Programs & Examples On #Race condition

A race condition is when multiple threads/processes/clients all use a resource, without proper use of locks.

How to get last inserted row ID from WordPress database?

Putting the call to mysql_insert_id() inside a transaction, should do it:

mysql_query('BEGIN');
// Whatever code that does the insert here.
$id = mysql_insert_id();
mysql_query('COMMIT');
// Stuff with $id.

What is a race condition?

A race condition is a situation on concurrent programming where two concurrent threads or processes compete for a resource and the resulting final state depends on who gets the resource first.

How do I find out my root MySQL password?

sudo mysql -u root
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'YOUR_PASSWORD_HERE';
FLUSH PRIVILEGES;

mysql -u root -p # and it works

Running npm command within Visual Studio Code

There is an extension available, npm Script runner. I have not tried it myself, though.

Dynamic loading of images in WPF

This is strange behavior and although I am unable to say why this is occurring, I can recommend some options.

First, an observation. If you include the image as Content in VS and copy it to the output directory, your code works. If the image is marked as None in VS and you copy it over, it doesn't work.

Solution 1: FileStream

The BitmapImage object accepts a UriSource or StreamSource as a parameter. Let's use StreamSource instead.

        FileStream stream = new FileStream("picture.png", FileMode.Open, FileAccess.Read);
        Image i = new Image();
        BitmapImage src = new BitmapImage();
        src.BeginInit();
        src.StreamSource = stream;
        src.EndInit();
        i.Source = src;
        i.Stretch = Stretch.Uniform;
        panel.Children.Add(i);

The problem: stream stays open. If you close it at the end of this method, the image will not show up. This means that the file stays write-locked on the system.

Solution 2: MemoryStream

This is basically solution 1 but you read the file into a memory stream and pass that memory stream as the argument.

        MemoryStream ms = new MemoryStream();
        FileStream stream = new FileStream("picture.png", FileMode.Open, FileAccess.Read);
        ms.SetLength(stream.Length);
        stream.Read(ms.GetBuffer(), 0, (int)stream.Length);

        ms.Flush();
        stream.Close();

        Image i = new Image();
        BitmapImage src = new BitmapImage();
        src.BeginInit();
        src.StreamSource = ms;
        src.EndInit();
        i.Source = src;
        i.Stretch = Stretch.Uniform;
        panel.Children.Add(i);

Now you are able to modify the file on the system, if that is something you require.

How do I make a JSON object with multiple arrays?

Another example:

[  
[  
    {  
        "@id":1,
        "deviceId":1,
        "typeOfDevice":"1",
        "state":"1",
        "assigned":true
    },
    {  
        "@id":2,
        "deviceId":3,
        "typeOfDevice":"3",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":3,
        "deviceId":4,
        "typeOfDevice":"júuna",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":4,
        "deviceId":5,
        "typeOfDevice":"nffjnff",
        "state":"Regular",
        "assigned":true
    },
    {  
        "@id":5,
        "deviceId":6,
        "typeOfDevice":"44",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":6,
        "deviceId":7,
        "typeOfDevice":"rr",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":7,
        "deviceId":8,
        "typeOfDevice":"j",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":8,
        "deviceId":9,
        "typeOfDevice":"55",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":9,
        "deviceId":10,
        "typeOfDevice":"5",
        "state":"Excelent",
        "assigned":true
    },
    {  
        "@id":10,
        "deviceId":11,
        "typeOfDevice":"5",
        "state":"Excelent",
        "assigned":true
    }
],
1
]

Read the array's

$.each(data[0], function(i, item) {
         data[0][i].deviceId + data[0][i].typeOfDevice  + data[0][i].state +  data[0][i].assigned 
    });

Use http://www.jsoneditoronline.org/ to understand the JSON code better

Run cURL commands from Windows console

Assuming you are new to the game or are unable to install software because of security restrictions, you could use Scoop to install curl. From a powershell or command window run the following commands. Note this assumes that you have Powershell v3.0+.

The other cool advantage here is that this installs the software for just the current user.

  1. Set execution exception

    Set-ExecutionPolicy -ExecutionPolicy Undefined -Scope CurrentUser
    
  2. Install Scoop

    iex (new-object net.webclient).downloadstring('https://get.scoop.sh')
    
  3. Install curl. You may see a warning about a missing hash, but you should see a final message that cURL was installed successfully

    scoop install curl
    
  4. Test the install of curl

    curl -L https://get.scoop.sh
    

matplotlib does not show my drawings although I call pyplot.show()

What solved my problem was just using the below two lines in ipython notebook at the top

%matplotib inline
%pylab inline

And it worked. I'm using Ubuntu16.04 and ipython-5.1

Should you commit .gitignore into the Git repos?

You typically do commit .gitignore. In fact, I personally go as far as making sure my index is always clean when I'm not working on something. (git status should show nothing.)

There are cases where you want to ignore stuff that really isn't project specific. For example, your text editor may create automatic *~ backup files, or another example would be the .DS_Store files created by OS X.

I'd say, if others are complaining about those rules cluttering up your .gitignore, leave them out and instead put them in a global excludes file.

By default this file resides in $XDG_CONFIG_HOME/git/ignore (defaults to ~/.config/git/ignore), but this location can be changed by setting the core.excludesfile option. For example:

git config --global core.excludesfile ~/.gitignore

Simply create and edit the global excludesfile to your heart's content; it'll apply to every git repository you work on on that machine.

how to read certain columns from Excel using Pandas - Python

parse_cols is deprecated, use usecols instead

that is:

df = pd.read_excel(file_loc, index_col=None, na_values=['NA'], usecols = "A,C:AA")

React js onClick can't pass value to method

There were a lot of performance considerations, all in the vacuum.
The issue with this handlers is that you need to curry them in order to incorporate the argument that you can't name in the props.
This means that the component needs a handler for each and every clickable element. Let's agree that for a few buttons this is not an issue, right?
The problem arises when you are handling tabular data with dozens of columns and thousands of rows. There you notice the impact of creating that many handlers.

The fact is, I only need one.
I set the handler at the table level (or UL or OL...), and when the click happens I can tell which was the clicked cell using data available since ever in the event object:

nativeEvent.target.tagName
nativeEvent.target.parentElement.tagName 
nativeEvent.target.parentElement.rowIndex
nativeEvent.target.cellIndex
nativeEvent.target.textContent

I use the tagname fields to check that the click happened in a valid element, for example ignore clicks in THs ot footers.
The rowIndex and cellIndex give the exact location of the clicked cell.
Textcontent is the text of the clicked cell.

This way I don't need to pass the cell's data to the handler, it can self-service it.
If I needed more data, data that is not to be displayed, I can use the dataset attribute, or hidden elements.
With some simple DOM navigation it's all at hand.
This has been used in HTML since ever, since PCs were much easier to bog.

Pass a PHP array to a JavaScript function

In the following example you have an PHP array, then firstly create a JavaScript array by a PHP array:

<script type="javascript">
    day = new Array(<?php echo implode(',', $day); ?>);
    week = new Array(<?php echo implode(',',$week); ?>);
    month = new Array(<?php echo implode(',',$month); ?>);

    <!--  Then pass it to the JavaScript function:   -->

    drawChart(<?php echo count($day); ?>, day, week, month);
</script>

generate model using user:references vs user_id:integer

how does rails know that user_id is a foreign key referencing user?

Rails itself does not know that user_id is a foreign key referencing user. In the first command rails generate model Micropost user_id:integer it only adds a column user_id however rails does not know the use of the col. You need to manually put the line in the Micropost model

class Micropost < ActiveRecord::Base
  belongs_to :user
end

class User < ActiveRecord::Base
  has_many :microposts
end

the keywords belongs_to and has_many determine the relationship between these models and declare user_id as a foreign key to User model.

The later command rails generate model Micropost user:references adds the line belongs_to :user in the Micropost model and hereby declares as a foreign key.

FYI
Declaring the foreign keys using the former method only lets the Rails know about the relationship the models/tables have. The database is unknown about the relationship. Therefore when you generate the EER Diagrams using software like MySql Workbench you find that there is no relationship threads drawn between the models. Like in the following pic enter image description here

However, if you use the later method you find that you migration file looks like:

def change
    create_table :microposts do |t|
      t.references :user, index: true

      t.timestamps null: false
    end
    add_foreign_key :microposts, :users

Now the foreign key is set at the database level. and you can generate proper EER diagrams. enter image description here

Populate one dropdown based on selection in another

Setup mine within a closure and with straight JavaScript, explanation provided in comments

_x000D_
_x000D_
(function() {_x000D_
_x000D_
  //setup an object fully of arrays_x000D_
  //alternativly it could be something like_x000D_
  //{"yes":[{value:sweet, text:Sweet}.....]}_x000D_
  //so you could set the label of the option tag something different than the name_x000D_
  var bOptions = {_x000D_
    "yes": ["sweet", "wohoo", "yay"],_x000D_
    "no": ["you suck!", "common son"]_x000D_
  };_x000D_
_x000D_
  var A = document.getElementById('A');_x000D_
  var B = document.getElementById('B');_x000D_
_x000D_
  //on change is a good event for this because you are guarenteed the value is different_x000D_
  A.onchange = function() {_x000D_
    //clear out B_x000D_
    B.length = 0;_x000D_
    //get the selected value from A_x000D_
    var _val = this.options[this.selectedIndex].value;_x000D_
    //loop through bOption at the selected value_x000D_
    for (var i in bOptions[_val]) {_x000D_
      //create option tag_x000D_
      var op = document.createElement('option');_x000D_
      //set its value_x000D_
      op.value = bOptions[_val][i];_x000D_
      //set the display label_x000D_
      op.text = bOptions[_val][i];_x000D_
      //append it to B_x000D_
      B.appendChild(op);_x000D_
    }_x000D_
  };_x000D_
  //fire this to update B on load_x000D_
  A.onchange();_x000D_
_x000D_
})();
_x000D_
<select id='A' name='A'>_x000D_
  <option value='yes' selected='selected'>yes_x000D_
  <option value='no'> no_x000D_
</select>_x000D_
<select id='B' name='B'>_x000D_
</select>
_x000D_
_x000D_
_x000D_

How to apply style classes to td classes?

table.classname td {
    font-size: 90%;
}

worked for me. thanks.

Set database from SINGLE USER mode to MULTI USER

You can add the option to rollback your change immediately.

ALTER DATABASE BARDABARD
SET MULTI_USER
WITH ROLLBACK IMMEDIATE
GO

How do I make the return type of a method generic?

You need to make it a generic method, like this:

public static T ConfigSetting<T>(string settingName)
{  
    return /* code to convert the setting to T... */
}

But the caller will have to specify the type they expect. You could then potentially use Convert.ChangeType, assuming that all the relevant types are supported:

public static T ConfigSetting<T>(string settingName)
{  
    object value = ConfigurationManager.AppSettings[settingName];
    return (T) Convert.ChangeType(value, typeof(T));
}

I'm not entirely convinced that all this is a good idea, mind you...

Javascript | Set all values of an array

map is the most logical solution for this problem.

let xs = [1, 2, 3];
xs = xs.map(x => 42);
xs // -> [42, 42, 42]

However, if there is a chance that the array is sparse, you'll need to use for or, even better, for .. of.

See:

Show DialogFragment with animation growing from a point

DialogFragment has a public getTheme() method that you can over ride for this exact reason. This solution uses less lines of code:

public class MyCustomDialogFragment extends DialogFragment{
    ...
    @Override
    public int getTheme() {
        return R.style.MyThemeWithCustomAnimation;
    }
}

File path issues in R using Windows ("Hex digits in character string" error)

I know this is really old, but if you are copying and pasting anyway, you can just use:

read.csv(readClipboard())

readClipboard() escapes the back-slashes for you. Just remember to make sure the ".csv" is included in your copy, perhaps with this:

read.csv(paste0(readClipboard(),'.csv'))

And if you really want to minimize your typing you can use some functions:

setWD <- function(){
  setwd(readClipboard())
}


readCSV <- function(){
  return(readr::read_csv(paste0(readClipboard(),'.csv')))
} 

#copy directory path
setWD()

#copy file name
df <- readCSV()

How to fix a collation conflict in a SQL Server query?

Adding to the accepted answer, you can used DATABASE_DEFAULT as encoding.

This allows database to make choice for you and your code becomes more portable.

SELECT MyColumn
FROM 
    FirstTable a
        INNER JOIN SecondTable b
            ON a.MyID COLLATE DATABASE_DEFAULT = b.YourID COLLATE DATABASE_DEFAULT

Time complexity of nested for-loop

Indeed, it is O(n^2). See also a very similar example with the same runtime here.

How to change current Theme at runtime in Android

This had no effect for me:

public void changeTheme(int newTheme) {
    setTheme(newTheme);
    recreate();
}

But this worked:

int theme = R.style.default;

protected void onCreate(Bundle savedInstanceState) {
    setTheme(this.theme);
    super.onCreate(savedInstanceState);
}

public void changeTheme(int newTheme) {
    this.theme = newTheme;
    recreate();
}

Difference between require, include, require_once and include_once?

From the manual:

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

The same is true for the _once() variants.

How can I create a link to a local file on a locally-run web page?

I've a way and work like this:

<'a href="FOLDER_PATH" target="_explorer.exe">Link Text<'/a>

Force index use in Oracle

There is an appropriate index on column_having_index, and its use actually increase performance, but Oracle didn't use it...
You should gather statistics on your table to let optimizer see that index access can help. Using direct hint is not a good practice.

Standard concise way to copy a file in Java?

public static void copyFile(File src, File dst) throws IOException
{
    long p = 0, dp, size;
    FileChannel in = null, out = null;

    try
    {
        if (!dst.exists()) dst.createNewFile();

        in = new FileInputStream(src).getChannel();
        out = new FileOutputStream(dst).getChannel();
        size = in.size();

        while ((dp = out.transferFrom(in, p, size)) > 0)
        {
            p += dp;
        }
    }
    finally {
        try
        {
            if (out != null) out.close();
        }
        finally {
            if (in != null) in.close();
        }
    }
}

CSS:Defining Styles for input elements inside a div

When you say "called" I'm going to assume you mean an ID tag.

To make it cross-brower, I wouldn't suggest using the CSS3 [], although it is an option. This being said, give each of your textboxes a class like "tb" and the radio button "rb".

Then:

#divContainer .tb { width: 150px }
#divContainer .rb { width: 20px }

This assumes you are using the same classes elsewhere, if not, this will suffice:

.tb { width: 150px }
.rb { width: 20px }

As @David mentioned, to access anything within the division itself:

#divContainer [element] { ... }

Where [element] is whatever HTML element you need.

Remove non-utf8 characters from string

$text = iconv("UTF-8", "UTF-8//IGNORE", $text);

This is what I am using. Seems to work pretty well. Taken from http://planetozh.com/blog/2005/01/remove-invalid-characters-in-utf-8/

How do I profile memory usage in Python?

