Programs & Examples On #Nested statement

Execution failed for task ':app:compileDebugJavaWithJavac' Android Studio 3.1 Update

I solved it by deleting "/.idea/libraries" from project. Thanks

Lodash - difference between .extend() / .assign() and .merge()

If you want a deep copy without override while retaining the same obj reference

obj = _.assign(obj, _.merge(obj, [source]))

How do I style appcompat-v7 Toolbar like Theme.AppCompat.Light.DarkActionBar?

Edit: After updating to appcompat-v7:22.1.1 and using AppCompatActivity instead of ActionBarActivity my styles.xml looks like:

<style name="AppBaseTheme" parent="Theme.AppCompat.Light">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="theme">@style/ThemeOverlay.AppCompat.Dark.ActionBar</item>
</style>

Note: This means I am using a Toolbar provided by the framework (NOT included in an XML file).

This worked for me:
styles.xml file:

<style name="AppBaseTheme" parent="Theme.AppCompat.Light">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="windowActionBar">false</item>
    <item name="theme">@style/ThemeOverlay.AppCompat.Dark.ActionBar</item>
</style>

Update: A quote from Gabriele Mariotti's blog.

With the new Toolbar you can apply a style and a theme. They are different! The style is local to the Toolbar view, for example the background color. The app:theme is instead global to all ui elements inflated in the Toolbar, for example the color of the title and icons.

What is the difference between UNION and UNION ALL?

UNION - results in distinct records

while

UNION ALL - results in all the records including duplicates.

Both are blocking operators and hence I personally prefer using JOINS over Blocking Operators(UNION, INTERSECT, UNION ALL etc. ) anytime.

To illustrate why Union operation performs poorly in comparison to Union All checkout the following example.

CREATE TABLE #T1 (data VARCHAR(10))

INSERT INTO #T1
SELECT 'abc'
UNION ALL
SELECT 'bcd'
UNION ALL
SELECT 'cde'
UNION ALL
SELECT 'def'
UNION ALL
SELECT 'efg'


CREATE TABLE #T2 (data VARCHAR(10))

INSERT INTO #T2
SELECT 'abc'
UNION ALL
SELECT 'cde'
UNION ALL
SELECT 'efg'

enter image description here

Following are results of UNION ALL and UNION operations.

enter image description here

A UNION statement effectively does a SELECT DISTINCT on the results set. If you know that all the records returned are unique from your union, use UNION ALL instead, it gives faster results.

Using UNION results in Distinct Sort operations in the Execution Plan. Proof to prove this statement is shown below:

enter image description here

Already defined in .obj - no double inclusions

This is not a compiler error: the error is coming from the linker. After compilation, the linker will merge the object files resulting from the compilation of each of your translation units (.cpp files).

The linker finds out that you have the same symbol defined multiple times in different translation units, and complains about it (it is a violation of the One Definition Rule).

The reason is most certainly that main.cpp includes client.cpp, and both these files are individually processed by the compiler to produce two separate object files. Therefore, all the symbols defined in the client.cpp translation unit will be defined also in the main.cpp translation unit. This is one of the reasons why you do not usually #include .cpp files.

Put the definition of your class in a separate client.hpp file which does not contain also the definitions of the member functions of that class; then, let client.cpp and main.cpp include that file (I mean #include). Finally, leave in client.cpp the definitions of your class's member functions.

client.h

#ifndef SOCKET_CLIENT_CLASS
#define SOCKET_CLIENT_CLASS
#ifndef BOOST_ASIO_HPP
#include <boost/asio.hpp>
#endif

class SocketClient // Or whatever the name is...
{

// ...

    bool read(int, char*); // Or whatever the name is...

//  ...
};

#endif

client.cpp

#include "Client.h"

// ...

bool SocketClient::read(int, char*)
{
    // Implementation  goes here...
}

// ... (add the definitions for all other member functions)

main.h

#include <iostream>
#include <string>
#include <sstream>
#include <boost/asio.hpp>
#include <boost/thread/thread.hpp>
#include "client.h"
//              ^^ Notice this!

main.cpp

#include "main.h"

How to write UTF-8 in a CSV file

For python2 you can use this code before csv_writer.writerows(rows)
This code will NOT convert integers to utf-8 strings

def encode_rows_to_utf8(rows):
    encoded_rows = []
    for row in rows:
        encoded_row = []
        for value in row:
            if isinstance(value, basestring):
                value = unicode(value).encode("utf-8")
            encoded_row.append(value)
        encoded_rows.append(encoded_row)
    return encoded_rows

How to copy directory recursively in python and overwrite all?

My simple answer.

def get_files_tree(src="src_path"):
    req_files = []
    for r, d, files in os.walk(src):
        for file in files:
            src_file = os.path.join(r, file)
            src_file = src_file.replace('\\', '/')
            if src_file.endswith('.db'):
                continue
            req_files.append(src_file)

    return req_files
def copy_tree_force(src_path="",dest_path=""):
    """
    make sure that all the paths has correct slash characters.
    """
    for cf in get_files_tree(src=src_path):
        df= cf.replace(src_path, dest_path)
        if not os.path.exists(os.path.dirname(df)):
            os.makedirs(os.path.dirname(df))
        shutil.copy2(cf, df)

Install msi with msiexec in a Specific Directory

This one worked for me too

msiexec /i "msi path" INSTALLDIR="D:\myfolder" /q

I had tried two other iterations and both installed in the default C:\Program Files

INSTALLDIR="D:\myfolder" /q got it installed on the other drive.

How to type ":" ("colon") in regexp?

Be careful, - has a special meaning with regexp. In a [], you can put it without problem if it is placed at the end. In your case, ,-: is taken as from , to :.

Android emulator-5554 offline

From AVD manager list at the actions dropdown: Cold Boot Now

restarts it without all pain above.

Is there a way to ignore a single FindBugs warning?

The FindBugs initial approach involves XML configuration files aka filters. This is really less convenient than the PMD solution but FindBugs works on bytecode, not on the source code, so comments are obviously not an option. Example:

<Match>
   <Class name="com.mycompany.Foo" />
   <Method name="bar" />
   <Bug pattern="DLS_DEAD_STORE_OF_CLASS_LITERAL" />
</Match>

However, to solve this issue, FindBugs later introduced another solution based on annotations (see SuppressFBWarnings) that you can use at the class or at the method level (more convenient than XML in my opinion). Example (maybe not the best one but, well, it's just an example):

@edu.umd.cs.findbugs.annotations.SuppressFBWarnings(
    value="HE_EQUALS_USE_HASHCODE", 
    justification="I know what I'm doing")

Note that since FindBugs 3.0.0 SuppressWarnings has been deprecated in favor of @SuppressFBWarnings because of the name clash with Java's SuppressWarnings.

MVC Form not able to post List of objects

Your model is null because the way you're supplying the inputs to your form means the model binder has no way to distinguish between the elements. Right now, this code:

@foreach (var planVM in Model)
{
    @Html.Partial("_partialView", planVM)
}

is not supplying any kind of index to those items. So it would repeatedly generate HTML output like this:

<input type="hidden" name="yourmodelprefix.PlanID" />
<input type="hidden" name="yourmodelprefix.CurrentPlan" />
<input type="checkbox" name="yourmodelprefix.ShouldCompare" />

However, as you're wanting to bind to a collection, you need your form elements to be named with an index, such as:

<input type="hidden" name="yourmodelprefix[0].PlanID" />
<input type="hidden" name="yourmodelprefix[0].CurrentPlan" />
<input type="checkbox" name="yourmodelprefix[0].ShouldCompare" />
<input type="hidden" name="yourmodelprefix[1].PlanID" />
<input type="hidden" name="yourmodelprefix[1].CurrentPlan" />
<input type="checkbox" name="yourmodelprefix[1].ShouldCompare" />

That index is what enables the model binder to associate the separate pieces of data, allowing it to construct the correct model. So here's what I'd suggest you do to fix it. Rather than looping over your collection, using a partial view, leverage the power of templates instead. Here's the steps you'd need to follow:

  1. Create an EditorTemplates folder inside your view's current folder (e.g. if your view is Home\Index.cshtml, create the folder Home\EditorTemplates).
  2. Create a strongly-typed view in that directory with the name that matches your model. In your case that would be PlanCompareViewModel.cshtml.

Now, everything you have in your partial view wants to go in that template:

@model PlanCompareViewModel
<div>
    @Html.HiddenFor(p => p.PlanID)
    @Html.HiddenFor(p => p.CurrentPlan)
    @Html.CheckBoxFor(p => p.ShouldCompare)
   <input type="submit" value="Compare"/>
</div>

Finally, your parent view is simplified to this:

@model IEnumerable<PlanCompareViewModel>
@using (Html.BeginForm("ComparePlans", "Plans", FormMethod.Post, new { id = "compareForm" }))
{
<div>
    @Html.EditorForModel()
</div>
}

DisplayTemplates and EditorTemplates are smart enough to know when they are handling collections. That means they will automatically generate the correct names, including indices, for your form elements so that you can correctly model bind to a collection.

Is there a way to create key-value pairs in Bash script?

If you can use a simple delimiter, a very simple oneliner is this:

for i in a,b c_s,d ; do 
  KEY=${i%,*};
  VAL=${i#*,};
  echo $KEY" XX "$VAL;
done

Hereby i is filled with character sequences like "a,b" and "c_s,d". each separated by spaces. After the do we use parameter substitution to extract the part before the comma , and the part after it.

Remove duplicated rows using dplyr

For completeness’ sake, the following also works:

df %>% group_by(x) %>% filter (! duplicated(y))

However, I prefer the solution using distinct, and I suspect it’s faster, too.

Gradle - Error Could not find method implementation() for arguments [com.android.support:appcompat-v7:26.0.0]

Make sure your Gradle version is 3.*.* or higher before using "implementation".

Open the project level Gradle file under dependencies:

dependencies{
    classpath 'com.android.tools.build:gradle:3.1.2'
}

Open the 'gradle-wrapper.properties' file and set the distributionUrl:

distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip

or latest version.

Sync the project. I Hope this solves your problem.

JavaScript adding decimal numbers issue

Use toFixed to convert it to a string with some decimal places shaved off, and then convert it back to a number.

+(0.1 + 0.2).toFixed(12) // 0.3

It looks like IE's toFixed has some weird behavior, so if you need to support IE something like this might be better:

Math.round((0.1 + 0.2) * 1e12) / 1e12

How can I refresh or reload the JFrame?

You should use this code

this.setVisible(false); //this will close frame i.e. NewJFrame

new NewJFrame().setVisible(true); // Now this will open NewJFrame for you again and will also get refreshed 

Java: set timeout on a certain block of code?

If it is test code you want to time, then you can use the time attribute:

@Test(timeout = 1000)  
public void shouldTakeASecondOrLess()
{
}

If it is production code, there is no simple mechanism, and which solution you use depends upon whether you can alter the code to be timed or not.

If you can change the code being timed, then a simple approach is is to have your timed code remember it's start time, and periodically the current time against this. E.g.

long startTime = System.currentTimeMillis();
// .. do stuff ..
long elapsed = System.currentTimeMillis()-startTime;
if (elapsed>timeout)
   throw new RuntimeException("tiomeout");

If the code itself cannot check for timeout, you can execute the code on another thread, and wait for completion, or timeout.

    Callable<ResultType> run = new Callable<ResultType>()
    {
        @Override
        public ResultType call() throws Exception
        {
            // your code to be timed
        }
    };

    RunnableFuture future = new FutureTask(run);
    ExecutorService service = Executors.newSingleThreadExecutor();
    service.execute(future);
    ResultType result = null;
    try
    {
        result = future.get(1, TimeUnit.SECONDS);    // wait 1 second
    }
    catch (TimeoutException ex)
    {
        // timed out. Try to stop the code if possible.
        future.cancel(true);
    }
    service.shutdown();
}

Google Authenticator available as a public service?

The project is open source. I have not used it. But it's using a documented algorithm (noted in the RFC listed on the open source project page), and the authenticator implementations support multiple accounts.

The actual process is straightforward. The one time code is, essentially, a pseudo random number generator. A random number generator is a formula that once given a seed, or starting number, continues to create a stream of random numbers. Given a seed, while the numbers may be random to each other, the sequence itself is deterministic. So, once you have your device and the server "in sync" then the random numbers that the device creates, each time you hit the "next number button", will be the same, random, numbers the server expects.

A secure one time password system is more sophisticated than a random number generator, but the concept is similar. There are also other details to help keep the device and server in sync.

So, there's no need for someone else to host the authentication, like, say OAuth. Instead you need to implement that algorithm that is compatible with the apps that Google provides for the mobile devices. That software is (should be) available on the open source project.

Depending on your sophistication, you should have all you need to implement the server side of this process give the OSS project and the RFC. I do not know if there is a specific implementation for your server software (PHP, Java, .NET, etc.)

But, specifically, you don't need an offsite service to handle this.

How to import jquery using ES6 syntax?

Pika is a CDN that takes care of providing module versions of popular packages

<script type='module'>
    import * as $ from 'https://cdn.skypack.dev/jquery';

    // use it!
    $('#myDev').on('click', alert);
</script>

Skypack is Pika, so you could also use: import * as $ from 'https://cdn.pika.dev/jquery@^3.5.1';

Loading and parsing a JSON file with multiple JSON objects

for those stumbling upon this question: the python jsonlines library (much younger than this question) elegantly handles files with one json document per line. see https://jsonlines.readthedocs.io/

Check that Field Exists with MongoDB

db.<COLLECTION NAME>.find({ "<FIELD NAME>": { $exists: true, $ne: null } })

How do I add space between items in an ASP.NET RadioButtonList

<asp:RadioButtonList ID="rbn" runat="server" RepeatLayout="Table" RepeatColumns="2"
                        Width="100%" >
                        <asp:ListItem Text="1"></asp:ListItem>
                        <asp:ListItem Text="2"></asp:ListItem>
                        <asp:ListItem Text="3"></asp:ListItem>
                        <asp:ListItem Text="4"></asp:ListItem>
                    </asp:RadioButtonList>

What is the correct JSON content type?

There is no doubt that application/json is the best MIME type for a JSON response.

But I had some experience where I had to use application/x-javascript because of some compression issues. My hosting environment is shared hosting with GoDaddy. They do not allow me to change server configurations. I had added the following code to my web.config file for compressing responses.

<httpCompression>
    <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll"/>
    <dynamicTypes>
        <add mimeType="text/*" enabled="true"/>
        <add mimeType="message/*" enabled="true"/>
        <add mimeType="application/javascript" enabled="true"/>
        <add mimeType="*/*" enabled="false"/>
    </dynamicTypes>
    <staticTypes>
        <add mimeType="text/*" enabled="true"/>
        <add mimeType="message/*" enabled="true"/>
        <add mimeType="application/javascript" enabled="true"/>
        <add mimeType="*/*" enabled="false"/>
    </staticTypes>
</httpCompression>
<urlCompression doStaticCompression="true" doDynamicCompression="true"/>

By using this, the .aspx pages was compressed with g-zip but JSON responses were not. I added

<add mimeType="application/json" enabled="true"/>

in the static and dynamic types sections. But this does not compress JSON responses at all.

