Programs & Examples On #Content expiration

How to check if a string starts with "_" in PHP?

$variable[0] != "_"

How does it work?

In PHP you can get particular character of a string with array index notation. $variable[0] is the first character of a string (if $variable is a string).

An exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll

use try-catch to see real error occurred on you

 try
{
  //Your insert code here
}
catch (System.Data.SqlClient.SqlException sqlException)
{
  System.Windows.Forms.MessageBox.Show(sqlException.Message);
}

How to increase image size of pandas.DataFrame.plot in jupyter notebook?

Try figsize param in df.plot(figsize=(width,height)):

df = pd.DataFrame({"a":[1,2],"b":[1,2]})
df.plot(figsize=(3,3));

enter image description here

df = pd.DataFrame({"a":[1,2],"b":[1,2]})
df.plot(figsize=(5,3));

enter image description here

The size in figsize=(5,3) is given in inches per (width, height)

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.plot.html

Regex AND operator

It is impossible for both (?=foo) and (?=baz) to match at the same time. It would require the next character to be both f and b simultaneously which is impossible.

Perhaps you want this instead:

(?=.*foo)(?=.*baz)

This says that foo must appear anywhere and baz must appear anywhere, not necessarily in that order and possibly overlapping (although overlapping is not possible in this specific case because the letters themselves don't overlap).

Excel formula to get cell color

No, you can only get to the interior color of a cell by using a Macro. I am afraid. It's really easy to do (cell.interior.color) so unless you have a requirement that restricts you from using VBA, I say go for it.

Why I can't change directories using "cd"?

If you are using fish as your shell, the best solution is to create a function. As an example, given the original question, you could copy the 4 lines below and paste them into your fish command line:

function proj
   cd /home/tree/projects/java
end
funcsave proj

This will create the function and save it for use later. If your project changes, just repeat the process using the new path.

If you prefer, you can manually add the function file by doing the following:

nano ~/.config/fish/functions/proj.fish

and enter the text:

function proj
   cd /home/tree/projects/java
end

and finally press ctrl+x to exit and y followed by return to save your changes.

(NOTE: the first method of using funcsave creates the proj.fish file for you).

ES6 map an array of objects, to return an array of objects with new keys

You just need to wrap object in ()

_x000D_
_x000D_
var arr = [{_x000D_
  id: 1,_x000D_
  name: 'bill'_x000D_
}, {_x000D_
  id: 2,_x000D_
  name: 'ted'_x000D_
}]_x000D_
_x000D_
var result = arr.map(person => ({ value: person.id, text: person.name }));_x000D_
console.log(result)
_x000D_
_x000D_
_x000D_

Static Vs. Dynamic Binding in Java

From Javarevisited blog post:

Here are a few important differences between static and dynamic binding:

  1. Static binding in Java occurs during compile time while dynamic binding occurs during runtime.
  2. private, final and static methods and variables use static binding and are bonded by compiler while virtual methods are bonded during runtime based upon runtime object.
  3. Static binding uses Type (class in Java) information for binding while dynamic binding uses object to resolve binding.
  4. Overloaded methods are bonded using static binding while overridden methods are bonded using dynamic binding at runtime.

Here is an example which will help you to understand both static and dynamic binding in Java.

Static Binding Example in Java

public class StaticBindingTest {  
    public static void main(String args[]) {
        Collection c = new HashSet();
        StaticBindingTest et = new StaticBindingTest();
        et.sort(c);
    }
    //overloaded method takes Collection argument
    public Collection sort(Collection c) {
        System.out.println("Inside Collection sort method");
        return c;
    }
    //another overloaded method which takes HashSet argument which is sub class
    public Collection sort(HashSet hs) {
        System.out.println("Inside HashSet sort method");
        return hs;
    }
}

Output: Inside Collection sort method

Example of Dynamic Binding in Java

public class DynamicBindingTest {   
    public static void main(String args[]) {
        Vehicle vehicle = new Car(); //here Type is vehicle but object will be Car
        vehicle.start(); //Car's start called because start() is overridden method
    }
}

class Vehicle {
    public void start() {
        System.out.println("Inside start method of Vehicle");
    }
}

class Car extends Vehicle {
    @Override
    public void start() {
        System.out.println("Inside start method of Car");
    }
}

Output: Inside start method of Car

how to check if input field is empty

Why don't u use:

<script>
$('input').keyup(function(){
if(($('#eng').val().length > 0) && ($('#spa').val().length > 0))
    $("#submit").prop('disabled', false);
else
    $("#submit").prop('disabled', true);
});
</script>

Then delete the onkeyup function on the input.

Select option padding not working in chrome

It seems that

Unfortunately, webkit browsers do not support styling of option tags yet.

you may find similar question here

  1. How to style a select tag's option element?
  2. Styling option value in select drop down html not work on Chrome & Safari

The most widely used cross browser solution is to use ul li

Hope it helps!

What does the JSLint error 'body of a for in should be wrapped in an if statement' mean?

This means that you should filter the properties of evtListeners with the hasOwnProperty method.

Return list using select new in LINQ

public List<Object> GetProjectForCombo()
{
    using (MyDataContext db = new MyDataContext (DBHelper.GetConnectionString()))
     {
         var query = from pro in db.Projects
                     select new {pro.ProjectName,pro.ProjectId};

         return query.ToList<Object>();
    }
}

How to check if the user can go back in browser history or not

A solution that actually works

window.history.length == 1

This works on Chrome, Firefox, and Edge. You can use the following piece of JQuery code that worked for me on the latest versions of all of the above 3 browsers if you want to hide or remove a back button on your developed web page when there is no window history.

$(window).load(function() {
        if (window.history.length == 1) {
            $("#back-button").remove();
        }
    })

How to stop/shut down an elasticsearch node?

Updated answer.

_shutdown API has been removed in elasticsearch 2.x.

Some options:

  • In your terminal (dev mode basically), just type "Ctrl-C"

  • If you started it as a daemon (-d) find the PID and kill the process: SIGTERM will shut Elasticsearch down cleanly (kill -15 PID)

  • If running as a service, run something like service elasticsearch stop:

Previous answer. It's now deprecated from 1.6.

Yeah. See admin cluster nodes shutdown documentation

Basically:

# Shutdown local node
$ curl -XPOST 'http://localhost:9200/_cluster/nodes/_local/_shutdown'

# Shutdown all nodes in the cluster
$ curl -XPOST 'http://localhost:9200/_shutdown'

Calling the base class constructor from the derived class constructor

but I can't initialize my derived class, I mean I did this Inheritance so I can add animals to my PetStore but now since sizeF is private how can I do that ?? so I'm thinking maybe in the PetStore default constructor I can call Farm()... so any Idea ???

Don't panic.

Farm constructor will be called in the constructor of PetStore, automatically.

See the base class inheritance calling rules: What are the rules for calling the superclass constructor?

Enable remote connections for SQL Server Express 2012

I had to add port via Configuration Manager and add the port number in my sql connection [host]\[db instance name],1433

Note the , (comma) between instancename and port

How to delete Certain Characters in a excel 2010 cell

Another option: =MID(A1,2,LEN(A1)-2)

Or this (for fun): =RIGHT(LEFT(A1,LEN(A1)-1),LEN(LEFT(A1,LEN(A1)-1))-1)

Android Activity without ActionBar

Considering everyone is posting older ways of hiding the ActionBar here is the proper way of implementing it within styles for AppCompat support library. Which I highly suggest moving toward if you haven't already.

Simply removing the ActionBar

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
</style>

If you are using the appcompat support libraries, this is the easiest and recommended way of hiding the ActionBar to make full screen or start implementing to toolbar within your layouts.

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Your Toolbar Color-->
    <item name="colorPrimary">@color/primary</item>

    <!-- colorPrimaryDark is used for the status bar -->
    <item name="colorPrimaryDark">@color/primary_dark</item>

    <!-- colorAccent is used as the default value for colorControlActivated,
     which is used to tint widgets -->
    <item name="colorAccent">@color/accent</item>

    <!-- You can also set colorControlNormal, colorControlActivated
     colorControlHighlight, and colorSwitchThumbNormal. -->
</style>

Then to change your toolbar color

<android.support.v7.widget.Toolbar
    android:id=”@+id/my_awesome_toolbar”
    android:layout_height=”wrap_content”
    android:layout_width=”match_parent”
    android:minHeight=”?attr/actionBarSize”
    android:background=”?attr/primary” />

Last note: Your Activity class should extend AppCompatActivity

public class MainActivity extends AppCompatActivity {

<!--Activity Items -->

}

How to upgrade PowerShell version from 2.0 to 3.0

Just run this in a console.

@powershell -NoProfile -ExecutionPolicy unrestricted -Command "iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))" && SET PATH=%PATH%;%systemdrive%\chocolatey\bin
cinst powershell

It installs the latest version using a Chocolatey repository.

Originally I was using command cinst powershell 3.0.20121027, but it looks like it later stopped working. Since this question is related to PowerShell 3.0 this was the right way. At this moment (June 26, 2014) cinst powershell refers to version 3.0 of PowerShell, and that may change in future.

See the Chocolatey PowerShell package page for details on what version will be installed.

Can I use VARCHAR as the PRIMARY KEY?

Of course you can, in the sense that your RDBMS will let you do it. The answer to a question of whether or not you should do it is different, though: in most situations, values that have a meaning outside your database system should not be chosen to be a primary key.

If you know that the value is unique in the system that you are modeling, it is appropriate to add a unique index or a unique constraint to your table. However, your primary key should generally be some "meaningless" value, such as an auto-incremented number or a GUID.

The rationale for this is simple: data entry errors and infrequent changes to things that appear non-changeable do happen. They become much harder to fix on values which are used as primary keys.

substring index range

The substring starts at, and includes the character at the location of the first number given and goes to, but does not include the character at the last number given.

How can I increment a char?

I came from PHP, where you can increment char (A to B, Z to AA, AA to AB etc.) using ++ operator. I made a simple function which does the same in Python. You can also change list of chars to whatever (lowercase, uppercase, etc.) is your need.

# Increment char (a -> b, az -> ba)
def inc_char(text, chlist = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'):
    # Unique and sort
    chlist = ''.join(sorted(set(str(chlist))))
    chlen = len(chlist)
    if not chlen:
        return ''
    text = str(text)
    # Replace all chars but chlist
    text = re.sub('[^' + chlist + ']', '', text)
    if not len(text):
        return chlist[0]
    # Increment
    inc = ''
    over = False
    for i in range(1, len(text)+1):
        lchar = text[-i]
        pos = chlist.find(lchar) + 1
        if pos < chlen:
            inc = chlist[pos] + inc
            over = False
            break
        else:
            inc = chlist[0] + inc
            over = True
    if over:
        inc += chlist[0]
    result = text[0:-len(inc)] + inc
    return result

Can you create nested WITH clauses for Common Table Expressions?

we can create nested cte.please see the below cte in example

;with cte_data as 
(
Select * from [HumanResources].[Department]
),cte_data1 as
(
Select * from [HumanResources].[Department]
)

select * from cte_data,cte_data1

Get Selected Item Using Checkbox in Listview

"The use of the checkbox is to determine what Item in the Listview that I selected"

  1. Just add the tag to checkbox using setTag() method in the Adapter class. and other side using getTag() method.

          @Override
       public void onBindViewHolder(MyViewHolder holder, int position) {
    
    ServiceHelper helper=userServices.get(position);
    holder.tvServiceName.setText(helper.getServiceName());
    
    if(!helper.isServiceStatus()){
    
        holder.btnAdd.setVisibility(View.VISIBLE);
        holder.btnAdd.setTag(helper.getServiceName());
        holder.checkBoxServiceStatus.setVisibility(View.INVISIBLE);
    
    }else{
    
        holder.checkBoxServiceStatus.setVisibility(View.VISIBLE);
           //This Line
        holder.checkBoxServiceStatus.setTag(helper.getServiceName());
        holder.btnAdd.setVisibility(View.INVISIBLE);
    
       }
    
    }
    
  2. In xml code of the checkbox just put the "android:onClick="your method""attribute.

         <CheckBox
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:onClick="checkboxClicked"  
                android:id="@+id/checkBox_Service_row"
                android:layout_marginRight="5dp"
                android:layout_alignParentTop="true"
                android:layout_alignParentRight="true"
                android:layout_alignParentEnd="true" />
    
  3. In your class Implement that method "your method".

         protected void checkboxClicked(View view)
          {
    
            CheckBox checkBox=(CheckBox) view;
              String tagName="";
             if(checkBox.isChecked()){
               tagName=checkBox.getTag().toString();
               deleteServices.add(tagName);
               checkboxArrayList.add(checkBox);
            }else {
                   checkboxArrayList.remove(checkBox);
                   tagName=checkBox.getTag().toString();
                        if(deleteServices.size()>0&&deleteServices.contains(tagName)){
     deleteServices.remove(tagName);
        }
      }
    }
    

How to pass parameters on onChange of html select

For how to do it in jQuery:

<select id="yourid">
<option value="Value 1">Text 1</option>
<option value="Value 2">Text 2</option>
</select>

<script src="jquery.js"></script>
<script>
$('#yourid').change(function() {
  alert('The option with value ' + $(this).val() + ' and text ' + $(this).text() + ' was selected.');
});
</script>

You should also know that Javascript and jQuery are not identical. jQuery is valid JavaScript code, but not all JavaScript is jQuery. You should look up the differences and make sure you are using the appropriate one.

Javascript: How to loop through ALL DOM elements on a page?

Here is another example on how you can loop through a document or an element:

function getNodeList(elem){
var l=new Array(elem),c=1,ret=new Array();
//This first loop will loop until the count var is stable//
for(var r=0;r<c;r++){
    //This loop will loop thru the child element list//
    for(var z=0;z<l[r].childNodes.length;z++){

         //Push the element to the return array.
        ret.push(l[r].childNodes[z]);

        if(l[r].childNodes[z].childNodes[0]){
            l.push(l[r].childNodes[z]);c++;
        }//IF           
    }//FOR
}//FOR
return ret;
}

How do I mock an open used in a with statement (using the Mock framework in Python)?

