Programs & Examples On #Script tag

The

How to tell if a <script> tag failed to load

The script from Erwinus works great, but isn't very clearly coded. I took the liberty to clean it up and decipher what it was doing. I've made these changes:

  • Meaningful variable names
  • Use of prototype.
  • require() uses an argument variable
  • No alert() messages are returned by default
  • Fixed some syntax errors and scope issues I was getting

Thanks again to Erwinus, the functionality itself is spot on.

function ScriptLoader() {
}

ScriptLoader.prototype = {

    timer: function (times, // number of times to try
                     delay, // delay per try
                     delayMore, // extra delay per try (additional to delay)
                     test, // called each try, timer stops if this returns true
                     failure, // called on failure
                     result // used internally, shouldn't be passed
            ) {
        var me = this;
        if (times == -1 || times > 0) {
            setTimeout(function () {
                result = (test()) ? 1 : 0;
                me.timer((result) ? 0 : (times > 0) ? --times : times, delay + ((delayMore) ? delayMore : 0), delayMore, test, failure, result);
            }, (result || delay < 0) ? 0.1 : delay);
        } else if (typeof failure == 'function') {
            setTimeout(failure, 1);
        }
    },

    addEvent: function (el, eventName, eventFunc) {
        if (typeof el != 'object') {
            return false;
        }

        if (el.addEventListener) {
            el.addEventListener(eventName, eventFunc, false);
            return true;
        }

        if (el.attachEvent) {
            el.attachEvent("on" + eventName, eventFunc);
            return true;
        }

        return false;
    },

    // add script to dom
    require: function (url, args) {
        var me = this;
        args = args || {};

        var scriptTag = document.createElement('script');
        var headTag = document.getElementsByTagName('head')[0];
        if (!headTag) {
            return false;
        }

        setTimeout(function () {
            var f = (typeof args.success == 'function') ? args.success : function () {
            };
            args.failure = (typeof args.failure == 'function') ? args.failure : function () {
            };
            var fail = function () {
                if (!scriptTag.__es) {
                    scriptTag.__es = true;
                    scriptTag.id = 'failed';
                    args.failure(scriptTag);
                }
            };
            scriptTag.onload = function () {
                scriptTag.id = 'loaded';
                f(scriptTag);
            };
            scriptTag.type = 'text/javascript';
            scriptTag.async = (typeof args.async == 'boolean') ? args.async : false;
            scriptTag.charset = 'utf-8';
            me.__es = false;
            me.addEvent(scriptTag, 'error', fail); // when supported
            // when error event is not supported fall back to timer
            me.timer(15, 1000, 0, function () {
                return (scriptTag.id == 'loaded');
            }, function () {
                if (scriptTag.id != 'loaded') {
                    fail();
                }
            });
            scriptTag.src = url;
            setTimeout(function () {
                try {
                    headTag.appendChild(scriptTag);
                } catch (e) {
                    fail();
                }
            }, 1);
        }, (typeof args.delay == 'number') ? args.delay : 1);
        return true;
    }
};

$(document).ready(function () {
    var loader = new ScriptLoader();
    loader.require('resources/templates.js', {
        async: true, success: function () {
            alert('loaded');
        }, failure: function () {
            alert('NOT loaded');
        }
    });
});

HTML/Javascript: how to access JSON data loaded in a script tag with src set

While it's not currently possible with the script tag, it is possible with an iframe if it's from the same domain.

<iframe
id="mySpecialId"
src="/my/link/to/some.json"
onload="(()=>{if(!window.jsonData){window.jsonData={}}try{window.jsonData[this.id]=JSON.parse(this.contentWindow.document.body.textContent.trim())}catch(e){console.warn(e)}this.remove();})();"
onerror="((err)=>console.warn(err))();"
style="display: none;"
></iframe>

To use the above, simply replace the id and src attribute with what you need. The id (which we'll assume in this situation is equal to mySpecialId) will be used to store the data in window.jsonData["mySpecialId"].

In other words, for every iframe that has an id and uses the onload script will have that data synchronously loaded into the window.jsonData object under the id specified.

I did this for fun and to show that it's "possible' but I do not recommend that it be used.


Here is an alternative that uses a callback instead.

<script>
    function someCallback(data){
        /** do something with data */
        console.log(data);

    }
    function jsonOnLoad(callback){
        const raw = this.contentWindow.document.body.textContent.trim();
        try {
          const data = JSON.parse(raw);
          /** do something with data */
          callback(data);
        }catch(e){
          console.warn(e.message);
        }
        this.remove();
    }
</script>
<!-- I frame with src pointing to json file on server, onload we apply "this" to have the iframe context, display none as we don't want to show the iframe -->
<iframe src="your/link/to/some.json" onload="jsonOnLoad.apply(this, someCallback)" style="display: none;"></iframe>

Tested in chrome and should work in firefox. Unsure about IE or Safari.

How to force a script reload and re-execute?

Use this function to find all script elements containing some word and refresh them.

_x000D_
_x000D_
function forceReloadJS(srcUrlContains) {_x000D_
  $.each($('script:empty[src*="' + srcUrlContains + '"]'), function(index, el) {_x000D_
    var oldSrc = $(el).attr('src');_x000D_
    var t = +new Date();_x000D_
    var newSrc = oldSrc + '?' + t;_x000D_
_x000D_
    console.log(oldSrc, ' to ', newSrc);_x000D_
_x000D_
    $(el).remove();_x000D_
    $('<script/>').attr('src', newSrc).appendTo('head');_x000D_
  });_x000D_
}_x000D_
_x000D_
forceReloadJS('/libs/');
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
_x000D_
_x000D_
_x000D_

How to dynamically insert a <script> tag via jQuery after page load?

Here's the correct way to do it with modern (2014) JQuery:

$(function () {
  $('<script>')
    .attr('type', 'text/javascript')
    .text('some script here')
    .appendTo('head');
})

or if you really want to replace a div you could do:

$(function () {
  $('<script>')
    .attr('type', 'text/javascript')
    .text('some script here')
    .replaceAll('#someelement');
});

How to pass parameters to a Script tag?

Another way is to use meta tags. Whatever data is supposed to be passed to your JavaScript can be assigned like this:

<meta name="yourdata" content="whatever" />
<meta name="moredata" content="more of this" />

The data can then be pulled from the meta tags like this (best done in a DOMContentLoaded event handler):

var data1 = document.getElementsByName('yourdata')[0].content;
var data2 = document.getElementsByName('moredata')[0].content;

Absolutely no hassle with jQuery or the likes, no hacks and workarounds necessary, and works with any HTML version that supports meta tags...

Getting path relative to the current working directory?

If you don't mind the slashes being switched, you could [ab]use Uri:

Uri file = new Uri(@"c:\foo\bar\blop\blap.txt");
// Must end in a slash to indicate folder
Uri folder = new Uri(@"c:\foo\bar\");
string relativePath = 
Uri.UnescapeDataString(
    folder.MakeRelativeUri(file)
        .ToString()
        .Replace('/', Path.DirectorySeparatorChar)
    );

As a function/method:

string GetRelativePath(string filespec, string folder)
{
    Uri pathUri = new Uri(filespec);
    // Folders must end in a slash
    if (!folder.EndsWith(Path.DirectorySeparatorChar.ToString()))
    {
        folder += Path.DirectorySeparatorChar;
    }
    Uri folderUri = new Uri(folder);
    return Uri.UnescapeDataString(folderUri.MakeRelativeUri(pathUri).ToString().Replace('/', Path.DirectorySeparatorChar));
}

How many characters in varchar(max)

From http://msdn.microsoft.com/en-us/library/ms176089.aspx

varchar [ ( n | max ) ] Variable-length, non-Unicode character data. n can be a value from 1 through 8,000. max indicates that the maximum storage size is 2^31-1 bytes. The storage size is the actual length of data entered + 2 bytes. The data entered can be 0 characters in length. The ISO synonyms for varchar are char varying or character varying.

1 character = 1 byte. And don't forget 2 bytes for the termination. So, 2^31-3 characters.

fetch gives an empty response body

This requires changes to the frontend JS and the headers sent from the backend.

Frontend

Remove "mode":"no-cors" in the fetch options.

fetch(
  "http://example.com/api/docs", 
  {
    // mode: "no-cors",
    method: "GET"
  }
)
  .then(response => response.text())
  .then(data => console.log(data))

Backend

When your server responds to the request, include the CORS headers specifying the origin from where the request is coming. If you don't care about the origin, specify the * wildcard.

The raw response should include a header like this.

Access-Control-Allow-Origin: *

Removing "http://" from a string

preg_replace('/^[^:\/?]+:\/\//','',$url); 

some results:

input: http://php.net/preg_replace output: php.net/preg_replace  input: https://www.php.net/preg_replace output: www.php.net/preg_replace  input: ftp://www.php.net/preg_replace output: www.php.net/preg_replace  input: https://php.net/preg_replace?url=http://whatever.com output: php.net/preg_replace?url=http://whatever.com  input: php.net/preg_replace?url=http://whatever.com output: php.net/preg_replace?url=http://whatever.com  input: php.net?site=http://whatever.com output: php.net?site=http://whatever.com 

Const in JavaScript: when to use it and is it necessary?

I am not an expert in the JS compiling business, but it makes sense to say, that v8 makes use from the const flag

Normally a after declaring and changing a bunch of variables, the memory gets fragmented, and v8 is stopping to execute, makes a pause some time of a few seconds, to make gc, or garbage collection.

if a variable is declared with const v8 can be confident to put it in a tight fixed size container between other const variables, since it will never change. It can also save the proper operations for that datatypes since the type will not change.

Spring boot - Not a managed type

In my case the problem was due to my forgetting to have annotated my Entity classes with @javax.persistence.Entity annotation. Doh!

//The class reported as "not a amanaged type"
@javax.persistence.Entity
public class MyEntityClass extends my.base.EntityClass {
    ....
}

Check if Cell value exists in Column, and then get the value of the NEXT Cell

How about this?

=IF(ISERROR(MATCH(A1,B:B, 0)), "No Match", INDIRECT(ADDRESS(MATCH(A1,B:B, 0), 3)))

The "3" at the end means for column C.

How can I pass selected row to commandLink inside dataTable or ui:repeat?

As to the cause, the <f:attribute> is specific to the component itself (populated during view build time), not to the iterated row (populated during view render time).

There are several ways to achieve the requirement.

  1. If your servletcontainer supports a minimum of Servlet 3.0 / EL 2.2, then just pass it as an argument of action/listener method of UICommand component or AjaxBehavior tag. E.g.

     <h:commandLink action="#{bean.insert(item.id)}" value="insert" />
    

    In combination with:

     public void insert(Long id) {
         // ...
     }
    

    This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.

    You can even pass the entire item object:

     <h:commandLink action="#{bean.insert(item)}" value="insert" />
    

    with:

     public void insert(Item item) {
         // ...
     }
    

    On Servlet 2.5 containers, this is also possible if you supply an EL implementation which supports this, like as JBoss EL. For configuration detail, see this answer.


  2. Use <f:param> in UICommand component. It adds a request parameter.

     <h:commandLink action="#{bean.insert}" value="insert">
         <f:param name="id" value="#{item.id}" />
     </h:commandLink>
    

    If your bean is request scoped, let JSF set it by @ManagedProperty

     @ManagedProperty(value="#{param.id}")
     private Long id; // +setter
    

    Or if your bean has a broader scope or if you want more fine grained validation/conversion, use <f:viewParam> on the target view, see also f:viewParam vs @ManagedProperty:

     <f:viewParam name="id" value="#{bean.id}" required="true" />
    

    Either way, this has the advantage that the datamodel doesn't necessarily need to be preserved for the form submit (for the case that your bean is request scoped).


  3. Use <f:setPropertyActionListener> in UICommand component. The advantage is that this removes the need for accessing the request parameter map when the bean has a broader scope than the request scope.

     <h:commandLink action="#{bean.insert}" value="insert">
         <f:setPropertyActionListener target="#{bean.id}" value="#{item.id}" />
     </h:commandLink>
    

    In combination with

     private Long id; // +setter
    

    It'll be just available by property id in action method. This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.


  4. Bind the datatable value to DataModel<E> instead which in turn wraps the items.

     <h:dataTable value="#{bean.model}" var="item">
    

    with

     private transient DataModel<Item> model;
    
     public DataModel<Item> getModel() {
         if (model == null) {
             model = new ListDataModel<Item>(items);
         }
         return model;
     }
    

    (making it transient and lazily instantiating it in the getter is mandatory when you're using this on a view or session scoped bean since DataModel doesn't implement Serializable)

    Then you'll be able to access the current row by DataModel#getRowData() without passing anything around (JSF determines the row based on the request parameter name of the clicked command link/button).

     public void insert() {
         Item item = model.getRowData();
         Long id = item.getId();
         // ...
     }
    

    This also requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.


