Programs & Examples On #Prefuse

Prefuse is a set of software tools for creating rich interactive data visualizations in the Java programming language.

Android check null or empty string in Android

Checking for empty string if it is equal to null, length is zero or containing "null" string

public static boolean isEmptyString(String text) {
        return (text == null || text.trim().equals("null") || text.trim()
                .length() <= 0);
    }

Column count doesn't match value count at row 1

  1. you missed the comma between two values or column name
  2. you put extra values or an extra column name

How to create Windows EventLog source from command line?

Try "eventcreate.exe"

An example:

eventcreate /ID 1 /L APPLICATION /T INFORMATION  /SO MYEVENTSOURCE /D "My first log"

This will create a new event source named MYEVENTSOURCE under APPLICATION event log as INFORMATION event type.

I think this utility is included only from XP onwards.

Further reading

Rails: Can't verify CSRF token authenticity when making a POST request

If you want to exclude the sample controller's sample action

class TestController < ApplicationController
  protect_from_forgery :except => [:sample]

  def sample
     render json: @hogehoge
  end
end

You can to process requests from outside without any problems.

Is there a way to know your current username in mysql?

You can also use : mysql> select user,host from mysql.user;

+---------------+-------------------------------+
| user          | host                          |
+---------------+-------------------------------+
| fkernel       | %                             |
| nagios        | %                             |
| readonly      | %                             |
| replicant     | %                             |
| reporting     | %                             |
| reporting_ro  | %                             |
| nagios        | xx.xx.xx.xx                 |
| haproxy_root  | xx.xx.xx.xx
| root          | 127.0.0.1                     |
| nagios        | localhost                     |
| root          | localhost                     |
+---------------+-------------------------------+

Problems with installation of Google App Engine SDK for php in OS X

It's likely that the download was corrupted if you are getting an error with the disk image. Go back to the downloads page at https://developers.google.com/appengine/downloads and look at the SHA1 checksum. Then, go to your Terminal app on your mac and run the following:

openssl sha1 [put the full path to the file here without brackets] 

For example:

openssl sha1 /Users/me/Desktop/myFile.dmg 

If you get a different value than the one on the Downloads page, you know your file is not properly downloaded and you should try again.

Changing background color of ListView items on Android

You can do This.

 final List<String> fruits_list = new ArrayList<String>(Arrays.asList(fruits));

    // Create an ArrayAdapter from List
    final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>
            (this, android.R.layout.simple_list_item_1, fruits_list){
        @Override
        public View getView(int position, View convertView, ViewGroup parent){
            // Get the current item from ListView
            View view = super.getView(position,convertView,parent);
            if(position %2 == 1)
            {
                // Set a background color for ListView regular row/item
                view.setBackgroundColor(Color.parseColor("#FFB6B546"));
            }
            else
            {
                // Set the background color for alternate row/item
                view.setBackgroundColor(Color.parseColor("#FFCCCB4C"));
            }
            return view;
        }
    };

    // DataBind ListView with items from ArrayAdapter
    lv.setAdapter(arrayAdapter);
}

}

Force GUI update from UI Thread

Call label.Invalidate and then label.Update() - usually the update only happens after you exit the current function but calling Update forces it to update at that specific place in code. From MSDN:

The Invalidate method governs what gets painted or repainted. The Update method governs when the painting or repainting occurs. If you use the Invalidate and Update methods together rather than calling Refresh, what gets repainted depends on which overload of Invalidate you use. The Update method just forces the control to be painted immediately, but the Invalidate method governs what gets painted when you call the Update method.

Printing a char with printf

In C char gets promoted to int in expressions. That pretty much explains every question, if you think about it.

Source: The C Programming Language by Brian W.Kernighan and Dennis M.Ritchie

A must read if you want to learn C.

Also see this stack overflow page, where people much more experienced then me can explain it much better then I ever can.

How to alter a column and change the default value?

If you want to add a default value for the already created column, this works for me:

ALTER TABLE Persons
ALTER credit SET DEFAULT 0.0;

Keep values selected after form submission

To avoid many if-else structures, let JavaScript do the trick automatically:

<select name="name" id="name">
   <option value="a">a</option>
   <option value="b">b</option>
</select>

<script type="text/javascript">
  document.getElementById('name').value = "<?php echo $_GET['name'];?>";
</script>

<select name="location" id="location">
  <option value="x">x</option>
  <option value="y">y</option>
</select>

<script type="text/javascript">
  document.getElementById('location').value = "<?php echo $_GET['location'];?>";
</script>

How to create a Date in SQL Server given the Day, Month and Year as Integers

select convert(varchar(11), transfer_date, 106)

got me my desired result of date formatted as 07 Mar 2018

My column 'transfer_date' is a datetime type column and I am using SQL Server 2017 on azure

How to define an empty object in PHP

Use a generic object and map key value pairs to it.

$oVal = new stdClass();
$oVal->key = $value

Or cast an array into an object

$aVal = array( 'key'=>'value' );
$oVal = (object) $aVal;

Scheduling recurring task in Android

Timer

As mentioned on the javadocs you are better off using a ScheduledThreadPoolExecutor.

ScheduledThreadPoolExecutor

Use this class when your use case requires multiple worker threads and the sleep interval is small. How small ? Well, I'd say about 15 minutes. The AlarmManager starts schedule intervals at this time and it seems to suggest that for smaller sleep intervals this class can be used. I do not have data to back the last statement. It is a hunch.

Service

Your service can be closed any time by the VM. Do not use services for recurring tasks. A recurring task can start a service, which is another matter entirely.

BroadcastReciever with AlarmManager

For longer sleep intervals (>15 minutes), this is the way to go. AlarmManager already has constants ( AlarmManager.INTERVAL_DAY ) suggesting that it can trigger tasks several days after it has initially been scheduled. It can also wake up the CPU to run your code.

You should use one of those solutions based on your timing and worker thread needs.

Meaning of "referencing" and "dereferencing" in C

Referencing means taking the address of an existing variable (using &) to set a pointer variable. In order to be valid, a pointer has to be set to the address of a variable of the same type as the pointer, without the asterisk:

int  c1;
int* p1;
c1 = 5;
p1 = &c1;
//p1 references c1

Dereferencing a pointer means using the * operator (asterisk character) to retrieve the value from the memory address that is pointed by the pointer: NOTE: The value stored at the address of the pointer must be a value OF THE SAME TYPE as the type of variable the pointer "points" to, but there is no guarantee this is the case unless the pointer was set correctly. The type of variable the pointer points to is the type less the outermost asterisk.

int n1;
n1 = *p1;

Invalid dereferencing may or may not cause crashes:

  • Dereferencing an uninitialized pointer can cause a crash
  • Dereferencing with an invalid type cast will have the potential to cause a crash.
  • Dereferencing a pointer to a variable that was dynamically allocated and was subsequently de-allocated can cause a crash
  • Dereferencing a pointer to a variable that has since gone out of scope can also cause a crash.

Invalid referencing is more likely to cause compiler errors than crashes, but it's not a good idea to rely on the compiler for this.

References:

http://www.codingunit.com/cplusplus-tutorial-pointers-reference-and-dereference-operators

& is the reference operator and can be read as “address of”.
* is the dereference operator and can be read as “value pointed by”.

http://www.cplusplus.com/doc/tutorial/pointers/

& is the reference operator    
* is the dereference operator

http://en.wikipedia.org/wiki/Dereference_operator

The dereference operator * is also called the indirection operator.

How to set selected value from Combobox?

try this

combobox.SelectedIndex = BindingSource.Item(9) where "9 = colum name 9 from table"

How to convert minutes to hours/minutes and add various time values together using jQuery?

var timeConvert = function(n){
 var minutes = n%60
 var hours = (n - minutes) / 60
 console.log(hours + ":" + minutes)
}
timeConvert(65)

this will log 1:5 to the console. It is a short and simple solution that should be easy to understand and no jquery plugin is necessary...

What special characters must be escaped in regular expressions?

Maybe an old thread, but this code might be useful to visitors who want to create without regex

def listToString(s):  
    
    # initialize an empty string 
    str1 = "" 
    
    # return string   
    return (str1.join(s))


r = "Hello! How are you? *Smiling_Face* *Heart* erwer"
r1 = list(r)
i = 0
r2 = list()
start = True

for string in r1:
    if string == "*":
        if(start):
            start = False
        else:
            start = True
    else:
        if(start):
            r2.append(string)
        else:
            print("skipped" + string)
            
 
print(listToString(r2))

Why does Eclipse Java Package Explorer show question mark on some classes?

It means the class is not yet added to the repository.

If your project was checked-out (most probably a CVS project) and you added a new class file, it will have the ? icon.

For other CVS Label Decorations, check http://help.eclipse.org/help33/index.jsp?topic=/org.eclipse.platform.doc.user/reference/ref-cvs-decorations.htm

fe_sendauth: no password supplied

I just put --password flag into my command and after hitting Enter it asked me for password, which I supplied.

How do I get column datatype in Oracle with PL-SQL with low privileges?

select t.data_type 
  from user_tab_columns t 
 where t.TABLE_NAME = 'xxx' 
   and t.COLUMN_NAME='aaa'

NuGet auto package restore does not work with MSBuild

Nuget's Automatic Package Restore is a feature of the Visual Studio (starting in 2013), not MSBuild. You'll have to run nuget.exe restore if you want to restore packages from the command line.

You can also use the Enable Nuget Package Restore feature, but this is no longer recommended by the nuget folks because it makes intrusive changes to the project files and may cause problems if you build those projects in another solution.

font awesome icon in select option

When using a <select> tag that shows all options, here's a work around using <div> instead:

HTML

<div id='sectionOptionsSelect' size='5' class='block1'
        style='visibility: hidden; border: 1px solid gray; padding: 5px; '>
    <span class='addPageBreakAbove'>Add Page Break Above</span>
    <span class='addPageBreakBelow'>Add Page Break Below</span>
    <span class='removeSection'>
        <label class='fa fa-window-close'
               style='font-size: 25px; color: red; background: white; '></label>
        Remove Section</span>
</div>

Supporting JS

$('#sectionOptionsSelect span').hover(function () {

    $(this).css('background', '#c0ec67');

}, function () {

    $(this).css('background', 'transparent');
});

$('.removeSection').click(function () {

    alert('removeSection');
});

CSS

#sectionOptionsSelect span {
    display: block;
}

How to View Oracle Stored Procedure using SQLPlus?

check your casing, the name is typically stored in upper case

SELECT * FROM all_source WHERE name = 'DAILY_UPDATE' ORDER BY TYPE, LINE;

MYSQL order by both Ascending and Descending sorting

You can do that in this way:

ORDER BY `products`.`product_category_id` DESC ,`naam` ASC

Have a look at ORDER BY Optimization

UTF-8 encoding problem in Spring MVC

in your dispatcher servlet context xml, you have to add a propertie "<property name="contentType" value="text/html;charset=UTF-8" />" on your viewResolver bean. we are using freemarker for views.

it looks something like this:

<bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
       ...
       <property name="contentType" value="text/html;charset=UTF-8" />
       ...
</bean>

Detecting a redirect in ajax request?

The AJAX request never has the opportunity to NOT follow the redirect (i.e., it must follow the redirect). More information can be found in this answer https://stackoverflow.com/a/2573589/965648

How can I compare two lists in python and return matches

you can | for set union and & for set intersection.
for example:

    set1={1,2,3}
    set2={3,4,5}
    print(set1&set2)
    output=3

    set1={1,2,3}
    set2={3,4,5}
    print(set1|set2)
    output=1,2,3,4,5

curly braces in the answer.

Dump all documents of Elasticsearch

You can also dump elasticsearch data in JSON format by http request: https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-scroll.html
CURL -XPOST 'https://ES/INDEX/_search?scroll=10m'
CURL -XPOST 'https://ES/_search/scroll' -d '{"scroll": "10m", "scroll_id": "ID"}'

jQuery change method on input type="file"

I could not get IE8+ to work by adding a jQuery event handler to the file input type. I had to go old-school and add the the onchange="" attribute to the input tag:

<input type='file' onchange='getFilename(this)'/>

function getFileName(elm) {
   var fn = $(elm).val();
   ....
}

EDIT:

function getFileName(elm) {
   var fn = $(elm).val();
   var filename = fn.match(/[^\\/]*$/)[0]; // remove C:\fakename
   alert(filename);
}

Select Pandas rows based on list index

you can also use iloc:

df.iloc[[1,3],:]

This will not work if the indexes in your dataframe do not correspond to the order of the rows due to prior computations. In that case use:

df.index.isin([1,3])

... as suggested in other responses.

How can I disable the Maven Javadoc plugin from the command line?

It seems, that the simple way

-Dmaven.javadoc.skip=true

does not work with the release-plugin. in this case you have to pass the parameter as an "argument"

mvn release:perform -Darguments="-Dmaven.javadoc.skip=true"

Easier way to create circle div than using an image?

It is actually possible.

See: CSS Tip: How to Make Circles Without Images. See demo.

But be warned, It has serious disadvantages in terms of compatibility basically, you are making a cat bark.

See it working here

As you will see you just have to set up the height and width to half the border-radius

Good luck!

What is the runtime performance cost of a Docker container?

Docker isn't virtualization, as such -- instead, it's an abstraction on top of the kernel's support for different process namespaces, device namespaces, etc.; one namespace isn't inherently more expensive or inefficient than another, so what actually makes Docker have a performance impact is a matter of what's actually in those namespaces.


Docker's choices in terms of how it configures namespaces for its containers have costs, but those costs are all directly associated with benefits -- you can give them up, but in doing so you also give up the associated benefit:

  • Layered filesystems are expensive -- exactly what the costs are vary with each one (and Docker supports multiple backends), and with your usage patterns (merging multiple large directories, or merging a very deep set of filesystems will be particularly expensive), but they're not free. On the other hand, a great deal of Docker's functionality -- being able to build guests off other guests in a copy-on-write manner, and getting the storage advantages implicit in same -- ride on paying this cost.
  • DNAT gets expensive at scale -- but gives you the benefit of being able to configure your guest's networking independently of your host's and have a convenient interface for forwarding only the ports you want between them. You can replace this with a bridge to a physical interface, but again, lose the benefit.
  • Being able to run each software stack with its dependencies installed in the most convenient manner -- independent of the host's distro, libc, and other library versions -- is a great benefit, but needing to load shared libraries more than once (when their versions differ) has the cost you'd expect.

And so forth. How much these costs actually impact you in your environment -- with your network access patterns, your memory constraints, etc -- is an item for which it's difficult to provide a generic answer.

Finding height in Binary Search Tree

The problem lies in your base case.

