t>(t2));
  }

How to create and use resources in .NET

Well, after searching around and cobbling together various points from around StackOverflow (gee, I love this place already), most of the problems were already past this stage. I did manage to work out an answer to my problem though.

How to create a resource:

In my case, I want to create an icon. It's a similar process, no matter what type of data you want to add as a resource though.

Right click the project you want to add a resource to. Do this in the Solution Explorer. Select the "Properties" option from the list.
Click the "Resources" tab.
The first button along the top of the bar will let you select the type of resource you want to add. It should start on string. We want to add an icon, so click on it and select "Icons" from the list of options.
Next, move to the second button, "Add Resource". You can either add a new resource, or if you already have an icon already made, you can add that too. Follow the prompts for whichever option you choose.
At this point, you can double click the newly added resource to edit it. Note, resources also show up in the Solution Explorer, and double clicking there is just as effective.

How to use a resource:

Great, so we have our new resource and we're itching to have those lovely changing icons... How do we do that? Well, lucky us, C# makes this exceedingly easy.

There is a static class called Properties.Resources that gives you access to all your resources, so my code ended up being as simple as:

paused = !paused;
if (paused)
    notifyIcon.Icon = Properties.Resources.RedIcon;
else
    notifyIcon.Icon = Properties.Resources.GreenIcon;

Done! Finished! Everything is simple when you know how, isn't it?

Difference between "include" and "require" in php

You find the differences explained in the detailed PHP manual on the page of require:

require is identical to include except upon failure it will also produce a fatal E_COMPILE_ERROR level error. In other words, it will halt the script whereas include only emits a warning (E_WARNING) which allows the script to continue.

See @efritz's answer for an example

Difference between partition key, composite key and clustering key in Cassandra?

The primary key in Cassandra usually consists of two parts - Partition key and Clustering columns.

primary_key((partition_key), clustering_col )

Partition key - The first part of the primary key. The main aim of a partition key is to identify the node which stores the particular row.

CREATE TABLE phone_book ( phone_num int, name text, age int, city text, PRIMARY KEY ((phone_num, name), age);

Here, (phone_num, name) is the partition key. While inserting the data, the hash value of the partition key is generated and this value decides which node the row should go into.

Consider a 4 node cluster, each node has a range of hash values it can store. (Write) INSERT INTO phone_book VALUES (7826573732, ‘Joey’, 25, ‘New York’);

Now, the hash value of the partition key is calculated by Cassandra partitioner. say, hash value(7826573732, ‘Joey’) ? 12 , now, this row will be inserted in Node C.

(Read) SELECT * FROM phone_book WHERE phone_num=7826573732 and name=’Joey’;

Now, again the hash value of the partition key (7826573732,’Joey’) is calculated, which is 12 in our case which resides in Node C, from which the read is done.

Clustering columns - Second part of the primary key. The main purpose of having clustering columns is to store the data in a sorted order. By default, the order is ascending.

There can be more than one partition key and clustering columns in a primary key depending on the query you are solving.

primary_key((pk1, pk2), col 1,col2)

What's the canonical way to check for type in Python?

isinstance(o, str) will return True if o is an str or is of a type that inherits from str.

type(o) is str will return True if and only if o is a str. It will return False if o is of a type that inherits from str.

multiple conditions for JavaScript .includes() method

Here's a controversial option:

String.prototype.includesOneOf = function(arrayOfStrings) {
  if(!Array.isArray(arrayOfStrings)) {
    throw new Error('includesOneOf only accepts an array')
  }
  return arrayOfStrings.some(str => this.includes(str))
}

Allowing you to do things like:

'Hi, hope you like this option'.toLowerCase().includesOneOf(["hello", "hi", "howdy"]) // True

Getting the index of a particular item in array

FindIndex Extension

static class ArrayExtensions
{
    public static int FindIndex<T>(this T[] array, Predicate<T> match)
    {
        return Array.FindIndex(array, match);
    }
}

Usage

int[] array = { 9,8,7,6,5 };

var index = array.FindIndex(i => i == 7);

Console.WriteLine(index); // Prints "2"

Here's a fiddle with it.

Bonus: IndexOf Extension

I wrote this first not reading the question properly...

static class ArrayExtensions
{
    public static int IndexOf<T>(this T[] array, T value)
    {
        return Array.IndexOf(array, value);
    }   
}

Usage

int[] array = { 9,8,7,6,5 };

var index = array.IndexOf(7);

Console.WriteLine(index); // Prints "2"

Here's a fiddle with it.

