Programs & Examples On #Template method pattern

The Template Method pattern is a design pattern that defines the program skeleton of an algorithm in a method, called a template method, which defers some steps to subclasses. It is one of the Gang of Four's behavioral design patterns.

Insert data into a view (SQL Server)

You just need to specify which columns you're inserting directly into:

INSERT INTO [dbo].[rLicenses] ([Name]) VALUES ('test')

Views can be picky like that.

Javascript onclick hide div

Simple & Best way:

onclick="parentNode.remove()"

Deletes the complete parent from html

Bootstrap 3 - Set Container Width to 940px Maximum for Desktops?

The best option is to use the original LESS version of bootstrap (get it from github).

Open variables.less and look for // Media queries breakpoints

Find this code and change the breakpoint value:

// Large screen / wide desktop
@screen-lg:                  1200px; // change this
@screen-lg-desktop:          @screen-lg;

Change it to 9999px for example, and this will prevent the breakpoint to be reached, so your site will always load the previous media query which has 940px container

Config Error: This configuration section cannot be used at this path

You need to unlock handlers. This can be done using following cmd command:

%windir%\system32\inetsrv\appcmd.exe unlock config -section:system.webServer/handlers

Maybe another info for people that are getting this error on IIS 8, in my case was on Microsoft Server 2012 platform. I had spend couple of hours battling with other errors that bubbled up after executing appcmd. In the end I was able to fix it by removing Web Server Role and installing it again.

sorting and paging with gridview asp.net

I found a much easier way, which allows you to still use the built in sorting/paging of the standard gridview...

create 2 labels. set them to be visible = false. I called mine lblSort1 and lblSortDirection1

then code 2 simple events... the page sorting, which writes to the text of the invisible labels, and the page index changing, which uses them...

Private Sub gridview_Sorting(sender As Object, e As GridViewSortEventArgs) Handles gridview.Sorting
lblSort1.Text = e.SortExpression
lblSortDirection1.Text = e.SortDirection
End Sub

Private Sub gridview_PageIndexChanging(sender As Object, e As GridViewPageEventArgs) Handles gridview.PageIndexChanging
    gridview.Sort(lblSort1.Text, CInt(lblSortDirection1.Text))
End Sub

this is a little sloppier than using global variables, but I've found with asp especially that global vars are, well, unreliable...

Is there are way to make a child DIV's width wider than the parent DIV using CSS?

you can try position: absolute. and give width and height , top: 'y axis from the top' and left: 'x-axis'

Fitting a histogram with python

Here you have an example working on py2.6 and py3.2:

from scipy.stats import norm
import matplotlib.mlab as mlab
import matplotlib.pyplot as plt

# read data from a text file. One number per line
arch = "test/Log(2)_ACRatio.txt"
datos = []
for item in open(arch,'r'):
    item = item.strip()
    if item != '':
        try:
            datos.append(float(item))
        except ValueError:
            pass

# best fit of data
(mu, sigma) = norm.fit(datos)

# the histogram of the data
n, bins, patches = plt.hist(datos, 60, normed=1, facecolor='green', alpha=0.75)

# add a 'best fit' line
y = mlab.normpdf( bins, mu, sigma)
l = plt.plot(bins, y, 'r--', linewidth=2)

#plot
plt.xlabel('Smarts')
plt.ylabel('Probability')
plt.title(r'$\mathrm{Histogram\ of\ IQ:}\ \mu=%.3f,\ \sigma=%.3f$' %(mu, sigma))
plt.grid(True)

plt.show()

enter image description here

403 Forbidden error when making an ajax Post request in Django framework

this works for me

template.html

  $.ajax({
    url: "{% url 'XXXXXX' %}",
    type: 'POST',
    data: {modifica: jsonText, "csrfmiddlewaretoken" : "{{csrf_token}}"},
    traditional: true,
    dataType: 'html',
    success: function(result){
       window.location.href = "{% url 'XXX' %}";
        }
});

view.py

def aggiornaAttivitaAssegnate(request):
    if request.is_ajax():
        richiesta = json.loads(request.POST.get('modifica'))

How many files can I put in a directory?

If the time involved in implementing a directory partitioning scheme is minimal, I am in favor of it. The first time you have to debug a problem that involves manipulating a 10000-file directory via the console you will understand.

As an example, F-Spot stores photo files as YYYY\MM\DD\filename.ext, which means the largest directory I have had to deal with while manually manipulating my ~20000-photo collection is about 800 files. This also makes the files more easily browsable from a third party application. Never assume that your software is the only thing that will be accessing your software's files.

How to create a service running a .exe file on Windows 2012 Server?

You can just do that too, it seems to work well too. sc create "Servicename" binPath= "Path\To\your\App.exe" DisplayName= "My Custom Service"

You can open the registry and add a string named Description in your service's registry key to add a little more descriptive information about it. It will be shown in services.msc.

Share Text on Facebook from Android App via ACTION_SEND

It appears that the Facebook app handles this intent incorrectly. The most reliable way seems to be to use the Facebook API for Android.

The SDK is at this link: http://github.com/facebook/facebook-android-sdk

Under 'usage', there is this:

Display a Facebook dialog.

The SDK supports several WebView html dialogs for user interactions, such as creating a wall post. This is intended to provided quick Facebook functionality without having to implement a native Android UI and pass data to facebook directly though the APIs.

This seems like the best way to do it -- display a dialog that will post to the wall. The only issue is that they may have to log in first

How to create a directive with a dynamic template in AngularJS?

i've used the $templateCache to accomplish something similar. i put several ng-templates in a single html file, which i reference using the directive's templateUrl. that ensures the html is available to the template cache. then i can simply select by id to get the ng-template i want.

template.html:

<script type="text/ng-template" id=“foo”>
foo
</script>

<script type="text/ng-template" id=“bar”>
bar
</script>

directive:

myapp.directive(‘foobardirective’, ['$compile', '$templateCache', function ($compile, $templateCache) {

    var getTemplate = function(data) {
        // use data to determine which template to use
        var templateid = 'foo';
        var template = $templateCache.get(templateid);
        return template;
    }

    return {
        templateUrl: 'views/partials/template.html',
        scope: {data: '='},
        restrict: 'E',
        link: function(scope, element) {
            var template = getTemplate(scope.data);

            element.html(template);
            $compile(element.contents())(scope);
        }
    };
}]);

Use Font Awesome Icon in Placeholder

There is some slight delay and jank as the font changes in the answer provided by Jason. Using the "change" event instead of "keyup" resolves this issue.

$('#iconified').on('change', function() {
    var input = $(this);
    if(input.val().length === 0) {
        input.addClass('empty');
    } else {
        input.removeClass('empty');
    }
});

What is the purpose of a question mark after a type (for example: int? myVariable)?

Nullable Types

Nullable types are instances of the System.Nullable struct. A nullable type can represent the normal range of values for its underlying value type, plus an additional null value. For example, a [Nullable<Int32>], pronounced "Nullable of Int32," can be assigned any value from -2147483648 to 2147483647, or it can be assigned the null value. A [Nullable<bool>] can be assigned the values true or false, or null. The ability to assign null to numeric and Boolean types is particularly useful when dealing with databases and other data types containing elements that may not be assigned a value. For example, a Boolean field in a database can store the values true or false, or it may be undefined.

Set focus and cursor to end of text input field / string w. Jquery

You can do this using Input.setSelectionRange, part of the Range API for interacting with text selections and the text cursor:

var searchInput = $('#Search');

// Multiply by 2 to ensure the cursor always ends up at the end;
// Opera sometimes sees a carriage return as 2 characters.
var strLength = searchInput.val().length * 2;

searchInput.focus();
searchInput[0].setSelectionRange(strLength, strLength);

Demo: Fiddle

Failed loading english.pickle with nltk.data.load

i came across this problem when i was trying to do pos tagging in nltk. the way i got it correct is by making a new directory along with corpora directory named "taggers" and copying max_pos_tagger in directory taggers.
hope it works for you too. best of luck with it!!!.

In a Django form, how do I make a field readonly (or disabled) so that it cannot be edited?

I made a MixIn class which you may inherit to be able to add a read_only iterable field which will disable and secure fields on the non-first edit:

(Based on Daniel's and Muhuk's answers)

from django import forms
from django.db.models.manager import Manager

# I used this instead of lambda expression after scope problems
def _get_cleaner(form, field):
    def clean_field():
         value = getattr(form.instance, field, None)
         if issubclass(type(value), Manager):
             value = value.all()
         return value
    return clean_field

class ROFormMixin(forms.BaseForm):
    def __init__(self, *args, **kwargs):
        super(ROFormMixin, self).__init__(*args, **kwargs)
        if hasattr(self, "read_only"):
            if self.instance and self.instance.pk:
                for field in self.read_only:
                    self.fields[field].widget.attrs['readonly'] = "readonly"
                    setattr(self, "clean_" + field, _get_cleaner(self, field))

# Basic usage
class TestForm(AModelForm, ROFormMixin):
    read_only = ('sku', 'an_other_field')

Accessing AppDelegate from framework?

If you're creating a framework the whole idea is to make it portable. Tying a framework to the app delegate defeats the purpose of building a framework. What is it you need the app delegate for?

Setting std=c99 flag in GCC

How about alias gcc99= gcc -std=c99?

On delete cascade with doctrine2

There are two kinds of cascades in Doctrine:

1) ORM level - uses cascade={"remove"} in the association - this is a calculation that is done in the UnitOfWork and does not affect the database structure. When you remove an object, the UnitOfWork will iterate over all objects in the association and remove them.

2) Database level - uses onDelete="CASCADE" on the association's joinColumn - this will add On Delete Cascade to the foreign key column in the database:

@ORM\JoinColumn(name="father_id", referencedColumnName="id", onDelete="CASCADE")

I also want to point out that the way you have your cascade={"remove"} right now, if you delete a Child object, this cascade will remove the Parent object. Clearly not what you want.

Java Array Sort descending?

I don't know what your use case was, however in addition to other answers here another (lazy) option is to still sort in ascending order as you indicate but then iterate in reverse order instead.

anaconda - graphviz - can't import after installation

I tried this way and worked for me.

conda install -c anaconda graphviz
pip install graphviz

Call static methods from regular ES6 class methods

If you are planning on doing any kind of inheritance, then I would recommend this.constructor. This simple example should illustrate why:

class ConstructorSuper {
  constructor(n){
    this.n = n;
  }

  static print(n){
    console.log(this.name, n);
  }

  callPrint(){
    this.constructor.print(this.n);
  }
}

class ConstructorSub extends ConstructorSuper {
  constructor(n){
    this.n = n;
  }
}

let test1 = new ConstructorSuper("Hello ConstructorSuper!");
console.log(test1.callPrint());

let test2 = new ConstructorSub("Hello ConstructorSub!");
console.log(test2.callPrint());
  • test1.callPrint() will log ConstructorSuper Hello ConstructorSuper! to the console
  • test2.callPrint() will log ConstructorSub Hello ConstructorSub! to the console

The named class will not deal with inheritance nicely unless you explicitly redefine every function that makes a reference to the named Class. Here is an example:

class NamedSuper {
  constructor(n){
    this.n = n;
  }

  static print(n){
    console.log(NamedSuper.name, n);
  }

  callPrint(){
    NamedSuper.print(this.n);
  }
}

class NamedSub extends NamedSuper {
  constructor(n){
    this.n = n;
  }
}

let test3 = new NamedSuper("Hello NamedSuper!");
console.log(test3.callPrint());

let test4 = new NamedSub("Hello NamedSub!");
console.log(test4.callPrint());
  • test3.callPrint() will log NamedSuper Hello NamedSuper! to the console
  • test4.callPrint() will log NamedSuper Hello NamedSub! to the console

See all the above running in Babel REPL.

You can see from this that test4 still thinks it's in the super class; in this example it might not seem like a huge deal, but if you are trying to reference member functions that have been overridden or new member variables, you'll find yourself in trouble.

Change language of Visual Studio 2017 RC

I didn't find a complete answer here

Firstly

You should install your preferred language

  1. Open the Visual Studio Installer.
  2. In installed products click on plus Dropdown menu
  3. click edit
  4. then click on language packs
  5. choose you preferred language and finally click on install

Secondly

  1. Go to Tools -> Options

    2.Select International Settings in Environment

    3.click on Menu and select you preferred language

    4.Click on Ok

    5.restart visual studio

SQL query: Delete all records from the table except latest N?

You cannot delete the records that way, the main issue being that you cannot use a subquery to specify the value of a LIMIT clause.

This works (tested in MySQL 5.0.67):

DELETE FROM `table`
WHERE id NOT IN (
  SELECT id
  FROM (
    SELECT id
    FROM `table`
    ORDER BY id DESC
    LIMIT 42 -- keep this many records
  ) foo
);

The intermediate subquery is required. Without it we'd run into two errors:

  1. SQL Error (1093): You can't specify target table 'table' for update in FROM clause - MySQL doesn't allow you to refer to the table you are deleting from within a direct subquery.
  2. SQL Error (1235): This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery' - You can't use the LIMIT clause within a direct subquery of a NOT IN operator.

Fortunately, using an intermediate subquery allows us to bypass both of these limitations.


Nicole has pointed out this query can be optimised significantly for certain use cases (such as this one). I recommend reading that answer as well to see if it fits yours.

Simple 3x3 matrix inverse code (C++)

Don't try to do this yourself if you're serious about getting edge cases right. So while they many naive/simple methods are theoretically exact, they can have nasty numerical behavior for nearly singular matrices. In particular you can get cancelation/round-off errors that cause you to get arbitrarily bad results.

A "correct" way is Gaussian elimination with row and column pivoting so that you're always dividing by the largest remaining numerical value. (This is also stable for NxN matrices.). Note that row pivoting alone doesn't catch all the bad cases.

However IMO implementing this right and fast is not worth your time - use a well tested library and there are a heap of header only ones.

How to replace all spaces in a string

VERY EASY:

just use this to replace all white spaces with -:

myString.replace(/ /g,"-")

Populate data table from data reader

If you're trying to load a DataTable, then leverage the SqlDataAdapter instead:

DataTable dt = new DataTable();

using (SqlConnection c = new SqlConnection(cString))
using (SqlDataAdapter sda = new SqlDataAdapter(sql, c))
{
    sda.SelectCommand.CommandType = CommandType.StoredProcedure;
    sda.SelectCommand.Parameters.AddWithValue("@parm1", val1);
    ...

    sda.Fill(dt);
}

You don't even need to define the columns. Just create the DataTable and Fill it.

Here, cString is your connection string and sql is the stored procedure command.

I can't install python-ldap

sudo apt-get install build-essential python3-dev python2.7-dev libldap2-dev libsasl2-dev slapd ldap-utils python-tox lcov valgrind

How can I declare and define multiple variables in one line using C++?

template <typename ...A>
constexpr auto assign(A& ...a) noexcept
{
  return [&](auto&& ...v) noexcept(noexcept(
    ((a = std::forward<decltype(v)>(v)), ...)))
    {
      ((a = std::forward<decltype(v)>(v)), ...);
    };
}

int column, row, index;

assign(column, row, index)(0, 0, 0);

Excel formula to reference 'CELL TO THE LEFT'

Make a named formula "LeftCell"

For those looking for a non-volatile answer, you can accomplish this by using the INDEX function in a named formula.