"The height of a tree is the length of the path from the root to the deepest node in the tree. A (rooted) tree with only a node (the root) has a height of zero." - Wikipedia

If there is no node, you want to return -1 not 0. This is because you are adding 1 at the end.

So if there isn't a node, you return -1 which cancels out the +1.

int findHeight(TreeNode<T> aNode) {
    if (aNode == null) {
        return -1;
    }

    int lefth = findHeight(aNode.left);
    int righth = findHeight(aNode.right);

    if (lefth > righth) {
        return lefth + 1;
    } else {
        return righth + 1;
    }
}

Get selected value in dropdown list using JavaScript

I don't know if I'm the one that doesn't get the question right, but this just worked for me: Using an onchange() event in your html, eg.

<select id="numberToSelect" onchange="selectNum">
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
</select>

//javascript

function sele(){
    var strUser = numberToSelect.value;
}

This will give you whatever value is on the select dropdown per click

Why dict.get(key) instead of dict[key]?

One difference, that can be an advantage, is that if we are looking for a key that doesn't exist we will get None, not like when we use the brackets notation, in which case we will get an error thrown:

print(dictionary.get("address")) # None
print(dictionary["address"]) # throws KeyError: 'address'

Last thing that is cool about the get method, is that it receives an additional optional argument for a default value, that is if we tried to get the score value of a student, but the student doesn't have a score key we can get a 0 instead.

So instead of doing this (or something similar):

score = None
try:
    score = dictionary["score"]
except KeyError:
    score = 0

We can do this:

score = dictionary.get("score", 0)
# score = 0

How do I load a file into the python console?

If you're using IPython, you can simply run:

%load path/to/your/file.py

See http://ipython.org/ipython-doc/rel-1.1.0/interactive/tutorial.html

Custom Adapter for List View

It is very simple.

import android.content.Context;
import android.content.DialogInterface;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;

/**
 * Created by Belal on 9/14/2017.
 */

//we need to extend the ArrayAdapter class as we are building an adapter
public class MyListAdapter extends ArrayAdapter<Hero> {

    //the list values in the List of type hero 
    List<Hero> heroList;

    //activity context 
    Context context;

    //the layout resource file for the list items
    int resource;

    //constructor initializing the values 
    public MyListAdapter(Context context, int resource, List<Hero> heroList) {
        super(context, resource, heroList);
        this.context = context;
        this.resource = resource;
        this.heroList = heroList;
    }

    //this will return the ListView Item as a View
    @NonNull
    @Override
    public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {

        //we need to get the view of the xml for our list item
        //And for this we need a layoutinflater
        LayoutInflater layoutInflater = LayoutInflater.from(context);

        //getting the view
        View view = layoutInflater.inflate(resource, null, false);

        //getting the view elements of the list from the view
        ImageView imageView = view.findViewById(R.id.imageView);
        TextView textViewName = view.findViewById(R.id.textViewName);
        TextView textViewTeam = view.findViewById(R.id.textViewTeam);
        Button buttonDelete = view.findViewById(R.id.buttonDelete);

        //getting the hero of the specified position
        Hero hero = heroList.get(position);

        //adding values to the list item 
        imageView.setImageDrawable(context.getResources().getDrawable(hero.getImage()));
        textViewName.setText(hero.getName());
        textViewTeam.setText(hero.getTeam());

        //adding a click listener to the button to remove item from the list
        buttonDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //we will call this method to remove the selected value from the list
                //we are passing the position which is to be removed in the method 
                removeHero(position);
            }
        });

        //finally returning the view
        return view;
    }

    //this method will remove the item from the list 
    private void removeHero(final int position) {
        //Creating an alert dialog to confirm the deletion
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setTitle("Are you sure you want to delete this?");

        //if the response is positive in the alert 
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

                //removing the item 
                heroList.remove(position);

                //reloading the list 
                notifyDataSetChanged();
            }
        });

        //if response is negative nothing is being done 
        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

            }
        });

        //creating and displaying the alert dialog 
        AlertDialog alertDialog = builder.create();
        alertDialog.show();
    }
}

Source: Custom ListView Android Tutorial

You need to use a Theme.AppCompat theme (or descendant) with this activity

Change the theme of the desired Activity. This works for me:

<activity
            android:name="HomeActivity"
            android:screenOrientation="landscape"
            android:theme="@style/Theme.AppCompat.Light"
            android:windowSoftInputMode="stateHidden" />

List all column except for one in R

In addition to tcash21's numeric indexing if OP may have been looking for negative indexing by name. Here's a few ways I know, some are risky than others to use:

mtcars[, -which(names(mtcars) == "carb")]  #only works on a single column
mtcars[, names(mtcars) != "carb"]          #only works on a single column
mtcars[, !names(mtcars) %in% c("carb", "mpg")] 
mtcars[, -match(c("carb", "mpg"), names(mtcars))] 
mtcars2 <- mtcars; mtcars2$hp <- NULL         #lost column (risky)


library(gdata) 
remove.vars(mtcars2, names=c("mpg", "carb"), info=TRUE) 

Generally I use:

mtcars[, !names(mtcars) %in% c("carb", "mpg")] 

because I feel it's safe and efficient.

How to combine multiple inline style objects?

To Expand on what @PythonIsGreat said, I create a global function that will do it for me:

var css = function(){
    var args = $.merge([true, {}], Array.prototype.splice.call(arguments, 0));
    return $.extend.apply(null, args);
}

This deeply extends the objects into a new object and allows for a variable number of objects as parameters. This allows you to do something like this:

return(
<div style={css(styles.base, styles.first, styles.second,...)} ></div>
);

var styles = {
  base:{
    //whatever
  },
  first:{
    //whatever
  },
  second:{
    //whatever
  }
}

How to execute IN() SQL queries with Spring's JDBCTemplate effectively?

If you get an exception for : Invalid column type

Please use getNamedParameterJdbcTemplate() instead of getJdbcTemplate()

 List<Foo> foo = getNamedParameterJdbcTemplate().query("SELECT * FROM foo WHERE a IN (:ids)",parameters,
 getRowMapper());

Note that the second two arguments are swapped around.

How to make/get a multi size .ico file?

I found an app for Mac OSX called ICOBundle that allows you to easily drop a selection of ico files in different sizes onto the ICOBundle.app, prompts you for a folder destination and file name, and it creates the multi-icon .ico file.

Now if it were only possible to mix-in an animated gif version into that one file it'd be a complete icon set, sadly not possible and requires a separate file and code snippet.

How to parse/read a YAML file into a Python object?

If your YAML file looks like this:

# tree format
treeroot:
    branch1:
        name: Node 1
        branch1-1:
            name: Node 1-1
    branch2:
        name: Node 2
        branch2-1:
            name: Node 2-1

And you've installed PyYAML like this:

pip install PyYAML

And the Python code looks like this:

import yaml
with open('tree.yaml') as f:
    # use safe_load instead load
    dataMap = yaml.safe_load(f)

The variable dataMap now contains a dictionary with the tree data. If you print dataMap using PrettyPrint, you will get something like:

{
    'treeroot': {
        'branch1': {
            'branch1-1': {
                'name': 'Node 1-1'
            },
            'name': 'Node 1'
        },
        'branch2': {
            'branch2-1': {
                'name': 'Node 2-1'
            },
            'name': 'Node 2'
        }
    }
}

So, now we have seen how to get data into our Python program. Saving data is just as easy:

with open('newtree.yaml', "w") as f:
    yaml.dump(dataMap, f)

You have a dictionary, and now you have to convert it to a Python object:

class Struct:
    def __init__(self, **entries): 
        self.__dict__.update(entries)

Then you can use:

>>> args = your YAML dictionary
>>> s = Struct(**args)
>>> s
<__main__.Struct instance at 0x01D6A738>
>>> s...

and follow "Convert Python dict to object".

For more information you can look at pyyaml.org and this.

An efficient way to Base64 encode a byte array?

Byte[] -> String: use system.convert.tobase64string

Convert.ToBase64String(byte[] data)

String -> Byte[]: use system.convert.frombase64string

Convert.FromBase64String(string data)

How to insert Records in Database using C# language?

sql = "insert into Main (Firt Name, Last Name) values(textbox2.Text,textbox3.Text)";

(Firt Name) is not a valid field. It should be FirstName or First_Name. It may be your problem.

Reducing video size with same format and reducing frame size

ffmpeg provides this functionality. All you need to do is run someting like

ffmpeg -i <inputfilename> -s 640x480 -b 512k -vcodec mpeg1video -acodec copy <outputfilename>

For newer versions of ffmpeg you need to change -b to -b:v:

ffmpeg -i <inputfilename> -s 640x480 -b:v 512k -vcodec mpeg1video -acodec copy <outputfilename>

to convert the input video file to a video with a size of 640 x 480 and a bitrate of 512 kilobits/sec using the MPEG 1 video codec and just copying the original audio stream. Of course, you can plug in any values you need and play around with the size and bitrate to achieve the quality/size tradeoff you are looking for. There are also a ton of other options described in the documentation

Run ffmpeg -formats or ffmpeg -codecs for a list of all of the available formats and codecs. If you don't have to target a specific codec for the final output, you can achieve better compression ratios with minimal quality loss using a state of the art codec like H.264.

time delayed redirect?

Edit:

The problem i face is that HTML5 is all on one index page. So i need the timer to start on click of the blog link.

Try calling the setTimeout inside a click handler on the blog link,

$('#blogLink').click (function (e) {
   e.preventDefault(); //will stop the link href to call the blog page

   setTimeout(function () {
       window.location.href = "blog.html"; //will redirect to your blog page (an ex: blog.html)
    }, 2000); //will call the function after 2 secs.

});

Try using setTimeout function like below,

setTimeout(function () {
   window.location.href = "blog.html"; //will redirect to your blog page (an ex: blog.html)
}, 2000); //will call the function after 2 secs.

How do I correctly setup and teardown for my pytest class with tests?

Your code should work just as you expect it to if you add @classmethod decorators.

@classmethod 
def setup_class(cls):
    "Runs once per class"

@classmethod 
def teardown_class(cls):
    "Runs at end of class"

See http://pythontesting.net/framework/pytest/pytest-xunit-style-fixtures/

Fatal error: Cannot use object of type stdClass as array in

Controller (Example: User.php)

<?php
defined('BASEPATH') or exit('No direct script access allowed');

class Users extends CI_controller
{

    // Table
    protected  $table = 'users';

    function index()
    {
        $data['users'] = $this->model->ra_object($this->table);
        $this->load->view('users_list', $data);
    }
}

View (Example: users_list.php)

<table>
    <thead>
        <tr>
            <th>Name</th>
            <th>Surname</th>
        </tr>
    </thead>

    <tbody>
        <?php foreach($users as $user) : ?>
            <tr>
            <td><?php echo $user->name; ?></td>
            <td><?php echo $user->surname; ?></th>
        </tr>
        <?php endforeach; ?>
    </tbody>
</table>
<!-- // User table -->

How to do logging in React Native?

Something that just came out about a month ago is "Create React Native App," an awesome boilerplate that allows you (with minimal effort) to show what your app looks like live on your mobile device (ANY with a camera) using the Expo app. It not only has live updates, but it will allow you to see the console logs in your terminal just like when developing for the web, rather than having to use the browser like we did with React Native before.

You would, of course, have to make a new project with that boilerplate... but if you need to migrate your files over, that shouldn't be a problem. Give it a shot.

Edit: Actually it doesn't even require a camera. I said that for scanning a QR code, but you can also type out something to sync it up with your server, not just a QR code.

Laravel Eloquent groupBy() AND also return count of each group

Works that way as well, a bit more tidy. getQuery() just returns the underlying builder, which already contains the table reference.

$browser_total_raw = DB::raw('count(*) as total');
$user_info = Usermeta::getQuery()
                     ->select('browser', $browser_total_raw)
                     ->groupBy('browser')
                     ->pluck('total','browser');

Find the greatest number in a list of numbers

This approach is without using max() function

a = [1,2,3,4,6,7,99,88,999]
max_num = 0
for i in a:
    if i > max_num:
        max_num = i
print(max_num)

Also if you want to find the index of the resulting max,

print(a.index(max_num))

Direct approach by using function max()

max() function returns the item with the highest value, or the item with the highest value in an iterable

Example: when you have to find max on integers/numbers

a = (1, 5, 3, 9)
print(max(a))
>> 9

Example: when you have string

x = max("Mike", "John", "Vicky")
print(x)
>> Vicky

It basically returns the name with the highest value, ordered alphabetically.

T-SQL: Opposite to string concatenation - how to split string into multiple records

I use this function (SQL Server 2005 and above).

create function [dbo].[Split]
(
    @string nvarchar(4000),
    @delimiter nvarchar(10)
)
returns @table table
(
    [Value] nvarchar(4000)
)
begin
    declare @nextString nvarchar(4000)
    declare @pos int, @nextPos int

    set @nextString = ''
    set @string = @string + @delimiter

    set @pos = charindex(@delimiter, @string)
    set @nextPos = 1
    while (@pos <> 0)
    begin
        set @nextString = substring(@string, 1, @pos - 1)

        insert into @table
        (
            [Value]
        )
        values
        (
            @nextString
        )

        set @string = substring(@string, @pos + len(@delimiter), len(@string))
        set @nextPos = @pos
        set @pos = charindex(@delimiter, @string)
    end
    return
end

Print PDF directly from JavaScript

I used this function to download pdf stream from server.

function printPdf(url) {
        var iframe = document.createElement('iframe');
        // iframe.id = 'pdfIframe'
        iframe.className='pdfIframe'
        document.body.appendChild(iframe);
        iframe.style.display = 'none';
        iframe.onload = function () {
            setTimeout(function () {
                iframe.focus();
                iframe.contentWindow.print();
                URL.revokeObjectURL(url)
                // document.body.removeChild(iframe)
            }, 1);
        };
        iframe.src = url;
        // URL.revokeObjectURL(url)
    }

Install php-zip on php 5.6 on Ubuntu

Try either

  • sudo apt-get install php-zip or
  • sudo apt-get install php5.6-zip

Then, you might have to restart your web server.

  • sudo service apache2 restart or
  • sudo service nginx restart

If you are installing on centos or fedora OS then use yum in place of apt-get. example:-

sudo yum install php-zip or sudo yum install php5.6-zip and sudo service httpd restart

What is pluginManagement in Maven's pom.xml?

The difference between <pluginManagement/> and <plugins/> is that a <plugin/> under:

  • <pluginManagement/> defines the settings for plugins that will be inherited by modules in your build. This is great for cases where you have a parent pom file.

  • <plugins/> is a section for the actual invocation of the plugins. It may or may not be inherited from a <pluginManagement/>.