Python 3

Patch builtins.open and use mock_open, which is part of the mock framework. patch used as a context manager returns the object used to replace the patched one:

from unittest.mock import patch, mock_open
with patch("builtins.open", mock_open(read_data="data")) as mock_file:
    assert open("path/to/open").read() == "data"
    mock_file.assert_called_with("path/to/open")

If you want to use patch as a decorator, using mock_open()'s result as the new= argument to patch can be a little bit weird. Instead, use patch's new_callable= argument and remember that every extra argument that patch doesn't use will be passed to the new_callable function, as described in the patch documentation:

patch() takes arbitrary keyword arguments. These will be passed to the Mock (or new_callable) on construction.

@patch("builtins.open", new_callable=mock_open, read_data="data")
def test_patch(mock_file):
    assert open("path/to/open").read() == "data"
    mock_file.assert_called_with("path/to/open")

Remember that in this case patch will pass the mocked object as an argument to your test function.

Python 2

You need to patch __builtin__.open instead of builtins.open and mock is not part of unittest, you need to pip install and import it separately:

from mock import patch, mock_open
with patch("__builtin__.open", mock_open(read_data="data")) as mock_file:
    assert open("path/to/open").read() == "data"
    mock_file.assert_called_with("path/to/open")

How to catch all exceptions in c# using try and catch?

try
{

..
..
..

}

catch(Exception ex)
{

..
..
..

}

the Exception ex means all the exceptions.

Is there a JavaScript / jQuery DOM change listener?

For a long time, DOM3 mutation events were the best available solution, but they have been deprecated for performance reasons. DOM4 Mutation Observers are the replacement for deprecated DOM3 mutation events. They are currently implemented in modern browsers as MutationObserver (or as the vendor-prefixed WebKitMutationObserver in old versions of Chrome):

MutationObserver = window.MutationObserver || window.WebKitMutationObserver;

var observer = new MutationObserver(function(mutations, observer) {
    // fired when a mutation occurs
    console.log(mutations, observer);
    // ...
});

// define what element should be observed by the observer
// and what types of mutations trigger the callback
observer.observe(document, {
  subtree: true,
  attributes: true
  //...
});

This example listens for DOM changes on document and its entire subtree, and it will fire on changes to element attributes as well as structural changes. The draft spec has a full list of valid mutation listener properties:

childList

  • Set to true if mutations to target's children are to be observed.

attributes

  • Set to true if mutations to target's attributes are to be observed.

characterData

  • Set to true if mutations to target's data are to be observed.

subtree

  • Set to true if mutations to not just target, but also target's descendants are to be observed.

attributeOldValue

  • Set to true if attributes is set to true and target's attribute value before the mutation needs to be recorded.

characterDataOldValue

  • Set to true if characterData is set to true and target's data before the mutation needs to be recorded.

attributeFilter

  • Set to a list of attribute local names (without namespace) if not all attribute mutations need to be observed.

(This list is current as of April 2014; you may check the specification for any changes.)

cartesian product in pandas

This won't win a code golf competition, and borrows from the previous answers - but clearly shows how the key is added, and how the join works. This creates 2 new data frames from lists, then adds the key to do the cartesian product on.

My use case was that I needed a list of all store IDs on for each week in my list. So, I created a list of all the weeks I wanted to have, then a list of all the store IDs I wanted to map them against.

The merge I chose left, but would be semantically the same as inner in this setup. You can see this in the documentation on merging, which states it does a Cartesian product if key combination appears more than once in both tables - which is what we set up.

days = pd.DataFrame({'date':list_of_days})
stores = pd.DataFrame({'store_id':list_of_stores})
stores['key'] = 0
days['key'] = 0
days_and_stores = days.merge(stores, how='left', on = 'key')
days_and_stores.drop('key',1, inplace=True)

What is Hash and Range Primary Key?

A well-explained answer is already given by @mkobit, but I will add a big picture of the range key and hash key.

In a simple words range + hash key = composite primary key CoreComponents of Dynamodb enter image description here

A primary key is consists of a hash key and an optional range key. Hash key is used to select the DynamoDB partition. Partitions are parts of the table data. Range keys are used to sort the items in the partition, if they exist.

So both have a different purpose and together help to do complex query. In the above example hashkey1 can have multiple n-range. Another example of range and hashkey is game, userA(hashkey) can play Ngame(range)

enter image description here

The Music table described in Tables, Items, and Attributes is an example of a table with a composite primary key (Artist and SongTitle). You can access any item in the Music table directly, if you provide the Artist and SongTitle values for that item.

A composite primary key gives you additional flexibility when querying data. For example, if you provide only the value for Artist, DynamoDB retrieves all of the songs by that artist. To retrieve only a subset of songs by a particular artist, you can provide a value for Artist along with a range of values for SongTitle.

enter image description here

https://www.slideshare.net/InfoQ/amazon-dynamodb-design-patterns-best-practices https://www.slideshare.net/AmazonWebServices/awsome-day-2016-module-4-databases-amazon-dynamodb-and-amazon-rds https://ceyhunozgun.blogspot.com/2017/04/implementing-object-persistence-with-dynamodb.html

How to close an iframe within iframe itself

Use this to remove iframe from parent within iframe itself

frameElement.parentNode.removeChild(frameElement)

It works with same origin only(not allowed with cross origin)

http://localhost:8080/ Access Error: 404 -- Not Found Cannot locate document: /

your 8080 port is already used by another application 1/ you can try to find out which app is using it, using "netstat -aon" and stop the process; 2/ you can go to server.xml and change from port 8080 to another one (ex: 8081)

Cannot get Kerberos service ticket: KrbException: Server not found in Kerberos database (7)

"Server not found in Kerberos database" error can happen if you have registered the SPN to multiple users/computers.

You can check that with:

$ SetSPN -Q ServicePrincipalName
( SetSPN -Q HTTP/my.server.local@MYDOMAIN )

Why isn't this code to plot a histogram on a continuous value Pandas column working?

EDIT:

After your comments this actually makes perfect sense why you don't get a histogram of each different value. There are 1.4 million rows, and ten discrete buckets. So apparently each bucket is exactly 10% (to within what you can see in the plot).


A quick rerun of your data:

In [25]: df.hist(column='Trip_distance')

enter image description here

Prints out absolutely fine.

The df.hist function comes with an optional keyword argument bins=10 which buckets the data into discrete bins. With only 10 discrete bins and a more or less homogeneous distribution of hundreds of thousands of rows, you might not be able to see the difference in the ten different bins in your low resolution plot:

In [34]: df.hist(column='Trip_distance', bins=50)

enter image description here

Adding external library into Qt Creator project

Are you using qmake projects? If so, you can add an external library using the LIBS variable. E.g:

win32:LIBS += path/to/Psapi.lib

Hook up Raspberry Pi via Ethernet to laptop without router?

You could use a cross-over ethernet cable - http://en.wikipedia.org/wiki/Ethernet_crossover_cable

Assuming your RPi is a DCHP Client, then best to run a simple DHCP server on your notebook to assign the RPi an IP address.

how to customise input field width in bootstrap 3

i solved with a max-width in my main css-file.

/* Set width on the form input elements since they're 100% wide by default */
input,
select,
textarea {
    max-width: 280px;
}

It's a simple solution with little "code"

Second line in li starts under the bullet after CSS-reset

The li tag has a property called list-style-position. This makes your bullets inside or outside the list. On default, it’s set to inside. That makes your text wrap around it. If you set it to outside, the text of your li tags will be aligned.

The downside of that is that your bullets won't be aligned with the text outside the ul. If you want to align it with the other text you can use a margin.

ul li {
    /*
     * We want the bullets outside of the list,
     * so the text is aligned. Now the actual bullet
     * is outside of the list’s container
     */
    list-style-position: outside;

    /*
     * Because the bullet is outside of the list’s
     * container, indent the list entirely
     */
    margin-left: 1em;
}

Edit 15th of March, 2014 Seeing people are still coming in from Google, I felt like the original answer could use some improvement

  • Changed the code block to provide just the solution
  • Changed the indentation unit to em’s
  • Each property is applied to the ul element
  • Good comments :)

Enabling the OpenSSL in XAMPP

Yes, you must open php.ini and remove the semicolon to:

;extension=php_openssl.dll

If you don't have that line, check that you have the file (In my PC is on D:\xampp\php\ext) and add this to php.ini in the "Dynamic Extensions" section:

extension=php_openssl.dll

Things have changed for PHP > 7. This is what i had to do for PHP 7.2.

Step: 1: Uncomment extension=openssl

Step: 2: Uncomment extension_dir = "ext"

Step: 3: Restart xampp.

Done.

Explanation: ( From php.ini )

If you wish to have an extension loaded automatically, use the following syntax:

extension=modulename

Note : The syntax used in previous PHP versions (extension=<ext>.so and extension='php_<ext>.dll) is supported for legacy reasons and may be deprecated in a future PHP major version. So, when it is possible, please move to the new (extension=<ext>) syntax.

Special Note: Be sure to appropriately set the extension_dir directive.

DateTime format to SQL format using C#

The Answer i was looking for was:

DateTime myDateTime = DateTime.Now;
string sqlFormattedDate = myDateTime.ToString("yyyy-MM-dd HH:mm:ss");

I've also learned that you can do it this way:

DateTime myDateTime = DateTime.Now;
string sqlFormattedDate = myDateTime.ToString(myCountryDateFormat);

where myCountryDateFormat can be changed to meet change depending on requirement.

Please note that the tagged "This question may already have an answer here:" has not actually answered the question because as you can see it used a ".Date" instead of omitting it. It's quite confusing for new programmers of .NET

Capitalize the first letter of string in AngularJs

For the AngularJS from meanjs.org, I place the custom filters in modules/core/client/app/init.js

I needed a custom filter to capitalize each word in a sentence, here is how I do so:

angular.module(ApplicationConfiguration.applicationModuleName).filter('capitalize', function() {
return function(str) {
    return str.split(" ").map(function(input){return (!!input) ? input.charAt(0).toUpperCase() + input.substr(1).toLowerCase() :         ''}).join(" ");

}
});

The credit of the map function goes to @Naveen raj

Which Radio button in the group is checked?

Sometimes in situations like this I miss my youth, when Access was my poison of choice, and I could give each radio button in a group its own value.

My hack in C# is to use the tag to set the value, and when I make a selection from the group, I read the value of the tag of the selected radiobutton. In this example, directionGroup is the group in which I have four five radio buttons with "None" and "NE", "SE", "NW" and "SW" as the tags on the other four radiobuttons.

I proactively used a button to capture the value of the checked button, because because assigning one event handler to all of the buttons' CHeckCHanged event causes EACH button to fire, because changing one changes them all. So the value of sender is always the first RadioButton in the group. Instead, I use this method when I need to find out which one is selected, with the values I want to retrieve in the Tag property of each RadioButton.

  private void ShowSelectedRadioButton()
    {
        List<RadioButton> buttons = new List<RadioButton>();
        string selectedTag = "No selection";
        foreach (Control c in directionGroup.Controls)
        {
            if (c.GetType() == typeof(RadioButton))
            {
                buttons.Add((RadioButton)c);
            }
        }
        var selectedRb = (from rb in buttons where rb.Checked == true select rb).FirstOrDefault();
        if (selectedRb!=null)
        {
             selectedTag = selectedRb.Tag.ToString();
        }

        FormattableString result = $"Selected Radio button tag ={selectedTag}";
        MessageBox.Show(result.ToString());
    }

FYI, I have tested and used this in my work.

Joey

Tkinter: "Python may not be configured for Tk"

You need to install tkinter for python3.

On Fedora pip3 install tkinter --user returns Could not find a version that satisfies the requirement... so I have to command: dnf install python3-tkinter. This have solved my problem

jQuery calculate sum of values in all text fields

A tad more generic copy/paste function for your project.

sumjq = function(selector) {
    var sum = 0;
    $(selector).each(function() {
        sum += Number($(this).text());
    });
    return sum;
}

console.log(sumjq('.price'));

Difference between timestamps with/without time zone in PostgreSQL

I try to explain it more understandably than the referred PostgreSQL documentation.

Neither TIMESTAMP variants store a time zone (or an offset), despite what the names suggest. The difference is in the interpretation of the stored data (and in the intended application), not in the storage format itself:

  • TIMESTAMP WITHOUT TIME ZONE stores local date-time (aka. wall calendar date and wall clock time). Its time zone is unspecified as far as PostgreSQL can tell (though your application may knows what it is). Hence, PostgreSQL does no time zone related conversion on input or output. If the value was entered into the database as '2011-07-01 06:30:30', then no mater in what time zone you display it later, it will still say year 2011, month 07, day 01, 06 hours, 30 minutes, and 30 seconds (in some format). Also, any offset or time zone you specify in the input is ignored by PostgreSQL, so '2011-07-01 06:30:30+00' and '2011-07-01 06:30:30+05' are the same as just '2011-07-01 06:30:30'. For Java developers: it's analogous to java.time.LocalDateTime.

  • TIMESTAMP WITH TIME ZONE stores a point on the UTC time line. How it looks (how many hours, minutes, etc.) depends on your time zone, but it always refers to the same "physical" instant (like the moment of an actual physical event). The input is internally converted to UTC, and that's how it's stored. For that, the offset of the input must be known, so when the input contains no explicit offset or time zone (like '2011-07-01 06:30:30') it's assumed to be in the current time zone of the PostgreSQL session, otherwise the explicitly specified offset or time zone is used (as in '2011-07-01 06:30:30+05'). The output is displayed converted to the current time zone of the PostgreSQL session. For Java developers: It's analogous to java.time.Instant (with lower resolution though), but with JDBC and JPA 2.2 you are supposed to map it to java.time.OffsetDateTime (or to java.util.Date or java.sql.Timestamp of course).

Some say that both TIMESTAMP variations store UTC date-time. Kind of, but it's confusing to put it that way in my opinion. TIMESTAMP WITHOUT TIME ZONE is stored like a TIMESTAMP WITH TIME ZONE, which rendered with UTC time zone happens to give the same year, month, day, hours, minutes, seconds, and microseconds as they are in the local date-time. But it's not meant to represent the point on the time line that the UTC interpretation says, it's just the way the local date-time fields are encoded. (It's some cluster of dots on the time line, as the real time zone is not UTC; we don't know what it is.)

WARNING: Exception encountered during context initialization - cancelling refresh attempt

  1. To closed ideas,
  2. To remove all folder and file C:/Users/UserName/.m2/org/*,
  3. Open ideas and update Maven project,(right click on project -> maven->update maven project)
  4. After that update the project.

How to tag an older commit in Git?