  1. Select Cell A2

  2. Open Name Manager (Ctrl+F3)

  3. Click New

  4. Name it 'LeftCell' (or whatever you prefer)

  5. For Scope:, select Workbook

  6. In Refers to:, enter the formula:

    =INDEX(!A1:!A2, 1)

  7. Click OK and close Name Manager

This tells Excel to always look at the value immediately to the left of the current cell, and will change dynamically as different cells are selected. If the name is used alone it provides the cell's value, but in a range it uses the reference. Credit to this answer about cell references for the idea.

Android offline documentation and sample codes

If you install the SDK, the offline documentation can be found in $ANDROID_SDK/docs/.

MySQL Insert query doesn't work with WHERE clause

DO READ THIS AS WELL

It doesn't make sense... even literally

INSERT means add a new row and when you say WHERE you define which row are you talking about in the SQL.

So adding a new row is not possible with a condition on an existing row.

You have to choose from the following:

A. Use UPDATE instead of INSERT

B. Use INSERT and remove WHERE clause ( I am just saying it...) or if you are real bound to use INSERT and WHERE in a single statement it can be done only via INSERT..SELECT clause...

INSERT INTO Users( weight, desiredWeight ) 
SELECT FROM Users WHERE id = 1;

But this serves an entirely different purpose and if you have defined id as Primary Key this insert will be failure, otherwise a new row will be inserted with id = 1.

Table with fixed header and fixed column on pure css

I think this will help you: https://datatables.net/release-datatables/extensions/FixedHeader/examples/header_footer.html

In a nutshell, if you know how to create a dataTable, You just need to add this jQuery line to your bottom:

$(document).ready(function() {
    var table = $('#example').DataTable();

    new $.fn.dataTable.FixedHeader( table, {
        bottom: true
    } );
} );

bottom: true // is for making the Bottom header fixed as well.

Swift error : signal SIGABRT how to solve it

If you run into this in Xcode 10 you will have to clean before build. Or, switch to the legacy build system. File -> Workspace Settings... -> Build System: Legacy Build System.

How to update specific key's value in an associative array in PHP?

The best approach is using a lambda within "array_walk" native function to make the required changes:

    array_walk($data, function (&$value, $key) {
            if($key == 'transaction_date'){ 
                  $value = date('d/m/Y', $value); 
            }
    });

The value is updated in the array as it's passed with as a reference "&".

Disable double-tap "zoom" option in browser on touch devices

You should set the css property touch-action to none as described in this other answer https://stackoverflow.com/a/42288386/1128216

.disable-doubletap-to-zoom {
    touch-action: none;
}

estimating of testing effort as a percentage of development time

Judge by yesterday's weather. How long did it take last time? Are you trending longer or shorter? Each shop is different.

Most agile shops need a lot less time, have drastically fewer defects, and quicker time to resolve them because of TDD. Even so, most agile shops have some measurable time spent with testing/QC.

If this is the first test run for this application, then the answer is "lets see" followed by an attempt. It depends on how quick you can get questions answered, - how testable it is, - how many features/functions - how many defects are discovered, - how quickly issues are resolved, - how many times the code cycles through testing, and - how many times testing is blocked by bugs. There is no way to tell. You could call it 50% or 175% or more, and not be wrong. Why not make a rough guess and multiply by Pi? It won't be much worse than any other answer you can make up.

You should (must) know how long it takes now and whether it's getting faster or slower, and whether the coverage is increasing or decreasing. With those three bits of information, you should be able to guess quite well.

PopupWindow $BadTokenException: Unable to add window -- token null is not valid

A popup's parent can't itself be a popup. Both of their parents must be the same. So, if you create a popup inside a popup, you must save the parent's popup and make it a parent.

here's an example

convert from Color to brush

you can use this:

new SolidBrush(color)

where color is something like this:

Color.Red

or

Color.FromArgb(36,97,121))

or ...

How to search for an element in a golang slice

With a simple for loop:

for _, v := range myconfig {
    if v.Key == "key1" {
        // Found!
    }
}

Note that since element type of the slice is a struct (not a pointer), this may be inefficient if the struct type is "big" as the loop will copy each visited element into the loop variable.

It would be faster to use a range loop just on the index, this avoids copying the elements:

for i := range myconfig {
    if myconfig[i].Key == "key1" {
        // Found!
    }
}

Notes:

It depends on your case whether multiple configs may exist with the same key, but if not, you should break out of the loop if a match is found (to avoid searching for others).

for i := range myconfig {
    if myconfig[i].Key == "key1" {
        // Found!
        break
    }
}

Also if this is a frequent operation, you should consider building a map from it which you can simply index, e.g.

// Build a config map:
confMap := map[string]string{}
for _, v := range myconfig {
    confMap[v.Key] = v.Value
}

// And then to find values by key:
if v, ok := confMap["key1"]; ok {
    // Found
}

How can I lookup a Java enum from its String value?

since java 8 you can initialize the map in a single line and without static block

private static Map<String, Verbosity> stringMap = Arrays.stream(values())
                 .collect(Collectors.toMap(Enum::toString, Function.identity()));

Combining paste() and expression() functions in plot labels

Use substitute instead.

labNames <- c('xLab','yLab')
plot(c(1:10),
     xlab=substitute(paste(nn, x^2), list(nn=labNames[1])),
     ylab=substitute(paste(nn, y^2), list(nn=labNames[2])))

PostgreSQL, checking date relative to "today"

select * from mytable where mydate > now() - interval '1 year';

If you only care about the date and not the time, substitute current_date for now()

Change Select List Option background colour on hover in html

No, it's not possible.

It's really, if not use native selects, if you create custom select widget from html elements, t.e. "li".

How to center a window on the screen in Tkinter?

This works also in Python 3.x and centers the window on screen:

from tkinter import *

app = Tk()
app.eval('tk::PlaceWindow . center')
app.mainloop()

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled

In my case i have included jdbc api dependencies in the project so the "Hello World" not printed. After removing the below dependency it works like a charm.

       <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

Get time in milliseconds using C#

Use the Stopwatch class.

Provides a set of methods and properties that you can use to accurately measure elapsed time.

There is some good info on implementing it here:

Performance Tests: Precise Run Time Measurements with System.Diagnostics.Stopwatch

jQuery load first 3 elements, click "load more" to display next 5 elements

The expression $(document).ready(function() deprecated in jQuery3.

See working fiddle with jQuery 3 here

Take into account I didn't include the showless button.

Here's the code:

JS

$(function () {
    x=3;
    $('#myList li').slice(0, 3).show();
    $('#loadMore').on('click', function (e) {
        e.preventDefault();
        x = x+5;
        $('#myList li').slice(0, x).slideDown();
    });
});

CSS

#myList li{display:none;
}
#loadMore {
    color:green;
    cursor:pointer;
}
#loadMore:hover {
    color:black;
}

How to sort strings in JavaScript

I had been bothered about this for long, so I finally researched this and give you this long winded reason for why things are the way they are.

From the spec:

Section 11.9.4   The Strict Equals Operator ( === )

The production EqualityExpression : EqualityExpression === RelationalExpression
is evaluated as follows: 
- Let lref be the result of evaluating EqualityExpression.
- Let lval be GetValue(lref).
- Let rref be the result of evaluating RelationalExpression.
- Let rval be GetValue(rref).
- Return the result of performing the strict equality comparison 
  rval === lval. (See 11.9.6)

So now we go to 11.9.6

11.9.6   The Strict Equality Comparison Algorithm

The comparison x === y, where x and y are values, produces true or false. 
Such a comparison is performed as follows: 
- If Type(x) is different from Type(y), return false.
- If Type(x) is Undefined, return true.
- If Type(x) is Null, return true.
- If Type(x) is Number, then
...
- If Type(x) is String, then return true if x and y are exactly the 
  same sequence of characters (same length and same characters in 
  corresponding positions); otherwise, return false.

That's it. The triple equals operator applied to strings returns true iff the arguments are exactly the same strings (same length and same characters in corresponding positions).

So === will work in the cases when we're trying to compare strings which might have arrived from different sources, but which we know will eventually have the same values - a common enough scenario for inline strings in our code. For example, if we have a variable named connection_state, and we wish to know which one of the following states ['connecting', 'connected', 'disconnecting', 'disconnected'] is it in right now, we can directly use the ===.

But there's more. Just above 11.9.4, there is a short note:

NOTE 4     
  Comparison of Strings uses a simple equality test on sequences of code 
  unit values. There is no attempt to use the more complex, semantically oriented
  definitions of character or string equality and collating order defined in the 
  Unicode specification. Therefore Strings values that are canonically equal
  according to the Unicode standard could test as unequal. In effect this 
  algorithm assumes that both Strings are already in normalized form.

Hmm. What now? Externally obtained strings can, and most likely will, be weird unicodey, and our gentle === won't do them justice. In comes localeCompare to the rescue:

15.5.4.9   String.prototype.localeCompare (that)
    ...
    The actual return values are implementation-defined to permit implementers 
    to encode additional information in the value, but the function is required 
    to define a total ordering on all Strings and to return 0 when comparing
    Strings that are considered canonically equivalent by the Unicode standard. 

We can go home now.

tl;dr;

To compare strings in javascript, use localeCompare; if you know that the strings have no non-ASCII components because they are, for example, internal program constants, then === also works.

jquery $(window).height() is returning the document height

I had the same problem, and using this solved it.

var w = window.innerWidth;
var h = window.innerHeight;

IIS Express Windows Authentication

In addition to these great answers, in the context of an IISExpress dev environment, and in order to thwart the infamous "system.web/identity@impersonate" error, you can simply ensure the following setting is in place in your applicationhost.config file.

<configuration>
    <system.webServer>
        <validation validateIntegratedModeConfiguration="false" />
    </system.webServer>
</configuration>

This will allow you more flexibility during development and testing, though be sure you understand the implications of using this setting in a production environment before doing so.

Helpful Posts:

Xcode couldn't find any provisioning profiles matching

You can get this issue if Apple update their terms. Simply log into your dev account and accept any updated terms and you should be good (you will need to goto Xcode -> project->signing and capabilities and retry the certificate check. This should get you going if terms are the issue.

More than one file was found with OS independent path 'META-INF/LICENSE'

I had same error and i solved this error using this

Solution and Code

Add this package options in the app’s build.gradle

    packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/license.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/notice.txt'
        exclude 'META-INF/ASL2.0'
    }
   
}

jQuery - select the associated label element of a input field

You shouldn't rely on the order of elements by using prev or next. Just use the for attribute of the label, as it should correspond to the ID of the element you're currently manipulating:

var label = $("label[for='" + $(this).attr('id') + "']");

However, there are some cases where the label will not have for set, in which case the label will be the parent of its associated control. To find it in both cases, you can use a variation of the following:

var label = $('label[for="' + $(this).attr('id') + '"]');

if(label.length <= 0) {
    var parentElem = $(this).parent(),
        parentTagName = parentElem.get(0).tagName.toLowerCase();

    if(parentTagName == "label") {
        label = parentElem;
    }
}

I hope this helps!

Checkout another branch when there are uncommitted changes on the current branch

The correct answer is

git checkout -m origin/master

It merges changes from the origin master branch with your local even uncommitted changes.

SQL selecting rows by most recent date with two unique columns

So this isn't what the requester was asking for but it is the answer to "SQL selecting rows by most recent date".

Modified from http://wiki.lessthandot.com/index.php/Returning_The_Maximum_Value_For_A_Row

SELECT t.chargeId, t.chargeType, t.serviceMonth FROM( 
    SELECT chargeId,MAX(serviceMonth) AS serviceMonth
    FROM invoice
    GROUP BY chargeId) x 
    JOIN invoice t ON x.chargeId =t.chargeId
    AND x.serviceMonth = t.serviceMonth

Formula to check if string is empty in Crystal Reports

If IsNull({TABLE.FIELD1}) then "NULL" +',' + {TABLE.FIELD2} else {TABLE.FIELD1} + ', ' + {TABLE.FIELD2}

Here I put NULL as string to display the string value NULL in place of the null value in the data field. Hope you understand.

Failed to locate the winutils binary in the hadoop binary path

I was getting the same issue in windows. I fixed it by

  • Downloading hadoop-common-2.2.0-bin-master from link.
  • Create a user variable HADOOP_HOME in Environment variable and assign the path of hadoop-common bin directory as a value.
  • You can verify it by running hadoop in cmd.
  • Restart the IDE and Run it.

Can Javascript read the source of any web page?

Despite many comments to the contrary I believe that it is possible to overcome the same origin requirement with simple JavaScript.

I am not claiming that the following is original because I believe I saw something similar elsewhere a while ago.

I have only tested this with Safari on a Mac.

The following demonstration fetches the page in the base tag and and moves its innerHTML to a new window. My script adds html tags but with most modern browsers this could be avoided by using outerHTML.

<html>
<head>
<base href='http://apod.nasa.gov/apod/'>
<title>test</title>
<style>
body { margin: 0 }
textarea { outline: none; padding: 2em; width: 100%; height: 100% }
</style>
</head>
<body onload="w=window.open('#'); x=document.getElementById('t'); a='<html>\n'; b='\n</html>'; setTimeout('x.innerHTML=a+w.document.documentElement.innerHTML+b; w.close()',2000)">
<textarea id=t></textarea>
</body>
</html>

Declaring abstract method in TypeScript

The name property is marked as protected. This was added in TypeScript 1.3 and is now firmly established.

The makeSound method is marked as abstract, as is the class. You cannot directly instantiate an Animal now, because it is abstract. This is part of TypeScript 1.6, which is now officially live.

abstract class Animal {
    constructor(protected name: string) { }

    abstract makeSound(input : string) : string;

    move(meters) {
        alert(this.name + " moved " + meters + "m.");
    }
}

class Snake extends Animal {
    constructor(name: string) { super(name); }

    makeSound(input : string) : string {
        return "sssss"+input;
    }

    move() {
        alert("Slithering...");
        super.move(5);
    }
}

The old way of mimicking an abstract method was to throw an error if anyone used it. You shouldn't need to do this any more once TypeScript 1.6 lands in your project:

class Animal {
    constructor(public name) { }
    makeSound(input : string) : string {
        throw new Error('This method is abstract');
    }
    move(meters) {
        alert(this.name + " moved " + meters + "m.");
    }
}

class Snake extends Animal {
    constructor(name) { super(name); }
    makeSound(input : string) : string {
        return "sssss"+input;
    }
    move() {
        alert("Slithering...");
        super.move(5);
    }
}

What does asterisk * mean in Python?

A single star means that the variable 'a' will be a tuple of extra parameters that were supplied to the function. The double star means the variable 'kw' will be a variable-size dictionary of extra parameters that were supplied with keywords.

Although the actual behavior is spec'd out, it still sometimes can be very non-intuitive. Writing some sample functions and calling them with various parameter styles may help you understand what is allowed and what the results are.

def f0(a)
def f1(*a)
def f2(**a)
def f3(*a, **b)
etc...

When to use malloc for char pointers

Use malloc() when you don't know the amount of memory needed during compile time. In case if you have read-only strings then you can use const char* str = "something"; . Note that the string is most probably be stored in a read-only memory location and you'll not be able to modify it. On the other hand if you know the string during compiler time then you can do something like: char str[10]; strcpy(str, "Something"); Here the memory is allocated from stack and you will be able to modify the str. Third case is allocating using malloc. Lets say you don'r know the length of the string during compile time. Then you can do char* str = malloc(requiredMem); strcpy(str, "Something"); free(str);

How do I get into a Docker container's shell?