You don't need to have a <pluginManagement/> in your project, if it's not a parent POM. However, if it's a parent pom, then in the child's pom, you need to have a declaration like:

<plugins>
    <plugin>
        <groupId>com.foo</groupId>
        <artifactId>bar-plugin</artifactId>
    </plugin>
</plugins>

Notice how you aren't defining any configuration. You can inherit it from the parent, unless you need to further adjust your invocation as per the child project's needs.

For more specific information, you can check:

Mean Squared Error in Numpy?

Just for kicks

mse = (np.linalg.norm(A-B)**2)/len(A)

Git removing upstream from local repository

In git version 2.14.3,

You can remove upstream using

git branch --unset-upstream

The above command will also remove the tracking stream branch, hence if you want to rebase from repository you have use

git rebase origin master 

instead of git pull --rebase

Fast Bitmap Blur For Android SDK

We tried to implement RenderScript blur like mentioned above in different answers. We were limited to use the v8 RenderScript version and that caused us a lot of trouble.

  • Samsung S3 crashed randomly whenever we tried to use the renderscript
  • Other devices (across different APIs) randomly showed different color issues

I want to share our dirty Java-only version which is slow and should be done on a separate thread and, if possible, before usage and therefore persisted.

private final Paint mPaint = new Paint();

public Bitmap blur(final String pathToBitmap) {
    final BitmapFactory.Options options = new BitmapFactory.Options();
    final Bitmap normalOne = BitmapFactory.decodeFile(pathToBitmap, options);
    final Bitmap resultBitmap = Bitmap.createBitmap(options.outWidth, options.outHeight, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(resultBitmap);
    mPaint.setAlpha(180);
    canvas.drawBitmap(normalOne, 0, 0, mPaint);
    int blurRadius = 12;
    for (int row = -blurRadius; row < blurRadius; row += 2) {
        for (int col = -blurRadius; col < blurRadius; col += 2) {
            if (col * col + row * row <= blurRadius * blurRadius) {
                mPaint.setAlpha((blurRadius * blurRadius) / ((col * col + row * row) + 1) * 2);
                canvas.drawBitmap(normalOne, row, col, mPaint);
            }
        }
    }
    normalOne.recycle();
    return resultBitmap;
}

This solution is far from perfect but creates a reasonable blur effect based on the fact, that it draws highly transparent version of the same image on top of a barely transparent "sharp" version. The alpha depends on the distance to the origin.

You can adjust some "magic numbers" to your needs. I just wanted to share that "solution" for everybody who has issues with the v8 support version of RenderScript.

Check if string contains only whitespace

Check the length of the list given by of split() method.

if len(your_string.split()==0:
     print("yes")

Or Compare output of strip() method with null.

if your_string.strip() == '':
     print("yes")

Date to milliseconds and back to date in Swift

//Date to milliseconds
func currentTimeInMiliseconds() -> Int {
    let currentDate = Date()
    let since1970 = currentDate.timeIntervalSince1970
    return Int(since1970 * 1000)
}

//Milliseconds to date
extension Int {
    func dateFromMilliseconds() -> Date {
        return Date(timeIntervalSince1970: TimeInterval(self)/1000)
    }
}

I removed seemingly useless conversion via string and all those random !.

No mapping found for HTTP request with URI.... in DispatcherServlet with name

Removing the Tomcat Server and adding new tomcat configuration in Eclipse resolved issue for me.

How to get Node.JS Express to listen only on localhost?

Thanks for the info, think I see the problem. This is a bug in hive-go that only shows up when you add a host. The last lines of it are:

app.listen(3001);
console.log("... port %d in %s mode", app.address().port, app.settings.env);

When you add the host on the first line, it is crashing when it calls app.address().port.

The problem is the potentially asynchronous nature of .listen(). Really it should be doing that console.log call inside a callback passed to listen. When you add the host, it tries to do a DNS lookup, which is async. So when that line tries to fetch the address, there isn't one yet because the DNS request is running, so it crashes.

Try this:

app.listen(3001, 'localhost', function() {
  console.log("... port %d in %s mode", app.address().port, app.settings.env);
});

How to fix "Incorrect string value" errors?

First check if your default_character_set_name is utf8.

SELECT default_character_set_name FROM information_schema.SCHEMATA S WHERE schema_name = "DBNAME";

If the result is not utf8 you must convert your database. At first you must save a dump.

To change the character set encoding to UTF-8 for all of the tables in the specified database, type the following command at the command line. Replace DBNAME with the database name:

mysql --database=DBNAME -B -N -e "SHOW TABLES" | awk '{print "SET foreign_key_checks = 0; ALTER TABLE", $1, "CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci; SET foreign_key_checks = 1; "}' | mysql --database=DBNAME

To change the character set encoding to UTF-8 for the database itself, type the following command at the mysql> prompt. Replace DBNAME with the database name:

ALTER DATABASE DBNAME CHARACTER SET utf8 COLLATE utf8_general_ci;

You can now retry to to write utf8 character into your database. This solution help me when i try to upload 200000 row of csv file into my database.

Count unique values in a column in Excel

Another tricky way that just occurred to me (tested and it worked!).

  • Select the data in the column
  • In the menu, select Conditional Formatting, Highlight Cells, Duplicate Values
  • Select whether you want to highlight unique or duplicate values.
  • Save the highlight
  • Select the data
  • Go to Data and then Filter

Filter based on color:

Excel -- 2013 at least -- lets you filter on color. Sweet!

Admittedly, this is more for one-off checks of data than a spreadsheet you'll use often, since it requires some formatting changes.

Spring Boot Remove Whitelabel Error Page

Spring boot doc 'was' wrong (they have since fixed it) :

To switch it off you can set error.whitelabel.enabled=false

should be

To switch it off you can set server.error.whitelabel.enabled=false

Render HTML to an image

I know this is quite an old question which already has a lot of answers, yet I still spent hours trying to actually do what I wanted:

  • given an html file, generate a (png) image with transparent background from the command line

Using Chrome headless (version 74.0.3729.157 as of this response), it is actually easy:

"/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" --headless --screenshot --window-size=256,256 --default-background-color=0 button.html

Explanation of the command:

  • you run Chrome from the command line (here shown for the Mac, but assuming similar on Windows or Linux)
  • --headless runs Chrome without opening it and exits after the command completes
  • --screenshot will capture a screenshot (note that it generates a file called screenshot.png in the folder where the command is run)
  • --window-size allow to only capture a portion of the screen (format is --window-size=width,height)
  • --default-background-color=0 is the magic trick that tells Chrome to use a transparent background, not the default white color
  • finally you provide the html file (as a url either local or remote...)

How do I spool to a CSV formatted file using SQLPLUS?

It's crude, but:

set pagesize 0 linesize 500 trimspool on feedback off echo off

select '"' || empno || '","' || ename || '","' || deptno || '"' as text
from emp

spool emp.csv
/
spool off

Scanf/Printf double variable C

When a float is passed to printf, it is automatically converted to a double. This is part of the default argument promotions, which apply to functions that have a variable parameter list (containing ...), largely for historical reasons. Therefore, the “natural” specifier for a float, %f, must work with a double argument. So the %f and %lf specifiers for printf are the same; they both take a double value.

When scanf is called, pointers are passed, not direct values. A pointer to float is not converted to a pointer to double (this could not work since the pointed-to object cannot change when you change the pointer type). So, for scanf, the argument for %f must be a pointer to float, and the argument for %lf must be a pointer to double.

C++ pointer to objects

if you want to access a method :

1) while using an object of a class:

Myclass myclass;
myclass.DoSomething();

2) while using a pointer to an object of a class:

Myclass *myclass=&abc;
myclass->DoSomething();

Maintain model of scope when changing between views in AngularJS

I took a bit of time to work out what is the best way of doing this. I also wanted to keep the state, when the user leaves the page and then presses the back button, to get back to the old page; and not just put all my data into the rootscope.

The final result is to have a service for each controller. In the controller, you just have functions and variables that you dont care about, if they are cleared.

The service for the controller is injected by dependency injection. As services are singletons, their data is not destroyed like the data in the controller.

In the service, I have a model. the model ONLY has data - no functions -. That way it can be converted back and forth from JSON to persist it. I used the html5 localstorage for persistence.

Lastly i used window.onbeforeunload and $rootScope.$broadcast('saveState'); to let all the services know that they should save their state, and $rootScope.$broadcast('restoreState') to let them know to restore their state ( used for when the user leaves the page and presses the back button to return to the page respectively).

Example service called userService for my userController :

app.factory('userService', ['$rootScope', function ($rootScope) {

    var service = {

        model: {
            name: '',
            email: ''
        },

        SaveState: function () {
            sessionStorage.userService = angular.toJson(service.model);
        },

        RestoreState: function () {
            service.model = angular.fromJson(sessionStorage.userService);
        }
    }

    $rootScope.$on("savestate", service.SaveState);
    $rootScope.$on("restorestate", service.RestoreState);

    return service;
}]);

userController example

function userCtrl($scope, userService) {
    $scope.user = userService;
}

The view then uses binding like this

<h1>{{user.model.name}}</h1>

And in the app module, within the run function i handle the broadcasting of the saveState and restoreState

$rootScope.$on("$routeChangeStart", function (event, next, current) {
    if (sessionStorage.restorestate == "true") {
        $rootScope.$broadcast('restorestate'); //let everything know we need to restore state
        sessionStorage.restorestate = false;
    }
});

//let everthing know that we need to save state now.
window.onbeforeunload = function (event) {
    $rootScope.$broadcast('savestate');
};

As i mentioned this took a while to come to this point. It is a very clean way of doing it, but it is a fair bit of engineering to do something that i would suspect is a very common issue when developing in Angular.

I would love to see easier, but as clean ways to handle keeping state across controllers, including when the user leaves and returns to the page.

How do you clear the SQL Server transaction log?

To my experience on most SQL Servers there is no backup of the transaction log. Full backups or differential backups are common practice, but transaction log backups are really seldom. So the transaction log file grows forever (until the disk is full). In this case the recovery model should be set to "simple". Don't forget to modify the system databases "model" and "tempdb", too.

A backup of the database "tempdb" makes no sense, so the recovery model of this db should always be "simple".

Pythonic way to return list of every nth item in a larger list

From manual: s[i:j:k] slice of s from i to j with step k

li = range(100)
sub = li[0::10]

>>> sub
[0, 10, 20, 30, 40, 50, 60, 70, 80, 90]

What is a simple C or C++ TCP server and client example?

If the code should be simple, then you probably asking for C example based on traditional BSD sockets. Solutions like boost::asio are imho quite complicated when it comes to short and simple "hello world" example.

To compile examples you mentioned you must make simple fixes, because you are compiling under C++ compiler. I'm referring to following files:
http://www.linuxhowtos.org/data/6/server.c
http://www.linuxhowtos.org/data/6/client.c
from: http://www.linuxhowtos.org/C_C++/socket.htm

  1. Add following includes to both files:

    #include <cstdlib>
    #include <cstring>
    #include <unistd.h>
    
  2. In client.c, change the line:

    if (connect(sockfd,&serv_addr,sizeof(serv_addr)) < 0)
    { ... }
    

    to:

    if (connect(sockfd,(const sockaddr*)&serv_addr,sizeof(serv_addr)) < 0)
    { ... }
    

As you can see in C++ an explicit cast is needed.

python: [Errno 10054] An existing connection was forcibly closed by the remote host

I know this is a very old question but it may be that you need to set the request headers. This solved it for me.

For example 'user-agent', 'accept' etc. here is an example with user-agent:

url = 'your-url-here'
headers = {'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.75 Safari/537.36'}
r = requests.get(url, headers=headers)

How to reverse apply a stash?

According to the git-stash manpage, "A stash is represented as a commit whose tree records the state of the working directory, and its first parent is the commit at HEAD when the stash was created," and git stash show -p gives us "the changes recorded in the stash as a diff between the stashed state and its original parent.

To keep your other changes intact, use git stash show -p | patch --reverse as in the following:

$ git init
Initialized empty Git repository in /tmp/repo/.git/

$ echo Hello, world >messages

$ git add messages

$ git commit -am 'Initial commit'
[master (root-commit)]: created 1ff2478: "Initial commit"
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 messages

$ echo Hello again >>messages

$ git stash

$ git status
# On branch master
nothing to commit (working directory clean)

$ git stash apply
# On branch master
# Changed but not updated:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#       modified:   messages
#
no changes added to commit (use "git add" and/or "git commit -a")

$ echo Howdy all >>messages

$ git diff
diff --git a/messages b/messages
index a5c1966..eade523 100644
--- a/messages
+++ b/messages
@@ -1 +1,3 @@
 Hello, world
+Hello again
+Howdy all

$ git stash show -p | patch --reverse
patching file messages
Hunk #1 succeeded at 1 with fuzz 1.

$ git diff
diff --git a/messages b/messages
index a5c1966..364fc91 100644
--- a/messages
+++ b/messages
@@ -1 +1,2 @@
 Hello, world
+Howdy all

Edit:

A light improvement to this is to use git apply in place of patch:

git stash show -p | git apply --reverse

Alternatively, you can also use git apply -R as a shorthand to git apply --reverse.

I've been finding this really handy lately...

Get driving directions using Google Maps API v2

This is what I am using,

Intent intent = new Intent(android.content.Intent.ACTION_VIEW, 
Uri.parse("http://maps.google.com/maps?saddr="+latitude_cur+","+longitude_cur+"&daddr="+latitude+","+longitude));
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addCategory(Intent.CATEGORY_LAUNCHER );     
intent.setClassName("com.google.android.apps.maps", "com.google.android.maps.MapsActivity");
startActivity(intent);

Display all items in array using jquery

You should use $.map for this:

var array = ["one", "two", "three"];

var el = $.map(array, function(val, i) {
  return "<span>" + val + "</span>";
});

$(".element").html(el.join(""));

jsFiddle demo

laravel compact() and ->with()

You can pass array of variables to the compact as an arguement eg:

return view('yourView', compact(['var1','var2',....'varN']));

in view: if var1 is an object you can use it something like this

@foreach($var1 as $singleVar1)
    {{$singleVar1->property}}
@endforeach

incase of single variable you can simply

{{$var2}}

i have done this several times without any issues

How to swap two variables in JavaScript

We are able to swap var like this :

var val1 =  117,
    val2 = 327;

val2 = val1-val2; 
console.log(val2);
val1 = val1-val2;
console.log(val1);
val2 = val1+val2;
console.log(val2);

Css Move element from left to right animated

You should try doing it with css3 animation. Check the code bellow:

<!DOCTYPE html>
<html>
<head>
<style> 
div {
    width: 100px;
    height: 100px;
    background: red;
    position: relative;
    -webkit-animation: myfirst 5s infinite; /* Chrome, Safari, Opera */
    -webkit-animation-direction: alternate; /* Chrome, Safari, Opera */
    animation: myfirst 5s infinite;
    animation-direction: alternate;
}

/* Chrome, Safari, Opera */
@-webkit-keyframes myfirst {
    0%   {background: red; left: 0px; top: 0px;}
    25%  {background: yellow; left: 200px; top: 0px;}
    50%  {background: blue; left: 200px; top: 200px;}
    75%  {background: green; left: 0px; top: 200px;}
    100% {background: red; left: 0px; top: 0px;}
}

@keyframes myfirst {
    0%   {background: red; left: 0px; top: 0px;}
    25%  {background: yellow; left: 200px; top: 0px;}
    50%  {background: blue; left: 200px; top: 200px;}
    75%  {background: green; left: 0px; top: 200px;}
    100% {background: red; left: 0px; top: 0px;}
}
</style>
</head>
<body>

<p><strong>Note:</strong> The animation-direction property is not supported in Internet Explorer 9 and earlier versions.</p>
<div></div>

</body>
</html>

Where 'div' is your animated object.