  5. Use Application#evaluateExpressionGet() to programmatically evaluate the current #{item}.

     public void insert() {
         FacesContext context = FacesContext.getCurrentInstance();
         Item item = context.getApplication().evaluateExpressionGet(context, "#{item}", Item.class);
         Long id = item.getId();
         // ...
     }
    

Which way to choose depends on the functional requirements and whether the one or the other offers more advantages for other purposes. I personally would go ahead with #1 or, when you'd like to support servlet 2.5 containers as well, with #2.

Regular expression for letters, numbers and - _

[A-Za-z0-9_.-]*

This will also match for empty strings, if you do not want that exchange the last * for an +

What is the proof of of (N–1) + (N–2) + (N–3) + ... + 1= N*(N–1)/2

Start with the triangle...

    *
   **
  ***
 ****

representing 1+2+3+4 so far. Cut the triangle in half along one dimension...

     *
    **
  * **
 ** **

Rotate the smaller part 180 degrees, and stick it on top of the bigger part...

    **
    * 

     *
    **
    **
    **

Close the gap to get a rectangle.

At first sight this only works if the base of the rectangle has an even length - but if it has an odd length, you just cut the middle column in half - it still works with a half-unit-wide twice-as-tall (still integer area) strip on one side of your rectangle.

Whatever the base of the triangle, the width of your rectangle is (base / 2) and the height is (base + 1), giving ((base + 1) * base) / 2.

However, my base is your n-1, since the bubble sort compares a pair of items at a time, and therefore iterates over only (n-1) positions for the first loop.

display html page with node.js

This did the trick for me:

var express = require('express'),
app = express(); 
app.use('/', express.static(__dirname + '/'));
app.listen(8080);

How do you split and unsplit a window/view in Eclipse IDE?

This is possible with the menu items Window>Editor>Toggle Split Editor.

Current shortcut for splitting is:

Azerty keyboard:

  • Ctrl + _ for split horizontally, and
  • Ctrl + { for split vertically.

Qwerty US keyboard:

  • Ctrl + Shift + - (accessing _) for split horizontally, and
  • Ctrl + Shift + [ (accessing {) for split vertically.

MacOS - Qwerty US keyboard:

  • + Shift + - (accessing _) for split horizontally, and
  • + Shift + [ (accessing {) for split vertically.

On any other keyboard if a required key is unavailable (like { on a german Qwertz keyboard), the following generic approach may work:

  • Alt + ASCII code + Ctrl then release Alt

Example: ASCII for '{' = 123, so press 'Alt', '1', '2', '3', 'Ctrl' and release 'Alt', effectively typing '{' while 'Ctrl' is pressed, to split vertically.

Example of vertical split:

https://bugs.eclipse.org/bugs/attachment.cgi?id=238285

PS:

  • The menu items Window>Editor>Toggle Split Editor were added with Eclipse Luna 4.4 M4, as mentioned by Lars Vogel in "Split editor implemented in Eclipse M4 Luna"
  • The split editor is one of the oldest and most upvoted Eclipse bug! Bug 8009
  • The split editor functionality has been developed in Bug 378298, and will be available as of Eclipse Luna M4. The Note & Newsworthy of Eclipse Luna M4 will contain the announcement.

what is trailing whitespace and how can I handle this?

This is just a warning and it doesn't make problem for your project to run, you can just ignore it and continue coding. But if you're obsessed about clean coding, same as me, you have two options:

  1. Hover the mouse on warning in VS Code or any IDE and use quick fix to remove white spaces.
  2. Press f1 then type trim trailing whitespace.

What are metaclasses in Python?

Python 3 update

There are (at this point) two key methods in a metaclass:

  • __prepare__, and
  • __new__

__prepare__ lets you supply a custom mapping (such as an OrderedDict) to be used as the namespace while the class is being created. You must return an instance of whatever namespace you choose. If you don't implement __prepare__ a normal dict is used.

__new__ is responsible for the actual creation/modification of the final class.

A bare-bones, do-nothing-extra metaclass would like:

class Meta(type):

    def __prepare__(metaclass, cls, bases):
        return dict()

    def __new__(metacls, cls, bases, clsdict):
        return super().__new__(metacls, cls, bases, clsdict)

A simple example:

Say you want some simple validation code to run on your attributes -- like it must always be an int or a str. Without a metaclass, your class would look something like:

class Person:
    weight = ValidateType('weight', int)
    age = ValidateType('age', int)
    name = ValidateType('name', str)

As you can see, you have to repeat the name of the attribute twice. This makes typos possible along with irritating bugs.

A simple metaclass can address that problem:

class Person(metaclass=Validator):
    weight = ValidateType(int)
    age = ValidateType(int)
    name = ValidateType(str)

This is what the metaclass would look like (not using __prepare__ since it is not needed):

class Validator(type):
    def __new__(metacls, cls, bases, clsdict):
        # search clsdict looking for ValidateType descriptors
        for name, attr in clsdict.items():
            if isinstance(attr, ValidateType):
                attr.name = name
                attr.attr = '_' + name
        # create final class and return it
        return super().__new__(metacls, cls, bases, clsdict)

A sample run of:

p = Person()
p.weight = 9
print(p.weight)
p.weight = '9'

produces:

9
Traceback (most recent call last):
  File "simple_meta.py", line 36, in <module>
    p.weight = '9'
  File "simple_meta.py", line 24, in __set__
    (self.name, self.type, value))
TypeError: weight must be of type(s) <class 'int'> (got '9')

Note: This example is simple enough it could have also been accomplished with a class decorator, but presumably an actual metaclass would be doing much more.

The 'ValidateType' class for reference:

class ValidateType:
    def __init__(self, type):
        self.name = None  # will be set by metaclass
        self.attr = None  # will be set by metaclass
        self.type = type
    def __get__(self, inst, cls):
        if inst is None:
            return self
        else:
            return inst.__dict__[self.attr]
    def __set__(self, inst, value):
        if not isinstance(value, self.type):
            raise TypeError('%s must be of type(s) %s (got %r)' %
                    (self.name, self.type, value))
        else:
            inst.__dict__[self.attr] = value

How to maximize a plt.show() window using Python

Here is a function based on @Pythonio's answer. I encapsulate it into a function that automatically detects which backend is it using and do the corresponding actions.

def plt_set_fullscreen():
    backend = str(plt.get_backend())
    mgr = plt.get_current_fig_manager()
    if backend == 'TkAgg':
        if os.name == 'nt':
            mgr.window.state('zoomed')
        else:
            mgr.resize(*mgr.window.maxsize())
    elif backend == 'wxAgg':
        mgr.frame.Maximize(True)
    elif backend == 'Qt4Agg':
        mgr.window.showMaximized()

How to pre-populate the sms body text via an html link

Neither Android nor iPhones currently support the body copy element in a Tap to SMS hyperlink. It can be done programmatically though,

MFMessageComposeViewController *picker = [[MFMessageComposeViewController alloc] init];
picker.messageComposeDelegate = self;

picker.recipients = [NSArray arrayWithObject:@"48151623"];  
picker.body = @"Body text.";

[self presentModalViewController:picker animated:YES];
[picker release];

Kill all processes for a given user

Just (temporarily) killed my Macbook with

killall -u pu -m .

where pu is my userid. Watch the dot at the end of the command.

Also try

pkill -u pu

or

ps -o pid -u pu | xargs kill -1

How to get current page URL in MVC 3

public static string GetCurrentWebsiteRoot()
{
    return HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Authority);
}

Get top 1 row of each group

It is checked in SQLite that you can use the following simple query with GROUP BY

SELECT MAX(DateCreated), *
FROM DocumentStatusLogs
GROUP BY DocumentID

Here MAX help to get the maximum DateCreated FROM each group.

But it seems that MYSQL doesn't associate *-columns with the value of max DateCreated :(

How to remove all subviews of a view in Swift?

For iOS/Swift, to get rid of all subviews I use:

for v in view.subviews{
   v.removeFromSuperview()
}

to get rid of all subviews of a particular class (like UILabel) I use:

for v in view.subviews{
   if v is UILabel{
      v.removeFromSuperview()
   }
}

Facebook database design?

Have a look at the following database schema, reverse engineered by Anatoly Lubarsky:

Facebook Schema

XML Carriage return encoding

xml:space="preserve" has to work for all compliant XML parsers.

However, note that in HTML the line break is just whitespace and NOT a line break (this is represented with the <br /> (X)HTML tag, maybe this is the problem which you are facing.

You can also add &#10; and/or &#13; to insert CR/LF characters.

Does WGET timeout?

According to the man page of wget, there are a couple of options related to timeouts -- and there is a default read timeout of 900s -- so I say that, yes, it could timeout.


Here are the options in question :

-T seconds
--timeout=seconds

Set the network timeout to seconds seconds. This is equivalent to specifying --dns-timeout, --connect-timeout, and --read-timeout, all at the same time.


And for those three options :

--dns-timeout=seconds

Set the DNS lookup timeout to seconds seconds.
DNS lookups that don't complete within the specified time will fail.
By default, there is no timeout on DNS lookups, other than that implemented by system libraries.

--connect-timeout=seconds

Set the connect timeout to seconds seconds.
TCP connections that take longer to establish will be aborted.
By default, there is no connect timeout, other than that implemented by system libraries.

--read-timeout=seconds

Set the read (and write) timeout to seconds seconds.
The "time" of this timeout refers to idle time: if, at any point in the download, no data is received for more than the specified number of seconds, reading fails and the download is restarted.
This option does not directly affect the duration of the entire download.


I suppose using something like

wget -O - -q -t 1 --timeout=600 http://www.example.com/cron/run

should make sure there is no timeout before longer than the duration of your script.

(Yeah, that's probably the most brutal solution possible ^^ )

Error during installing HAXM, VT-X not working

If your emulators were working and now they aren't due to Avast...

Avast no longer has the option for "Enable Hardware-assisted Virtualization" in Troubleshooting. (it's now March 2017)

Avast captures "emulator.exe", which disables emulators,and stows it in the Virus chest. Open the chest, "Restore and add to exclusions" and your emulator works again...

Pictorial on Avast fix

C# Double - ToString() formatting with two decimal places but no rounding

Following can be used for display only which uses the property of String ..

double value = 123.456789;
String.Format("{0:0.00}", value);

How do I set the rounded corner radius of a color drawable using xml?

Try below code

<shape xmlns:android="http://schemas.android.com/apk/res/android">
<corners
    android:bottomLeftRadius="30dp"
    android:bottomRightRadius="30dp"
    android:topLeftRadius="30dp"
    android:topRightRadius="30dp" />
<solid android:color="#1271BB" />

<stroke
    android:width="5dp"
    android:color="#1271BB" />

<padding
    android:bottom="1dp"
    android:left="1dp"
    android:right="1dp"
    android:top="1dp" /></shape>

Creating a generic method in C#

What if you specified the default value to return, instead of using default(T)?

public static T GetQueryString<T>(string key, T defaultValue) {...}

It makes calling it easier too:

var intValue = GetQueryString("intParm", Int32.MinValue);
var strValue = GetQueryString("strParm", "");
var dtmValue = GetQueryString("dtmPatm", DateTime.Now); // eg use today's date if not specified

The downside being you need magic values to denote invalid/missing querystring values.

CSS: 100% width or height while keeping aspect ratio?

Had the same issue. The problem for me was that the height property was also already defined elsewhere, fixed it like this:

.img{
    max-width: 100%;
    max-height: 100%;
    height: inherit !important;
}

jQuery - replace all instances of a character in a string

RegEx is the way to go in most cases.

In some cases, it may be faster to specify more elements or the specific element to perform the replace on:

$(document).ready(function () {
    $('.myclass').each(function () {
        $('img').each(function () {
            $(this).attr('src', $(this).attr('src').replace('_s.jpg', '_n.jpg'));
        })
    })
});

This does the replace once on each string, but it does it using a more specific selector.

How to perform keystroke inside powershell?

function Do-SendKeys {
    param (
        $SENDKEYS,
        $WINDOWTITLE
    )
    $wshell = New-Object -ComObject wscript.shell;
    IF ($WINDOWTITLE) {$wshell.AppActivate($WINDOWTITLE)}
    Sleep 1
    IF ($SENDKEYS) {$wshell.SendKeys($SENDKEYS)}
}
Do-SendKeys -WINDOWTITLE Print -SENDKEYS '{TAB}{TAB}'
Do-SendKeys -WINDOWTITLE Print
Do-SendKeys -SENDKEYS '%{f4}'

More Pythonic Way to Run a Process X Times

The for loop is definitely more pythonic, as it uses Python's higher level built in functionality to convey what you're doing both more clearly and concisely. The overhead of range vs xrange, and assigning an unused i variable, stem from the absence of a statement like Verilog's repeat statement. The main reason to stick to the for range solution is that other ways are more complex. For instance:

from itertools import repeat

for unused in repeat(None, 10):
    del unused   # redundant and inefficient, the name is clear enough
    print "This is run 10 times"

Using repeat instead of range here is less clear because it's not as well known a function, and more complex because you need to import it. The main style guides if you need a reference are PEP 20 - The Zen of Python and PEP 8 - Style Guide for Python Code.