In some cases your image can be Alpine-based. In this case it will throw:

OCI runtime exec failed: exec failed: container_linux.go:348: starting container process caused "exec: \"bash\": executable file not found in $PATH": unknown

Because /bin/bash doesn't exist. Instead of this you should use:

docker exec -it 9f7d99aa6625 ash

or

docker exec -it 9f7d99aa6625 sh

How to get script of SQL Server data?

I know this has been answered already, but I am here to offer a word of warning. We recently received a database from a client that has a cyclical foreign key reference. The SQL Server script generator refuses to generate the data for databases with cyclical references.

Regex to match string containing two names in any order

Explanation of command that i am going to write:-

. means any character, digit can come in place of .

* means zero or more occurrences of thing written just previous to it.

| means 'or'.

So,

james.*jack

would search james , then any number of character until jack comes.

Since you want either jack.*james or james.*jack

Hence Command:

jack.*james|james.*jack

How to access property of anonymous type in C#?

The accepted answer correctly describes how the list should be declared and is highly recommended for most scenarios.

But I came across a different scenario, which also covers the question asked. What if you have to use an existing object list, like ViewData["htmlAttributes"] in MVC? How can you access its properties (they are usually created via new { @style="width: 100px", ... })?

For this slightly different scenario I want to share with you what I found out. In the solutions below, I am assuming the following declaration for nodes:

List<object> nodes = new List<object>();

nodes.Add(
new
{
    Checked = false,
    depth = 1,
    id = "div_1" 
});

1. Solution with dynamic

In C# 4.0 and higher versions, you can simply cast to dynamic and write:

if (nodes.Any(n => ((dynamic)n).Checked == false))
    Console.WriteLine("found a  not checked  element!");

Note: This is using late binding, which means it will recognize only at runtime if the object doesn't have a Checked property and throws a RuntimeBinderException in this case - so if you try to use a non-existing Checked2 property you would get the following message at runtime: "'<>f__AnonymousType0<bool,int,string>' does not contain a definition for 'Checked2'".

2. Solution with reflection

The solution with reflection works both with old and new C# compiler versions. For old C# versions please regard the hint at the end of this answer.

Background

As a starting point, I found a good answer here. The idea is to convert the anonymous data type into a dictionary by using reflection. The dictionary makes it easy to access the properties, since their names are stored as keys (you can access them like myDict["myProperty"]).

Inspired by the code in the link above, I created an extension class providing GetProp, UnanonymizeProperties and UnanonymizeListItems as extension methods, which simplify access to anonymous properties. With this class you can simply do the query as follows:

if (nodes.UnanonymizeListItems().Any(n => (bool)n["Checked"] == false))
{
    Console.WriteLine("found a  not checked  element!");
}

or you can use the expression nodes.UnanonymizeListItems(x => (bool)x["Checked"] == false).Any() as if condition, which filters implicitly and then checks if there are any elements returned.

To get the first object containing "Checked" property and return its property "depth", you can use:

var depth = nodes.UnanonymizeListItems()
             ?.FirstOrDefault(n => n.Contains("Checked")).GetProp("depth");

or shorter: nodes.UnanonymizeListItems()?.FirstOrDefault(n => n.Contains("Checked"))?["depth"];

Note: If you have a list of objects which don't necessarily contain all properties (for example, some do not contain the "Checked" property), and you still want to build up a query based on "Checked" values, you can do this:

if (nodes.UnanonymizeListItems(x => { var y = ((bool?)x.GetProp("Checked", true)); 
                                      return y.HasValue && y.Value == false;}).Any())
{
    Console.WriteLine("found a  not checked   element!");
}

This prevents, that a KeyNotFoundException occurs if the "Checked" property does not exist.


The class below contains the following extension methods:

  • UnanonymizeProperties: Is used to de-anonymize the properties contained in an object. This method uses reflection. It converts the object into a dictionary containing the properties and its values.
  • UnanonymizeListItems: Is used to convert a list of objects into a list of dictionaries containing the properties. It may optionally contain a lambda expression to filter beforehand.
  • GetProp: Is used to return a single value matching the given property name. Allows to treat not-existing properties as null values (true) rather than as KeyNotFoundException (false)

For the examples above, all that is required is that you add the extension class below:

public static class AnonymousTypeExtensions
{
    // makes properties of object accessible 
    public static IDictionary UnanonymizeProperties(this object obj)
    {
        Type type = obj?.GetType();
        var properties = type?.GetProperties()
               ?.Select(n => n.Name)
               ?.ToDictionary(k => k, k => type.GetProperty(k).GetValue(obj, null));
        return properties;
    }
    
    // converts object list into list of properties that meet the filterCriteria
    public static List<IDictionary> UnanonymizeListItems(this List<object> objectList, 
                    Func<IDictionary<string, object>, bool> filterCriteria=default)
    {
        var accessibleList = new List<IDictionary>();
        foreach (object obj in objectList)
        {
            var props = obj.UnanonymizeProperties();
            if (filterCriteria == default
               || filterCriteria((IDictionary<string, object>)props) == true)
            { accessibleList.Add(props); }
        }
        return accessibleList;
    }

    // returns specific property, i.e. obj.GetProp(propertyName)
    // requires prior usage of AccessListItems and selection of one element, because
    // object needs to be a IDictionary<string, object>
    public static object GetProp(this object obj, string propertyName, 
                                 bool treatNotFoundAsNull = false)
    {
        try 
        {
            return ((System.Collections.Generic.IDictionary<string, object>)obj)
                   ?[propertyName];
        }
        catch (KeyNotFoundException)
        {
            if (treatNotFoundAsNull) return default(object); else throw;
        }
    }
}

Hint: The code above is using the null-conditional operators, available since C# version 6.0 - if you're working with older C# compilers (e.g. C# 3.0), simply replace ?. by . and ?[ by [ everywhere (and do the null-handling traditionally by using if statements or catch NullReferenceExceptions), e.g.

var depth = nodes.UnanonymizeListItems()
            .FirstOrDefault(n => n.Contains("Checked"))["depth"];

As you can see, the null-handling without the null-conditional operators would be cumbersome here, because everywhere you removed them you have to add a null check - or use catch statements where it is not so easy to find the root cause of the exception resulting in much more - and hard to read - code.

If you're not forced to use an older C# compiler, keep it as is, because using null-conditionals makes null handling much easier.

Note: Like the other solution with dynamic, this solution is also using late binding, but in this case you're not getting an exception - it will simply not find the element if you're referring to a non-existing property, as long as you keep the null-conditional operators.

What might be useful for some applications is that the property is referred to via a string in solution 2, hence it can be parameterized.

Is there a Google Chrome-only CSS hack?

To work only chrome or safari, try it:

@media screen and (-webkit-min-device-pixel-ratio:0) { 
/* Safari and Chrome */
.myClass {
 color:red;
}

/* Safari only override */
::i-block-chrome,.myClass {
 color:blue;
}}

How can you export the Visual Studio Code extension list?

Benny's answer on Windows with the Linux subsystem:

code --list-extensions | wsl xargs -L 1 echo code --install-extension

Laravel Eloquent compare date from datetime field

You can use this

whereDate('date', '=', $date)

If you give whereDate then compare only date from datetime field.

List submodules in a Git repository

Use:

$ git submodule

It will list all the submodules in the specified Git repository.

php Replacing multiple spaces with a single space

Use preg_replace() and instead of [ \t\n\r] use \s:

$output = preg_replace('!\s+!', ' ', $input);

From Regular Expression Basic Syntax Reference:

\d, \w and \s

Shorthand character classes matching digits, word characters (letters, digits, and underscores), and whitespace (spaces, tabs, and line breaks). Can be used inside and outside character classes.

TNS Protocol adapter error while starting Oracle SQL*Plus

Ensure the OracleService is running. I keep running into this error, but when I go into Services, find OracleServiceXE and manually start it, the problem is resolved. I have it set to start automatically, but sometimes it just seems to stop on its own; at least, I can't find anything I am doing to stop it.

"Unable to find remote helper for 'https'" during git clone

CentOS Minimal usually install version 1.8 git by yum install gitcommand.

The best way is to build & install it from source code. Current version is 2.18.0.

  1. Download the source code from https://mirrors.edge.kernel.org/pub/software/scm/git/ or curl -o git-2.18.0.tar.gz https://mirrors.edge.kernel.org/pub/software/scm/git/git-2.18.0.tar.gz

  2. Unzip by tar -zxf git-2.18.0.tar.gz && cd git-2.18.0

  3. Install the dependency package by executing yum install autoconf curl-devel expat-devel gettext-devel openssl-devel perl-devel zlib-devel asciidoc xmlto openjade perl* texinfo

  4. Install docbook2X, it's not in the rpm repository. Download and install by

    $ curl -o docbook2X-0.8.8-17.el7.x86_64.rpm http://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/d/docbook2X-0.8.8-17.el7.x86_64.rpm $ rpm -Uvh docbook2X-0.8.8-17.el7.x86_64.rpm

And make a unix link name:

ln -s /usr/bin/db2x_docbook2texi /usr/bin/docbook2x-texi
  1. Compile and install, reference to https://git-scm.com/book/en/v2/Getting-Started-Installing-Git

    $ make configure $ ./configure --prefix=/usr $ make all doc info $ sudo make install install-doc install-html install-info

  2. Reboot your server (If not, you may encounter Unable to find remote helper for 'https' error)

    $ reboot now

  3. Test:

    $ git clone https://github.com/volnet/v-labs.git $ cd v-labs $ touch test.txt $ git add . $ git commit -m "test git install" $ git push -u

How to get current domain name in ASP.NET

Try this:

@Request.Url.GetLeftPart(UriPartial.Authority)

getOutputStream() has already been called for this response

Ok, you should be using a servlet not a JSP but if you really need to... add this directive at the top of your page:

<%@ page trimDirectiveWhitespaces="true" %>

Or in the jsp-config section your web.xml

<jsp-config>
  <jsp-property-group>
    <url-pattern>*.jsp</url-pattern>
    <trim-directive-whitespaces>true</trim-directive-whitespaces>
  </jsp-property-group>
</jsp-config>

Also flush/close the OutputStream and return when done.

dataOutput.flush();
dataOutput.close();
return;

Split array into chunks of N length

It could be something like that:

_x000D_
_x000D_
var a = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'];

var arrays = [], size = 3;
    
while (a.length > 0)
  arrays.push(a.splice(0, size));

console.log(arrays);
_x000D_
_x000D_
_x000D_

See splice Array's method.

FB OpenGraph og:image not pulling images (possibly https?)

In my case, it seems that the crawler is just having a bug. I've tried:

  • Changing links to http only
  • Removing end white space
  • Switching back to http completely
  • Reinstalling the website
  • Installing a bunch of OG plugins (I use WordPress)
  • Suspecting the server has a weird misconfiguration that blocks the bots (because all the OG checkers are unable to fetch tags, and other requests to my sites are unstable)

None of these works. This costed me a week. And suddenly out of nowhere it seems to work again.

Here are my research, if someone meets this problem again:

Also, there are more checkers other than the Facebook's Object Debugger for you to check: OpenGraphCheck.com, Abhinay Rathore's Open Graph Tester, Iframely's Embed Codes, Card Validator | Twitter Developers.

Find the location of a character in string

Here's another straightforward alternative.

> which(strsplit(string, "")[[1]]=="2")
[1]  4 24

What is __main__.py?

You create __main__.py in yourpackage to make it executable as:

$ python -m yourpackage

How to set editable true/false EditText in Android programmatically?

editText.setFocusable(false);
editText.setClickable(false);

Pass table as parameter into sql server UDF

Step 1: Create a Type as Table with name TableType that will accept a table having one varchar column

create type TableType
as table ([value] varchar(100) null)

Step 2: Create a function that will accept above declared TableType as Table-Valued Parameter and String Value as Separator

create function dbo.fn_get_string_with_delimeter (@table TableType readonly,@Separator varchar(5))
returns varchar(500)
As
begin

    declare @return varchar(500)

    set @return = stuff((select @Separator + value from @table for xml path('')),1,1,'')

    return @return

end

Step 3: Pass table with one varchar column to the user-defined type TableType and ',' as separator in the function

select dbo.fn_get_string_with_delimeter(@tab, ',')

When to use static methods

No, static methods aren't associated with an instance; they belong to the class. Static methods are your second example; instance methods are the first.

@ variables in Ruby on Rails

A local variable is only accessible from within the block of it's initialization. Also a local variable begins with a lower case letter (a-z) or underscore (_).

And instance variable is an instance of self and begins with a @ Also an instance variable belongs to the object itself. Instance variables are the ones that you perform methods on i.e. .send etc

example:

@user = User.all

The @user is the instance variable

And Uninitialized instance variables have a value of Nil

Sending multipart/formdata with jQuery.ajax

I just built this function based on some info I read.

Use it like using .serialize(), instead just put .serializefiles();.
Working here in my tests.

//USAGE: $("#form").serializefiles();
(function($) {
$.fn.serializefiles = function() {
    var obj = $(this);
    /* ADD FILE TO PARAM AJAX */
    var formData = new FormData();
    $.each($(obj).find("input[type='file']"), function(i, tag) {
        $.each($(tag)[0].files, function(i, file) {
            formData.append(tag.name, file);
        });
    });
    var params = $(obj).serializeArray();
    $.each(params, function (i, val) {
        formData.append(val.name, val.value);
    });
    return formData;
};
})(jQuery);

Inserting code in this LaTeX document with indentation

Use Minted.

It's a package that facilitates expressive syntax highlighting in LaTeX using the powerful Pygments library. The package also provides options to customize the highlighted source code output using fancyvrb.

It's much more evolved and customizable than any other package!

Why is a div with "display: table-cell;" not affected by margin?

Table cells don't respect margin, but you could use transparent borders instead:

div {
  display: table-cell;
  border: 5px solid transparent;
}

Note: you can't use percentages here... :(

Specifying ssh key in ansible playbook file

The variable name you're looking for is ansible_ssh_private_key_file.

You should set it at 'vars' level:

  • in the inventory file:

    myHost ansible_ssh_private_key_file=~/.ssh/mykey1.pem
    myOtherHost ansible_ssh_private_key_file=~/.ssh/mykey2.pem
    
  • in the host_vars:

    # hosts_vars/myHost.yml
    ansible_ssh_private_key_file: ~/.ssh/mykey1.pem
    
    # hosts_vars/myOtherHost.yml
    ansible_ssh_private_key_file: ~/.ssh/mykey2.pem
    
  • in a group_vars file if you use the same key for a group of hosts

  • in the vars section of your play:

    - hosts: myHost
      remote_user: ubuntu
      vars_files:
        - vars.yml
      vars:
        ansible_ssh_private_key_file: "{{ key1 }}"
      tasks:
        - name: Echo a hello message
          command: echo hello
    

Inventory documentation

Parse DateTime string in JavaScript

This function handles also the invalid 29.2.2001 date.

function parseDate(str) {
    var dateParts = str.split(".");
    if (dateParts.length != 3)
        return null;
    var year = dateParts[2];
    var month = dateParts[1];
    var day = dateParts[0];

    if (isNaN(day) || isNaN(month) || isNaN(year))
        return null;

    var result = new Date(year, (month - 1), day);
    if (result == null)
        return null;
    if (result.getDate() != day)
        return null;
    if (result.getMonth() != (month - 1))
        return null;
    if (result.getFullYear() != year)
        return null;

    return result;
}

How to get a cross-origin resource sharing (CORS) post request working

Took me some time to find the solution.