After that I removed this newly added type and added

<add mimeType="application/x-javascript" enabled="true"/>

in both the static and dynamic types sections, and changed the response type in

.ashx (asynchronous handler) to

application/x-javascript

And now I found that my JSON responses were compressed with g-zip. So I personally recommend to use

application/x-javascript

only if you want to compress your JSON responses on a shared hosting environment. Because in shared hosting, they do not allow you to change IIS configurations.

How to parse a query string into a NameValueCollection in .NET

    private void button1_Click( object sender, EventArgs e )
    {
        string s = @"p1=6&p2=7&p3=8";
        NameValueCollection nvc = new NameValueCollection();

        foreach ( string vp in Regex.Split( s, "&" ) )
        {
            string[] singlePair = Regex.Split( vp, "=" );
            if ( singlePair.Length == 2 )
            {
                nvc.Add( singlePair[ 0 ], singlePair[ 1 ] );    
            }    
        }
    }

Sql Query to list all views in an SQL Server 2005 database

Necromancing.

Since you said ALL views, technically, all answers to date are WRONG.
Here is how to get ALL views:

SELECT 
     sch.name AS view_schema 
    ,sysv.name AS view_name 
    ,ISNULL(sysm.definition, syssm.definition) AS view_definition 
    ,create_date 
    ,modify_date 
FROM sys.all_views AS sysv 

INNER JOIN sys.schemas AS sch 
    ON sch.schema_id = sysv.schema_id 

LEFT JOIN sys.sql_modules AS sysm 
    ON sysm.object_id = sysv.object_id 

LEFT JOIN sys.system_sql_modules AS syssm 
    ON syssm.object_id = sysv.object_id 

-- INNER JOIN sys.objects AS syso ON syso.object_id = sysv.object_id 

WHERE (1=1) 
AND (sysv.type = 'V') -- seems unnecessary, but who knows
-- AND sch.name = 'INFORMATION_SCHEMA' 
/*
AND sysv.is_ms_shipped = 0  
AND NOT EXISTS 
(
    SELECT * FROM sys.extended_properties AS syscrap
    WHERE syscrap.major_id = sysv.object_id
    AND syscrap.minor_id = 0 
    AND syscrap.class = 1 
    AND syscrap.name = N'microsoft_database_tools_support' 
)  
*/

ORDER BY 
     view_schema 
    ,view_name 

Format number as percent in MS SQL Server

took the challenge to solve this issue. comment number 5 (M.Ali) asked for --"The required answer is 97.36 % (not 0.97 %) .." so for that i'm attaching a photo who compare between post number 3 (sqluser) to my solution. (i'm using the postgre_sql on a mac)

enter image description here

Can you get a Windows (AD) username in PHP?

You could probably authenticate the user in Apache with mod_auth_kerb by requiring authenticated access to some files … I think that way, the username should also be available in PHP environment variables somewhere … probably best to check with <?php phpinfo(); ?> once you get it runnning.

Eclipse memory settings when getting "Java Heap Space" and "Out of Memory"

Tomcat in Eclipse does not use catalina.sh or bat. To setup memory for managed Tomcat use VM settings in server run configuration

How can I populate a select dropdown list from a JSON feed with AngularJS?

The proper way to do it is using the ng-options directive. The HTML would look like this.

<select ng-model="selectedTestAccount" 
        ng-options="item.Id as item.Name for item in testAccounts">
    <option value="">Select Account</option>
</select>

JavaScript:

angular.module('test', []).controller('DemoCtrl', function ($scope, $http) {
    $scope.selectedTestAccount = null;
    $scope.testAccounts = [];

    $http({
            method: 'GET',
            url: '/Admin/GetTestAccounts',
            data: { applicationId: 3 }
        }).success(function (result) {
        $scope.testAccounts = result;
    });
});

You'll also need to ensure angular is run on your html and that your module is loaded.

<html ng-app="test">
    <body ng-controller="DemoCtrl">
    ....
    </body>
</html>

Regex doesn't work in String.matches()

java's implementation of regexes try to match the whole string

that's different from perl regexes, which try to find a matching part

if you want to find a string with nothing but lower case characters, use the pattern [a-z]+

if you want to find a string containing at least one lower case character, use the pattern .*[a-z].*

How to get records randomly from the oracle database?

In summary, two ways were introduced

1) using order by DBMS_RANDOM.VALUE clause
2) using sample([%]) function

The first way has advantage in 'CORRECTNESS' which means you will never fail get result if it actually exists, while in the second way you may get no result even though it has cases satisfying the query condition since information is reduced during sampling.

The second way has advantage in 'EFFICIENT' which mean you will get result faster and give light load to your database. I was given an warning from DBA that my query using the first way gives loads to the database

You can choose one of two ways according to your interest!

How to install Hibernate Tools in Eclipse?

I'm running Eclipse Indigo 64 bit on Windows 7 64 bit and I kept getting missing dependency errors associated with Maven and other plugins using the JBoss Tools 3.3.X latest download. Here is the link.

So, I opted to only install Hibernate Tools with nothing else by typing in "hibernate" at the top of the install software dialog in eclipse. Only 4 items showed up, so that is all I installed. It worked fine with no problems. Here is the tutorial that I used to get it installed properly after several failed attempts.

I don't know if part of this was due to having a lot of plugins already installed or if this is the best solution or not, but I thought I'd share it with everyone.

Connection pooling options with JDBC: DBCP vs C3P0

my recommendation is

hikari > druid > UCP > c3p0 > DBCP

It's based on what I have tested - 20190202, in my local test environment(4GB mac/mysql in docker/pool minSize=1, maxSize=8), hikari can serve 1024 threads x 1024 times to get connections, average time for each thread to finish is 1 or 2 million seconds, while c3p0 can only serve 256 threads x 1024 times and average time for each thread is already 21 million seconds. (512 threads failed).

PIL image to array (numpy array to array) - Python

I highly recommend you use the tobytes function of the Image object. After some timing checks this is much more efficient.

def jpg_image_to_array(image_path):
  """
  Loads JPEG image into 3D Numpy array of shape 
  (width, height, channels)
  """
  with Image.open(image_path) as image:         
    im_arr = np.fromstring(image.tobytes(), dtype=np.uint8)
    im_arr = im_arr.reshape((image.size[1], image.size[0], 3))                                   
  return im_arr

The timings I ran on my laptop show

In [76]: %timeit np.fromstring(im.tobytes(), dtype=np.uint8)
1000 loops, best of 3: 230 µs per loop