We also note that the for range version is an explicit example used in both the language reference and tutorial, although in that case the value is used. It does mean the form is bound to be more familiar than the while expansion of a C-style for loop.

ActionBarActivity cannot resolve a symbol

If the same error occurs in ADT/Eclipse

Add Action Bar Sherlock library in your project.

Now, to remove the "import The import android.support.v7 cannot be resolved" error download a jar file named as android-support-v7-appcompat.jar and add it in your project lib folder.

This will surely removes your both errors.

AWS - Disconnected : No supported authentication methods available (server sent :publickey)

For me, I just had to tell FileZilla where the private keys were:

  1. Select Edit > Settings from the main menu
  2. In the Settings dialog box, go to Connection > SFTP
  3. Click the "Add key file..." button
  4. Navigate to and then select the desired PEM file(s)

How to compare two java objects

You need to implement the equals() method in your MyClass.

The reason that == didn't work is this is checking that they refer to the same instance. Since you did new for each, each one is a different instance.

The reason that equals() didn't work is because you didn't implement it yourself yet. I believe it's default behavior is the same thing as ==.

Note that you should also implement hashcode() if you're going to implement equals() because a lot of java.util Collections expect that.

Where does one get the "sys/socket.h" header/source file?

Since you've labeled the question C++, you might be interested in using boost::asio, ACE, or some other cross-platform socket library for C++ or for C. Some other cross-platform libraries may be found in the answers to C++ sockets library for cross-platform and Cross platform Networking API.

Assuming that using a third party cross-platform sockets library is not an option for you...

The header <sys/socket.h> is defined in IEEE Std. 1003.1 (POSIX), but sadly Windows is non-compliant with the POSIX standard. The MinGW compiler is a port of GCC for compiling Windows applications, and therefore does not include these POSIX system headers. If you install GCC using Cygwin, then it will include these system headers to emulate a POSIX environment on Windows. Be aware, however, that if you use Cygwin for sockets that a.) you will need to put the cygwin DLL in a place where your application can read it and b.) Cygwin headers and Windows headers don't interact very well (so if you plan on including windows.h, then you probably don't want to be including sys/socket.h).

My personal recommendation would be to download a copy of VirtualBox, download a copy of Ubuntu, install Ubuntu into VirtualBox, and then do your coding and testing on Ubuntu. Alternatively, I am told that Microsoft sells a "UNIX subsystem" and that it is pre-installed on certain higher-end editions of Windows, although I have no idea how compliant this system is (and, if it is compliant, with which edition of the UNIX standard it is compliant). Winsockets are also an option, although they can behave in subtly different ways than their POSIX counterparts, even though the signatures may be similar.

Make virtualenv inherit specific packages from your global site-packages

You can use the --system-site-packages and then "overinstall" the specific stuff for your virtualenv. That way, everything you install into your virtualenv will be taken from there, otherwise it will be taken from your system.

Prevent text selection after double click

FWIW, I set user-select: none to the parent element of those child elements that I don't want somehow selected when double clicking anywhere on the parent element. And it works! Cool thing is contenteditable="true", text selection and etc. still works on the child elements!

So like:

<div style="user-select: none">
  <p>haha</p>
  <p>haha</p>
  <p>haha</p>
  <p>haha</p>
</div>

How to run C program on Mac OS X using Terminal?

On Mac gcc is installed by default in /usr/local/bin

To run C:

gcc -o tutor tutor.c 

Java Equivalent of C# async/await?

Java itself has no equivalent features, but third-party libraries exist which offer similar functionality, e.g.Kilim.

Difference between session affinity and sticky session?

Sticky session means to route the requests of particular session to the same physical machine who served the first request for that session.

Load a UIView from nib in Swift

My contribution:

extension UIView {
    class func fromNib<T: UIView>() -> T {
        return Bundle(for: T.self).loadNibNamed(String(describing: T.self), owner: nil, options: nil)![0] as! T
    }
}

Then call it like this:

let myCustomView: CustomView = UIView.fromNib()

..or even:

let myCustomView: CustomView = .fromNib()

Which sort algorithm works best on mostly sorted data?

Splaysort is an obscure sorting method based on splay trees, a type of adaptive binary tree. Splaysort is good not only for partially sorted data, but also partially reverse-sorted data, or indeed any data that has any kind of pre-existing order. It is O(nlogn) in the general case, and O(n) in the case where the data is sorted in some way (forward, reverse, organ-pipe, etc.).

Its great advantage over insertion sort is that it doesn't revert to O(n^2) behaviour when the data isn't sorted at all, so you don't need to be absolutely sure that the data is partially sorted before using it.

Its disadvantage is the extra space overhead of the splay tree structure it needs, as well as the time required to build and destroy the splay tree. But depending on the size of data and amount of pre-sortedness that you expect, the overhead may be worth it for the increase in speed.

A paper on splaysort was published in Software--Practice & Experience.

jQuery animate margin top

use 'marginTop' instead of MarginTop

$(this).find('.info').animate({ 'marginTop': '-50px', opacity: 0.5 }, 1000);

SHA512 vs. Blowfish and Bcrypt

I would recommend Ulrich Drepper's SHA-256/SHA-512 based crypt implementation.

We ported these algorithms to Java, and you can find a freely licensed version of them at ftp://ftp.arlut.utexas.edu/java_hashes/.

Note that most modern (L)Unices support Drepper's algorithm in their /etc/shadow files.

Which is faster: multiple single INSERTs or one multiple-row INSERT?

A major factor will be whether you're using a transactional engine and whether you have autocommit on.

Autocommit is on by default and you probably want to leave it on; therefore, each insert that you do does its own transaction. This means that if you do one insert per row, you're going to be committing a transaction for each row.

Assuming a single thread, that means that the server needs to sync some data to disc for EVERY ROW. It needs to wait for the data to reach a persistent storage location (hopefully the battery-backed ram in your RAID controller). This is inherently rather slow and will probably become the limiting factor in these cases.

I'm of course assuming that you're using a transactional engine (usually innodb) AND that you haven't tweaked the settings to reduce durability.

I'm also assuming that you're using a single thread to do these inserts. Using multiple threads muddies things a bit because some versions of MySQL have working group-commit in innodb - this means that multiple threads doing their own commits can share a single write to the transaction log, which is good because it means fewer syncs to persistent storage.

On the other hand, the upshot is, that you REALLY WANT TO USE multi-row inserts.

There is a limit over which it gets counter-productive, but in most cases it's at least 10,000 rows. So if you batch them up to 1,000 rows, you're probably safe.

If you're using MyISAM, there's a whole other load of things, but I'll not bore you with those. Peace.

what is the basic difference between stack and queue?

STACK is a LIFO (last in, first out) list. means suppose 3 elements are inserted in stack i.e 10,20,30. 10 is inserted first & 30 is inserted last so 30 is first deleted from stack & 10 is last deleted from stack.this is an LIFO list(Last In First Out).

QUEUE is FIFO list(First In First Out).means one element is inserted first which is to be deleted first.e.g queue of peoples.

Formatting numbers (decimal places, thousands separators, etc) with CSS

Probably the best way to do so is combo of setting a span with a class denoting your formatting then use Jquery .each to do formatting on the spans when the DOM is loaded...

What does "javascript:void(0)" mean?

It's worth mentioning that you'll sometimes see void 0 when checking for undefined, simply because it requires fewer characters.

For example:

if (something === undefined) {
    doSomething();
}

Compared to:

if (something === void 0) {
    doSomething();
}

Some minification methods replace undefined with void 0 for this reason.

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

Apple provides a macro to help provide better code compatibility, including Swift. Using the macro looks like this.

typedef NS_ENUM(NSInteger, PlayerStateType) {
  PlayerStateOff,
  PlayerStatePlaying,
  PlayerStatePaused
};

Documented here

Are iframes considered 'bad practice'?

The original frameset model (Frameset and Frame-elements) were very bad from a usability standpoint. IFrame vas a later invention which didn't have as many problems as the original frameset model, but it does have its drawback.

If you allow the user to navigate inside the IFrame, then links and bookmarks will not work as expected (because you bookmark the URL of the outer page, but not the URL of the iframe).

How to convert a date to milliseconds

You don't have a Date, you have a String representation of a date. You should convert the String into a Date and then obtain the milliseconds. To convert a String into a Date and vice versa you should use SimpleDateFormat class.

Here's an example of what you want/need to do (assuming time zone is not involved here):

String myDate = "2014/10/29 18:10:45";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = sdf.parse(myDate);
long millis = date.getTime();

Still, be careful because in Java the milliseconds obtained are the milliseconds between the desired epoch and 1970-01-01 00:00:00.


Using the new Date/Time API available since Java 8:

String myDate = "2014/10/29 18:10:45";
LocalDateTime localDateTime = LocalDateTime.parse(myDate,
    DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss") );
/*
  With this new Date/Time API, when using a date, you need to
  specify the Zone where the date/time will be used. For your case,
  seems that you want/need to use the default zone of your system.
  Check which zone you need to use for specific behaviour e.g.
  CET or America/Lima
*/
long millis = localDateTime
    .atZone(ZoneId.systemDefault())
    .toInstant().toEpochMilli();

ERROR 2003 (HY000): Can't connect to MySQL server (111)

I had the same problem trying to connect to a remote mysql db.

I fixed it by opening the firewall on the db server to allow traffic through:

sudo ufw allow mysql

Ruby, remove last N characters from a string?

if you are using rails, try:

"my_string".last(2) # => "ng"

[EDITED]

To get the string WITHOUT the last 2 chars:

n = "my_string".size
"my_string"[0..n-3] # => "my_stri"

Note: the last string char is at n-1. So, to remove the last 2, we use n-3.

How do you debug PHP scripts?

Komodo IDE works well with xdebug, even for the remore debugging. It needs minimum amount of configuration. All you need is a version of php that Komodo can use locally to step through the code on a breakpoint. If you have the script imported into komodo project, then you can set breakpoints with a mouse-click just how you would set it inside eclipse for debugging a java program. Remote debugging is obviously more tricky to get it to work correctly ( you might have to map the remote url with a php script in your workspace ) than a local debugging setup which is pretty easy to configure if you are on a MAC or a linux desktop.

Reading Email using Pop3 in C#

I've successfully used OpenPop.NET to access emails via POP3.

Android requires compiler compliance level 5.0 or 6.0. Found '1.7' instead. Please use Android Tools > Fix Project Properties

Doing Project -> Clean... fixed it for me.

My eclipse had stopped working so I cleaned workspace directory and after I run eclipse when I import the project I had this problem. Other solutions suggested here didn't work.

Shortcuts in Objective-C to concatenate NSStrings

You can use NSArray as

NSString *string1=@"This"

NSString *string2=@"is just"

NSString *string3=@"a test"  

NSArray *myStrings = [[NSArray alloc] initWithObjects:string1, string2, string3,nil];

NSString *fullLengthString = [myStrings componentsJoinedByString:@" "];

or

you can use

NSString *imageFullName=[NSString stringWithFormat:@"%@ %@ %@.", string1,string2,string3];

Convert form data to JavaScript object with jQuery

[UPDATE 2020]

With a simple oneliner in vanilla js that leverages fromEntries (as always, check browser support):

Object.fromEntries(new FormData(form))

Simple dynamic breadcrumb

use parse_url and then output the result in a loop:

$urlinfo = parse_url($the_url);
echo makelink($urlinfo['hostname']);
foreach($breadcrumb in $urlinfo['path']) {
  echo makelink($breadcrumb);
}

function makelink($str) {
  return '<a href="'.urlencode($str).'" title="'.htmlspecialchars($str).'">'.htmlspecialchars($str).'</a>';
}

(pseudocode)

How can I download a file from a URL and save it in Rails?

Check out Net::HTTP in the standard library. The documentation provides several examples on how to download documents using HTTP.

Determine the size of an InputStream

you can get the size of InputStream using getBytes(inputStream) of Utils.java check this following link

Get Bytes from Inputstream

How can I start and check my MySQL log?

Enable general query log by the following query in mysql command line

SET GLOBAL general_log = 'ON';

Now open C:/xampp/mysql/data/mysql.log and check query log

If it fails, open your my.cnf file. For windows its my.ini file and enable it there. Just make sure its in the [mysqld] section

[mysqld]
general_log             = 1

Note: In xampp my.ini file can be either found in xampp\mysql or in c:\windows directory

Form inline inside a form horizontal in twitter bootstrap?

to make it simple, just add a class="form-inline" before the input.

example:

<div class="col-md-4 form-inline"> //add the class here...
     <label>Lot Size:</label>
     <input type="text" value="" name="" class="form-control" >
 </div>

How to succinctly write a formula with many variables from a data frame?