A simple example to calculate the memory usage of a block of codes / function using memory_profile, while returning result of the function:

import memory_profiler as mp

def fun(n):
    tmp = []
    for i in range(n):
        tmp.extend(list(range(i*i)))
    return "XXXXX"

calculate memory usage before running the code then calculate max usage during the code:

start_mem = mp.memory_usage(max_usage=True)
res = mp.memory_usage(proc=(fun, [100]), max_usage=True, retval=True) 
print('start mem', start_mem)
print('max mem', res[0][0])
print('used mem', res[0][0]-start_mem)
print('fun output', res[1])

calculate usage in sampling points while running function:

res = mp.memory_usage((fun, [100]), interval=.001, retval=True)
print('min mem', min(res[0]))
print('max mem', max(res[0]))
print('used mem', max(res[0])-min(res[0]))
print('fun output', res[1])

Credits: @skeept

What are the differences between git remote prune, git prune, git fetch --prune, etc

git remote prune and git fetch --prune do the same thing: deleting the refs to the branches that don't exist on the remote, as you said. The second command connects to the remote and fetches its current branches before pruning.

However it doesn't touch the local branches you have checked out, that you can simply delete with

git branch -d  random_branch_I_want_deleted

Replace -d by -D if the branch is not merged elsewhere

git prune does something different, it purges unreachable objects, those commits that aren't reachable in any branch or tag, and thus not needed anymore.

Declaring static constants in ES6 classes?

It is also possible to use Object.freeze on you class(es6)/constructor function(es5) object to make it immutable:

class MyConstants {}
MyConstants.staticValue = 3;
MyConstants.staticMethod = function() {
  return 4;
}
Object.freeze(MyConstants);
// after the freeze, any attempts of altering the MyConstants class will have no result
// (either trying to alter, add or delete a property)
MyConstants.staticValue === 3; // true
MyConstants.staticValue = 55; // will have no effect
MyConstants.staticValue === 3; // true

MyConstants.otherStaticValue = "other" // will have no effect
MyConstants.otherStaticValue === undefined // true

delete MyConstants.staticMethod // false
typeof(MyConstants.staticMethod) === "function" // true

Trying to alter the class will give you a soft-fail (won't throw any errors, it will simply have no effect).

ssh-copy-id no identities found error

Generating ssh keys on the client solved it for me

$ ssh-keygen -t rsa

When should I use cross apply over inner join?

This has already been answered very well technically, but let me give a concrete example of how it's extremely useful:

Lets say you have two tables, Customer and Order. Customers have many Orders.

I want to create a view that gives me details about customers, and the most recent order they've made. With just JOINS, this would require some self-joins and aggregation which isn't pretty. But with Cross Apply, its super easy:

SELECT *
FROM Customer
CROSS APPLY (
  SELECT TOP 1 *
  FROM Order
  WHERE Order.CustomerId = Customer.CustomerId
  ORDER BY OrderDate DESC
) T

How do I convert a calendar week into a date in Excel?

For ISO week numbers you can use this formula to get the Monday

=DATE(A2,1,-2)-WEEKDAY(DATE(A2,1,3))+B2*7

assuming year in A2 and week number in B2

it's the same as my answer here https://stackoverflow.com/a/10855872/1124287

How do I get the current time only in JavaScript

This how you can do it.

_x000D_
_x000D_
const date = new Date();_x000D_
const time = date.toTimeString().split(' ')[0].split(':');_x000D_
console.log(time[0] + ':' + time[1])
_x000D_
_x000D_
_x000D_

Difference Between Select and SelectMany

Here is a code example with an initialized small collection for testing:

class Program
{
    static void Main(string[] args)
    {
        List<Order> orders = new List<Order>
        {
            new Order
            {
                OrderID = "orderID1",
                OrderLines = new List<OrderLine>
                {
                    new OrderLine
                    {
                        ProductSKU = "SKU1",
                        Quantity = 1
                    },
                    new OrderLine
                    {
                        ProductSKU = "SKU2",
                        Quantity = 2
                    },
                    new OrderLine
                    {
                        ProductSKU = "SKU3",
                        Quantity = 3
                    }
                }
            },
            new Order
            {
                OrderID = "orderID2",
                OrderLines = new List<OrderLine>
                {
                    new OrderLine
                    {
                        ProductSKU = "SKU4",
                        Quantity = 4
                    },
                    new OrderLine
                    {
                        ProductSKU = "SKU5",
                        Quantity = 5
                    }
                }
            }
        };

        //required result is the list of all SKUs in orders
        List<string> allSKUs = new List<string>();

        //With Select case 2 foreach loops are required
        var flattenedOrdersLinesSelectCase = orders.Select(o => o.OrderLines);
        foreach (var flattenedOrderLine in flattenedOrdersLinesSelectCase)
        {
            foreach (OrderLine orderLine in flattenedOrderLine)
            {
                allSKUs.Add(orderLine.ProductSKU);
            }
        }

        //With SelectMany case only one foreach loop is required
        allSKUs = new List<string>();
        var flattenedOrdersLinesSelectManyCase = orders.SelectMany(o => o.OrderLines);
        foreach (var flattenedOrderLine in flattenedOrdersLinesSelectManyCase)
        {
            allSKUs.Add(flattenedOrderLine.ProductSKU);
        }

       //If the required result is flattened list which has OrderID, ProductSKU and Quantity,
       //SelectMany with selector is very helpful to get the required result
       //and allows avoiding own For loops what according to my experience do code faster when
       // hundreds of thousands of data rows must be operated
        List<OrderLineForReport> ordersLinesForReport = (List<OrderLineForReport>)orders.SelectMany(o => o.OrderLines,
            (o, ol) => new OrderLineForReport
            {
                OrderID = o.OrderID,
                ProductSKU = ol.ProductSKU,
                Quantity = ol.Quantity
            }).ToList();
    }
}
class Order
{
    public string OrderID { get; set; }
    public List<OrderLine> OrderLines { get; set; }
}
class OrderLine
{
    public string ProductSKU { get; set; }
    public int Quantity { get; set; }
}
class OrderLineForReport
{
    public string OrderID { get; set; }
    public string ProductSKU { get; set; }
    public int Quantity { get; set; }
}

Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing

This might sound stupid, but, in the first problem presented to you, you would have to see all the remaining numbers in the bag to actually add them up to find the missing number using that equation.

So, since you get to see all the numbers, just look for the number that's missing. The same goes for when two numbers are missing. Pretty simple I think. No point in using an equation when you get to see the numbers remaining in the bag.

Understanding .get() method in Python

I see this is a fairly old question, but this looks like one of those times when something's been written without knowledge of a language feature. The collections library exists to fulfill these purposes.

from collections import Counter
letter_counter = Counter()
for letter in 'The quick brown fox jumps over the lazy dog':
    letter_counter[letter] += 1

>>> letter_counter
Counter({' ': 8, 'o': 4, 'e': 3, 'h': 2, 'r': 2, 'u': 2, 'T': 1, 'a': 1, 'c': 1, 'b': 1, 'd': 1, 'g': 1, 'f': 1, 'i': 1, 'k': 1, 'j': 1, 'm': 1, 'l': 1, 'n': 1, 'q': 1, 'p': 1, 's': 1, 't': 1, 'w': 1, 'v': 1, 'y': 1, 'x': 1, 'z': 1})

In this example the spaces are being counted, obviously, but whether or not you want those filtered is up to you.

As for the dict.get(a_key, default_value), there have been several answers to this particular question -- this method returns the value of the key, or the default_value you supply. The first argument is the key you're looking for, the second argument is the default for when that key is not present.

Disable/enable an input with jQuery?

Disable:

$('input').attr('readonly', true); // Disable it.
$('input').addClass('text-muted'); // Gray it out with bootstrap.

Enable:

$('input').attr('readonly', false); // Enable it.
$('input').removeClass('text-muted'); // Back to normal color with bootstrap.

How do you right-justify text in an HTML textbox?

Using inline styles:

<input type="text" style="text-align: right"/>

or, put it in a style sheet, like so:

<style>
   .rightJustified {
        text-align: right;
    }
</style>

and reference the class:

<input type="text" class="rightJustified"/>

MySQL foreign key constraints, cascade delete

I think (I'm not certain) that foreign key constraints won't do precisely what you want given your table design. Perhaps the best thing to do is to define a stored procedure that will delete a category the way you want, and then call that procedure whenever you want to delete a category.

CREATE PROCEDURE `DeleteCategory` (IN category_ID INT)
LANGUAGE SQL
NOT DETERMINISTIC
MODIFIES SQL DATA
SQL SECURITY DEFINER
BEGIN

DELETE FROM
    `products`
WHERE
    `id` IN (
        SELECT `products_id`
        FROM `categories_products`
        WHERE `categories_id` = category_ID
    )
;

DELETE FROM `categories`
WHERE `id` = category_ID;

END

You also need to add the following foreign key constraints to the linking table:

ALTER TABLE `categories_products` ADD
    CONSTRAINT `Constr_categoriesproducts_categories_fk`
    FOREIGN KEY `categories_fk` (`categories_id`) REFERENCES `categories` (`id`)
    ON DELETE CASCADE ON UPDATE CASCADE,
    CONSTRAINT `Constr_categoriesproducts_products_fk`
    FOREIGN KEY `products_fk` (`products_id`) REFERENCES `products` (`id`)
    ON DELETE CASCADE ON UPDATE CASCADE

The CONSTRAINT clause can, of course, also appear in the CREATE TABLE statement.

Having created these schema objects, you can delete a category and get the behaviour you want by issuing CALL DeleteCategory(category_ID) (where category_ID is the category to be deleted), and it will behave how you want. But don't issue a normal DELETE FROM query, unless you want more standard behaviour (i.e. delete from the linking table only, and leave the products table alone).

How to map to multiple elements with Java 8 streams?

To do this, I had to come up with an intermediate data structure:

class KeyDataPoint {
    String key;
    DateTime timestamp;
    Number data;
    // obvious constructor and getters
}

With this in place, the approach is to "flatten" each MultiDataPoint into a list of (timestamp, key, data) triples and stream together all such triples from the list of MultiDataPoint.

Then, we apply a groupingBy operation on the string key in order to gather the data for each key together. Note that a simple groupingBy would result in a map from each string key to a list of the corresponding KeyDataPoint triples. We don't want the triples; we want DataPoint instances, which are (timestamp, data) pairs. To do this we apply a "downstream" collector of the groupingBy which is a mapping operation that constructs a new DataPoint by getting the right values from the KeyDataPoint triple. The downstream collector of the mapping operation is simply toList which collects the DataPoint objects of the same group into a list.

Now we have a Map<String, List<DataPoint>> and we want to convert it to a collection of DataSet objects. We simply stream out the map entries and construct DataSet objects, collect them into a list, and return it.

The code ends up looking like this:

Collection<DataSet> convertMultiDataPointToDataSet(List<MultiDataPoint> multiDataPoints) {
    return multiDataPoints.stream()
        .flatMap(mdp -> mdp.getData().entrySet().stream()
                           .map(e -> new KeyDataPoint(e.getKey(), mdp.getTimestamp(), e.getValue())))
        .collect(groupingBy(KeyDataPoint::getKey,
                    mapping(kdp -> new DataPoint(kdp.getTimestamp(), kdp.getData()), toList())))
        .entrySet().stream()
        .map(e -> new DataSet(e.getKey(), e.getValue()))
        .collect(toList());
}

I took some liberties with constructors and getters, but I think they should be obvious.

Save array in mysql database

<?php
$myArray = new array('1', '2');
$seralizedArray = serialize($myArray);
?>

How to iterate over a JSONObject?

org.json.JSONObject now has a keySet() method which returns a Set<String> and can easily be looped through with a for-each.

for(String key : jsonObject.keySet())

Save results to csv file with Python

Use csv.writer:

import csv

with open('thefile.csv', 'rb') as f:
  data = list(csv.reader(f))

import collections
counter = collections.defaultdict(int)
for row in data:
    counter[row[0]] += 1


writer = csv.writer(open("/path/to/my/csv/file", 'w'))
for row in data:
    if counter[row[0]] >= 4:
        writer.writerow(row)

Using sed, Insert a line above or below the pattern?

To append after the pattern: (-i is for in place replace). line1 and line2 are the lines you want to append(or prepend)

sed -i '/pattern/a \
line1 \
line2' inputfile

Output:

#cat inputfile
 pattern
 line1 line2 

To prepend the lines before:

sed -i '/pattern/i \
line1 \
line2' inputfile

Output:

#cat inputfile
 line1 line2 
 pattern

Open Cygwin at a specific folder

I have created the batch file and put it to the Cygwin's /bin directory. This script was developed so it allows to install/uninstall the registry entries for opening selected folders and drives in Cygwin. For details see the link http://with-love-from-siberia.blogspot.com/2013/12/cygwin-here.html.

update: This solution does the same as early suggestions but all manipulations with Windows Registry are hidden within the script.

Perform the command to install

cyghere.bat /install

Perform the command to uninstall

cyghere.bat /uninstall

ERROR 1064 (42000) in MySQL

Finally got a solution.

First .sql file converts into the UTF8.

Then use this command

mysql -p -u root --default_character_set utf8 test </var/201535.sql

---root is the username

---test is the database name

or

mysql -p -u root test < /var/201535.sql 

---root is the username

---test is the database name

How to check db2 version

SELECT GETVARIABLE(('SYSIBM.VERSION')
 FROM SYSIBM.SYSDUMMY1;
-- PPP IS PRODUCT STRING 'DSN'
-- VV IS VERSION NUMBER E.G., 10, 11
-- M IS MAINTENANCE LEVEL E.G. 5

-DISPLAY GROUP
 THIS WILL DISPLAY THE LEVEL CM, ENFM, N

What are .dex files in Android?

.dex file

Compiled Android application code file.

Android programs are compiled into .dex (Dalvik Executable) files, which are in turn zipped into a single .apk file on the device. .dex files can be created automatically by Android, by translating the compiled applications written in the Java programming language.

Copy output of a JavaScript variable to the clipboard

For general purposes of copying any text to the clipboard, I wrote the following function:

function textToClipboard (text) {
    var dummy = document.createElement("textarea");
    document.body.appendChild(dummy);
    dummy.value = text;
    dummy.select();
    document.execCommand("copy");
    document.body.removeChild(dummy);
}

The value of the parameter is inserted into value of a newly created <textarea>, which is then selected, its value is copied to the clipboard and then it gets removed from the document.

How to pass variable number of arguments to a PHP function

If you have your arguments in an array, you might be interested by the call_user_func_array function.

If the number of arguments you want to pass depends on the length of an array, it probably means you can pack them into an array themselves -- and use that one for the second parameter of call_user_func_array.

Elements of that array you pass will then be received by your function as distinct parameters.


For instance, if you have this function :

function test() {
  var_dump(func_num_args());
  var_dump(func_get_args());
}

You can pack your parameters into an array, like this :

$params = array(
  10,
  'glop',
  'test',
);

And, then, call the function :

call_user_func_array('test', $params);

This code will the output :

int 3

array
  0 => int 10
  1 => string 'glop' (length=4)
  2 => string 'test' (length=4)

ie, 3 parameters ; exactly like iof the function was called this way :

test(10, 'glop', 'test');

How to test abstract class in Java with JUnit?

I would create a jUnit inner class that inherits from the abstract class. This can be instantiated and have access to all the methods defined in the abstract class.

public class AbstractClassTest {
   public void testMethod() {
   ...
   }
}


class ConcreteClass extends AbstractClass {

}

How to force open links in Chrome not download them?