In [77]: %timeit np.array(im.getdata(), dtype=np.uint8)
10 loops, best of 3: 114 ms per loop

```

How to change background color in android app

The best way using background with gradient as it does not increase app size of your app images are poison for android app so try to use it less instead of using one color as a background you can use multiple colors in one background. enter image description here enter image description here

enter image description hereenter image description here

How to create a vector of user defined size but with no predefined values?

With the constructor:

// create a vector with 20 integer elements
std::vector<int> arr(20);

for(int x = 0; x < 20; ++x)
   arr[x] = x;

Cannot set property 'innerHTML' of null

I have had the same problem and it turns out that the null error was because I had not saved the html I was working with.

If the element referred to has not been saved once the page is loaded is 'null', because the document does not contain it at the time of load. Using window.onload also helps debugging.

I hope this was useful to you.

Pass react component as props

Using this.props.children is the idiomatic way to pass instantiated components to a react component

const Label = props => <span>{props.children}</span>
const Tab = props => <div>{props.children}</div>
const Page = () => <Tab><Label>Foo</Label></Tab>

When you pass a component as a parameter directly, you pass it uninstantiated and instantiate it by retrieving it from the props. This is an idiomatic way of passing down component classes which will then be instantiated by the components down the tree (e.g. if a component uses custom styles on a tag, but it wants to let the consumer choose whether that tag is a div or span):

const Label = props => <span>{props.children}</span>
const Button = props => {
    const Inner = props.inner; // Note: variable name _must_ start with a capital letter 
    return <button><Inner>Foo</Inner></button>
}
const Page = () => <Button inner={Label}/>

If what you want to do is to pass a children-like parameter as a prop, you can do that:

const Label = props => <span>{props.content}</span>
const Tab = props => <div>{props.content}</div>
const Page = () => <Tab content={<Label content='Foo' />} />

After all, properties in React are just regular JavaScript object properties and can hold any value - be it a string, function or a complex object.

What is the difference between List and ArrayList?

There's no difference between list implementations in both of your examples. There's however a difference in a way you can further use variable myList in your code.

When you define your list as:

List myList = new ArrayList();

you can only call methods and reference members that are defined in the List interface. If you define it as:

ArrayList myList = new ArrayList();

you'll be able to invoke ArrayList-specific methods and use ArrayList-specific members in addition to those whose definitions are inherited from List.

Nevertheless, when you call a method of a List interface in the first example, which was implemented in ArrayList, the method from ArrayList will be called (because the List interface doesn't implement any methods).

That's called polymorphism. You can read up on it.

write newline into a file

if(!file3.exists()){
    file3.createNewFile();
}
FileOutputStream fop=new FileOutputStream(file3,true);
if(nodeValue!=null) fop.write(nodeValue.getBytes());

fop.write("\n".getBytes());

fop.flush();
fop.close();

You need to add a newline at the end of each write.

What does on_delete do on Django models?

Here is answer for your question that says: why we use on_delete?

When an object referenced by a ForeignKey is deleted, Django by default emulates the behavior of the SQL constraint ON DELETE CASCADE and also deletes the object containing the ForeignKey. This behavior can be overridden by specifying the on_delete argument. For example, if you have a nullable ForeignKey and you want it to be set null when the referenced object is deleted:

user = models.ForeignKey(User, blank=True, null=True, on_delete=models.SET_NULL)

The possible values for on_delete are found in django.db.models:

CASCADE: Cascade deletes; the default.

PROTECT: Prevent deletion of the referenced object by raising ProtectedError, a subclass of django.db.IntegrityError.

SET_NULL: Set the ForeignKey null; this is only possible if null is True.

SET_DEFAULT: Set the ForeignKey to its default value; a default for the ForeignKey must be set.

How to skip over an element in .map()?

Here is a updated version of the code provided by @theprtk. It is a cleaned up a little to show the generalized version whilst having an example.

Note: I'd add this as a comment to his post but I don't have enough reputation yet

/**
 * @see http://clojure.com/blog/2012/05/15/anatomy-of-reducer.html
 * @description functions that transform reducing functions
 */
const transduce = {
  /** a generic map() that can take a reducing() & return another reducing() */
  map: changeInput => reducing => (acc, input) =>
    reducing(acc, changeInput(input)),
  /** a generic filter() that can take a reducing() & return */
  filter: predicate => reducing => (acc, input) =>
    predicate(input) ? reducing(acc, input) : acc,
  /**
   * a composing() that can take an infinite # transducers to operate on
   *  reducing functions to compose a computed accumulator without ever creating
   *  that intermediate array
   */
  compose: (...args) => x => {
    const fns = args;
    var i = fns.length;
    while (i--) x = fns[i].call(this, x);
    return x;
  },
};

const example = {
  data: [{ src: 'file.html' }, { src: 'file.txt' }, { src: 'file.json' }],
  /** note: `[1,2,3].reduce(concat, [])` -> `[1,2,3]` */
  concat: (acc, input) => acc.concat([input]),
  getSrc: x => x.src,
  filterJson: x => x.src.split('.').pop() !== 'json',
};

/** step 1: create a reducing() that can be passed into `reduce` */
const reduceFn = example.concat;
/** step 2: transforming your reducing function by mapping */
const mapFn = transduce.map(example.getSrc);
/** step 3: create your filter() that operates on an input */
const filterFn = transduce.filter(example.filterJson);
/** step 4: aggregate your transformations */
const composeFn = transduce.compose(
  filterFn,
  mapFn,
  transduce.map(x => x.toUpperCase() + '!'), // new mapping()
);

/**
 * Expected example output
 *  Note: each is wrapped in `example.data.reduce(x, [])`
 *  1: ['file.html', 'file.txt', 'file.json']
 *  2:  ['file.html', 'file.txt']
 *  3: ['FILE.HTML!', 'FILE.TXT!']
 */
const exampleFns = {
  transducers: [
    mapFn(reduceFn),
    filterFn(mapFn(reduceFn)),
    composeFn(reduceFn),
  ],
  raw: [
    (acc, x) => acc.concat([x.src]),
    (acc, x) => acc.concat(x.src.split('.').pop() !== 'json' ? [x.src] : []),
    (acc, x) => acc.concat(x.src.split('.').pop() !== 'json' ? [x.src.toUpperCase() + '!'] : []),
  ],
};
const execExample = (currentValue, index) =>
  console.log('Example ' + index, example.data.reduce(currentValue, []));

exampleFns.raw.forEach(execExample);
exampleFns.transducers.forEach(execExample);

Get all table names of a particular database by SQL query?

For Mysql you can do simple. SHOW TABLES;

Node.js check if file exists

Edit: Since node v10.0.0we could use fs.promises.access(...)

Example async code that checks if file exists:

async function checkFileExists(file) {
  return fs.promises.access(file, fs.constants.F_OK)
           .then(() => true)
           .catch(() => false)
}

An alternative for stat might be using the new fs.access(...):

minified short promise function for checking:

s => new Promise(r=>fs.access(s, fs.constants.F_OK, e => r(!e)))

Sample usage:

let checkFileExists = s => new Promise(r=>fs.access(s, fs.constants.F_OK, e => r(!e)))
checkFileExists("Some File Location")
  .then(bool => console.log(´file exists: ${bool}´))

expanded Promise way:

// returns a promise which resolves true if file exists:
function checkFileExists(filepath){
  return new Promise((resolve, reject) => {
    fs.access(filepath, fs.constants.F_OK, error => {
      resolve(!error);
    });
  });
}

or if you wanna do it synchronously:

function checkFileExistsSync(filepath){
  let flag = true;
  try{
    fs.accessSync(filepath, fs.constants.F_OK);
  }catch(e){
    flag = false;
  }
  return flag;
}

JavaScript Object Id

No, objects don't have a built in identifier, though you can add one by modifying the object prototype. Here's an example of how you might do that:

(function() {
    var id = 0;

    function generateId() { return id++; };

    Object.prototype.id = function() {
        var newId = generateId();

        this.id = function() { return newId; };

        return newId;
    };
})();

That said, in general modifying the object prototype is considered very bad practice. I would instead recommend that you manually assign an id to objects as needed or use a touch function as others have suggested.

How do I define and use an ENUM in Objective-C?

With current projects you may want to use the NS_ENUM() or NS_OPTIONS() macros.

typedef NS_ENUM(NSUInteger, PlayerState) {
        PLAYER_OFF,
        PLAYER_PLAYING,
        PLAYER_PAUSED
    };

Markdown and including multiple files

Asciidoc is actually a markdown on steroids. Overall, Asciidoc and Markdown will look very similar and it is rather easy to switch. A huge benefit of Asciidoc over markdown is that it supports includes already, for other Asciidoc files but also for any format you like. You can even partly include files based on line numbers or tags inside your included files.

Including other files is really a life saver when you write docs.

You can for instance have an asciidoc file with such content:

// [source,perl]
// ----
// include::script.pl[]
// ----

and maintain your sample in script.pl

And I am sure you will wonder so yes, Github also supports asciidoc.

What is the correct way to create a single-instance WPF application?

Here is an example that allows you to have a single instance of an application. When any new instances load, they pass their arguments to the main instance that is running.

public partial class App : Application
{
    private static Mutex SingleMutex;
    public static uint MessageId;

    private void Application_Startup(object sender, StartupEventArgs e)
    {
        IntPtr Result;
        IntPtr SendOk;
        Win32.COPYDATASTRUCT CopyData;
        string[] Args;
        IntPtr CopyDataMem;
        bool AllowMultipleInstances = false;

        Args = Environment.GetCommandLineArgs();

        // TODO: Replace {00000000-0000-0000-0000-000000000000} with your application's GUID
        MessageId   = Win32.RegisterWindowMessage("{00000000-0000-0000-0000-000000000000}");
        SingleMutex = new Mutex(false, "AppName");

        if ((AllowMultipleInstances) || (!AllowMultipleInstances && SingleMutex.WaitOne(1, true)))
        {
            new Main();
        }
        else if (Args.Length > 1)
        {
            foreach (Process Proc in Process.GetProcesses())
            {
                SendOk = Win32.SendMessageTimeout(Proc.MainWindowHandle, MessageId, IntPtr.Zero, IntPtr.Zero,
                    Win32.SendMessageTimeoutFlags.SMTO_BLOCK | Win32.SendMessageTimeoutFlags.SMTO_ABORTIFHUNG,
                    2000, out Result);

                if (SendOk == IntPtr.Zero)
                    continue;
                if ((uint)Result != MessageId)
                    continue;

                CopyDataMem = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(Win32.COPYDATASTRUCT)));

                CopyData.dwData = IntPtr.Zero;
                CopyData.cbData = Args[1].Length*2;
                CopyData.lpData = Marshal.StringToHGlobalUni(Args[1]);

                Marshal.StructureToPtr(CopyData, CopyDataMem, false);

                Win32.SendMessageTimeout(Proc.MainWindowHandle, Win32.WM_COPYDATA, IntPtr.Zero, CopyDataMem,
                    Win32.SendMessageTimeoutFlags.SMTO_BLOCK | Win32.SendMessageTimeoutFlags.SMTO_ABORTIFHUNG,
                    5000, out Result);

                Marshal.FreeHGlobal(CopyData.lpData);
                Marshal.FreeHGlobal(CopyDataMem);
            }

            Shutdown(0);
        }
    }
}

public partial class Main : Window
{
    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        HwndSource Source;

        Source = HwndSource.FromHwnd(new WindowInteropHelper(this).Handle);
        Source.AddHook(new HwndSourceHook(Window_Proc));
    }

    private IntPtr Window_Proc(IntPtr hWnd, int Msg, IntPtr wParam, IntPtr lParam, ref bool Handled)
    {
        Win32.COPYDATASTRUCT CopyData;
        string Path;

        if (Msg == Win32.WM_COPYDATA)
        {
            CopyData = (Win32.COPYDATASTRUCT)Marshal.PtrToStructure(lParam, typeof(Win32.COPYDATASTRUCT));
            Path = Marshal.PtrToStringUni(CopyData.lpData, CopyData.cbData / 2);

            if (WindowState == WindowState.Minimized)
            {
                // Restore window from tray
            }

            // Do whatever we want with information

            Activate();
            Focus();
        }

        if (Msg == App.MessageId)
        {
            Handled = true;
            return new IntPtr(App.MessageId);
        }

        return IntPtr.Zero;
    }
}

public class Win32
{
    public const uint WM_COPYDATA = 0x004A;

    public struct COPYDATASTRUCT
    {
        public IntPtr dwData;
        public int    cbData;
        public IntPtr lpData;
    }

    [Flags]
    public enum SendMessageTimeoutFlags : uint
    {
        SMTO_NORMAL             = 0x0000,
        SMTO_BLOCK              = 0x0001,
        SMTO_ABORTIFHUNG        = 0x0002,
        SMTO_NOTIMEOUTIFNOTHUNG = 0x0008
    }

    [DllImport("user32.dll", SetLastError=true, CharSet=CharSet.Auto)]
    public static extern uint RegisterWindowMessage(string lpString);
    [DllImport("user32.dll")]
    public static extern IntPtr SendMessageTimeout(
        IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam,
        SendMessageTimeoutFlags fuFlags, uint uTimeout, out IntPtr lpdwResult);
}

Delete all Duplicate Rows except for One in MySQL?

Editor warning: This solution is computationally inefficient and may bring down your connection for a large table.

NB - You need to do this first on a test copy of your table!

When I did it, I found that unless I also included AND n1.id <> n2.id, it deleted every row in the table.

  1. If you want to keep the row with the lowest id value:

    DELETE n1 FROM names n1, names n2 WHERE n1.id > n2.id AND n1.name = n2.name
    
  2. If you want to keep the row with the highest id value:

    DELETE n1 FROM names n1, names n2 WHERE n1.id < n2.id AND n1.name = n2.name
    

I used this method in MySQL 5.1

Not sure about other versions.


Update: Since people Googling for removing duplicates end up here
Although the OP's question is about DELETE, please be advised that using INSERT and DISTINCT is much faster. For a database with 8 million rows, the below query took 13 minutes, while using DELETE, it took more than 2 hours and yet didn't complete.

INSERT INTO tempTableName(cellId,attributeId,entityRowId,value)
    SELECT DISTINCT cellId,attributeId,entityRowId,value
    FROM tableName;

Server Document Root Path in PHP

$files = glob($_SERVER["DOCUMENT_ROOT"]."/myFolder/*");

How to find longest string in the table column data

SELECT CITY,LENGTH(CITY) FROM STATION GROUP BY CITY ORDER BY LENGTH(CITY) ASC LIMIT 1;
SELECT CITY,LENGTH(CITY) FROM STATION GROUP BY CITY ORDER BY LENGTH(CITY) DESC LIMIT 1;

How to hide the keyboard when I press return key in a UITextField?

Ok, I think for a novice things might be a bit confusing. I think the correct answer is a mix of all the above, at least in Swift4.

Either create an extension or use the ViewController in which you'd like to use this but make sure to implement UITextFieldDelegate. For reusability's sake I found it easier to use an extension:

extension UIViewController : UITextFieldDelegate {
    ...
}

but the alternative works as well:

class MyViewController: UIViewController {
    ...
}

Add the method textFieldShouldReturn (depending on your previous option, either in the extension or in your ViewController)

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    return textField.endEditing(false)
}

In your viewDidLoad method, set the textfield's delegate to self

@IBOutlet weak var myTextField: UITextField!
...

override func viewDidLoad() {
    ..
    myTextField.delegte = self;
    ..
}

That should be all. Now, when you press return the textFieldShouldReturn should be called.

Number of visitors on a specific page

If you want to know the number of visitors (as is titled in the question) and not the number of pageviews, then you'll need to create a custom report.

 

Terminology


Google Analytics has changed the terminology they use within the reports. Now, visits is named "sessions" and unique visitors is named "users."

User - A unique person who has visited your website. Users may visit your website multiple times, and they will only be counted once.

Session - The number of different times that a visitor came to your site.

Pageviews - The total number of pages that a user has accessed.

 

Creating a Custom Report


  1. To create a custom report, click on the "Customization" item in the left navigation menu, and then click on "Custom Reports".

customization item expanded in navigation menu

  1. The "Create Custom Report" page will open.
  2. Enter a name for your report.
  3. In the "Metric Groups" section, enter either "Users" or "Sessions" depending on what information you want to collect (see Terminology, above).
  4. In the "Dimension Drilldowns" section, enter "Page".
  5. Under "Filters" enter the individual page (exact) or group of pages (using regex) that you would like to see the data for. enter image description here
  6. Save the report and run it.

How to restrict the selectable date ranges in Bootstrap Datepicker?

Another possibility is to use the options with data attributes, like this(minimum date 1 week before):

<input class='datepicker' data-date-start-date="-1w">

More info: http://bootstrap-datepicker.readthedocs.io/en/latest/options.html

How can I undo a `git commit` locally and on a remote after `git push`

You can do an interactive rebase:

git rebase -i <commit>

This will bring up your default editor. Just delete the line containing the commit you want to remove to delete that commit.

You will, of course, need access to the remote repository to apply this change there too.

See this question: Git: removing selected commits from repository

How do you close/hide the Android soft keyboard using Java?

Here are the best solutions

Solution 1) Set the inputType to “text”

<EditText
android:id="@+id/my_edit_text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:hint="Tap here to type"
android:inputType="text" />

This can also be done programmatically via. the method setInputType() (inherited from TextView).

EditText editText = (EditText) findViewById(R.id.my_edit_text);