In case your server response correctly and the request is the problem, you should add withCredentials: true to the xhrFields in the request:

$.ajax({
    url: url,
    type: method,
    // This is the important part
    xhrFields: {
        withCredentials: true
    },
    // This is the important part
    data: data,
    success: function (response) {
        // handle the response
    },
    error: function (xhr, status) {
        // handle errors
    }
});

Note: jQuery >= 1.5.1 is required

When to use single quotes, double quotes, and backticks in MySQL

SQL servers and MySQL, PostgreySQL, Oracle don't understand double quotes("). Thus your query should be free from double quotes(") and should only use single quotes(').

Back-trip(`) is optional to use in SQL and is used for table name, db name and column names.

If you are trying to write query in your back-end to call MySQL then you can use double quote(") or single quotes(') to assign query to a variable like:

let query = "select id, name from accounts";
//Or
let query = 'select id, name from accounts';

If ther's a where statement in your query and/or trying to insert a value and/or an update of value which is string use single quote(') for these values like:

let querySelect = "select id, name from accounts where name = 'John'";
let queryUpdate = "update accounts set name = 'John' where id = 8";
let queryInsert = "insert into accounts(name) values('John')";

//Please not that double quotes are only to be used in assigning string to our variable not in the query
//All these below will generate error

let querySelect = 'select id, name from accounts where name = "John"';
let queryUpdate = 'update accounts set name = "John" where id = 8';
let queryInsert = 'insert into accounts(name) values("John")';

//As MySQL or any SQL doesn't understand double quotes("), these all will generate error.

If you want to stay out of this confusion when to use double quotes(") and single quotes('), would recommend to stick with single quotes(') this will include backslash() like:

let query = 'select is, name from accounts where name = \'John\'';

Problem with double(") or single(') quotes arise when we had to assign some value dynamic and perform some string concatenation like:

let query = "select id, name from accounts where name = " + fName + " " + lName;
//This will generate error as it must be like name = 'John Smith' for SQL
//However our statement made it like name = John Smith

//In order to resolve such errors use
let query = "select id, name from accounts where name = '" + fName + " " + lName + "'";

//Or using backslash(\)
let query = 'select id, name from accounts where name = \'' + fName + ' ' + lName + '\'';

If need further clearance do follow quotes in JavaScript

Unable to locate an executable at "/usr/bin/java/bin/java" (-1)

In MacOS Catalina, run

sudo nano ~/.bash_profile

In bash_profile, add:

export JAVA_HOME=$(/usr/libexec/java_home)
source ~/.bash_profile

Verify by running java --version

How to find topmost view controller on iOS

And another Swift solution

extension UIViewController {
    static var topmostViewController: UIViewController? {
        return UIApplication.sharedApplication().keyWindow?.topmostViewController
    }

    var topmostViewController: UIViewController? {
        return presentedViewController?.topmostViewController ?? self
    }
}

extension UINavigationController {
    override var topmostViewController: UIViewController? {
        return visibleViewController?.topmostViewController
    }
}

extension UITabBarController {
    override var topmostViewController: UIViewController? {
        return selectedViewController?.topmostViewController
    }
}

extension UIWindow {
    var topmostViewController: UIViewController? {
        return rootViewController?.topmostViewController
    }
}

How to determine previous page URL in Angular?

You can use Location as mentioned here.

Here's my code if the link opened on new tab

navBack() {
    let cur_path = this.location.path();
    this.location.back();
    if (cur_path === this.location.path())
     this.router.navigate(['/default-route']);    
  }

Required imports

import { Router } from '@angular/router';
import { Location } from '@angular/common';

How can I correctly format currency using jquery?

Use jquery.inputmask 3.x. See demos here

Include files:

<script src="/assets/jquery.inputmask.js" type="text/javascript"></script>
<script src="/assets/jquery.inputmask.extensions.js" type="text/javascript"></script>
<script src="/assets/jquery.inputmask.numeric.extensions.js" type="text/javascript"></script>

And code as

$(selector).inputmask('decimal',
  { 'alias': 'numeric',
    'groupSeparator': '.',
    'autoGroup': true,
    'digits': 2,
    'radixPoint': ",",
    'digitsOptional': false,
    'allowMinus': false,
    'prefix': '$ ',
    'placeholder': '0'
  }
);

Highlights:

  • easy to use
  • optional parts anywere in the mask
  • possibility to define aliases which hide complexity
  • date / datetime masks
  • numeric masks
  • lots of callbacks
  • non-greedy masks
  • many features can be enabled/disabled/configured by options
  • supports readonly/disabled/dir="rtl" attributes
  • support data-inputmask attribute(s)
  • multi-mask support
  • regex-mask support
  • dynamic-mask support
  • preprocessing-mask support
  • value formatting / validating without input element

PHP append one array to another (not array_push or +)

How about this:

$appended = $a + $b;

How do I get the height of a div's full content with jQuery?

You can get it with .outerHeight().

Sometimes, it will return 0. For the best results, you can call it in your div's ready event.

To be safe, you should not set the height of the div to x. You can keep its height auto to get content populated properly with the correct height.

$('#x').ready( function(){
// alerts the height in pixels
alert($('#x').outerHeight());
})

You can find a detailed post here.

Where can I get a list of Ansible pre-defined variables?

Some variables are not available on every host, e.g. ansible_domain and domain. If the situation needs to be debugged, I login to the server and issue:

user@server:~$ ansible -m setup localhost | grep domain
 [WARNING]: provided hosts list is empty, only localhost is available
    "ansible_domain": "prd.example.com",

Change location of log4j.properties

You must use log4j.configuration property like this:

java -Dlog4j.configuration=file:/path/to/log4j.properties myApp

If the file is under the class-path (inside ./src/main/resources/ folder), you can omit the file:// protocol:

java -Dlog4j.configuration=path/to/log4j.properties myApp

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

Based on zenpoy's answer:

import Image
import numpy

def image2pixelarray(filepath):
    """
    Parameters
    ----------
    filepath : str
        Path to an image file

    Returns
    -------
    list
        A list of lists which make it simple to access the greyscale value by
        im[y][x]
    """
    im = Image.open(filepath).convert('L')
    (width, height) = im.size
    greyscale_map = list(im.getdata())
    greyscale_map = numpy.array(greyscale_map)
    greyscale_map = greyscale_map.reshape((height, width))
    return greyscale_map

Count elements with jQuery

var count_elements = $('.class').length;

From: http://api.jquery.com/size/

The .size() method is functionally equivalent to the .length property; however, the .length property is preferred because it does not have the overhead of a function call.

Please see:

http://api.jquery.com/size/

http://api.jquery.com/length/

How to use Console.WriteLine in ASP.NET (C#) during debug?

If for whatever reason you'd like to catch the output of Console.WriteLine, you CAN do this:

protected void Application_Start(object sender, EventArgs e)
{
    var writer = new LogWriter();
    Console.SetOut(writer);
}

public class LogWriter : TextWriter
{
    public override void WriteLine(string value)
    {
        //do whatever with value
    }

    public override Encoding Encoding
    {
        get { return Encoding.Default; }
    }
}

How to wait for a number of threads to complete?

You put all threads in an array, start them all, and then have a loop

for(i = 0; i < threads.length; i++)
  threads[i].join();

Each join will block until the respective thread has completed. Threads may complete in a different order than you joining them, but that's not a problem: when the loop exits, all threads are completed.

Access-control-allow-origin with multiple domains

There can only be one Access-Control-Allow-Origin response header, and that header can only have one origin value. Therefore, in order to get this to work, you need to have some code that:

  1. Grabs the Origin request header.
  2. Checks if the origin value is one of the whitelisted values.
  3. If it is valid, sets the Access-Control-Allow-Origin header with that value.

I don't think there's any way to do this solely through the web.config.

if (ValidateRequest()) {
    Response.Headers.Remove("Access-Control-Allow-Origin");
    Response.AddHeader("Access-Control-Allow-Origin", Request.UrlReferrer.GetLeftPart(UriPartial.Authority));

    Response.Headers.Remove("Access-Control-Allow-Credentials");
    Response.AddHeader("Access-Control-Allow-Credentials", "true");

    Response.Headers.Remove("Access-Control-Allow-Methods");
    Response.AddHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
}

RegEx to make sure that the string contains at least one lower case char, upper case char, digit and symbol

You can match those three groups separately, and make sure that they all present. Also, [^\w] seems a bit too broad, but if that's what you want you might want to replace it with \W.

printing a two dimensional array in python

for i in A:
    print('\t'.join(map(str, i)))

How should I set the default proxy to use default credentials?

This will force the DefaultWebProxy to use default credentials, similar effect as done through UseDefaultCredentials = true.

WebRequest.DefaultWebProxy.Credentials = CredentialCache.DefaultNetworkCredentials;

Hence all newly created WebRequest instances will use default proxy which has been configured to use proxy's default credentials.

Download file from web in Python 3

You can use wget which is popular downloading shell tool for that. https://pypi.python.org/pypi/wget This will be the simplest method since it does not need to open up the destination file. Here is an example.

import wget
url = 'https://i1.wp.com/python3.codes/wp-content/uploads/2015/06/Python3-powered.png?fit=650%2C350'  
wget.download(url, '/Users/scott/Downloads/cat4.jpg') 

How do I target only Internet Explorer 10 for certain situations like Internet Explorer-specific CSS or Internet Explorer-specific JavaScript code?

Internet Explorer 10 does not attempt to read conditional comments anymore. This means it will treat conditional comments just like any other browser would: as regular HTML comments, meant to be ignored entirely. Looking at the markup given in the question as an example, all browsers including IE10 will ignore the comment portions, highlighted gray, entirely. The HTML5 standard makes no mention of conditional comment syntax, and this is exactly why they have chosen to stop supporting it in IE10.

Note, however, that conditional compilation in JScript is still supported, as shown in the comments as well as the more recent answers. It's not going away in the final release either, unlike jQuery.browser. And of course, it goes without saying that user-agent sniffing remains as fragile as ever and should never be used under any circumstances.

If you really must target IE10, either use conditional compilation which may still see support in the near future, or — if you can help it — use a feature detection library such as Modernizr instead of (or in conjunction with) browser detection. Unless your use case requires noscript or accommodating IE10 on the server side, user-agent sniffing is going to be more of a headache than a viable option.

Sounds pretty cumbersome, but remember that as a modern browser that's highly conformant to today's Web standards1, assuming you've written interoperable code that is highly standards-compliant, you shouldn't have to set aside special code for IE10 unless absolutely necessary, i.e. it's supposed to resemble other browsers in terms of behavior and rendering.2 And it sounds far-fetched, given IE's history, but how many times have you expected Firefox or Chrome to behave the same way only to be met with dismay?

If you do have a legitimate reason to be targeting certain browsers, by all means sniff them out with the other tools given to you. I'm just saying that you're going to be much more hard-pressed to find such a reason today than what it used to be, and it's really just not something you can rely on.


1 Not only IE10, but IE9, and even IE8 which handles most of the mature CSS2.1 standard far better than Chrome, simply because IE8 was so focused on standards compliance (at which time CSS2.1 was already pretty stable with only minor differences from today's recommendation) while Chrome seems to be little more than a half-polished tech demo of cutting-edge pseudo-standards.

2 And I may be biased when I say this, but it sure as hell does. If your code works in other browsers but not IE, the odds that it's an issue with your own code rather than IE10 are far better compared to, say, 3 years ago, with previous versions of IE. Again, I may be biased, but let's be honest: aren't you too? Just look at your comments.

Recommended way to insert elements into map

map[key] = value is provided for easier syntax. It is easier to read and write.

The reason for which you need to have default constructor is that map[key] is evaluated before assignment. If key wasn't present in map, new one is created (with default constructor) and reference to it is returned from operator[].

Add rows to CSV File in powershell

I know this is an old thread but it was the first I found when searching. The += solution did not work for me. The code that I did get to work is as below.

#this bit creates the CSV if it does not already exist
$headers = "Name", "Primary Type"
$psObject = New-Object psobject
foreach($header in $headers)
{
 Add-Member -InputObject $psobject -MemberType noteproperty -Name $header -Value ""
}
$psObject | Export-Csv $csvfile -NoTypeInformation

#this bit appends a new row to the CSV file
$bName = "My Name"
$bPrimaryType = "My Primary Type"
    $hash = @{
             "Name" =  $bName
             "Primary Type" = $bPrimaryType
              }

$newRow = New-Object PsObject -Property $hash
Export-Csv $csvfile -inputobject $newrow -append -Force

I was able to use this as a function to loop through a series of arrays and enter the contents into the CSV file.

It works in powershell 3 and above.

C++ Returning reference to local variable

A good thing to remember are these simple rules, and they apply to both parameters and return types...

  • Value - makes a copy of the item in question.
  • Pointer - refers to the address of the item in question.
  • Reference - is literally the item in question.

There is a time and place for each, so make sure you get to know them. Local variables, as you've shown here, are just that, limited to the time they are locally alive in the function scope. In your example having a return type of int* and returning &i would have been equally incorrect. You would be better off in that case doing this...

void func1(int& oValue)
{
    oValue = 1;
}

Doing so would directly change the value of your passed in parameter. Whereas this code...

void func1(int oValue)
{
    oValue = 1;
}

would not. It would just change the value of oValue local to the function call. The reason for this is because you'd actually be changing just a "local" copy of oValue, and not oValue itself.

Sum values in foreach loop php

$total=0;
foreach($group as $key=>$value)
{
   echo $key. " = " .$value. "<br>"; 
   $total+= $value;
}
echo $total;

Windows cannot find 'http:/.127.0.0.1:%HTTPPORT%/apex/f?p=4950'. Make sure you typed the name correctly, and then try again

Try out this url it is work for me

http://127.0.0.1:8080/apex/f?p=4950:1:1615033681376854

  1. Windows->Services and restarted some of services(OracleJobSchedulerXE,OracleMTSRecoveryService,OracleServiceXE,OracleXEClrAgent,OracleXETNSListener) and it works for me.enter image description here

Url.Action parameters?

The following is the correct overload (in your example you are missing a closing } to the routeValues anonymous object so your code will throw an exception):

<a href="<%: Url.Action("GetByList", "Listing", new { name = "John", contact = "calgary, vancouver" }) %>">
    <span>People</span>
</a>

Assuming you are using the default routes this should generate the following markup:

<a href="/Listing/GetByList?name=John&amp;contact=calgary%2C%20vancouver">
    <span>People</span>
</a>

which will successfully invoke the GetByList controller action passing the two parameters:

public ActionResult GetByList(string name, string contact) 
{
    ...
}

What is the easiest/best/most correct way to iterate through the characters of a string in Java?

Two options

for(int i = 0, n = s.length() ; i < n ; i++) { 
    char c = s.charAt(i); 
}

or

for(char c : s.toCharArray()) {
    // process c
}

The first is probably faster, then 2nd is probably more readable.

Reading output of a command into an array in Bash

Here is an example. Imagine that you are going to put the files and directory names (under the current folder) to an array and count its items. The script would be like;

my_array=( `ls` )
my_array_length=${#my_array[@]}
echo $my_array_length

Or, you can iterate over this array by adding the following script:

for element in "${my_array[@]}"
do
   echo "${element}"
done

Please note that this is the core concept and the input is considered to be sanitized before, i.e. removing extra characters, handling empty Strings, and etc. (which is out of the topic of this thread).