Just the Code

# Set the HEAD to the old commit that we want to tag
git checkout 9fceb02

# temporarily set the date to the date of the HEAD commit, and add the tag
GIT_COMMITTER_DATE="$(git show --format=%aD | head -1)" \
git tag -a v1.2 -m"v1.2"

# set HEAD back to whatever you want it to be
git checkout master

Details

The answer by @dkinzer creates tags whose date is the current date (when you ran the git tag command), not the date of the commit. The Git help for tag has a section "On Backdating Tags" which says:

If you have imported some changes from another VCS and would like to add tags for major releases of your work, it is useful to be able to specify the date to embed inside of the tag object; such data in the tag object affects, for example, the ordering of tags in the gitweb interface.

To set the date used in future tag objects, set the environment variable GIT_COMMITTER_DATE (see the later discussion of possible values; the most common form is "YYYY-MM-DD HH:MM").

For example:

$ GIT_COMMITTER_DATE="2006-10-02 10:31" git tag -s v1.0.1

The page "How to Tag in Git" shows us that we can extract the time of the HEAD commit via:

git show --format=%aD  | head -1
#=> Wed, 12 Feb 2014 12:36:47 -0700

We could extract the date of a specific commit via:

GIT_COMMITTER_DATE="$(git show 9fceb02 --format=%aD | head -1)" \
git tag -a v1.2 9fceb02 -m "v1.2"

However, instead of repeating the commit twice, it seems easier to just change the HEAD to that commit and use it implicitly in both commands:

git checkout 9fceb02 

GIT_COMMITTER_DATE="$(git show --format=%aD | head -1)" git tag -a v1.2 -m "v1.2"

Create an array with random values

Since the range of numbers is constrained, I'd say the best thing to do is generate the array, fill it with numbers zero through 39 (in order), then shuffle it.

Bootstrap 3 scrollable div for table

You can use too

style="overflow-y: scroll; height:150px; width: auto;"

It's works for me

What is the SSIS package and what does it do?

For Latest Info About SSIS > https://docs.microsoft.com/en-us/sql/integration-services/sql-server-integration-services

From the above referenced site:

Microsoft Integration Services is a platform for building enterprise-level data integration and data transformations solutions. Use Integration Services to solve complex business problems by copying or downloading files, loading data warehouses, cleansing and mining data, and managing SQL Server objects and data.

Integration Services can extract and transform data from a wide variety of sources such as XML data files, flat files, and relational data sources, and then load the data into one or more destinations.

Integration Services includes a rich set of built-in tasks and transformations, graphical tools for building packages, and the Integration Services Catalog database, where you store, run, and manage packages.

You can use the graphical Integration Services tools to create solutions without writing a single line of code. You can also program the extensive Integration Services object model to create packages programmatically and code custom tasks and other package objects.

Getting Started with SSIS - http://msdn.microsoft.com/en-us/sqlserver/bb671393.aspx

If you are Integration Services Information Worker - http://msdn.microsoft.com/en-us/library/ms141667.aspx

If you are Integration Services Administrator - http://msdn.microsoft.com/en-us/library/ms137815.aspx

If you are Integration Services Developer - http://msdn.microsoft.com/en-us/library/ms137709.aspx

If you are Integration Services Architect - http://msdn.microsoft.com/en-us/library/ms142161.aspx

Overview of SSIS - http://msdn.microsoft.com/en-us/library/ms141263.aspx

Integration Services How-to Topics - http://msdn.microsoft.com/en-us/library/ms141767.aspx

Install .ipa to iPad with or without iTunes

If you built the IPA using PhoneGap Build online you can download and install the IPA directly on your Ipad/Iphone by opening build.phonegap.com in Safari on the device, logging in and then clicking the iOS tab (the download ipa button). You will then be asked to install the app you built.

Direct link to this after logging in is: https://build.phonegap.com/apps/YOUR-BUILD-NUMBER/download/ios

What are best practices for multi-language database design?

I'm using next approach:

Product

ProductID OrderID,...

ProductInfo

ProductID Title Name LanguageID

Language

LanguageID Name Culture,....

Convert a list to a string in C#

This method helped me when trying to retrieve data from Text File and store it in Array then Assign it to a string avariable.

string[] lines = File.ReadAllLines(Environment.CurrentDirectory + "\\Notes.txt");  
string marRes = string.Join(Environment.NewLine, lines.ToArray());

Hopefully may help Someone!!!!

How to group an array of objects by key

Building on the answer by @Jonas_Wilms if you do not want to type in all your fields:

    var result = {};

    for ( let { first_field, ...fields } of your_data ) 
    { 
       result[first_field] = result[first_field] || [];
       result[first_field].push({ ...fields }); 
    }

I didn't make any benchmark but I believe using a for loop would be more efficient than anything suggested in this answer as well.

Running Command Line in Java

Process p = Runtime.getRuntime().exec("java -jar map.jar time.rel test.txt debug");

Error during SSL Handshake with remote server

I have 2 servers setup on docker, reverse proxy & web server. This error started happening for all my websites all of a sudden after 1 year. When setting up earlier, I generated a self signed certificate on the web server.

So, I had to generate the SSL certificate again and it started working...

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ssl.key -out ssl.crt

Convert string to number and add one

var first_value = '2';
// convert this string value into int
parseInt(first_value);

How to find all occurrences of a substring?

The pythonic way would be:

mystring = 'Hello World, this should work!'
find_all = lambda c,s: [x for x in range(c.find(s), len(c)) if c[x] == s]

# s represents the search string
# c represents the character string

find_all(mystring,'o')    # will return all positions of 'o'

[4, 7, 20, 26] 
>>> 

When running UPDATE ... datetime = NOW(); will all rows updated have the same date/time?

http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_now

"NOW() returns a constant time that indicates the time at which the statement began to execute. (Within a stored routine or trigger, NOW() returns the time at which the routine or triggering statement began to execute.) This differs from the behavior for SYSDATE(), which returns the exact time at which it executes as of MySQL 5.0.13. "

PG COPY error: invalid input syntax for integer

I think it's better to change your csv file like:

"age","first_name","last_name"
23,Ivan,Poupkine
,Eugene,Pirogov

It's also possible to define your table like

CREATE TABLE people (
  age        varchar(20),
  first_name varchar(20),
  last_name  varchar(20)
);

and after copy, you can convert empty strings:

select nullif(age, '')::int as age, first_name, last_name
from people

'sudo gem install' or 'gem install' and gem locations

Contrary to all the other posts I suggest NOT using sudo when installing gems.

Instead I recommend you install RVM and start a happy life with portable gem homes and different version of Ruby all living under one roof.

For the uninitiated, from the documentation:

RVM is a command line tool which allows us to easily install, manage and work with multiple ruby environments and sets of gems.

The reason why installing gems with sudo is worse than just gem install is because it installs the gems for ALL USERS as root. This might be fine if you're the only person using the machine, but if you're not it can cause weirdness.

If you decide you want to blow away all your gems and start again it's much easier, and safer, to do so as a non-root user.

If you decide you want to use RVM then using sudo will cause all kinds of weirdness because each Ruby version you install through RVM has its own GEM_HOME.

Also, it's nice if you can make your development environment as close to your production environment as possible, and in production you'll most likely install gems as a non-root user.

C# constructors overloading

Maybe your class isn't quite complete. Personally, I use a private init() function with all of my overloaded constructors.

class Point2D {

  double X, Y;

  public Point2D(double x, double y) {
    init(x, y);
  }

  public Point2D(Point2D point) {
    if (point == null)
      throw new ArgumentNullException("point");
    init(point.X, point.Y);
  }

  void init(double x, double y) {
    // ... Contracts ...
    X = x;
    Y = y;
  }
}

Regular expression for number with length of 4, 5 or 6

[0-9]{4,6} can be shortened to \d{4,6}

Link to "pin it" on pinterest without generating a button

If you want to create a simple hyperlink instead of the pin it button,

Change this:

http://pinterest.com/pin/create/button/?url=

To this:

http://pinterest.com/pin/create/link/?url=

So, a complete URL might simply look like this:

<a href="//pinterest.com/pin/create/link/?url=http%3A%2F%2Fwww.flickr.com%2Fphotos%2Fkentbrew%2F6851755809%2F&media=http%3A%2F%2Ffarm8.staticflickr.com%2F7027%2F6851755809_df5b2051c9_z.jpg&description=Next%20stop%3A%20Pinterest">Pin it</a>

jQuery delete confirmation box

Try this my friend

_x000D_
_x000D_
  // Confirmation Message On Delete Button._x000D_
_x000D_
  $('.close').click(function() {_x000D_
    return confirm('Are You Sure ?')_x000D_
  });
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<td class='close'></td>
_x000D_
_x000D_
_x000D_

Check object empty

You should check it against null.

If you want to check if object x is null or not, you can do:

    if(x != null)

But if it is not null, it can have properties which are null or empty. You will check those explicitly:

    if(x.getProperty() != null)

For "empty" check, it depends on what type is involved. For a Java String, you usually do:

    if(str != null && !str.isEmpty())

As you haven't mentioned about any specific problem with this, difficult to tell.

Is it possible to change the location of packages for NuGet?

None of this answers was working for me (Nuget 2.8.6) because of missing some tips, will try to add them here as it might be useful for others.

After reading the following sources:
https://docs.nuget.org/consume/NuGet-Config-Settings
https://github.com/NuGet/Home/issues/1346
It appears that

  1. To make working Install-Package properly with different repositoryPath you need to use forward slashes, it's because they are using Uri object to parse location.
  2. Without $ on the begining it was still ignoring my settings.
  3. NuGet caches config file, so after modifications you need to reload solution/VS.
  4. I had also strange issue while using command of NuGet.exe to set this option, as it modified my global NuGet.exe under AppData\Roaming\NuGet and started to restore packages there (Since that file has higher priority, just guessing).

E.g.

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <solution>
    <add key="disableSourceControlIntegration" value="true" />
  </solution>
  <config>
    <add key="repositorypath" value="$/../../../Common/packages" />
  </config>
</configuration>

You can also use NuGet command to ensure that syntax will be correct like this:

NuGet.exe config -Set repositoryPath=$/../../../Common/packages -ConfigFile NuGet.Config

password for postgres

What's the default superuser username/password for postgres after a new install?:

CAUTION The answer about changing the UNIX password for "postgres" through "$ sudo passwd postgres" is not preferred, and can even be DANGEROUS!

This is why: By default, the UNIX account "postgres" is locked, which means it cannot be logged in using a password. If you use "sudo passwd postgres", the account is immediately unlocked. Worse, if you set the password to something weak, like "postgres", then you are exposed to a great security danger. For example, there are a number of bots out there trying the username/password combo "postgres/postgres" to log into your UNIX system.

What you should do is follow Chris James's answer:

sudo -u postgres psql postgres

# \password postgres

Enter new password: 

To explain it a little bit...

C++ - Assigning null to a std::string

I can't assign a null to a String?

No. std::string is not a pointer type; it cannot be made "null." It cannot represent the absence of a value, which is what a null pointer is used to represent.

It can be made empty, by assigning an empty string to it (s = "" or s = std::string()) or by clearing it (s.clear()).

Use of Application.DoEvents()

The DoEvents does allow the user to click around or type and trigger other events, and background threads are a better approach.

However, there are still cases where you may run into issues that require flushing event messages. I ran into a problem where the RichTextBox control was ignoring the ScrollToCaret() method when the control had messages in queue to process.

The following code blocks all user input while executing DoEvents:

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace Integrative.Desktop.Common
{
    static class NativeMethods
    {
        #region Block input

        [DllImport("user32.dll", EntryPoint = "BlockInput")]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool BlockInput([MarshalAs(UnmanagedType.Bool)] bool fBlockIt);

        public static void HoldUser()
        {
            BlockInput(true);
        }

        public static void ReleaseUser()
        {
            BlockInput(false);
        }

        public static void DoEventsBlockingInput()
        {
            HoldUser();
            Application.DoEvents();
            ReleaseUser();
        }

        #endregion
    }
}

Oracle JDBC intermittent Connection Issue

A "connection reset" error message generally means that the other side has aborted the connection during the attempt to create a connection (the handshake). This has a lot of possible causes. A bug in the JDBC driver, a timeout at the DB side, a restart of the database, the DB being run out of available connections, poor network quality, bad virusscanner/firewall/proxy, etc.

As it happens intermittely, a bug in the JDBC driver can be less or more excluded. Left behind the remaining possible causes. I suggest to start with looking in the logs of the DB server.

How do I add images in laravel view?

You should store your images, css and JS files in a public directory. To create a link to any of them, use asset() helper:

{{ asset('img/myimage.png') }}

https://laravel.com/docs/5.1/helpers#method-asset

As alternative, you could use amazing Laravel Collective package for building forms and HTML elements, so your code will look like this:

{{ HTML::image('img/myimage.png', 'a picture') }}

Remove all padding and margin table HTML and CSS

Remove padding between cells inside the table. Just use cellpadding=0 and cellspacing=0 attributes in table tag.

Inline CSS styles in React: how to implement a:hover?

You can use css modules as an alternative, and additionally react-css-modules for class name mapping.

That way you can import your styles as follows and use normal css scoped locally to your components:

import React from 'react';
import CSSModules from 'react-css-modules';
import styles from './table.css';

class Table extends React.Component {
    render () {
        return <div styleName='table'>
            <div styleName='row'>
                <div styleName='cell'>A0</div>
                <div styleName='cell'>B0</div>
            </div>
        </div>;
    }
}

export default CSSModules(Table, styles);

Here is a webpack css modules example

jQuery Clone table row

Is very simple to clone the last row with jquery pressing a button:

Your Table HTML:

<table id="tableExample">
    <thead>
        <tr>
            <th>ID</th>
            <th>Header 1</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>1</td>
            <td>Line 1</td>
        </tr>
    </tbody>
    <tfoot>
        <tr>
            <td colspan="2"><button type="button" id="addRowButton">Add row</button></td>
        </tr>
    </tfoot>
</table>

JS:

$(document).on('click', '#addRowButton', function() {
    var table = $('#tableExample'),
        lastRow = table.find('tbody tr:last'),
        rowClone = lastRow.clone();

    table.find('tbody').append(rowClone);
});

Regards!

Remove the title bar in Windows Forms

Also add this bit of code to your form to allow it to be draggable still.