editText.setRawInputType(InputType.TYPE_CLASS_TEXT | 
InputType.TYPE_TEXT_VARIATION_NORMAL);

Solution 2) Use the InputMethodManager.hideSoftInputFromWindow()

InputMethodManager imm = 
(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(myEditText.getWindowToken(), 0);

or

InputMethodManager imm = (InputMethodManager) 
getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(myEditText.getWindowToken(), 
InputMethodManager.HIDE_NOT_ALWAYS);

VBA for filtering columns

Here's a different approach. The heart of it was created by turning on the Macro Recorder and filtering the columns per your specifications. Then there's a bit of code to copy the results. It will run faster than looping through each row and column:

Sub FilterAndCopy()
Dim LastRow As Long

Sheets("Sheet2").UsedRange.Offset(0).ClearContents
With Worksheets("Sheet1")
    .Range("$A:$E").AutoFilter
    .Range("$A:$E").AutoFilter field:=1, Criteria1:="#N/A"
    .Range("$A:$E").AutoFilter field:=2, Criteria1:="=String1", Operator:=xlOr, Criteria2:="=string2"
    .Range("$A:$E").AutoFilter field:=3, Criteria1:=">0"
    .Range("$A:$E").AutoFilter field:=5, Criteria1:="Number"
    LastRow = .Range("A" & .Rows.Count).End(xlUp).Row
    .Range("A1:A" & LastRow).SpecialCells(xlCellTypeVisible).EntireRow.Copy _
            Destination:=Sheets("Sheet2").Range("A1")
End With
End Sub

As a side note, your code has more loops and counter variables than necessary. You wouldn't need to loop through the columns, just through the rows. You'd then check the various cells of interest in that row, much like you did.

Android SDK installation doesn't find JDK

Yeah install the 32 bit version of the Java SE SDK (or any of the combinations). That should help solve your problem.

jQuery: Count number of list elements?

Try:

$("#mylist li").length

Just curious: why do you need to know the size? Can't you just use:

$("#mylist").append("<li>New list item</li>");

?

Permutations between two lists of unequal length

The simplest way is to use itertools.product:

a = ["foo", "melon"]
b = [True, False]
c = list(itertools.product(a, b))
>> [("foo", True), ("foo", False), ("melon", True), ("melon", False)]

Installation error: INSTALL_FAILED_OLDER_SDK

Received the same error , the problem was difference in the version of Android SDK which AVD was using and the version in AndroidManifest file. I could solve it by correcting the

android:minSdkVersion="16"

to match with AVD.

Send Outlook Email Via Python?

import win32com.client as win32
outlook = win32.Dispatch('outlook.application')
mail = outlook.CreateItem(0)
mail.To = 'To address'
mail.Subject = 'Message subject'
mail.Body = 'Message body'
mail.HTMLBody = '<h2>HTML Message body</h2>' #this field is optional

# To attach a file to the email (optional):
attachment  = "Path to the attachment"
mail.Attachments.Add(attachment)

mail.Send()

Will use your local outlook account to send.

Note if you are trying to do something not mentioned above, look at the COM docs properties/methods: https://msdn.microsoft.com/en-us/vba/outlook-vba/articles/mailitem-object-outlook. In the code above, mail is a MailItem Object.

Change class on mouseover in directive

I have run into problems in the past with IE and the css:hover selector so the approach that I have taken, is to use a custom directive.

.directive('hoverClass', function () {
    return {
        restrict: 'A',
        scope: {
            hoverClass: '@'
        },
        link: function (scope, element) {
            element.on('mouseenter', function() {
                element.addClass(scope.hoverClass);
            });
            element.on('mouseleave', function() {
                element.removeClass(scope.hoverClass);
            });
        }
    };
})

then on the element itself you can add the directive with the class names that you want enabled when the mouse is over the the element for example:

<li data-ng-repeat="item in social" hover-class="hover tint" class="social-{{item.name}}" ng-mouseover="hoverItem(true);" ng-mouseout="hoverItem(false);"
                index="{{$index}}"><i class="{{item.icon}}"
                box="course-{{$index}}"></i></li>

This should add the class hover and tint when the mouse is over the element and doesn't run the risk of a scope variable name collision. I haven't tested but the mouseenter and mouseleave events should still bubble up to the containing element so in the given scenario the following should still work

<div hover-class="hover" data-courseoverview data-ng-repeat="course in courses | orderBy:sortOrder | filter:search"
 data-ng-controller ="CourseItemController"
 data-ng-class="{ selected: isSelected }">

providing of course that the li's are infact children of the parent div

Why does an SSH remote command get fewer environment variables then when run manually?

Just export the environment variables you want above the check for a non-interactive shell in ~/.bashrc.

How to create relationships in MySQL

One of the rules you have to know is that the table column you want to reference to has to be with the same data type as The referencing table . 2 if you decide to use mysql you have to use InnoDB Engine because according to your question that’s the engine which supports what you want to achieve in mysql .

Bellow is the code try it though the first people to answer this question they 100% provided great answers and please consider them all .

CREATE TABLE accounts(
    account_id INT NOT NULL AUTO_INCREMENT,
    customer_id INT( 4 ) NOT NULL ,
    account_type ENUM( 'savings', 'credit' ) NOT NULL,
    balance FLOAT( 9 ) NOT NULL,
    PRIMARY KEY (account_id)
)ENGINE=InnoDB;

CREATE TABLE customers(
    customer_id INT NOT NULL AUTO_INCREMENT,
    name VARCHAR(20) NOT NULL,
    address VARCHAR(20) NOT NULL,
    city VARCHAR(20) NOT NULL,
    state VARCHAR(20) NOT NULL,
     PRIMARY KEY ( account_id ), 
FOREIGN KEY (customer_id) REFERENCES customers(customer_id) 
)ENGINE=InnoDB; 

http://localhost/ not working on Windows 7. What's the problem?

It sounds like you have no web server running at all anywhere.

Have you tried enabling IIS and using it to display a basic html file first?

Programs & Features -> Turn Windows Features On/Off -> Internet Information Servcies

Then, place your html file in C:\inetpub\wwwroot\index.html and browse to http://localhost.

Once this works, try to get WAMP/php working. Be careful of port conflicts.

How to use hex() without 0x in Python?

You can simply write

hex(x)[2:]

to get the first two characters removed.

Rename all files in directory from $filename_h to $filename_half?

for i in *_h.png ; do
  mv $i `echo "$i"|awk -F'.' '{print $1"alf."$2}'`
done

Evaluate empty or null JSTL c tags

In this step I have Set the variable first:

<c:set var="structureId" value="<%=article.getStructureId()%>" scope="request"></c:set>

In this step I have checked the variable empty or not:

 <c:if test="${not empty structureId }">
    <a href="javascript:void(0);">Change Design</a>
 </c:if>

ENOENT, no such file or directory

I believe the previous answer is the correct answer to this problem but I was getting this error when I tried installing npm package (see below) :

enter image description here

The fix for me was : npm init --yes

enter image description here

jquery ui Dialog: cannot call methods on dialog prior to initialization

I simply had to add the ScriptManager to the page. Issue resolved.

Laravel back button

I know this is an oldish question but I found it whilst looking for the same solution. The solution above doesn't appear to work in Laravel 4, you can however use this now:

<a href="{{ URL::previous() }}">Go Back</a>

Hope this helps people who look for this feature in L4

(Source: https://github.com/laravel/framework/pull/501/commits)

How to use pagination on HTML tables?

For me, best and simplest way, Bootply http://www.bootply.com/lxa0FF9yhw#

First include Bootstrap to your project

Then include javascript file in which you write this code:

    $.fn.pageMe = function(opts){
    var $this = this,
        defaults = {
            perPage: 7,
            showPrevNext: false,
            hidePageNumbers: false
        },
        settings = $.extend(defaults, opts);

    var listElement = $this;
    var perPage = settings.perPage; 
    var children = listElement.children();
    var pager = $('.pager');

    if (typeof settings.childSelector!="undefined") {
        children = listElement.find(settings.childSelector);
    }

    if (typeof settings.pagerSelector!="undefined") {
        pager = $(settings.pagerSelector);
    }

    var numItems = children.size();
    var numPages = Math.ceil(numItems/perPage);

    pager.data("curr",0);

    if (settings.showPrevNext){
        $('<li><a href="#" class="prev_link">«</a></li>').appendTo(pager);
    }

    var curr = 0;
    while(numPages > curr && (settings.hidePageNumbers==false)){
        $('<li><a href="#" class="page_link">'+(curr+1)+'</a></li>').appendTo(pager);
        curr++;
    }

    if (settings.showPrevNext){
        $('<li><a href="#" class="next_link">»</a></li>').appendTo(pager);
    }

    pager.find('.page_link:first').addClass('active');
    pager.find('.prev_link').hide();
    if (numPages<=1) {
        pager.find('.next_link').hide();
    }
    pager.children().eq(1).addClass("active");

    children.hide();
    children.slice(0, perPage).show();

    pager.find('li .page_link').click(function(){
        var clickedPage = $(this).html().valueOf()-1;
        goTo(clickedPage,perPage);
        return false;
    });
    pager.find('li .prev_link').click(function(){
        previous();
        return false;
    });
    pager.find('li .next_link').click(function(){
        next();
        return false;
    });

    function previous(){
        var goToPage = parseInt(pager.data("curr")) - 1;
        goTo(goToPage);
    }

    function next(){
        goToPage = parseInt(pager.data("curr")) + 1;
        goTo(goToPage);
    }

    function goTo(page){
        var startAt = page * perPage,
            endOn = startAt + perPage;

        children.css('display','none').slice(startAt, endOn).show();

        if (page>=1) {
            pager.find('.prev_link').show();
        }
        else {
            pager.find('.prev_link').hide();
        }

        if (page<(numPages-1)) {
            pager.find('.next_link').show();
        }
        else {
            pager.find('.next_link').hide();
        }

        pager.data("curr",page);
        pager.children().removeClass("active");
        pager.children().eq(page+1).addClass("active");

    }
};

You need to give an id to the tbody of your table and to add a 'div' after the table for the pagination

     <table class="table" id="myTable">
            <thead>
                <tr>
                    <th>...</th>
                </tr>
            </thead>
            <tbody id="myTableBody">
            </tbody>
       </table>
       <div class="col-md-12 text-center">
           <ul class="pagination pagination-lg pager" id="myPager"></ul>
       </div>

When your table's data is loaded, just call this

$('#myTableBody').pageMe({pagerSelector:'#myPager',showPrevNext:true,hidePageNumbers:false,perPage:4});

where the 'perPage' value is to set how many elements per page you want to have.

@AspectJ pointcut for all methods of a class with specific annotation

The simplest way seems to be :

@Around("execution(@MyHandling * com.exemple.YourService.*(..))")
public Object aroundServiceMethodAdvice(final ProceedingJoinPoint pjp)
   throws Throwable {
   // perform actions before

   return pjp.proceed();

   // perform actions after
}

It will intercept execution of all methods specifically annotated with '@MyHandling' in 'YourService' class. To intercept all methods without exception, just put the annotation directly on the class.

No matter of the private / public scope here, but keep in mind that spring-aop cannot use aspect for method calls in same instance (typically private ones), because it doesn't use the proxy class in this case.

We use @Around advice here, but it's basically the same syntax with @Before, @After or any advice.

By the way, @MyHandling annotation must be configured like this :

@Retention(RetentionPolicy.RUNTIME)
@Target( { ElementType.METHOD, ElementType.TYPE })
public @interface MyHandling {

}

Is there a way to retrieve the view definition from a SQL Server using plain ADO?

Which version of SQL Server?

For SQL Server 2005 and later, you can obtain the SQL script used to create the view like this:

select definition
from sys.objects     o
join sys.sql_modules m on m.object_id = o.object_id
where o.object_id = object_id( 'dbo.MyView')
  and o.type      = 'V'

This returns a single row containing the script used to create/alter the view.

Other columns in the table tell about about options in place at the time the view was compiled.

Caveats

  • If the view was last modified with ALTER VIEW, then the script will be an ALTER VIEW statement rather than a CREATE VIEW statement.

  • The script reflects the name as it was created. The only time it gets updated is if you execute ALTER VIEW, or drop and recreate the view with CREATE VIEW. If the view has been renamed (e.g., via sp_rename) or ownership has been transferred to a different schema, the script you get back will reflect the original CREATE/ALTER VIEW statement: it will not reflect the objects current name.

  • Some tools truncate the output. For example, the MS-SQL command line tool sqlcmd.exe truncates the data at 255 chars. You can pass the parameter -y N to get the result with N chars.

How to add a TextView to a LinearLayout dynamically in Android?

I customized more @Suragch code. My output looks

enter image description here

I wrote a method to stop code redundancy.

public TextView createATextView(int layout_widh, int layout_height, int align,
        String text, int fontSize, int margin, int padding) {

    TextView textView_item_name = new TextView(this);

    // LayoutParams layoutParams = new LayoutParams(
    // LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    // layoutParams.gravity = Gravity.LEFT;
    RelativeLayout.LayoutParams _params = new RelativeLayout.LayoutParams(
            layout_widh, layout_height);

    _params.setMargins(margin, margin, margin, margin);
    _params.addRule(align);
    textView_item_name.setLayoutParams(_params);

    textView_item_name.setText(text);
    textView_item_name.setTextSize(TypedValue.COMPLEX_UNIT_SP, fontSize);
    textView_item_name.setTextColor(Color.parseColor("#000000"));
    // textView1.setBackgroundColor(0xff66ff66); // hex color 0xAARRGGBB
    textView_item_name.setPadding(padding, padding, padding, padding);

    return textView_item_name;

}

It can be called like

createATextView(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT, RelativeLayout.ALIGN_PARENT_RIGHT,
            subTotal.toString(), 20, 10, 20);

Now you can add this to a RelativeLayout dynamically. LinearLayout is also same, just add a orientation.

    RelativeLayout primary_layout = new RelativeLayout(this);

    LayoutParams layoutParam = new LayoutParams(LayoutParams.MATCH_PARENT,
            LayoutParams.MATCH_PARENT);

    primary_layout.setLayoutParams(layoutParam);

    // FOR LINEAR LAYOUT SET ORIENTATION
    // primary_layout.setOrientation(LinearLayout.HORIZONTAL);

    // FOR BACKGROUND COLOR 
    primary_layout.setBackgroundColor(0xff99ccff);

    primary_layout.addView(createATextView(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT, RelativeLayout.ALIGN_LEFT, list[i],
            20, 10, 20));
    primary_layout.addView(createATextView(LayoutParams.WRAP_CONTENT,
            LayoutParams.WRAP_CONTENT, RelativeLayout.ALIGN_PARENT_RIGHT,
            subTotal.toString(), 20, 10, 20));

How to run composer from anywhere?

composer.phar can be ran on its own, no need to prefix it with php. This should solve your problem (being in the difference of bash's $PATH and php's include_path).

Date validation with ASP.NET validator

Best option would be

Add a compare validator to the web form. Set its controlToValidate. Set its Type property to Date. Set its operator property to DataTypeCheck eg:

<asp:CompareValidator
    id="dateValidator" runat="server" 
    Type="Date"
    Operator="DataTypeCheck"
    ControlToValidate="txtDatecompleted" 
    ErrorMessage="Please enter a valid date.">
</asp:CompareValidator>

jQuery checkbox event handling

Use the change event.

$('#myform :checkbox').change(function() {
    // this represents the checkbox that was checked
    // do something with it
});

Modify a Column's Type in sqlite3

SQLite doesn't support removing or modifying columns, apparently. But do remember that column data types aren't rigid in SQLite, either.

See also:

What is the difference between And and AndAlso in VB.NET?

If Bool1 And Bool2 Then

Evaluates both Bool1 and Bool2

If Bool1 AndAlso Bool2 Then

Evaluates Bool2 if and only if Bool1 is true.

is there any PHP function for open page in new tab

This is a trick,

function OpenInNewTab(url) {

  var win = window.open(url, '_blank');
  win.focus();
}

In most cases, this should happen directly in the onclick handler for the link to prevent pop-up blockers, and the default "new window" behavior. You could do it this way, or by adding an event listener to your DOM object.

<div onclick="OpenInNewTab();">Something To Click On</div>

Set textbox to readonly and background color to grey in jquery

Why don't you place the account number in a div. Style it as you please and then have a hidden input in the form that also contains the account number. Then when the form gets submitted, the value should come through and not be null.

'numpy.float64' object is not iterable

numpy.linspace() gives you a one-dimensional NumPy array. For example:

>>> my_array = numpy.linspace(1, 10, 10)
>>> my_array
array([  1.,   2.,   3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.])

Therefore:

for index,point in my_array

cannot work. You would need some kind of two-dimensional array with two elements in the second dimension:

>>> two_d = numpy.array([[1, 2], [4, 5]])
>>> two_d
array([[1, 2], [4, 5]])

Now you can do this:

>>> for x, y in two_d:
    print(x, y)

1 2
4 5

Determine a user's timezone

First, understand that time zone detection in JavaScript is imperfect. You can get the local time zone offset for a particular date and time using getTimezoneOffset on an instance of the Date object, but that's not quite the same as a full IANA time zone like America/Los_Angeles.

There are some options that can work though:

_x000D_
_x000D_
const tzid = Intl.DateTimeFormat().resolvedOptions().timeZone;
console.log(tzid);
_x000D_
_x000D_
_x000D_

The result is a string containing the IANA time zone setting of the computer where the code is running.

Supported environments are listed in the Intl compatibility table. Expand the DateTimeFormat section, and look at the feature named resolvedOptions().timeZone defaults to the host environment.