I think the question was about to open a local file directly instead of downloading a local file to the download folder and open the file in the download folder, which seems not possible in Chrome, except some add-on mentioned above.

My workaround would be to right click -> Copy the link location Windows + R and paste the link there and Enter It will go to the file directly.

Why is Python running my module when I import it, and how do I stop it?

There was a Python enhancement proposal PEP 299 which aimed to replace if __name__ == '__main__': idiom with def __main__:, but it was rejected. It's still a good read to know what to keep in mind when using if __name__ = '__main__':.

How to Set a Custom Font in the ActionBar Title?

If you want to set typeface to all the TextViews in the entire Activity you can use something like this:

public static void setTypefaceToAll(Activity activity)
{
    View view = activity.findViewById(android.R.id.content).getRootView();
    setTypefaceToAll(view);
}

public static void setTypefaceToAll(View view)
{
    if (view instanceof ViewGroup)
    {
        ViewGroup g = (ViewGroup) view;
        int count = g.getChildCount();
        for (int i = 0; i < count; i++)
            setTypefaceToAll(g.getChildAt(i));
    }
    else if (view instanceof TextView)
    {
        TextView tv = (TextView) view;
        setTypeface(tv);
    }
}

public static void setTypeface(TextView tv)
{
    TypefaceCache.setFont(tv, TypefaceCache.FONT_KOODAK);
}

And the TypefaceCache:

import java.util.TreeMap;

import android.graphics.Typeface;
import android.widget.TextView;

public class TypefaceCache {

    //Font names from asset:
    public static final String FONT_ROBOTO_REGULAR = "fonts/Roboto-Regular.ttf";
    public static final String FONT_KOODAK = "fonts/Koodak.ttf";

    private static TreeMap<String, Typeface> fontCache = new TreeMap<String, Typeface>();

    public static Typeface getFont(String fontName) {
        Typeface tf = fontCache.get(fontName);
        if(tf == null) {
            try {
                tf = Typeface.createFromAsset(MyApplication.getAppContext().getAssets(), fontName);
            }
            catch (Exception e) {
                return null;
            }
            fontCache.put(fontName, tf);
        }
        return tf;
    }

    public static void setFont(TextView tv, String fontName)
    {
        tv.setTypeface(getFont(fontName));
    }
}

How to change the port number for Asp.Net core app?

We can use this command to run our host project via Windows Powershell without IIS and visual studio on a separate port. Default of krestel web server is 5001

$env:ASPNETCORE_URLS="http://localhost:22742" ; dotnet run

Where can I find a list of escape characters required for my JSON ajax return type?

The JSON reference states:

 any-Unicode-character-
     except-"-or-\\-or-
     control-character

Then lists the standard escape codes:

  \" Standard JSON quote
  \\ Backslash (Escape char)
  \/ Forward slash
  \b Backspace (ascii code 08)
  \f Form feed (ascii code 0C)
  \n Newline
  \r Carriage return
  \t Horizontal Tab
  \u four-hex-digits

From this I assumed that I needed to escape all the listed ones and all the other ones are optional. You can choose to encode all characters into \uXXXX if you so wished, or you could only do any non-printable 7-bit ASCII characters or characters with Unicode value not in \u0020 <= x <= \u007E range (32 - 126). Preferably do the standard characters first for shorter escape codes and thus better readability and performance.

Additionally you can read point 2.5 (Strings) from RFC 4627.

You may (or may not) want to (further) escape other characters depending on where you embed that JSON string, but that is outside the scope of this question.

Swift: print() vs println() vs NSLog()

To add to Rob's answer, since iOS 10.0, Apple has introduced an entirely new "Unified Logging" system that supersedes existing logging systems (including ASL and Syslog, NSLog), and also surpasses existing logging approaches in performance, thanks to its new techniques including log data compression and deferred data collection.

From Apple:

The unified logging system provides a single, efficient, performant API for capturing messaging across all levels of the system. This unified system centralizes the storage of log data in memory and in a data store on disk.

Apple highly recommends using os_log going forward to log all kinds of messages, including info, debug, error messages because of its much improved performance compared to previous logging systems, and its centralized data collection allowing convenient log and activity inspection for developers. In fact, the new system is likely so low-footprint that it won't cause the "observer effect" where your bug disappears if you insert a logging command, interfering the timing of the bug to happen.

Performance of Activity Tracing, now part of the new Unified Logging system

You can learn more about this in details here.

To sum it up: use print() for your personal debugging for convenience (but the message won't be logged when deployed on user devices). Then, use Unified Logging (os_log) as much as possible for everything else.

How do I check to see if my array includes an object?

Why not do it simply by picking eight different numbers from 0 to Horse.count and use that to get your horses?

offsets = (0...Horse.count).to_a.sample(8)
@suggested_horses = offsets.map{|i| Horse.first(:offset => i) }

This has the added advantage that it won't cause an infinite loop if you happen to have less than 8 horses in your database.

Note: Array#sample is new to 1.9 (and coming in 1.8.8), so either upgrade your Ruby, require 'backports' or use something like shuffle.first(n).

Connect to mysql on Amazon EC2 from a remote server

The default ip of Mysql in instance EC2 Ubuntu is 127.0.0.1 if you want to change it is just to follow the answers that have already been given here.

Calculating sum of repeated elements in AngularJS ng-repeat

You can use a custom Angular filter that takes the dataset object array and the key in each object to sum. The filter can then return the sum:

.filter('sumColumn', function(){
        return function(dataSet, columnToSum){
            let sum = 0;

            for(let i = 0; i < dataSet.length; i++){
                sum += parseFloat(dataSet[i][columnToSum]) || 0;
            }

            return sum;
        };
    })

Then in your table to sum a column you can use:

<th>{{ dataSet | sumColumn: 'keyInObjectToSum' }}</th>

SQLAlchemy: how to filter date field?

In fact, your query is right except for the typo: your filter is excluding all records: you should change the <= for >= and vice versa:

qry = DBSession.query(User).filter(
        and_(User.birthday <= '1988-01-17', User.birthday >= '1985-01-17'))
# or same:
qry = DBSession.query(User).filter(User.birthday <= '1988-01-17').\
        filter(User.birthday >= '1985-01-17')

Also you can use between:

qry = DBSession.query(User).filter(User.birthday.between('1985-01-17', '1988-01-17'))

How do I stretch an image to fit the whole background (100% height x 100% width) in Flutter?

The following will fit the image to 100% of container width while the height is constant. For local assets, use AssetImage

Container(
  width: MediaQuery.of(context).size.width,
  height: 100,
  decoration: BoxDecoration(
    image: DecorationImage(
      fit: BoxFit.fill,
      image: NetworkImage("https://picsum.photos/250?image=9"),
    ),
  ),
)

Image fill modes:

  • Fill - Image is stretched

    fit: BoxFit.fill
    

    enter image description here


  • Fit Height - image kept proportional while making sure the full height of the image is shown (may overflow)

    fit: BoxFit.fitHeight
    

    enter image description here


  • Fit Width - image kept proportional while making sure the full width of the image is shown (may overflow)

    fit: BoxFit.fitWidth
    

    enter image description here


  • Cover - image kept proportional, ensures maximum coverage of the container (may overflow)

    fit: BoxFit.cover
    

    enter image description here


  • Contain - image kept proportional, minimal as possible, will reduce it's size if needed to display the entire image

    fit: BoxFit.contain
    

    enter image description here

c# .net change label text

Old question, but I had this issue as well, so after assigning the Text property, calling Refresh() will update the text.

Label1.Text = "Du har nu lånat filmen:" + test;
Refresh();

How to use tick / checkmark symbol (?) instead of bullets in unordered list?

Here are three different checkmark styles you can use:

_x000D_
_x000D_
ul:first-child  li:before { content:"\2713\0020"; }  /* OR */_x000D_
ul:nth-child(2) li:before { content:"\2714\0020"; }  /* OR */_x000D_
ul:last-child   li:before { content:"\2611\0020"; }_x000D_
ul { list-style-type: none; }
_x000D_
<ul>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
</ul>_x000D_
_x000D_
<ul>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
</ul>_x000D_
_x000D_
<ul><!-- not working on Stack snippet; check fiddle demo -->_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
  <li>this is my text</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

jsFiddle

References:

ImportError: Cannot import name X

Don't name your current python script with the name of some other module you import

Solution: rename your working python script

Example:

  1. you are working in medicaltorch.py
  2. in that script, you have: from medicaltorch import datasets as mt_datasets where medicaltorch is supposed to be an installed module

This will fail with the ImportError. Just rename your working python script in 1.

C++ deprecated conversion from string constant to 'char*'

I solve this problem by adding this macro in the beginning of the code, somewhere. Or add it in <iostream>, hehe.

 #define C_TEXT( text ) ((char*)std::string( text ).c_str())

How can I get the current user directory?

you can use the following code:

if(Platform.Equals("WinCE"))
{
    m_CurrentPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase);
}
else if(Platform.Equals("Win32NT"))
{
    m_CurrentPath = Directory.GetCurrentDirectory();
}

more information see: Get Current Directory Path in both WinXP and WinCE with C#

How to determine if a type implements an interface with C# reflection

Use Type.IsAssignableFrom:

typeof(IMyInterface).IsAssignableFrom(typeof(MyType));

How to split a string to 2 strings in C

This is how you implement a strtok() like function (taken from a BSD licensed string processing library for C, called zString).

Below function differs from the standard strtok() in the way it recognizes consecutive delimiters, whereas the standard strtok() does not.

char *zstring_strtok(char *str, const char *delim) {
    static char *static_str=0;      /* var to store last address */
    int index=0, strlength=0;       /* integers for indexes */
    int found = 0;                  /* check if delim is found */

    /* delimiter cannot be NULL
    * if no more char left, return NULL as well
    */
    if (delim==0 || (str == 0 && static_str == 0))
        return 0;

    if (str == 0)
        str = static_str;

    /* get length of string */
    while(str[strlength])
        strlength++;

    /* find the first occurance of delim */
    for (index=0;index<strlength;index++)
        if (str[index]==delim[0]) {
            found=1;
            break;
        }

    /* if delim is not contained in str, return str */
    if (!found) {
        static_str = 0;
        return str;
    }

    /* check for consecutive delimiters
    *if first char is delim, return delim
    */
    if (str[0]==delim[0]) {
        static_str = (str + 1);
        return (char *)delim;
    }

    /* terminate the string
    * this assignmetn requires char[], so str has to
    * be char[] rather than *char
    */
    str[index] = '\0';

    /* save the rest of the string */
    if ((str + index + 1)!=0)
        static_str = (str + index + 1);
    else
        static_str = 0;

        return str;
}

Below is an example code that demonstrates the usage

  Example Usage
      char str[] = "A,B,,,C";
      printf("1 %s\n",zstring_strtok(s,","));
      printf("2 %s\n",zstring_strtok(NULL,","));
      printf("3 %s\n",zstring_strtok(NULL,","));
      printf("4 %s\n",zstring_strtok(NULL,","));
      printf("5 %s\n",zstring_strtok(NULL,","));
      printf("6 %s\n",zstring_strtok(NULL,","));

  Example Output
      1 A
      2 B
      3 ,
      4 ,
      5 C
      6 (null)

You can even use a while loop (standard library's strtok() would give the same result here)

char s[]="some text here;
do {
    printf("%s\n",zstring_strtok(s," "));
} while(zstring_strtok(NULL," "));

What's the best way to validate an XML file against an XSD file?

If you have a Linux-Machine you could use the free command-line tool SAXCount. I found this very usefull.

SAXCount -f -s -n my.xml

It validates against dtd and xsd. 5s for a 50MB file.

In debian squeeze it is located in the package "libxerces-c-samples".

The definition of the dtd and xsd has to be in the xml! You can't config them separately.

Array Index Out of Bounds Exception (Java)

This is Very Good Example of minus Length of an array in java, i am giving here both examples

 public static int linearSearchArray(){

   int[] arrayOFInt = {1,7,5,55,89,1,214,78,2,0,8,2,3,4,7};
   int key = 7;
   int i = 0;
   int count = 0;
   for ( i = 0; i< arrayOFInt.length; i++){
        if ( arrayOFInt[i]  == key ){
         System.out.println("Key Found in arrayOFInt = " + arrayOFInt[i] );
         count ++;
        }
   }

   System.out.println("this Element found the ("+ count +") number of Times");
return i;  
}

this above i < arrayOFInt.length; not need to minus one by length of array; but if you i <= arrayOFInt.length -1; is necessary other wise arrayOutOfIndexException Occur, hope this will help you.

Java Compare Two List's object values?

I know it's old question but in case anyone needs it. I use this in my application and it works well. i used it to check if the cart has been changed or not.

private boolean validateOrderProducts(Cart cart) {
    boolean doesProductsChanged = false;
    if (originalProductsList.size() == cart.getCartItemsList().size()) {
        for (Product originalProduct : originalProductsList) {
            if (!doesProductsChanged) {
                for (Product cartProduct : cart.getCartProducts()) {
                    if (originalProduct.getId() == cartProduct.getId()) {
                        if (originalProduct.getPivot().getProductCount() != cartProduct.getCount()) {
                            doesProductsChanged = true;
                            // cart has been changed -> break from inner loop
                            break;
                        }
                    } else {
                        doesProductsChanged = false;
                    }
                }
            } else {
                // cart is already changed -> break from first loop
                break;
            }
        }
    } else {
        // some products has been added or removed (simplest case of Change)
        return true;
    }
    return doesProductsChanged;
}

What is the difference between SQL and MySQL?

SQL is the actual language that as defined by the ISO and ANSI. Here is a link to the Wikipedia article. MySQL is a specific implementation of this standard. I believe Oracle bought the company that originally developed MySQL. Other companies also have their own implementations of the SQL standard.

in iPhone App How to detect the screen resolution of the device

UIScreen class lets you find screen resolution in Points and Pixels.

Screen resolutions is measured in Points or Pixels. It should never be confused with screen size. A smaller screen size can have higher resolution.

UIScreen's 'bounds.width' return rectangular size in Points enter image description here

UIScreen's 'nativeBounds.width' return rectangular size in Pixels.This value is detected as PPI ( Point per inch ). Shows the sharpness & clarity of the Image on a device. enter image description here

You can use UIScreen class to detect all these values.

Swift3

// Normal Screen Bounds - Detect Screen size in Points.
let width = UIScreen.main.bounds.width
let height = UIScreen.main.bounds.height
print("\n width:\(width) \n height:\(height)")

// Native Bounds - Detect Screen size in Pixels.
let nWidth = UIScreen.main.nativeBounds.width
let nHeight = UIScreen.main.nativeBounds.height
print("\n Native Width:\(nWidth) \n Native Height:\(nHeight)")

Console

width:736.0 
height:414.0

Native Width:1080.0 
Native Height:1920.0

Swift 2.x

//Normal Bounds - Detect Screen size in Points.
    let width  = UIScreen.mainScreen.bounds.width
    let height = UIScreen.mainScreen.bounds.height

// Native Bounds - Detect Screen size in Pixels.
    let nWidth  = UIScreen.mainScreen.nativeBounds.width
    let nHeight = UIScreen.mainScreen.nativeBounds.height

ObjectiveC

// Normal Bounds - Detect Screen size in Points.
CGFloat *width  = [UIScreen mainScreen].bounds.size.width;
CGFloat *height = [UIScreen mainScreen].bounds.size.height;

// Native Bounds - Detect Screen size in Pixels.
CGFloat *width  = [UIScreen mainScreen].nativeBounds.size.width
CGFloat *height = [UIScreen mainScreen].nativeBounds.size.width

How can I keep Bootstrap popovers alive while being hovered?