How can I perform a short delay in C# without using sleep?

Sorry for awakening an old question like this. But I think what the original author wanted as an answer was:

You need to force your program to make the graphic update after you make the change to the textbox1. You can do that by invoking Update();

textBox1.Text += "\r\nThread Sleeps!";
textBox1.Update();
System.Threading.Thread.Sleep(4000);
textBox1.Text += "\r\nThread awakens!";
textBox1.Update();

Normally this will be done automatically when the thread is done. Ex, you press a button, changes are made to the text, thread dies, and then .Update() is fired and you see the changes. (I'm not an expert so I cant really tell you when its fired, but its something similar to this any way.)

In this case, you make a change, pause the thread, and then change the text again, and when the thread finally dies the .Update() is fired. This resulting in you only seeing the last change made to the text.

You would experience the same issue if you had a long execution between the text changes.

rbenv not changing ruby version

You could try using chruby? chruby does not rely on shims, instead it only modifies PATH, GEM_HOME, GEM_PATH.

Inserting a Python datetime.datetime object into MySQL

Try using now.date() to get a Date object rather than a DateTime.

If that doesn't work, then converting that to a string should work:

now = datetime.datetime(2009,5,5)
str_now = now.date().isoformat()
cursor.execute('INSERT INTO table (name, id, datecolumn) VALUES (%s,%s,%s)', ('name',4,str_now))

Sql query to insert datetime in SQL Server

Management studio creates scripts like:

insert table1 (foodate) values(CAST(N'2012-06-18 10:34:09.000' AS DateTime))

How to convert Json array to list of objects in c#

Your data structure and your JSON do not match.

Your JSON is this:

{
    "JsonValues":{
        "id": "MyID",
        ...
    }
}

But the data structure you try to serialize it to is this:

class ValueSet
{
    [JsonProperty("id")]
    public string id
    {
        get;
        set;
    }
    ...
}

You are skipping a step: Your JSON is a class that has one property named JsonValues, which has an object of your ValueSet data structure as value.

Also inside your class your JSON is this:

"values": { ... }

Your data structure is this:

[JsonProperty("values")]
public List<Value> values
{
    get;
    set;
}

Note that { .. } in JSON defines an object, where as [ .. ] defines an array. So according to your JSON you don't have a bunch of values, but you have one values object with the properties value1 and value2 of type Value.

Since the deserializer expects an array but gets an object instead, it does the least non-destructive (Exception) thing it could do: skip the value. Your property values remains with it's default value: null.

If you can: Adjust your JSON. The following would match your data structure and is most likely what you actually want:

{
    "id": "MyID",

     "values": [
         {
            "id": "100",
            "diaplayName": "MyValue1"
         }, {
            "id": "200",
            "diaplayName": "MyValue2"
         }
     ]
}

jQuery - Increase the value of a counter when a button is clicked

You are trying to set "++" on a jQuery element!

YOu could declare a js variable

var counter = 0;

and in jQuery code do:

$("#counter").html(counter++);

Javascript reduce on array of objects

You can use reduce method as bellow; If you change the 0(zero) to 1 or other numbers, it will add it to total number. For example, this example gives the total number as 31 however if we change 0 to 1, total number will be 32.

const batteryBatches = [4, 5, 3, 4, 4, 6, 5];

let totalBatteries= batteryBatches.reduce((acc,val) => acc + val ,0)

Preserve Line Breaks From TextArea When Writing To MySQL

Here is what I use

$textToStore = nl2br(htmlentities($inputText, ENT_QUOTES, 'UTF-8'));

$inputText is the text provided by either the form or textarea. $textToStore is the returned text from nl2br and htmlentities, to be stored in your database. ENT_QUOTES will convert both double and single quotes, so you'll have no trouble with those.

How do I make flex box work in safari?

Try this:

select {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -ms-flexbox;
}

how to install gcc on windows 7 machine?

Following up on Mat's answer (use Cygwin), here are some detailed instructions for : installing gcc on Windows The packages you want are gcc, gdb and make. Cygwin installer lets you install additional packages if you need them.

Jenkins Slave port number for firewall

A slave isn't a server, it's a client type application. Network clients (almost) never use a specific port. Instead, they ask the OS for a random free port. This works much better since you usually run clients on many machines where the current configuration isn't known in advance. This prevents thousands of "client wouldn't start because port is already in use" bug reports every day.

You need to tell the security department that the slave isn't a server but a client which connects to the server and you absolutely need to have a rule which says client:ANY -> server:FIXED. The client port number should be >= 1024 (ports 1 to 1023 need special permissions) but I'm not sure if you actually gain anything by adding a rule for this - if an attacker can open privileged ports, they basically already own the machine.

If they argue, then ask them why they don't require the same rule for all the web browsers which people use in your company.

Shuffle DataFrame rows

TL;DR: np.random.shuffle(ndarray) can do the job.
So, in your case

np.random.shuffle(DataFrame.values)

DataFrame, under the hood, uses NumPy ndarray as data holder. (You can check from DataFrame source code)

So if you use np.random.shuffle(), it would shuffles the array along the first axis of a multi-dimensional array. But index of the DataFrame remains unshuffled.

Though, there are some points to consider.

  • function returns none. In case you want to keep a copy of the original object, you have to do so before you pass to the function.
  • sklearn.utils.shuffle(), as user tj89 suggested, can designate random_state along with another option to control output. You may want that for dev purpose.
  • sklearn.utils.shuffle() is faster. But WILL SHUFFLE the axis info(index, column) of the DataFrame along with the ndarray it contains.

Benchmark result

between sklearn.utils.shuffle() and np.random.shuffle().

ndarray

nd = sklearn.utils.shuffle(nd)

0.10793248389381915 sec. 8x faster

np.random.shuffle(nd)

0.8897626010002568 sec

DataFrame

df = sklearn.utils.shuffle(df)

0.3183923360193148 sec. 3x faster

np.random.shuffle(df.values)

0.9357550159329548 sec

Conclusion: If it is okay to axis info(index, column) to be shuffled along with ndarray, use sklearn.utils.shuffle(). Otherwise, use np.random.shuffle()

used code

import timeit
setup = '''
import numpy as np
import pandas as pd
import sklearn
nd = np.random.random((1000, 100))
df = pd.DataFrame(nd)
'''

timeit.timeit('nd = sklearn.utils.shuffle(nd)', setup=setup, number=1000)
timeit.timeit('np.random.shuffle(nd)', setup=setup, number=1000)
timeit.timeit('df = sklearn.utils.shuffle(df)', setup=setup, number=1000)
timeit.timeit('np.random.shuffle(df.values)', setup=setup, number=1000)

How to make a variable accessible outside a function?

Your variable declarations and their scope are correct. The problem you are facing is that the first AJAX request may take a little bit time to finish. Therefore, the second URL will be filled with the value of sID before the its content has been set. You have to remember that AJAX request are normally asynchronous, i.e. the code execution goes on while the data is being fetched in the background.

You have to nest the requests:

$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   obj = name;   // sID is only now available!   sID = obj.id;   console.log(sID); }); 


Clean up your code!

  • Put the second request into a function
  • and let it accept sID as a parameter, so you don't have to declare it globally anymore! (Global variables are almost always evil!)
  • Remove sID and obj variables - name.id is sufficient unless you really need the other variables outside the function.


$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   // We don't need sID or obj here - name.id is sufficient   console.log(name.id);    doSecondRequest(name.id); });  /// TODO Choose a better name function doSecondRequest(sID) {   $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function(stats){         console.log(stats);   }); } 

Hapy New Year :)

How do I set up Eclipse/EGit with GitHub?

In Eclipse, go to Help -> Install New Software -> Add -> Name: any name like egit; Location: http://download.eclipse.org/egit/updates -> Okay. Now Search for egit in Work with and select all the check boxes and press Next till finish.

File -> Import -> search Git and select "Projects from Git" -> Clone URI. In the URI, paste the HTTPS URL of the repository (the one with .git extension). -> Next ->It will show all the branches "Next" -> Local Destination "Next" -> "Import as a general project" -> Next till finish.

You can refer to this Youtube tutorial: https://www.youtube.com/watch?v=ptK9-CNms98

Java 8: Difference between two LocalDateTime in multiple units

Here is a very simple answer to your question. It works.

import java.time.*;
import java.util.*;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;

public class MyClass {
public static void main(String args[]) {
    DateTimeFormatter T = DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm");
    Scanner h = new Scanner(System.in);

    System.out.print("Enter date of birth[dd/mm/yyyy hh:mm]: ");
    String b = h.nextLine();

    LocalDateTime bd = LocalDateTime.parse(b,T);
    LocalDateTime cd = LocalDateTime.now();

    long minutes = ChronoUnit.MINUTES.between(bd, cd);
    long hours = ChronoUnit.HOURS.between(bd, cd);

    System.out.print("Age is: "+hours+ " hours, or " +minutes+ " minutes old");
}
}

Run script with rc.local: script works, but not at boot

I found that because I was using a network-oriented command in my rc.local, sometimes it would fail. I fixed this by putting sleep 3 at the top of my script. I don't know why but it seems when the script is run the network interfaces aren't properly configured or something, and this just allows some time for the DHCP server or something. I don't fully understand but I suppose you could give it a try.

Preview an image before it is uploaded

Default Iamge

                @Html.TextBoxFor(x => x.productModels.DefaultImage, new {@type = "file", @class = "form-control", onchange = "openFile(event)", @name = "DefaultImage", @id = "DefaultImage" })
                @Html.ValidationMessageFor(model => model.productModels.DefaultImage, "", new { @class = "text-danger" })
                    <img src="~/img/ApHandler.png"  style="height:125px; width:125px" id="DefaultImagePreview"/>
            </div>

 <script>
    var openFile = function (event) {
        var input = event.target;

        var reader = new FileReader();
        reader.onload = function () {
            var dataURL = reader.result;
            var output = document.getElementById('DefaultImagePreview');
            output.src = dataURL;
        };
        reader.readAsDataURL(input.files[0]);
    };
</script>

Extracting double-digit months and days from a Python date

you can use a string formatter to pad any integer with zeros. It acts just like C's printf.

>>> d = datetime.date.today()
>>> '%02d' % d.month
'03'

Updated for py36: Use f-strings! For general ints you can use the d formatter and explicitly tell it to pad with zeros:

 >>> d = datetime.date.today()
 >>> f"{d.month:02d}"
 '07'

But datetimes are special and come with special formatters that are already zero padded:

 >>> f"{d:%d}"  # the day
 '01'
 >>> f"{d:%m}"  # the month
 '07'

How to use private Github repo as npm dependency

It can be done via https and oauth or ssh.

https and oauth: create an access token that has "repo" scope and then use this syntax:

"package-name": "git+https://<github_token>:[email protected]/<user>/<repo>.git"

or

ssh: setup ssh and then use this syntax:

"package-name": "git+ssh://[email protected]:<user>/<repo>.git"

(note the use of colon instead of slash before user)

How to Read and Write from the Serial Port

SerialPort (RS-232 Serial COM Port) in C# .NET
This article explains how to use the SerialPort class in .NET to read and write data, determine what serial ports are available on your machine, and how to send files. It even covers the pin assignments on the port itself.

Example Code:

using System;
using System.IO.Ports;
using System.Windows.Forms;

namespace SerialPortExample
{
  class SerialPortProgram
  {
    // Create the serial port with basic settings
    private SerialPort port = new SerialPort("COM1",
      9600, Parity.None, 8, StopBits.One);

    [STAThread]
    static void Main(string[] args)
    { 
      // Instatiate this class
      new SerialPortProgram();
    }

    private SerialPortProgram()
    {
      Console.WriteLine("Incoming Data:");

      // Attach a method to be called when there
      // is data waiting in the port's buffer
      port.DataReceived += new 
        SerialDataReceivedEventHandler(port_DataReceived);

      // Begin communications
      port.Open();

      // Enter an application loop to keep this thread alive
      Application.Run();
    }

    private void port_DataReceived(object sender,
      SerialDataReceivedEventArgs e)
    {
      // Show all the incoming data in the port's buffer
      Console.WriteLine(port.ReadExisting());
    }
  }
}

Git: force user and password prompt

With git config -l, I now see I have a credential.helper=osxkeychain option

That means the credential helper (initially introduced in 1.7.10) is now in effect, and will cache automatically the password for accessing a remote repository over HTTP.
(as in "GIT: Any way to set default login credentials?")

You can disable that option entirely, or only for a single repo.

Why is System.Web.Mvc not listed in Add References?

This has changed for Visual Studio 2012 (I know the original question says VS2010, but the title will still hit on searches).

When you create a VS2012 MVC project, the system.web.mvc is placed in the packages folder which is peer to the solution. This will be referenced in the web project by default and you can find the exact path there).

If you want to reference this in a secondary project (say a supporting .dll with filters or other attributes), then you can reference it from there.

How to export a CSV to Excel using Powershell

Why would you bother? Load your CSV into Excel like this:

$csv = Join-Path $env:TEMP "process.csv"
$xls = Join-Path $env:TEMP "process.xlsx"

$xl = New-Object -COM "Excel.Application"
$xl.Visible = $true

$wb = $xl.Workbooks.OpenText($csv)

$wb.SaveAs($xls, 51)

You just need to make sure that the CSV export uses the delimiter defined in your regional settings. Override with -Delimiter if need be.


Edit: A more general solution that should preserve the values from the CSV as plain text. Code for iterating over the CSV columns taken from here.

$csv = Join-Path $env:TEMP "input.csv"
$xls = Join-Path $env:TEMP "output.xlsx"

$xl = New-Object -COM "Excel.Application"
$xl.Visible = $true

$wb = $xl.Workbooks.Add()
$ws = $wb.Sheets.Item(1)

$ws.Cells.NumberFormat = "@"

$i = 1
Import-Csv $csv | ForEach-Object {
  $j = 1
  foreach ($prop in $_.PSObject.Properties) {
    if ($i -eq 1) {
      $ws.Cells.Item($i, $j++).Value = $prop.Name
    } else {
      $ws.Cells.Item($i, $j++).Value = $prop.Value
    }
  }
  $i++
}

$wb.SaveAs($xls, 51)
$wb.Close()

$xl.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($xl)

Obviously this second approach won't perform too well, because it's processing each cell individually.

How can I enable cURL for an installed Ubuntu LAMP stack?

You only have to install the php5-curl library. You can do this by running

sudo apt-get install php5-curl

Click here for more information.

No module named 'pymysql'

I tried installing pymysql on command prompt by typing

pip install pymysql

But it still dont work on my case, so I decided to try using the terminal IDE and it works.

Rebuild all indexes in a Database

Also a good script, although my laptop ran out of memory, but this was on a very large table

https://basitaalishan.com/2014/02/23/rebuild-all-indexes-on-all-tables-in-the-sql-server-database/

USE [<mydatabasename>]
Go

--/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--Arguments             Data Type               Description
--------------          ------------            ------------
--@FillFactor           [int]                   Specifies a percentage that indicates how full the Database Engine should make the leaf level
--                                              of each index page during index creation or alteration. The valid inputs for this parameter
--                                              must be an integer value from 1 to 100 The default is 0.
--                                              For more information, see http://technet.microsoft.com/en-us/library/ms177459.aspx.