  • Some libraries, such as Luxon use this API to determine the time zone through functions like luxon.Settings.defaultZoneName.

  • If you need to support an wider set of environments, such as older web browsers, you can use a library to make an educated guess at the time zone. They work by first trying the Intl API if it's available, and when it's not available, they interrogate the getTimezoneOffset function of the Date object, for several different points in time, using the results to choose an appropriate time zone from an internal data set.

    Both jsTimezoneDetect and moment-timezone have this functionality.

      // using jsTimeZoneDetect
      var tzid = jstz.determine().name();
    
      // using moment-timezone
      var tzid = moment.tz.guess();
    

    In both cases, the result can only be thought of as a guess. The guess may be correct in many cases, but not all of them.

    Additionally, these libraries have to be periodically updated to counteract the fact that many older JavaScript implementations are only aware of the current daylight saving time rule for their local time zone. More details on that here.

Ultimately, a better approach is to actually ask your user for their time zone. Provide a setting that they can change. You can use one of the above options to choose a default setting, but don't make it impossible to deviate from that in your app.

There's also the entirely different approach of not relying on the time zone setting of the user's computer at all. Instead, if you can gather latitude and longitude coordinates, you can resolve those to a time zone using one of these methods. This works well on mobile devices.

T-SQL Format integer to 2-digit string

SELECT RIGHT('0' + CAST(sortexport_csv AS VARCHAR), 2)
FROM your_table

How to actually search all files in Visual Studio

One can access the "Find in Files" window via the drop-down menu selection and search all files in the Entire Solution: Edit > Find and Replace > Find in Files

enter image description here

Other, alternative is to open the "Find in Files" window via the "Standard Toolbars" button as highlighted in the below screen-short:

enter image description here

How can I read inputs as numbers?

I encountered a problem of taking integer input while solving a problem on CodeChef, where two integers - separated by space - should be read from one line.

While int(input()) is sufficient for a single integer, I did not find a direct way to input two integers. I tried this:

num = input()
num1 = 0
num2 = 0

for i in range(len(num)):
    if num[i] == ' ':
        break

num1 = int(num[:i])
num2 = int(num[i+1:])

Now I use num1 and num2 as integers. Hope this helps.

What is the difference between a stored procedure and a view?

Main difference is that when you are querying a view then it's definition is pasted into your query. Procedure could also give results of query, but it is compiled and for so faster. Another option are indexed views..

Open links in new window using AngularJS

I have gone through many links but this answer helped me alot:

$scope.redirectPage = function (data) { $window.open(data, "popup", "width=1000,height=700,left=300,top=200"); };

** data will be absolute url which you are hitting.

No String-argument constructor/factory method to deserialize from String value ('')

Use below code snippet This worked for me

ObjectMapper objectMapper = new ObjectMapper();
String jsonString = "{\"symbol\":\"ABCD\}";
objectMapper.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
Trade trade = objectMapper.readValue(jsonString, new TypeReference<Symbol>() {});

Model Class

@JsonIgnoreProperties    public class Symbol {
    @JsonProperty("symbol")
    private String symbol;
}

How can I make the browser wait to display the page until it's fully loaded?

There is certainly a valid use for this. One is to prevent people from clicking on links/causing JavaScript events to occur until all the page elements and JavaScript have loaded.

In IE, you could use page transitions which mean the page doesn't display until it's fully loaded:

<meta http-equiv="Page-Enter" content="blendTrans(Duration=.01)" />
<meta http-equiv="Page-Exit" content="blendTrans(Duration=.01)" />

Notice the short duration. It's just enough to make sure the page doesn't display until it's fully loaded.

In FireFox and other browsers, the solution I've used is to create a DIV that is the size of the page and white, then at the very end of the page put in JavaScript that hides it. Another way would be to use jQuery and hide it as well. Not as painless as the IE solution but both work well.

Write HTML to string

You could use System.Xml.Linq objects. They were totally redesigned from the old System.Xml days which made constructing XML from scratch really annoying.

Other than the doctype I guess, you could easily do something like:

var html = new XElement("html",
    new XElement("head",
        new XElement("title", "My Page")
    ),
    new XElement("body",
        "this is some text"
    )
);

What ports does RabbitMQ use?

Port Access

Firewalls and other security tools may prevent RabbitMQ from binding to a port. When that happens, RabbitMQ will fail to start. Make sure the following ports can be opened:

4369: epmd, a peer discovery service used by RabbitMQ nodes and CLI tools

5672, 5671: used by AMQP 0-9-1 and 1.0 clients without and with TLS

25672: used by Erlang distribution for inter-node and CLI tools communication and is allocated from a dynamic range (limited to a single port by default, computed as AMQP port + 20000). See networking guide for details.

15672: HTTP API clients and rabbitmqadmin (only if the management plugin is enabled)

61613, 61614: STOMP clients without and with TLS (only if the STOMP plugin is enabled)

1883, 8883: (MQTT clients without and with TLS, if the MQTT plugin is enabled

15674: STOMP-over-WebSockets clients (only if the Web STOMP plugin is enabled)

15675: MQTT-over-WebSockets clients (only if the Web MQTT plugin is enabled)

Reference doc: https://www.rabbitmq.com/install-windows-manual.html

Format Date time in AngularJS

I know this is an old item, but thought I'd throw in another option to consider.

As the original string doesn't include the "T" demarker, the default implementation in Angular doesn't recognize it as a date. You can force it using new Date, but that is a bit of a pain on an array. Since you can pipe filters together, you might be able to use a filter to convert your input to a date and then apply the date: filter on the converted date. Create a new custom filter as follows:

app
.filter("asDate", function () {
    return function (input) {
        return new Date(input);
    }
});

Then in your markup, you can pipe the filters together:

{{item.myDateTimeString | asDate | date:'shortDate'}}

Multiline editing in Visual Studio Code

In Visual Studio Code just press Alt and place your cursor to the edit place(where you want to edit) and right click to select.

Windows path in Python

Use the os.path module.

os.path.join( "C:", "meshes", "as" )

Or use raw strings

r"C:\meshes\as"

I would also recommend no spaces in the path or file names. And you could use double backslashes in your strings.

"C:\\meshes\\as.jpg"

Add property to an array of objects

With ES6 you can simply do:

 for(const element of Results) {
      element.Active = "false";
 }

How to make a phone call using intent in Android?

11-25 14:47:01.681: ERROR/AndroidRuntime(302): blah blah...requires android.permission.CALL_PHONE

^ The answer lies in the exception output "requires android.permission.CALL_PHONE" :)

How to create an Array, ArrayList, Stack and Queue in Java?

I am guessing you're confused with the parameterization of the types:

// This works, because there is one class/type definition in the parameterized <> field
ArrayList<String> myArrayList = new ArrayList<String>(); 


// This doesn't work, as you cannot use primitive types here
ArrayList<char> myArrayList = new ArrayList<char>();

What's the difference between ngOnInit and ngAfterViewInit of Angular2?

Content is what is passed as children. View is the template of the current component.

The view is initialized before the content and ngAfterViewInit() is therefore called before ngAfterContentInit().

** ngAfterViewInit() is called when the bindings of the children directives (or components) have been checked for the first time. Hence its perfect for accessing and manipulating DOM with Angular 2 components. As @Günter Zöchbauer mentioned before is correct @ViewChild() hence runs fine inside it.

Example:

@Component({
    selector: 'widget-three',
    template: `<input #input1 type="text">`
})
export class WidgetThree{
    @ViewChild('input1') input1;

    constructor(private renderer:Renderer){}

    ngAfterViewInit(){
        this.renderer.invokeElementMethod(
            this.input1.nativeElement,
            'focus',
            []
        )
    }
}

Make an html number input always display 2 decimal places

Pure html is not able to do what you want. My suggestion would be to write a simple javascript function to do the roudning for you.

Editing legend (text) labels in ggplot

The legend titles can be labeled by specific aesthetic.

This can be achieved using the guides() or labs() functions from ggplot2 (more here and here). It allows you to add guide/legend properties using the aesthetic mapping.

Here's an example using the mtcars data set and labs():

ggplot(mtcars, aes(x=mpg, y=disp, size=hp, col=as.factor(cyl), shape=as.factor(gear))) +
  geom_point() +
  labs(x="miles per gallon", y="displacement", size="horsepower", 
       col="# of cylinders", shape="# of gears")

enter image description here

Answering the OP's question using guides():

# transforming the data from wide to long
require(reshape2)
dfm <- melt(df, id="TY")

# creating a scatterplot
ggplot(data = dfm, aes(x=TY, y=value, color=variable)) + 
  geom_point(size=5) +
  labs(title="Temperatures\n", x="TY [°C]", y="Txxx") +
  scale_color_manual(labels = c("T999", "T888"), values = c("blue", "red")) +
  theme_bw() +
  guides(color=guide_legend("my title"))  # add guide properties by aesthetic

enter image description here

Getting individual colors from a color map in matplotlib

To build on the solutions from Ffisegydd and amaliammr, here's an example where we make CSV representation for a custom colormap:

#! /usr/bin/env python3
import matplotlib
import numpy as np 

vmin = 0.1
vmax = 1000

norm = matplotlib.colors.Normalize(np.log10(vmin), np.log10(vmax))
lognum = norm(np.log10([.5, 2., 10, 40, 150,1000]))

cdict = {
    'red':
    (
        (0., 0, 0),
        (lognum[0], 0, 0),
        (lognum[1], 0, 0),
        (lognum[2], 1, 1),
        (lognum[3], 0.8, 0.8),
        (lognum[4], .7, .7),
    (lognum[5], .7, .7)
    ),
    'green':
    (
        (0., .6, .6),
        (lognum[0], 0.8, 0.8),
        (lognum[1], 1, 1),
        (lognum[2], 1, 1),
        (lognum[3], 0, 0),
        (lognum[4], 0, 0),
    (lognum[5], 0, 0)
    ),
    'blue':
    (
        (0., 0, 0),
        (lognum[0], 0, 0),
        (lognum[1], 0, 0),
        (lognum[2], 0, 0),
        (lognum[3], 0, 0),
        (lognum[4], 0, 0),
    (lognum[5], 1, 1)
    )
}


mycmap = matplotlib.colors.LinearSegmentedColormap('my_colormap', cdict, 256)   
norm = matplotlib.colors.LogNorm(vmin, vmax)
colors = {}
count = 0
step_size = 0.001
for value in np.arange(vmin, vmax+step_size, step_size):
    count += 1
    print("%d/%d %f%%" % (count, vmax*(1./step_size), 100.*count/(vmax*(1./step_size))))
    rgba = mycmap(norm(value), bytes=True)
    color = (rgba[0], rgba[1], rgba[2])
    if color not in colors.values():
        colors[value] = color

print ("value, red, green, blue")
for value in sorted(colors.keys()):
    rgb = colors[value]
    print("%s, %s, %s, %s" % (value, rgb[0], rgb[1], rgb[2]))

How to change proxy settings in Android (especially in Chrome)

Found one solution for WIFI (works for Android 4.3, 4.4):

  1. Connect to WIFI network (e.g. 'Alex')
  2. Settings->WIFI
  3. Long tap on connected network's name (e.g. on 'Alex')
  4. Modify network config-> Show advanced options
  5. Set proxy settings

Vim autocomplete for Python

I found a good choice to be coc.nvim with the python language server.

It takes a bit of effort to set up. I got frustrated with jedi-vim, because it would always freeze vim for a bit when completing. coc.nvim doesn't do it because it's asyncronous, meaning that . It also gives you linting for your code. It supports many other languages and is highly configurable.

The python language server uses jedi so you get the same completion as you would get from jedi.

Dictionary text file

What about /usr/share/dict/words on any Unix system? How many words are we talking about? Like OED-Unabridged?

How to link to a named anchor in Multimarkdown?

Here is my solution (derived from SaraubhM's answer)

**Jump To**: [Hotkeys & Markers](#hotkeys-markers) / [Radii](#radii) / [Route Wizard 2.0](#route-wizard-2-0)

Which gives you:

Jump To: Hotkeys & Markers / Radii / Route Wizard 2.0

Note the changes from and . to - and also the loss of the & in the links.

Global variables in c#.net

You can create a base class in your application that inherits from System.Web.UI.Page. Let all your pages inherit from the newly created base class. Add a property or a variable to your base class with propected access modifier, so that it will be accessed from all your pages in the application.

How do I check if a string is a number (float)?

This answer provides step by step guide having function with examples to find the string is:

  • Positive integer
  • Positive/negative - integer/float
  • How to discard "NaN" (not a number) strings while checking for number?

Check if string is positive integer

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

Sample Results:

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

Check for string as positive/negative - integer/float

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

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

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

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

Sample Run:

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

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

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

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

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

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

>>> is_number('NaN')
True

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

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

>>> math.isnan(nan_num)
True

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

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

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

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

Sample Run:

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

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

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

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

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

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

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

Difference between numeric, float and decimal in SQL Server

Float is Approximate-number data type, which means that not all values in the data type range can be represented exactly.

Decimal/Numeric is Fixed-Precision data type, which means that all the values in the data type range can be represented exactly with precision and scale. You can use decimal for money saving.

Converting from Decimal or Numeric to float can cause some loss of precision. For the Decimal or Numeric data types, SQL Server considers each specific combination of precision and scale as a different data type. DECIMAL(2,2) and DECIMAL(2,4) are different data types. This means that 11.22 and 11.2222 are different types though this is not the case for float. For FLOAT(6) 11.22 and 11.2222 are same data types.

You can also use money data type for saving money. This is native data type with 4 digit precision for money. Most experts prefers this data type for saving money.

Reference 1 2 3

How to solve error "Missing `secret_key_base` for 'production' environment" (Rails 4.1)

What I did : On my production server, I create a config file (confthin.yml) for Thin (I'm using it) and add the following information :

environment: production
user: www-data
group: www-data
SECRET_KEY_BASE: mysecretkeyproduction

I then launch the app with

thin start -C /whereeveristhefieonprod/configthin.yml

Work like a charm and then no need to have the secret key on version control

Hope it could help, but I'm sure the same thing could be done with Unicorn and others.

How to split page into 4 equal parts?

Some good answers here but just adding an approach that won't be affected by borders and padding:

<style type="text/css">
html, body{width: 100%; height: 100%; padding: 0; margin: 0}
div{position: absolute; padding: 1em; border: 1px solid #000}
#nw{background: #f09; top: 0; left: 0; right: 50%; bottom: 50%}
#ne{background: #f90; top: 0; left: 50%; right: 0; bottom: 50%}
#sw{background: #009; top: 50%; left: 0; right: 50%; bottom: 0}
#se{background: #090; top: 50%; left: 50%; right: 0; bottom: 0}
</style>

<div id="nw">test</div>
<div id="ne">test</div>
<div id="sw">test</div>
<div id="se">test</div>

sass :first-child not working

First of all, there are still browsers out there that don't support those pseudo-elements (ie. :first-child, :last-child), so you have to 'deal' with this issue.

There is a good example how to make that work without using pseudo-elements:

http://www.darowski.com/tracesofinspiration/2010/01/11/this-newbies-first-impressions-of-haml-and-sass/

       -- see the divider pipe example.

I hope that was useful.

Pointer-to-pointer dynamic two-dimensional array

What you describe for the second method only gives you a 1D array:

int *board = new int[10];

This just allocates an array with 10 elements. Perhaps you meant something like this:

int **board = new int*[4];
for (int i = 0; i < 4; i++) {
  board[i] = new int[10];
}

In this case, we allocate 4 int*s and then make each of those point to a dynamically allocated array of 10 ints.

So now we're comparing that with int* board[4];. The major difference is that when you use an array like this, the number of "rows" must be known at compile-time. That's because arrays must have compile-time fixed sizes. You may also have a problem if you want to perhaps return this array of int*s, as the array will be destroyed at the end of its scope.

The method where both the rows and columns are dynamically allocated does require more complicated measures to avoid memory leaks. You must deallocate the memory like so:

for (int i = 0; i < 4; i++) {
  delete[] board[i];
}
delete[] board;

I must recommend using a standard container instead. You might like to use a std::array<int, std::array<int, 10> 4> or perhaps a std::vector<std::vector<int>> which you initialise to the appropriate size.