This is my code for show dynamics tooltips with delay and loaded by ajax.

_x000D_
_x000D_
$(window).on('load', function () {_x000D_
    generatePopovers();_x000D_
    _x000D_
    $.fn.dataTable.tables({ visible: true, api: true }).on('draw.dt', function () {_x000D_
        generatePopovers();_x000D_
    });_x000D_
});_x000D_
_x000D_
$(document).ajaxStop(function () {_x000D_
    generatePopovers();_x000D_
});
_x000D_
_x000D_
_x000D_

_x000D_
_x000D_
function generatePopovers() {_x000D_
var popover = $('a[href*="../Something.aspx"]'); //locate the elements to popover_x000D_
_x000D_
popover.each(function (index) {_x000D_
    var poplink = $(this);_x000D_
    if (poplink.attr("data-toggle") == null) {_x000D_
        console.log("RENDER POPOVER: " + poplink.attr('href'));_x000D_
        poplink.attr("data-toggle", "popover");_x000D_
        poplink.attr("data-html", "true");_x000D_
        poplink.attr("data-placement", "top");_x000D_
        poplink.attr("data-content", "Loading...");_x000D_
        poplink.popover({_x000D_
            animation: false,_x000D_
            html: true,_x000D_
            trigger: 'manual',_x000D_
            container: 'body',_x000D_
            placement: 'top'_x000D_
        }).on("mouseenter", function () {_x000D_
            var thispoplink = poplink;_x000D_
            setTimeout(function () {_x000D_
                if (thispoplink.is(":hover")) {_x000D_
                    thispoplink.popover("show");_x000D_
                    loadDynamicData(thispoplink); //load data by ajax if you want_x000D_
                    $('body .popover').on("mouseleave", function () {_x000D_
                        thispoplink.popover('hide');_x000D_
                    });_x000D_
                }_x000D_
            }, 1000);_x000D_
        }).on("mouseleave", function () {_x000D_
            var thispoplink = poplink;_x000D_
            setTimeout(function () {_x000D_
                if (!$("body").find(".popover:hover").length) {_x000D_
                    thispoplink.popover("hide");_x000D_
                }_x000D_
            }, 100);_x000D_
        });_x000D_
    }_x000D_
});
_x000D_
_x000D_
_x000D_

_x000D_
_x000D_
function loadDynamicData(popover) {_x000D_
    var params = new Object();_x000D_
    params.somedata = popover.attr("href").split("somedata=")[1]; //obtain a parameter to send_x000D_
    params = JSON.stringify(params);_x000D_
    //check if the content is not seted_x000D_
    if (popover.attr("data-content") == "Loading...") {_x000D_
        $.ajax({_x000D_
            type: "POST",_x000D_
            url: "../Default.aspx/ObtainData",_x000D_
            data: params,_x000D_
            contentType: "application/json; charset=utf-8",_x000D_
            dataType: 'json',_x000D_
            success: function (data) {_x000D_
                console.log(JSON.parse(data.d));_x000D_
                var dato = JSON.parse(data.d);_x000D_
                if (dato != null) {_x000D_
                    popover.attr("data-content",dato.something); // here you can set the data returned_x000D_
                    if (popover.is(":hover")) {_x000D_
                        popover.popover("show"); //use this for reload the view_x000D_
                    }_x000D_
                }_x000D_
            },_x000D_
_x000D_
            failure: function (data) {_x000D_
                itShowError("- Error AJAX.<br>");_x000D_
            }_x000D_
        });_x000D_
    }_x000D_
}
_x000D_
_x000D_
_x000D_

find filenames NOT ending in specific extensions on Unix?

Linux/OS X:

Starting from the current directory, recursively find all files ending in .dll or .exe

find . -type f | grep -P "\.dll$|\.exe$"

Starting from the current directory, recursively find all files that DON'T end in .dll or .exe

find . -type f | grep -vP "\.dll$|\.exe$"

Notes:

(1) The P option in grep indicates that we are using the Perl style to write our regular expressions to be used in conjunction with the grep command. For the purpose of excecuting the grep command in conjunction with regular expressions, I find that the Perl style is the most powerful style around.

(2) The v option in grep instructs the shell to exclude any file that satisfies the regular expression

(3) The $ character at the end of say ".dll$" is a delimiter control character that tells the shell that the filename string ends with ".dll"

Taking the record with the max date

Justin Cave answer is the best, but if you want antoher option, try this:

select A,col_date
from (select A,col_date
    from tablename 
      order by col_date desc)
      where rownum<2

How do I perform an insert and return inserted identity with Dapper?

A late answer, but here is an alternative to the SCOPE_IDENTITY() answers that we ended up using: OUTPUT INSERTED

Return only ID of inserted object:

It allows you to get all or some attributes of the inserted row:

string insertUserSql = @"INSERT INTO dbo.[User](Username, Phone, Email)
                        OUTPUT INSERTED.[Id]
                        VALUES(@Username, @Phone, @Email);";

int newUserId = conn.QuerySingle<int>(
                                insertUserSql,
                                new
                                {
                                    Username = "lorem ipsum",
                                    Phone = "555-123",
                                    Email = "lorem ipsum"
                                },
                                tran);

Return inserted object with ID:

If you wanted you could get Phone and Email or even the whole inserted row:

string insertUserSql = @"INSERT INTO dbo.[User](Username, Phone, Email)
                        OUTPUT INSERTED.*
                        VALUES(@Username, @Phone, @Email);";

User newUser = conn.QuerySingle<User>(
                                insertUserSql,
                                new
                                {
                                    Username = "lorem ipsum",
                                    Phone = "555-123",
                                    Email = "lorem ipsum"
                                },
                                tran);

Also, with this you can return data of deleted or updated rows. Just be careful if you are using triggers because (from link mentioned before):

Columns returned from OUTPUT reflect the data as it is after the INSERT, UPDATE, or DELETE statement has completed but before triggers are executed.

For INSTEAD OF triggers, the returned results are generated as if the INSERT, UPDATE, or DELETE had actually occurred, even if no modifications take place as the result of the trigger operation. If a statement that includes an OUTPUT clause is used inside the body of a trigger, table aliases must be used to reference the trigger inserted and deleted tables to avoid duplicating column references with the INSERTED and DELETED tables associated with OUTPUT.

More on it in the docs: link

How to count down in for loop?

In python, when you have an iterable, usually you iterate without an index:

letters = 'abcdef' # or a list, tupple or other iterable
for l in letters:
    print(l)

If you need to traverse the iterable in reverse order, you would do:

for l in letters[::-1]:
    print(l)

When for any reason you need the index, you can use enumerate:

for i, l in enumerate(letters, start=1): #start is 0 by default
    print(i,l)

You can enumerate in reverse order too...

for i, l in enumerate(letters[::-1])
    print(i,l)

ON ANOTHER NOTE...

Usually when we traverse an iterable we do it to apply the same procedure or function to each element. In these cases, it is better to use map:

If we need to capitilize each letter:

map(str.upper, letters)

Or get the Unicode code of each letter:

map(ord, letters)

Best data type to store money values in MySQL

If your application needs to handle money values up to a trillion then this should work: 13,2 If you need to comply with GAAP (Generally Accepted Accounting Principles) then use: 13,4

Usually you should sum your money values at 13,4 before rounding of the output to 13,2.

How do I disable the security certificate check in Python requests

If you are writing a scraper and really don't care about the SSL certificate you can set it global:

import ssl

ssl._create_default_https_context = ssl._create_unverified_context

DO NOT USE IN PRODUCTION

Setting the correct encoding when piping stdout in Python

Your code works when run in an script because Python encodes the output to whatever encoding your terminal application is using. If you are piping you must encode it yourself.

A rule of thumb is: Always use Unicode internally. Decode what you receive, and encode what you send.

# -*- coding: utf-8 -*-
print u"åäö".encode('utf-8')

Another didactic example is a Python program to convert between ISO-8859-1 and UTF-8, making everything uppercase in between.

import sys
for line in sys.stdin:
    # Decode what you receive:
    line = line.decode('iso8859-1')

    # Work with Unicode internally:
    line = line.upper()

    # Encode what you send:
    line = line.encode('utf-8')
    sys.stdout.write(line)

Setting the system default encoding is a bad idea, because some modules and libraries you use can rely on the fact it is ASCII. Don't do it.

How to set Angular 4 background image?

You can use ngStyle to set background for a div

<div [ngStyle]="{background-image: 'url(./images/' + trls.img + ')'}"></div>

or you can also use built in background style:

<div [style.background-image]="'url(/images/' + trls.img + ')'"></div>

How to reset index in a pandas dataframe?

Another solutions are assign RangeIndex or range:

df.index = pd.RangeIndex(len(df.index))

df.index = range(len(df.index))

It is faster:

df = pd.DataFrame({'a':[8,7], 'c':[2,4]}, index=[7,8])
df = pd.concat([df]*10000)
print (df.head())

In [298]: %timeit df1 = df.reset_index(drop=True)
The slowest run took 7.26 times longer than the fastest. This could mean that an intermediate result is being cached.
10000 loops, best of 3: 105 µs per loop

In [299]: %timeit df.index = pd.RangeIndex(len(df.index))
The slowest run took 15.05 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 7.84 µs per loop

In [300]: %timeit df.index = range(len(df.index))
The slowest run took 7.10 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 14.2 µs per loop

Set a button background image iPhone programmatically

This will work

UIImage *buttonImage = [UIImage imageNamed:@"imageName.png"];
[btn setImage:buttonImage forState:UIControlStateNormal];
[self.view addSubview:btn];

Clear data in MySQL table with PHP?

TRUNCATE TABLE tablename

or

DELETE FROM tablename

The first one is usually the better choice, as DELETE FROM is slow on InnoDB.

Actually, wasn't this already answered in your other question?

PHP - Get key name of array value

key($arr);

will return the key value for the current array element

http://uk.php.net/manual/en/function.key.php

Twitter Bootstrap modal on mobile devices

The solution by niftylettuce in issue 2130 seems to fix modals in all mobile platforms...

9/1/12 UPDATE: The fix has been updated here: twitter bootstrap jquery plugins

(the code below is older but still works)

// # Twitter Bootstrap modal responsive fix by @niftylettuce
//  * resolves #407, #1017, #1339, #2130, #3361, #3362, #4283
//   <https://github.com/twitter/bootstrap/issues/2130>
//  * built-in support for fullscreen Bootstrap Image Gallery
//    <https://github.com/blueimp/Bootstrap-Image-Gallery>

// **NOTE:** If you are using .modal-fullscreen, you will need
//  to add the following CSS to `bootstrap-image-gallery.css`:
//
//  @media (max-width: 480px) {
//    .modal-fullscreen {
//      left: 0 !important;
//      right: 0 !important;
//      margin-top: 0 !important;
//      margin-left: 0 !important;
//    }
//  }
//

var adjustModal = function($modal) {
  var top;
  if ($(window).width() <= 480) {
    if ($modal.hasClass('modal-fullscreen')) {
      if ($modal.height() >= $(window).height()) {
        top = $(window).scrollTop();
      } else {
        top = $(window).scrollTop() + ($(window).height() - $modal.height()) / 2;
      }
    } else if ($modal.height() >= $(window).height() - 10) {
      top = $(window).scrollTop() + 10;
    } else {
      top = $(window).scrollTop() + ($(window).height() - $modal.height()) / 2;
    }
  } else {
    top = '50%';
    if ($modal.hasClass('modal-fullscreen')) {
      $modal.stop().animate({
          marginTop  : -($modal.outerHeight() / 2)
        , marginLeft : -($modal.outerWidth() / 2)
        , top        : top
      }, "fast");
      return;
    }
  }
  $modal.stop().animate({ 'top': top }, "fast");
};

var show = function() {
  var $modal = $(this);
  adjustModal($modal);
};

var checkShow = function() {
  $('.modal').each(function() {
    var $modal = $(this);
    if ($modal.css('display') !== 'block') return;
    adjustModal($modal);
  });
};

var modalWindowResize = function() {
  $('.modal').not('.modal-gallery').on('show', show);
  $('.modal-gallery').on('displayed', show);
  checkShow();
};

$(modalWindowResize);
$(window).resize(modalWindowResize);
$(window).scroll(checkShow);

OSError: [Errno 8] Exec format error

I will hijack this thread to point out that this error may also happen when target of Popen is not executable. Learnt it hard way when by accident I have had override a perfectly executable binary file with zip file.

Java unsupported major minor version 52.0

Your code was compiled with Java Version 1.8 while it is being executed with Java Version 1.7 or below.

In your case it seems that two different Java installations are used, the newer to compile and the older to execute your code.

Try recompiling your code with Java 1.7 or upgrade your Java Plugin.

Execute a stored procedure in another stored procedure in SQL server

Your sp_test: Return fullname

USE [MY_DB]
GO

IF (OBJECT_ID('[dbo].[sp_test]', 'P') IS NOT NULL)
DROP PROCEDURE [dbo].sp_test;
GO

CREATE PROCEDURE [dbo].sp_test 
@name VARCHAR(20),
@last_name VARCHAR(30),
@full_name VARCHAR(50) OUTPUT
AS

SET @full_name = @name + @last_name;

GO

In your sp_main

...
DECLARE @my_name VARCHAR(20);
DECLARE @my_last_name VARCHAR(30);
DECLARE @my_full_name VARCHAR(50);
...

EXEC sp_test @my_name, @my_last_name, @my_full_name OUTPUT;
...

Kotlin - How to correctly concatenate a String

yourString += "newString"

This way you can concatenate a string

INNER JOIN same table

I don't know how the table is created but try this...

SELECT users1.user_id, users2.user_parent_id
FROM users AS users1
INNER JOIN users AS users2
ON users1.id = users2.id
WHERE users1.user_id = users2.user_parent_id

How do you produce a .d.ts "typings" definition file from an existing JavaScript library?

When creating your own library, you can can create *.d.ts files by using the tsc (TypeScript Compiler) command like so: (assuming you're building your library to the dist/lib folder)

tsc -d --declarationDir dist/lib --declarationMap --emitDeclarationOnly
  • -d (--declaration): generates the *.d.ts files
  • --declarationDir dist/lib: Output directory for generated declaration files.
  • --declarationMap: Generates a sourcemap for each corresponding ‘.d.ts’ file.
  • --emitDeclarationOnly: Only emit ‘.d.ts’ declaration files. (no compiled JS)

(see the docs for all command line compiler options)

Or for instance in your package.json:

"scripts": {
    "build:types": "tsc -d --declarationDir dist/lib --declarationMap --emitDeclarationOnly",
}

and then run: yarn build:types (or npm run build:types)

Nested jQuery.each() - continue/break

You should do this without jQuery, it may not be as "pretty" but there's less going on and it's easier to do exactly what you want, like this:

var sentences = [
    'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
    'Vivamus aliquet nisl quis velit ornare tempor.',
    'Cras sit amet neque ante, eu ultrices est.',
    'Integer id lectus id nunc venenatis gravida nec eget dolor.',
    'Suspendisse imperdiet turpis ut justo ultricies a aliquet tortor ultrices.'
];

var words = ['ipsum', 'amet', 'elit'];

for(var s=0; s<sentences.length; s++) {
    alert(sentences[s]);
    for(var w=0; w<words.length; w++) {
        if(sentences[s].indexOf(words[w]) > -1) {
            alert('found ' + words[w]);
            return;
        }
    }
}

You can try it out here. I'm not sure if this is the exact behavior you're after, but now you're not in a closure inside a closure created by the double .each() and you can return or break whenever you want in this case.