An extension of juba's method is to use reformulate, a function which is explicitly designed for such a task.

## Create a formula for a model with a large number of variables:
xnam <- paste("x", 1:25, sep="")

reformulate(xnam, "y")
y ~ x1 + x2 + x3 + x4 + x5 + x6 + x7 + x8 + x9 + x10 + x11 + 
    x12 + x13 + x14 + x15 + x16 + x17 + x18 + x19 + x20 + x21 + 
    x22 + x23 + x24 + x25

For the example in the OP, the easiest solution here would be

# add y variable to data.frame d
d <- cbind(y, d)
reformulate(names(d)[-1], names(d[1]))
y ~ x1 + x2 + x3

or

mod <- lm(reformulate(names(d)[-1], names(d[1])), data=d)

Note that adding the dependent variable to the data.frame in d <- cbind(y, d) is preferred not only because it allows for the use of reformulate, but also because it allows for future use of the lm object in functions like predict.

Jquery resizing image

Modifying Aleksandar's answer to make it as jquery plugin and accepts maxwidth and maxheight as arguments, suggested by Nathan.

$.fn.resize = function(maxWidth,maxHeight) {
return this.each(function() {
    var ratio = 0;
    var width = $(this).width();
    var height = $(this).height();
    if(width > maxWidth){
        ratio = maxWidth / width;
        $(this).css("width", maxWidth);
        $(this).css("height", height * ratio);
        height = height * ratio;
    }
    var width = $(this).width();
    var height = $(this).height();
    if(height > maxHeight){
        ratio = maxHeight / height;
        $(this).css("height", maxHeight);
        $(this).css("width", width * ratio);
        width = width * ratio;
    }
});
};

Used as $('.imgClass').resize(300,50);

Smooth scrolling with just pure css

You can do this with pure CSS but you will need to hard code the offset scroll amounts, which may not be ideal should you be changing page content- or should dimensions of your content change on say window resize.

You're likely best placed to use e.g. jQuery, specifically:

$('html, body').stop().animate({
   scrollTop: element.offset().top
}, 1000);

A complete implementation may be:

$('#up, #down').on('click', function(e){
    e.preventDefault();
    var target= $(this).get(0).id == 'up' ? $('#down') : $('#up');
    $('html, body').stop().animate({
       scrollTop: target.offset().top
    }, 1000);
});

Where element is the target element to scroll to and 1000 is the delay in ms before completion.

Demo Fiddle

The benefit being, no matter what changes to your content dimensions, the function will not need to be altered.

How to count lines in a document?

If all you want is the number of lines (and not the number of lines and the stupid file name coming back):

wc -l < /filepath/filename.ext

As previously mentioned these also work (but are inferior for other reasons):

awk 'END{print NR}' file       # not on all unixes
sed -n '$=' file               # (GNU sed) also not on all unixes
grep -c ".*" file              # overkill and probably also slower

Uncaught TypeError: Cannot read property 'msie' of undefined

$.browser was removed from jQuery starting with version 1.9. It is now available as a plugin. It's generally recommended to avoid browser detection, which is why it was removed.

How to get height of Keyboard?

Swift

You can get the keyboard height by subscribing to the UIKeyboardWillShowNotification notification. (Assuming you want to know what the height will be before it's shown).

Swift 4

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: UIResponder.keyboardWillShowNotification,
    object: nil
)
@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}

Swift 3

NotificationCenter.default.addObserver(
    self,
    selector: #selector(keyboardWillShow),
    name: NSNotification.Name.UIKeyboardWillShow,
    object: nil
)
@objc func keyboardWillShow(_ notification: Notification) {
    if let keyboardFrame: NSValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
        let keyboardRectangle = keyboardFrame.cgRectValue
        let keyboardHeight = keyboardRectangle.height
    }
}

Swift 2

NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
func keyboardWillShow(notification: NSNotification) {
        let userInfo: NSDictionary = notification.userInfo!
        let keyboardFrame: NSValue = userInfo.valueForKey(UIKeyboardFrameEndUserInfoKey) as! NSValue
        let keyboardRectangle = keyboardFrame.CGRectValue()
        let keyboardHeight = keyboardRectangle.height
    }

Convert a String of Hex into ASCII in Java

Easiest way to do it with javax.xml.bind.DatatypeConverter:

    String hex = "75546f7272656e745c436f6d706c657465645c6e667375635f6f73745f62795f6d757374616e675c50656e64756c756d2d392c303030204d696c65732e6d7033006d7033006d7033004472756d202620426173730050656e64756c756d00496e2053696c69636f00496e2053696c69636f2a3b2a0050656e64756c756d0050656e64756c756d496e2053696c69636f303038004472756d2026204261737350656e64756c756d496e2053696c69636f30303800392c303030204d696c6573203c4d757374616e673e50656e64756c756d496e2053696c69636f3030380050656e64756c756d50656e64756c756d496e2053696c69636f303038004d50330000";
    byte[] s = DatatypeConverter.parseHexBinary(hex);
    System.out.println(new String(s));

Insert a line break in mailto body

<a href="mailto:[email protected]?subject=Request&body=Hi,%0DName:[your name] %0DGood day " target="_blank"></a>

Try adding %0D to break the line. This will definitely work.

Above code will display the following:

Hi,
Name:[your name] 
Good day

How to use ImageBackground to set background image for screen in react-native

To add background Image, React Native is based on component, the ImageBackground Component requires two props style={{}} and source={require('')}

 <ImageBackground source={require('./wallpaper.jpg')} style={{width: '100%', height: '100%'}}> 
<....yourContent Goes here...>
    </ImageBackground>

Enum ToString with user friendly strings

I do this with extension methods:

public enum ErrorLevel
{
  None,
  Low,
  High,
  SoylentGreen
}

public static class ErrorLevelExtensions
{
  public static string ToFriendlyString(this ErrorLevel me)
  {
    switch(me)
    {
      case ErrorLevel.None:
        return "Everything is OK";
      case ErrorLevel.Low:
        return "SNAFU, if you know what I mean.";
      case ErrorLevel.High:
        return "Reaching TARFU levels";
      case ErrorLevel.SoylentGreen:
        return "ITS PEOPLE!!!!";
      default:
        return "Get your damn dirty hands off me you FILTHY APE!";
    }
  }
}

Jquery - How to make $.post() use contentType=application/json?

I know this is a late answer, I actually have a shortcut method that I use for posting/reading to/from MS based services.. it works with MVC as well as ASMX etc...

Use:

$.msajax(
  '/services/someservice.asmx/SomeMethod'
  ,{}  /*empty object for nothing, or object to send as Application/JSON */
  ,function(data,jqXHR) {
    //use the data from the response.
  }
  ,function(err,jqXHR) {
    //additional error handling.
  }
);
//sends a json request to an ASMX or WCF service configured to reply to JSON requests.
(function ($) {
  var tries = 0; //IE9 seems to error out the first ajax call sometimes... will retry up to 5 times

  $.msajax = function (url, data, onSuccess, onError) {
    return $.ajax({
      'type': "POST"
      , 'url': url
      , 'contentType': "application/json"
      , 'dataType': "json"
      , 'data': typeof data == "string" ? data : JSON.stringify(data || {})
      ,beforeSend: function(jqXHR) {
        jqXHR.setRequestHeader("X-MicrosoftAjax","Delta=true");
      }
      , 'complete': function(jqXHR, textStatus) {
        handleResponse(jqXHR, textStatus, onSuccess, onError, function(){
          setTimeout(function(){
            $.msajax(url, data, onSuccess, onError);
          }, 100 * tries); //try again
        });
      }
    });
  }

  $.msajax.defaultErrorMessage = "Error retreiving data.";


  function logError(err, errorHandler, jqXHR) {
    tries = 0; //reset counter - handling error response

    //normalize error message
    if (typeof err == "string") err = { 'Message': err };

    if (console && console.debug && console.dir) {
      console.debug("ERROR processing jQuery.msajax request.");
      console.dir({ 'details': { 'error': err, 'jqXHR':jqXHR } });
    }

    try {
      errorHandler(err, jqXHR);
    } catch (e) {}
    return;
  }


  function handleResponse(jqXHR, textStatus, onSuccess, onError, onRetry) {
    var ret = null;
    var reterr = null;
    try {
      //error from jqXHR
      if (textStatus == "error") {
        var errmsg = $.msajax.defaultErrorMessage || "Error retreiving data.";

        //check for error response from the server
        if (jqXHR.status >= 300 && jqXHR.status < 600) {
          return logError( jqXHR.statusText || msg, onError, jqXHR);
        }

        if (tries++ < 5) return onRetry();

        return logError( msg, onError, jqXHR);
      }

      //not an error response, reset try counter
      tries = 0;

      //check for a redirect from server (usually authentication token expiration).
      if (jqXHR.responseText.indexOf("|pageRedirect||") > 0) {
        location.href = decodeURIComponent(jqXHR.responseText.split("|pageRedirect||")[1].split("|")[0]).split('?')[0];
        return;
      }

      //parse response using ajax enabled parser (if available)
      ret = ((JSON && JSON.parseAjax) || $.parseJSON)(jqXHR.responseText);

      //invalid response
      if (!ret) throw jqXHR.responseText;  

      // d property wrap as of .Net 3.5
      if (ret.d) ret = ret.d;

      //has an error
      reterr = (ret && (ret.error || ret.Error)) || null; //specifically returned an "error"

      if (ret && ret.ExceptionType) { //Microsoft Webservice Exception Response
        reterr = ret
      }

    } catch (err) {
      reterr = {
        'Message': $.msajax.defaultErrorMessage || "Error retreiving data."
        ,'debug': err
      }
    }

    //perform final logic outside try/catch, was catching error in onSuccess/onError callbacks
    if (reterr) {
      logError(reterr, onError, jqXHR);
      return;
    }

    onSuccess(ret, jqXHR);
  }

} (jQuery));

NOTE: I also have a JSON.parseAjax method that is modified from json.org's JS file, that adds handling for the MS "/Date(...)/" dates...

The modified json2.js file isn't included, it uses the script based parser in the case of IE8, as there are instances where the native parser breaks when you extend the prototype of array and/or object, etc.

I've been considering revamping this code to implement the promises interfaces, but it's worked really well for me.

Is it better to use NOT or <> when comparing values?

Because "not ... =" is two operations and "<>" is only one, it is faster to use "<>".

Here is a quick experiment to prove it:

StartTime = Timer
For x = 1 to 100000000
   If 4 <> 3 Then
   End if
Next
WScript.echo Timer-StartTime

StartTime = Timer
For x = 1 to 100000000
   If Not (4 = 3) Then
   End if
Next
WScript.echo Timer-StartTime

The results I get on my machine:

4.783203
5.552734

What is an idempotent operation?

In short, Idempotent operations means that the operation will not result in different results no matter how many times you operate the idempotent operations.

For example, according to the definition of the spec of HTTP, GET, HEAD, PUT, and DELETE are idempotent operations; however POST and PATCH are not. That's why sometimes POST is replaced by PUT.

How to change legend title in ggplot

Just to add to the list (the other options here didn't work for me), you can also use the function update_labels for ggplot:

p <- ggplot(df, aes(x=rating, fill=cond)) + 
           geom_density(alpha=.3) + 
           xlab("NEW RATING TITLE") + 
           ylab("NEW DENSITY TITLE")
update_labels(p, list(colour="MY NEW LEGEND TITLE")

This will also allow you to change x- and y-axis labels, with separate lines:

update_labels(p, list(x="NEW X LABEL",y="NEW Y LABEL")

What is the ultimate postal code and zip regex?

Somebody was asking about list of formatting mailing addresses, and I think this is what he was looking for...

Frank's Compulsive Guide to Postal Addresses: http://www.columbia.edu/~fdc/postal/ Doesn't help much with street-level issues, however.

My work uses a couple of tools to assist with this: - Lexis-Nexis services, including NCOA lookups (you'll get address standardization for "free") - "Melissa Data" http://www.melissadata.com

How to use onClick event on react Link component?

You should use this:

<Link to={this.props.myroute} onClick={hello}>Here</Link>

Or (if method hello lays at this class):

<Link to={this.props.myroute} onClick={this.hello}>Here</Link>

Update: For ES6 and latest if you want to bind some param with click method, you can use this:

    const someValue = 'some';  
....  
    <Link to={this.props.myroute} onClick={() => hello(someValue)}>Here</Link>

Saving to CSV in Excel loses regional date format

Change the date and time settings for your computer in the "short date" format under calendar settings. This will change the format for everything yyyy-mm-dd or however you want it to display; but remember it will look like that even for files saved on your computer.

At least it works.

Java: Static Class?

Private constructor and static methods on a class marked as final.

In Oracle, is it possible to INSERT or UPDATE a record through a view?