How can I do a line break (line continuation) in Python?

What is the line? You can just have arguments on the next line without any problems:

a = dostuff(blahblah1, blahblah2, blahblah3, blahblah4, blahblah5, 
            blahblah6, blahblah7)

Otherwise you can do something like this:

if (a == True and
    b == False):

or with explicit line break:

if a == True and \
   b == False:

Check the style guide for more information.

Using parentheses, your example can be written over multiple lines:

a = ('1' + '2' + '3' +
    '4' + '5')

The same effect can be obtained using explicit line break:

a = '1' + '2' + '3' + \
    '4' + '5'

Note that the style guide says that using the implicit continuation with parentheses is preferred, but in this particular case just adding parentheses around your expression is probably the wrong way to go.

Multi-Column Join in Hibernate/JPA Annotations

If this doesn't work I'm out of ideas. This way you get the 4 columns in both tables (as Bar owns them and Foo uses them to reference Bar) and the generated IDs in both entities. The set of 4 columns has to be unique in Bar so the many-to-one relation doesn't become a many-to-many.

@Embeddable
public class AnEmbeddedObject
{
    @Column(name = "column_1")
    private Long column1;
    @Column(name = "column_2")
    private Long column2;
    @Column(name = "column_3")
    private Long column3;
    @Column(name = "column_4")
    private Long column4;
}

@Entity
public class Foo
{
    @Id
    @Column(name = "id")
    @GeneratedValue(generator = "seqGen")
    @SequenceGenerator(name = "seqGen", sequenceName = "FOO_ID_SEQ", allocationSize = 1)
    private Long id;
    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumns({
        @JoinColumn(name = "column_1", referencedColumnName = "column_1"),
        @JoinColumn(name = "column_2", referencedColumnName = "column_2"),
        @JoinColumn(name = "column_3", referencedColumnName = "column_3"),
        @JoinColumn(name = "column_4", referencedColumnName = "column_4")
    })
    private Bar bar;
}

@Entity
@Table(uniqueConstraints = @UniqueConstraint(columnNames = {
    "column_1",
    "column_2",
    "column_3",
    "column_4"
}))
public class Bar
{
    @Id
    @Column(name = "id")
    @GeneratedValue(generator = "seqGen")
    @SequenceGenerator(name = "seqGen", sequenceName = "BAR_ID_SEQ", allocationSize = 1)
    private Long id;
    @Embedded
    private AnEmbeddedObject anEmbeddedObject;
}

How do I update Node.js?

The easy way to update node and npm :

npm install -g npm@latest

download the latest version of node js and update /install

What's the best practice using a settings file in Python?

I Found this the most useful and easy to use https://wiki.python.org/moin/ConfigParserExamples

You just create a "myfile.ini" like:

[SectionOne]
Status: Single
Name: Derek
Value: Yes
Age: 30
Single: True

[SectionTwo]
FavoriteColor=Green
[SectionThree]
FamilyName: Johnson

[Others]
Route: 66

And retrieve the data like:

>>> import ConfigParser
>>> Config = ConfigParser.ConfigParser()
>>> Config
<ConfigParser.ConfigParser instance at 0x00BA9B20>
>>> Config.read("myfile.ini")
['c:\\tomorrow.ini']
>>> Config.sections()
['Others', 'SectionThree', 'SectionOne', 'SectionTwo']
>>> Config.options('SectionOne')
['Status', 'Name', 'Value', 'Age', 'Single']
>>> Config.get('SectionOne', 'Status')
'Single'

Razor If/Else conditional operator syntax

You need to put the entire ternary expression in parenthesis. Unfortunately that means you can't use "@:", but you could do something like this:

@(deletedView ? "Deleted" : "Created by")

Razor currently supports a subset of C# expressions without using @() and unfortunately, ternary operators are not part of that set.

What to do with branch after merge

After the merge, it's safe to delete the branch:

git branch -d branch1

Additionally, git will warn you (and refuse to delete the branch) if it thinks you didn't fully merge it yet. If you forcefully delete a branch (with git branch -D) which is not completely merged yet, you have to do some tricks to get the unmerged commits back though (see below).

There are some reasons to keep a branch around though. For example, if it's a feature branch, you may want to be able to do bugfixes on that feature still inside that branch.