How to disable keypad popup when on edittext?

For Xamarin Users:

[Activity(MainLauncher = true, 
        ScreenOrientation = ScreenOrientation.Portrait, 
        WindowSoftInputMode = SoftInput.StateHidden)] //SoftInput.StateHidden - disables keyboard autopop

Using HTTPS with REST in Java

Something to keep in mind is that this error isn't only due to self signed certs. The new Entrust CA certs fail with the same error, and the right thing to do is to update the server with the appropriate root certs, not to disable this important security feature.

How to center align the cells of a UICollectionView?

Here is my solution with a few assumptions:

  • there is only one section
  • left and right insets are equal
  • cell height is the same

Feel free to adjust to meet your needs.

Centered layout with variable cell width:

protocol HACenteredLayoutDelegate: UICollectionViewDataSource {
    func getCollectionView() -> UICollectionView
    func sizeOfCell(at index: IndexPath) -> CGSize
    func contentInsets() -> UIEdgeInsets
}

class HACenteredLayout: UICollectionViewFlowLayout {
    weak var delegate: HACenteredLayoutDelegate?
    private var cache = [UICollectionViewLayoutAttributes]()
    private var contentSize = CGSize.zero
    override var collectionViewContentSize: CGSize { return self.contentSize }

    required init(delegate: HACenteredLayoutDelegate) {
        self.delegate = delegate
        super.init()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    override func invalidateLayout() {
        cache.removeAll()
        super.invalidateLayout()
    }

    override func prepare() {
        if cache.isEmpty && self.delegate != nil && self.delegate!.collectionView(self.delegate!.getCollectionView(), numberOfItemsInSection: 0) > 0 {
            let insets = self.delegate?.contentInsets() ?? UIEdgeInsets.zero
            var rows: [(width: CGFloat, count: Int)] = [(0, 0)]
            let viewWidth: CGFloat = UIScreen.main.bounds.width
            var y = insets.top
            var unmodifiedIndexes = [IndexPath]()
            for itemNumber in 0 ..< self.delegate!.collectionView(self.delegate!.getCollectionView(), numberOfItemsInSection: 0) {
                let indexPath = IndexPath(item: itemNumber, section: 0)
                let cellSize = self.delegate!.sizeOfCell(at: indexPath)
                let potentialRowWidth = rows.last!.width + (rows.last!.count > 0 ? self.minimumInteritemSpacing : 0) + cellSize.width + insets.right + insets.left
                if potentialRowWidth > viewWidth {
                    let leftOverSpace = max((viewWidth - rows[rows.count - 1].width)/2, insets.left)
                    for i in unmodifiedIndexes {
                        self.cache[i.item].frame.origin.x += leftOverSpace
                    }
                    unmodifiedIndexes = []
                    rows.append((0, 0))
                    y += cellSize.height + self.minimumLineSpacing
                }
                unmodifiedIndexes.append(indexPath)
                let attribute = UICollectionViewLayoutAttributes(forCellWith: indexPath)
                rows[rows.count - 1].count += 1
                rows[rows.count - 1].width += rows[rows.count - 1].count > 1 ? self.minimumInteritemSpacing : 0
                attribute.frame = CGRect(x: rows[rows.count - 1].width, y: y, width: cellSize.width, height: cellSize.height)
                rows[rows.count - 1].width += cellSize.width
                cache.append(attribute)
            }
            let leftOverSpace = max((viewWidth - rows[rows.count - 1].width)/2, insets.left)
            for i in unmodifiedIndexes {
                self.cache[i.item].frame.origin.x += leftOverSpace
            }
            self.contentSize = CGSize(width: viewWidth, height: y + self.delegate!.sizeOfCell(at: IndexPath(item: 0, section: 0)).height + insets.bottom)
        }
    }

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        var layoutAttributes = [UICollectionViewLayoutAttributes]()

        for attributes in cache {
            if attributes.frame.intersects(rect) {
                layoutAttributes.append(attributes)
            }
        }
        return layoutAttributes
    }

    override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
        if indexPath.item < self.cache.count {
            return self.cache[indexPath.item]
        }
        return nil
    }
}

Result:

enter image description here

Convert string to BigDecimal in java

BigDecimal b = BigDecimal.valueOf(d);

import java.math.*; 

public class Test { 

    public static void main(String[] args) 
    { 

        // Creating a Double Object 
        Double d = new Double("785.254"); 

        /// Assigning the bigdecimal value of ln to b 
        BigDecimal b = BigDecimal.valueOf(d); 

        // Displaying BigDecimal value 
        System.out.println("The Converted BigDecimal value is: " + b); 
    } 
}

How to replace a set of tokens in a Java String?

System.out.println(MessageFormat.format("Hello {0}! You have {1} messages", "Join",10L));

Output: Hello Join! You have 10 messages"

What is an MDF file?

Just to make this absolutely clear for all:

A .MDF file is “typically” a SQL Server data file however it is important to note that it does NOT have to be.

This is because .MDF is nothing more than a recommended/preferred notation but the extension itself does not actually dictate the file type.

To illustrate this, if someone wanted to create their primary data file with an extension of .gbn they could go ahead and do so without issue.

To qualify the preferred naming conventions:

  • .mdf - Primary database data file.
  • .ndf - Other database data files i.e. non Primary.
  • .ldf - Log data file.

What does \0 stand for?

In C \0 is a character literal constant store into an int data type that represent the character with value of 0.

Since Objective-C is a strict superset of C this constant is retained.

Switch case in C# - a constant value is expected

Johnnie, Please go through msdn guide on switch. Also, the C# language specification clearly defines the compile time error case:

• If the type of the switch expression is sbyte, byte, short, ushort, int, uint, long, ulong, bool, char, string, or an enum-type, or if it is the nullable type corresponding to one of these types, then that is the governing type of the switch statement.

• Otherwise, exactly one user-defined implicit conversion (§6.4) must exist from the type of the switch expression to one of the following possible governing types: sbyte, byte, short, ushort, int, uint, long, ulong, char, string, or, a nullable type corresponding to one of those types.

• Otherwise, if no such implicit conversion exists, or if more than one such implicit conversion exists, a compile-time error occurs.

Hope this helps.

WSDL vs REST Pros and Cons

REST is not a protocol; It's an architectural style. Or a paradigm if you want. That means that it's a lot looser defined that SOAP is. For basic CRUD, you can lean on standard protocols such as Atompub, but for most services you'll have more commands than just that.

As a consumer, SOAP can be a blessing or a curse, depending on the language support. Since SOAP is very much modelled on a strictly typed system, it works best with statically typed languages. For a dynamic language it can easily become crufty and superfluous. In addition, the client-library support isn't that good outside the world of Java and .NET

How to make a <svg> element expand or contract to its parent container?

Suppose I have an SVG which looks like this: pic1

And I want to put it in a div and make it fill the div responsively. My way of doing it is as follows:

First I open the SVG file in an application like inkscape. In File->Document Properties I set the width of the document to 800px and and the height to 600px (you can choose other sizes). Then I fit the SVG into this document.

pic2

Then I save this file as a new SVG file and get the path data from this file. Now in HTML the code that does the magic is as follows:

<div id="containerId">    
    <svg
    id="svgId" 
    xmlns:svg="http://www.w3.org/2000/svg"
    xmlns="http://www.w3.org/2000/svg"
    version="1.1"
    x="0"
    y="0"
    width="100%"
    height="100%"
    viewBox="0 0 800 600"
    preserveAspectRatio="none">
       <path d="m0 0v600h800v-600h-75.07031l-431 597.9707-292.445315-223.99609 269.548825-373.97461h-271.0332z" fill="#f00"/>
    </svg>
</div>

Note that width and height of SVG are both set to 100%, since we want it to fill the container vertically and horizontally ,but width and height of the viewBox are the same as the width and height of the document in inkscape which is 800px X 600px. The next thing you need to do is set the preserveAspectRatio to "none". If you need to have more information on this attribute here's a good link. And that's all there is to it.

One more thing is that this code works on almost all the major browsers even the old ones but on some versions of android and ios you need to use some javascrip/jQuery code to keep it consistent. I use the following in document ready and resize functions:

$('#svgId').css({
    'width': $('#containerId').width() + 'px',
    'height': $('#containerId').height() + 'px'
});

Hope it helps!

if variable contains

The fastest way to check if a string contains another string is using indexOf:

if (code.indexOf('ST1') !== -1) {
    // string code has "ST1" in it
} else {
    // string code does not have "ST1" in it
}

Tomcat is web server or application server?

Apache Tomcat is an open source software implementation of the Java Servlet and JavaServer Pages technologies.

Since Tomcat does not implement the full Java EE specification for an application server, it can be considered as a web server.

Source: http://tomcat.apache.org

Export data from R to Excel

writexl, without Java requirement:

# install.packages("writexl")
library(writexl)
tempfile <- write_xlsx(iris)

Get name of currently executing test in JUnit 4

Based on the previous comment and further considering I created an extension of TestWather which you can use in your JUnit test methods with this:

public class ImportUtilsTest {
    private static final Logger LOGGER = Logger.getLogger(ImportUtilsTest.class);

    @Rule
    public TestWatcher testWatcher = new JUnitHelper(LOGGER);

    @Test
    public test1(){
    ...
    }
}

The test helper class is the next:

public class JUnitHelper extends TestWatcher {
private Logger LOGGER;

public JUnitHelper(Logger LOGGER) {
    this.LOGGER = LOGGER;
}

@Override
protected void starting(final Description description) {
    LOGGER.info("STARTED " + description.getMethodName());
}

@Override
protected void succeeded(Description description) {
    LOGGER.info("SUCCESSFUL " + description.getMethodName());
}

@Override
protected void failed(Throwable e, Description description) {
    LOGGER.error("FAILURE " + description.getMethodName());
}
}

Enjoy!

How to set Default Controller in asp.net MVC 4 & MVC 5

In case you have only one controller and you want to access every action on root you can skip controller name like this

routes.MapRoute(
        "Default", 
        "{action}/{id}", 
        new { controller = "Home", action = "Index", 
        id = UrlParameter.Optional }
);

How to show live preview in a small popup of linked page on mouse over on link?

You can display a live preview of a link using javascript using the code below.

_x000D_
_x000D_
<embed src="https://www.w3schools.com/html/default.asp" width="60" height="40" />_x000D_
<p id="p1"><a href="http://cnet.com">Cnet</a></p>_x000D_
<p id="p2"><a href="http://codegena.com">Codegena</a></p>_x000D_
<p id="p3"><a href="http://apple.com">Apple</a></p>_x000D_
_x000D_
_x000D_
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>_x000D_
  <link href="http://codegena.com/assets/css/image-preview-for-link.css" rel="stylesheet">     _x000D_
  <script type="text/javascript">_x000D_
    $(function() {_x000D_
                $('#p1 a').miniPreview({ prefetch: 'pageload' });_x000D_
                $('#p2 a').miniPreview({ prefetch: 'parenthover' });_x000D_
                $('#p3 a').miniPreview({ prefetch: 'none' });_x000D_
            });_x000D_
  </script> <script src="http://codegena.com/assets/js/image-preview-for-link.js"></script>
_x000D_
_x000D_
_x000D_

Learn more about it at Codegena

id="p1" - Fetch image preview on page load.
id="p2" - Fetch preview on hover.
id="p3" - Fetch preview image each time you hover.

Jquery $(this) Child Selector

This is a lot simpler with .slideToggle():

jQuery('.class1 a').click( function() {
  $(this).next('.class2').slideToggle();
});

EDIT: made it .next instead of .siblings

http://www.mredesign.com/demos/jquery-effects-1/

You can also add cookie's to remember where you're at...

http://c.hadcoleman.com/2008/09/jquery-slide-toggle-with-cookie/

T-test in Pandas

it depends what sort of t-test you want to do (one sided or two sided dependent or independent) but it should be as simple as:

from scipy.stats import ttest_ind

cat1 = my_data[my_data['Category']=='cat1']
cat2 = my_data[my_data['Category']=='cat2']

ttest_ind(cat1['values'], cat2['values'])
>>> (1.4927289925706944, 0.16970867501294376)

it returns a tuple with the t-statistic & the p-value

see here for other t-tests http://docs.scipy.org/doc/scipy/reference/stats.html

Function not defined javascript

I just went through the same problem. And found out once you have a syntax or any type of error in you javascript, the whole file don't get loaded so you cannot use any of the other functions at all.

How to generate auto increment field in select query

DECLARE @id INT 
SET @id = 0 
UPDATE cartemp
SET @id = CarmasterID = @id + 1 
GO

Click in OK button inside an Alert (Selenium IDE)

Use chooseOkOnNextConfirmation() to dismiss the alert and getAlert() to verify that it has been shown (and optionally grab its text for verification).

selenium.chooseOkOnNextConfirmation();  // prepares Selenium to handle next alert
selenium.click(locator);
String alertText = selenium.getAlert(); // verifies that alert was shown
assertEquals("This is a popup window", alertText);
...

How can I suppress all output from a command using Bash?

Something like

script > /dev/null 2>&1

This will prevent standard output and error output, redirecting them both to /dev/null.

Unsigned keyword in C++

You can read about the keyword unsigned in the C++ Reference.

There are two different types in this matter, signed and un-signed. The default for integers is signed which means that they can have negative values.

On a 32-bit system an integer is 32 Bit which means it can contain a value of ~4 billion.

And when it is signed, this means you need to split it, leaving -2 billion to +2 billion.

When it is unsigned however the value cannot contain any negative numbers, so for integers this would mean 0 to +4 billion.

There is a bit more informationa bout this on Wikipedia.

Apache shutdown unexpectedly

It means port 80 is already used by another one.

Simply follow these steps:

  1. Open windows -> click on Run (win + R) -> type services.msc
  2. Goto IIS Admin -> Right click on it and click on Stop Option.
  3. Open XAMPP click on Start Action of Apache Module, Apache Module is run.

OR

For find the port of Apache (80) in Command Prompt simply type netstat -aon it displays present used ports on windows, under Local Address column it shown as 0.0.0.0:80. If it displays this port another connection is already used this port number.

Active Connections in Windows XP:

Active Connections in Windows XP

I solved my problem after installing xampp-win32-1.6.5-installer previously I used xampp version xampp-win32-1.8.2-0-VC9-installer at that time I got this error. Now it resolved my problem.

How can I divide one column of a data frame through another?

There are a plethora of ways in which this can be done. The problem is how to make R aware of the locations of the variables you wish to divide.