YES, you can Update and Insert into view and that edit will be reflected on the original table....
BUT
1-the view should have all the NOT NULL values on the table
2-the update should have the same rules as table... "updating primary key related to other foreign key.. etc"...

Is calculating an MD5 hash less CPU intensive than SHA family functions?

sha1sum is quite a bit faster on Power9 than md5sum

$ uname -mov
#1 SMP Mon May 13 12:16:08 EDT 2019 ppc64le GNU/Linux

$ cat /proc/cpuinfo
processor       : 0
cpu             : POWER9, altivec supported
clock           : 2166.000000MHz
revision        : 2.2 (pvr 004e 1202)

$ ls -l linux-master.tar
-rw-rw-r-- 1 x x 829685760 Jan 29 14:30 linux-master.tar

$ time sha1sum linux-master.tar
10fbf911e254c4fe8e5eb2e605c6c02d29a88563  linux-master.tar

real    0m1.685s
user    0m1.528s
sys     0m0.156s

$ time md5sum linux-master.tar
d476375abacda064ae437a683c537ec4  linux-master.tar

real    0m2.942s
user    0m2.806s
sys     0m0.136s

$ time sum linux-master.tar
36928 810240

real    0m2.186s
user    0m1.917s
sys     0m0.268s

Removing duplicates from a String in Java

To me it looks like everyone is trying way too hard to accomplish this task. All we are concerned about is that it copies 1 copy of each letter if it repeats. Then because we are only concerned if those characters repeat one after the other the nested loops become arbitrary as you can just simply compare position n to position n + 1. Then because this only copies things down when they're different, to solve for the last character you can either append white space to the end of the original string, or just get it to copy the last character of the string to your result.

String removeDuplicate(String s){

    String result = "";

    for (int i = 0; i < s.length(); i++){
        if (i + 1 < s.length() && s.charAt(i) != s.charAt(i+1)){
            result = result + s.charAt(i);
        }
        if (i + 1 == s.length()){
            result = result + s.charAt(i);
        }
    }

    return result;

}

How can I remove file extension from a website address?

Just add an .htaccess file to the root folder of your site (for example, /home/domains/domain.com/htdocs/) with the following content:

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*)$ $1.php

More about how this works in these pages: mod_rewrite guide (introduction, using it), reference documentation

How to convert a string to lower case in Bash?

This is a far faster variation of JaredTS486's approach that uses native Bash capabilities (including Bash versions <4.0) to optimize his approach.

I've timed 1,000 iterations of this approach for a small string (25 characters) and a larger string (445 characters), both for lowercase and uppercase conversions. Since the test strings are predominantly lowercase, conversions to lowercase are generally faster than to uppercase.

I've compared my approach with several other answers on this page that are compatible with Bash 3.2. My approach is far more performant than most approaches documented here, and is even faster than tr in several cases.

Here are the timing results for 1,000 iterations of 25 characters:

Timing results for 1,000 iterations of 445 characters (consisting of the poem "The Robin" by Witter Bynner):

  • 2s for my approach to lowercase; 12s for uppercase
  • 4s for tr to lowercase; 4s for uppercase
  • 20s for Orwellophile's approach to lowercase; 29s for uppercase
  • 75s for ghostdog74's approach to lowercase; 669s for uppercase. It's interesting to note how dramatic the performance difference is between a test with predominant matches vs. a test with predominant misses
  • 467s for technosaurus' approach to lowercase; 449s for uppercase
  • 660s for JaredTS486's approach to lowercase; 660s for uppercase. It's interesting to note that this approach generated continuous page faults (memory swapping) in Bash

Solution:

#!/bin/bash
set -e
set -u

declare LCS="abcdefghijklmnopqrstuvwxyz"
declare UCS="ABCDEFGHIJKLMNOPQRSTUVWXYZ"

function lcase()
{
  local TARGET="${1-}"
  local UCHAR=''
  local UOFFSET=''

  while [[ "${TARGET}" =~ ([A-Z]) ]]
  do
    UCHAR="${BASH_REMATCH[1]}"
    UOFFSET="${UCS%%${UCHAR}*}"
    TARGET="${TARGET//${UCHAR}/${LCS:${#UOFFSET}:1}}"
  done

  echo -n "${TARGET}"
}

function ucase()
{
  local TARGET="${1-}"
  local LCHAR=''
  local LOFFSET=''

  while [[ "${TARGET}" =~ ([a-z]) ]]
  do
    LCHAR="${BASH_REMATCH[1]}"
    LOFFSET="${LCS%%${LCHAR}*}"
    TARGET="${TARGET//${LCHAR}/${UCS:${#LOFFSET}:1}}"
  done

  echo -n "${TARGET}"
}

The approach is simple: while the input string has any remaining uppercase letters present, find the next one, and replace all instances of that letter with its lowercase variant. Repeat until all uppercase letters are replaced.

Some performance characteristics of my solution:

  1. Uses only shell builtin utilities, which avoids the overhead of invoking external binary utilities in a new process
  2. Avoids sub-shells, which incur performance penalties
  3. Uses shell mechanisms that are compiled and optimized for performance, such as global string replacement within variables, variable suffix trimming, and regex searching and matching. These mechanisms are far faster than iterating manually through strings
  4. Loops only the number of times required by the count of unique matching characters to be converted. For example, converting a string that has three different uppercase characters to lowercase requires only 3 loop iterations. For the preconfigured ASCII alphabet, the maximum number of loop iterations is 26
  5. UCS and LCS can be augmented with additional characters

Android SDK Manager gives "Failed to fetch URL https://dl-ssl.google.com/android/repository/repository.xml" error when selecting repository

Open Android SDK Manager and open menu Tools->Options

in Proxy Setting Part Set your proxy and ok

MySQL Query GROUP BY day / month / year

If your search is over several years, and you still want to group monthly, I suggest:

version #1:

SELECT SQL_NO_CACHE YEAR(record_date), MONTH(record_date), COUNT(*)
FROM stats
GROUP BY DATE_FORMAT(record_date, '%Y%m')

version #2 (more efficient):

SELECT SQL_NO_CACHE YEAR(record_date), MONTH(record_date), COUNT(*)
FROM stats
GROUP BY YEAR(record_date)*100 + MONTH(record_date)

I compared these versions on a big table with 1,357,918 rows (), and the 2nd version appears to have better results.

version1 (average of 10 executes): 1.404 seconds
version2 (average of 10 executes): 0.780 seconds

(SQL_NO_CACHE key added to prevent MySQL from CACHING to queries.)

Using Razor within JavaScript

A simple and a good straight-forward example:

<script>
    // This gets the username from the Razor engine and puts it
    // in JavaScript to create a variable I can access from the
    // client side.
    //
    // It's an odd workaraound, but it works.
    @{
        var outScript = "var razorUserName = " + "\"" + @User.Identity.Name + "\"";
    }
    @MvcHtmlString.Create(outScript);
</script>

This creates a script in your page at the location you place the code above which looks like the following:

<script>
    // This gets the username from the Razor engine and puts it
    // in JavaScript to create a variable I can access from
    // client side.
    //
    // It's an odd workaraound, but it works.

    var razorUserName = "daylight";
</script>

Now you have a global JavaScript variable named razorUserName which you can access and use on the client. The Razor engine has obviously extracted the value from @User.Identity.Name (server-side variable) and put it in the code it writes to your script tag.

Style bottom Line in Android

I think you do not need to use shape if I understood you.

If you are looking as shown in following image then use following layout.

enter image description here

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<RelativeLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:background="#1bd4f6"
    android:paddingBottom="4dp" >

    <TextView
        android:layout_width="200dp"
        android:layout_height="wrap_content"
        android:background="#ababb2"
        android:padding="5dp"
        android:text="Hello Android" />
 </RelativeLayout>

 </RelativeLayout>

EDIT

play with these properties you will get result

    android:top="dimension"
    android:right="dimension"
    android:bottom="dimension"
    android:left="dimension"

try like this

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

<item>
    <shape android:shape="rectangle" >
        <solid android:color="#1bd4f6" />
    </shape>
</item>

<item android:top="20px"
    android:left="0px">
    <shape android:shape="line"  >
        <padding android:bottom="1dp" />

        <stroke
            android:dashGap="10px"
            android:dashWidth="10px"
            android:width="1dp"
            android:color="#ababb2" />
    </shape>
</item>

</layer-list>

Google Spreadsheet, Count IF contains a string

You should use

=COUNTIF(A2:A51, "*iPad*")/COUNTA(A2:A51)

Additionally, if you wanted to count more than one element, like iPads OR Kindles, you would use

=SUM(COUNTIF(A2:A51, {"*iPad*", "*kindle*"}))/COUNTA(A2:A51)

in the numerator.

What is the difference between sscanf or atoi to convert a string to an integer?

*scanf() family of functions return the number of values converted. So you should check to make sure sscanf() returns 1 in your case. EOF is returned for "input failure", which means that ssacnf() will never return EOF.

For sscanf(), the function has to parse the format string, and then decode an integer. atoi() doesn't have that overhead. Both suffer from the problem that out-of-range values result in undefined behavior.

You should use strtol() or strtoul() functions, which provide much better error-detection and checking. They also let you know if the whole string was consumed.

If you want an int, you can always use strtol(), and then check the returned value to see if it lies between INT_MIN and INT_MAX.

Inline IF Statement in C#

The literal answer is:

return (value == 1 ? Periods.VariablePeriods : Periods.FixedPeriods);

Note that the inline if statement, just like an if statement, only checks for true or false. If (value == 1) evaluates to false, it might not necessarily mean that value == 2. Therefore it would be safer like this:

return (value == 1
    ? Periods.VariablePeriods
    : (value == 2
        ? Periods.FixedPeriods
        : Periods.Unknown));

If you add more values an inline if will become unreadable and a switch would be preferred:

switch (value)
{
case 1:
    return Periods.VariablePeriods;
case 2:
    return Periods.FixedPeriods;
}

The good thing about enums is that they have a value, so you can use the values for the mapping, as user854301 suggested. This way you can prevent unnecessary branches thus making the code more readable and extensible.

Abstract methods in Python

You have to implement an abstract base class (ABC).

Check python docs

C# - Substring: index and length must refer to a location within the string

Try This:

 int positionOfJPG=url.IndexOf(".jpg");
 string newString = url.Substring(18, url.Length - positionOfJPG);

package javax.servlet.http does not exist

Try:

javac -cp .;"C:\Users\User Name\Tomcat\apache-tomcat-7.0.108\lib\servlet-api.jar" HelloServlet.java

using windows if there are spaces in your class path.

Android: I lost my android key store, what should I do?

No, there is no chance to do that. You just learned how important a backup can be.

how to bind datatable to datagridview in c#

for example we want to set a DataTable 'Users' to DataGridView by followig 2 steps : step 1 - get all Users by :

public DataTable  getAllUsers()
    {
        OracleConnection Connection = new OracleConnection(stringConnection);
        Connection.ConnectionString = stringConnection;
        Connection.Open();

        DataSet dataSet = new DataSet();

        OracleCommand cmd = new OracleCommand("semect * from Users");
        cmd.CommandType = CommandType.Text;
        cmd.Connection = Connection;

        using (OracleDataAdapter dataAdapter = new OracleDataAdapter())
        {
            dataAdapter.SelectCommand = cmd;
            dataAdapter.Fill(dataSet);
        }

        return dataSet.Tables[0];
    }

step 2- set the return result to DataGridView :

public void setTableToDgv(DataGridView DGV, DataTable table)
    {
        DGV.DataSource = table;
    }

using example:

    setTableToDgv(dgv_client,getAllUsers());

Generate a random number in a certain range in MATLAB

You can also use:

round(mod(rand.*max,max-1))+min

Write to .txt file?

Well, you need to first get a good book on C and understand the language.

FILE *fp;
fp = fopen("c:\\test.txt", "wb");
if(fp == null)
   return;
char x[10]="ABCDEFGHIJ";
fwrite(x, sizeof(x[0]), sizeof(x)/sizeof(x[0]), fp);
fclose(fp);

Assign keyboard shortcut to run procedure

The problem that I had with the above is that I wanted to associate a short cut key with a macro in an xlam which has no visible interface. I found that the folllowing worked

To associate a short cut key with a macro

In Excel (not VBA) on the Developer Tab click Macros - no macros will be shown Type the name of the Sub The Options button should then be enabled Click it Ctrl will be the default Hold down Shift and press the letter you want eg Shift and A will associate Ctrl-Shift-A with the Sub

C++ compile error: has initializer but incomplete type

` Please include either of these:

`#include<sstream>`

using std::istringstream; 

How to declare an ArrayList with values?

Use this one:

ArrayList<String> x = new ArrayList(Arrays.asList("abc", "mno"));

Git push existing repo to a new and different remote repo server?