If you also want to delete the branch on a remote host, you can do:

git push origin :branch1

This will forcefully delete the branch on the remote (this will not affect already checked-out repositiories though and won't prevent anyone with push access to re-push/create it).

git reflog shows the recently checked out revisions. Any branch you've had checked out in the recent repository history will also show up there. Aside from that, git fsck will be the tool of choice at any case of commit-loss in git.

How can I change my default database in SQL Server without using MS SQL Server Management Studio?

If you use windows authentication, and you don't know a password to login as a user via username and password, you can do this: on the login-screen on SSMS click options at the bottom right, then go to the connection properties tab. Then you can type in manually the name of another database you have access to, over where it says , which will let you connect. Then follow the other advice for changing your default database

https://gyazo.com/c3d04c600311c08cb685bb668b569a67

Best Practice: Access form elements by HTML id or name attribute?

Because the case [2] document.myForm.foo is a dialect from Internet Exploere. So instead of it, I prefer document.forms.myForm.elements.foo or document.forms["myForm"].elements["foo"] .

Char array to hex string C++

You could use std::hex

Eg.

std::cout << std::hex << packet;

Jmeter - Run .jmx file through command line and get the summary report in a excel

You can use this command,

jmeter -n -t /path to the script.jmx -l /path to save results with file name file.jtl

But if you really want to run a load test in a remote machine, you should be able to make it run eventhough you close the window. So we can use nohup to ignore the HUP (hangup) signal. So you can use this command as below.

nohup sh jmeter.sh -n -t /path to the script.jmx -l /path to save results with file name file.jtl &

Difference between opening a file in binary vs text

The most important difference to be aware of is that with a stream opened in text mode you get newline translation on non-*nix systems (it's also used for network communications, but this isn't supported by the standard library). In *nix newline is just ASCII linefeed, \n, both for internal and external representation of text. In Windows the external representation often uses a carriage return + linefeed pair, "CRLF" (ASCII codes 13 and 10), which is converted to a single \n on input, and conversely on output.

From the C99 standard (the N869 draft document), §7.19.2/2,

A text stream is an ordered sequence of characters composed into lines, each line consisting of zero or more characters plus a terminating new-line character. Whether the last line requires a terminating new-line character is implementation-defined. Characters may have to be added, altered, or deleted on input and output to conform to differing conventions for representing text in the host environment. Thus, there need not be a one- to-one correspondence between the characters in a stream and those in the external representation. Data read in from a text stream will necessarily compare equal to the data that were earlier written out to that stream only if: the data consist only of printing characters and the control characters horizontal tab and new-line; no new-line character is immediately preceded by space characters; and the last character is a new-line character. Whether space characters that are written out immediately before a new-line character appear when read in is implementation-defined.

And in §7.19.3/2

Binary files are not truncated, except as defined in 7.19.5.3. Whether a write on a text stream causes the associated file to be truncated beyond that point is implementation- defined.

About use of fseek, in §7.19.9.2/4:

For a text stream, either offset shall be zero, or offset shall be a value returned by an earlier successful call to the ftell function on a stream associated with the same file and whence shall be SEEK_SET.

About use of ftell, in §17.19.9.4:

The ftell function obtains the current value of the file position indicator for the stream pointed to by stream. For a binary stream, the value is the number of characters from the beginning of the file. For a text stream, its file position indicator contains unspecified information, usable by the fseek function for returning the file position indicator for the stream to its position at the time of the ftell call; the difference between two such return values is not necessarily a meaningful measure of the number of characters written or read.

I think that’s the most important, but there are some more details.

A simple explanation of Naive Bayes Classification

I try to explain the Bayes rule with an example.

What is the chance that a random person selected from the society is a smoker?

You may reply 10%, and let's assume that's right.

Now, what if I say that the random person is a man and is 15 years old?

You may say 15 or 20%, but why?.

In fact, we try to update our initial guess with new pieces of evidence ( P(smoker) vs. P(smoker | evidence) ). The Bayes rule is a way to relate these two probabilities.

P(smoker | evidence) = P(smoker)* p(evidence | smoker)/P(evidence)

Each evidence may increase or decrease this chance. For example, this fact that he is a man may increase the chance provided that this percentage (being a man) among non-smokers is lower.

In the other words, being a man must be an indicator of being a smoker rather than a non-smoker. Therefore, if an evidence is an indicator of something, it increases the chance.

But how do we know that this is an indicator?

For each feature, you can compare the commonness (probability) of that feature under the given conditions with its commonness alone. (P(f | x) vs. P(f)).