Assuming

d <- read.table(text = "263807.0    1582
196190.5    1016
586689.0    3479
")
names(d) <- c("min", "count2.freq")
> d
       min count2.freq
1 263807.0        1582
2 196190.5        1016
3 586689.0        3479

My preferred way

To add the desired division as a third variable I would use transform()

> d <- transform(d, new = min / count2.freq)
> d
       min count2.freq      new
1 263807.0        1582 166.7554
2 196190.5        1016 193.1009
3 586689.0        3479 168.6373

The basic R way

If doing this in a function (i.e. you are programming) then best to avoid the sugar shown above and index. In that case any of these would do what you want

## 1. via `[` and character indexes
d[, "new"] <- d[, "min"] / d[, "count2.freq"]

## 2. via `[` with numeric indices
d[, 3] <- d[, 1] / d[, 2]

## 3. via `$`
d$new <- d$min / d$count2.freq

All of these can be used at the prompt too, but which is easier to read:

d <- transform(d, new = min / count2.freq)

or

d$new <- d$min / d$count2.freq ## or any of the above examples

Hopefully you think like I do and the first version is better ;-)

The reason we don't use the syntactic sugar of tranform() et al when programming is because of how they do their evaluation (look for the named variables). At the top level (at the prompt, working interactively) transform() et al work just fine. But buried in function calls or within a call to one of the apply() family of functions they can and often do break.

Likewise, be careful using numeric indices (## 2. above); if you change the ordering of your data, you will select the wrong variables.

The preferred way if you don't need replacement

If you are just wanting to do the division (rather than insert the result back into the data frame, then use with(), which allows us to isolate the simple expression you wish to evaluate

> with(d, min / count2.freq)
[1] 166.7554 193.1009 168.6373

This is again much cleaner code than the equivalent

> d$min / d$count2.freq
[1] 166.7554 193.1009 168.6373

as it explicitly states that "using d, execute the code min / count2.freq. Your preference may be different to mine, so I have shown all options.

How to round each item in a list of floats to 2 decimal places?

You might want to look at Python's decimal module, which can make using floating point numbers and doing arithmetic with them a lot more intuitive. Here's a trivial example of one way of using it to "clean up" your list values:

>>> from decimal import *
>>> mylist = [0.30000000000000004, 0.5, 0.20000000000000001]
>>> getcontext().prec = 2
>>> ["%.2f" % e for e in mylist]
['0.30', '0.50', '0.20']
>>> [Decimal("%.2f" % e) for e in mylist]
[Decimal('0.30'), Decimal('0.50'), Decimal('0.20')]
>>> data = [float(Decimal("%.2f" % e)) for e in mylist]
>>> data
[0.3, 0.5, 0.2]

Non-conformable arrays error in code

The problem is that omega in your case is matrix of dimensions 1 * 1. You should convert it to a vector if you wish to multiply t(X) %*% X by a scalar (that is omega)

In particular, you'll have to replace this line:

omega   = rgamma(1,a0,1) / L0

with:

omega   = as.vector(rgamma(1,a0,1) / L0)

everywhere in your code. It happens in two places (once inside the loop and once outside). You can substitute as.vector(.) or c(t(.)). Both are equivalent.

Here's the modified code that should work:

gibbs = function(data, m01 = 0, m02 = 0, k01 = 0.1, k02 = 0.1, 
                     a0 = 0.1, L0 = 0.1, nburn = 0, ndraw = 5000) {
    m0      = c(m01, m02) 
    C0      = matrix(nrow = 2, ncol = 2) 
    C0[1,1] = 1 / k01 
    C0[1,2] = 0 
    C0[2,1] = 0 
    C0[2,2] = 1 / k02 
    beta    = mvrnorm(1,m0,C0) 
    omega   = as.vector(rgamma(1,a0,1) / L0)
    draws   = matrix(ncol = 3,nrow = ndraw) 
    it      = -nburn 

    while (it < ndraw) {
        it    = it + 1 
        C1    = solve(solve(C0) + omega * t(X) %*% X) 
        m1    = C1 %*% (solve(C0) %*% m0 + omega * t(X) %*% y)
        beta  = mvrnorm(1, m1, C1) 
        a1    = a0 + n / 2 
        L1    = L0 + t(y - X %*% beta) %*% (y - X %*% beta) / 2 
        omega = as.vector(rgamma(1, a1, 1) / L1)
        if (it > 0) { 
            draws[it,1] = beta[1]
            draws[it,2] = beta[2]
            draws[it,3] = omega
        }
    }
    return(draws)
}

How to get current time with jQuery

You don't need to use jQuery for this!

The native JavaScript implementation is Date.now().

Date.now() and $.now() return the same value:

Date.now(); // 1421715573651
$.now();    // 1421715573651
new Date(Date.now())   // Mon Jan 19 2015 20:02:55 GMT-0500 (Eastern Standard Time)
new Date($.now());     // Mon Jan 19 2015 20:02:55 GMT-0500 (Eastern Standard Time)

..and if you want the time formatted in hh-mm-ss:

var now = new Date(Date.now());
var formatted = now.getHours() + ":" + now.getMinutes() + ":" + now.getSeconds();
// 20:10:58

Changing route doesn't scroll to top in the new page

Using angularjs UI Router, what I'm doing is this:

    .state('myState', {
        url: '/myState',
        templateUrl: 'app/views/myState.html',
        onEnter: scrollContent
    })

With:

var scrollContent = function() {
    // Your favorite scroll method here
};

It never fails on any page, and it is not global.

Mailto on submit button

Just include "a" tag in "button" tag.

<button><a href="mailto:..."></a></button>

What is the difference between an int and a long in C++?

It depends on your compiler. You are guaranteed that a long will be at least as large as an int, but you are not guaranteed that it will be any longer.

When do you use the "this" keyword?

I use it when, in a function that accepts a reference to an object of the same type, I want to make it perfectly clear which object I'm referring to, where.

For example

class AABB
{
  // ... members
  bool intersects( AABB other )
  {
    return other.left() < this->right() &&
           this->left() < other.right() &&

           // +y increases going down
           other.top() < this->bottom() &&
           this->top() < other.bottom() ;
  }
} ;

(vs)

class AABB
{
  bool intersects( AABB other )
  {
    return other.left() < right() &&
           left() < other.right() &&

           // +y increases going down
           other.top() < bottom() &&
           top() < other.bottom() ;
  }
} ;

At a glance which AABB does right() refer to? The this adds a bit of a clarifier.

HTTP response header content disposition for attachments

Try the Content-Disposition header

Content-Disposition: attachment; filename=<file name.ext> 

cc1plus: error: unrecognized command line option "-std=c++11" with g++

Seeing from your G++ version, you need to update it badly. C++11 has only been available since G++ 4.3. The most recent version is 4.7.

In versions pre-G++ 4.7, you'll have to use -std=c++0x, for more recent versions you can use -std=c++11.

How to support different screen size in android

Beginning with Android 3.2 (API level 13), size groups (folders small, normal, large, xlarge) are deprecated in favor of a new technique for managing screen sizes based on the available screen width.



There are different resource configurations that you can specify based on the space available for your layout:

1) Smallest Width - The fundamental size of a screen, as indicated by the shortest dimension of the available screen area.

Qualifier Value: sw'dp value'dp

Eg. res/sw600dp/layout.xml -> will be used for all screen sizes bigger or equal to 600dp. This does not take the device orientation into account.


2) Available Screen Width - Specifies a minimum available width in dp units at which the resources should be used.

Qualifier Value: w'dp value'dp

Eg. res/w600dp/layout.xml -> will be used for all screens, which width is greater than or equal to 600dp.


3) Available Screen Height - Specifies a minimum screen height in dp units at which the resources should be used.

Qualifier Value: h'dp value'dp

Eg. res/h600dp/layout.xml -> will be used for all screens, which height is greater than or equal to 600dp.



So at the end your folder structure might look like this:

res/layout/layout.xml -> for handsets (smaller than 600dp available width)
res/layout-sw600dp/layout.xml -> for 7” tablets (600dp wide and bigger)
res/layout-sw720dp/layout.xml -> for 10” tablets (720dp wide and bigger)


For more information please read the official documentation:
https://developer.android.com/guide/practices/screens_support.html#DeclaringTabletLayouts

Taking pictures with camera on Android programmatically

Intent takePhoto = new Intent("android.media.action.IMAGE_CAPTURE");
startActivityForResult(takePhoto, CAMERA_PIC_REQUEST)

and set CAMERA_PIC_REQUEST= 1 or 0

How to convert these strange characters? (ë, Ã, ì, ù, Ã)

These are utf-8 encoded characters. Use utf8_decode() to convert them to normal ISO-8859-1 characters.

While variable is not defined - wait

I have upvoted @dnuttle's answer, but ended up using the following strategy:

// On doc ready for modern browsers
document.addEventListener('DOMContentLoaded', (e) => {
  // Scope all logic related to what you want to achieve by using a function
  const waitForMyFunction = () => {
    // Use a timeout id to identify your process and purge it when it's no longer needed
    let timeoutID;
    // Check if your function is defined, in this case by checking its type
    if (typeof myFunction === 'function') {
      // We no longer need to wait, purge the timeout id
      window.clearTimeout(timeoutID);
      // 'myFunction' is defined, invoke it with parameters, if any
      myFunction('param1', 'param2');
    } else {
      // 'myFunction' is undefined, try again in 0.25 secs
      timeoutID = window.setTimeout(waitForMyFunction, 250);
    }
  };
  // Initialize
  waitForMyFunction();
});

It is tested and working! ;)

Gist: https://gist.github.com/dreamyguy/f319f0b2bffb1f812cf8b7cae4abb47c

Try/catch does not seem to have an effect

Edit: As stated in the comments, the following solution applies to PowerShell V1 only.

See this blog post on "Technical Adventures of Adam Weigert" for details on how to implement this.

Example usage (copy/paste from Adam Weigert's blog):

Try {
    echo " ::Do some work..."
    echo " ::Try divide by zero: $(0/0)"
} -Catch {
    echo "  ::Cannot handle the error (will rethrow): $_"
    #throw $_
} -Finally {
    echo " ::Cleanup resources..."
}

Otherwise you'll have to use exception trapping.

Insertion sort vs Bubble Sort Algorithms

well bubble sort is better than insertion sort only when someone is looking for top k elements from a large list of number i.e. in bubble sort after k iterations you'll get top k elements. However after k iterations in insertion sort, it only assures that those k elements are sorted.

LaTeX: remove blank page after a \part or \chapter

I believe that in the book class all \part and \chapter are set to start on a recto page.

from book.cls:

\newcommand\part{%
  \if@openright
    \cleardoublepage
  \else
    \clearpage
  \fi
  \thispagestyle{plain}%
  \if@twocolumn
    \onecolumn
    \@tempswatrue
  \else
    \@tempswafalse
  \fi
  \null\vfil
  \secdef\@part\@spart}

you should be able to renew that command, and something similar for the \chapter.

How do the major C# DI/IoC frameworks compare?

See for a comparison of net-ioc-frameworks on google code including linfu and spring.net that are not on your list while i write this text.

I worked with spring.net: It has many features (aop, libraries , docu, ...) and there is a lot of experience with it in the dotnet and the java-world. The features are modularized so you donot have to take all features. The features are abstractions of common issues like databaseabstraction, loggingabstraction. however it is difficuilt to do and debug the IoC-configuration.

From what i have read so far: If i had to chooseh for a small or medium project i would use ninject since ioc-configuration is done and debuggable in c#. But i havent worked with it yet. for large modular system i would stay with spring.net because of abstraction-libraries.

How can I tell Moq to return a Task?

Similar Issue

I have an interface that looked roughly like:

Task DoSomething(int arg);

Symptoms

My unit test failed when my service under test awaited the call to DoSomething.

Fix

Unlike the accepted answer, you are unable to call .ReturnsAsync() on your Setup() of this method in this scenario, because the method returns the non-generic Task, rather than Task<T>.

However, you are still able to use .Returns(Task.FromResult(default(object))) on the setup, allowing the test to pass.

How to send an email from JavaScript

Since these all are wonderful infos there's a little api called Mandrill to send mails from javascript and it works perfectly. You can give it a shot. Here's a little tutorial for the start.

How to create a QR code reader in a HTML5 website?

There aren't many JavaScript decoders.

There is one at http://www.webqr.com/index.html

The easiest way is to run ZXing or similar on your server. You can then POST the image and get the decoded result back in the response.

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

Your syntax for the target attribute is correct, but browsers need not honor it. They may interpret it as opening the destination in a new tab rather than new window, or they may completely ignore the attribute. Browsers have settings for such issues. Moreover, opening of new windows may be prevented by browser plugins (typically designed to prevent annoying advertisements).

There’s little you can do about this as an author. You might consider opening a new window with JavaScript instead, cf. to the accepted answer to target="_blank" is not working in firefox?, but browsers may be even more reluctant to let pages open new windows that way than via target.

target="_blank" is not working in firefox?

jQuery and TinyMCE: textarea value doesn't submit

First of all:

  1. You must include tinymce jquery plugin in your page (jquery.tinymce.min.js)

  2. One of the simplest and safest ways is to use getContent and setContent with triggerSave. Example:

    tinyMCE.get('editor_id').setContent(tinyMCE.get('editor_id').getContent()+_newdata);
    tinyMCE.triggerSave();
    

Get a list of checked checkboxes in a div using jQuery

function listselect() {
                var selected = [];
                $('.SelectPhone').prop('checked', function () {

                    selected.push($(this).val());
                });

                alert(selected.length);
     <input type="checkbox" name="SelectPhone" class="SelectPhone"  value="1" />
         <input type="checkbox" name="SelectPhone" class="SelectPhone"  value="2" />
         <input type="checkbox" name="SelectPhone" class="SelectPhone"  value="3" />
        <button onclick="listselect()">show count</button>

Are lists thread-safe?

Here's a comprehensive yet non-exhaustive list of examples of list operations and whether or not they are thread safe. Hoping to get an answer regarding the obj in a_list language construct here.

C++ Returning reference to local variable

A local variable is memory on the stack, that memory is not automatically invalidated when you go out of scope. From a Function deeper nested (higher on the stack in memory), its perfectly safe to access this memory.

Once the Function returns and ends though, things get dangerous. Usually the memory is not deleted or overwritten when you return, meaning the memory at that adresss is still containing your data - the pointer seems valid.

Until another function builds up the stack and overwrites it. This is why this can work for a while - and then suddenly cease to function after one particularly deeply nested set of functions, or a function with really huge sized or many local objects, reaches that stack-memory again.

It even can happen that you reach the same program part again, and overwrite your old local function variable with the new function variable. All this is very dangerous and should be heavily discouraged. Do not use pointers to local objects!

How to solve "java.io.IOException: error=12, Cannot allocate memory" calling Runtime#exec()?

overcommit_memory

Controls overcommit of system memory, possibly allowing processes to allocate (but not use) more memory than is actually available.

0 - Heuristic overcommit handling. Obvious overcommits of address space are refused. Used for a typical system. It ensures a seriously wild allocation fails while allowing overcommit to reduce swap usage. root is allowed to allocate slighly more memory in this mode. This is the default.

1 - Always overcommit. Appropriate for some scientific applications.

2 - Don't overcommit. The total address space commit for the system is not permitted to exceed swap plus a configurable percentage (default is 50) of physical RAM. Depending on the percentage you use, in most situations this means a process will not be killed while attempting to use already-allocated memory but will receive errors on memory allocation as appropriate.