I found a solution using set-url which is concise and fairly easy to understand:

  1. create a new repo at Github
  2. cd into the existing repository on your local machine (if you haven't cloned it yet, then do this first)
  3. git remote set-url origin https://github.com/user/example.git
  4. git push -u origin master

How to get a password from a shell script without echoing

This link is help in defining, * How to read password from use without echo-ing it back to terminal * How to replace each character with * -character.

https://www.tutorialkart.com/bash-shell-scripting/bash-read-username-and-password/

Static vs class functions/variables in Swift classes?

class vs static

class is used inside Reference Type(class):

  • computed property
  • method
  • can be overridden by subclass

static is used inside Reference Type and Value Type(class, enum):

  • computed property and stored property
  • method
  • cannot be changed by subclass
protocol MyProtocol {
//    class var protocolClassVariable : Int { get }//ERROR: Class properties are only allowed within classes
    static var protocolStaticVariable : Int { get }
    
//    class func protocolClassFunc()//ERROR: Class methods are only allowed within classes
    static func protocolStaticFunc()
}

struct ValueTypeStruct: MyProtocol {
    //MyProtocol implementation begin
    static var protocolStaticVariable: Int = 1
    
    static func protocolStaticFunc() {
        
    }
    //MyProtocol implementation end
    
//    class var classVariable = "classVariable"//ERROR: Class properties are only allowed within classes
    static var staticVariable = "staticVariable"

//    class func classFunc() {} //ERROR: Class methods are only allowed within classes
    static func staticFunc() {}
}

class ReferenceTypeClass: MyProtocol {
    //MyProtocol implementation begin
    static var protocolStaticVariable: Int = 2
    
    static func protocolStaticFunc() {
        
    }
    //MyProtocol implementation end
    
    var variable = "variable"

//    class var classStoredPropertyVariable = "classVariable"//ERROR: Class stored properties not supported in classes

    class var classComputedPropertyVariable: Int {
        get {
            return 1
        }
    }

    static var staticStoredPropertyVariable = "staticVariable"

    static var staticComputedPropertyVariable: Int {
        get {
            return 1
        }
    }

    class func classFunc() {}
    static func staticFunc() {}
}

final class FinalSubReferenceTypeClass: ReferenceTypeClass {
    override class var classComputedPropertyVariable: Int {
        get {
            return 2
        }
    }
    override class func classFunc() {}
}

//class SubFinalSubReferenceTypeClass: FinalSubReferenceTypeClass {}// ERROR: Inheritance from a final class

[Reference vs Value Type]

What is the difference between parseInt() and Number()?

One minor difference is what they convert of undefined or null,

Number() Or Number(null) // returns 0

while

parseInt() Or parseInt(null) // returns NaN

htaccess redirect if URL contains a certain string

RewriteCond %{REQUEST_URI} foobar
RewriteRule .* index.php

or some variant thereof.

How to scroll to bottom in a ScrollView on activity startup

After initializing your UI component and fill it with data. add those line to your on create method

Runnable runnable=new Runnable() {
        @Override
        public void run() {
            scrollView.fullScroll(ScrollView.FOCUS_DOWN);
        }
    };
    scrollView.post(runnable);

How to extract one column of a csv file

csvtool col 2 file.csv 

where 2 is the column you are interested in

you can also do

csvtool col 1,2 file.csv 

to do multiple columns

How to loop and render elements in React.js without an array of objects to map?

Array.from() takes an iterable object to convert to an array and an optional map function. You could create an object with a .length property as follows:

return Array.from({length: this.props.level}, (item, index) => 
  <span className="indent" key={index}></span>
);

multiprocessing.Pool: When to use apply, apply_async or map?

Here is an overview in a table format in order to show the differences between Pool.apply, Pool.apply_async, Pool.map and Pool.map_async. When choosing one, you have to take multi-args, concurrency, blocking, and ordering into account:

                  | Multi-args   Concurrence    Blocking     Ordered-results
---------------------------------------------------------------------
Pool.map          | no           yes            yes          yes
Pool.map_async    | no           yes            no           yes
Pool.apply        | yes          no             yes          no
Pool.apply_async  | yes          yes            no           no
Pool.starmap      | yes          yes            yes          yes
Pool.starmap_async| yes          yes            no           no

Notes:

  • Pool.imap and Pool.imap_async – lazier version of map and map_async.

  • Pool.starmap method, very much similar to map method besides it acceptance of multiple arguments.

  • Async methods submit all the processes at once and retrieve the results once they are finished. Use get method to obtain the results.

  • Pool.map(or Pool.apply)methods are very much similar to Python built-in map(or apply). They block the main process until all the processes complete and return the result.

Examples:

map

Is called for a list of jobs in one time

results = pool.map(func, [1, 2, 3])

apply

Can only be called for one job

for x, y in [[1, 1], [2, 2]]:
    results.append(pool.apply(func, (x, y)))

def collect_result(result):
    results.append(result)

map_async

Is called for a list of jobs in one time

pool.map_async(func, jobs, callback=collect_result)

apply_async

Can only be called for one job and executes a job in the background in parallel

for x, y in [[1, 1], [2, 2]]:
    pool.apply_async(worker, (x, y), callback=collect_result)

starmap

Is a variant of pool.map which support multiple arguments

pool.starmap(func, [(1, 1), (2, 1), (3, 1)])

starmap_async

A combination of starmap() and map_async() that iterates over iterable of iterables and calls func with the iterables unpacked. Returns a result object.

pool.starmap_async(calculate_worker, [(1, 1), (2, 1), (3, 1)], callback=collect_result)

Reference:

Find complete documentation here: https://docs.python.org/3/library/multiprocessing.html

Returning a value from callback function in Node.js

I am facing small trouble in returning a value from callback function in Node.js

This is not a "small trouble", it is actually impossible to "return" a value in the traditional sense from an asynchronous function.

Since you cannot "return the value" you must call the function that will need the value once you have it. @display_name already answered your question, but I just wanted to point out that the return in doCall is not returning the value in the traditional way. You could write doCall as follow:

function doCall(urlToCall, callback) {
    urllib.request(urlToCall, { wd: 'nodejs' }, function (err, data, response) {                              
        var statusCode = response.statusCode;
        finalData = getResponseJson(statusCode, data.toString());
        // call the function that needs the value
        callback(finalData);
        // we are done
        return;
    });
}

Line callback(finalData); is what calls the function that needs the value that you got from the async function. But be aware that the return statement is used to indicate that the function ends here, but it does not mean that the value is returned to the caller (the caller already moved on.)

Proxies with Python 'Requests' module

You can refer to the proxy documentation here.

If you need to use a proxy, you can configure individual requests with the proxies argument to any request method:

import requests

proxies = {
  "http": "http://10.10.1.10:3128",
  "https": "https://10.10.1.10:1080",
}

requests.get("http://example.org", proxies=proxies)

To use HTTP Basic Auth with your proxy, use the http://user:[email protected]/ syntax:

proxies = {
    "http": "http://user:[email protected]:3128/"
}

ClientScript.RegisterClientScriptBlock?

See if the below helps you:

I was using the following earlier:

ClientScript.RegisterClientScriptBlock(Page.GetType(), "AlertMsg", "<script language='javascript'>alert('The Web Policy need to be accepted to submit the new assessor information.');</script>");

After implementing AJAX in this page, it stopped working. After reading your blog, I changed the above to:

ScriptManager.RegisterClientScriptBlock(imgBtnSubmit, this.GetType(), "AlertMsg", "<script language='javascript'>alert('The Web Policy need to be accepted to submit the new assessor information.');</script>", false);

This is working perfectly fine.

(It’s .NET 2.0 Framework, I am using)

How do I check that multiple keys are in a dict in a single pass?

You can use .issubset() as well

>>> {"key1", "key2"}.issubset({"key1":1, "key2":2, "key3": 3})
True
>>> {"key4", "key2"}.issubset({"key1":1, "key2":2, "key3": 3})
False
>>>

Xcode couldn't find any provisioning profiles matching

What fixed it for me was plugging my iPhone and allowing it as a simulator destination. Doing so required my to register my iPhone in Apple Dev account and once that was done and I ran my project from Xcode on my iPhone everything fixed itself.

  1. Connect your iPhone to your Mac
  2. Xcode>Window>Devices & Simulators
  3. Add new under Devices and make sure "show are run destination" is ticked
  4. Build project and run it on your iPhone

How to determine the Schemas inside an Oracle Data Pump Export file

You need to search for OWNER_NAME.

cat -v dumpfile.dmp | grep -o '<OWNER_NAME>.*</OWNER_NAME>' | uniq -u

cat -v turn the dumpfile into visible text.

grep -o shows only the match so we don't see really long lines

uniq -u removes duplicate lines so you see less output.

This works pretty well, even on large dump files, and could be tweaked for usage in a script.

How can foreign key constraints be temporarily disabled using T-SQL?

One script to rule them all: this combines truncate and delete commands with sp_MSforeachtable so that you can avoid dropping and recreating constraints - just specify the tables that need to be deleted rather than truncated and for my purposes I have included an extra schema filter for good measure (tested in 2008r2)

declare @schema nvarchar(max) = 'and Schema_Id=Schema_id(''Value'')'
declare @deletiontables nvarchar(max) = '(''TableA'',''TableB'')'
declare @truncateclause nvarchar(max) = @schema + ' and o.Name not in ' +  + @deletiontables;
declare @deleteclause nvarchar(max) = @schema + ' and o.Name in ' + @deletiontables;        

exec sp_MSforeachtable 'alter table ? nocheck constraint all', @whereand=@schema
exec sp_MSforeachtable 'truncate table ?', @whereand=@truncateclause
exec sp_MSforeachtable 'delete from ?', @whereand=@deleteclause
exec sp_MSforeachtable 'alter table ? with check check constraint all', @whereand=@schema

How to generate unique IDs for form labels in React?

The id should be placed inside of componentWillMount (update for 2018) constructor, not render. Putting it in render will re-generate new ids unnecessarily.

If you're using underscore or lodash, there is a uniqueId function, so your resulting code should be something like:

constructor(props) {
    super(props);
    this.id = _.uniqueId("prefix-");
}

render() { 
  const id = this.id;
  return (
    <div>
        <input id={id} type="checkbox" />
        <label htmlFor={id}>label</label>
    </div>
  );
}

2019 Hooks update:

import React, { useState } from 'react';
import _uniqueId from 'lodash/uniqueId';

const MyComponent = (props) => {
  // id will be set once when the component initially renders, but never again
  // (unless you assigned and called the second argument of the tuple)
  const [id] = useState(_uniqueId('prefix-'));
  return (
    <div>
      <input id={id} type="checkbox" />
      <label htmlFor={id}>label</label>
    </div>
  );
}

How to copy a file to another path?

string directoryPath = Path.GetDirectoryName(destinationFileName);

// If directory doesn't exist create one
if (!Directory.Exists(directoryPath))
{
DirectoryInfo di = Directory.CreateDirectory(directoryPath);
}

File.Copy(sourceFileName, destinationFileName);

Show default value in Spinner in android

Spinner don't support Hint, i recommend you to make a custom spinner adapter.

check this link : https://stackoverflow.com/a/13878692/1725748

Import an existing git project into GitLab?

Moving a project from GitHub to GitLab including issues, pull requests Wiki, Milestones, Labels, Release notes and comments

There is a thorough instruction on GitLab Docs:

https://docs.gitlab.com/ee/user/project/import/github.html

tl;dr

  • Ensure that any GitHub users who you want to map to GitLab users have either:

    • A GitLab account that has logged in using the GitHub icon - or -
    • A GitLab account with an email address that matches the public email address of the GitHub user
  • From the top navigation bar, click + and select New project.

  • Select the Import project tab and then select GitHub.
  • Select the first button to List your GitHub repositories. You are redirected to a page on github.com to authorize the GitLab application.
  • Click Authorize gitlabhq. You are redirected back to GitLab's Import page and all of your GitHub repositories are listed.
  • Continue on to selecting which repositories to import.

But Please read the GitLab Docs page for details and hooks!

(it's not much)

How can I test if a letter in a string is uppercase or lowercase using JavaScript?

function checkCase(c){
    var u = c.toUpperCase();
    return (c.toLowerCase() === u ? -1 : (c === u ? 1 : 0));
};

Based on Sonic Beard comment to the main answer. I changed the logic in the result:

  • 0: Lowercase

  • 1: Uppercase

  • -1: neither

Comparing strings in Java

You need both getText() - which returns an Editable and toString() - to convert that to a String for matching. So instead of: passw1.toString().equalsIgnoreCase("1234") you need passw1.getText().toString().equalsIgnoreCase("1234").

How to get the selected radio button’s value?

Since jQuery 1.8, the correct syntax for the query is

$('input[name="genderS"]:checked').val();

Not $('input[@name="genderS"]:checked').val(); anymore, which was working in jQuery 1.7 (with the @).