Server Error in '/' Application. ASP.NET

The key information in this error is this line:

This error can be caused by a virtual directory not being configured as an application in IIS.

In IIS, you can have several applications, but they must be configured as an application. Generally, when you create a web project it maps directly to an IIS application.

Check with your hosting service on how to create an IIS application for your web app.

Edit - added If this is on your server, you can set this up yourself following the instructions in @Frazell Thomas's answer. He beat me to finding that link. To save yourself some reading, you should be able to focus in on the Creating Virtual Directories and Local Web Sites section.

Filtering DataGridView without changing datasource

A simpler way is to transverse the data, and hide the lines with the Visible property.

// Prevent exception when hiding rows out of view
CurrencyManager currencyManager = (CurrencyManager)BindingContext[dataGridView3.DataSource];
currencyManager.SuspendBinding();

// Show all lines
for (int u = 0; u < dataGridView3.RowCount; u++)
{
    dataGridView3.Rows[u].Visible = true;
    x++;
}

// Hide the ones that you want with the filter you want.
for (int u = 0; u < dataGridView3.RowCount; u++)
{
    if (dataGridView3.Rows[u].Cells[4].Value == "The filter string")
    {
        dataGridView3.Rows[u].Visible = true;
    }
    else
    {
        dataGridView3.Rows[u].Visible = false;
    }
}

// Resume data grid view binding
currencyManager.ResumeBinding();

Just an idea... it works for me.

Resizing UITableView to fit content

This works for me using Auto Layout, with a table view with only one section.

func getTableViewContentHeight(tableView: UITableView) -> CGFloat {
        tableView.bounds = CGRect(x: 0, y: 0, width: 300, height: 40)
        let rows = tableView.numberOfRows(inSection: 0)
        var height = CGFloat(0)
        for n in 0...rows - 1 {
            height = height + tableView.rectForRow(at: IndexPath(row: n, section: 0)).height
        }
        return height
    }

I call this function when setting up Auto Layout (The sample here uses SnapKit, but you get the idea):

    let height = getTableViewContentHeight(tableView: myTableView)
    myTableView.snp.makeConstraints {
        ...
        ...
        $0.height.equalTo(height)
    }

I want the UITableView only to be as tall as the combined height of the cells; I loop through the cells and accumulate the total height of the cells. Since the size of the table view is CGRect.zero at this point, I need to set the bounds to be able to respect the Auto Layout rules defined by the cell. I set the size to an arbitrary value that should be large enough. The actual size will be calculated later by the Auto Layout system.

index.php not loading by default

This might be helpful to somebody. here is the snippet from httpd.conf (Apache version 2.2 windows)

# DirectoryIndex: sets the file that Apache will serve if a directory
# is requested.
#
<IfModule dir_module>
    DirectoryIndex index.html
    DirectoryIndex index.php
</IfModule>

now this will look for index.html file if not found it will look for index.php.

How to change the docker image installation directory?

With recent versions of Docker, you would set the value of the data-root parameter to your custom path, in /etc/docker/daemon.json (according to https://docs.docker.com/engine/reference/commandline/dockerd/#daemon-configuration-file).

With older versions, you can change Docker's storage base directory (where container and images go) using the -goption when starting the Docker daemon. (check docker --help). You can have this setting applied automatically when Docker starts by adding it to /etc/default/docker

CSS I want a div to be on top of everything

I gonna assumed you making a popup with code from WW3 school, correct? check it css. the .modal one, there're already word z-index there. just change from 1 to 100.

.modal {
    display: none; /* Hidden by default */
    position: fixed; /* Stay in place */
    z-index: 1; /* Sit on top */
    padding-top: 100px; /* Location of the box */
    left: 0;
    top: 0;
    width: 100%; /* Full width */
    height: 100%; /* Full height */
    overflow: auto; /* Enable scroll if needed */
    background-color: rgb(0,0,0); /* Fallback color */
    background-color: rgba(0,0,0,0.4); /* Black w/ opacity */
}

How to execute mongo commands through shell scripts?

This works for me under Linux:

mongo < script.js

How to handle the click event in Listview in android?

    //get main activity
    final Activity main_activity=getActivity();

    //list view click listener
    final ListView listView = (ListView) inflatedView.findViewById(R.id.listView_id);
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            String stringText;

            //in normal case
            stringText= ((TextView)view).getText().toString();                

            //in case if listview has separate item layout
            TextView textview=(TextView)view.findViewById(R.id.textview_id_of_listview_Item);
            stringText=textview.getText().toString();                

            //show selected
            Toast.makeText(main_activity, stringText, Toast.LENGTH_LONG).show();
        }
    });

    //populate listview

linq where list contains any in list

Or like this

class Movie
{
  public string FilmName { get; set; }
  public string Genre { get; set; }
}

...

var listofGenres = new List<string> { "action", "comedy" };

var Movies = new List<Movie> {new Movie {Genre="action", FilmName="Film1"},
                new Movie {Genre="comedy", FilmName="Film2"},
                new Movie {Genre="comedy", FilmName="Film3"},
                new Movie {Genre="tragedy", FilmName="Film4"}};

var movies = Movies.Join(listofGenres, x => x.Genre, y => y, (x, y) => x).ToList();

Simulating Slow Internet Connection

On Linux machines u can use wondershaper

apt-get install wondershaper

$ sudo wondershaper {interface} {down} {up}

the {down} and {up} are bandwidth in kpbs

So for example if you want to limit the bandwidth of interface eth1 to 256kbps uplink and 128kbps downlink,

$ sudo wondershaper eth1 256 128

To clear the limit,

$ sudo wondershaper clear eth1 

SQL Error: ORA-00933: SQL command not properly ended

Your query should look like

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value

You can check the below question for help

How to show Bootstrap table with sort icon

BOOTSTRAP 4

you can use a combination of

  • fa-chevron-down, fa-chevron-up

  • fa-sort-down, fa-sort-up

<th class="text-center">
    <div class="btn-group" role="group">
        <button type="button" class="btn btn-xs btn-link py-0 pl-0 pr-1">
             Some Text OR icon
        </button>
        <div class="btn-group-vertical">
            <a href="?sort=asc" class="btn btn-xs btn-link p-0">
                <i class="fas fa-sort-up"></i>
            </a>
            <a href="?sort=desc" class="btn btn-xs btn-link p-0">
                <i class="fas fa-sort-down"></i>
            </a>
        </div>
    </div>
</th>

Why is __init__() always called after __new__()?

To quote the documentation:

Typical implementations create a new instance of the class by invoking the superclass's __new__() method using "super(currentclass, cls).__new__(cls[, ...])"with appropriate arguments and then modifying the newly-created instance as necessary before returning it.

...

If __new__() does not return an instance of cls, then the new instance's __init__() method will not be invoked.

__new__() is intended mainly to allow subclasses of immutable types (like int, str, or tuple) to customize instance creation.

Trees in Twitter Bootstrap

If someone wants vertical version of the treeview from Harsh's answer, you can save some time:

http://jsfiddle.net/Fh47n/

.tree li {
    margin: 0px 0;

    list-style-type: none;
    position: relative;
    padding: 20px 5px 0px 5px;
}

.tree li::before{
    content: '';
    position: absolute; 
    top: 0;
    width: 1px; 
    height: 100%;
    right: auto; 
    left: -20px;
    border-left: 1px solid #ccc;
    bottom: 50px;
}
.tree li::after{
    content: '';
    position: absolute; 
    top: 30px; 
    width: 25px; 
    height: 20px;
    right: auto; 
    left: -20px;
    border-top: 1px solid #ccc;
}
.tree li a{
    display: inline-block;
    border: 1px solid #ccc;
    padding: 5px 10px;
    text-decoration: none;
    color: #666;
    font-family: arial, verdana, tahoma;
    font-size: 11px;
    border-radius: 5px;
    -webkit-border-radius: 5px;
    -moz-border-radius: 5px;
}

/*Remove connectors before root*/
.tree > ul > li::before, .tree > ul > li::after{
    border: 0;
}
/*Remove connectors after last child*/
.tree li:last-child::before{ 
      height: 30px;
}

/*Time for some hover effects*/
/*We will apply the hover effect the the lineage of the element also*/
.tree li a:hover, .tree li a:hover+ul li a {
    background: #c8e4f8; color: #000; border: 1px solid #94a0b4;
}
/*Connector styles on hover*/
.tree li a:hover+ul li::after, 
.tree li a:hover+ul li::before, 
.tree li a:hover+ul::before, 
.tree li a:hover+ul ul::before{
    border-color:  #94a0b4;
}

JavaScript set object key by variable

You need to make the object first, then use [] to set it.

var key = "happyCount";
var obj = {};
obj[key] = someValueArray;
myArray.push(obj);

UPDATE 2018:

If you're able to use ES6 and Babel, you can use this new feature:

{
    [yourKeyVariable]: someValueArray,
}  

How do I create a new branch?

In the Repository Browser of TortoiseSVN, find the branch that you want to create the new branch from. Right-click, Copy To.... and enter the new branch path. Now you can "switch" your local WC to that branch.

XAMPP installation on Win 8.1 with UAC Warning

I don't know if you are still having this problem, but I had the same problem and had a different fix than what was listed in the other answer. I did install XAMPP under C:\xampp\, and my user is an admin, but there was also something else.

I had to manually go give my user full access to the C:\Users\XAMPP\ directory. By default (at least on my machine) Windows did not give my admin user rights to this new user's directory, but this is where XAMPP stores all of it's config files. Once I gave myself full access to this, everything worked perfectly.

Hope this helps!

UPDATE!

In retrospect, I think that I must have accidentally typed in "C:\Users\XAMPP\" as the install folder during the installation process. So I think the most important thing is to make sure that the user you are actually signed into Windows as when you start XAMPP has full access to the folder that it was actually installed to.

Adding header for HttpURLConnection

If you are using Java 8, use the code below.

URLConnection connection = url.openConnection();
HttpURLConnection httpConn = (HttpURLConnection) connection;

String basicAuth = Base64.getEncoder().encodeToString((username+":"+password).getBytes(StandardCharsets.UTF_8));
httpConn.setRequestProperty ("Authorization", "Basic "+basicAuth);

sed command with -i option failing on Mac, but works on Linux

Your Mac does indeed run a BASH shell, but this is more a question of which implementation of sed you are dealing with. On a Mac sed comes from BSD and is subtly different from the sed you might find on a typical Linux box. I suggest you man sed.

How to open Atom editor from command line in OS X?

The symlink solution for this stopped working for me in zsh today. I ended up creating an alias in my .zshrc file instead:

alias atom='sh /Applications/Atom.app/Contents/Resources/app/atom.sh'

How to truncate milliseconds off of a .NET DateTime

In my case, I was aiming to save TimeSpan from datetimePicker tool without saving the seconds and the milliseconds, and here is the solution.

First convert the datetimePicker.value to your desired format, which mine is "HH:mm" then convert it back to TimeSpan.

var datetime = datetimepicker1.Value.ToString("HH:mm");
TimeSpan timeSpan = Convert.ToDateTime(datetime).TimeOfDay;

Loading inline content using FancyBox

Just something I found for Wordpress users,

As obvious as it sounds, If your div is returning some AJAX content based on say a header that would commonly link out to a new post page, some tutorials will say to return false since you're returning the post data on the same page and the return would prevent the page from moving. However if you return false, you also prevent Fancybox2 from doing it's thing as well. I spent hours trying to figure that stupid simple thing out.

So for these kind of links, just make sure that the href property is the hashed (#) div you wish to select, and in your javascript, make sure that you do not return false since you no longer will need to.

Simple I know ^_^

How to document Python code using Doxygen

This is documented on the doxygen website, but to summarize here:

You can use doxygen to document your Python code. You can either use the Python documentation string syntax:

"""@package docstring
Documentation for this module.

More details.
"""

def func():
    """Documentation for a function.

    More details.
    """
    pass

In which case the comments will be extracted by doxygen, but you won't be able to use any of the special doxygen commands.

Or you can (similar to C-style languages under doxygen) double up the comment marker (#) on the first line before the member:

## @package pyexample
#  Documentation for this module.
#
#  More details.

## Documentation for a function.
#
#  More details.
def func():
    pass

In that case, you can use the special doxygen commands. There's no particular Python output mode, but you can apparently improve the results by setting OPTMIZE_OUTPUT_JAVA to YES.

Honestly, I'm a little surprised at the difference - it seems like once doxygen can detect the comments in ## blocks or """ blocks, most of the work would be done and you'd be able to use the special commands in either case. Maybe they expect people using """ to adhere to more Pythonic documentation practices and that would interfere with the special doxygen commands?

Set variable with multiple values and use IN

You need a table variable:

declare @values table
(
    Value varchar(1000)
)

insert into @values values ('A')
insert into @values values ('B')
insert into @values values ('C')

select blah
from foo
where myField in (select value from @values)

How can I make a horizontal ListView in Android?

I used Pauls (see his answer) Implementation of HorizontalListview and it works, thank you so much for sharing!

I slightly changed his HorizontalListView-Class (btw. Paul there is a typo in your classname, your classname is "HorizontialListView" instead of "HorizontalListView", the "i" is too much) to update child-views when selected.

UPDATE: My code that I posted here was wrong I suppose, as I ran into trouble with selection (i think it has to do with view recycling), I have to go back to the drawing board...

UPDATE 2: Ok Problem solved, I simply commented "removeNonVisibleItems(dx);" in "onLayout(..)", I guess this will hurt performance, but since I am using only very small Lists this is no Problem for me.

I basically used this tutorial here on developerlife and just replaced ListView with Pauls HorizontalListView, and made the changes to allow for "permanent" selection (a child that is clicked on changes its appearance, and when its clicked on again it changes it back).

I am a beginner, so probably many ugly things in the code, let me know if you need more details.

Java - Check Not Null/Empty else assign default value

Use org.apache.commons.lang3.StringUtils

String emptyString = new String();    
result = StringUtils.defaultIfEmpty(emptyString, "default");
System.out.println(result);

String nullString = null;
result = StringUtils.defaultIfEmpty(nullString, "default");
System.out.println(result);

Both of the above options will print:

default

default

Rails Model find where not equal

You should always include the table name in the SQL query when dealing with associations.

Indeed if another table has the user_id column and you join both tables, you will have an ambiguous column name in the SQL query (i.e. troubles).

So, in your example:

GroupUser.where("groups_users.user_id != ?", me)

Or a bit more verbose:

GroupUser.where("#{table_name}.user_id IS NOT ?", me)

Note that if you are using a hash, you don't need to worry about that because Rails takes care of it for you:

GroupUser.where(user: me)

In Rails 4, as said by @dr4k3, the query method not has been added:

GroupUser.where.not(user: me)

Print empty line?

This is are other ways of printing empty lines in python

# using \n after the string creates an empty line after this string is passed to the the terminal.
print("We need to put about", average_passengers_per_car, "in each car. \n") 
print("\n") #prints 2 empty lines 
print() #prints 1 empty line 

How to iterate a loop with index and element in Swift

Using .enumerate() works, but it does not provide the true index of the element; it only provides an Int beginning with 0 and incrementing by 1 for each successive element. This is usually irrelevant, but there is the potential for unexpected behavior when used with the ArraySlice type. Take the following code:

let a = ["a", "b", "c", "d", "e"]
a.indices //=> 0..<5

let aSlice = a[1..<4] //=> ArraySlice with ["b", "c", "d"]
aSlice.indices //=> 1..<4

var test = [Int: String]()
for (index, element) in aSlice.enumerate() {
    test[index] = element
}
test //=> [0: "b", 1: "c", 2: "d"] // indices presented as 0..<3, but they are actually 1..<4
test[0] == aSlice[0] // ERROR: out of bounds

It's a somewhat contrived example, and it's not a common issue in practice but still I think it's worth knowing this can happen.

Detect Route Change with react-router

You can make use of history.listen() function when trying to detect the route change. Considering you are using react-router v4, wrap your component with withRouter HOC to get access to the history prop.

history.listen() returns an unlisten function. You'd use this to unregister from listening.

You can configure your routes like

index.js

ReactDOM.render(
      <BrowserRouter>
            <AppContainer>
                   <Route exact path="/" Component={...} />
                   <Route exact path="/Home" Component={...} />
           </AppContainer>
        </BrowserRouter>,
  document.getElementById('root')
);

and then in AppContainer.js

class App extends Component {
  
  componentWillMount() {
    this.unlisten = this.props.history.listen((location, action) => {
      console.log("on route change");
    });
  }
  componentWillUnmount() {
      this.unlisten();
  }
  render() {
     return (
         <div>{this.props.children}</div>
      );
  }
}
export default withRouter(App);

From the history docs:

You can listen for changes to the current location using history.listen:

history.listen((location, action) => {
      console.log(`The current URL is ${location.pathname}${location.search}${location.hash}`)
  console.log(`The last navigation action was ${action}`)
})

The location object implements a subset of the window.location interface, including:

**location.pathname** - The path of the URL
**location.search** - The URL query string
**location.hash** - The URL hash fragment

Locations may also have the following properties:

location.state - Some extra state for this location that does not reside in the URL (supported in createBrowserHistory and createMemoryHistory)

location.key - A unique string representing this location (supported in createBrowserHistory and createMemoryHistory)

The action is one of PUSH, REPLACE, or POP depending on how the user got to the current URL.

When you are using react-router v3 you can make use of history.listen() from history package as mentioned above or you can also make use browserHistory.listen()

You can configure and use your routes like

import {browserHistory} from 'react-router';

class App extends React.Component {

    componentDidMount() {
          this.unlisten = browserHistory.listen( location =>  {
                console.log('route changes');
                
           });
      
    }
    componentWillUnmount() {
        this.unlisten();
     
    }
    render() {
        return (
               <Route path="/" onChange={yourHandler} component={AppContainer}>
                   <IndexRoute component={StaticContainer}  />
                   <Route path="/a" component={ContainerA}  />
                   <Route path="/b" component={ContainerB}  />
            </Route>
        )
    }
} 

How to replace all occurrences of a string in Javascript?

Use a regular expression:

str.replace(/abc/g, '');

UIImage resize (Scale proportion)

This fixes the math to scale to the max size in both width and height rather than just one depending on the width and height of the original.

- (UIImage *) scaleProportionalToSize: (CGSize)size
{
    float widthRatio = size.width/self.size.width;
    float heightRatio = size.height/self.size.height;

    if(widthRatio > heightRatio)
    {
        size=CGSizeMake(self.size.width*heightRatio,self.size.height*heightRatio);
    } else {
        size=CGSizeMake(self.size.width*widthRatio,self.size.height*widthRatio);
    }

    return [self scaleToSize:size];
}

Is it possible to ping a server from Javascript?

Ping is ICMP, but if there is any open TCP port on the remote server it could be achieved like this:

function ping(host, port, pong) {

  var started = new Date().getTime();

  var http = new XMLHttpRequest();

  http.open("GET", "http://" + host + ":" + port, /*async*/true);
  http.onreadystatechange = function() {
    if (http.readyState == 4) {
      var ended = new Date().getTime();

      var milliseconds = ended - started;

      if (pong != null) {
        pong(milliseconds);
      }
    }
  };
  try {
    http.send(null);
  } catch(exception) {
    // this is expected
  }

}

Extract column values of Dataframe as List in Apache Spark

In Scala and Spark 2+, try this (assuming your column name is "s"): df.select('s).as[String].collect

How to add a ScrollBar to a Stackpanel

If you mean, you want to scroll through multiple items in your stackpanel, try putting a grid around it. By definition, a stackpanel has infinite length.

So try something like this:

   <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
        <StackPanel Width="311">
              <TextBlock Text="{Binding A}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}" FontStretch="Condensed" FontSize="28" />
              <TextBlock Text="{Binding B}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
        </StackPanel>
    </Grid>

You could even make this work with a ScrollViewer

Cannot read configuration file due to insufficient permissions

Had this issue with a Virtual Application. All the permissions were set. IIS_IUSRS, AppPoolIdentity and then gave full access to Everyone. Nothing worked. Restarted apppool, site and IIS but No go.

Deleted the virtual application and added it again from scratch and it started working.

Wish I knew what solved it.

No connection could be made because the target machine actively refused it (PHP / WAMP)

  1. Go to C:\wamp\bin\mysql\mysql[your-version]\data
  2. Copy and save "ib_logfile0" and "ib_logfile1" anywhere else.
  3. delete "ib_logfile0" and ib_logfile1

Did the trick for me. hope it works for you too.

Its working fine. But we will have to stop apache and mysql, We need to quit xampp and then delete file. when deleted successfully. now start xampp it will work properly..

Setting Custom ActionBar Title from Fragment

The downside to your approach of casting like so

((MainFragmentActivity) getActivity()).getSupportActionBar().setTitle(
        catTitle);

is that your fragment is no longer reusable outside of MainActivityFragment. If you don't plan to use it outside of that activity, then there's no problem. A better approach would be conditionally set the title depending on the activity. So inside your fragment, you would write:

if (getActivity() instanceof ActionBarActivity) {
    ((ActionBarActivity) getActivity()).getSupportActionBar().setTitle("Some Title");
}

What is the best way to repeatedly execute a function every x seconds?

If you want a non-blocking way to execute your function periodically, instead of a blocking infinite loop I'd use a threaded timer. This way your code can keep running and perform other tasks and still have your function called every n seconds. I use this technique a lot for printing progress info on long, CPU/Disk/Network intensive tasks.

Here's the code I've posted in a similar question, with start() and stop() control:

from threading import Timer

class RepeatedTimer(object):
    def __init__(self, interval, function, *args, **kwargs):
        self._timer     = None
        self.interval   = interval
        self.function   = function
        self.args       = args
        self.kwargs     = kwargs
        self.is_running = False
        self.start()

    def _run(self):
        self.is_running = False
        self.start()
        self.function(*self.args, **self.kwargs)

    def start(self):
        if not self.is_running:
            self._timer = Timer(self.interval, self._run)
            self._timer.start()
            self.is_running = True

    def stop(self):
        self._timer.cancel()
        self.is_running = False

Usage:

from time import sleep

def hello(name):
    print "Hello %s!" % name

print "starting..."
rt = RepeatedTimer(1, hello, "World") # it auto-starts, no need of rt.start()
try:
    sleep(5) # your long-running job goes here...
finally:
    rt.stop() # better in a try/finally block to make sure the program ends!

Features:

  • Standard library only, no external dependencies
  • start() and stop() are safe to call multiple times even if the timer has already started/stopped
  • function to be called can have positional and named arguments
  • You can change interval anytime, it will be effective after next run. Same for args, kwargs and even function!

How do I sort a list of datetime or date objects?

You're getting None because list.sort() it operates in-place, meaning that it doesn't return anything, but modifies the list itself. You only need to call a.sort() without assigning it to a again.

There is a built in function sorted(), which returns a sorted version of the list - a = sorted(a) will do what you want as well.

An efficient compression algorithm for short text strings

Any algorithm/library that supports a preset dictionary, e.g. zlib.

This way you can prime the compressor with the same kind of text that is likely to appear in the input. If the files are similar in some way (e.g. all URLs, all C programs, all StackOverflow posts, all ASCII-art drawings) then certain substrings will appear in most or all of the input files.

Every compression algorithm will save space if the same substring is repeated multiple times in one input file (e.g. "the" in English text or "int" in C code.)

But in the case of URLs certain strings (e.g. "http://www.", ".com", ".html", ".aspx" will typically appear once in each input file. So you need to share them between files somehow rather than having one compressed occurrence per file. Placing them in a preset dictionary will achieve this.

How do I load the contents of a text file into a javascript variable?

here is how I did it in jquery:

jQuery.get('http://localhost/foo.txt', function(data) {
    alert(data);
});

Python basics printing 1 to 100

consider the following:

def gukan(count):
    while count < 100:
      print(count)
      count=count+3;
gukan(0) #prints ..., 93, 96, 99


def gukan(count):
    while count < 100:
      print(count)
      count=count+9;
gukan(0) # prints ..., 81, 90, 99

you should use count < 100 because count will never reach the exact number 100 if you use 3 or 9 as the increment, thus creating an infinite loop.

Good luck!~ :)

Retrieve the maximum length of a VARCHAR column in SQL Server

For Oracle, it is also LENGTH instead of LEN

SELECT MAX(LENGTH(Desc)) FROM table_name

Also, DESC is a reserved word. Although many reserved words will still work for column names in many circumstances it is bad practice to do so, and can cause issues in some circumstances. They are reserved for a reason.

If the word Desc was just being used as an example, it should be noted that not everyone will realize that, but many will realize that it is a reserved word for Descending. Personally, I started off by using this, and then trying to figure out where the column name went because all I had were reserved words. It didn't take long to figure it out, but keep that in mind when deciding on what to substitute for your actual column name.

How to convert a Drawable to a Bitmap?

Here is better resolution

public static Bitmap drawableToBitmap (Drawable drawable) {
    if (drawable instanceof BitmapDrawable) {
        return ((BitmapDrawable)drawable).getBitmap();
    }

    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap); 
    drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
    drawable.draw(canvas);

    return bitmap;
}

public static InputStream bitmapToInputStream(Bitmap bitmap) {
    int size = bitmap.getHeight() * bitmap.getRowBytes();
    ByteBuffer buffer = ByteBuffer.allocate(size);
    bitmap.copyPixelsToBuffer(buffer);
    return new ByteArrayInputStream(buffer.array());
}

Code from How to read drawable bits as InputStream

How to edit an Android app?

You would need to decompile the apk as Davis suggested, can use tools such as apkTool , then if you need to change the source code you would need other tools to do that.

You would then need to put the apk back together and sign it, if you don't have the original key used to sign the apk this means the new apk will have a different signature.

If the developer employed any obfuscation or other techniques to protect the app then it gets more complicated.

In short its a pretty complex and technical procedure, so if the developer is really just out of reach, its better to wait until he is in reach. And ask for the source code next time.

Why are my CSS3 media queries not working on mobile devices?

i used bootstrap in a press site but it does not worked on IE8, i used css3-mediaqueries.js javascript but still not working. if you want your media query to work with this javascript file add screen to your media query line in css

here is an example :

<meta name="viewport" content="width=device-width" />


<style>
     @media screen and (max-width:900px) {}
     @media screen and (min-width:900px) and (max-width:1200px) {}
     @media screen and (min-width:1200px) {}
</style>

<link rel="stylesheet" type="text/css" href="bootstrap.min.css">
<script type="text/javascript" src="css3-mediaqueries.js"></script>

css Link line as simple as above line.

Setting up an MS-Access DB for multi-user access

I have found the SMB2 protocol introduced in Vista to lock the access databases. It can be disabled by the following regedit:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters] "Smb2"=dword:00000000

refresh both the External data source and pivot tables together within a time schedule

Under the connection properties, uncheck "Enable background refresh". This will make the connection refresh when told to, not in the background as other processes happen.

With background refresh disabled, your VBA procedure will wait for your external data to refresh before moving to the next line of code.

Then you just modify the following code:

ActiveWorkbook.Connections("CONNECTION_NAME").Refresh
Sheets("SHEET_NAME").PivotTables("PIVOT_TABLE_NAME").PivotCache.Refresh

You can also turn off background refresh in VBA:

ActiveWorkbook.Connections("CONNECTION_NAME").ODBCConnection.BackgroundQuery = False

Creating an index on a table variable

It should be understood that from a performance standpoint there are no differences between @temp tables and #temp tables that favor variables. They reside in the same place (tempdb) and are implemented the same way. All the differences appear in additional features. See this amazingly complete writeup: https://dba.stackexchange.com/questions/16385/whats-the-difference-between-a-temp-table-and-table-variable-in-sql-server/16386#16386

Although there are cases where a temp table can't be used such as in table or scalar functions, for most other cases prior to v2016 (where even filtered indexes can be added to a table variable) you can simply use a #temp table.

The drawback to using named indexes (or constraints) in tempdb is that the names can then clash. Not just theoretically with other procedures but often quite easily with other instances of the procedure itself which would try to put the same index on its copy of the #temp table.

To avoid name clashes, something like this usually works:

declare @cmd varchar(500)='CREATE NONCLUSTERED INDEX [ix_temp'+cast(newid() as varchar(40))+'] ON #temp (NonUniqueIndexNeeded);';
exec (@cmd);

This insures the name is always unique even between simultaneous executions of the same procedure.

How to delete a file from SD card?

Sorry: There is a mistake in my code before because of the site validation.

String myFile = "/Name Folder/File.jpg";  

String myPath = Environment.getExternalStorageDirectory()+myFile;  

File f = new File(myPath);
Boolean deleted = f.delete();

I think is clear... First you must to know your file location. Second,,, Environment.getExternalStorageDirectory() is a method who gets your app directory. Lastly the class File who handle your file...

How to map an array of objects in React

you must put object in your JSX, It`s easy way to do this just see my simple code here:

const link = [
  {
   name: "Cold Drink",
   link: "/coldDrink"
  },
  {
   name: "Hot Drink",
   link: "/HotDrink"
  },

{ name: "chease Cake", link: "/CheaseCake" } ]; and you must map this array in your code with simple object see this code :

const links = (this.props.link);
{links.map((item, i) => (
 <li key={i}>
   <Link to={item.link}>{item.name}</Link>
 </li>
 ))}

I hope this answer will be helpful for you ...:)

How to receive serial data using android bluetooth

try this code :

Activity:

package Android.Arduino.Bluetooth;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.TextView;
import android.widget.EditText;  
import android.widget.Button;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;

public class MainActivity extends Activity
{
TextView myLabel;
EditText myTextbox;
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;
OutputStream mmOutputStream;
InputStream mmInputStream;
Thread workerThread;
byte[] readBuffer;
int readBufferPosition;
int counter;
volatile boolean stopWorker;

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button openButton = (Button)findViewById(R.id.open);
    Button sendButton = (Button)findViewById(R.id.send);
    Button closeButton = (Button)findViewById(R.id.close);
    myLabel = (TextView)findViewById(R.id.label);
    myTextbox = (EditText)findViewById(R.id.entry);

    //Open Button
    openButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                findBT();
                openBT();
            }
            catch (IOException ex) { }
        }
    });

    //Send Button
    sendButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                sendData();
            }
            catch (IOException ex) { }
        }
    });

    //Close button
    closeButton.setOnClickListener(new View.OnClickListener()
    {
        public void onClick(View v)
        {
            try 
            {
                closeBT();
            }
            catch (IOException ex) { }
        }
    });
}

void findBT()
{
    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if(mBluetoothAdapter == null)
    {
        myLabel.setText("No bluetooth adapter available");
    }

    if(!mBluetoothAdapter.isEnabled())
    {
        Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBluetooth, 0);
    }

    Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
    if(pairedDevices.size() > 0)
    {
        for(BluetoothDevice device : pairedDevices)
        {
            if(device.getName().equals("MattsBlueTooth")) 
            {
                mmDevice = device;
                break;
            }
        }
    }
    myLabel.setText("Bluetooth Device Found");
}

void openBT() throws IOException
{
    UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //Standard SerialPortService ID
    mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);        
    mmSocket.connect();
    mmOutputStream = mmSocket.getOutputStream();
    mmInputStream = mmSocket.getInputStream();

    beginListenForData();

    myLabel.setText("Bluetooth Opened");
}

void beginListenForData()
{
    final Handler handler = new Handler(); 
    final byte delimiter = 10; //This is the ASCII code for a newline character

    stopWorker = false;
    readBufferPosition = 0;
    readBuffer = new byte[1024];
    workerThread = new Thread(new Runnable()
    {
        public void run()
        {                
           while(!Thread.currentThread().isInterrupted() && !stopWorker)
           {
                try 
                {
                    int bytesAvailable = mmInputStream.available();                        
                    if(bytesAvailable > 0)
                    {
                        byte[] packetBytes = new byte[bytesAvailable];
                        mmInputStream.read(packetBytes);
                        for(int i=0;i<bytesAvailable;i++)
                        {
                            byte b = packetBytes[i];
                            if(b == delimiter)
                            {
     byte[] encodedBytes = new byte[readBufferPosition];
     System.arraycopy(readBuffer, 0, encodedBytes, 0, encodedBytes.length);
     final String data = new String(encodedBytes, "US-ASCII");
     readBufferPosition = 0;

                                handler.post(new Runnable()