Just add it right before the constructor (the method that calls InitializeComponent()


private const int WM_NCHITTEST = 0x84;
private const int HTCLIENT = 0x1;
private const int HTCAPTION = 0x2;

///
/// Handling the window messages
///
protected override void WndProc(ref Message message)
{
    base.WndProc(ref message);

    if (message.Msg == WM_NCHITTEST && (int)message.Result == HTCLIENT)
        message.Result = (IntPtr)HTCAPTION;
}

That code is from: https://jachman.wordpress.com/2006/06/08/enhanced-drag-and-move-winforms-without-having-a-titlebar/

Now to get rid of the title bar but still have a border combine the code from the other response:

this.ControlBox = false;

this.Text = String.Empty;

with this line:

this.FormBorderStyle = FormBorderStyle.FixedSingle;


Put those 3 lines of code into the form's OnLoad event and you should have a nice 'floating' form that is draggable with a thin border (use FormBorderStyle.None if you want no border).

Error: "an object reference is required for the non-static field, method or property..."

You can't access non-static members from a static method. (Note that Main() is static, which is a requirement of .Net). Just make siprimo and volteado static, by placing the static keyword in front of them. e.g.:

 static private long volteado(long a)

SQL DELETE with JOIN another table for WHERE condition

Try this sample SQL scripts for easy understanding,

CREATE TABLE TABLE1 (REFNO VARCHAR(10))
CREATE TABLE TABLE2 (REFNO VARCHAR(10))

--TRUNCATE TABLE TABLE1
--TRUNCATE TABLE TABLE2

INSERT INTO TABLE1 SELECT 'TEST_NAME'
INSERT INTO TABLE1 SELECT 'KUMAR'
INSERT INTO TABLE1 SELECT 'SIVA'
INSERT INTO TABLE1 SELECT 'SUSHANT'

INSERT INTO TABLE2 SELECT 'KUMAR'
INSERT INTO TABLE2 SELECT 'SIVA'
INSERT INTO TABLE2 SELECT 'SUSHANT'

SELECT * FROM TABLE1
SELECT * FROM TABLE2

DELETE T1 FROM TABLE1 T1 JOIN TABLE2 T2 ON T1.REFNO = T2.REFNO

Your case is:

   DELETE pgc
     FROM guide_category pgc 
LEFT JOIN guide g
       ON g.id_guide = gc.id_guide 
    WHERE g.id_guide IS NULL

Python: finding lowest integer

list1 = [10,-4,5,2,33,4,7,8,2,3,5,8,99,-34]

print(list1)

max_v=list1[0]

min_v=list1[0]

for x in list1:
    if x>max_v:
        max_v=x
        print('X is {0} and max is {1}'.format(x,max_v))
for x in list1:
    if x<min_v:
        min_v=x
        print('X is {0} and min is {1}'.format(x,min_v))

print('Max values is ' + str(max_v))
print('Min values is ' + str(min_v))

How to master AngularJS?

For a comprehensive and continually growing collection of links check AngularJS-Learning, a github repo that collects resources, links and interesting blog posts.

I've found very helpful the tutorials and videos on the AngularJS youtube channel. They go from the mostly basic stuff to some advanced topics, a good way to start.

The official twitter and google+ accounts are a good way to follow news and get some nice links. Also check the AngularJS Mailing list.

A nice aggregator of news/link is angularjsdaily.com.

Also there're some new books out there, so you can keep an eye on your favourite online library.

Python matplotlib multiple bars

The trouble with using dates as x-values, is that if you want a bar chart like in your second picture, they are going to be wrong. You should either use a stacked bar chart (colours on top of each other) or group by date (a "fake" date on the x-axis, basically just grouping the data points).

import numpy as np
import matplotlib.pyplot as plt

N = 3
ind = np.arange(N)  # the x locations for the groups
width = 0.27       # the width of the bars

fig = plt.figure()
ax = fig.add_subplot(111)

yvals = [4, 9, 2]
rects1 = ax.bar(ind, yvals, width, color='r')
zvals = [1,2,3]
rects2 = ax.bar(ind+width, zvals, width, color='g')
kvals = [11,12,13]
rects3 = ax.bar(ind+width*2, kvals, width, color='b')

ax.set_ylabel('Scores')
ax.set_xticks(ind+width)
ax.set_xticklabels( ('2011-Jan-4', '2011-Jan-5', '2011-Jan-6') )
ax.legend( (rects1[0], rects2[0], rects3[0]), ('y', 'z', 'k') )

def autolabel(rects):
    for rect in rects:
        h = rect.get_height()
        ax.text(rect.get_x()+rect.get_width()/2., 1.05*h, '%d'%int(h),
                ha='center', va='bottom')

autolabel(rects1)
autolabel(rects2)
autolabel(rects3)

plt.show()

enter image description here

Get selected value/text from Select on change

No need for an onchange function. You can grab the value in one line:

document.getElementById("select_id").options[document.getElementById("select_id").selectedIndex].value;

Or, split it up for better readability:

var select_id = document.getElementById("select_id");

select_id.options[select_id.selectedIndex].value;

Conditionally hide CommandField or ButtonField in Gridview

it could be done when the RowDataBound event fires

  protected void GridView_RowDataBound(Object sender, GridViewRowEventArgs e)
  {
    if(e.Row.RowType == DataControlRowType.DataRow)
    {
      // Hide the edit button when some condition is true
      // for example, the row contains a certain property
      if (someCondition) 
      {
          Button btnEdit = (Button)e.Row.FindControl("btnEdit");

          btnEdit.Visible = false;
      }
    }   
  }

Here's a demo page

markup

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="DropDownDemo._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>GridView OnRowDataBound Example</title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
            <Columns>
                <asp:BoundField HeaderText="Name" DataField="name" />
                <asp:BoundField HeaderText="Age" DataField="age" />
                <asp:TemplateField>
                    <ItemTemplate>                
                        <asp:Button ID="BtnEdit" runat="server" Text="Edit" />
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </form>
</body>
</html>

Code Behind

using System;
using System.Collections.Generic;
using System.Web.UI.WebControls;

namespace GridViewDemo
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            GridView1.DataSource = GetCustomers();
            GridView1.DataBind();
        }

        protected override void OnInit(EventArgs e)
        {
            GridView1.RowDataBound += new GridViewRowEventHandler(GridView1_RowDataBound);
            base.OnInit(e);
        }

        void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType != DataControlRowType.DataRow) return;

            int age;
            if (int.TryParse(e.Row.Cells[1].Text, out age))
                if (age == 30)
                {
                    Button btnEdit = (Button) e.Row.FindControl("btnEdit");
                    btnEdit.Visible = false;
                }
        }

        private static List<Customer> GetCustomers()
        {
            List<Customer> results = new List<Customer>();

            results.Add(new Customer("Steve", 30));
            results.Add(new Customer("Brian", 40));
            results.Add(new Customer("Dave", 50));
            results.Add(new Customer("Bill", 25));
            results.Add(new Customer("Rich", 22));
            results.Add(new Customer("Bert", 30));

            return results;
        }
    }

    public class Customer
    {
        public string Name {get;set;}
        public int Age { get; set; }

        public Customer(string name, int age)
        {
            Name = name;
            Age = age;
        }
    }
}

In the demo, the Edit Button is not Visible (the HTML markup is not sent to the client) in those rows where the Customer's age is 30.

JQuery: detect change in input field

You can bind the 'input' event to the textbox. This would fire every time the input changes, so when you paste something (even with right click), delete and type anything.

$('#myTextbox').on('input', function() {
    // do something
});

If you use the change handler, this will only fire after the user deselects the input box, which may not be what you want.

There is an example of both here: http://jsfiddle.net/6bSX6/

How to convert decimal to hexadecimal in JavaScript

  • rgb(255, 255, 255) // returns FFFFFF

  • rgb(255, 255, 300) // returns FFFFFF

  • rgb(0,0,0) // returns 000000

  • rgb(148, 0, 211) // returns 9400D3

     function rgb(...values){
              return values.reduce((acc, cur) => {
                let val = cur >= 255 ? 'ff' : cur <= 0 ? '00' : Number(cur).toString(16);
                return acc + (val.length === 1 ? '0'+val : val);
              }, '').toUpperCase();
          }
    

setState() inside of componentDidUpdate()

this.setState creates an infinite loop when used in ComponentDidUpdate when there is no break condition in the loop. You can use redux to set a variable true in the if statement and then in the condition set the variable false then it will work.

Something like this.

if(this.props.route.params.resetFields){

        this.props.route.params.resetFields = false;
        this.setState({broadcastMembersCount: 0,isLinkAttached: false,attachedAffiliatedLink:false,affilatedText: 'add your affiliate link'});
        this.resetSelectedContactAndGroups();
        this.hideNext = false;
        this.initialValue_1 = 140;
        this.initialValue_2 = 140;
        this.height = 20
    }

How do I make Git use the editor of my choice for commits?

Atom as your git editor

git config --global core.editor "atom --wait"

Atom needs to be configured to run from the command line for the above to work:

OS X: install shell commands from Atom: menu bar > Atom > Install Shell Commands

Windows: no action required - atom is configured to run from the command line by default

C library function to perform sort

There are several C sorting functions available in stdlib.h. You can do man 3 qsort on a unix machine to get a listing of them but they include:

  • heapsort
  • quicksort
  • mergesort

JQuery .each() backwards

$($("li").get().reverse()).each(function() { /* ... */ });

Select DISTINCT individual columns in django?

User order by with that field, and then do distinct.

ProductOrder.objects.order_by('category').values_list('category', flat=True).distinct()

How do I represent a time only value in .NET?

You can use timespan

TimeSpan timeSpan = new TimeSpan(2, 14, 18);
Console.WriteLine(timeSpan.ToString());     // Displays "02:14:18".

[Edit]
Considering the other answers and the edit to the question, I would still use TimeSpan. No point in creating a new structure where an existing one from the framework suffice.
On these lines you would end up duplicating many native data types.

How to calculate probability in a normal distribution given mean & standard deviation?

I wrote this program to do the math for you. Just enter in the summary statistics. No need to provide an array:

One-Sample Z-Test for a Population Proportion:

To do this for mean rather than proportion, change the formula for z accordingly

EDIT:
Here is the content from the link:

import scipy.stats as stats
import math

def one_sample_ztest_pop_proportion(tail, p, pbar, n, alpha):
    #Calculate test stat

    sigma = math.sqrt((p*(1-p))/(n))
    z = round((pbar - p) / sigma, 2)

    if tail == 'lower':
        pval = round(stats.norm(p, sigma).cdf(pbar),4)
        print("Results for a lower tailed z-test: ")


    elif tail == 'upper':
        pval = round(1 - stats.norm(p, sigma).cdf(pbar),4)
        print("Results for an upper tailed z-test: ")


    elif tail == 'two':
        pval = round(stats.norm(p, sigma).cdf(pbar)*2,4)
        print("Results for a two tailed z-test: ")


    #Print test results
    print("Test statistic = {}".format(z))   
    print("P-value = {}".format(pval))
    print("Confidence = {}".format(alpha))

    #Compare p-value to confidence level
    if pval <= alpha:
        print("{} <=  {}. Reject the null hypothesis.".format(pval, alpha))
    else:
        print("{} > {}. Do not reject the null hypothesis.".format(pval, alpha))


#one_sample_ztest_pop_proportion('upper', .20, .25, 400, .05)

#one_sample_ztest_pop_proportion('two', .64, .52, 100, .05)

How to insert values in two dimensional array programmatically?

Think about it as array of array.

If you do this str[x][y], then there is array of length x where each element in turn contains array of length y. In java its not necessary for second dimension to have same length. So for x=i you can have y=m and x=j you can have y=n

For this your declaration looks like

String[][] test = new String[4][]; test[0] = new String[3]; test[1] = new String[2];

etc..

Exporting the values in List to excel

The most straightforward way (in my opinion) would be to simply put together a CSV file. If you want to get into formatting and actually writing to a *.xlsx file, there are more complicated solutions (and APIs) to do that for you.

Parse JSON from JQuery.ajax success data

I recommend you use:

var returnedData = JSON.parse(response);

to convert the JSON string (if it is just text) to a JavaScript object.

Setting JDK in Eclipse

Some additional steps may be needed to set both the project and default workspace JRE correctly, as MayoMan mentioned. Here is the complete sequence in Eclipse Luna:

  • Right click your project > properties
  • Select “Java Build Path” on left, then “JRE System Library”, click Edit…
  • Select "Workspace Default JRE"
  • Click "Installed JREs"
  • If you see JRE you want in the list select it (selecting a JDK is OK too)
  • If not, click Search…, navigate to Computer > Windows C: > Program Files > Java, then click OK
  • Now you should see all installed JREs, select the one you want
  • Click OK/Finish a million times

Easy.... not.

What does 'useLegacyV2RuntimeActivationPolicy' do in the .NET 4 config?

Here's an explanation I wrote recently to help with the void of information on this attribute. http://www.marklio.com/marklio/PermaLink,guid,ecc34c3c-be44-4422-86b7-900900e451f9.aspx (Internet Archive Wayback Machine link)

To quote the most relevant bits:

[Installing .NET] v4 is “non-impactful”. It should not change the behavior of existing components when installed.

The useLegacyV2RuntimeActivationPolicy attribute basically lets you say, “I have some dependencies on the legacy shim APIs. Please make them work the way they used to with respect to the chosen runtime.”

Why don’t we make this the default behavior? You might argue that this behavior is more compatible, and makes porting code from previous versions much easier. If you’ll recall, this can’t be the default behavior because it would make installation of v4 impactful, which can break existing apps installed on your machine.

The full post explains this in more detail. At RTM, the MSDN docs on this should be better.

Moment JS start and end of given month

your startDate is first-day-of-month, In this case we can use

var endDate = moment(startDate).add(1, 'months').subtract(1, 'days');

Hope this helps!!

How to send an email with Python?