Apache - MySQL Service detected with wrong path. / Ports already in use

its because you probaly installed wamp server and uninstall it but wampmysql.exe still running and using the default mysql port go to msconfig under services tab uncheck wampmysqld to deactivate it reboot the computer should work

Ruby on Rails: Clear a cached page

If you're doing fragment caching, you can manually break the cache by updating your cache key, like so:

Version #1

<% cache ['cool_name_for_cache_key', 'v1'] do %>

Version #2

<% cache ['cool_name_for_cache_key', 'v2'] do %>

Or you can have the cache automatically reset based on the state of a non-static object, such as an ActiveRecord object, like so:

<% cache @user_object do %>

With this ^ method, any time the user object is updated, the cache will automatically be reset.

Find when a file was deleted in Git

Git log but you need to prefix the path with --

Eg:

dan-mac:test dani$ git log file1.txt
fatal: ambiguous argument 'file1.txt': unknown revision or path not in the working tree.

dan-mac:test dani$ git log -- file1.txt
 commit 0f7c4e1c36e0b39225d10b26f3dea40ad128b976
 Author: Daniel Palacio <[email protected]>
 Date:   Tue Jul 26 23:32:20 2011 -0500

 foo

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 13: ordinal not in range(128)

You can try this also:

import sys
reload(sys)
sys.setdefaultencoding('utf8')

How to convert a list of numbers to jsonarray in Python

import json
row = [1L,[0.1,0.2],[[1234L,1],[134L,2]]]
row_json = json.dumps(row)

java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter

In your config.ini file of eclipse eclipse\configuration\config.ini check this three things:

osgi.framework=file\:plugins\\org.eclipse.osgi_3.4.2.R34x_v20080826-1230.jar
osgi.bundles=reference\:file\:org.eclipse.equinox.simpleconfigurator_1.0.0.v20080604.jar@1\:start
org.eclipse.equinox.simpleconfigurator.configUrl=file\:org.eclipse.equinox.simpleconfigurator\\bundles.info

And check whether these jars are in place or not, the jar files depend upon your version of eclipse .

ssh : Permission denied (publickey,gssapi-with-mic)

Tried a lot of things, it did not help.

It get access in a simple way:

eval $(ssh-agent) > /dev/null
killall ssh-agent
eval `ssh-agent`
ssh-add ~/.ssh/id_rsa

Note that at the end of the ssh-add -L output must be not a path to the key, but your email.

Get current URL from IFRAME

Hope this will help some how in your case, I suffered with the exact same problem, and just used localstorage to share the data between parent window and iframe. So in parent window you can:

localStorage.setItem("url", myUrl);

And in code where iframe source is just get this data from localstorage:

localStorage.getItem('url');

Saved me a lot of time. As far as i can see the only condition is access to the parent page code. Hope this will help someone.

vector vs. list in STL

Preserving the validity of iterators is one reason to use a list. Another is when you don't want a vector to reallocate when pushing items. This can be managed by an intelligent use of reserve(), but in some cases it might be easier or more feasible to just use a list.

Elasticsearch error: cluster_block_exception [FORBIDDEN/12/index read-only / allow delete (api)], flood stage disk watermark exceeded

Only changing the settings with the following command did not work in my environment:

curl -XPUT -H "Content-Type: application/json" http://localhost:9200/_all/_settings -d '{"index.blocks.read_only_allow_delete": null}'

I had to also ran the Force Merge API command:

curl -X POST "localhost:9200/my-index-000001/_forcemerge?pretty"

ref: Force Merge API

error code 1292 incorrect date value mysql

I was having the same issue in Workbench plus insert query from C# application. In my case using ISO format solve the issue

string value = date.ToString("yyyy-MM-dd HH:mm:ss");

Checking if sys.argv[x] is defined

Pretty close to what the originator was trying to do. Here is a function I use:

def get_arg(index):
    try:
        sys.argv[index]
    except IndexError:
        return ''
    else:
        return sys.argv[index]

So a usage would be something like:

if __name__ == "__main__":
    banner(get_arg(1),get_arg(2))

get next and previous day with PHP

Php script -1****its to Next Date

<?php

$currentdate=date('Y-m-d');


$date_arr=explode('-',$currentdate);


$next_date=
Date("Y-m-d",mktime(0,0,0,$date_arr[1],$date_arr[2]+1,$date_arr[0]));



echo $next_date;
?>**

**Php script -1****its to Next year**


<?php

$currentdate=date('Y-m-d');


$date_arr=explode('-',$currentdate);


$next_date=
Date("Y-m-d",mktime(0,0,0,$date_arr[1],$date_arr[2],$date_arr[0]+1));



echo $next_date;
?>

What was the strangest coding standard rule that you were forced to follow?

To NEVER remove any code when making changes. We were told to comment all changes. Bear in mind we use source control. This policy didn't last long because developers were in an uproar about it and how it would make the code unreadable.

How to uninstall jupyter

If you are using jupyter notebook, You can remove it like this:

pip uninstall notebook

You should use conda uninstall if you installed it with conda.

How to register ASP.NET 2.0 to web server(IIS7)?

I got it resolved by doing Repir on .NET framework Extended, in Add/Remove program ;

Using win2008R2, .NET framework 4.0

Maven command to determine which settings.xml file Maven is using

Start maven with -X option (debug) and examine the beginning of the output. There should be something like this:

...
[INFO] Error stacktraces are turned on.
[DEBUG] Reading global settings from c:\....\apache-maven-3.0.3\conf\settings.xml
[DEBUG] Reading user settings from c:\....\.m2\settings.xml
[DEBUG] Using local repository at C:\....\repository
...

(Original directory names are removed by me)

How to create a user in Django?

Have you confirmed that you are passing actual values and not None?

from django.shortcuts import render

def createUser(request):
    userName = request.REQUEST.get('username', None)
    userPass = request.REQUEST.get('password', None)
    userMail = request.REQUEST.get('email', None)

    # TODO: check if already existed
    if userName and userPass and userMail:
       u,created = User.objects.get_or_create(userName, userMail)
       if created:
          # user was created
          # set the password here
       else:
          # user was retrieved
    else:
       # request was empty

    return render(request,'home.html')

JQuery: Change value of hidden input field

It's simple as:

$('#action').val("1");

#action is hidden input field id.

Best practice for storing and protecting private API keys in applications

Another approach is to not have the secret on the device in the first place! See Mobile API Security Techniques (especially part 3).

Using the time honored tradition of indirection, share the secret between your API endpoint and an app authentication service.

When your client wants to make an API call, it asks the app auth service to authenticate it (using strong remote attestation techniques), and it receives a time limited (usually JWT) token signed by the secret.

The token is sent with each API call where the endpoint can verify its signature before acting on the request.

The actual secret is never present on the device; in fact, the app never has any idea if it is valid or not, it juts requests authentication and passes on the resulting token. As a nice benefit from indirection, if you ever want to change the secret, you can do so without requiring users to update their installed apps.

So if you want to protect your secret, not having it in your app in the first place is a pretty good way to go.

MySQL: #126 - Incorrect key file for table

Try to run a repair command for each one of the tables involved in the query.

Use MySQL administrator, go to Catalog -> Select your Catalog -> Select a table -> Click the Maintenance button -> Repair -> Use FRM.

Python - How to cut a string in Python?

string = 'http://www.domain.com/?s=some&two=20'
cut_string = string.split('&')
new_string = cut_string[0]
print(new_string)

find all subsets that sum to a particular value

This my program in ruby . It will return arrays, each holding the subsequences summing to the provided target value.

array = [1, 3, 4, 2, 7, 8, 9]

0..array.size.times.each do |i| 
  array.combination(i).to_a.each { |a| print a if a.inject(:+) == 9} 
end

how to prevent adding duplicate keys to a javascript array

You can try this:

var names = ["Mike","Matt","Nancy","Adam","Jenny","Nancy","Carl"];
var uniqueNames = [];
$.each(names, function(i, el){
if($.inArray(el, uniqueNames) === -1) uniqueNames.push(el);
});

Easiest way to find duplicate values in a JavaScript array

How ViewBag in ASP.NET MVC works

It's a dynamic object, meaning you can add properties to it in the controller, and read them later in the view, because you are essentially creating the object as you do, a feature of the dynamic type. See this MSDN article on dynamics. See this article on it's usage in relation to MVC.

If you wanted to use this for web forms, add a dynamic property to a base page class like so:

public class BasePage : Page
{

    public dynamic ViewBagProperty
    {
        get;
        set;
    }
}

Have all of your pages inherit from this. You should be able to, in your ASP.NET markup, do:

<%= ViewBagProperty.X %>

That should work. If not, there are ways to work around it.

Android Studio Rendering Problems : The following classes could not be found

I had to change my values/styles.xml to

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">

Before that change, it was without 'Base'.

(IntelliJ IDEA 2017.2.4)

Clear android application user data

The command pm clear com.android.browser requires root permission.
So, run su first.

Here is the sample code:

private static final String CHARSET_NAME = "UTF-8";
String cmd = "pm clear com.android.browser";

ProcessBuilder pb = new ProcessBuilder().redirectErrorStream(true).command("su");
Process p = pb.start();

// We must handle the result stream in another Thread first
StreamReader stdoutReader = new StreamReader(p.getInputStream(), CHARSET_NAME);
stdoutReader.start();

out = p.getOutputStream();
out.write((cmd + "\n").getBytes(CHARSET_NAME));
out.write(("exit" + "\n").getBytes(CHARSET_NAME));
out.flush();

p.waitFor();
String result = stdoutReader.getResult();

The class StreamReader:

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.concurrent.CountDownLatch;

class StreamReader extends Thread {
    private InputStream is;
    private StringBuffer mBuffer;
    private String mCharset;
    private CountDownLatch mCountDownLatch;

    StreamReader(InputStream is, String charset) {
        this.is = is;
        mCharset = charset;
        mBuffer = new StringBuffer("");
        mCountDownLatch = new CountDownLatch(1);
    }

    String getResult() {
        try {
            mCountDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return mBuffer.toString();
    }

    @Override
    public void run() {
        InputStreamReader isr = null;
        try {
            isr = new InputStreamReader(is, mCharset);
            int c = -1;
            while ((c = isr.read()) != -1) {
                mBuffer.append((char) c);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (isr != null)
                    isr.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            mCountDownLatch.countDown();
        }
    }
}

Copy map values to vector in STL

Here is what I would do.
Also I would use a template function to make the construction of select2nd easier.

#include <map>
#include <vector>
#include <algorithm>
#include <memory>
#include <string>

/*
 * A class to extract the second part of a pair
 */   
template<typename T>
struct select2nd
{
    typename T::second_type operator()(T const& value) const
    {return value.second;}
};

/*
 * A utility template function to make the use of select2nd easy.
 * Pass a map and it automatically creates a select2nd that utilizes the
 * value type. This works nicely as the template functions can deduce the
 * template parameters based on the function parameters. 
 */
template<typename T>
select2nd<typename T::value_type> make_select2nd(T const& m)
{
    return select2nd<typename T::value_type>();
}

int main()
{
    std::map<int,std::string>   m;
    std::vector<std::string>    v;

    /*
     * Please note: You must use std::back_inserter()
     *              As transform assumes the second range is as large as the first.
     *              Alternatively you could pre-populate the vector.
     *
     * Use make_select2nd() to make the function look nice.
     * Alternatively you could use:
     *    select2nd<std::map<int,std::string>::value_type>()
     */   
    std::transform(m.begin(),m.end(),
                   std::back_inserter(v),
                   make_select2nd(m)
                  );
}

LINQ Joining in C# with multiple conditions

As far as I know you can only join this way:

var query = from obj_i in set1
join obj_j in set2 on 
    new { 
      JoinProperty1 = obj_i.SomeField1,
      JoinProperty2 = obj_i.SomeField2,
      JoinProperty3 = obj_i.SomeField3,
      JoinProperty4 = obj_i.SomeField4
    } 
    equals 
    new { 
      JoinProperty1 = obj_j.SomeOtherField1,
      JoinProperty2 = obj_j.SomeOtherField2,
      JoinProperty3 = obj_j.SomeOtherField3,
      JoinProperty4 = obj_j.SomeOtherField4
    }

The main requirements are: Property names, types and order in the anonymous objects you're joining on must match.

You CAN'T use ANDs, ORs, etc. in joins. Just object1 equals object2.

More advanced stuff in this LinqPad example:

class c1 
    {
    public int someIntField;
    public string someStringField;
    }
    
class c2 
    {
    public Int64 someInt64Property {get;set;}
    private object someField;
    public string someStringFunction(){return someField.ToString();}
    }
    
void Main()
{
    var set1 = new List<c1>();
    var set2 = new List<c2>();
    
    var query = from obj_i in set1
    join obj_j in set2 on 
        new { 
                JoinProperty1 = (Int64) obj_i.someIntField,
                JoinProperty2 = obj_i.someStringField
            } 
        equals 
        new { 
                JoinProperty1 = obj_j.someInt64Property,
                JoinProperty2 = obj_j.someStringFunction()
            }
    select new {obj1 = obj_i, obj2 = obj_j};
}

Addressing names and property order is straightforward, addressing types can be achieved via casting/converting/parsing/calling methods etc. This might not always work with LINQ to EF or SQL or NHibernate, most method calls definitely won't work and will fail at run-time, so YMMV (Your Mileage May Vary). This is because they are copied to public read-only properties in the anonymous objects, so as long as your expression produces values of correct type the join property - you should be fine.