How do I rename the android package name?

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

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

  2. Change package name in manifest (manually)

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

How do I get only directories using Get-ChildItem?

The accepted answer mentions

Get-ChildItem -Recurse | ?{ $_.PSIsContainer } | Select-Object FullName

to get a "raw string". But in fact objects of type Selected.System.IO.DirectoryInfo will be returned. For raw strings the following can be used:

Get-ChildItem -Recurse | ?{ $_.PSIsContainer } | % { $_.FullName }

The difference matters if the value is concatenated to a string:

  • with Select-Object suprisingly foo\@{FullName=bar}
  • with the ForEach-operator the expected: foo\bar

how to configure hibernate config file for sql server

The connection URL should look like this for SQL Server:

jdbc:sqlserver://serverName[\instanceName][:port][;databaseName=your_db_name]

Examples:

jdbc:sqlserver://localhost
jdbc:sqlserver://127.0.0.1\INGESQL:1433;databaseName=datatest
...

Soft hyphen in HTML (<wbr> vs. &shy;)

It is very important to notice that, as of HTML5, <wbr> and &shy; are not supposed to do the same thing!

Soft hyphens

&shy; is a soft hyphen, i.e., U+00AD: SOFT HYPHEN. For example,

innehålls&shy;förteckning

might be rendered as

innehållsförteckning

or as

innehålls-
förteckning

As of today, soft hyphens work in Firefox, Chrome, and Internet Explorer.

The wbr element

The wbr element is a word-break opportunity, which will not display a hyphen if a line break occurs. For example,

ABCDEFG<wbr/>abcdefg

might be rendered as

ABCDEFGabcdefg

or as

ABCDEFG
abcdefg

As of today, this element works in Firefox and Chrome.

How do I set an un-selectable default description in a select (drop-down) menu in HTML?

Although this question has an accepted answer but I think this is a much cleaner way to achieve the desired output

<select required>
<option value="">Select</option>
<option>English</option>
<option>Spanish</option>
</select>

The required attribute in makes it mandatory to select an option from the list.

value="" inside the option tag combined with the required attribute in select tag makes selection of 'Select' option not permissible, thus achieving the required output

Exec : display stdout "live"

There are already several answers however none of them mention the best (and easiest) way to do this, which is using spawn and the { stdio: 'inherit' } option. It seems to produce the most accurate output, for example when displaying the progress information from a git clone.

Simply do this:

var spawn = require('child_process').spawn;

spawn('coffee', ['-cw', 'my_file.coffee'], { stdio: 'inherit' });

Credit to @MorganTouvereyQuilling for pointing this out in this comment.

Display last git commit comment

I did this

git reflog -1 | sed 's/^.*: //'

Manually Set Value for FormBuilder Control

I know the answer is already given but I want give a bit brief answer how to update value of a form so that other new comers can get a clear idea.

your form structure is so perfect to use it as an example. so, throughout my answer I will denote it as the form.

this.form = this.fb.group({
    'name': ['', Validators.required],
    'dept': ['', Validators.required],
    'description': ['', Validators.required]
  });

so our form is a FormGroup type of object that has three FormControl.

There are two ways to update the model value:

  • Use the setValue() method to set a new value for an individual control. The setValue() method strictly adheres to the structure of the form group and replaces the entire value for the control.

  • Use the patchValue() method to replace any properties defined in the object that have changed in the form model.

The strict checks of the setValue() method help catch nesting errors in complex forms, while patchValue() fails silently on those errors.

From Angular official documentation here

so, When updating the value for a form group instance that contains multiple controls, but you may only want to update parts of the model. patchValue() is the one you are looking for.

lets see example. When you use patchValue()

this.form.patchValue({
    dept: 1 
});
//here we are just updating only dept field and it will work.

but when you use setValue() you need to update the full model as it strictly adheres the structure of the form group. so, if we write

this.form.setValue({
    dept: 1 
});
// it will throw error.

We must pass all the properties of the form group model. like this

this.form.setValue({
      name: 'Mr. Bean'
      dept: 1,
      description: 'spome description'
  });

but I don't use this style frequently. I prefer using the following approach that helps to keep my code cleaner and more understandable.

What I do is, I declare all the controls as a seperate variable and use setValue() to update that specific control.

for the above form, I will do something like this.

get companyIdentifier(): FormControl {
    return this.form.get('name') as FormControl;
}

get dept(): FormControl {
    return this.form.get('dept') as FormControl;
}

get description(): FormControl {
    return this.form.get('description') as FormControl;
}

when you need to update the form control just use that property to update it. In the example the questioner tried to update the dept form control when user select an item from the drop down list.

deptSelected(selected: { id: string; text: string }) {
  console.log(selected) // Shows proper selection!

  // instead of using this.form.controls['dept'].setValue(selected.id), I prefer the following.

  this.dept.setValue(selected.id); // this.dept is the property that returns the 'dept' FormControl of the form.
}

I suggest to have a look FormGroup API to get know how of all the properties and methods of FormGroup.

Additional: to know about getter see here

Validation failed for one or more entities. See 'EntityValidationErrors' property for more details

I had to write this in the Immediate window :3

(((exception as System.Data.Entity.Validation.DbEntityValidationException).EntityValidationErrors as System.Collections.Generic.List<System.Data.Entity.Validation.DbEntityValidationResult>)[0].ValidationErrors as System.Collections.Generic.List<System.Data.Entity.Validation.DbValidationError>)[0]

in order to get deep into the exact error !

Using ListView : How to add a header view?

I found out that inflating the header view as:

inflater.inflate(R.layout.listheader, container, false);

being container the Fragment's ViewGroup, inflates the headerview with a LayoutParam that extends from FragmentLayout but ListView expect it to be a AbsListView.LayoutParams instead.

So, my problem was solved solved by inflating the header view passing the list as container:

ListView list = fragmentview.findViewById(R.id.listview);
View headerView = inflater.inflate(R.layout.listheader, list, false);

then

list.addHeaderView(headerView, null, false);

Kinda late answer but I hope this can help someone

ImportError: No module named 'django.core.urlresolvers'

If your builds on TravisCI are failing for this particular reason, you can resolve the issue by updating the Django Extensions in your requirements.txt

pip install --upgrade django-extensions

This will update the extensions to use Django 2+ modules.

iPhone 6 and 6 Plus Media Queries

Just so you know the iPhone 6 lies about it's min-width. It thinks it is 320 instead of 375 it is suppose to be.

@media only screen and (max-device-width: 667px) 
and (-webkit-device-pixel-ratio: 2) {

}

This was the only thing I could get to work to target the iPhone 6. The 6+ works fine the using this method:

@media screen and (min-device-width : 414px) 
and (max-device-height : 736px) and (max-resolution: 401dpi)
{

}

TypeError: unsupported operand type(s) for /: 'str' and 'str'

The first thing you should do is learn to read error messages. What does it tell you -- that you can't use two strings with the divide operator.

So, ask yourself why they are strings and how do you make them not-strings. They are strings because all input is done via strings. And the way to make then not-strings is to convert them.

One way to convert a string to an integer is to use the int function. For example:

percent = (int(pyc) / int(tpy)) * 100

ng-change get new value and original value

You can use something like ng-change=someMethod({{user.id}}). By keeping your value in side {{expression}} it will evaluate expression in-line and gives you current value(value before ng-change method is called).

<select ng-model="selectedValue" ng-change="change(selectedValue, '{{selectedValue}}')">

Newtonsoft JSON Deserialize

You can implement a class that holds the fields you have in your JSON

class MyData
{
    public string t;
    public bool a;
    public object[] data;
    public string[][] type;
}

and then use the generic version of DeserializeObject:

MyData tmp = JsonConvert.DeserializeObject<MyData>(json);
foreach (string typeStr in tmp.type[0])
{
    // Do something with typeStr
}

Documentation: Serializing and Deserializing JSON

How to change default text file encoding in Eclipse?

What worked for me in Eclipse Mars was to go to Window > Preferences > Web > HTML Files, and in the right panel in Encoding select ISO 10646/Unicode(UTF-8), Apply and OK, then and only then my .html files were created with .

How do I push a local Git branch to master branch in the remote?

$ git push origin develop:master

or, more generally

$ git push <remote> <local branch name>:<remote branch to push into>

Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?

This is a simple solution for merging two dictionaries where += can be applied to the values, it has to iterate over a dictionary only once

a = {'a':1, 'b':2, 'c':3}

dicts = [{'b':3, 'c':4, 'd':5},
         {'c':9, 'a':9, 'd':9}]

def merge_dicts(merged,mergedfrom):
    for k,v in mergedfrom.items():
        if k in merged:
            merged[k] += v
        else:
            merged[k] = v
    return merged

for dct in dicts:
    a = merge_dicts(a,dct)
print (a)
#{'c': 16, 'b': 5, 'd': 14, 'a': 10}

How to print in C

printf is a fair bit more complicated than that. You have to supply a format string, and then the variables to apply to the format string. If you just supply one variable, C will assume that is the format string and try to print out all the bytes it finds in it until it hits a terminating nul (0x0).

So if you just give it an integer, it will merrily march through memory at the location your integer is stored, dumping whatever garbage is there to the screen, until it happens to come across a byte containing 0.

For a Java programmer, I'd imagine this is a rather rude introduction to C's lack of type checking. Believe me, this is only the tip of the iceberg. This is why, while I applaud your desire to expand your horizons by learning C, I highly suggest you do whatever you can to avoid writing real programs in it.

(This goes for everyone else reading this too.)

Using Javamail to connect to Gmail smtp server ignores specified port and tries to use 25

For anyone looking for a full solution, I got this working with the following code based on maximdim's answer:

import javax.mail.*
import javax.mail.internet.*

private class SMTPAuthenticator extends Authenticator
{
    public PasswordAuthentication getPasswordAuthentication()
    {
        return new PasswordAuthentication('[email protected]', 'test1234');
    }
}

def  d_email = "[email protected]",
        d_uname = "email",
        d_password = "password",
        d_host = "smtp.gmail.com",
        d_port  = "465", //465,587
        m_to = "[email protected]",
        m_subject = "Testing",
        m_text = "Hey, this is the testing email."

def props = new Properties()
props.put("mail.smtp.user", d_email)
props.put("mail.smtp.host", d_host)
props.put("mail.smtp.port", d_port)
props.put("mail.smtp.starttls.enable","true")
props.put("mail.smtp.debug", "true");
props.put("mail.smtp.auth", "true")
props.put("mail.smtp.socketFactory.port", d_port)
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory")
props.put("mail.smtp.socketFactory.fallback", "false")

def auth = new SMTPAuthenticator()
def session = Session.getInstance(props, auth)
session.setDebug(true);

def msg = new MimeMessage(session)
msg.setText(m_text)
msg.setSubject(m_subject)
msg.setFrom(new InternetAddress(d_email))
msg.addRecipient(Message.RecipientType.TO, new InternetAddress(m_to))

Transport transport = session.getTransport("smtps");
transport.connect(d_host, 465, d_uname, d_password);
transport.sendMessage(msg, msg.getAllRecipients());
transport.close();

Bootstrap: Position of dropdown menu relative to navbar item

Boostrap has a class for that called navbar-right. So your code will look as follows:

<ul class="nav navbar-right">
    <li class="dropdown">
      <a class="dropdown-toggle" href="#" data-toggle="dropdown">Link</a>
      <ul class="dropdown-menu">
         <li>...</li>
      </ul>
    </li>
</ul>

nvarchar(max) vs NText

You should apparently use nvarchar(max):

MSDN

fast way to copy formatting in excel

Remember that when you write:

MyArray = Range("A1:A5000")

you are really writing

MyArray = Range("A1:A5000").Value

You can also use names:

MyArray = Names("MyWSTable").RefersToRange.Value

But Value is not the only property of Range. I have used:

MyArray = Range("A1:A5000").NumberFormat

I doubt

MyArray = Range("A1:A5000").Font

would work but I would expect

MyArray = Range("A1:A5000").Font.Bold

to work.

I do not know what formats you want to copy so you will have to try.

However, I must add that when you copy and paste a large range, it is not as much slower than doing it via an array as we all thought.

Post Edit information

Having posted the above I tried by own advice. My experiments with copying Font.Color and Font.Bold to an array have failed.

Of the following statements, the second would fail with a type mismatch:

  ValueArray = .Range("A1:T5000").Value
  ColourArray = .Range("A1:T5000").Font.Color

ValueArray must be of type variant. I tried both variant and long for ColourArray without success.

I filled ColourArray with values and tried the following statement:

  .Range("A1:T5000").Font.Color = ColourArray

The entire range would be coloured according to the first element of ColourArray and then Excel looped consuming about 45% of the processor time until I terminated it with the Task Manager.

There is a time penalty associated with switching between worksheets but recent questions about macro duration have caused everyone to review our belief that working via arrays was substantially quicker.

I constructed an experiment that broadly reflects your requirement. I filled worksheet Time1 with 5000 rows of 20 cells which were selectively formatted as: bold, italic, underline, subscript, bordered, red, green, blue, brown, yellow and gray-80%.

With version 1, I copied every 7th cells from worksheet "Time1" to worksheet "Time2" using copy.

With version 2, I copied every 7th cells from worksheet "Time1" to worksheet "Time2" by copying the value and the colour via an array.

With version 3, I copied every 7th cells from worksheet "Time1" to worksheet "Time2" by copying the formula and the colour via an array.

Version 1 took an average of 12.43 seconds, version 2 took an average of 1.47 seconds while version 3 took an average of 1.83 seconds. Version 1 copied formulae and all formatting, version 2 copied values and colour while version 3 copied formulae and colour. With versions 1 and 2 you could add bold and italic, say, and still have some time in hand. However, I am not sure it would be worth the bother given that copying 21,300 values only takes 12 seconds.

** Code for Version 1**

I do not think this code includes anything that needs an explanation. Respond with a comment if I am wrong and I will fix.

Sub SelectionCopyAndPaste()

  Dim ColDestCrnt As Integer
  Dim ColSrcCrnt As Integer
  Dim NumSelect As Long
  Dim RowDestCrnt As Integer
  Dim RowSrcCrnt As Integer
  Dim StartTime As Single

  Application.ScreenUpdating = False
  Application.Calculation = xlCalculationManual
  NumSelect = 1
  ColDestCrnt = 1
  RowDestCrnt = 1
  With Sheets("Time2")
    .Range("A1:T715").EntireRow.Delete
  End With
  StartTime = Timer
  Do While True
    ColSrcCrnt = (NumSelect Mod 20) + 1
    RowSrcCrnt = (NumSelect - ColSrcCrnt) / 20 + 1
    If RowSrcCrnt > 5000 Then
      Exit Do
    End If
    Sheets("Time1").Cells(RowSrcCrnt, ColSrcCrnt).Copy _
                 Destination:=Sheets("Time2").Cells(RowDestCrnt, ColDestCrnt)
    If ColDestCrnt = 20 Then
      ColDestCrnt = 1
      RowDestCrnt = RowDestCrnt + 1
    Else
     ColDestCrnt = ColDestCrnt + 1
    End If
    NumSelect = NumSelect + 7
  Loop
  Debug.Print Timer - StartTime
  ' Average 12.43 secs
  Application.Calculation = xlCalculationAutomatic

End Sub

** Code for Versions 2 and 3**

The User type definition must be placed before any subroutine in the module. The code works through the source worksheet copying values or formulae and colours to the next element of the array. Once selection has been completed, it copies the collected information to the destination worksheet. This avoids switching between worksheets more than is essential.