                                {
                                    public void run()
                                    {
                                        myLabel.setText(data);
                                    }
                                });
                            }
                            else
                            {
                                readBuffer[readBufferPosition++] = b;
                            }
                        }
                    }
                } 
                catch (IOException ex) 
                {
                    stopWorker = true;
                }
           }
        }
    });

    workerThread.start();
}

void sendData() throws IOException
{
    String msg = myTextbox.getText().toString();
    msg += "\n";
    mmOutputStream.write(msg.getBytes());
    myLabel.setText("Data Sent");
}

void closeBT() throws IOException
{
    stopWorker = true;
    mmOutputStream.close();
    mmInputStream.close();
    mmSocket.close();
    myLabel.setText("Bluetooth Closed");
}
}

AND Here the layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:ignore="TextFields,HardcodedText" >

<TextView
    android:id="@+id/label"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Type here:" />

<EditText
    android:id="@+id/entry"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/label"
    android:background="@android:drawable/editbox_background" />

<Button
    android:id="@+id/open"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@id/entry"
    android:layout_marginLeft="10dip"
    android:text="Open" />

<Button
    android:id="@+id/send"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@id/open"
    android:layout_toLeftOf="@id/open"
    android:text="Send" />

<Button
    android:id="@+id/close"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@id/send"
    android:layout_toLeftOf="@id/send"
    android:text="Close" />

</RelativeLayout>

Here for Manifest: add to Application

// permission must be enabled complete
<manifest ....>

    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <application>


    </application>
</manifest>

Generate random colors (RGB)

Here:

def random_color():
    rgbl=[255,0,0]
    random.shuffle(rgbl)
    return tuple(rgbl)

The result is either red, green or blue. The method is not applicable to other sets of colors though, where you'd have to build a list of all the colors you want to choose from and then use random.choice to pick one at random.

How to stop a JavaScript for loop?

The logic is incorrect. It would always return the result of last element in the array.

remIndex = -1;

for (i = 0; i < remSize.length; i++) {      
    if (remSize[i].size == remData.size) {
        remIndex = i
        break;
    }
}

Better way to right align text in HTML Table

The <colgroup> and <col> tags that lives inside tables are designed for this purpose. If you have three columns in your table and want to align the third, add this after your opening <table> tag:

 <colgroup>
     <col />
     <col />
     <col class="your-right-align-class" />
 </colgroup>

along with the requisite CSS:

 .your-right-align-class { text-align: right; }

From the W3:

Definition and Usage

  • The <col> tag defines attribute values for one or more columns in a table.

  • The <col> tag is useful for applying styles to entire columns, instead of repeating the styles for each cell, for each row.

How does C compute sin() and other math functions?

Yes, there are software algorithms for calculating sin too. Basically, calculating these kind of stuff with a digital computer is usually done using numerical methods like approximating the Taylor series representing the function.

Numerical methods can approximate functions to an arbitrary amount of accuracy and since the amount of accuracy you have in a floating number is finite, they suit these tasks pretty well.

How to give a user only select permission on a database

create LOGIN guest WITH PASSWORD='guest@123', CHECK_POLICY = OFF;

Be sure when you want to exceute the following

DENY VIEW ANY DATABASE TO guest;

ALTER AUTHORIZATION ON DATABASE::BiddingSystemDB TO guest

Selected Database should be Master

Escaping a forward slash in a regular expression

Here are a few options:

  • In Perl, you can choose alternate delimiters. You're not confined to m//. You could choose another, such as m{}. Then escaping isn't necessary. As a matter of fact, Damian Conway in "Perl Best Practices" asserts that m{} is the only alternate delimiter that ought to be used, and this is reinforced by Perl::Critic (on CPAN). While you can get away with using a variety of alternate delimiter characters, // and {} seem to be the clearest to decipher later on. However, if either of those choices result in too much escaping, choose whichever one lends itself best to legibility. Common examples are m(...), m[...], and m!...!.

  • In cases where you either cannot or prefer not to use alternate delimiters, you can escape the forward slashes with a backslash: m/\/[^/]+$/ for example (using an alternate delimiter that could become m{/[^/]+$}, which may read more clearly). Escaping the slash with a backslash is common enough to have earned a name and a wikipedia page: Leaning Toothpick Syndrome. In regular expressions where there's just a single instance, escaping a slash might not rise to the level of being considered a hindrance to legibility, but if it starts to get out of hand, and if your language permits alternate delimiters as Perl does, that would be the preferred solution.

Solving Quadratic Equation

How about accepting complex roots as solutions?

import math

# User inserting the values of a, b and c

a = float(input("Insert coefficient a: "))
b = float(input("Insert coefficient b: "))
c = float(input("Insert coefficient c: "))

discriminant = b**2 - 4 * a * c

if discriminant >= 0:
    x_1=(-b+math.sqrt(discriminant))/2*a
    x_2=(-b-math.sqrt(discriminant))/2*a
else:
    x_1= complex((-b/(2*a)),math.sqrt(-discriminant)/(2*a))
    x_2= complex((-b/(2*a)),-math.sqrt(-discriminant)/(2*a))

if discriminant > 0:
    print("The function has two distinct real roots: ", x_1, " and ", x_2)
elif discriminant == 0:
    print("The function has one double root: ", x_1)
else:
    print("The function has two complex (conjugate) roots: ", x_1, " and ", x_2)

curl posting with header application/x-www-form-urlencoded

 $curl = curl_init();
 curl_setopt_array($curl, array(
            CURLOPT_URL => "http://example.com",
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_ENCODING => "",
            CURLOPT_MAXREDIRS => 10,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
            CURLOPT_CUSTOMREQUEST => "POST",
            CURLOPT_POSTFIELDS => "value1=111&value2=222",
            CURLOPT_HTTPHEADER => array(
                "cache-control: no-cache",
                "content-type: application/x-www-form-urlencoded"
            ),
        ));
 $response = curl_exec($curl);
 $err = curl_error($curl);

 curl_close($curl);

 if (!$err)
 {
      var_dump($response);
 }

Vue.js toggle class on click

This answer relevant for Vue.js version 2

<th 
  class="initial " 
  v-on:click="myFilter"
  v-bind:class="{ active: isActive }"
>
  <span class="wkday">M</span>
</th>

The rest of the answer by Douglas is still applicable (setting up the new Vue instance with isActive: false, etc).

Relevant docs: https://vuejs.org/v2/guide/class-and-style.html#Object-Syntax and https://vuejs.org/v2/guide/events.html#Method-Event-Handlers

How to solve "The specified service has been marked for deletion" error

This is what worked for me: - I hit the same issue: my service was stuck in 'marked for deletion'. - I opened services.msc My service did show up as running, although it was already uninstalled. - I clicked Stop Received an error message, saying the service is not in a state to receive control messages. Nevertheless, the service was stopped. - Closed services.msc. - Reopened services.msc. - The service was gone (no longer showing in the list of services).

(The environment was Windows 7.)

Run a command shell in jenkins

Go to Jenkins -> Manage Jenkins -> Configure System -> Global properties Check the box 'Environment variables' and add the JAVA_HOME path = "C:\Program Files\Java\jdk-10.0.1"

*Don't write bin at the end

Convert a string to int using sql query

Starting with SQL Server 2012, you could use TRY_PARSE or TRY_CONVERT.

SELECT TRY_PARSE(MyVarcharCol as int)

SELECT TRY_CONVERT(int, MyVarcharCol)

Delete cookie by name?

In order to delete a cookie set the expires date to something in the past. A function that does this would be.

var delete_cookie = function(name) {
    document.cookie = name + '=;expires=Thu, 01 Jan 1970 00:00:01 GMT;';
};

Then to delete a cookie named roundcube_sessauth just do.

delete_cookie('roundcube_sessauth');

Mongoose: findOneAndUpdate doesn't return updated document

So, "findOneAndUpdate" requires an option to return original document. And, the option is:

MongoDB shell

{returnNewDocument: true}

Ref: https://docs.mongodb.com/manual/reference/method/db.collection.findOneAndUpdate/

Mongoose

{new: true}

Ref: http://mongoosejs.com/docs/api.html#query_Query-findOneAndUpdate

Node.js MongoDB Driver API:

{returnOriginal: false}

Ref: http://mongodb.github.io/node-mongodb-native/3.0/api/Collection.html#findOneAndUpdate

perform an action on checkbox checked or unchecked event on html form

If you debug your code using developer tools, you will notice that this refers to the window object and not the input control. Consider using the passed in id to retrieve the input and check for checked value.

function doalert(id){
  if(document.getElementById(id).checked) {
    alert('checked');
  }else{
    alert('unchecked');
  }
}

Is div inside list allowed?

If you look at xhtml1-strict.dtd, you'll see

<!ELEMENT li %Flow;>
<!ENTITY % Flow "(#PCDATA | %block; | form | %inline; | %misc;)*">
<!ENTITY % block
     "p | %heading; | div | %lists; | %blocktext; | fieldset | table">

Thus div, p etc. can be inside li (according to XHTML 1.0 Strict DTD from w3.org).

How can I stop redis-server?

Another way could be:

ps -ef | grep -i 'redis-server'
kill -9 PID owned by redis

Works on *NIX & OSX

How to run a script at a certain time on Linux?

Look at the following:

echo "ls -l" | at 07:00

This code line executes "ls -l" at a specific time. This is an example of executing something (a command in my example) at a specific time. "at" is the command you were really looking for. You can read the specifications here:

http://manpages.ubuntu.com/manpages/precise/en/man1/at.1posix.html http://manpages.ubuntu.com/manpages/xenial/man1/at.1posix.html

Hope it helps!

Making a Bootstrap table column fit to content

_x000D_
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />_x000D_
_x000D_
<h5>Left</h5>_x000D_
<table class="table table-responsive">_x000D_
    <tbody>_x000D_
        <tr>_x000D_
            <th>Action</th>        _x000D_
            <th>Name</th>_x000D_
            <th>Payment Method</th>_x000D_
        </tr>_x000D_
        <tr>_x000D_
            <td  style="width:1px; white-space:nowrap;">_x000D_
                <a role="button" class="btn btn-default btn-xs" href="/Payments/View/NnrN_8tMB0CkVXt06nkrYg">View</a>_x000D_
                <a role="button" class="btn btn-primary btn-xs" href="/Payments/View/NnrN_8tMB0CkVXt06nkrYg">Edit</a>_x000D_
                <a role="button" class="btn btn-danger btn-xs" href="/Payments/View/NnrN_8tMB0CkVXt06nkrYg">Delete</a>                _x000D_
            </td>        _x000D_
            <td>Bart Foo</td>_x000D_
            <td>Visa</td>_x000D_
        </tr>_x000D_
    </tbody>_x000D_
</table>_x000D_
_x000D_
<h5>Right</h5>_x000D_
_x000D_
<table class="table table-responsive">_x000D_
    <tbody>_x000D_
        <tr>                    _x000D_
            <th>Name</th>_x000D_
            <th>Payment Method</th>_x000D_
            <th>Action</th>            _x000D_
        </tr>_x000D_
        <tr>_x000D_
_x000D_
            <td>Bart Foo</td>_x000D_
            <td>Visa</td>_x000D_
            <td  style="width:1px; white-space:nowrap;">_x000D_
                <a role="button" class="btn btn-default btn-xs" href="/Payments/View/NnrN_8tMB0CkVXt06nkrYg">View</a>_x000D_
                <a role="button" class="btn btn-primary btn-xs" href="/Payments/View/NnrN_8tMB0CkVXt06nkrYg">Edit</a>_x000D_
                <a role="button" class="btn btn-danger btn-xs" href="/Payments/View/NnrN_8tMB0CkVXt06nkrYg">Delete</a>                _x000D_
            </td>            _x000D_
        </tr>_x000D_
    </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

How do I declare a 2d array in C++ using new?

In C++11 it is possible:

auto array = new double[M][N]; 

This way, the memory is not initialized. To initialize it do this instead:

auto array = new double[M][N]();

Sample program (compile with "g++ -std=c++11"):

#include <iostream>
#include <utility>
#include <type_traits>
#include <typeinfo>
#include <cxxabi.h>
using namespace std;

int main()
{
    const auto M = 2;
    const auto N = 2;

    // allocate (no initializatoin)
    auto array = new double[M][N];

    // pollute the memory
    array[0][0] = 2;
    array[1][0] = 3;
    array[0][1] = 4;
    array[1][1] = 5;

    // re-allocate, probably will fetch the same memory block (not portable)
    delete[] array;
    array = new double[M][N];

    // show that memory is not initialized
    for(int r = 0; r < M; r++)
    {
        for(int c = 0; c < N; c++)
            cout << array[r][c] << " ";
        cout << endl;
    }
    cout << endl;

    delete[] array;

    // the proper way to zero-initialize the array
    array = new double[M][N]();

    // show the memory is initialized
    for(int r = 0; r < M; r++)
    {
        for(int c = 0; c < N; c++)
            cout << array[r][c] << " ";
        cout << endl;
    }

    int info;
    cout << abi::__cxa_demangle(typeid(array).name(),0,0,&info) << endl;

    return 0;
}

Output:

2 4 
3 5 

0 0 
0 0 
double (*) [2]

How to display a gif fullscreen for a webpage background?

You can set up a background with your GIF file and set the body this way:

body{
background-image:url('http://www.example.com/yourfile.gif');
background-position: center;
background-size: cover;
}

Change background image URL with your GIF. With background-position: center you can put the image to the center and with background-size: cover you set the picture to fit all the screen. You can also set background-size: contain if you want to fit the picture at 100% of the screen but without leaving any part of the picture without showing.

Here's more info about the property:

http://www.w3schools.com/cssref/css3_pr_background-size.asp

Hope it helps :)

Close a MessageBox after several seconds

DMitryG's code "get the return value of the underlying MessageBox" has a bug so the timerResult is never actually correctly returned (MessageBox.Show call returns AFTER OnTimerElapsed completes). My fix is below:

public class TimedMessageBox {
    System.Threading.Timer _timeoutTimer;
    string _caption;
    DialogResult _result;
    DialogResult _timerResult;
    bool timedOut = false;

    TimedMessageBox(string text, string caption, int timeout, MessageBoxButtons buttons = MessageBoxButtons.OK, DialogResult timerResult = DialogResult.None)
    {
        _caption = caption;
        _timeoutTimer = new System.Threading.Timer(OnTimerElapsed,
            null, timeout, System.Threading.Timeout.Infinite);
        _timerResult = timerResult;
        using(_timeoutTimer)
            _result = MessageBox.Show(text, caption, buttons);
        if (timedOut) _result = _timerResult;
    }

    public static DialogResult Show(string text, string caption, int timeout, MessageBoxButtons buttons = MessageBoxButtons.OK, DialogResult timerResult = DialogResult.None) {
        return new TimedMessageBox(text, caption, timeout, buttons, timerResult)._result;
    }

    void OnTimerElapsed(object state) {
        IntPtr mbWnd = FindWindow("#32770", _caption); // lpClassName is #32770 for MessageBox
        if(mbWnd != IntPtr.Zero)
            SendMessage(mbWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
        _timeoutTimer.Dispose();
        timedOut = true;
    }

    const int WM_CLOSE = 0x0010;
    [System.Runtime.InteropServices.DllImport("user32.dll", SetLastError = true, CharSet = System.Runtime.InteropServices.CharSet.Auto)]
    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
    [System.Runtime.InteropServices.DllImport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]
    static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
}

Does C# have a String Tokenizer like Java's?

You could use String.Split method.

class ExampleClass
{
    public ExampleClass()
    {
        string exampleString = "there is a cat";
        // Split string on spaces. This will separate all the words in a string
        string[] words = exampleString.Split(' ');
        foreach (string word in words)
        {
            Console.WriteLine(word);
            // there
            // is
            // a
            // cat
        }
    }
}

For more information see Sam Allen's article about splitting strings in c# (Performance, Regex)

MySql server startup error 'The server quit without updating PID file '

I was trying to reinstall mysql, and I actually forgot to stop the server from my old install. To solve that, ps -ax | grep mysql, then kill [whatever PIDs]. But, then again, it's different for everybody. Like the other answers said, go to /usr/local/var/mysql/ and check your .err log file.

How do I completely remove root password

Did you try passwd -d root? Most likely, this will do what you want.


You can also manually edit /etc/shadow: (Create a backup copy. Be sure that you can log even if you mess up, for example from a rescue system.) Search for "root". Typically, the root entry looks similar to

root:$X$SK5xfLB1ZW:0:0...

There, delete the second field (everything between the first and second colon):

root::0:0...

Some systems will make you put an asterisk (*) in the password field instead of blank, where a blank field would allow no password (CentOS 8 for example)

root:*:0:0...

Save the file, and try logging in as root. It should skip the password prompt. (Like passwd -d, this is a "no password" solution. If you are really looking for a "blank password", that is "ask for a password, but accept if the user just presses Enter", look at the manpage of mkpasswd, and use mkpasswd to create the second field for the /etc/shadow.)

Find index of a value in an array

Just posted my implementation of IndexWhere() extension method (with unit tests):

http://snipplr.com/view/53625/linq-index-of-item--indexwhere/

Example usage:

int index = myList.IndexWhere(item => item.Something == someOtherThing);

What Java FTP client library should I use?

Apache commons-nets get updates more frequently recently, while Enterprise DT library seems to update even more frequently.