I hope you find this useful.

Thanks.

What command means "do nothing" in a conditional in Bash?

Although I'm not answering the original question concering the no-op command, many (if not most) problems when one may think "in this branch I have to do nothing" can be bypassed by simply restructuring the logic so that this branch won't occur.

I try to give a general rule by using the OPs example

do nothing when $a is greater than "10", print "1" if $a is less than "5", otherwise, print "2"

we have to avoid a branch where $a gets more than 10, so $a < 10 as a general condition can be applied to every other, following condition.

In general terms, when you say do nothing when X, then rephrase it as avoid a branch where X. Usually you can make the avoidance happen by simply negating X and applying it to all other conditions.

So the OPs example with the rule applied may be restructured as:

if [ "$a" -lt 10 ] && [ "$a" -le 5 ]
then
    echo "1"
elif [ "$a" -lt 10 ]
then
    echo "2"
fi

Just a variation of the above, enclosing everything in the $a < 10 condition:

if [ "$a" -lt 10 ]
then
    if [ "$a" -le 5 ]
    then
        echo "1"
    else
        echo "2"
    fi
fi

(For this specific example @Flimzys restructuring is certainly better, but I wanted to give a general rule for all the people searching how to do nothing.)

How to change a single value in a NumPy array?

Is this what you are after? Just index the element and assign a new value.

A[2,1]=150

A
Out[345]: 
array([[ 1,  2,  3,  4],
       [ 5,  6,  7,  8],
       [ 9, 150, 11, 12],
       [13, 14, 15, 16]])

Formatting Decimal places in R

Looks to me like to would be something like

library(tutoR)
format(1.128347132904321674821, 2)

Per a little online help.

E: Unable to locate package npm

in my jenkins/jenkins docker sudo always generates error:

bash: sudo: command not found

I needed update repo list with:

curl -sL https://deb.nodesource.com/setup_10.x | apt-get update

then,

 apt-get install nodejs

All the command line results like this:

root@76e6f92724d1:/# curl -sL https://deb.nodesource.com/setup_10.x | apt-get update
Ign:1 http://deb.debian.org/debian stretch InRelease
Get:2 http://security.debian.org/debian-security stretch/updates InRelease [94.3 kB]
Get:3 http://deb.debian.org/debian stretch-updates InRelease [91.0 kB]
Get:4 http://deb.debian.org/debian stretch Release [118 kB]
Get:5 http://security.debian.org/debian-security stretch/updates/main amd64 Packages [520 kB]
Get:6 http://deb.debian.org/debian stretch-updates/main amd64 Packages [27.9 kB]
Get:8 http://deb.debian.org/debian stretch Release.gpg [2410 B]
Get:9 http://deb.debian.org/debian stretch/main amd64 Packages [7083 kB]
Get:7 https://packagecloud.io/github/git-lfs/debian stretch InRelease [23.2 kB]
Get:10 https://packagecloud.io/github/git-lfs/debian stretch/main amd64 Packages [4675 B]
Fetched 7965 kB in 20s (393 kB/s)
Reading package lists... Done
root@76e6f92724d1:/#  apt-get install nodejs
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libicu57 libuv1
The following NEW packages will be installed:
  libicu57 libuv1 nodejs
0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
Need to get 11.2 MB of archives.
After this operation, 45.2 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://deb.debian.org/debian stretch/main amd64 libicu57 amd64 57.1-6+deb9u3 [7705 kB]
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Fetched 11.2 MB in 26s (418 kB/s)
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update-alternatives: using /usr/bin/nodejs to provide /usr/bin/js (js) in auto mode

Get multiple elements by Id

Below is the work around to submit Multi values, in case of converting the application from ASP to PHP

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
</HEAD>
<script language="javascript">
function SetValuesOfSameElements() {
    var Arr_Elements = [];
    Arr_Elements = document.getElementsByClassName("MultiElements");

    for(var i=0; i<Arr_Elements.length; i++) {
        Arr_Elements[i].value = '';
        var Element_Name = Arr_Elements[i].name;
        var Main_Element_Type = Arr_Elements[i].getAttribute("MainElementType");
        var Multi_Elements = [];
        Multi_Elements = document.getElementsByName(Element_Name);
        var Multi_Elements_Values = '';
//alert(Element_Name + " > " + Main_Element_Type + " > " + Multi_Elements_Values);
        if (Main_Element_Type == "CheckBox") {
            for(var j=0; j<Multi_Elements.length; j++) {
                if (Multi_Elements[j].checked == true) {
                    if (Multi_Elements_Values == '') {
                        Multi_Elements_Values = Multi_Elements[j].value;
                    }
                    else {
                        Multi_Elements_Values += ', '+ Multi_Elements[j].value;
                    }
                }
            }
        }
        if (Main_Element_Type == "Hidden" || Main_Element_Type == "TextBox") {
            for(var j=0; j<Multi_Elements.length; j++) {
                if (Multi_Elements_Values == '') {
                    Multi_Elements_Values = Multi_Elements[j].value;
                }
                else {
                    if (Multi_Elements[j].value != '') {
                        Multi_Elements_Values += ', '+ Multi_Elements[j].value;
                    }
                }
            }
        }
        Arr_Elements[i].value = Multi_Elements_Values;
    }
}

</script>
<BODY>
<form name="Training" action="TestCB.php" method="get" onsubmit="SetValuesOfSameElements()"/>
    <table>

        <tr>
            <td>Check Box</td>
            <td>
                <input type="CheckBox" name="TestCB" id="TestCB" value="123">123</input>
                <input type="CheckBox" name="TestCB" id="TestCB" value="234">234</input>
                <input type="CheckBox" name="TestCB" id="TestCB" value="345">345</input>
            </td>
            <td>
                <input type="hidden" name="SdPart" id="SdPart" value="1231"></input>
                <input type="hidden" name="SdPart" id="SdPart" value="2341"></input>
                <input type="hidden" name="SdPart" id="SdPart" value="3451"></input>

                <input type="textbox" name="Test11" id="Test11" value="345111"></input>

                <!-- Define hidden Elements with Class name 'MultiElements' for all the Form Elements that used the Same Name (Check Boxes, Multi Select, Text Elements with the Same Name, Hidden Elements with the Same Name, etc 
                -->
                <input type="hidden" MainElementType="CheckBox" name="TestCB" class="MultiElements" value=""></input>
                <input type="hidden" MainElementType="Hidden" name="SdPart" class="MultiElements" value=""></input>
                <input type="hidden" MainElementType="TextBox" name="Test11" class="MultiElements" value=""></input>
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <input type="Submit" name="Submit" id="Submit" value="Submit" />
            </td>
        </tr>
    </table>
</form>

</BODY>
</HTML>


testCB.php 

<?php
echo $_GET["TestCB"];
echo "<br/>";
echo $_GET["SdPart"];
echo "<br/>";
echo $_GET["Test11"];
?>

Django Model() vs Model.objects.create()

The differences between Model() and Model.objects.create() are the following:


  1. INSERT vs UPDATE

    Model.save() does either INSERT or UPDATE of an object in a DB, while Model.objects.create() does only INSERT.

    Model.save() does

    • UPDATE If the object’s primary key attribute is set to a value that evaluates to True

    • INSERT If the object’s primary key attribute is not set or if the UPDATE didn’t update anything (e.g. if primary key is set to a value that doesn’t exist in the database).


  1. Existing primary key

    If primary key attribute is set to a value and such primary key already exists, then Model.save() performs UPDATE, but Model.objects.create() raises IntegrityError.

    Consider the following models.py:

    class Subject(models.Model):
       subject_id = models.PositiveIntegerField(primary_key=True, db_column='subject_id')
       name = models.CharField(max_length=255)
       max_marks = models.PositiveIntegerField()
    
    1. Insert/Update to db with Model.save()

      physics = Subject(subject_id=1, name='Physics', max_marks=100)
      physics.save()
      math = Subject(subject_id=1, name='Math', max_marks=50)  # Case of update
      math.save()
      

      Result:

      Subject.objects.all().values()
      <QuerySet [{'subject_id': 1, 'name': 'Math', 'max_marks': 50}]>
      
    2. Insert to db with Model.objects.create()

      Subject.objects.create(subject_id=1, name='Chemistry', max_marks=100)
      IntegrityError: UNIQUE constraint failed: m****t.subject_id
      

    Explanation: In the example, math.save() does an UPDATE (changes name from Physics to Math, and max_marks from 100 to 50), because subject_id is a primary key and subject_id=1 already exists in the DB. But Subject.objects.create() raises IntegrityError, because, again the primary key subject_id with the value 1 already exists.


  1. Forced insert

    Model.save() can be made to behave as Model.objects.create() by using force_insert=True parameter: Model.save(force_insert=True).


  1. Return value

    Model.save() return None where Model.objects.create() return model instance i.e. package_name.models.Model


Conclusion: Model.objects.create() does model initialization and performs save() with force_insert=True.

Excerpt from the source code of Model.objects.create()

def create(self, **kwargs):
    """
    Create a new object with the given kwargs, saving it to the database
    and returning the created object.
    """
    obj = self.model(**kwargs)
    self._for_write = True
    obj.save(force_insert=True, using=self.db)
    return obj

For more details follow the links:

  1. https://docs.djangoproject.com/en/stable/ref/models/querysets/#create

  2. https://github.com/django/django/blob/2d8dcba03aae200aaa103ec1e69f0a0038ec2f85/django/db/models/query.py#L440

Understanding the Gemfile.lock file

What does the exclamation mark after the gem name in the 'DEPENDECIES' group mean?

The exclamation mark appears when the gem was installed using a source other than "https://rubygems.org".

env: node: No such file or directory in mac

I got such a problem after I upgraded my node version with brew. To fix the problem

1)run $brew doctor to check out if it is successfully installed or not 2) In case you missed clearing any node-related file before, such error log might pop up:

Warning: You have unlinked kegs in your Cellar Leaving kegs unlinked can lead to build-trouble and cause brews that depend on those kegs to fail to run properly once built. node

3) Now you are recommended to run brew link command to delete the original node-related files and overwrite new files - $ brew link node.

And that's it - everything works again !!!

Bootstrap 3: pull-right for col-lg only

It is very simple using Sass, just use @extend:

.pull-right-xs { 
    @extend .pull-right;
 }

Split string into individual words Java

Yet another method, using StringTokenizer :

String s = "I want to walk my dog";
StringTokenizer tokenizer = new StringTokenizer(s);

while(tokenizer.hasMoreTokens()) {
    System.out.println(tokenizer.nextToken());
}

Integer to hex string in C++

I would like to add an answer to enjoy the beauty of C ++ language. Its adaptability to work at high and low levels. Happy programming.

public:template <class T,class U> U* Int2Hex(T lnumber, U* buffer)
{
    const char* ref = "0123456789ABCDEF";
    T hNibbles = (lnumber >> 4);

    unsigned char* b_lNibbles = (unsigned char*)&lnumber;
    unsigned char* b_hNibbles = (unsigned char*)&hNibbles;

    U* pointer = buffer + (sizeof(lnumber) << 1);

    *pointer = 0;
    do {
        *--pointer = ref[(*b_lNibbles++) & 0xF];
        *--pointer = ref[(*b_hNibbles++) & 0xF];
    } while (pointer > buffer);

    return buffer;
}

Examples:

char buffer[100] = { 0 };
Int2Hex(305419896ULL, buffer);//returns "0000000012345678"
Int2Hex(305419896UL, buffer);//returns "12345678"
Int2Hex((short)65533, buffer);//returns "FFFD"
Int2Hex((char)18, buffer);//returns "12"

wchar_t buffer[100] = { 0 };
Int2Hex(305419896ULL, buffer);//returns L"0000000012345678"
Int2Hex(305419896UL, buffer);//returns L"12345678"
Int2Hex((short)65533, buffer);//returns L"FFFD"
Int2Hex((char)18, buffer);//returns L"12"

Does GPS require Internet?

GPS does not need any kind of internet or wireless connection, but there are technologies like A-GPS that use the mobile network to shorten the time to first fix, or the initial positioning or increase the precision in situations when there is a low satellite visibility.

Android phones tend to use A-GPS. If there is no connectivity, they use pure GPS. They do not override the data network mode. If you deactivated it, the phone won't use any data connection (which is handy if you are abroad, and do not want to pay expensive data roaming).

Cleanest way to build an SQL string in Java

I am wondering if you are after something like Squiggle. Also something very useful is jDBI. It won't help you with the queries though.

How to change a TextView's style at runtime

Like Jonathan suggested, using textView.setTextTypeface works, I just used it in an app a few seconds ago.

textView.setTypeface(null, Typeface.BOLD); // Typeface.NORMAL, Typeface.ITALIC etc.

ngFor with index as value in attribute

Adding this late answer to show a case most people will come across. If you only need to see what is the last item in the list, use the last key word:

<div *ngFor="let item of devcaseFeedback.reviewItems; let last = last">
  <divider *ngIf="!last"></divider>
</div>

This will add the divider component to every item except the last.

Because of the comment below, I will add the rest of the ngFor exported values that can be aliased to local variables (As are shown in the docs):

  • $implicit: T: The value of the individual items in the iterable (ngForOf).
  • ngForOf: NgIterable: The value of the iterable expression. Useful when the expression is more complex then a property access, for example when using the async pipe (userStreams | async).
  • index: number: The index of the current item in the iterable.
  • count: number: The length of the iterable.
  • count: number: The length of the iterable.
  • first: boolean: True when the item is the first item in the iterable.
  • last: boolean: True when the item is the last item in the iterable.
  • even: boolean: True when the item has an even index in the iterable.
  • odd: boolean: True when the item has an odd index in the iterable.