Type ValueDtl
  Value As String
  Colour As Long
End Type

Sub SelectionViaArray()

  Dim ColDestCrnt As Integer
  Dim ColSrcCrnt As Integer
  Dim InxVLCrnt As Integer
  Dim InxVLCrntMax As Integer
  Dim NumSelect As Long
  Dim RowDestCrnt As Integer
  Dim RowSrcCrnt As Integer
  Dim StartTime As Single
  Dim ValueList() As ValueDtl

  Application.ScreenUpdating = False
  Application.Calculation = xlCalculationManual

  ' I have sized the array to more than I expect to require because ReDim
  ' Preserve is expensive.  However, I will resize if I fill the array.
  ' For my experiment I know exactly how many elements I need but that
  ' might not be true for you.
  ReDim ValueList(1 To 25000)

  NumSelect = 1
  ColDestCrnt = 1
  RowDestCrnt = 1
  InxVLCrntMax = 0      ' Last used element in ValueList.
  With Sheets("Time2")
    .Range("A1:T715").EntireRow.Delete
  End With
  StartTime = Timer
  With Sheets("Time1")
    Do While True
      ColSrcCrnt = (NumSelect Mod 20) + 1
      RowSrcCrnt = (NumSelect - ColSrcCrnt) / 20 + 1
      If RowSrcCrnt > 5000 Then
        Exit Do
      End If
      InxVLCrntMax = InxVLCrntMax + 1
      If InxVLCrntMax > UBound(ValueList) Then
        ' Resize array if it has been filled 
        ReDim Preserve ValueList(1 To UBound(ValueList) + 1000)
      End If
      With .Cells(RowSrcCrnt, ColSrcCrnt)
        ValueList(InxVLCrntMax).Value = .Value              ' Version 2
        ValueList(InxVLCrntMax).Value = .Formula            ' Version 3
        ValueList(InxVLCrntMax).Colour = .Font.Color
      End With
      NumSelect = NumSelect + 7
    Loop
  End With
  With Sheets("Time2")
    For InxVLCrnt = 1 To InxVLCrntMax
      With .Cells(RowDestCrnt, ColDestCrnt)
        .Value = ValueList(InxVLCrnt).Value                 ' Version 2
        .Formula = ValueList(InxVLCrnt).Value               ' Version 3
        .Font.Color = ValueList(InxVLCrnt).Colour
      End With
      If ColDestCrnt = 20 Then
        ColDestCrnt = 1
        RowDestCrnt = RowDestCrnt + 1
      Else
       ColDestCrnt = ColDestCrnt + 1
      End If
    Next
  End With
  Debug.Print Timer - StartTime
  ' Version 2 average 1.47 secs
  ' Version 3 average 1.83 secs
  Application.Calculation = xlCalculationAutomatic

End Sub

Position absolute and overflow hidden

An absolutely positioned element is actually positioned regarding a relative parent, or the nearest found relative parent. So the element with overflow: hidden should be between relative and absolute positioned elements:

<div class="relative-parent">
  <div class="hiding-parent">
    <div class="child"></div>
  </div>
</div>

.relative-parent {
  position:relative;
}
.hiding-parent {
  overflow:hidden;
}
.child {
  position:absolute; 
}

CentOS: Copy directory to another directory

To copy all files, including hidden files use:

cp -r /home/server/folder/test/. /home/server/

What is the best way to get the count/length/size of an iterator?

There is no more efficient way, if all you have is the iterator. And if the iterator can only be used once, then getting the count before you get the iterator's contents is ... problematic.

The solution is either to change your application so that it doesn't need the count, or to obtain the count by some other means. (For example, pass a Collection rather than Iterator ...)

What exactly is the difference between Web API and REST API in MVC?

I have been there, like so many of us. There are so many confusing words like Web API, REST, RESTful, HTTP, SOAP, WCF, Web Services... and many more around this topic. But I am going to give brief explanation of only those which you have asked.

REST

It is neither an API nor a framework. It is just an architectural concept. You can find more details here.

RESTful

I have not come across any formal definition of RESTful anywhere. I believe it is just another buzzword for APIs to say if they comply with REST specifications.

EDIT: There is another trending open source initiative OpenAPI Specification (OAS) (formerly known as Swagger) to standardise REST APIs.

Web API

It in an open source framework for writing HTTP APIs. These APIs can be RESTful or not. Most HTTP APIs we write are not RESTful. This framework implements HTTP protocol specification and hence you hear terms like URIs, request/response headers, caching, versioning, various content types(formats).

Note: I have not used the term Web Services deliberately because it is a confusing term to use. Some people use this as a generic concept, I preferred to call them HTTP APIs. There is an actual framework named 'Web Services' by Microsoft like Web API. However it implements another protocol called SOAP.

Trees in Twitter Bootstrap

If someone wants expandable/collapsible version of the treeview from Vitaliy Bychik's answer, you can save some time :)

http://jsfiddle.net/mehmetatas/fXzHS/2/

$(function () {
    $('.tree li').hide();
    $('.tree li:first').show();
    $('.tree li').on('click', function (e) {
        var children = $(this).find('> ul > li');
        if (children.is(":visible")) children.hide('fast');
        else children.show('fast');
        e.stopPropagation();
    });
});

Finding out current index in EACH loop (Ruby)

X.each_with_index do |item, index|
  puts "current_index: #{index}"
end

Is there a destructor for Java?

The closest equivalent to a destructor in Java is the finalize() method. The big difference to a traditional destructor is that you can't be sure when it'll be called, since that's the responsibility of the garbage collector. I'd strongly recommend carefully reading up on this before using it, since your typical RAIA patterns for file handles and so on won't work reliably with finalize().

Capitalize the first letter of string in AngularJs

if (value){
  value = (value.length > 1) ? value[0].toUpperCase() + value.substr(1).toLowerCase() : value.toUpperCase();
}

Regex select all text between tags

Try this....

(?<=\<any_tag\>)(\s*.*\s*)(?=\<\/any_tag\>)

comparing two strings in SQL Server

There is no direct string compare function in SQL Server

CASE
  WHEN str1 = str2 THEN 0
  WHEN str1 < str2 THEN -1
  WHEN str1 > str2 THEN 1
  ELSE NULL --one of the strings is NULL so won't compare (added on edit)
END

Notes

  • you can wraps this via a UDF using CREATE FUNCTION etc
  • you may need NULL handling (in my code above, any NULL will report 1)
  • str1 and str2 will be column names or @variables

How to make a section of an image a clickable link

The easiest way is to make the "button image" as a separate image. Then place it over the main image (using "style="position: absolute;". Assign the URL link to "button image". and smile :)

Create component to specific module with Angular-CLI

if you want to create along with your module try this

  ng generate m module_name --routing &&  ng generate c component_name

Avoid duplicates in INSERT INTO SELECT query in SQL Server

A simple DELETE before the INSERT would suffice:

DELETE FROM Table2 WHERE Id = (SELECT Id FROM Table1)
INSERT INTO Table2 (Id, name) SELECT Id, name FROM Table1

Switching Table1 for Table2 depending on which table's Id and name pairing you want to preserve.

How to set limits for axes in ggplot2 R plots?

Basically you have two options

scale_x_continuous(limits = c(-5000, 5000))

or

coord_cartesian(xlim = c(-5000, 5000)) 

Where the first removes all data points outside the given range and the second only adjusts the visible area. In most cases you would not see the difference, but if you fit anything to the data it would probably change the fitted values.

You can also use the shorthand function xlim (or ylim), which like the first option removes data points outside of the given range:

+ xlim(-5000, 5000)

For more information check the description of coord_cartesian.

The RStudio cheatsheet for ggplot2 makes this quite clear visually. Here is a small section of that cheatsheet:

enter image description here

Distributed under CC BY.

How to change MySQL data directory?

I wanted to keep a database on my machine, but also have a data on my external hard drive, and switch between using the two.

If you are on a Mac, and installed MySQL using Homebrew, this should work for you. Otherwise, you will just need to substitute the appropriate locations for the MySQL datadir on your machine.

#cd to my data dir location
cd /usr/local/var/

#copy contents of local data directory to the new location
cp -r mysql/ /Volumes/myhd/mydatadir/

#temporarily move the old datadir
mv mysql mysql.local

#symlink to the new location
ln -s /Volumes/myhd/mydatadir mysql

Then to when you want to switch back simply do:

mv mysql mysql.remote

mv mysql.local mysql

and you are using your local database again. Hope that helps.

What's the most efficient way to erase duplicates and sort a vector?

I agree with R. Pate and Todd Gardner; a std::set might be a good idea here. Even if you're stuck using vectors, if you have enough duplicates, you might be better off creating a set to do the dirty work.

Let's compare three approaches:

Just using vector, sort + unique

sort( vec.begin(), vec.end() );
vec.erase( unique( vec.begin(), vec.end() ), vec.end() );

Convert to set (manually)

set<int> s;
unsigned size = vec.size();
for( unsigned i = 0; i < size; ++i ) s.insert( vec[i] );
vec.assign( s.begin(), s.end() );

Convert to set (using a constructor)

set<int> s( vec.begin(), vec.end() );
vec.assign( s.begin(), s.end() );

Here's how these perform as the number of duplicates changes:

comparison of vector and set approaches

Summary: when the number of duplicates is large enough, it's actually faster to convert to a set and then dump the data back into a vector.

And for some reason, doing the set conversion manually seems to be faster than using the set constructor -- at least on the toy random data that I used.

Instantiating a generic type

You cannot do new T() due to type erasure. The default constructor can only be

public Navigation() {     this("", "", null); } 

​ You can create other constructors to provide default values for trigger and description. You need an concrete object of T.

What is the difference between "long", "long long", "long int", and "long long int" in C++?

long and long int are identical. So are long long and long long int. In both cases, the int is optional.

As to the difference between the two sets, the C++ standard mandates minimum ranges for each, and that long long is at least as wide as long.

The controlling parts of the standard (C++11, but this has been around for a long time) are, for one, 3.9.1 Fundamental types, section 2 (a later section gives similar rules for the unsigned integral types):

There are five standard signed integer types : signed char, short int, int, long int, and long long int. In this list, each type provides at least as much storage as those preceding it in the list.

There's also a table 9 in 7.1.6.2 Simple type specifiers, which shows the "mappings" of the specifiers to actual types (showing that the int is optional), a section of which is shown below:

Specifier(s)         Type
-------------    -------------
long long int    long long int
long long        long long int
long int         long int
long             long int

Note the distinction there between the specifier and the type. The specifier is how you tell the compiler what the type is but you can use different specifiers to end up at the same type.

Hence long on its own is neither a type nor a modifier as your question posits, it's simply a specifier for the long int type. Ditto for long long being a specifier for the long long int type.

Although the C++ standard itself doesn't specify the minimum ranges of integral types, it does cite C99, in 1.2 Normative references, as applying. Hence the minimal ranges as set out in C99 5.2.4.2.1 Sizes of integer types <limits.h> are applicable.


In terms of long double, that's actually a floating point value rather than an integer. Similarly to the integral types, it's required to have at least as much precision as a double and to provide a superset of values over that type (meaning at least those values, not necessarily more values).

How I can filter a Datatable?

Sometimes you actually want to return a DataTable than a DataView. So a DataView was not good in my case and I guess few others would want that too. Here is what I used to do

myDataTable.select("myquery").CopyToDataTable()

This will filter myDataTable which is a DataTable and return a new DataTable

Hope someone will find that is useful

How to detect the physical connected state of a network cable/connector?

Somehow if you want to check if the ethernet cable plugged in linux after the commend:" ifconfig eth0 down". I find a solution: use the ethtool tool.

#ethtool -t eth0
The test result is PASS
The test extra info:
Register test  (offline)         0
Eeprom test    (offline)         0
Interrupt test (offline)         0
Loopback test  (offline)         0
Link test   (on/offline)         0

if cable is connected,link test is 0,otherwise is 1.

What are the ways to sum matrix elements in MATLAB?

Avoid for loops whenever possible.

sum(A(:))

is great however if you have some logical indexing going on you can't use the (:) but you can write

% Sum all elements under 45 in the matrix
sum ( sum ( A *. ( A < 45 ) )

Since sum sums the columns and sums the row vector that was created by the first sum. Note that this only works if the matrix is 2-dim.

Android ClassNotFoundException: Didn't find class on path

I found this error in Android Studio when i tried do debug in a device with API 23, so i checked the Android Studio and i noticed that i didnt had instaled this API 23 version. After install, i solved the problem.

Checkout one file from Subversion

If you just want to export the file, and you won't need to update it later, you can do it without having to use SVN commands.

Using TortoiseSVN Repository Browser, select the file, right click, and then select "Copy URL to clipboard". Paste that URL to your browser, and after login you should be prompted with the file download.

This way you can also select desired revision and download an older version of the file.

Note that this is valid if your SVN server has a web interface.

How to take backup of a single table in a MySQL database?

Dump and restore a single table from .sql

Dump

mysqldump db_name table_name > table_name.sql

Dumping from a remote database

mysqldump -u <db_username> -h <db_host> -p db_name table_name > table_name.sql

For further reference:

http://www.abbeyworkshop.com/howto/lamp/MySQL_Export_Backup/index.html

Restore

mysql -u <user_name> -p db_name
mysql> source <full_path>/table_name.sql

or in one line

mysql -u username -p db_name < /path/to/table_name.sql


Dump and restore a single table from a compressed (.sql.gz) format

Credit: John McGrath

Dump

mysqldump db_name table_name | gzip > table_name.sql.gz

Restore

gunzip < table_name.sql.gz | mysql -u username -p db_name

SQL ORDER BY date problem

this works for me:

SELECT datefield FROM myTable ORDER BY CONVERT(DATE, datefield) ASC

JavaScript: Create and save file

Choosing the location to save the file before creating it is not possible. But it is possible, at least in Chrome, to generate files using just JavaScript. Here is an old example of mine of creating a CSV file. The user will be prompted to download it. This, unfortunately, does not work well in other browsers, especially IE.

<!DOCTYPE html>
<html>
<head>
    <title>JS CSV</title>
</head>
<body>
    <button id="b">export to CSV</button>
    <script type="text/javascript">
        function exportToCsv() {
            var myCsv = "Col1,Col2,Col3\nval1,val2,val3";

            window.open('data:text/csv;charset=utf-8,' + escape(myCsv));
        }

        var button = document.getElementById('b');
        button.addEventListener('click', exportToCsv);
    </script>
</body>
</html>

Replace first occurrence of pattern in a string

I think you can use the overload of Regex.Replace to specify the maximum number of times to replace...

var regex = new Regex(Regex.Escape("o"));
var newText = regex.Replace("Hello World", "Foo", 1);

Alter Table Add Column Syntax

This is how Adding new column to Table

ALTER TABLE [tableName]
ADD ColumnName Datatype

E.g

ALTER TABLE [Emp]
ADD Sr_No Int

And If you want to make it auto incremented

ALTER TABLE [Emp]
ADD Sr_No Int IDENTITY(1,1) NOT NULL