Here is an example on Python 3.x, much simpler than 2.x:

import smtplib
from email.message import EmailMessage
def send_mail(to_email, subject, message, server='smtp.example.cn',
              from_email='[email protected]'):
    # import smtplib
    msg = EmailMessage()
    msg['Subject'] = subject
    msg['From'] = from_email
    msg['To'] = ', '.join(to_email)
    msg.set_content(message)
    print(msg)
    server = smtplib.SMTP(server)
    server.set_debuglevel(1)
    server.login(from_email, 'password')  # user & password
    server.send_message(msg)
    server.quit()
    print('successfully sent the mail.')

call this function:

send_mail(to_email=['[email protected]', '[email protected]'],
          subject='hello', message='Your analysis has done!')

below may only for Chinese user:

If you use 126/163, ????, you need to set"???????", like below:

enter image description here

ref: https://stackoverflow.com/a/41470149/2803344 https://docs.python.org/3/library/email.examples.html#email-examples

How to create an empty R vector to add new items

As pointed out by Brani, vector() is a solution, e.g.

newVector <- vector(mode = "numeric", length = 50)

will return a vector named "newVector" with 50 "0"'s as initial values. It is also fairly common to just add the new scalar to an existing vector to arrive at an expanded vector, e.g.

aVector <- c(aVector, newScalar)

Solution for "Fatal error: Maximum function nesting level of '100' reached, aborting!" in PHP

Another solution if you are running php script in CLI(cmd)

The php.ini file that needs edit is different in this case. In my WAMP installation the php.ini file that is loaded in command line is:

\wamp\bin\php\php5.5.12\php.ini

instead of \wamp\bin\apache\apache2.4.9\bin\php.ini which loads when php is run from browser

How to remove and clear all localStorage data

Something like this should do:

function cleanLocalStorage() {
    for(key in localStorage) {
        delete localStorage[key];
    }
}

Be careful about using this, though, as the user may have other data stored in localStorage and would probably be pretty ticked if you deleted that. I'd recommend either a) not storing the user's data in localStorage or b) storing the user's account stuff in a single variable, and then clearing that instead of deleting all the keys in localStorage.


Edit: As Lyn pointed out, you'll be good with localStorage.clear(). My previous points still stand, however.

Download a div in a HTML page as pdf using javascript

AFAIK there is no native jquery function that does this. Best option would be to process the conversion on the server. How you do this depends on what language you are using (.net, php etc.). You can pass the content of the div to the function that handles the conversion, which would return a pdf to the user.

How to analyze disk usage of a Docker container

After 1.13.0, Docker includes a new command docker system df to show docker disk usage.

$ docker system df
TYPE            TOTAL        ACTIVE     SIZE        RECLAIMABLE
Images          5            1          2.777 GB    2.647 GB (95%)
Containers      1            1          0 B         0B
Local Volumes   4            1          3.207 GB    2.261 (70%)

To show more detailed information on space usage:

$ docker system df --verbose

How to download a folder from github?

You can use Github Contents API to get an archive link and tar to retrieve a specified folder.

Command line:

curl https://codeload.github.com/[owner]/[repo]/tar.gz/master | \ tar -xz --strip=2 [repo]-master/[folder_path]


For example,
if you want to download examples/with-apollo/ folder from zeit/next.js, you can type this:

curl https://codeload.github.com/zeit/next.js/tar.gz/master | \
  tar -xz --strip=2 next.js-master/examples/with-apollo

Convert hex string to int

//Method for Smaller Number Range:
Integer.parseInt("abc",16);

//Method for Bigger Number Range.
Long.parseLong("abc",16);

//Method for Biggest Number Range.
new BigInteger("abc",16);

NPM stuck giving the same error EISDIR: Illegal operation on a directory, read at error (native)

I fixed this issue by moving my directory from my exFAT drive which does not support symlinking.

My exFat drive is shared between osx and a bootcamp windows partition so when I tried to clone and npm install my project it was failing but never explains that exFAT doesn't support this functionality.

There are drivers out there that you can install to add the ability to symlink but you'll have to do a lot of your setup manually compared to running a simple npm script.

"unable to locate adb" using Android Studio

I use android studio in Windows 7 and i have AVG for antivirus. The first time you launch adb, AVG prompts you to add avg.exe in antivirus vault. If you accept, then you android studio dont have access to run adb.exe. So open avg >> options >> Virus Vault >> Restore (select the adb file)

How to find the index of an element in an int array?

Binary search: Binary search can also be used to find the index of the array element in an array. But the binary search can only be used if the array is sorted. Java provides us with an inbuilt function which can be found in the Arrays library of Java which will rreturn the index if the element is present, else it returns -1. The complexity will be O(log n). Below is the implementation of Binary search.

public static int findIndex(int arr[], int t) { 
   int index = Arrays.binarySearch(arr, t); 
   return (index < 0) ? -1 : index; 
} 

how to count length of the JSON array element

First if the object you're dealing with is a string then you need to parse it then figure out the length of the keys :

obj = JSON.parse(jsonString);
shareInfoLen = Object.keys(obj.shareInfo[0]).length;

Trim Cells using VBA in Excel

I would try to solve this without VBA. Just select this space and use replace (change to nothing) on that worksheet you're trying to get rid off those spaces.

If you really want to use VBA I believe you could select first character

strSpace = left(range("A1").Value,1)

and use replace function in VBA the same way

Range("A1").Value = Replace(Range("A1").Value, strSpace, "")

or

for each cell in selection.cells
 cell.value = replace(cell.value, strSpace, "")
next

How to convert list to string

By using ''.join

list1 = ['1', '2', '3']
str1 = ''.join(list1)

Or if the list is of integers, convert the elements before joining them.

list1 = [1, 2, 3]
str1 = ''.join(str(e) for e in list1)

Adding item to Dictionary within loop

In your current code, what Dictionary.update() does is that it updates (update means the value is overwritten from the value for same key in passed in dictionary) the keys in current dictionary with the values from the dictionary passed in as the parameter to it (adding any new key:value pairs if existing) . A single flat dictionary does not satisfy your requirement , you either need a list of dictionaries or a dictionary with nested dictionaries.

If you want a list of dictionaries (where each element in the list would be a diciotnary of a entry) then you can make case_list as a list and then append case to it (instead of update) .

Example -

case_list = []
for entry in entries_list:
    case = {'key1': entry[0], 'key2': entry[1], 'key3':entry[2] }
    case_list.append(case)

Or you can also have a dictionary of dictionaries with the key of each element in the dictionary being entry1 or entry2 , etc and the value being the corresponding dictionary for that entry.

case_list = {}
for entry in entries_list:
    case = {'key1': value, 'key2': value, 'key3':value }
    case_list[entryname] = case  #you will need to come up with the logic to get the entryname.

Conversion failed when converting the varchar value to data type int in sql

The problem located on the following line

SELECT  @Prefix + LEN(CAST(@maxCode AS VARCHAR(10))+1) + CAST(@maxCode AS VARCHAR(100))

Use this instead

SELECT  @Prefix + CAST(LEN(CAST(@maxCode AS VARCHAR(10))+1) AS VARCHAR(100)) + CAST(@maxCode AS VARCHAR(100))

Full Code:

CREATE PROC [dbo].[getVoucherNo]

AS

BEGIN

    DECLARE @Prefix VARCHAR(10)='J'

    DECLARE @startFrom INT=1

    DECLARE @maxCode VARCHAR(100)

    DECLARE @sCode INT

    IF((SELECT COUNT(*) FROM dbo.Journal_Entry) > 0)
    BEGIN
        SELECT @maxCode = CAST(MAX(CAST(SUBSTRING(VoucharNo,LEN(@startFrom)+1,LEN(VoucharNo)- LEN(@Prefix)) AS INT))+1 AS varchar(100)) FROM dbo.Journal_Entry;
        SET @sCode=CAST(@maxCode AS INT)
        SELECT  @Prefix + CAST(LEN(CAST(@maxCode AS VARCHAR(10))+1) AS VARCHAR(100)) + CAST(@maxCode AS VARCHAR(100))
    END
    ELSE
    BEGIN
        SELECT(@Prefix + CAST(@startFrom AS VARCHAR)) 
    END
END

Selecting multiple items in ListView

In listView you can use it by Adapter

ArrayAdapter<String> adapterChannels = new ArrayAdapter<>(this, android.R.layout.simple_list_item_multiple_choice);

INSERT INTO vs SELECT INTO

Select into creates new table for you at the time and then insert records in it from the source table. The newly created table has the same structure as of the source table.If you try to use select into for a existing table it will produce a error, because it will try to create new table with the same name. Insert into requires the table to be exist in your database before you insert rows in it.

Get unique values from arraylist in java

You should use a Set. A Set is a Collection that contains no duplicates.

If you have a List that contains duplicates, you can get the unique entries like this:

List<String> gasList = // create list with duplicates...
Set<String> uniqueGas = new HashSet<String>(gasList);
System.out.println("Unique gas count: " + uniqueGas.size());

NOTE: This HashSet constructor identifies duplicates by invoking the elements' equals() methods.

How to generate an MD5 file hash in JavaScript?

You could use crypto-js.

I would also recommend using SHA256, rather than MD5.

To install crypto-js via NPM:

npm install crypto-js

Alternatively you can use a CDN and reference the JS file.

Then to display a MD5 and SHA256 hash, you can do the following:

<script type="text/javascript">
    var md5Hash = CryptoJS.MD5("Test");
    var sha256Hash = CryptoJS.SHA256("Test1");

    console.log(md5Hash.toString());
    console.log(sha256Hash.toString());
</script>

Working example located here, JSFiddle

There are also other JS functions that will generate an MD5 hash, outlined below.

http://www.myersdaily.org/joseph/javascript/md5-text.html

http://pajhome.org.uk/crypt/md5/md5.html

function md5cycle(x, k) {
var a = x[0], b = x[1], c = x[2], d = x[3];

a = ff(a, b, c, d, k[0], 7, -680876936);
d = ff(d, a, b, c, k[1], 12, -389564586);
c = ff(c, d, a, b, k[2], 17,  606105819);
b = ff(b, c, d, a, k[3], 22, -1044525330);
a = ff(a, b, c, d, k[4], 7, -176418897);
d = ff(d, a, b, c, k[5], 12,  1200080426);
c = ff(c, d, a, b, k[6], 17, -1473231341);
b = ff(b, c, d, a, k[7], 22, -45705983);
a = ff(a, b, c, d, k[8], 7,  1770035416);
d = ff(d, a, b, c, k[9], 12, -1958414417);
c = ff(c, d, a, b, k[10], 17, -42063);
b = ff(b, c, d, a, k[11], 22, -1990404162);
a = ff(a, b, c, d, k[12], 7,  1804603682);
d = ff(d, a, b, c, k[13], 12, -40341101);
c = ff(c, d, a, b, k[14], 17, -1502002290);
b = ff(b, c, d, a, k[15], 22,  1236535329);

a = gg(a, b, c, d, k[1], 5, -165796510);
d = gg(d, a, b, c, k[6], 9, -1069501632);
c = gg(c, d, a, b, k[11], 14,  643717713);
b = gg(b, c, d, a, k[0], 20, -373897302);
a = gg(a, b, c, d, k[5], 5, -701558691);
d = gg(d, a, b, c, k[10], 9,  38016083);
c = gg(c, d, a, b, k[15], 14, -660478335);
b = gg(b, c, d, a, k[4], 20, -405537848);
a = gg(a, b, c, d, k[9], 5,  568446438);
d = gg(d, a, b, c, k[14], 9, -1019803690);
c = gg(c, d, a, b, k[3], 14, -187363961);
b = gg(b, c, d, a, k[8], 20,  1163531501);
a = gg(a, b, c, d, k[13], 5, -1444681467);
d = gg(d, a, b, c, k[2], 9, -51403784);
c = gg(c, d, a, b, k[7], 14,  1735328473);
b = gg(b, c, d, a, k[12], 20, -1926607734);

a = hh(a, b, c, d, k[5], 4, -378558);
d = hh(d, a, b, c, k[8], 11, -2022574463);
c = hh(c, d, a, b, k[11], 16,  1839030562);
b = hh(b, c, d, a, k[14], 23, -35309556);
a = hh(a, b, c, d, k[1], 4, -1530992060);
d = hh(d, a, b, c, k[4], 11,  1272893353);
c = hh(c, d, a, b, k[7], 16, -155497632);
b = hh(b, c, d, a, k[10], 23, -1094730640);
a = hh(a, b, c, d, k[13], 4,  681279174);
d = hh(d, a, b, c, k[0], 11, -358537222);
c = hh(c, d, a, b, k[3], 16, -722521979);
b = hh(b, c, d, a, k[6], 23,  76029189);
a = hh(a, b, c, d, k[9], 4, -640364487);
d = hh(d, a, b, c, k[12], 11, -421815835);
c = hh(c, d, a, b, k[15], 16,  530742520);
b = hh(b, c, d, a, k[2], 23, -995338651);

a = ii(a, b, c, d, k[0], 6, -198630844);
d = ii(d, a, b, c, k[7], 10,  1126891415);
c = ii(c, d, a, b, k[14], 15, -1416354905);
b = ii(b, c, d, a, k[5], 21, -57434055);
a = ii(a, b, c, d, k[12], 6,  1700485571);
d = ii(d, a, b, c, k[3], 10, -1894986606);
c = ii(c, d, a, b, k[10], 15, -1051523);
b = ii(b, c, d, a, k[1], 21, -2054922799);
a = ii(a, b, c, d, k[8], 6,  1873313359);
d = ii(d, a, b, c, k[15], 10, -30611744);
c = ii(c, d, a, b, k[6], 15, -1560198380);
b = ii(b, c, d, a, k[13], 21,  1309151649);
a = ii(a, b, c, d, k[4], 6, -145523070);
d = ii(d, a, b, c, k[11], 10, -1120210379);
c = ii(c, d, a, b, k[2], 15,  718787259);
b = ii(b, c, d, a, k[9], 21, -343485551);

x[0] = add32(a, x[0]);
x[1] = add32(b, x[1]);
x[2] = add32(c, x[2]);
x[3] = add32(d, x[3]);