COALESCE Function in TSQL

There is a lot more to coalesce than just a replacement for ISNULL. I completely agree that the official "documentation" of coalesce is vague and unhelpful. This article helps a lot. http://www.mssqltips.com/sqlservertip/1521/the-many-uses-of-coalesce-in-sql-server/

Removing border from table cells

You might want to try this: http://jsfiddle.net/QPKVX/

Not really sure what you want your final layout to look like- but that fixes the colspan problem too.

How to POST raw whole JSON in the body of a Retrofit request?

While creating OkHttpClient that will be used for Retrofit.

add an Interceptor like this.

 private val httpClient = OkHttpClient.Builder()
        .addInterceptor (other interceptors)
        ........................................

        //This Interceptor is the main logging Interceptor
        .addInterceptor { chain ->
            val request = chain.request()
            val jsonObj = JSONObject(Gson().toJson(request))

            val requestBody = (jsonObj
            ?.getJSONObject("tags")
            ?.getJSONObject("class retrofit2.Invocation")
            ?.getJSONArray("arguments")?.get(0) ?: "").toString()
            val url = jsonObj?.getJSONObject("url")?.getString("url") ?: ""
            
            Timber.d("gsonrequest request url: $url")
            Timber.d("gsonrequest body :$requestBody")

            chain.proceed(request)
        }
        
        ..............
        // Add other configurations
        .build()

Now your every Retrofit call's URL and request body will be logged in Logcat. Filter it by "gsonrequest"

How to convert decimal to hexadecimal in JavaScript

How to convert decimal to hexadecimal in JavaScript

I wasn't able to find a brutally clean/simple decimal to hexadecimal conversion that didn't involve a mess of functions and arrays ... so I had to make this for myself.

function DecToHex(decimal) { // Data (decimal)

    length = -1;    // Base string length
    string = '';    // Source 'string'

    characters = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' ]; // character array

    do { // Grab each nibble in reverse order because JavaScript has no unsigned left shift

        string += characters[decimal & 0xF];   // Mask byte, get that character
        ++length;                              // Increment to length of string

    } while (decimal >>>= 4); // For next character shift right 4 bits, or break on 0

    decimal += 'x'; // Convert that 0 into a hex prefix string -> '0x'

    do
        decimal += string[length];
    while (length--); // Flip string forwards, with the prefixed '0x'

    return (decimal); // return (hexadecimal);
}

/* Original: */

D = 3678;    // Data (decimal)
C = 0xF;    // Check
A = D;        // Accumulate
B = -1;        // Base string length
S = '';        // Source 'string'
H = '0x';    // Destination 'string'

do {
    ++B;
    A& = C;

    switch(A) {
        case 0xA: A='A'
        break;

        case 0xB: A='B'
        break;

        case 0xC: A='C'
        break;

        case 0xD: A='D'
        break;

        case 0xE: A='E'
        break;

        case 0xF: A='F'
        break;

        A = (A);
    }
    S += A;

    D >>>= 0x04;
    A = D;
} while(D)

do
    H += S[B];
while (B--)

S = B = A = C = D; // Zero out variables
alert(H);    // H: holds hexadecimal equivalent

ListView inside ScrollView is not scrolling on Android

The best solution is to use NestedScrollVew with RecyclerView or if you want to go with Listview then you can add header and footer view to this. For example:

View footerView = ((LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.outofoffice_footer_view, null, false);
infoListView.addFooterView(footerView);

Fluid or fixed grid system, in responsive design, based on Twitter Bootstrap

Interesting discussion. I was asking myself this question too. The main difference between fluid and fixed is simply that the fixed layout has a fixed width in terms of the whole layout of the website (viewport). If you have a 960px width viewport each colum has a fixed width which will never change.

The fluid layout behaves different. Imagine you have set the width of your main layout to 100% width. Now each column will only be calculated to it's relative size (i.e. 25%) and streches as the browser will be resized. So based on your layout purpose you can select how your layout behaves.

Here is a good article about fluid vs. flex.

Laravel 5 Failed opening required bootstrap/../vendor/autoload.php

Just run this inside the directory where you installed your project

composer install

How do I resolve "HTTP Error 500.19 - Internal Server Error" on IIS7.0

Was having the same error and fixing the credentials in the IIS app pool did not help. I finally resolved the error in IIS by selecting my website under Default Web Site, Advanced Settings->Physical Path Credentials->Specific User, and reentered the credentials for the app pool user, then restarted IIS and the error went away and my website came up successfully.

Warning: mysqli_connect(): (HY000/1045): Access denied for user 'username'@'localhost' (using password: YES)

try

define("DB_PASSWORD", null);

and those are warnings try

$db = @mysqli_connect(DB_SERVER,DB_USERNAME,DB_PASSWORD,DB_DATABASE);

But i will recommend you to set a root password

error: the details of the application error from being viewed remotely

Dear olga is clear what the message says. Turn off the custom errors to see the details about this error for fix it, and then you close them back. So add mode="off" as:

<configuration>
    <system.web>
        <customErrors mode="Off"/>
    </system.web>
</configuration>

Relative answer: Deploying website: 500 - Internal server error

By the way: The error message declare that the web.config is not the one you type it here. Maybe you have forget to upload your web.config ? And remember to close the debug flag on the web.config that you use for online pages.

SyntaxError: Non-ASCII character '\xa3' in file when function returns '£'

Adding the following two lines in the script solved the issue for me.

# !/usr/bin/python
# coding=utf-8

Hope it helps !

What is "not assignable to parameter of type never" error in typescript?

I got the same error in ReactJS function component, using ReactJS useState hook. The solution was to declare the type of useState at initialisation:

const [items , setItems] = useState<IItem[]>([]); // replace IItem[] with your own typing: string, boolean...

JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object

Quick fix that worked for me:

for file in $(find "$JAVA_HOME" -name "*pack")
do 
    unpack200 "${file}" "${test_file/%pack/jar}";
done

Programmatically register a broadcast receiver

It is best practice to always supply the permission when registering the receiver, otherwise you will receive for any application that sends a matching intent. This can allow malicious apps to broadcast to your receiver.

jQuery load more data on scroll

If not all of your document scrolls, say, when you have a scrolling div within the document, then the above solutions won't work without adaptations. Here's how to check whether the div's scrollbar has hit the bottom:

$('#someScrollingDiv').on('scroll', function() {
    let div = $(this).get(0);
    if(div.scrollTop + div.clientHeight >= div.scrollHeight) {
        // do the lazy loading here
    }
});

Sending a mail from a linux shell script

You don't even need an MTA. The SMTP protocol is simple enough to directly write it to your SMTP server. You can even communicate over SSL/TLS if you have the OpenSSL package installed. Check this post: https://33hops.com/send-email-from-bash-shell.html

The above is an example on how to send text/html e-mails that will work out of the box. If you want to add attachments the thing can get a bit more complicated, you will need to base64 encode the binary files and embed them between boundaries. THis is a good place to start investigating: http://forums.codeguru.com/showthread.php?418377-Send-Email-w-attachments-using-SMTP

How can I get a collection of keys in a JavaScript dictionary?

For new browsers: Object.keys( MY_DICTIONARY ) will return an array of keys. Else you may want to go the old school way:

var keys = []
for(var key in dic) keys.push( key );

Disable Copy or Paste action for text box?

Check this fiddle.

 $('#email').bind("cut copy paste",function(e) {
     e.preventDefault();
 });

You need to bind what should be done on cut, copy and paste. You prevent default behavior of the action.

You can find a detailed explanation here.

grep regex whitespace behavior

This looks like a behavior difference in the handling of \s between grep 2.5 and newer versions (a bug in old grep?). I confirm your result with grep 2.5.4, but all four of your greps do work when using grep 2.6.3 (Ubuntu 10.10).

Note:

GNU grep 2.5.4
echo "foo bar" | grep "\s"
   (doesn't match)

whereas

GNU grep 2.6.3
echo "foo bar" | grep "\s"
foo bar

Probably less trouble (as \s is not documented):

Both GNU greps
echo "foo bar" | grep "[[:space:]]"
foo bar

My advice is to avoid using \s ... use [ \t]* or [[:space:]] or something like it instead.

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

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

Return an empty Observable

Came here with a similar question, the above didn't work for me in: "rxjs": "^6.0.0", in order to generate an observable that emits no data I needed to do:

import {Observable,empty} from 'rxjs';
class ActivatedRouteStub {
  params: Observable<any> = empty();
}

Convert char array to a int number in C

It isn't that hard to deal with the character array itself without converting the array to a string. Especially in the case where the length of the character array is know or can be easily found. With the character array, the length must be determined in the same scope as the array definition, e.g.:

size_t len sizeof myarray/sizeof *myarray;

For strings you, of course, have strlen available.

With the length known, regardless of whether it is a character array or a string, you can convert the character values to a number with a short function similar to the following:

/* convert character array to integer */
int char2int (char *array, size_t n)
{    
    int number = 0;
    int mult = 1;

    n = (int)n < 0 ? -n : n;       /* quick absolute value check  */

    /* for each character in array */
    while (n--)
    {
        /* if not digit or '-', check if number > 0, break or continue */
        if ((array[n] < '0' || array[n] > '9') && array[n] != '-') {
            if (number)
                break;
            else
                continue;
        }

        if (array[n] == '-') {      /* if '-' if number, negate, break */
            if (number) {
                number = -number;
                break;
            }
        }
        else {                      /* convert digit to numeric value   */
            number += (array[n] - '0') * mult;
            mult *= 10;
        }
    }

    return number;
}

Above is simply the standard char to int conversion approach with a few additional conditionals included. To handle stray characters, in addition to the digits and '-', the only trick is making smart choices about when to start collecting digits and when to stop.

If you start collecting digits for conversion when you encounter the first digit, then the conversion ends when you encounter the first '-' or non-digit. This makes the conversion much more convenient when interested in indexes such as (e.g. file_0127.txt).

A short example of its use:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int char2int (char *array, size_t n);

int main (void) {

    char myarray[4] = {'-','1','2','3'}; 
    char *string = "some-goofy-string-with-123-inside";
    char *fname = "file-0123.txt";

    size_t mlen = sizeof myarray/sizeof *myarray;
    size_t slen = strlen (string);
    size_t flen = strlen (fname);

    printf ("\n myarray[4] = {'-','1','2','3'};\n\n");
    printf ("   char2int (myarray, mlen):  %d\n\n", char2int (myarray, mlen));

    printf (" string = \"some-goofy-string-with-123-inside\";\n\n");
    printf ("   char2int (string, slen) :  %d\n\n", char2int (string, slen));

    printf (" fname = \"file-0123.txt\";\n\n");
    printf ("   char2int (fname, flen)  :  %d\n\n", char2int (fname, flen));

    return 0;
}

Note: when faced with '-' delimited file indexes (or the like), it is up to you to negate the result. (e.g. file-0123.txt compared to file_0123.txt where the first would return -123 while the second 123).

Example Output

$ ./bin/atoic_array

 myarray[4] = {'-','1','2','3'};

   char2int (myarray, mlen):  -123

 string = "some-goofy-string-with-123-inside";

   char2int (string, slen) :  -123

 fname = "file-0123.txt";

   char2int (fname, flen)  :  -123

Note: there are always corner cases, etc. that can cause problems. This isn't intended to be 100% bulletproof in all character sets, etc., but instead work an overwhelming majority of the time and provide additional conversion flexibility without the initial parsing or conversion to string required by atoi or strtol, etc.

Can Python test the membership of multiple values in a list?

Another way to do it:

>>> set(['a','b']).issubset( ['b','a','foo','bar'] )
True

How to "select distinct" across multiple data frame columns in pandas?

To solve a similar problem, I'm using groupby:

print(f"Distinct entries: {len(df.groupby(['col1', 'col2']))}")

Whether that's appropriate will depend on what you want to do with the result, though (in my case, I just wanted the equivalent of COUNT DISTINCT as shown).

Can iterators be reset in Python?

I'm arriving at this same issue - while I like the tee() solution, I don't know how big my files are going to be and the memory warnings about consuming one first before the other are putting me off adopting that method.

Instead, I'm creating a pair of iterators using iter() statements, and using the first for my initial run-through, before switching to the second one for the final run.

So, in the case of a dict-reader, if the reader is defined using:

d = csv.DictReader(f, delimiter=",")

I can create a pair of iterators from this "specification" - using:

d1, d2 = iter(d), iter(d)

I can then run my 1st-pass code against d1, safe in the knowledge that the second iterator d2 has been defined from the same root specification.

I've not tested this exhaustively, but it appears to work with dummy data.

.htaccess - how to force "www." in a generic way?

This will do it:

RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]

PHP, display image with Header()

There is a better why to determine type of an image. with exif_imagetype

If you use this function, you can tell image's real extension.

with this function filename's extension is completely irrelevant, which is good.

function setHeaderContentType(string $filePath): void
{
    $numberToContentTypeMap = [
        '1' => 'image/gif',
        '2' => 'image/jpeg',
        '3' => 'image/png',
        '6' => 'image/bmp',
        '17' => 'image/ico'
    ];

    $contentType = $numberToContentTypeMap[exif_imagetype($filePath)] ?? null;
    
    if ($contentType === null) {
        throw new Exception('Unable to determine content type of file.');
    }

    header("Content-type: $contentType");
}

You can add more types from the link.

Hope it helps.

Adding a UISegmentedControl to UITableView

   self.tableView.tableHeaderView = segmentedControl; 

If you want it to obey your width and height properly though enclose your segmentedControl in a UIView first as the tableView likes to mangle your view a bit to fit the width.

enter image description here enter image description here

Design Documents (High Level and Low Level Design Documents)

High-Level Design (HLD) involves decomposing a system into modules, and representing the interfaces & invocation relationships among modules. An HLD is referred to as software architecture.

LLD, also known as a detailed design, is used to design internals of the individual modules identified during HLD i.e. data structures and algorithms of the modules are designed and documented.

Now, HLD and LLD are actually used in traditional Approach (Function-Oriented Software Design) whereas, in OOAD, the system is seen as a set of objects interacting with each other.

As per the above definitions, a high-level design document will usually include a high-level architecture diagram depicting the components, interfaces, and networks that need to be further specified or developed. The document may also depict or otherwise refer to work flows and/or data flows between component systems.