P(smoker | evidence) / P(smoker) = P(evidence | smoker)/P(evidence)

For example, if we know that 90% of smokers are men, it's not still enough to say whether being a man is an indicator of being smoker or not. For example if the probability of being a man in the society is also 90%, then knowing that someone is a man doesn't help us ((90% / 90%) = 1. But if men contribute to 40% of the society, but 90% of the smokers, then knowing that someone is a man increases the chance of being a smoker (90% / 40%) = 2.25, so it increases the initial guess (10%) by 2.25 resulting 22.5%.

However, if the probability of being a man was 95% in the society, then regardless of the fact that the percentage of men among smokers is high (90%)! the evidence that someone is a man decreases the chance of him being a smoker! (90% / 95%) = 0.95).

So we have:

P(smoker | f1, f2, f3,... ) = P(smoker) * contribution of f1* contribution of f2 *... 
=
P(smoker)* 
(P(being a man | smoker)/P(being a man))*
(P(under 20 | smoker)/ P(under 20))

Note that in this formula we assumed that being a man and being under 20 are independent features so we multiplied them, it means that knowing that someone is under 20 has no effect on guessing that he is man or woman. But it may not be true, for example maybe most adolescence in a society are men...

To use this formula in a classifier

The classifier is given with some features (being a man and being under 20) and it must decide if he is an smoker or not (these are two classes). It uses the above formula to calculate the probability of each class under the evidence (features), and it assigns the class with the highest probability to the input. To provide the required probabilities (90%, 10%, 80%...) it uses the training set. For example, it counts the people in the training set that are smokers and find they contribute 10% of the sample. Then for smokers checks how many of them are men or women .... how many are above 20 or under 20....In the other words, it tries to build the probability distribution of the features for each class based on the training data.

Run Button is Disabled in Android Studio

The above answer didn't work for me, instead closing the project and restaring the AS IDE worked for me.

Factory Pattern. When to use factory methods?

It is good idea to use factory methods inside object when:

Object's class doesn't know what exact sub-classes it have to create
Object's class is designed so that objects it creates were specified by sub-classes
Object's class delegates its duties to auxiliary sub-classes and doesn't know what exact class will take these duties

It is good idea to use abstract factory class when:

Your object shouldn't depend on how its inner objects are created and designed
Group of linked objects should be used together and you need to serve this constraint
Object should be configured by one of several possible families of linked objects that will be a part of your parent object
It is required to share child objects showing interfaces only but not an implementation

Post request in Laravel - Error - 419 Sorry, your session/ 419 your page has expired

If you already have the csrf directive, you might have changed the way sessions runs.

In config/session.php, check the 'secure' field. It should be on false if https isn't available on your server.

You can also put SESSION_SECURE_COOKIE=FALSE on your .env file (root directory).

Converting from signed char to unsigned char and back again?

Yes this is safe.

The c language uses a feature called integer promotion to increase the number of bits in a value before performing calculations. Therefore your CLAMP255 macro will operate at integer (probably 32 bit) precision. The result is assigned to a jbyte, which reduces the integer precision back to 8 bits fit in to the jbyte.

WAMP/XAMPP is responding very slow over localhost

The solution that worked for me was to disable the cgi_module. Use one of these methods:

(Method 1) Right click on WAMP > Apache > Apache Modules > uncheck "cgi_module"

(Method 2) Edit httpd.conf and disable the loading of the CGI module by commenting this line:

LoadModule cgi_module modules/mod_cgi.so

Commenting would be just adding a # in front, like this:

#LoadModule cgi_module modules/mod_cgi.so

Restart the Apache service and you should be good to go.

Explicitly assigning values to a 2D Array?

Advantages of SQL Server 2008 over SQL Server 2005?

SQL Server 2008 introduces four new date and time data types, which include:

* DATE: As you can imagine, the DATE data type only stores a date in the format of YYYY-MM-DD. It has a range of 0001-01-01 through 9999-12-32, which should be adequate for most business and scientific applications. The accuracy is 1 day, and it only takes 3 bytes to store the date.
* TIME: TIME is stored in the format: hh:mm:ss.nnnnnnn, with a range of 00:00:00.0000000 through 23:59:59:9999999 and is accurate to 100 nanoseconds. Storage depends on the precision and scale selected, and runs from 3 to 5 bytes.
* DATETIME2: DATETIME2 is very similar to the older DATETIME data type, but has a greater range and precision. The format is YYYY-MM-DD hh:mm:ss:nnnnnnnm with a range of 0001-01-01 00:00:00.0000000 through 9999-12-31 23:59:59.9999999, and an accuracy of 100 nanoseconds. Storage depends on the precision and scale selected, and runs from 6 to 8 bytes.
* DATETIMEOFFSET: DATETIMEOFFSET is similar to DATETIME2, but includes additional information to track the time zone. The format is YYYY-MM-DD hh:mm:ss[.nnnnnnn] [+|-]hh:mm with a range of 0001-01-01 00:00:00.0000000 through 0001-01-01 00:00:00.0000000 through 9999-12-31 23:59:59.9999999 (in UTC), and an accuracy of 100 nanoseconds. Storage depends on the precision and scale selected, and runs from 8 to 10 bytes.