}

function cmn(q, a, b, x, s, t) {
a = add32(add32(a, q), add32(x, t));
return add32((a << s) | (a >>> (32 - s)), b);
}

function ff(a, b, c, d, x, s, t) {
return cmn((b & c) | ((~b) & d), a, b, x, s, t);
}

function gg(a, b, c, d, x, s, t) {
return cmn((b & d) | (c & (~d)), a, b, x, s, t);
}

function hh(a, b, c, d, x, s, t) {
return cmn(b ^ c ^ d, a, b, x, s, t);
}

function ii(a, b, c, d, x, s, t) {
return cmn(c ^ (b | (~d)), a, b, x, s, t);
}

function md51(s) {
txt = '';
var n = s.length,
state = [1732584193, -271733879, -1732584194, 271733878], i;
for (i=64; i<=s.length; i+=64) {
md5cycle(state, md5blk(s.substring(i-64, i)));
}
s = s.substring(i-64);
var tail = [0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0];
for (i=0; i<s.length; i++)
tail[i>>2] |= s.charCodeAt(i) << ((i%4) << 3);
tail[i>>2] |= 0x80 << ((i%4) << 3);
if (i > 55) {
md5cycle(state, tail);
for (i=0; i<16; i++) tail[i] = 0;
}
tail[14] = n*8;
md5cycle(state, tail);
return state;
}

/* there needs to be support for Unicode here,
 * unless we pretend that we can redefine the MD-5
 * algorithm for multi-byte characters (perhaps
 * by adding every four 16-bit characters and
 * shortening the sum to 32 bits). Otherwise
 * I suggest performing MD-5 as if every character
 * was two bytes--e.g., 0040 0025 = @%--but then
 * how will an ordinary MD-5 sum be matched?
 * There is no way to standardize text to something
 * like UTF-8 before transformation; speed cost is
 * utterly prohibitive. The JavaScript standard
 * itself needs to look at this: it should start
 * providing access to strings as preformed UTF-8
 * 8-bit unsigned value arrays.
 */
function md5blk(s) { /* I figured global was faster.   */
var md5blks = [], i; /* Andy King said do it this way. */
for (i=0; i<64; i+=4) {
md5blks[i>>2] = s.charCodeAt(i)
+ (s.charCodeAt(i+1) << 8)
+ (s.charCodeAt(i+2) << 16)
+ (s.charCodeAt(i+3) << 24);
}
return md5blks;
}

var hex_chr = '0123456789abcdef'.split('');

function rhex(n)
{
var s='', j=0;
for(; j<4; j++)
s += hex_chr[(n >> (j * 8 + 4)) & 0x0F]
+ hex_chr[(n >> (j * 8)) & 0x0F];
return s;
}

function hex(x) {
for (var i=0; i<x.length; i++)
x[i] = rhex(x[i]);
return x.join('');
}

function md5(s) {
return hex(md51(s));
}

/* this function is much faster,
so if possible we use it. Some IEs
are the only ones I know of that
need the idiotic second function,
generated by an if clause.  */

function add32(a, b) {
return (a + b) & 0xFFFFFFFF;
}

if (md5('hello') != '5d41402abc4b2a76b9719d911017c592') {
function add32(x, y) {
var lsw = (x & 0xFFFF) + (y & 0xFFFF),
msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}
}

Then simply use the MD5 function, as shown below:

alert(md5("Test string"));

Another working JS Fiddle here

How to schedule a stored procedure in MySQL

I used this query and it worked for me:

CREATE EVENT `exec`
  ON SCHEDULE EVERY 5 SECOND
  STARTS '2013-02-10 00:00:00'
  ENDS '2015-02-28 00:00:00'
  ON COMPLETION NOT PRESERVE ENABLE
DO 
  call delete_rows_links();

Get the difference between dates in terms of weeks, months, quarters, and years

Here the still lacking lubridate answer (although Gregor's function is built on this package)

The lubridate timespan documentation is very helpful for understanding the difference between periods and duration. I also like the lubridate cheatsheet and this very useful thread

library(lubridate)

dates <- c(dmy('14.01.2013'), dmy('26.03.2014'))

span <- dates[1] %--% dates[2] #creating an interval object

#creating period objects 
as.period(span, unit = 'year') 
#> [1] "1y 2m 12d 0H 0M 0S"
as.period(span, unit = 'month')
#> [1] "14m 12d 0H 0M 0S"
as.period(span, unit = 'day')
#> [1] "436d 0H 0M 0S"

Periods do not accept weeks as units. But you can convert durations to weeks:

as.duration(span)/ dweeks(1)
#makes duration object (in seconds) and divides by duration of a week (in seconds)
#> [1] 62.28571

Created on 2019-11-04 by the reprex package (v0.3.0)

What’s the best way to check if a file exists in C++? (cross platform)

NO REQUIRED, which would be an overkill.


Use stat() (not cross platform though as mentioned by pavon), like this:

#include <sys/stat.h>
#include <iostream>

// true if file exists
bool fileExists(const std::string& file) {
    struct stat buf;
    return (stat(file.c_str(), &buf) == 0);
}

int main() {
    if(!fileExists("test.txt")) {
        std::cerr << "test.txt doesn't exist, exiting...\n";
        return -1;
    }
    return 0;
}

Output:

C02QT2UBFVH6-lm:~ gsamaras$ ls test.txt
ls: test.txt: No such file or directory
C02QT2UBFVH6-lm:~ gsamaras$ g++ -Wall main.cpp
C02QT2UBFVH6-lm:~ gsamaras$ ./a.out
test.txt doesn't exist, exiting...

Another version (and that) can be found here.

How to use Git and Dropbox together?

I store my non-Github repo's on Dropbox. One caveat I ran into was syncing after a reinstall. Dropbox will download the smallest files first before moving to the larger ones. Not an issue if you start at night and come back after the weekend :-)

My thread - http://forums.dropbox.com/topic.php?id=29984&replies=6

error while loading shared libraries: libncurses.so.5:

Mixaz's above answer worked for me. However I had issues installing the package because of PGP check failures. Installing it by skipping the signature worked, you could try this :

yaourt --m-arg "--skipchecksums --skippgpcheck" -Sb <your-package>

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

You have to make a new instance of OrderedDict. If your keys are unique:

d1=OrderedDict([("a",1),("b",2)])
d2=OrderedDict([("c",3),("d",99)])
both=OrderedDict(list(d2.items()) + list(d1.items()))
print(both)

#OrderedDict([('c', 3), ('d', 99), ('a', 1), ('b', 2)])

But if not, beware as this behavior may or may not be desired for you:

d1=OrderedDict([("a",1),("b",2)])
d2=OrderedDict([("c",3),("b",99)])
both=OrderedDict(list(d2.items()) + list(d1.items()))
print(both)

#OrderedDict([('c', 3), ('b', 2), ('a', 1)])

What is the difference between a mutable and immutable string in C#?

String in C# is immutable. If you concatenate it with any string, you are actually making a new string, that is new string object ! But StringBuilder creates mutable string.

Getting "Lock wait timeout exceeded; try restarting transaction" even though I'm not using a transaction

You are using a transaction; autocommit does not disable transactions, it just makes them automatically commit at the end of the statement.

What is happening is, some other thread is holding a record lock on some record (you're updating every record in the table!) for too long, and your thread is being timed out.

You can see more details of the event by issuing a

SHOW ENGINE INNODB STATUS

after the event (in sql editor). Ideally do this on a quiet test-machine.

How to yum install Node.JS on Amazon Linux

As others mentioned using epel gives a really outdated version, here is a little script I just wrote instead to add to the CI pipeline or pass it to ec2 user-data to install the latest version of node, simply replace the version with what you want, and the appropriate distro of Linux you are using.

The following example is for amazon-Linux-2-AMI

#!/bin/bash

version='v14.13.1'
distro='linux-x64'
package_name="node-$version-$distro"
package_location="/usr/local/lib/"

curl -O https://nodejs.org/download/release/latest/$package_name.tar.gz
tar -xvf $package_name.tar.gz -C $package_location
rm -rfv $package_name.tar.gz

echo "export PATH=$package_location/$package_name/bin:\$PATH" >> ~/.profile

if you want to test it in the same shell simply run

. ~/.profile

How to import multiple .csv files at once?

As well as using lapply or some other looping construct in R you could merge your CSV files into one file.

In Unix, if the files had no headers, then its as easy as:

cat *.csv > all.csv

or if there are headers, and you can find a string that matches headers and only headers (ie suppose header lines all start with "Age"), you'd do:

cat *.csv | grep -v ^Age > all.csv

I think in Windows you could do this with COPY and SEARCH (or FIND or something) from the DOS command box, but why not install cygwin and get the power of the Unix command shell?

Could not load file or assembly ... An attempt was made to load a program with an incorrect format (System.BadImageFormatException)

I have detected something different from the other answers. Reaching this exception in my project was the result of a corrupt compilation. Without making any changes, just forcing rebuild, it was fixed.

What is causing the error `string.split is not a function`?

run this

// you'll see that it prints Object
console.log(typeof document.location);

you want document.location.toString() or document.location.href

ImportError: No module named PyQt4.QtCore

I had the "No module named PyQt4.QtCore" error and installing the python-qt4 package fixed it only partially: I could run

from PyQt4.QtCore import SIGNAL

from a python interpreter but only without activating my virtualenv.

The only solution I've found till now to use a virtualenv is to copy the PyQt4 folder and the sip.so file into my virtualenv as explained here: Is it possible to add PyQt4/PySide packages on a Virtualenv sandbox?

HTTP POST with Json on Body - Flutter/Dart

This works!

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'package:http/http.dart' as http;

Future<http.Response> postRequest () async {
  var url ='https://pae.ipportalegre.pt/testes2/wsjson/api/app/ws-authenticate';

  Map data = {
    'apikey': '12345678901234567890'
  }
  //encode Map to JSON
  var body = json.encode(data);

  var response = await http.post(url,
      headers: {"Content-Type": "application/json"},
      body: body
  );
  print("${response.statusCode}");
  print("${response.body}");
  return response;
}

Undefined symbols for architecture i386

Add the framework required for the method used in the project target in the "Link Binaries With Libraries" list of Build Phases, it will work easily. Like I have imported to my project

QuartzCore.framework

For the bug

Undefined symbols for architecture i386:

Activity restart on rotation Android

Using the Application Class

Depending on what you're doing in your initialization you could consider creating a new class that extends Application and moving your initialization code into an overridden onCreate method within that class.

public class MyApplicationClass extends Application {
  @Override
  public void onCreate() {
    super.onCreate();
    // TODO Put your application initialization code here.
  }
}

The onCreate in the application class is only called when the entire application is created, so the Activity restarts on orientation or keyboard visibility changes won't trigger it.

It's good practice to expose the instance of this class as a singleton and exposing the application variables you're initializing using getters and setters.

NOTE: You'll need to specify the name of your new Application class in the manifest for it to be registered and used:

<application
    android:name="com.you.yourapp.MyApplicationClass"

Reacting to Configuration Changes [UPDATE: this is deprecated since API 13; see the recommended alternative]

As a further alternative, you can have your application listen for events that would cause a restart – like orientation and keyboard visibility changes – and handle them within your Activity.

Start by adding the android:configChanges node to your Activity's manifest node

 <activity android:name=".MyActivity"
      android:configChanges="orientation|keyboardHidden"
      android:label="@string/app_name">

or for Android 3.2 (API level 13) and newer:

<activity android:name=".MyActivity"
      android:configChanges="keyboardHidden|orientation|screenSize"
      android:label="@string/app_name">

Then within the Activity override the onConfigurationChanged method and call setContentView to force the GUI layout to be re-done in the new orientation.

@Override
public void onConfigurationChanged(Configuration newConfig) {
  super.onConfigurationChanged(newConfig);
  setContentView(R.layout.myLayout);
}

How to use paths in tsconfig.json?

/ starts from the root only, to get the relative path we should use ./ or ../

How to only get file name with Linux 'find'?

I've found a solution (on makandracards page), that gives just the newest file name:

ls -1tr * | tail -1

(thanks goes to Arne Hartherz)

I used it for cp:

cp $(ls -1tr * | tail -1) /tmp/

How do I change tab size in Vim?

Expanding on zoul's answer:

If you want to setup Vim to use specific settings when editing a particular filetype, you'll want to use autocommands:

autocmd Filetype css setlocal tabstop=4

This will make it so that tabs are displayed as 4 spaces. Setting expandtab will cause Vim to actually insert spaces (the number of them being controlled by tabstop) when you press tab; you might want to use softtabstop to make backspace work properly (that is, reduce indentation when that's what would happen should tabs be used, rather than always delete one char at a time).

To make a fully educated decision as to how to set things up, you'll need to read Vim docs on tabstop, shiftwidth, softtabstop and expandtab. The most interesting bit is found under expandtab (:help 'expandtab):

There are four main ways to use tabs in Vim:

  1. Always keep 'tabstop' at 8, set 'softtabstop' and 'shiftwidth' to 4 (or 3 or whatever you prefer) and use 'noexpandtab'. Then Vim will use a mix of tabs and spaces, but typing and will behave like a tab appears every 4 (or 3) characters.

  2. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use 'expandtab'. This way you will always insert spaces. The formatting will never be messed up when 'tabstop' is changed.

  3. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use a |modeline| to set these values when editing the file again. Only works when using Vim to edit the file.

  4. Always set 'tabstop' and 'shiftwidth' to the same value, and 'noexpandtab'. This should then work (for initial indents only) for any tabstop setting that people use. It might be nice to have tabs after the first non-blank inserted as spaces if you do this though. Otherwise aligned comments will be wrong when 'tabstop' is changed.

How to disable and then enable onclick event on <div> with javascript

I'm confused by your question, seems to me that the question title and body are asking different things. If you want to disable/enable a click event on a div simply do:

$("#id").on('click', function(){ //enables click event
    //do your thing here
});

$("#id").off('click'); //disables click event

If you want to disable a div, use the following code:

$("#id").attr('disabled','disabled');

Hope this helps.

edit: oops, didn't see the other bind/unbind answer. Sorry. Those methods are also correct, though they've been deprecated in jQuery 1.7, and replaced by on()/off()

Real time face detection OpenCV, Python

Your line:

img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

will draw a rectangle in the image, but the return value will be None, so img changes to None and cannot be drawn.

Try

cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

How can I escape a double quote inside double quotes?

A simple example of escaping quotes in the shell:

$ echo 'abc'\''abc'
abc'abc
$ echo "abc"\""abc"
abc"abc

It's done by finishing an already-opened one ('), placing the escaped one (\'), and then opening another one (').

Alternatively:

$ echo 'abc'"'"'abc'
abc'abc
$ echo "abc"'"'"abc"
abc"abc

It's done by finishing already opened one ('), placing a quote in another quote ("'"), and then opening another one (').