--@PadIndex             [varchar](3)            Specifies index padding. The PAD_INDEX option is useful only when FILLFACTOR is specified,
--                                              because PAD_INDEX uses the percentage specified by FILLFACTOR. If the percentage specified
--                                              for FILLFACTOR is not large enough to allow for one row, the Database Engine internally
--                                              overrides the percentage to allow for the minimum. The number of rows on an intermediate
--                                              index page is never less than two, regardless of how low the value of fillfactor. The valid
--                                              inputs for this parameter are ON or OFF. The default is OFF.
--                                              For more information, see http://technet.microsoft.com/en-us/library/ms188783.aspx.

--@SortInTempDB         [varchar](3)            Specifies whether to store temporary sort results in tempdb. The valid inputs for this
--                                              parameter are ON or OFF. The default is OFF.
--                                              For more information, see http://technet.microsoft.com/en-us/library/ms188281.aspx.

--@OnlineRebuild        [varchar](3)            Specifies whether underlying tables and associated indexes are available for queries and data
--                                              modification during the index operation. The valid inputs for this parameter are ON or OFF.
--                                              The default is OFF.
--                                              Note: Online index operations are only available in Enterprise edition of Microsoft
--                                                      SQL Server 2005 and above.
--                                              For more information, see http://technet.microsoft.com/en-us/library/ms191261.aspx.

--@DataCompression      [varchar](4)            Specifies the data compression option for the specified index, partition number, or range of
--                                              partitions. The options  for this parameter are as follows:
--                                                  > NONE - Index or specified partitions are not compressed.
--                                                  > ROW  - Index or specified partitions are compressed by using row compression.
--                                                  > PAGE - Index or specified partitions are compressed by using page compression.
--                                              The default is NONE.
--                                              Note: Data compression feature is only available in Enterprise edition of Microsoft
--                                                      SQL Server 2005 and above.
--                                              For more information about compression, see http://technet.microsoft.com/en-us/library/cc280449.aspx.

--@MaxDOP               [int]                   Overrides the max degree of parallelism configuration option for the duration of the index
--                                              operation. The valid input for this parameter can be between 0 and 64, but should not exceed
--                                              number of processors available to SQL Server.
--                                              For more information, see http://technet.microsoft.com/en-us/library/ms189094.aspx.
--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

-- Ensure a USE <databasename> statement has been executed first.

SET NOCOUNT ON;

DECLARE  @Version                           [numeric] (18, 10)
        ,@SQLStatementID                    [int]
        ,@CurrentTSQLToExecute              [nvarchar](max)
        ,@FillFactor                        [int]        = 100 -- Change if needed
        ,@PadIndex                          [varchar](3) = N'OFF' -- Change if needed
        ,@SortInTempDB                      [varchar](3) = N'OFF' -- Change if needed
        ,@OnlineRebuild                     [varchar](3) = N'OFF' -- Change if needed
        ,@LOBCompaction                     [varchar](3) = N'ON' -- Change if needed
        ,@DataCompression                   [varchar](4) = N'NONE' -- Change if needed
        ,@MaxDOP                            [int]        = NULL -- Change if needed
        ,@IncludeDataCompressionArgument    [char](1);

IF OBJECT_ID(N'TempDb.dbo.#Work_To_Do') IS NOT NULL
    DROP TABLE #Work_To_Do
CREATE TABLE #Work_To_Do
    (
      [sql_id] [int] IDENTITY(1, 1)
                     PRIMARY KEY ,
      [tsql_text] [varchar](1024) ,
      [completed] [bit]
    )

SET @Version = CAST(LEFT(CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128)), CHARINDEX('.', CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128))) - 1) + N'.' + REPLACE(RIGHT(CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128)), LEN(CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128))) - CHARINDEX('.', CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128)))), N'.', N'') AS [numeric](18, 10))

IF @DataCompression IN (N'PAGE', N'ROW', N'NONE')
    AND (
        @Version >= 10.0
        AND SERVERPROPERTY(N'EngineEdition') = 3
        )
BEGIN
    SET @IncludeDataCompressionArgument = N'Y'
END

IF @IncludeDataCompressionArgument IS NULL
BEGIN
    SET @IncludeDataCompressionArgument = N'N'
END

INSERT INTO #Work_To_Do ([tsql_text], [completed])
SELECT 'ALTER INDEX [' + i.[name] + '] ON' + SPACE(1) + QUOTENAME(t2.[TABLE_CATALOG]) + '.' + QUOTENAME(t2.[TABLE_SCHEMA]) + '.' + QUOTENAME(t2.[TABLE_NAME]) + SPACE(1) + 'REBUILD WITH (' + SPACE(1) + + CASE
        WHEN @PadIndex IS NULL
            THEN 'PAD_INDEX =' + SPACE(1) + CASE i.[is_padded]
                    WHEN 1
                        THEN 'ON'
                    WHEN 0
                        THEN 'OFF'
                    END
        ELSE 'PAD_INDEX =' + SPACE(1) + @PadIndex
        END + CASE
        WHEN @FillFactor IS NULL
            THEN ', FILLFACTOR =' + SPACE(1) + CONVERT([varchar](3), REPLACE(i.[fill_factor], 0, 100))
        ELSE ', FILLFACTOR =' + SPACE(1) + CONVERT([varchar](3), @FillFactor)
        END + CASE
        WHEN @SortInTempDB IS NULL
            THEN ''
        ELSE ', SORT_IN_TEMPDB =' + SPACE(1) + @SortInTempDB
        END + CASE
        WHEN @OnlineRebuild IS NULL
            THEN ''
        ELSE ', ONLINE =' + SPACE(1) + @OnlineRebuild
        END + ', STATISTICS_NORECOMPUTE =' + SPACE(1) + CASE st.[no_recompute]
        WHEN 0
            THEN 'OFF'
        WHEN 1
            THEN 'ON'
        END + ', ALLOW_ROW_LOCKS =' + SPACE(1) + CASE i.[allow_row_locks]
        WHEN 0
            THEN 'OFF'
        WHEN 1
            THEN 'ON'
        END + ', ALLOW_PAGE_LOCKS =' + SPACE(1) + CASE i.[allow_page_locks]
        WHEN 0
            THEN 'OFF'
        WHEN 1
            THEN 'ON'
        END + CASE
        WHEN @IncludeDataCompressionArgument = N'Y'
            THEN CASE
                    WHEN @DataCompression IS NULL
                        THEN ''
                    ELSE ', DATA_COMPRESSION =' + SPACE(1) + @DataCompression
                    END
        ELSE ''
        END + CASE
        WHEN @MaxDop IS NULL
            THEN ''
        ELSE ', MAXDOP =' + SPACE(1) + CONVERT([varchar](2), @MaxDOP)
        END + SPACE(1) + ')'
    ,0
FROM [sys].[tables] t1
INNER JOIN [sys].[indexes] i ON t1.[object_id] = i.[object_id]
    AND i.[index_id] > 0
    AND i.[type] IN (1, 2)
INNER JOIN [INFORMATION_SCHEMA].[TABLES] t2 ON t1.[name] = t2.[TABLE_NAME]
    AND t2.[TABLE_TYPE] = 'BASE TABLE'
INNER JOIN [sys].[stats] AS st WITH (NOLOCK) ON st.[object_id] = t1.[object_id]
    AND st.[name] = i.[name]

SELECT @SQLStatementID = MIN([sql_id])
FROM #Work_To_Do
WHERE [completed] = 0

WHILE @SQLStatementID IS NOT NULL
BEGIN
    SELECT @CurrentTSQLToExecute = [tsql_text]
    FROM #Work_To_Do
    WHERE [sql_id] = @SQLStatementID

    PRINT @CurrentTSQLToExecute

    EXEC [sys].[sp_executesql] @CurrentTSQLToExecute

    UPDATE #Work_To_Do
    SET [completed] = 1
    WHERE [sql_id] = @SQLStatementID

    SELECT @SQLStatementID = MIN([sql_id])
    FROM #Work_To_Do
    WHERE [completed] = 0
END

Failed to load resource 404 (Not Found) - file location error?

Looks like the path you gave doesn't have any bootstrap files in them.

href="~/lib/bootstrap/dist/css/bootstrap.min.css"

Make sure the files exist over there , else point the files to the correct path, which should be in your case

href="~/node_modules/bootstrap/dist/css/bootstrap.min.css"

How to update a value in a json file and save it through node.js

//change the value in the in-memory object
content.val1 = 42;
//Serialize as JSON and Write it to a file
fs.writeFileSync(filename, JSON.stringify(content));

How can I load webpage content into a div on page load?

You can't inject content from another site (domain) using AJAX. The reason an iFrame is suited for these kinds of things is that you can specify the source to be from another domain.

How to use Boost in Visual Studio 2010

What parts of Boost do you need? A lot of stuff is part of TR1 which is shipped with Visual Studio, so you could simply say, for example:

#include <tr1/memory>

using std::tr1::shared_ptr;

According to James, this should also work (in C++0x):

#include <memory>

using std::shared_ptr;

JPQL SELECT between date statement

Try this query (replace t.eventsDate with e.eventsDate):

SELECT e FROM Events e WHERE e.eventsDate BETWEEN :startDate AND :endDate

How do I set default terminal to terminator?

open dconf Editor and go to org > gnome > desktop > application > terminal and change gnome-terminal to terminator

How do negative margins in CSS work and why is (margin-top:-5 != margin-bottom:5)?

Negative margins are valid in css and understanding their (compliant) behaviour is mainly based on the box model and margin collapsing. While certain scenarios are more complex, a lot of common mistakes can be avoided after studying the spec.

For instance, rendering of your sample code is guided by the css spec as described in calculating heights and margins for absolutely positioned non-replaced elements.

If I were to make a graphical representation, I'd probably go with something like this (not to scale):

negative top margin

The margin box lost 8px on the top, however this does not affect the content & padding boxes. Because your element is absolutely positioned, moving the element 8px up does not cause any further disturbance to the layout; with static in-flow content that's not always the case.

Bonus:

Still need convincing that reading specs is the way to go (as opposed to articles like this)? I see you're trying to vertically center the element, so why do you have to set margin-top:-8px; and not margin-top:-50%;?

Well, vertical centering in CSS is harder than it should be. When setting even top or bottom margins in %, the value is calculated as a percentage always relative to the width of the containing block. This is rather a common pitfall and the quirk is rarely described outside of w3 docos

Converting VS2012 Solution to VS2010

Simple solution which worked for me.

  1. Install Vim editor for windows.
  2. Open VS 2012 project solution using Vim editor and modify the version targetting Visual studio solution 10.
  3. Open solution with Visual studio 2010.. and continue with your work ;)

drag drop files into standard html file input

This is what I came out with.

Using Jquery and Html. This will add it to the insert files.

_x000D_
_x000D_
var dropzone = $('#dropzone')_x000D_
_x000D_
_x000D_
dropzone.on('drag dragstart dragend dragover dragenter dragleave drop', function(e) {_x000D_
    e.preventDefault();_x000D_
    e.stopPropagation();_x000D_
  })_x000D_
_x000D_
dropzone.on('dragover dragenter', function() {_x000D_
    $(this).addClass('is-dragover');_x000D_
  })_x000D_
dropzone.on('dragleave dragend drop', function() {_x000D_
    $(this).removeClass('is-dragover');_x000D_
  })  _x000D_
  _x000D_
dropzone.on('drop',function(e) {_x000D_
 var files = e.originalEvent.dataTransfer.files;_x000D_
 // Now select your file upload field _x000D_
 // $('input_field_file').prop('files',files)_x000D_
  });
_x000D_
input { margin: 15px 10px !important;}_x000D_
_x000D_
.dropzone {_x000D_
 padding: 50px;_x000D_
 border: 2px dashed #060;_x000D_
}_x000D_
_x000D_
.dropzone.is-dragover {_x000D_
  background-color: #e6ecef;_x000D_
}_x000D_
_x000D_
.dragover {_x000D_
 bg-color: red;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>_x000D_
<div class="" draggable='true' style='padding: 20px'>_x000D_
 <div id='dropzone' class='dropzone'>_x000D_
  Drop Your File Here_x000D_
 </div>_x000D_
 </div>
_x000D_
_x000D_
_x000D_

How to update only one field using Entity Framework?

I'm late to the game here, but this is how I am doing it, I spent a while hunting for a solution I was satisified with; this produces an UPDATE statement ONLY for the fields that are changed, as you explicitly define what they are through a "white list" concept which is more secure to prevent web form injection anyway.

An excerpt from my ISession data repository:

public bool Update<T>(T item, params string[] changedPropertyNames) where T 
  : class, new()
{
    _context.Set<T>().Attach(item);
    foreach (var propertyName in changedPropertyNames)
    {
        // If we can't find the property, this line wil throw an exception, 
        //which is good as we want to know about it
        _context.Entry(item).Property(propertyName).IsModified = true;
    }
    return true;
}

This could be wrapped in a try..catch if you so wished, but I personally like my caller to know about the exceptions in this scenario.

It would be called in something like this fashion (for me, this was via an ASP.NET Web API):

if (!session.Update(franchiseViewModel.Franchise, new[]
    {
      "Name",
      "StartDate"
  }))
  throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));

How can I extract a predetermined range of lines from a text file on Unix?

perl -ne 'print if 16224..16482' file.txt > new_file.txt

Preloading @font-face fonts?

Since 2017 you have preload

MDN: The preload value of the element's rel attribute allows you to write declarative fetch requests in your HTML , specifying resources that your pages will need very soon after loading, which you therefore want to start preloading early in the lifecycle of a page load, before the browser's main rendering machinery kicks in. This ensures that they are made available earlier and are less likely to block the page's first render, leading to performance improvements.

<link rel="preload" href="/fonts/myfont.eot" as="font" crossorigin="anonymous" />

Always check browser compatibility.

It is most useful for font preloading (not waiting for the browser to find it in some CSS). You can also preload some logos, icons and scripts.

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

You could try using a templating library like Apache Velocity.

http://velocity.apache.org/

Here is an example:

import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.Velocity;

import java.io.StringWriter;

public class TemplateExample {
    public static void main(String args[]) throws Exception {
        Velocity.init();

        VelocityContext context = new VelocityContext();
        context.put("name", "Mark");
        context.put("invoiceNumber", "42123");
        context.put("dueDate", "June 6, 2009");

        String template = "Hello $name. Please find attached invoice" +
                          " $invoiceNumber which is due on $dueDate.";
        StringWriter writer = new StringWriter();
        Velocity.evaluate(context, writer, "TemplateName", template);

        System.out.println(writer);
    }
}

The output would be:

Hello Mark. Please find attached invoice 42123 which is due on June 6, 2009.

How to validate a credit card number

A credit card number is not a bunch of random numbers. There is a formula for checking if it is correct.

After a quick Google search I found this JavaScript which will check a credit card number to be valid.

http://javascript.internet.com/forms/credit-card-number-validation.html

URL Broken: Internet archive: http://web.archive.org/web/20100129174150/http://javascript.internet.com/forms/credit-card-number-validation.html?