Class diagrams with all the methods and relations between classes come under LLD. Program specs are covered under LLD. LLD describes each and every module in an elaborate manner so that the programmer can directly code the program based on it. There will be at least 1 document for each module. The LLD will contain - a detailed functional logic of the module in pseudo code - database tables with all elements including their type and size - all interface details with complete API references(both requests and responses) - all dependency issues - error message listings - complete inputs and outputs for a module.

Converting Array to List

If you are dealing with String[] instead of int[], We can use

ArrayList<String> list = new ArrayList<>();
list.addAll(Arrays.asList(StringArray));

Angular 2 change event - model changes

Use the (ngModelChange) event to detect changes on the model

How to use jQuery in AngularJS

Ideally you would put that in a directive, but you can also just put it in the controller. http://jsfiddle.net/tnq86/15/

  angular.module('App', [])
    .controller('AppCtrl', function ($scope) {

      $scope.model = 0;

      $scope.initSlider = function () {
          $(function () {
            // wait till load event fires so all resources are available
              $scope.$slider = $('#slider').slider({
                  slide: $scope.onSlide
              });
          });

          $scope.onSlide = function (e, ui) {
             $scope.model = ui.value;
             $scope.$digest();
          };
      };

      $scope.initSlider();
  });

The directive approach:

HTML

<div slider></div>

JS

  angular.module('App', [])
    .directive('slider', function (DataModel) {
      return {
         restrict: 'A',
         scope: true,
         controller: function ($scope, $element, $attrs) {
            $scope.onSlide = function (e, ui) {
              $scope.model = ui.value;
              // or set it on the model
              // DataModel.model = ui.value;
              // add to angular digest cycle
              $scope.$digest();
            };
         },
         link: function (scope, el, attrs) {

            var options = {
              slide: scope.onSlide  
            };

            // set up slider on load
            angular.element(document).ready(function () {
              scope.$slider = $(el).slider(options);
            });
         }
      }
  });

I would also recommend checking out Angular Bootstrap's source code: https://github.com/angular-ui/bootstrap/blob/master/src/tooltip/tooltip.js

You can also use a factory to create the directive. This gives you ultimate flexibility to integrate services around it and whatever dependencies you need.

How to recognize swipe in all 4 directions

First create a baseViewController and add viewDidLoad this code "swift4":

class BaseViewController: UIViewController {             

     override func viewDidLoad() {
         super.viewDidLoad()
         let swipeRight = UISwipeGestureRecognizer(target: self, action: #selector(swiped))
         swipeRight.direction = UISwipeGestureRecognizerDirection.right
         self.view.addGestureRecognizer(swipeRight)
         let swipeLeft = UISwipeGestureRecognizer(target: self, action: #selector(swiped))
         swipeLeft.direction = UISwipeGestureRecognizerDirection.left
         self.view.addGestureRecognizer(swipeLeft)
     }

     // Example Tabbar 5 pages
     @objc func swiped(_ gesture: UISwipeGestureRecognizer) {
         if gesture.direction == .left {
            if (self.tabBarController?.selectedIndex)! < 5 {
                self.tabBarController?.selectedIndex += 1
            }
         } else if gesture.direction == .right {
             if (self.tabBarController?.selectedIndex)! > 0 {
                 self.tabBarController?.selectedIndex -= 1
             }
         }
     }  
}

And use this baseController class:

class YourViewController: BaseViewController {
    // its done. Swipe successful
    //Now you can use all the Controller you have created without writing any code.    
}

What does \0 stand for?

The null character '\0' (also null terminator), abbreviated NUL, is a control character with the value zero. Its the same in C and objective C

The character has much more significance in C and it serves as a reserved character used to signify the end of a string,often called a null-terminated string

The length of a C string (an array containing the characters and terminated with a '\0' character) is found by searching for the (first) NUL byte.

Static variables in C++

Static variable in a header file:

say 'common.h' has

static int zzz;

This variable 'zzz' has internal linkage (This same variable can not be accessed in other translation units). Each translation unit which includes 'common.h' has it's own unique object of name 'zzz'.

Static variable in a class:

Static variable in a class is not a part of the subobject of the class. There is only one copy of a static data member shared by all the objects of the class.

$9.4.2/6 - "Static data members of a class in namespace scope have external linkage (3.5).A local class shall not have static data members."

So let's say 'myclass.h' has

struct myclass{
   static int zzz;        // this is only a declaration
};

and myclass.cpp has

#include "myclass.h"

int myclass::zzz = 0           // this is a definition, 
                               // should be done once and only once

and "hisclass.cpp" has

#include "myclass.h"

void f(){myclass::zzz = 2;}    // myclass::zzz is always the same in any 
                               // translation unit

and "ourclass.cpp" has

#include "myclass.h"
void g(){myclass::zzz = 2;}    // myclass::zzz is always the same in any 
                               // translation unit

So, class static members are not limited to only 2 translation units. They need to be defined only once in any one of the translation units.

Note: usage of 'static' to declare file scope variable is deprecated and unnamed namespace is a superior alternate

Adding Multiple Values in ArrayList at a single index

@Ahamed has a point, but if you're insisting on using lists so you can have three arraylist like this:

ArrayList<Integer> first = new ArrayList<Integer>(Arrays.AsList(100,100,100,100,100));
ArrayList<Integer> second = new ArrayList<Integer>(Arrays.AsList(50,35,25,45,65));
ArrayList<Integer> third = new ArrayList<Integer>();

for(int i = 0; i < first.size(); i++) {
      third.add(first.get(i));
      third.add(second.get(i));
}

Edit: If you have those values on your list that below:

List<double[]> values = new ArrayList<double[]>(2);

what you want to do is combine them, right? You can try something like this: (I assume that both array are same sized, otherwise you need to use two for statement)

ArrayList<Double> yourArray = new ArrayList<Double>();
for(int i = 0; i < values.get(0).length; i++) {
    yourArray.add(values.get(0)[i]);
    yourArray.add(values.get(1)[i]);
}

HTML: How to create a DIV with only vertical scroll-bars for long paragraphs?

overflow-y : scroll;
overflow-x : hidden;

height is optional

Default FirebaseApp is not initialized

My problem was not resolved with this procedure

FirebaseApp.initializeApp(this); 

So I tried something else and now my firebase has been successfully initialized. Try adding following in app module.gradle

BuildScript{
dependencies {..
classpath : "com.google.firebase:firebase-plugins:1.1.5"
    ..}
}

dependencies {...
implementation : "com.google.firebase:firebase-perf:16.1.0"
implementation : "com.google.firebase:firebase-core:16.0.3"
..}

How to display a list inline using Twitter's Bootstrap

Bootstrap 2.3.2

<ul class="inline">
  <li>...</li>
</ul>

Bootstrap 3

<ul class="list-inline">
  <li>...</li>
</ul>

Bootstrap 4

<ul class="list-inline">
  <li class="list-inline-item">Lorem ipsum</li>
  <li class="list-inline-item">Phasellus iaculis</li>
  <li class="list-inline-item">Nulla volutpat</li>
</ul>

source: http://v4-alpha.getbootstrap.com/content/typography/#inline

Updated link https://getbootstrap.com/docs/4.4/content/typography/#inline

Why shouldn't I use "Hungarian Notation"?

As a Python programmer, Hungarian Notation falls apart pretty fast. In Python, I don't care if something is a string - I care if it can act like a string (i.e. if it has a ___str___() method which returns a string).

For example, let's say we have foo as an integer, 12

foo = 12

Hungarian notation tells us that we should call that iFoo or something, to denote it's an integer, so that later on, we know what it is. Except in Python, that doesn't work, or rather, it doesn't make sense. In Python, I decide what type I want when I use it. Do I want a string? well if I do something like this:

print "The current value of foo is %s" % foo

Note the %s - string. Foo isn't a string, but the % operator will call foo.___str___() and use the result (assuming it exists). foo is still an integer, but we treat it as a string if we want a string. If we want a float, then we treat it as a float. In dynamically typed languages like Python, Hungarian Notation is pointless, because it doesn't matter what type something is until you use it, and if you need a specific type, then just make sure to cast it to that type (e.g. float(foo)) when you use it.

Note that dynamic languages like PHP don't have this benefit - PHP tries to do 'the right thing' in the background based on an obscure set of rules that almost no one has memorized, which often results in catastrophic messes unexpectedly. In this case, some sort of naming mechanism, like $files_count or $file_name, can be handy.

In my view, Hungarian Notation is like leeches. Maybe in the past they were useful, or at least they seemed useful, but nowadays it's just a lot of extra typing for not a lot of benefit.

Select all columns except one in MySQL?

I agree with @Mahomedalid's answer, but I didn't want to do something like a prepared statement and I didn't want to type all the fields, so what I had was a silly solution.

Go to the table in phpmyadmin->sql->select, it dumps the query: copy, replace and done! :)

Minimal web server using netcat

LOL, a super lame hack, but at least curl and firefox accepts it:

while true ; do (dd if=/dev/zero count=10000;echo -e "HTTP/1.1\n\n $(date)") | nc -l  1500  ; done

You better replace it soon with something proper!

Ah yes, my nc were not exactly the same as yours, it did not like the -p option.

Illegal string offset Warning PHP

TL;DR

You're trying to access a string as if it were an array, with a key that's a string. string will not understand that. In code we can see the problem:

"hello"["hello"];
// PHP Warning:  Illegal string offset 'hello' in php shell code on line 1

"hello"[0];
// No errors.

array("hello" => "val")["hello"];
// No errors. This is *probably* what you wanted.

In depth

Let's see that error:

Warning: Illegal string offset 'port' in ...

What does it say? It says we're trying to use the string 'port' as an offset for a string. Like this:

$a_string = "string";

// This is ok:
echo $a_string[0]; // s
echo $a_string[1]; // t
echo $a_string[2]; // r
// ...

// !! Not good:
echo $a_string['port'];
// !! Warning: Illegal string offset 'port' in ...

What causes this?

For some reason you expected an array, but you have a string. Just a mix-up. Maybe your variable was changed, maybe it never was an array, it's really not important.

What can be done?

If we know we should have an array, we should do some basic debugging to determine why we don't have an array. If we don't know if we'll have an array or string, things become a bit trickier.

What we can do is all sorts of checking to ensure we don't have notices, warnings or errors with things like is_array and isset or array_key_exists:

$a_string = "string";
$an_array = array('port' => 'the_port');

if (is_array($a_string) && isset($a_string['port'])) {
    // No problem, we'll never get here.
    echo $a_string['port'];
}

if (is_array($an_array) && isset($an_array['port'])) {
    // Ok!
    echo $an_array['port']; // the_port
}

if (is_array($an_array) && isset($an_array['unset_key'])) {
    // No problem again, we won't enter.
    echo $an_array['unset_key'];
}


// Similar, but with array_key_exists
if (is_array($an_array) && array_key_exists('port', $an_array)) {
    // Ok!
    echo $an_array['port']; // the_port
}

There are some subtle differences between isset and array_key_exists. For example, if the value of $array['key'] is null, isset returns false. array_key_exists will just check that, well, the key exists.

Best way to save a trained model in PyTorch?

The pickle Python library implements binary protocols for serializing and de-serializing a Python object.

When you import torch (or when you use PyTorch) it will import pickle for you and you don't need to call pickle.dump() and pickle.load() directly, which are the methods to save and to load the object.

In fact, torch.save() and torch.load() will wrap pickle.dump() and pickle.load() for you.

A state_dict the other answer mentioned deserves just few more notes.

What state_dict do we have inside PyTorch? There are actually two state_dicts.

The PyTorch model is torch.nn.Module has model.parameters() call to get learnable parameters (w and b). These learnable parameters, once randomly set, will update over time as we learn. Learnable parameters are the first state_dict.

The second state_dict is the optimizer state dict. You recall that the optimizer is used to improve our learnable parameters. But the optimizer state_dict is fixed. Nothing to learn in there.

Because state_dict objects are Python dictionaries, they can be easily saved, updated, altered, and restored, adding a great deal of modularity to PyTorch models and optimizers.

Let's create a super simple model to explain this:

import torch
import torch.optim as optim

model = torch.nn.Linear(5, 2)

# Initialize optimizer
optimizer = optim.SGD(model.parameters(), lr=0.001, momentum=0.9)

print("Model's state_dict:")
for param_tensor in model.state_dict():
    print(param_tensor, "\t", model.state_dict()[param_tensor].size())

print("Model weight:")    
print(model.weight)

print("Model bias:")    
print(model.bias)

print("---")
print("Optimizer's state_dict:")
for var_name in optimizer.state_dict():
    print(var_name, "\t", optimizer.state_dict()[var_name])

This code will output the following:

Model's state_dict:
weight   torch.Size([2, 5])
bias     torch.Size([2])
Model weight:
Parameter containing:
tensor([[ 0.1328,  0.1360,  0.1553, -0.1838, -0.0316],
        [ 0.0479,  0.1760,  0.1712,  0.2244,  0.1408]], requires_grad=True)
Model bias:
Parameter containing:
tensor([ 0.4112, -0.0733], requires_grad=True)
---
Optimizer's state_dict:
state    {}
param_groups     [{'lr': 0.001, 'momentum': 0.9, 'dampening': 0, 'weight_decay': 0, 'nesterov': False, 'params': [140695321443856, 140695321443928]}]

Note this is a minimal model. You may try to add stack of sequential

model = torch.nn.Sequential(
          torch.nn.Linear(D_in, H),
          torch.nn.Conv2d(A, B, C)
          torch.nn.Linear(H, D_out),
        )

Note that only layers with learnable parameters (convolutional layers, linear layers, etc.) and registered buffers (batchnorm layers) have entries in the model's state_dict.

Non learnable things, belong to the optimizer object state_dict, which contains information about the optimizer's state, as well as the hyperparameters used.

The rest of the story is the same; in the inference phase (this is a phase when we use the model after training) for predicting; we do predict based on the parameters we learned. So for the inference, we just need to save the parameters model.state_dict().

torch.save(model.state_dict(), filepath)

And to use later model.load_state_dict(torch.load(filepath)) model.eval()

Note: Don't forget the last line model.eval() this is crucial after loading the model.

Also don't try to save torch.save(model.parameters(), filepath). The model.parameters() is just the generator object.

On the other side, torch.save(model, filepath) saves the model object itself, but keep in mind the model doesn't have the optimizer's state_dict. Check the other excellent answer by @Jadiel de Armas to save the optimizer's state dict.

Using Mockito's generic "any()" method

Since Java 8 you can use the argument-less any method and the type argument will get inferred by the compiler:

verify(bar).doStuff(any());

Explanation

The new thing in Java 8 is that the target type of an expression will be used to infer type parameters of its sub-expressions. Before Java 8 only arguments to methods where used for type parameter inference (most of the time).