More examples: Escaping single-quotes within single-quoted strings

How to use an existing database with an Android application

I had trouble with the other DatabaseHelpers regarding this problem, not sure why.
This is what worked for me:

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DatabaseHelper extends SQLiteOpenHelper {

  private static final String TAG = DatabaseHelper.class.getSimpleName();

  private final Context context;
  private final String assetPath;
  private final String dbPath;

  public DatabaseHelper(Context context, String dbName, String assetPath)
      throws IOException {
    super(context, dbName, null, 1);
    this.context = context;
    this.assetPath = assetPath;
    this.dbPath = "/data/data/"
        + context.getApplicationContext().getPackageName() + "/databases/"
        + dbName;
    checkExists();
  }

  /**
   * Checks if the database asset needs to be copied and if so copies it to the
   * default location.
   * 
   * @throws IOException
   */
  private void checkExists() throws IOException {
    Log.i(TAG, "checkExists()");

    File dbFile = new File(dbPath);

    if (!dbFile.exists()) {

      Log.i(TAG, "creating database..");

      dbFile.getParentFile().mkdirs();
      copyStream(context.getAssets().open(assetPath), new FileOutputStream(
          dbFile));

      Log.i(TAG, assetPath + " has been copied to " + dbFile.getAbsolutePath());
    }

  }

  private void copyStream(InputStream is, OutputStream os) throws IOException {
    byte buf[] = new byte[1024];
    int c = 0;
    while (true) {
      c = is.read(buf);
      if (c == -1)
        break;
      os.write(buf, 0, c);
    }
    is.close();
    os.close();
  }

  @Override
  public void onCreate(SQLiteDatabase db) {
  }

  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
  }
}

how to sort pandas dataframe from one column

Use sort_values to sort the df by a specific column's values:

In [18]:
df.sort_values('2')

Out[18]:
        0          1     2
4    85.6    January   1.0
3    95.5   February   2.0
7   104.8      March   3.0
0   354.7      April   4.0
8   283.5        May   5.0
6   238.7       June   6.0
5   152.0       July   7.0
1    55.4     August   8.0
11  212.7  September   9.0
10  249.6    October  10.0
9   278.8   November  11.0
2   176.5   December  12.0

If you want to sort by two columns, pass a list of column labels to sort_values with the column labels ordered according to sort priority. If you use df.sort_values(['2', '0']), the result would be sorted by column 2 then column 0. Granted, this does not really make sense for this example because each value in df['2'] is unique.

What is “assert” in JavaScript?

As mentioned by T.J., There is no assert in JavaScript. However, there is a node module named assert, which is used mostly for testing. so, you might see code like:

const assert = require('assert');
assert(5 > 7);

Executing multi-line statements in the one-line command-line?

single/double quotes and backslash everywhere:

$ python -c 'exec("import sys\nfor i in range(10): print \"bob\"")'

Much better:

$ python -c '
> import sys
> for i in range(10):
>   print "bob"
> '

Does "git fetch --tags" include "git fetch"?

Note: this answer is only valid for git v1.8 and older.

Most of this has been said in the other answers and comments, but here's a concise explanation:

  • git fetch fetches all branch heads (or all specified by the remote.fetch config option), all commits necessary for them, and all tags which are reachable from these branches. In most cases, all tags are reachable in this way.
  • git fetch --tags fetches all tags, all commits necessary for them. It will not update branch heads, even if they are reachable from the tags which were fetched.

Summary: If you really want to be totally up to date, using only fetch, you must do both.

It's also not "twice as slow" unless you mean in terms of typing on the command-line, in which case aliases solve your problem. There is essentially no overhead in making the two requests, since they are asking for different information.

How to change the cursor into a hand when a user hovers over a list item?

You can use the code below:

li:hover { cursor: pointer; }

XML parsing of a variable string in JavaScript

<script language="JavaScript">
function importXML()
{
    if (document.implementation && document.implementation.createDocument)
    {
            xmlDoc = document.implementation.createDocument("", "", null);
            xmlDoc.onload = createTable;
    }
    else if (window.ActiveXObject)
    {
            xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
            xmlDoc.onreadystatechange = function () {
                    if (xmlDoc.readyState == 4) createTable()
            };
    }
    else
    {
            alert('Your browser can\'t handle this script');
            return;
    }
    xmlDoc.load("emperors.xml");
}

function createTable()
{
    var theData="";
    var x = xmlDoc.getElementsByTagName('emperor');
    var newEl = document.createElement('TABLE');
    newEl.setAttribute('cellPadding',3);
    newEl.setAttribute('cellSpacing',0);
    newEl.setAttribute('border',1);
    var tmp = document.createElement('TBODY');
    newEl.appendChild(tmp);
    var row = document.createElement('TR');
    for (j=0;j<x[0].childNodes.length;j++)
    {
            if (x[0].childNodes[j].nodeType != 1) continue;
            var container = document.createElement('TH');
            theData = document.createTextNode(x[0].childNodes[j].nodeName);
            container.appendChild(theData);
            row.appendChild(container);
    }
    tmp.appendChild(row);
    for (i=0;i<x.length;i++)
    {
            var row = document.createElement('TR');
            for (j=0;j<x[i].childNodes.length;j++)
            {
                    if (x[i].childNodes[j].nodeType != 1) continue;
                    var container = document.createElement('TD');
                    var theData = document.createTextNode(x[i].childNodes[j].firstChild.nodeValue);
                    container.appendChild(theData);
                    row.appendChild(container);
            }
            tmp.appendChild(row);
    }
    document.getElementById('writeroot').appendChild(newEl);
}
</script>
</HEAD>

<BODY onLoad="javascript:importXML();">
<p id=writeroot> </p>
</BODY>

For more info refer this http://www.easycodingclub.com/xml-parser-in-javascript/javascript-tutorials/

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.

How to force table cell <td> content to wrap?

td {
overflow: hidden;
max-width: 400px;
word-wrap: break-word;
}

How to get to Model or Viewbag Variables in a Script Tag

Use single quotation marks ('):

var val = '@ViewBag.ForSection';
alert(val);

Centering floating divs within another div

In my case, I could not get the answer by @Sampson to work for me, at best I got a single column centered on the page. In the process however, I learned how the float actually works and created this solution. At it's core the fix is very simple but hard to find as evident by this thread which has had more than 146k views at the time of this post without mention.

All that is needed is to total the amount of screen space width that the desired layout will occupy then make the parent the same width and apply margin:auto. That's it!

The elements in the layout will dictate the width and height of the "outer" div. Take each "myFloat" or element's width or height + its borders + its margins and its paddings and add them all together. Then add the other elements together in the same fashion. This will give you the parent width. They can all be somewhat different sizes and you can do this with fewer or more elements.

Ex.(each element has 2 sides so border, margin and padding get multiplied x2)

So an element that has a width of 10px, border 2px, margin 6px, padding 3px would look like this: 10 + 4 + 12 + 6 = 32

Then add all of your element's totaled widths together.

Element 1 = 32
Element 2 = 24
Element 3 = 32
Element 4 = 24

In this example the width for the "outer" div would be 112.

_x000D_
_x000D_
.outer {_x000D_
  /* floats + margins + borders = 270 */_x000D_
  max-width: 270px;_x000D_
  margin: auto;_x000D_
  height: 80px;_x000D_
  border: 1px;_x000D_
  border-style: solid;_x000D_
}_x000D_
_x000D_
.myFloat {_x000D_
    /* 3 floats x 50px = 150px */_x000D_
    width: 50px;_x000D_
    /* 6 margins x 10px = 60 */_x000D_
    margin: 10px;_x000D_
    /* 6 borders x 10px = 60 */_x000D_
    border: 10px solid #6B6B6B;_x000D_
    float: left;_x000D_
    text-align: center;_x000D_
    height: 40px;_x000D_
}
_x000D_
<div class="outer">_x000D_
  <div class="myFloat">Float 1</div>_x000D_
  <div class="myFloat">Float 2</div>_x000D_
  <div class="myFloat">Float 3</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to fetch the dropdown values from database and display in jsp

You can learn some tutorials for JSP page direct access database (mysql) here

Notes:

  • import sql tag library in jsp page

    <%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql"%>

  • then set datasource on page

    <sql:setDataSource var="ds" driver="com.mysql.jdbc.Driver" url="jdbc:mysql://<yourhost>/<yourdb>" user="<user>" password="<password>"/>
    
  • Now query what you want on page

    <sql:query dataSource="${ds}" var="result"> //ref  defined 'ds'
        SELECT * from <your-table>;
    </sql:query>
    
  • Finally you can populate dropdowns on page using c:forEach tag to iterate result rows in select element

    <c:forEach var="row" items="${result.rows}"> //ref set var 'result' <option value='<c:out value="${row.key}"/>'><c:out value="${row.value}"/</option> </c:forEach>

Smart way to truncate long strings

Best function I have found. Credit to text-ellipsis.

function textEllipsis(str, maxLength, { side = "end", ellipsis = "..." } = {}) {
  if (str.length > maxLength) {
    switch (side) {
      case "start":
        return ellipsis + str.slice(-(maxLength - ellipsis.length));
      case "end":
      default:
        return str.slice(0, maxLength - ellipsis.length) + ellipsis;
    }
  }
  return str;
}

Examples:

var short = textEllipsis('a very long text', 10);
console.log(short);
// "a very ..."

var short = textEllipsis('a very long text', 10, { side: 'start' });
console.log(short);
// "...ng text"

var short = textEllipsis('a very long text', 10, { textEllipsis: ' END' });
console.log(short);
// "a very END"

Python interpreter error, x takes no arguments (1 given)

Python implicitly passes the object to method calls, but you need to explicitly declare the parameter for it. This is customarily named self:

def updateVelocity(self):

Android and Facebook share intent

    public void invokeShare(Activity activity, String quote, String credit) {
    Intent shareIntent = new Intent(android.content.Intent.ACTION_SEND);
    shareIntent.setType("text/plain");
    shareIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, activity.getString(R.string.share_subject));
    shareIntent.putExtra(android.content.Intent.EXTRA_TEXT, "Example text");    
    shareIntent.putExtra("com.facebook.platform.extra.APPLICATION_ID", activity.getString(R.string.app_id));                        
    activity.startActivity(Intent.createChooser(shareIntent, activity.getString(R.string.share_title)));
}

creating a random number using MYSQL

Additional to this answer, create a function like

CREATE FUNCTION myrandom(
    pmin INTEGER,
    pmax INTEGER
)
RETURNS INTEGER(11)
DETERMINISTIC
NO SQL
SQL SECURITY DEFINER
BEGIN
  RETURN floor(pmin+RAND()*(pmax-pmin));
END; 

and call like

SELECT myrandom(100,300);

This gives you random number between 100 and 300

How to compare two colors for similarity/difference

Kotlin version with how much percent do you want to match.

Method call with percent optional argument

isMatchingColor(intColor1, intColor2, 95) // should match color if 95% similar

Method body

private fun isMatchingColor(intColor1: Int, intColor2: Int, percent: Int = 90): Boolean {
    val threadSold = 255 - (255 / 100f * percent)

    val diffAlpha = abs(Color.alpha(intColor1) - Color.alpha(intColor2))
    val diffRed = abs(Color.red(intColor1) - Color.red(intColor2))
    val diffGreen = abs(Color.green(intColor1) - Color.green(intColor2))
    val diffBlue = abs(Color.blue(intColor1) - Color.blue(intColor2))

    if (diffAlpha > threadSold) {
        return false
    }

    if (diffRed > threadSold) {
        return false
    }

    if (diffGreen > threadSold) {
        return false
    }

    if (diffBlue > threadSold) {
        return false
    }

    return true
}

How to test an SQL Update statement before running it?

I know this is a repeat of other answers, but it has some emotional support to take the extra step for testing update :D

For testing update, hash # is your friend.

If you have an update statement like:

UPDATE 
wp_history
SET history_by="admin"
WHERE
history_ip LIKE '123%'

You hash UPDATE and SET out for testing, then hash them back in:

SELECT * FROM
#UPDATE
wp_history
#SET history_by="admin"
WHERE
history_ip LIKE '123%'

It works for simple statements.

An additional practically mandatory solution is, to get a copy (backup duplicate), whenever using update on a production table. Phpmyadmin > operations > copy: table_yearmonthday. It just takes a few seconds for tables <=100M.

Android setOnClickListener method - How does it work?

That what manual says about setOnClickListener method is:

public void setOnClickListener (View.OnClickListener l)

Added in API level 1 Register a callback to be invoked when this view is clicked. If this view is not clickable, it becomes clickable.

Parameters

l View.OnClickListener: The callback that will run

And normally you have to use it like this

public class ExampleActivity extends Activity implements OnClickListener {
    protected void onCreate(Bundle savedValues) {
        ...
        Button button = (Button)findViewById(R.id.corky);
        button.setOnClickListener(this);
    }

    // Implement the OnClickListener callback
    public void onClick(View v) {
      // do something when the button is clicked
    }
    ...
}

Take a look at this lesson as well Building a Simple Calculator using Android Studio.

How to insert data using wpdb

Use $wpdb->insert().

$wpdb->insert('wp_submitted_form', array(
    'name' => 'Kumkum',
    'email' => '[email protected]',
    'phone' => '3456734567', // ... and so on
));

Addition from @mastrianni:

$wpdb->insert sanitizes your data for you, unlike $wpdb->query which requires you to sanitize your query with $wpdb->prepare. The difference between the two is $wpdb->query allows you to write your own SQL statement, where $wpdb->insert accepts an array and takes care of sanitizing/sql for you.

Accessing last x characters of a string in Bash

1. Generalized Substring

To generalise the question and the answer of gniourf_gniourf (as this is what I was searching for), if you want to cut a range of characters from, say, 7th from the end to 3rd from the end, you can use this syntax:

${string: -7:4}

Where 4 is the length of course (7-3).

2. Alternative using cut

In addition, while the solution of gniourf_gniourf is obviously the best and neatest, I just wanted to add an alternative solution using cut:

echo $string | cut -c $((${#string}-2))-

Here, ${#string} is the length of the string, and the "-" means cut to the end.

3. Alternative using awk

This solution instead uses the substring function of awk to select a substring which has the syntax substr(string, start, length) going to the end if the length is omitted. length($string)-2) thus picks up the last three characters.

echo $string | awk '{print substr($1,length($1)-2) }'

Math functions in AngularJS bindings

If you're looking to do a simple round in Angular you can easily set the filter inside your expression. For example:

{{ val | number:0 }}

See this CodePen example & for other number filter options.