<!-- TWO STEPS TO INSTALL CREDIT CARD NUMBER VALIDATION:

  1.  Copy the code into the HEAD of your HTML document
  2.  Add the last code into the BODY of your HTML document  -->

<!-- STEP ONE: Paste this code into the HEAD of your HTML document  -->

<HEAD>

  <script type="text/javascript">
    <!--
    /* This script and many more are available free online at
    The JavaScript Source!! http://javascript.internet.com
    Created by: David Leppek :: https://www.azcode.com/Mod10

    Basically, the algorithm takes each digit, from right to left and muliplies each second
    digit by two. If the multiple is two-digits long (i.e.: 6 * 2 = 12) the two digits of
    the multiple are then added together for a new number (1 + 2 = 3). You then add up the
    string of numbers, both unaltered and new values and get a total sum. This sum is then
    divided by 10 and the remainder should be zero if it is a valid credit card. Hense the
    name Mod 10 or Modulus 10.
    */
    function Mod10(ccNumb) {  // v2.0
      var valid = "0123456789"  // Valid digits in a credit card number
      var len = ccNumb.length;  // The length of the submitted cc number
      var iCCN = parseInt(ccNumb);  // Integer of ccNumb
      var sCCN = ccNumb.toString();  // String of ccNumb
      sCCN = sCCN.replace (/^\s+|\s+$/g,'');  // Strip spaces
      var iTotal = 0;  // Integer total set at zero
      var bNum = true;  // By default assume it is a number
      var bResult = false;  // By default assume it is NOT a valid cc
      var temp;  // Temporary variable for parsing string
      var calc;  // Used for calculation of each digit

      // Determine if the ccNumb is in fact all numbers
      for (var j=0; j<len; j++) {
        temp = "" + sCCN.substring(j, j+1);
        if (valid.indexOf(temp) == "-1"){
          bNum = false;
        }
      }

      // If it is NOT a number, you can either alert to the fact, or just pass a failure
      if (!bNum) {
        /* alert("Not a Number"); */
        bResult = false;
      }

      // Determine if it is the proper length
      if ((len == 0) && (bResult)) {  // Nothing, the field is blank AND passed above # check
        bResult = false;
      }
      else { // ccNumb is a number and the proper length - let's
             //  see if it is a valid card number

        if (len >= 15) {  // 15 or 16 for Amex or V/MC
          for (var i=len;i>0;i--) {  // LOOP through the digits of the card
            calc = parseInt(iCCN) % 10;  // Right most digit
            calc = parseInt(calc);  // Assure it is an integer
            iTotal += calc;  // Running total of the card number as we loop - Do Nothing to first digit
            i--;  // Decrement the count - move to the next digit in the card
            iCCN = iCCN / 10;                               // Subtracts right most digit from ccNumb
            calc = parseInt(iCCN) % 10;     // NEXT right most digit
            calc = calc *2;                                 // multiply the digit by two

            // Instead of some screwy method of converting 16 to a string
            // and then parsing 1 and 6 and then adding them to make 7,
            // I use a simple switch statement to change the value
            // of calc2 to 7 if 16 is the multiple.
            switch(calc) {
              case 10: calc = 1; break;  // 5*2=10 & 1+0 = 1
              case 12: calc = 3; break;  // 6*2=12 & 1+2 = 3
              case 14: calc = 5; break;  // 7*2=14 & 1+4 = 5
              case 16: calc = 7; break;  // 8*2=16 & 1+6 = 7
              case 18: calc = 9; break;  // 9*2=18 & 1+8 = 9
              default: calc = calc;      // 4*2= 8 &   8 = 8  - the same for all lower numbers
            }
            iCCN = iCCN / 10;  // Subtracts right most digit from ccNum
            iTotal += calc;  // Running total of the card number as we loop
          } // END OF LOOP

          if ((iTotal%10)==0){  // Check to see if the sum Mod 10 is zero
            bResult = true;  // This IS (or could be) a valid credit card number.
          }
          else {
            bResult = false;  // This could NOT be a valid credit card number
          }
        }
      }

      // Change alert to on-page display or other indication as needed.
      if (bResult) {
        alert("This IS a valid Credit Card Number!");
      }
      if (!bResult) {
        alert("This is NOT a valid Credit Card Number!");
      }
      return bResult; // Return the results
    }
    // -->
  </script>

</HEAD>


<!-- STEP TWO: Copy this code into the BODY of your HTML document  -->

<BODY>

<div align="center">
  <form name="Form1">
    <table width="50%" border="0" cellspacing="0" cellpadding="5">
      <tr>
        <td width="50%" align="right">Credit Card Number:   </td>
        <td width="50%">
          <input name="CreditCard" type="text" value="4012888888881881" size="18" maxlength="16" style="border: 1px solid #000098; padding: 3px;">
        </td>
      </tr>
      <tr>
        <td colspan="2" align="center">
          <input type="button" name="Button" style="color: #fff; background: #000098; font-weight:bold; border: solid 1px #000;" value="TEST CARD NUMBER" onClick="return Mod10(document.Form1.CreditCard.value);">
        </td>
      </tr>
    </table>
  </form>
</div>

<p><center>
  <font face="arial, helvetica" size"-2">Free JavaScripts provided<br>
  by <a href="http://javascriptsource.com">The JavaScript Source</a></font>
</center><p>

<!-- Script Size:  4.97 KB -->

Null pointer Exception on .setOnClickListener

Try giving your Button in your main.xml a more descriptive name such as:

<Button
                android:id="@+id/buttonXYZ"

(use lowercase in your xml files, at least, the first letter)

And then in your MainActivity class, declare it as:

Button buttonXYZ;

In your onCreate(Bundle savedInstanceState) method, define it as:

buttonXYZ = (Button) findViewById(R.id.buttonXYZ);

Also, move the Buttons/TextViews outside and place them before the .setOnClickListener - it makes the code cleaner.

Username = (EditText)findViewById(R.id.Username);
CompanyID = (EditText)findViewById(R.id.CompanyID);

Pythonic way to check if a file exists?

Instead of os.path.isfile, suggested by others, I suggest using os.path.exists, which checks for anything with that name, not just whether it is a regular file.

Thus:

if not os.path.exists(filename):
    file(filename, 'w').close()

Alternatively:

file(filename, 'w+').close()

The latter will create the file if it exists, but not otherwise. It will, however, fail if the file exists, but you don't have permission to write to it. That's why I prefer the first solution.

What is the difference between Cygwin and MinGW?

Wikipedia Says:

MinGW forked from version 1.3.3 of Cygwin. Although both Cygwin and MinGW can be used to port UNIX software to Windows, they have different approaches: Cygwin aims to provide a complete POSIX layer that provides emulations of several system calls and libraries that exist on Linux, UNIX, and the BSD variants. The POSIX layer runs on top of Windows, sacrificing performance where necessary for compatibility. Accordingly, this approach requires Windows programs written with Cygwin to run on top of a copylefted compatibility library that must be distributed with the program, along with the program's source code. MinGW aims to provide native functionality and performance via direct Windows API calls. Unlike Cygwin, MinGW does not require a compatibility layer DLL and thus programs do not need to be distributed with source code.

Because MinGW is dependent upon Windows API calls, it cannot provide a full POSIX API; it is unable to compile some UNIX applications that can be compiled with Cygwin. Specifically, this applies to applications that require POSIX functionality like fork(), mmap() or ioctl() and those that expect to be run in a POSIX environment. Applications written using a cross-platform library that has itself been ported to MinGW, such as SDL, wxWidgets, Qt, or GTK+, will usually compile as easily in MinGW as they would in Cygwin.

The combination of MinGW and MSYS provides a small, self-contained environment that can be loaded onto removable media without leaving entries in the registry or files on the computer. Cygwin Portable provides a similar feature. By providing more functionality, Cygwin becomes more complicated to install and maintain.

It is also possible to cross-compile Windows applications with MinGW-GCC under POSIX systems. This means that developers do not need a Windows installation with MSYS to compile software that will run on Windows without Cygwin.

Check for special characters (/*-+_@&$#%) in a string?

string s = @"$KUH% I*$)OFNlkfn$";
var withoutSpecial = new string(s.Where(c => Char.IsLetterOrDigit(c) 
                                            || Char.IsWhiteSpace(c)).ToArray());

if (s != withoutSpecial)
{
    Console.WriteLine("String contains special chars");
}

Threads vs Processes in Linux

The decision between thread/process depends a little bit on what you will be using it to. One of the benefits with a process is that it has a PID and can be killed without also terminating the parent.

For a real world example of a web server, apache 1.3 used to only support multiple processes, but in in 2.0 they added an abstraction so that you can swtch between either. Comments seems to agree that processes are more robust but threads can give a little bit better performance (except for windows where performance for processes sucks and you only want to use threads).

How to delete a folder with files using Java

You can try this

public static void deleteDir(File dirFile) {
    if (dirFile.isDirectory()) {
        File[] dirs = dirFile.listFiles();
        for (File dir: dirs) {
            deleteDir(dir);
        }
    }
    dirFile.delete();
}

Normalize columns of pandas data frame

If your data is positively skewed, the best way to normalize is to use the log transformation:

df = np.log10(df)

How do I test if a string is empty in Objective-C?

You have 2 methods to check whether the string is empty or not:

Let's suppose your string name is NSString *strIsEmpty.

Method 1:

if(strIsEmpty.length==0)
{
    //String is empty
}

else
{
    //String is not empty
}

Method 2:

if([strIsEmpty isEqualToString:@""])
{
    //String is empty
}

else
{
    //String is not empty
}

Choose any of the above method and get to know whether string is empty or not.

Sorting object property by values

let toSort = {a:2323, b: 14, c: 799} 
let sorted = Object.entries(toSort ).sort((a,b)=> a[1]-b[1]) 

Output:

[ [ "b", 14 ], [ "c", 799 ], [ "a", 2323 ] ]

Java: random long number in 0 <= x < n range

//use system time as seed value to get a good random number

   Random random = new Random(System.currentTimeMillis());
              long x;
             do{
                x=random.nextLong();
             }while(x<0 && x > n); 

//Loop until get a number greater or equal to 0 and smaller than n

How to change Hash values?

Since ruby 2.4.0 you can use native Hash#transform_values method:

hash = {"a" => "b", "c" => "d"}
new_hash = hash.transform_values(&:upcase)
# => {"a" => "B", "c" => "D"}

There is also destructive Hash#transform_values! version.

How to set focus on an input field after rendering?

You don't need getInputDOMNode?? in this case...

Just simply get the ref and focus() it when component gets mounted -- componentDidMount...

import React from 'react';
import { render } from 'react-dom';

class myApp extends React.Component {

  componentDidMount() {
    this.nameInput.focus();
  }

  render() {
    return(
      <div>
        <input ref={input => { this.nameInput = input; }} />
      </div>
    );
  }

}

ReactDOM.render(<myApp />, document.getElementById('root'));

Add days Oracle SQL

You can use the plus operator to add days to a date.

order_date + 20

How to select from subquery using Laravel Query Builder?

In addition to @delmadord's answer and your comments:

Currently there is no method to create subquery in FROM clause, so you need to manually use raw statement, then, if necessary, you will merge all the bindings:

$sub = Abc::where(..)->groupBy(..); // Eloquent Builder instance

$count = DB::table( DB::raw("({$sub->toSql()}) as sub") )
    ->mergeBindings($sub->getQuery()) // you need to get underlying Query Builder
    ->count();

Mind that you need to merge bindings in correct order. If you have other bound clauses, you must put them after mergeBindings:

$count = DB::table( DB::raw("({$sub->toSql()}) as sub") )

    // ->where(..) wrong

    ->mergeBindings($sub->getQuery()) // you need to get underlying Query Builder

    // ->where(..) correct

    ->count();

Get variable from PHP to JavaScript

It depends on what type of PHP variable you want to use in Javascript. For example, entire PHP objects with class methods cannot be used in Javascript. You can, however, use the built-in PHP JSON (JavaScript Object Notation) functions to convert simple PHP variables into JSON representations. For more information, please read the following links:

You can generate the JSON representation of your PHP variable and then print it into your Javascript code when the page loads. For example:

<script type="text/javascript">
  var foo = <?php echo json_encode($bar); ?>;
</script>

How do I escape a string inside JavaScript code inside an onClick handler?

First, it would be simpler if the onclick handler was set this way:

<a id="someLinkId"href="#">Select</a>
<script type="text/javascript">
  document.getElementById("someLinkId").onClick = 
   function() {
      SelectSurveyItem('<%itemid%>', '<%itemname%>'); return false;
    };

</script>

Then itemid and itemname need to be escaped for JavaScript (that is, " becomes \", etc.).

If you are using Java on the server side, you might take a look at the class StringEscapeUtils from jakarta's common-lang. Otherwise, it should not take too long to write your own 'escapeJavascript' method.

LINQ .Any VS .Exists - What's the difference?

The difference is that Any is an extension method for any IEnumerable<T> defined on System.Linq.Enumerable. It can be used on any IEnumerable<T> instance.

Exists does not appear to be an extension method. My guess is that coll is of type List<T>. If so Exists is an instance method which functions very similar to Any.

In short, the methods are essentially the same. One is more general than the other.

  • Any also has an overload which takes no parameters and simply looks for any item in the enumerable.
  • Exists has no such overload.

SQL Group By with an Order By

In Oracle, something like this works nicely to separate your counting and ordering a little better. I'm not sure if it will work in MySql 4.

select 'Tag', counts.cnt
from
  (
  select count(*) as cnt, 'Tag'
  from 'images-tags'
  group by 'tag'
  ) counts
order by counts.cnt desc

What is a smart pointer and when should I use one?

Here is the Link for similar answers : http://sickprogrammersarea.blogspot.in/2014/03/technical-interview-questions-on-c_6.html

A smart pointer is an object that acts, looks and feels like a normal pointer but offers more functionality. In C++, smart pointers are implemented as template classes that encapsulate a pointer and override standard pointer operators. They have a number of advantages over regular pointers. They are guaranteed to be initialized as either null pointers or pointers to a heap object. Indirection through a null pointer is checked. No delete is ever necessary. Objects are automatically freed when the last pointer to them has gone away. One significant problem with these smart pointers is that unlike regular pointers, they don't respect inheritance. Smart pointers are unattractive for polymorphic code. Given below is an example for the implementation of smart pointers.

Example:

template <class X>
class smart_pointer
{
          public:
               smart_pointer();                          // makes a null pointer
               smart_pointer(const X& x)            // makes pointer to copy of x

               X& operator *( );
               const X& operator*( ) const;
               X* operator->() const;

               smart_pointer(const smart_pointer <X> &);
               const smart_pointer <X> & operator =(const smart_pointer<X>&);
               ~smart_pointer();
          private:
               //...
};

This class implement a smart pointer to an object of type X. The object itself is located on the heap. Here is how to use it:

smart_pointer <employee> p= employee("Harris",1333);

Like other overloaded operators, p will behave like a regular pointer,

cout<<*p;
p->raise_salary(0.5);

Convert System.Drawing.Color to RGB and Hex Value

You could keep it simple and use the native color translator:

Color red = ColorTranslator.FromHtml("#FF0000");
string redHex = ColorTranslator.ToHtml(red);

Then break the three color pairs into integer form:

int value = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);

Invalid attempt to read when no data is present

I used the code below and it worked for me.

String email="";
    SqlDataReader reader=cmd.ExecuteReader();
    if(reader.Read()){
        email=reader["Email"].ToString();
    }

String To=email;

What's better at freeing memory with PHP: unset() or $var = null

It was mentioned in the unset manual's page in 2009:

unset() does just what its name says - unset a variable. It does not force immediate memory freeing. PHP's garbage collector will do it when it see fits - by intention as soon, as those CPU cycles aren't needed anyway, or as late as before the script would run out of memory, whatever occurs first.