In this case the parameter type of doStuff will be the target type for any(), and the return value type of any() will get chosen to match that argument type.

This mechanism was added in Java 8 mainly to be able to compile lambda expressions, but it improves type inferences generally.


Primitive types

This doesn't work with primitive types, unfortunately:

public interface IBar {
    void doPrimitiveStuff(int i);
}

verify(bar).doPrimitiveStuff(any()); // Compiles but throws NullPointerException
verify(bar).doPrimitiveStuff(anyInt()); // This is what you have to do instead

The problem is that the compiler will infer Integer as the return value type of any(). Mockito will not be aware of this (due to type erasure) and return the default value for reference types, which is null. The runtime will try to unbox the return value by calling the intValue method on it before passing it to doStuff, and the exception gets thrown.

Difference between View and table in sql

Table: Table is a preliminary storage for storing data and information in RDBMS. A table is a collection of related data entries and it consists of columns and rows.

View: A view is a virtual table whose contents are defined by a query. Unless indexed, a view does not exist as a stored set of data values in a database. Advantages over table are

  • We can combine columns/rows from multiple table or another view and have a consolidated view.
  • Views can be used as security mechanisms by letting users access data through the view, without granting the users permissions to directly access the underlying base tables of the view
  • It acts as abstract layer to downstream systems, so any change in schema is not exposed and hence the downstream systems doesn't get affected.

Can I set a TTL for @Cacheable

I use life hacking like this

@Configuration
@EnableCaching
@EnableScheduling
public class CachingConfig {
    public static final String GAMES = "GAMES";
    @Bean
    public CacheManager cacheManager() {
        ConcurrentMapCacheManager cacheManager = new ConcurrentMapCacheManager(GAMES);

        return cacheManager;
    }

@CacheEvict(allEntries = true, value = {GAMES})
@Scheduled(fixedDelay = 10 * 60 * 1000 ,  initialDelay = 500)
public void reportCacheEvict() {
    System.out.println("Flush Cache " + dateFormat.format(new Date()));
}

What is inf and nan?

Inf is infinity, it's a "bigger than all the other numbers" number. Try subtracting anything you want from it, it doesn't get any smaller. All numbers are < Inf. -Inf is similar, but smaller than everything.

NaN means not-a-number. If you try to do a computation that just doesn't make sense, you get NaN. Inf - Inf is one such computation. Usually NaN is used to just mean that some data is missing.

How to make a phone call using intent in Android?

IMPORTANT NOTE:

If you use Intent.ACTION_CALL you must add CALL_PHONE permission.

Its okey only if you don't want your app to show up in google play for tablets that doesn't take SIM card or doesn't have GSM.

IN YOUR ACTIVITY:

            Intent callIntent = new Intent(Intent.ACTION_CALL);
            callIntent.setData(Uri.parse("tel:" + Constants.CALL_CENTER_NUMBER));
            startActivity(callIntent);

MANIFEST:

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

So if it is not critical feature to your app, try to stay away from adding CALL_PHONE permission.

OTHER SOLUTION:

Is to show the Phone app with the number written in on the screen, so user will only need to click call button:

            Intent dialIntent = new Intent(Intent.ACTION_DIAL);
            dialIntent.setData(Uri.parse("tel:" + Constants.CALL_CENTER_NUMBER));
            startActivity(dialIntent);

No permission needed for this.

How can I match on an attribute that contains a certain string?

EDIT: see bobince's solution which uses contains rather than start-with, along with a trick to ensure the comparison is done at the level of a complete token (lest the 'atag' pattern be found as part of another 'tag').

"atag btag" is an odd value for the class attribute, but never the less, try:

//*[starts-with(@class,"atag")]

VarBinary vs Image SQL Server Data Type to Store Binary Data?

https://docs.microsoft.com/en-us/sql/t-sql/data-types/ntext-text-and-image-transact-sql

image

Variable-length binary data from 0 through 2^31-1 (2,147,483,647) bytes. Still it IS supported to use image datatype, but be aware of:

https://docs.microsoft.com/en-us/sql/t-sql/data-types/binary-and-varbinary-transact-sql

varbinary [ ( n | max) ]

Variable-length binary data. n can be a value from 1 through 8,000. max indicates that the maximum storage size is 2^31-1 bytes. The storage size is the actual length of the data entered + 2 bytes. The data that is entered can be 0 bytes in length. The ANSI SQL synonym for varbinary is binary varying.

So both are equally in size (2GB). But be aware of:

https://docs.microsoft.com/en-us/sql/database-engine/deprecated-database-engine-features-in-sql-server-2016#features-not-supported-in-a-future-version-of-sql-server

Though the end of "image" datatype is still not determined, you should use the "future" proof equivalent.

But you have to ask yourself: why storing BLOBS in a Column?

https://docs.microsoft.com/en-us/sql/relational-databases/blob/compare-options-for-storing-blobs-sql-server

500 internal server error at GetResponse()

For me this error occurred because I had 2 web API actions that had the exact same signatures and both had the same verbs, HttpPost, what I did was change one of the verbs (the one used for updating) to PUT and the error was removed. The following in my catch statement helped in getting to the root of the problem:

catch (WebException webex)
{
                WebResponse errResp = webex.Response;
                using (Stream respStream = errResp.GetResponseStream())
                {
                    StreamReader reader = new StreamReader(respStream);
                    string text = reader.ReadToEnd();
                }
}

How to prevent downloading images and video files from my website?

I'd like to add a more philosophical comment. The whole intent of the internet, particularly the World Wide Web, is to share data. If you don't want people to download a picture/video/document, don't put it on the web. It's really that simple. Too many people think they can impose their own rules on an existing design. Those who want to post content on the web, and control its distribution, are looking to have their cake and eat it too.

C# windows application Event: CLR20r3 on application start

.NET has two CLRs 2.0 and 4.0. CLR 2.0 works till .NET framework 3.5. CLR 4.0 works from .NET 4.0 onwards. Its possible that your solution is using a different CLR than your reference assemblies. In your local development environment, you might have both the CLRs and hence you did not faced any problem. However when you moved to deployment environments, they might have a single CLR only and you got this error.

How to find the sum of an array of numbers

Funny approach:

eval([1,2,3].join("+"))

How can I use delay() with show() and hide() in Jquery

Pass a duration to show() and hide():

When a duration is provided, .show() becomes an animation method.

E.g. element.delay(1000).show(0)

DEMO

Loop through childNodes

Here is a functional ES6 way of iterating over a NodeList. This method uses the Array's forEach like so:

Array.prototype.forEach.call(element.childNodes, f)

Where f is the iterator function that receives a child nodes as it's first parameter and the index as the second.

If you need to iterate over NodeLists more than once you could create a small functional utility method out of this:

const forEach = f => x => Array.prototype.forEach.call(x, f);

// For example, to log all child nodes
forEach((item) => { console.log(item); })(element.childNodes)

// The functional forEach is handy as you can easily created curried functions
const logChildren = forEach((childNode) => { console.log(childNode); })
logChildren(elementA.childNodes)
logChildren(elementB.childNodes)

(You can do the same trick for map() and other Array functions.)

How to generate an openSSL key using a passphrase from the command line?

genrsa has been replaced by genpkey & when run manually in a terminal it will prompt for a password:

openssl genpkey -aes-256-cbc -algorithm RSA -out /etc/ssl/private/key.pem -pkeyopt rsa_keygen_bits:4096

However when run from a script the command will not ask for a password so to avoid the password being viewable as a process use a function in a shell script:

get_passwd() {
    local passwd=
    echo -ne "Enter passwd for private key: ? "; read -s passwd
    openssl genpkey -aes-256-cbc -pass pass:$passwd -algorithm RSA -out $PRIV_KEY -pkeyopt rsa_keygen_bits:$PRIV_KEYSIZE
}

define a List like List<int,string>?

Since your example uses a generic List, I assume you don't need an index or unique constraint on your data. A List may contain duplicate values. If you want to insure a unique key, consider using a Dictionary<TKey, TValue>().

var list = new List<Tuple<int,string>>();

list.Add(Tuple.Create(1, "Andy"));
list.Add(Tuple.Create(1, "John"));
list.Add(Tuple.Create(3, "Sally"));

foreach (var item in list)
{
    Console.WriteLine(item.Item1.ToString());
    Console.WriteLine(item.Item2);
}

Split a string by a delimiter in python

You may be interested in the csv module, which is designed for comma-separated files but can be easily modified to use a custom delimiter.

import csv
csv.register_dialect( "myDialect", delimiter = "__", <other-options> )
lines = [ "MATCHES__STRING" ]

for row in csv.reader( lines ):
    ...

Expected initializer before function name

Try adding a semi colon to the end of your structure:

 struct sotrudnik {
    string name;
    string speciality;
    string razread;
    int zarplata;
} //Semi colon here

java: run a function after a specific number of seconds

you could use the Thread.Sleep() function

Thread.sleep(4000);
myfunction();

Your function will execute after 4 seconds. However this might pause the entire program...

apache redirect from non www to www

Using the rewrite engine is a pretty heavyweight way to solve this problem. Here is a simpler solution:

<VirtualHost *:80>
    ServerName example.com
    Redirect permanent / http://www.example.com/
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example.com
    # real server configuration
</VirtualHost>

And then you'll have another <VirtualHost> section with ServerName www.example.com for your real server configuration. Apache automatically preserves anything after the / when using the Redirect directive, which is a common misconception about why this method won't work (when in fact it does).

How do you specify a debugger program in Code::Blocks 12.11?

  1. Go to settings >> Debugger.
  2. Now as you can see in the image below. There's a tree. Common->GDB/CDB Debugger -> Default. enter image description here

  3. Click on executable path (on the right) to find the address to gdb32.exe .

  4. Click gdb32.exe >> OK.

THATS IT!! This worked for me.

How to Select a substring in Oracle SQL up to a specific character?

This can be done using REGEXP_SUBSTR easily.

Please use

REGEXP_SUBSTR('STRING_EXAMPLE','[^_]+',1,1) 

where STRING_EXAMPLE is your string.

Try:

SELECT 
REGEXP_SUBSTR('STRING_EXAMPLE','[^_]+',1,1) 
from dual

It will solve your problem.

Date Comparison using Java

Date long getTime() returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Date object.

//test if date1 is before date2
if(date1.getTime() < date2.getTime()) {
....
}

Getting coordinates of marker in Google Maps API

var lat = homeMarker.getPosition().lat();
var lng = homeMarker.getPosition().lng();

See the google.maps.LatLng docs and google.maps.Marker getPosition().

Sys is undefined

I solved this problem by creating separate asp.net ajax solution and copy and paste all ajax configuration from web.config to working project.

here are the must configuration you should set in web.config

    <configuration>
<configSections>
    <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
        <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
            <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
</sectionGroup>

    </sectionGroup>
</configSections>

        <assemblies>

            <add assembly="System.Web.Extensions,     Version=1.0.61025.0,       Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

        </assemblies>
           </compilation>
        <httpHandlers>
        <remove verb="*" path="*.asmx"/>
        <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
    </httpHandlers>
    <httpModules>
        <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </httpModules>
</system.web>
    <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules>
        <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </modules>
    <handlers>
        <remove name="WebServiceHandlerFactory-Integrated"/>
        <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </handlers>
</system.webServer>

Get safe area inset top and bottom heights

Swift 5 Extension

This can be used as a Extension and called with: UIApplication.topSafeAreaHeight

extension UIApplication {
    static var topSafeAreaHeight: CGFloat {
        var topSafeAreaHeight: CGFloat = 0
         if #available(iOS 11.0, *) {
               let window = UIApplication.shared.windows[0]
               let safeFrame = window.safeAreaLayoutGuide.layoutFrame
               topSafeAreaHeight = safeFrame.minY
             }
        return topSafeAreaHeight
    }
}

Extension of UIApplication is optional, can be an extension of UIView or whatever is preferred, or probably even better a global function.

C# : assign data to properties via constructor vs. instantiating

Object initializers are cool because they allow you to set up a class inline. The tradeoff is that your class cannot be immutable. Consider:

public class Album 
{
    // Note that we make the setter 'private'
    public string Name { get; private set; }
    public string Artist { get; private set; }
    public int Year { get; private set; }

    public Album(string name, string artist, int year)
    {
        this.Name = name;
        this.Artist = artist;
        this.Year = year;
    }
}

If the class is defined this way, it means that there isn't really an easy way to modify the contents of the class after it has been constructed. Immutability has benefits. When something is immutable, it is MUCH easier to determine that it's correct. After all, if it can't be modified after construction, then there is no way for it to ever be 'wrong' (once you've determined that it's structure is correct). When you create anonymous classes, such as:

new { 
    Name = "Some Name",
    Artist = "Some Artist",
    Year = 1994
};

the compiler will automatically create an immutable class (that is, anonymous classes cannot be modified after construction), because immutability is just that useful. Most C++/Java style guides often encourage making members const(C++) or final (Java) for just this reason. Bigger applications are just much easier to verify when there are fewer moving parts.

That all being said, there are situations when you want to be able quickly modify the structure of your class. Let's say I have a tool that I want to set up:

public void Configure(ConfigurationSetup setup);

and I have a class that has a number of members such as:

class ConfigurationSetup {
    public String Name { get; set; }
    public String Location { get; set; }
    public Int32 Size { get; set; }
    public DateTime Time { get; set; }

    // ... and some other configuration stuff... 
}

Using object initializer syntax is useful when I want to configure some combination of properties, but not neccesarily all of them at once. For example if I just want to configure the Name and Location, I can just do:

ConfigurationSetup setup = new ConfigurationSetup {
    Name = "Some Name",
    Location = "San Jose"
};

and this allows me to set up some combination without having to define a new constructor for every possibly permutation.

On the whole, I would argue that making your classes immutable will save you a great deal of development time in the long run, but having object initializer syntax makes setting up certain configuration permutations much easier.

How to set default value to all keys of a dict object in python?

You can use the following class. Just change zero to any default value you like. The solution was tested in Python 2.7.

class cDefaultDict(dict):
    # dictionary that returns zero for missing keys
    # keys with zero values are not stored

    def __missing__(self,key):
        return 0

    def __setitem__(self, key, value):
        if value==0:
            if key in self:  # returns zero anyway, so no need to store it
                del self[key]
        else:
            dict.__setitem__(self, key, value)

How do I POST an array of objects with $.ajax (jQuery or Zepto)

edit: I guess it's now starting to be safe to use the native JSON.stringify() method, supported by most browsers (yes, even IE8+ if you're wondering).

As simple as:

JSON.stringify(yourData)

You should encode you data in JSON before sending it, you can't just send an object like this as POST data.