Angular Docs on using Number Filters

jQuery get selected option value (not the text, but the attribute 'value')

I just wanted to share my experience

For me,

$('#selectorId').val()

returned null.

I had to use

$('#selectorId option:selected').val()

How to remove foreign key constraint in sql server?

To remove all the constraints from the DB:

SELECT 'ALTER TABLE ' + Table_Name  +' DROP CONSTRAINT ' + Constraint_Name
FROM Information_Schema.CONSTRAINT_TABLE_USAGE

HTML code for an apostrophe

&#39; in decimal.

%27 in hex.

Hive insert query like SQL

You could definitely append data into an existing table. (But it is actually not an append at the HDFS level). It's just that whenever you do a LOAD or INSERT operation on an existing Hive table without OVERWRITE clause the new data will be put without replacing the old data. A new file will be created for this newly inserted data inside the directory corresponding to that table. For example :

I have a file named demo.txt which has 2 lines :

ABC
XYZ

Create a table and load this file into it

hive> create table demo(foo string);
hive> load data inpath '/demo.txt' into table demo;

Now,if I do a SELECT on this table it'll give me :

hive> select * from demo;                        
OK    
ABC    
XYZ

Suppose, I have one more file named demo2.txt which has :

PQR

And I do a LOAD again on this table without using overwrite,

hive> load data inpath '/demo2.txt' into table demo;

Now, if I do a SELECT now, it'll give me,

hive> select * from demo;                       
OK
ABC
XYZ
PQR

HTH

Cannot bulk load because the file could not be opened. Operating System Error Code 3

It's probably a permissions issue but you need to make sure to try these steps to troubleshoot:

  • Put the file on a local drive and see if the job works (you don't necessarily need RDP access if you can map a drive letter on your local workstation to a directory on the database server)
  • Put the file on a remote directory that doesn't require username and password (allows Everyone to read) and use the UNC path (\server\directory\file.csv)
  • Configure the SQL job to run as your own username
  • Configure the SQL job to run as sa and add the net use and net use /delete commands before and after

Remember to undo any changes (especially running as sa). If nothing else works, you can try to change the bulk load into a scheduled task, running on the database server or another server that has bcp installed.

Why I am getting Cannot pass parameter 2 by reference error when I am using bindParam with a constant value?

Try This.

$stmt->bindValue(':v1', null, PDO::PARAM_NULL); // --> insert null

How to set HTML Auto Indent format on Sublime Text 3?

One option is to type [command] + [shift] + [p] (or the equivalent) and then type 'indentation'. The top result should be 'Indendtation: Reindent Lines'. Press [enter] and it will format the document.

Another option is to install the Emmet plugin (http://emmet.io/), which will provide not only better formatting, but also a myriad of other incredible features. To get the output you're looking for using Sublime Text 3 with the Emmet plugin requires just the following:

p [tab][enter] Hello world!

When you type p [tab] Emmet expands it to:

<p></p>

Pressing [enter] then further expands it to:

<p>

</p>

With the cursor indented and on the line between the tags. Meaning that typing text results in:

<p>
    Hello, world!
</p>

What is the iOS 6 user agent string?

Some more:

Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_3 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10B329 Safari/8536.25

Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_4 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) Version/6.0 Mobile/10B350 Safari/8536.25

Split comma separated column data into additional columns

split_part() does what you want in one step:

SELECT split_part(col, ',', 1) AS col1
     , split_part(col, ',', 2) AS col2
     , split_part(col, ',', 3) AS col3
     , split_part(col, ',', 4) AS col4
FROM   tbl;

Add as many lines as you have items in col (the possible maximum). Columns exceeding data items will be empty strings ('').

PHP find difference between two datetimes

Sorry my previous answer was wrong. If you are trying to take total elapsed time between time and timeout in the format Y-m-d H:i:s format, take diff between timeout and time in using DateTime object and format it as '%y-%m-%d %H:%i:%s'.

What's the difference between subprocess Popen and call (how can I use them)?

The other answer is very complete, but here is a rule of thumb:

  • call is blocking:

    call('notepad.exe')
    print('hello')  # only executed when notepad is closed
    
  • Popen is non-blocking:

    Popen('notepad.exe')
    print('hello')  # immediately executed
    

Pass a simple string from controller to a view MVC3

Why not create a viewmodel with a simple string parameter and then pass that to the view? It has the benefit of being extensible (i.e. you can then add any other things you may want to set in your controller) and it's fairly simple.

public class MyViewModel
{
    public string YourString { get; set; }
}

In the view

@model MyViewModel
@Html.Label(model => model.YourString)

In the controller

public ActionResult Index() 
{
     myViewModel = new MyViewModel();
     myViewModel.YourString = "However you are setting this."
     return View(myViewModel)
}

link with target="_blank" does not open in new tab in Chrome

Because JavaScript is handling the click event. When you click, the following code is called:

el.addEvent('click', function(e){
    if(obj.options.onOpen){
        new Event(e).stop();
        if(obj.options.open == i){
            obj.options.open = null;
            obj.options.onClose(this.href, i);
        }else{
            obj.options.open = i;
            obj.options.onOpen(this.href, i);
        }   
    }       
})

The onOpen manually changes the location.

Edit: Regarding your comment... If you can modify ImageMenu.js, you could update the script which calls onClose to pass the a element object (this, rather than this.href)

obj.options.onClose(this, i);

Then update your ImageMenu instance, with the following onOpen change:

window.addEvent('domready', function(){
    var myMenu = new ImageMenu($$('#imageMenu a'), {
        openWidth: 310,
        border: 2,
        onOpen: function(e, i) {
            if (e.target === '_blank') {
                window.open(e.href);    
            } else {
                location = e.href;
            }
        }
    });
});

This would check for the target property of the element to see if it's _blank, and then call window.open, if found.

If you'd prefer not to modify ImageMenu.js, another option would be to modify your links to identify them in your onOpen handler. Say something like:

<a href="http://www.foracure.org.au/#_b=1" target="_blank" style="width: 105px;"></a>

Then, update your onOpen call to:

onOpen: function(e, i) {
    if (e.indexOf('_b=1') > -1) {
        window.open(e);   
    } else {
        location = e;
    }
}

The only downside to this is the user sees the hash on hover.

Finally, if the number of links that you plan to open in a new window are low, you could create a map and check against that. Something like:

var linksThatOpenInANewWindow = {
    'http://www.foracure.org.au': 1
};

onOpen: function(e, i) {
    if (linksThatOpenInANewWindow[e] === 1) {
        window.open(e);   
    } else {
        location = e
    }
}

The only downside is maintenance, depending on the number of links.

Others have suggested modifying the link (using # or javascript:) and adding an inline event handler (onclick) - I don't recommend that at all as it breaks links when JS is disabled/not supported.

Using --add-host or extra_hosts with docker-compose

It seems like it should be made possible to say:

extra_hosts:
 - "loghost:localhost"

So if the part after the colon (normally an IP address) doesn't start with a digit, then name resolution will be performed to look up an IP for localhost, and add something like to the container's /etc/hosts:

127.0.0.1 loghost

...assuming that localhost resolves to 127.0.0.1 on the host system.

It looks like it'd be really easy to add in docker-compose's source code: compose/config/types.py's parse_extra_hosts function would likely do it.

For docker itself, this would probably be addable in opts/hosts.go's ValidateExtraHost function, though then it's not strictly validating anymore, so the function would be a little misnamed.

It might actually be a little better to add this to docker, not docker-compose - docker-compose might just get it automatically if docker gets it.

Sadly, this would probably require a container bounce to change an IP address.

How to change Hash values?

new_hash = old_hash.merge(old_hash) do |_key, value, _value|
             value.upcase
           end

# old_hash = {"a" => "b", "c" => "d"}
# new_hash = {"a" => "B", "c" => "D"}

favicon not working in IE

 <link rel="shortcut icon" type="image/x-icon" href="FolderName/favicon.ico" />
  1. Your favicon.ico must be placed between head tag
  2. size : 16 X 16
  3. and for Internet Explorer it must be transparent (the outer white part should not visible)

Eclipse comment/uncomment shortcut?

Ctrl + Shift + C . Works great on .java, .xhtml, .properties and maybe on others but I only tested these ones. Can comment single or multiple lines.

Why does Maven have such a bad rep?

If you're going to bet your business or job on a development project, you want to be in control of the foundations - i.e. the build system. With Maven, you are not in control. It is declarative and opaque. The maven-framework developers have no idea how to build a transparent or intuitive system and this is clear from the log output and the documentation.

The dependency management is very tempting since it could same you some time at project inception but be warned, it is fundamentally broken and will eventually cause you a lot of headaches. When two dependencies have incompatible transient dependencies you will be blocked by a rat's nest of complexity that will break the build for your entire team and block development for days. The build process with Maven is also notoriously inconsistent for different developers in your team due to inconsistent states of their local repositories. Depending on when a developer created their environment, or what other projects they're working on, they will have different results. You'll find that you're deleting your entire local repository and having Maven re-download jars far more often than the first time setup for a dev branch. I believe OSGI is an initiative that is attempting to fix this fundamental problem. I would say that perhaps if something needs to be so complex, the fundamental premise is wrong.

I've been a maven user/victim for over 5 years now and I have to say that it will save you far more time to just check your dependencies into your source repository and write nice and simple ant tasks. With ant, you know EXACTLY what your build system is doing.

I've experienced many, many lost man weeks of time at several different companies due to Maven problems.

I've recently tried to bring an old GWT/Maven/Eclipse project back to life and 2 weeks of all my spare time later, I still can't get it to build consistently. It's time to cut my losses and develop using ant / eclipse me thinks...

Your project path contains non-ASCII characters android studio

I also encountered this problem, and I have to change the folder name from Chinese to English. Pity that current gradle build tool does not support Unicode names.

how to pass value from one php page to another using session

Solution using just POST - no $_SESSION

page1.php

<form action="page2.php" method="post">
    <textarea name="textarea1" id="textarea1"></textarea><br />
    <input type="submit" value="submit" />
</form>

page2.php

<?php
    // this page outputs the contents of the textarea if posted
    $textarea1 = ""; // set var to avoid errors
    if(isset($_POST['textarea1'])){
        $textarea1 = $_POST['textarea1']
    }
?>
<textarea><?php echo $textarea1;?></textarea>

Solution using $_SESSION and POST

page1.php

<?php

    session_start(); // needs to be before anything else on page to use $_SESSION
    $textarea1 = "";
    if(isset($_POST['textarea1'])){
        $_SESSION['textarea1'] = $_POST['textarea1'];
    }

?>


<form action="page1.php" method="post">
    <textarea name="textarea1" id="textarea1"></textarea><br />
    <input type="submit" value="submit" />
</form>
<br /><br />
<a href="page2.php">Go to page2</a>

page2.php

<?php
    session_start(); // needs to be before anything else on page to use $_SESSION
    // this page outputs the textarea1 from the session IF it exists
    $textarea1 = ""; // set var to avoid errors
    if(isset($_SESSION['textarea1'])){
        $textarea1 = $_SESSION['textarea1']
    }
?>
<textarea><?php echo $textarea1;?></textarea>

WARNING!!! - This contains no validation!!!

How to set base url for rest in spring boot?

server.servlet.context-path=/api would be the solution I guess. I had the same issue and this got me solved. I used server.context-path. However, that seemed to be deprecated and I found that server.servlet.context-path solves the issue now. Another workaround I found was adding a base tag to my front end (H5) pages. I hope this helps someone out there.

Cheers

How to upload (FTP) files to server in a bash script?

#/bin/bash
# $1 is the file name
# usage: this_script  <filename>
IP_address="xx.xxx.xx.xx"
username="username"
domain=my.ftp.domain
password=password

echo "
 verbose
 open $IP_address
 USER $username $password
 put $1
 bye
" | ftp -n > ftp_$$.log

Sublime Text 2 multiple line edit

I'm not sure it's possible "out of the box". And, unfortunately, I don't know an appropriate plugin either. To solve the problem you suggested you could use regular expressions.

  1. Cmd + F (Find)
  2. Regexp: [^ ]+ (or \d+, or whatever you prefer)
  3. Option + F (Find All)
  4. Edit it

Hotkeys may vary depending on you OS and personal preferences (mine are for OS X).

Get top most UIViewController

Where did you put the code in?

I try your code in my demo, I found out, if you put the code in

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { 

will fail, because key window have been setting yet.

But I put your code in some view controller's

override func viewDidLoad() {

It just works.

Difference between static, auto, global and local variable in the context of c and c++

Local variables are non existent in the memory after the function termination.
However static variables remain allocated in the memory throughout the life of the program irrespective of whatever function.

Additionally from your question, static variables can be declared locally in class or function scope and globally in namespace or file scope. They are allocated the memory from beginning to end, it's just the initialization which happens sooner or later.

Scrollbar without fixed height/Dynamic height with scrollbar

 <div id="scroll">
    <p>Try to add more text</p>
 </div>

here's the css code

#scroll {
   overflow-y:auto;
   height:auto;
   max-height:200px;
   border:1px solid black;
   width:300px;
 }

here's the demo JSFIDDLE

How to run a command in the background and get no output?

Use nohup if your background job takes a long time to finish or you just use SecureCRT or something like it login the server.

Redirect the stdout and stderr to /dev/null to ignore the output.

nohup /path/to/your/script.sh > /dev/null 2>&1 &

How to check if an item is selected from an HTML drop down list?

<label class="paylabel" for="cardtype">Card Type:</label>
<select id="cardtype" name="cards">
<option value="selectcard">--- Please select ---</option>
<option value="mastercard" selected="selected">Mastercard</option>
<option value="maestro">Maestro</option>
<option value="solo">Solo (UK only)</option>
<option value="visaelectron">Visa Electron</option>
<option value="visadebit">Visa Debit</option>
</select><br />

<script>
    var card = document.getElementById("cardtype");
    if (card.options[card.selectedIndex].value == 'selectcard') {
          alert("Please select a card type");
          return false;
    }
</script>

Current date without time

If you need exact your example, you should add format to ToString()

    string test = DateTime.ParseExact(DateTime.Now.ToString("dd.MM.yyyy"), "dd.MM.yyyy", CultureInfo.InvariantCulture).ToString("yyyy-MM-dd");

But it's better to use straight formatting:

    string test = DateTime.Now.ToString("yyyy-MM-dd")