If you are doing $whatever = null; then you are rewriting variable's data. You might get memory freed / shrunk faster, but it may steal CPU cycles from the code that truly needs them sooner, resulting in a longer overall execution time.

(Since 2013, that unset man page don't include that section anymore)

Note that until php5.3, if you have two objects in circular reference, such as in a parent-child relationship, calling unset() on the parent object will not free the memory used for the parent reference in the child object. (Nor will the memory be freed when the parent object is garbage-collected.) (bug 33595)


The question "difference between unset and = null" details some differences:


unset($a) also removes $a from the symbol table; for example:

$a = str_repeat('hello world ', 100);
unset($a);
var_dump($a);

Outputs:

Notice: Undefined variable: a in xxx
NULL

But when $a = null is used:

$a = str_repeat('hello world ', 100);
$a = null;
var_dump($a);

Outputs:

NULL

It seems that $a = null is a bit faster than its unset() counterpart: updating a symbol table entry appears to be faster than removing it.


  • when you try to use a non-existent (unset) variable, an error will be triggered and the value for the variable expression will be null. (Because, what else should PHP do? Every expression needs to result in some value.)
  • A variable with null assigned to it is still a perfectly normal variable though.

SQL Server : fetching records between two dates?

Your question didnt ask how to use BETWEEN correctly, rather asked for help with the unexpectedly truncated results...

As mentioned/hinting at in the other answers, the problem is that you have time segments in addition to the dates.

In my experience, using date diff is worth the extra wear/tear on the keyboard. It allows you to express exactly what you want, and you are covered.

select * 
from xxx 
where datediff(d, '2012-10-26', dates) >=0
and  datediff(d, dates,'2012-10-27') >=0

using datediff, if the first date is before the second date, you get a positive number. There are several ways to write the above, for instance always having the field first, then the constant. Just flipping the operator. Its a matter of personal preference.

you can be explicit about whether you want to be inclusive or exclusive of the endpoints by dropping one or both equal signs.

BETWEEN will work in your case, because the endpoints are both assumed to be midnight (ie DATEs). If your endpoints were also DATETIME, using BETWEEN may require even more casting. In my mind DATEDIFF was put in our lives to insulate us from those issues.

Get path of executable

char exePath[512];
CString strexePath;
GetModuleFileName(NULL,exePath,512);
strexePath.Format("%s",exePath);
strexePath = strexePath.Mid(0,strexePath.ReverseFind('\\'));

Named capturing groups in JavaScript regex?

As Tim Pietzcker said ECMAScript 2018 introduces named capturing groups into JavaScript regexes. But what I did not find in the above answers was how to use the named captured group in the regex itself.

you can use named captured group with this syntax: \k<name>. for example

var regexObj = /(?<year>\d{4})-(?<day>\d{2})-(?<month>\d{2}) year is \k<year>/

and as Forivin said you can use captured group in object result as follow:

let result = regexObj.exec('2019-28-06 year is 2019');
// result.groups.year === '2019';
// result.groups.month === '06';
// result.groups.day === '28';

_x000D_
_x000D_
  var regexObj = /(?<year>\d{4})-(?<day>\d{2})-(?<month>\d{2}) year is \k<year>/mgi;_x000D_
_x000D_
function check(){_x000D_
    var inp = document.getElementById("tinput").value;_x000D_
    let result = regexObj.exec(inp);_x000D_
    document.getElementById("year").innerHTML = result.groups.year;_x000D_
    document.getElementById("month").innerHTML = result.groups.month;_x000D_
    document.getElementById("day").innerHTML = result.groups.day;_x000D_
}
_x000D_
td, th{_x000D_
  border: solid 2px #ccc;_x000D_
}
_x000D_
<input id="tinput" type="text" value="2019-28-06 year is 2019"/>_x000D_
<br/>_x000D_
<br/>_x000D_
<span>Pattern: "(?<year>\d{4})-(?<day>\d{2})-(?<month>\d{2}) year is \k<year>";_x000D_
<br/>_x000D_
<br/>_x000D_
<button onclick="check()">Check!</button>_x000D_
<br/>_x000D_
<br/>_x000D_
<table>_x000D_
  <thead>_x000D_
    <tr>_x000D_
      <th>_x000D_
        <span>Year</span>_x000D_
      </th>_x000D_
      <th>_x000D_
        <span>Month</span>_x000D_
      </th>_x000D_
      <th>_x000D_
        <span>Day</span>_x000D_
      </th>_x000D_
    </tr>_x000D_
  </thead>_x000D_
  <tbody>_x000D_
    <tr>_x000D_
      <td>_x000D_
        <span id="year"></span>_x000D_
      </td>_x000D_
      <td>_x000D_
        <span id="month"></span>_x000D_
      </td>_x000D_
      <td>_x000D_
        <span id="day"></span>_x000D_
      </td>_x000D_
    </tr>_x000D_
  </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Boxplot show the value of mean

You can use the output value from stat_summary()

ggplot(data=PlantGrowth, aes(x=group, y=weight, fill=group)) 
+ geom_boxplot() 
+ stat_summary(fun.y=mean, colour="darkred", geom="point", hape=18, size=3,show_guide = FALSE)
+ stat_summary(fun.y=mean, colour="red", geom="text", show_guide = FALSE, 
               vjust=-0.7, aes( label=round(..y.., digits=1)))

From ND to 1D arrays

I wanted to see a benchmark result of functions mentioned in answers including unutbu's.

Also want to point out that numpy doc recommend to use arr.reshape(-1) in case view is preferable. (even though ravel is tad faster in the following result)


TL;DR: np.ravel is the most performant (by very small amount).

Benchmark

Functions:

numpy version: '1.18.0'

Execution times on different ndarray sizes

+-------------+----------+-----------+-----------+-------------+
|  function   |   10x10  |  100x100  | 1000x1000 | 10000x10000 |
+-------------+----------+-----------+-----------+-------------+
| ravel       | 0.002073 |  0.002123 |  0.002153 |    0.002077 |
| reshape(-1) | 0.002612 |  0.002635 |  0.002674 |    0.002701 |
| flatten     | 0.000810 |  0.007467 |  0.587538 |  107.321913 |
| flat        | 0.000337 |  0.000255 |  0.000227 |    0.000216 |
+-------------+----------+-----------+-----------+-------------+

Conclusion

ravel and reshape(-1)'s execution time was consistent and independent from ndarray size. However, ravel is tad faster, but reshape provides flexibility in reshaping size. (maybe that's why numpy doc recommend to use it instead. Or there could be some cases where reshape returns view and ravel doesn't).
If you are dealing with large size ndarray, using flatten can cause a performance issue. Recommend not to use it. Unless you need a copy of the data to do something else.

Used code

import timeit
setup = '''
import numpy as np
nd = np.random.randint(10, size=(10, 10))
'''

timeit.timeit('nd = np.reshape(nd, -1)', setup=setup, number=1000)
timeit.timeit('nd = np.ravel(nd)', setup=setup, number=1000)
timeit.timeit('nd = nd.flatten()', setup=setup, number=1000)
timeit.timeit('nd.flat', setup=setup, number=1000)

jQuery: go to URL with target="_blank"

If you want to create the popup window through jQuery then you'll need to use a plugin. This one seems like it will do what you want:

http://rip747.github.com/popupwindow/

Alternately, you can always use JavaScript's window.open function.

Note that with either approach, the new window must be opened in response to user input/action (so for instance, a click on a link or button). Otherwise the browser's popup blocker will just block the popup.

How to compile .c file with OpenSSL includes?

Your include paths indicate that you should be compiling against the system's OpenSSL installation. You shouldn't have the .h files in your package directory - it should be picking them up from /usr/include/openssl.

The plain OpenSSL package (libssl) doesn't include the .h files - you need to install the development package as well. This is named libssl-dev on Debian, Ubuntu and similar distributions, and libssl-devel on CentOS, Fedora, Red Hat and similar.

Angular 2 Scroll to bottom (Chat style)

Sharing my solution, because I was not completely satisfied with the rest. My problem with AfterViewChecked is that sometimes I'm scrolling up, and for some reason, this life hook gets called and it scrolls me down even if there were no new messages. I tried using OnChanges but this was an issue, which lead me to this solution. Unfortunately, using only DoCheck, it was scrolling down before the messages were rendered, which was not useful either, so I combined them so that DoCheck is basically indicating AfterViewChecked if it should call scrollToBottom.

Happy to receive feedback.

export class ChatComponent implements DoCheck, AfterViewChecked {

    @Input() public messages: Message[] = [];
    @ViewChild('scrollable') private scrollable: ElementRef;

    private shouldScrollDown: boolean;
    private iterableDiffer;

    constructor(private iterableDiffers: IterableDiffers) {
        this.iterableDiffer = this.iterableDiffers.find([]).create(null);
    }

    ngDoCheck(): void {
        if (this.iterableDiffer.diff(this.messages)) {
            this.numberOfMessagesChanged = true;
        }
    }

    ngAfterViewChecked(): void {
        const isScrolledDown = Math.abs(this.scrollable.nativeElement.scrollHeight - this.scrollable.nativeElement.scrollTop - this.scrollable.nativeElement.clientHeight) <= 3.0;

        if (this.numberOfMessagesChanged && !isScrolledDown) {
            this.scrollToBottom();
            this.numberOfMessagesChanged = false;
        }
    }

    scrollToBottom() {
        try {
            this.scrollable.nativeElement.scrollTop = this.scrollable.nativeElement.scrollHeight;
        } catch (e) {
            console.error(e);
        }
    }

}

chat.component.html

<div class="chat-wrapper">

    <div class="chat-messages-holder" #scrollable>

        <app-chat-message *ngFor="let message of messages" [message]="message">
        </app-chat-message>

    </div>

    <div class="chat-input-holder">
        <app-chat-input (send)="onSend($event)"></app-chat-input>
    </div>

</div>

chat.component.sass

.chat-wrapper
  display: flex
  justify-content: center
  align-items: center
  flex-direction: column
  height: 100%

  .chat-messages-holder
    overflow-y: scroll !important
    overflow-x: hidden
    width: 100%
    height: 100%

String concatenation in MySQL

Try:

select concat(first_name,last_name) as "Name" from test.student

or, better:

select concat(first_name," ",last_name) as "Name" from test.student

What are the differences between a superkey and a candidate key?

Basically, a Candidate Key is a Super Key from which no more Attribute can be pruned.

A Super Key identifies uniquely rows/tuples in a table/relation of a database. It is composed by a set of attributes that combined can assume values unique over the rows/tuples of a table/relation. A Candidate Key is built by a Super Key, iteratively removing/pruning non-key attributes, keeping an invariant: the newly created Key still need to uniquely identifies the rows/tuples.

A Candidate Key might be seen as a minimal Super Key, in terms of attributes.

Candidate Keys can be used to reference uniquely rows/tuples but from the RDBMS engine perspective the burden to maintain indexes on them is far heavier.

mongoError: Topology was destroyed

I was struggling with this for some time - As you can see from other answers, the issue can be very different.

The easiest way to find out whats causing is this is to turn on loggerLevel: 'info' in the options

Change output format for MySQL command line results to CSV

It is how to save results to CSV on the client-side without additional non-standard tools. This example uses only mysql client and awk.

One-line:

mysql --skip-column-names --batch -e 'select * from dump3' t | awk -F'\t' '{ sep=""; for(i = 1; i <= NF; i++) { gsub(/\\t/,"\t",$i); gsub(/\\n/,"\n",$i); gsub(/\\\\/,"\\",$i); gsub(/"/,"\"\"",$i); printf sep"\""$i"\""; sep=","; if(i==NF){printf"\n"}}}'

Logical explanation of what is needed to do

  1. First, let see how data looks like in RAW mode (with --raw option). the database and table are respectively t and dump3

    You can see the field starting from "new line" (in the first row) is splitted into three lines due to new lines placed in the value.

mysql --skip-column-names --batch --raw -e 'select * from dump3' t

one line        2       new line
quotation marks " backslash \ two quotation marks "" two backslashes \\ two tabs                new line
the end of field

another line    1       another line description without any special chars
  1. OUTPUT data in batch mode (without --raw option) - each record changed to the one-line texts by escaping characters like \ <tab> and new-lines
mysql --skip-column-names --batch -e 'select * from dump3' t

one line      2  new line\nquotation marks " backslash \\ two quotation marks "" two backslashes \\\\ two tabs\t\tnew line\nthe end of field
another line  1  another line description without any special chars
  1. And data output in CSV format

The clue is to save data in CSV format with escaped characters.

The way to do that is to convert special entities which mysql --batch produces (\t as tabs \\ as backshlash and \n as newline) into equivalent bytes for each value (field). Then whole value is escaped by " and enclosed also by ". Btw - using the same characters for escaping and enclosing gently simplifies output and processing, because you don't have two special characters. For this reason all you have to do with values (from csv format perspective) is to change " to "" whithin values. In more common way (with escaping and enclosing respectively \ and ") you would have to first change \ to \\ and then change " into \".

And the commands' explanation step by step:

# we produce one-line output as showed in step 2.
mysql --skip-column-names --batch -e 'select * from dump3' t

# set fields separator to  because mysql produces in that way
| awk -F'\t' 

# this start iterating every line/record from the mysql data - standard behaviour of awk
'{ 

# field separator is empty because we don't print a separator before the first output field
sep=""; 

-- iterating by every field and converting the field to csv proper value
for(i = 1; i <= NF; i++) { 
-- note: \\ two shlashes below mean \ for awk because they're escaped

-- changing \t into byte corresponding to <tab> 
    gsub(/\\t/, "\t",$i); 

-- changing \n into byte corresponding to new line
    gsub(/\\n/, "\n",$i); 

-- changing two \\ into one \  
    gsub(/\\\\/,"\\",$i);

-- changing value into CSV proper one literally - change " into ""
    gsub(/"/,   "\"\"",$i); 

-- print output field enclosed by " and adding separator before
    printf sep"\""$i"\"";  

-- separator is set after first field is processed - because earlier we don't need it
    sep=","; 

-- adding new line after the last field processed - so this indicates csv record separator
    if(i==NF) {printf"\n"} 
    }
}'

How to refresh a page with jQuery by passing a parameter to URL

I'm using Jquery Load to handels this, works great for me. check out my code from my project. I need to refresh with arguments to put Javascript variable into php

if (isset($_GET['language'])){
    $language = $_GET['language'];
}else{
    echo '<script>';    
    echo '  var userLang = navigator.language || navigator.userLanguage;';
    echo '  if(userLang.search("zh") != -1) {';
    echo '      var language = "chn";';
    echo '  }else{';
    echo '      var language = "eng";';
    echo '  }';
    echo '$("html").load("index.php","language=" + language);';
    echo '</script>';
    die;
}

git: diff between file in local repo and origin

If [remote-path] and [local-path] are the same, you can do

$ git fetch origin master
$ git diff origin/master -- [local-path]

Note 1: The second command above will compare against the locally stored remote tracking branch. The fetch command is required to update the remote tracking branch to be in sync with the contents of the remote server. Alternatively, you can just do

$ git diff master:<path-or-file-name>

Note 2: master can be replaced in the above examples with any branch name

Replace and overwrite instead of appending

file='path/test.xml' 
with open(file, 'w') as filetowrite:
    filetowrite.write('new content')

Open the file in 'w' mode, you will be able to replace its current text save the file with new contents.