I recommand using the jQuery json plugin to do so. You can then use something like this in jQuery:

$.post(_saveDeviceUrl, {
    data : $.toJSON(postData)
}, function(response){
    //Process your response here
}
);

"No such file or directory" error when executing a binary

Old question, but hopefully this'll help someone else.

In my case I was using a toolchain on Ubuntu 12.04 that was built on Ubuntu 10.04 (requires GCC 4.1 to build). As most of the libraries have moved to multiarch dirs, it couldn't find ld.so. So, make a symlink for it.

Check required path:

$ readelf -a arm-linux-gnueabi-gcc | grep interpreter:
      [Requesting program interpreter: /lib/ld-linux-x86-64.so.2]

Create symlink:

$ sudo ln -s /lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 /lib/ld-linux-x86-64.so.2

If you're on 32bit, it'll be i386-linux-gnu and not x86_64-linux-gnu.

How to output HTML from JSP <%! ... %> block?

You can't use the 'out' variable (nor any of the other "predeclared" scriptlet variables) inside directives.

The JSP page gets translated by your webserver into a Java servlet. Inside tomcats, for instance, everything inside scriptlets (which start "<%"), along with all the static HTML, gets translated into one giant Java method which writes your page, line by line, to a JspWriter instance called "out". This is why you can use the "out" parameter directly in scriptlets. Directives, on the other hand (which start with "<%!") get translated as separate Java methods.

As an example, a very simple page (let's call it foo.jsp):

<html>
    <head/>
    <body>
        <%!
            String someOutput() {
                return "Some output";
            }
        %>
        <% someOutput(); %>
    </body>
</html>

would end up looking something like this (with a lot of the detail ignored for clarity):

public final class foo_jsp
{
    // This is where the request comes in
    public void _jspService(HttpServletRequest request, HttpServletResponse response) 
        throws IOException, ServletException
    {
        // JspWriter instance is gotten from a factory
        // This is why you can use 'out' directly in scriptlets
        JspWriter out = ...; 

        // Snip

        out.write("<html>");
        out.write("<head/>");
        out.write("<body>");
        out.write(someOutput()); // i.e. write the results of the method call
        out.write("</body>");
        out.write("</html>");
    }

    // Directive gets translated as separate method - note
    // there is no 'out' variable declared in scope
    private String someOutput()
    {
        return "Some output";
    }
}

How to persist data in a dockerized postgres database using volumes

You can create a common volume for all Postgres data

 docker volume create pgdata

or you can set it to the compose file

   version: "3"
   services:
     db:
       image: postgres
       environment:
         - POSTGRES_USER=postgres
         - POSTGRES_PASSWORD=postgress
         - POSTGRES_DB=postgres
       ports:
         - "5433:5432"
       volumes:
         - pgdata:/var/lib/postgresql/data
       networks:
         - suruse
   volumes: 
     pgdata:

It will create volume name pgdata and mount this volume to container's path.

You can inspect this volume

docker volume inspect pgdata

// output will be
[
    {
        "Driver": "local",
        "Labels": {},
        "Mountpoint": "/var/lib/docker/volumes/pgdata/_data",
        "Name": "pgdata",
        "Options": {},
        "Scope": "local"
    }
]

Using "margin: 0 auto;" in Internet Explorer 8

Add <!doctype html> at the top of your HTML output.

Excluding Maven dependencies

You can utilize the dependency management mechanism.

If you create entries in the <dependencyManagement> section of your pom for spring-security-web and spring-web with the desired 3.1.0 version set the managed version of the artifact will override those specified in the transitive dependency tree.

I'm not sure if that really saves you any code, but it is a cleaner solution IMO.

How do I tokenize a string sentence in NLTK?

This is actually on the main page of nltk.org:

>>> import nltk
>>> sentence = """At eight o'clock on Thursday morning
... Arthur didn't feel very good."""
>>> tokens = nltk.word_tokenize(sentence)
>>> tokens
['At', 'eight', "o'clock", 'on', 'Thursday', 'morning',
'Arthur', 'did', "n't", 'feel', 'very', 'good', '.']

ASP.NET 5 MVC: unable to connect to web server 'IIS Express'

For me, this started happening on a project that was working, but then one day I got this error. I tried all suggestions around the .vs folder, applicationhost.config file, changing ports, restarting VS, rebooting Windows, reinstalling IIS Express. Nothing worked. I even created a new bare-bones web app, and got the same error. I have a feeling the IT department made some kind of change to my system.

After I try to run the project and IIS Express has started, in my elevated cmd prompt I run netstat -ano |find "44312" where 44312 is the port number of my web application. I noticed what's returned is not the usual localhost IP (127.0.0.1). It was some external IP. It tells me IIS Express using a different IP.

Then I ran netsh http show iplisten and I see that same IP in the results. netsh http delete iplisten [external ip], and BOOM! the web app loads!

Hide/Show Action Bar Option Menu Item for different fragments

To show action items (action buttons) in the ActionBar of fragments where they are only needed, do this:

Lets say you want the save button to only show in the fragment where you accept input for items and not in the Fragment where you view a list of items, add this to the OnCreateOptionsMenu method of the Fragment where you view the items:

public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {

    if (menu != null) {

        menu.findItem(R.id.action_save_item).setVisible(false);
    }
}

NOTE: For this to work, you need the onCreate() method in your Fragment (where you want to hide item button, the item view fragment in our example) and add setHasOptionsMenu(true) like this:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}

Might not be the best option, but it works and it's simple.

Change image source with JavaScript

The problem was that you were using .src without needing it and you also needed to differentiate which img you wanted to change.

function changeImage(a, imgid) {
    document.getElementById(imgid).src=a;
}
<div id="main_img">
    <img id="img" src="1772031_29_b.jpg">
</div>
<div id="thumb_img">
    <img id="1" src='1772031_29_t.jpg'  onclick='changeImage("1772031_29_b.jpg", "1");'>
    <img id="2" src='1772031_55_t.jpg'  onclick='changeImage("1772031_55_b.jpg", "2");'>
    <img id="3" src='1772031_53_t.jpg'  onclick='changeImage("1772031_53_b.jpg", "3");'>
</div>

What is an Intent in Android?

An intent is an abstract description of an operation to be performed. It can be used with startActivity to launch an Activity, broadcastIntent to send it to any interested BroadcastReceiver components, and startService(Intent) or bindService(Intent, ServiceConnection, int) to communicate with a background Service.

For more details see these links :

1). http://developer.android.com/reference/android/content/Intent.html

2) http://developer.android.com/guide/topics/intents/intents-filters.html

3). http://www.vogella.de/articles/AndroidIntent/article.html

there are many more articles are available.

Python: Removing list element while iterating over list

You could always iterate over a copy of the list, leaving you free to modify the original:

for item in list(somelist):
  ...
  somelist.remove(item)

The controller for path was not found or does not implement IController

In my case namespaces parameter was not matching the namespace of the controller.

public override void RegisterArea(AreaRegistrationContext context) 
{
    context.MapRoute(
        "Admin_default",
        "Admin/{controller}/{action}/{id}",
        new {controller = "Home", action = "Index", id = UrlParameter.Optional },
        namespaces: new[] { "Web.Areas.Admin.Controllers" }
    );
}

how to query LIST using linq

Since you haven't given any indication to what you want, here is a link to 101 LINQ samples that use all the different LINQ methods: 101 LINQ Samples

Also, you should really really really change your List into a strongly typed list (List<T>), properly define T, and add instances of T to your list. It will really make the queries much easier since you won't have to cast everything all the time.

How to copy folders to docker image from Dockerfile?

the simplest way:

sudo docker cp path/on/your/machine adam_ubuntu:/root/path_in_container

Note putting into the root path if you are copying something that needs to be picked up by the root using ~.

Import a module from a relative path

You could also add the subdirectory to your Python path so that it imports as a normal script.

import sys
sys.path.insert(0, <path to dirFoo>)
import Bar

Creating Duplicate Table From Existing Table

Use this query to create the new table with the values from existing table

CREATE TABLE New_Table_name AS SELECT * FROM Existing_table_Name; 

Now you can get all the values from existing table into newly created table.

How to combine 2 plots (ggplot) into one plot?

Creating a single combined plot with your current data set up would look something like this

p <- ggplot() +
      # blue plot
      geom_point(data=visual1, aes(x=ISSUE_DATE, y=COUNTED)) + 
      geom_smooth(data=visual1, aes(x=ISSUE_DATE, y=COUNTED), fill="blue",
        colour="darkblue", size=1) +
      # red plot
      geom_point(data=visual2, aes(x=ISSUE_DATE, y=COUNTED)) + 
      geom_smooth(data=visual2, aes(x=ISSUE_DATE, y=COUNTED), fill="red",
        colour="red", size=1)

however if you could combine the data sets before plotting then ggplot will automatically give you a legend, and in general the code looks a bit cleaner

visual1$group <- 1
visual2$group <- 2

visual12 <- rbind(visual1, visual2)

p <- ggplot(visual12, aes(x=ISSUE_DATE, y=COUNTED, group=group, col=group, fill=group)) +
      geom_point() +
      geom_smooth(size=1)

Where is the Docker daemon log?

Docker for Mac (Beta)

~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/log/d??ocker.log

What is the best way to delete a component with CLI

I wrote a bash script that should automate the process written by Yakov Fain below. It can be called like ./removeComponent myComponentName This has only been tested with Angular 6

#!/bin/bash
if [ "$#" -ne 1 ]; then
    echo "Input a component to delete"
    exit 1
fi

# finds folder with component name and deletes
find . -type d -name $1 | xargs rm -rf

# removes lines referencing the component from app.module.ts
grep -v $1 app.module.ts > temp
mv temp app.module.ts

componentName=$1
componentName+="Component"

grep -v -i $componentName app.module.ts > temp
mv temp app.module.ts

How to add "active" class to Html.ActionLink in ASP.NET MVC

This solution is simple for Asp.net MCV 5.

  1. Create a static class, for example Utilitarios.cs.

  2. Inside the Class create a static method:

    public static string IsLinkActive(this UrlHelper url, string action, string controller)
    {
        if (url.RequestContext.RouteData.Values["controller"].ToString() == controller &&
            url.RequestContext.RouteData.Values["action"].ToString() == action)
        {
            return "active";
        }
    
        return "";
    }
    
  3. call like this

    <ul class="sidebar-menu" data-widget="tree">
        <li class="header">HEADER</li>
        <li class="@Url.IsLinkActive("Index", "Home")">
            <a href="@Url.Action("Index", "Home")"><i class="fa fa-link"></i> <span>Home</span></a>
        </li>
        <li class="@Url.IsLinkActive("About", "Home")">
            <a href="@Url.Action("About", "Home")"><i class="fa fa-link"></i><span>About</span></a>
        </li>
    </ul>
    

How to pass datetime from c# to sql correctly?

You've already done it correctly by using a DateTime parameter with the value from the DateTime, so it should already work. Forget about ToString() - since that isn't used here.

If there is a difference, it is most likely to do with different precision between the two environments; maybe choose a rounding (seconds, maybe?) and use that. Also keep in mind UTC/local/unknown (the DB has no concept of the "kind" of date; .NET does).

I have a table and the date-times in it are in the format: 2011-07-01 15:17:33.357

Note that datetimes in the database aren't in any such format; that is just your query-client showing you white lies. It is stored as a number (and even that is an implementation detail), because humans have this odd tendency not to realise that the date you've shown is the same as 40723.6371916281. Stupid humans. By treating it simply as a "datetime" throughout, you shouldn't get any problems.

Syntax for creating a two-dimensional array in Java

It is also possible to declare it the following way. It's not good design, but it works.

int[] twoDimIntArray[] = new int[5][10];

Get the element with the highest occurrence in an array

function mode(){
  var input = $("input").val().split(",");
  var mode = [];
  var m = [];
  var p = [];
    for(var x = 0;x< input.length;x++){
      if(m.indexOf(input[x])==-1){
        m[m.length]=input[x];
    }}
  for(var x = 0; x< m.length;x++){
    p[x]=0;
    for(var y = 0; y<input.length;y++){
      if(input[y]==m[x]){
      p[x]++; 
 }}}
 for(var x = 0;x< p.length;x++){
   if(p[x] ==(Math.max.apply(null, p))){
     mode.push(m[x]);
 }} 
$("#output").text(mode);}

How does setTimeout work in Node.JS?

setTimeout is a kind of Thread, it holds a operation for a given time and execute.

setTimeout(function,time_in_mills);

in here the first argument should be a function type; as an example if you want to print your name after 3 seconds, your code should be something like below.

setTimeout(function(){console.log('your name')},3000);

Key point to remember is, what ever you want to do by using the setTimeout method, do it inside a function. If you want to call some other method by parsing some parameters, your code should look like below:

setTimeout(function(){yourOtherMethod(parameter);},3000);

AttributeError: 'datetime' module has no attribute 'strptime'

If I had to guess, you did this:

import datetime

at the top of your code. This means that you have to do this:

datetime.datetime.strptime(date, "%Y-%m-%d")

to access the strptime method. Or, you could change the import statement to this:

from datetime import datetime

and access it as you are.

The people who made the datetime module also named their class datetime:

#module  class    method
datetime.datetime.strptime(date, "%Y-%m-%d")

How to use Object.values with typescript?

Simplest way is to cast the Object to any, like this:

const data = {"Ticket-1.pdf":"8e6e8255-a6e9-4626-9606-4cd255055f71.pdf","Ticket-2.pdf":"106c3613-d976-4331-ab0c-d581576e7ca1.pdf"};
const obj = <any>Object;
const values = obj.values(data).map(x => x.substr(0, x.length - 4));
const commaJoinedValues = values.join(',');
console.log(commaJoinedValues);

And voila – no compilation errors ;)

asynchronous vs non-blocking

They differ in spelling only. There is no difference in what they refer to. To be technical you could say they differ in emphasis. Non blocking refers to control flow(it doesn't block.) Asynchronous refers to when the event\data is handled(not synchronously.)

How can I find my Apple Developer Team id and Team Agent Apple ID?

For personal teams

grep DEVELOPMENT_TEAM MyProject.xcodeproj/project.pbxproj

should give you the team ID

DEVELOPMENT_TEAM = ZU88ND8437;

Store an array in HashMap

If you want to store multiple values for a key (if I understand you correctly), you could try a MultiHashMap (available in various libraries, not only commons-collections).

How to support UTF-8 encoding in Eclipse

You can set a default encoding-set whenever you run eclipse.exe.

  1. Open eclipse.ini in your eclipse home directory Or STS.ini in case of STS(Spring Tool Suite)
  2. put the line below at the end of the file

-Dfile.encoding=UTF-8