http://soft-engineering.blogspot.com/

Get current scroll position of ScrollView in React Native

use of onScroll enters infinite loop. onMomentumScrollEnd or onScrollEndDrag can be used instead

Programs & Examples On #Database driven

What's the best strategy for unit-testing database-driven applications?

how to get the ipaddress of a virtual box running on local machine

Getting "project" nuget configuration is invalid error

How to reset postgres' primary key sequence when it falls out of sync?

How to Empty Caches and Clean All Targets Xcode 4 and later

how to hide <li> bullets in navigation menu and footer links BUT show them for listing items

Textarea onchange detection

Get latitude and longitude based on location name with Google Autocomplete API

How to change the font and font size of an HTML input tag?

Maven build Compilation error : Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project Maven

this.getClass().getClassLoader().getResource("...") and NullPointerException

How to remove the bottom border of a box with CSS

How to add an element to the beginning of an OrderedDict?

Update

EF Migrations: Rollback last applied migration?

Best way to randomize an array with .NET

How to find cube root using Python?

JNI and Gradle in Android Studio

Gradle Build Tools 2.2.0+ - The closest the NDK has ever come to being called 'magic'

Android Studio Clean and Build Integration - DEPRECATED

Gradle - for those having issues

Final product - /build.gradle

ndkDirectory

File Not Found when running PHP with Nginx

How do I run PHP code when a user clicks on a link?

How can I check if an InputStream is empty without reading from it?

Horizontal scroll on overflow of table

HashMap allows duplicates?

How to call same method for a list of objects?

How do I create a local database inside of Microsoft SQL Server 2014?

Install Qt on Ubuntu

Why Local Users and Groups is missing in Computer Management on Windows 10 Home?

Validating file types by regular expression

Initializing a two dimensional std::vector

How to copy files from 'assets' folder to sdcard?

How to integrate Dart into a Rails app

Using import fs from 'fs'

The most efficient way to remove first N elements in a list?

list + pop(0)

deque + popleft()

PHP float with 2 decimal places: .00

How to call code behind server method from a client side JavaScript function?

Uploading file using POST request in Node.js

mysqldump exports only one table

Ordering issue with date values when creating pivot tables

Set icon for Android application

How to count the number of set bits in a 32-bit integer?

Merge a Branch into Trunk

how to stop a loop arduino

Replace Line Breaks in a String C#

Remove all files except some from a directory

Permanently adding a file path to sys.path in Python

SQL: Return "true" if list of records exists?

Must JDBC Resultsets and Statements be closed separately although the Connection is closed afterwards?

Custom Adapter for List View

Oracle SELECT TOP 10 records

Check date between two other dates spring data jpa

Foreach in a Foreach in MVC View

How to force Laravel Project to use HTTPS for all routes?

Incrementing in C++ - When to use x++ or ++x?

ERROR: Error 1005: Can't create table (errno: 121)

Dead simple example of using Multiprocessing Queue, Pool and Locking

jQuery datepicker, onSelect won't work

How can I increase the JVM memory?

Extract Number from String in Python

Load Image from javascript

MongoDb query condition on comparing 2 fields

What does java.lang.Thread.interrupt() do?

Why is "1000000000000000 in range(1000000000000001)" so fast in Python 3?

Generating a unique machine id

How to get IntPtr from byte[] in C#

JUNIT Test class in Eclipse - java.lang.ClassNotFoundException

Is there a standardized method to swap two variables in Python?

How do I get current date/time on the Windows command line in a suitable format for usage in a file/folder name?

Find largest and smallest number in an array

FirstOrDefault returns NullReferenceException if no match is found

How to label each equation in align environment?

Solving a "communications link failure" with JDBC and MySQL

Are nested try/except blocks in Python a good programming practice?