Validating input using java.util.Scanner

Here's a minimalist way to do it.

System.out.print("Please enter an integer: ");
while(!scan.hasNextInt()) scan.next();
int demoInt = scan.nextInt();

What is the simplest C# function to parse a JSON string into an object?

DataContractJsonSerializer serializer = 
    new DataContractJsonSerializer(typeof(YourObjectType));

YourObjectType yourObject = (YourObjectType)serializer.ReadObject(jsonStream);

You could also use the JavaScriptSerializer, but DataContractJsonSerializer is supposedly better able to handle complex types.

Oddly enough JavaScriptSerializer was once deprecated (in 3.5) and then resurrected because of ASP.NET MVC (in 3.5 SP1). That would definitely be enough to shake my confidence and lead me to use DataContractJsonSerializer since it is hard baked for WCF.

How to use the curl command in PowerShell?

In Powershell 3.0 and above there is both a Invoke-WebRequest and Invoke-RestMethod. Curl is actually an alias of Invoke-WebRequest in PoSH. I think using native Powershell would be much more appropriate than curl, but it's up to you :).

Invoke-WebRequest MSDN docs are here: https://technet.microsoft.com/en-us/library/hh849901.aspx?f=255&MSPPError=-2147217396

Invoke-RestMethod MSDN docs are here: https://technet.microsoft.com/en-us/library/hh849971.aspx?f=255&MSPPError=-2147217396

How to make cross domain request

If you're willing to transmit some data and that you don't need to be secured (any public infos) you can use a CORS proxy, it's very easy, you'll not have to change anything in your code or in server side (especially of it's not your server like the Yahoo API or OpenWeather). I've used it to fetch JSON files with an XMLHttpRequest and it worked fine.

Return HTTP status code 201 in flask

You can use Response to return any http status code.

> from flask import Response
> return Response("{'a':'b'}", status=201, mimetype='application/json')

Convert NaN to 0 in javascript

Something simpler and effective for anything :

function getNum(val) {
   val = +val || 0
   return val;
}

...which will convert a from any "falsey" value to 0.

The "falsey" values are:

  • false
  • null
  • undefined
  • 0
  • "" ( empty string )
  • NaN ( Not a Number )

Save file to specific folder with curl command

This option comes in curl 7.73.0:

curl --create-dirs -O --output-dir /tmp/receipes https://example.com/pancakes.jpg

Fill drop down list on selection of another drop down list

enter image description here

enter image description here

enter image description here

Model:

namespace MvcApplicationrazor.Models
{
    public class CountryModel
    {
        public List<State> StateModel { get; set; }
        public SelectList FilteredCity { get; set; }
    }
    public class State
    {
        public int Id { get; set; }
        public string StateName { get; set; }
    }
    public class City
    {
        public int Id { get; set; }
        public int StateId { get; set; }
        public string CityName { get; set; }
    }
}   

Controller:

public ActionResult Index()
        {
            CountryModel objcountrymodel = new CountryModel();
            objcountrymodel.StateModel = new List<State>();
            objcountrymodel.StateModel = GetAllState();
            return View(objcountrymodel);
        }


        //Action result for ajax call
        [HttpPost]
        public ActionResult GetCityByStateId(int stateid)
        {
            List<City> objcity = new List<City>();
            objcity = GetAllCity().Where(m => m.StateId == stateid).ToList();
            SelectList obgcity = new SelectList(objcity, "Id", "CityName", 0);
            return Json(obgcity);
        }
        // Collection for state
        public List<State> GetAllState()
        {
            List<State> objstate = new List<State>();
            objstate.Add(new State { Id = 0, StateName = "Select State" });
            objstate.Add(new State { Id = 1, StateName = "State 1" });
            objstate.Add(new State { Id = 2, StateName = "State 2" });
            objstate.Add(new State { Id = 3, StateName = "State 3" });
            objstate.Add(new State { Id = 4, StateName = "State 4" });
            return objstate;
        }
        //collection for city
        public List<City> GetAllCity()
        {
            List<City> objcity = new List<City>();
            objcity.Add(new City { Id = 1, StateId = 1, CityName = "City1-1" });
            objcity.Add(new City { Id = 2, StateId = 2, CityName = "City2-1" });
            objcity.Add(new City { Id = 3, StateId = 4, CityName = "City4-1" });
            objcity.Add(new City { Id = 4, StateId = 1, CityName = "City1-2" });
            objcity.Add(new City { Id = 5, StateId = 1, CityName = "City1-3" });
            objcity.Add(new City { Id = 6, StateId = 4, CityName = "City4-2" });
            return objcity;
        }

View:

@model MvcApplicationrazor.Models.CountryModel
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<script language="javascript" type="text/javascript">
    function GetCity(_stateId) {
        var procemessage = "<option value='0'> Please wait...</option>";
        $("#ddlcity").html(procemessage).show();
        var url = "/Test/GetCityByStateId/";

        $.ajax({
            url: url,
            data: { stateid: _stateId },
            cache: false,
            type: "POST",
            success: function (data) {
                var markup = "<option value='0'>Select City</option>";
                for (var x = 0; x < data.length; x++) {
                    markup += "<option value=" + data[x].Value + ">" + data[x].Text + "</option>";
                }
                $("#ddlcity").html(markup).show();
            },
            error: function (reponse) {
                alert("error : " + reponse);
            }
        });

    }
</script>
<h4>
 MVC Cascading Dropdown List Using Jquery</h4>
@using (Html.BeginForm())
{
    @Html.DropDownListFor(m => m.StateModel, new SelectList(Model.StateModel, "Id", "StateName"), new { @id = "ddlstate", @style = "width:200px;", @onchange = "javascript:GetCity(this.value);" })
    <br />
    <br />
    <select id="ddlcity" name="ddlcity" style="width: 200px">

    </select>

    <br /><br />
  }

Resolve host name to an ip address

Try tracert to resolve the hostname. IE you have Ip address 8.8.8.8 so you would use; tracert 8.8.8.8

How to restart Postgresql

On Windows :

1-Open Run Window by Winkey + R

2-Type services.msc

3-Search Postgres service based on version installed.

4-Click stop, start or restart the service option.

On Linux :

sudo systemctl restart postgresql

also instead of "restart" you can replace : status, stop or status.

Deserializing a JSON file with JavaScriptSerializer()

For .Net 4+:

string s = "{ \"user\" : {    \"id\" : 12345,    \"screen_name\" : \"twitpicuser\"}}";

var serializer = new JavaScriptSerializer();
dynamic usr = serializer.DeserializeObject(s);
var UserId = usr["user"]["id"];

For .Net 2/3.5: This code should work on JSON with 1 level

samplejson.aspx

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Globalization" %>
<%@ Import Namespace="System.Web.Script.Serialization" %>
<%@ Import Namespace="System.Collections.Generic" %>
<%
string s = "{ \"id\" : 12345,    \"screen_name\" : \"twitpicuser\"}";
var serializer = new JavaScriptSerializer();
Dictionary<string, object> result = (serializer.DeserializeObject(s) as Dictionary<string, object>);
var UserId = result["id"];
 %>
 <%=UserId %>

And for a 2 level JSON:

sample2.aspx

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Globalization" %>
<%@ Import Namespace="System.Web.Script.Serialization" %>
<%@ Import Namespace="System.Collections.Generic" %>
<%
string s = "{ \"user\" : {    \"id\" : 12345,    \"screen_name\" : \"twitpicuser\"}}";
var serializer = new JavaScriptSerializer();
Dictionary<string, object> result = (serializer.DeserializeObject(s) as Dictionary<string, object>);
Dictionary<string, object> usr = (result["user"] as Dictionary<string, object>);
var UserId = usr["id"];
 %>
 <%= UserId %>

How to center an image horizontally and align it to the bottom of the container?

have you tried:

.image_block{
text-align: center;
vertical-align: bottom;
}

How to get the Mongo database specified in connection string in C#

The answer below is apparently obsolete now, but works with older drivers. See comments.

If you have the connection string you could also use MongoDatabase directly:

var db =  MongoDatabase.Create(connectionString);
var coll = db.GetCollection("MyCollection");

Could not resolve all dependencies for configuration ':classpath'

I'm using Gradle plugin 3.0.1 and saw this error. Not sure what caused this but the solution that works for me is to stop the running Gradle daemon by ./gradlew --stop.

What is this Javascript "require"?

Alright, so let's first start with making the distinction between Javascript in a web browser, and Javascript on a server (CommonJS and Node).

Javascript is a language traditionally confined to a web browser with a limited global context defined mostly by what came to be known as the Document Object Model (DOM) level 0 (the Netscape Navigator Javascript API).

Server-side Javascript eliminates that restriction and allows Javascript to call into various pieces of native code (like the Postgres library) and open sockets.

Now require() is a special function call defined as part of the CommonJS spec. In node, it resolves libraries and modules in the Node search path, now usually defined as node_modules in the same directory (or the directory of the invoked javascript file) or the system-wide search path.

To try to answer the rest of your question, we need to use a proxy between the code running in the the browser and the database server.

Since we are discussing Node and you are already familiar with how to run a query from there, it would make sense to use Node as that proxy.

As a simple example, we're going to make a URL that returns a few facts about a Beatle, given a name, as JSON.

/* your connection code */

var express = require('express');
var app = express.createServer();
app.get('/beatles/:name', function(req, res) {
    var name = req.params.name || '';
    name = name.replace(/[^a-zA_Z]/, '');
    if (!name.length) {
        res.send({});
    } else {
        var query = client.query('SELECT * FROM BEATLES WHERE name =\''+name+'\' LIMIT 1');
        var data = {};
        query.on('row', function(row) {
            data = row;
            res.send(data);
        });
    };
});
app.listen(80, '127.0.0.1');

How do I invoke a Java method when given the method name as a string?

To complete my colleague's answers, You might want to pay close attention to:

  • static or instance calls (in one case, you do not need an instance of the class, in the other, you might need to rely on an existing default constructor that may or may not be there)
  • public or non-public method call (for the latter,you need to call setAccessible on the method within an doPrivileged block, other findbugs won't be happy)
  • encapsulating into one more manageable applicative exception if you want to throw back the numerous java system exceptions (hence the CCException in the code below)

Here is an old java1.4 code which takes into account those points:

/**
 * Allow for instance call, avoiding certain class circular dependencies. <br />
 * Calls even private method if java Security allows it.
 * @param aninstance instance on which method is invoked (if null, static call)
 * @param classname name of the class containing the method 
 * (can be null - ignored, actually - if instance if provided, must be provided if static call)
 * @param amethodname name of the method to invoke
 * @param parameterTypes array of Classes
 * @param parameters array of Object
 * @return resulting Object
 * @throws CCException if any problem
 */
public static Object reflectionCall(final Object aninstance, final String classname, final String amethodname, final Class[] parameterTypes, final Object[] parameters) throws CCException
{
    Object res;// = null;
    try {
        Class aclass;// = null;
        if(aninstance == null)
        {
            aclass = Class.forName(classname);
        }
        else
        {
            aclass = aninstance.getClass();
        }
        //Class[] parameterTypes = new Class[]{String[].class};
    final Method amethod = aclass.getDeclaredMethod(amethodname, parameterTypes);
        AccessController.doPrivileged(new PrivilegedAction() {
    public Object run() {
                amethod.setAccessible(true);
                return null; // nothing to return
            }
        });
        res = amethod.invoke(aninstance, parameters);
    } catch (final ClassNotFoundException e) {
        throw new CCException.Error(PROBLEM_TO_ACCESS+classname+CLASS, e);
    } catch (final SecurityException e) {
        throw new CCException.Error(PROBLEM_TO_ACCESS+classname+GenericConstants.HASH_DIESE+ amethodname + METHOD_SECURITY_ISSUE, e);
    } catch (final NoSuchMethodException e) {
        throw new CCException.Error(PROBLEM_TO_ACCESS+classname+GenericConstants.HASH_DIESE+ amethodname + METHOD_NOT_FOUND, e);
    } catch (final IllegalArgumentException e) {
        throw new CCException.Error(PROBLEM_TO_ACCESS+classname+GenericConstants.HASH_DIESE+ amethodname + METHOD_ILLEGAL_ARGUMENTS+String.valueOf(parameters)+GenericConstants.CLOSING_ROUND_BRACKET, e);
    } catch (final IllegalAccessException e) {
        throw new CCException.Error(PROBLEM_TO_ACCESS+classname+GenericConstants.HASH_DIESE+ amethodname + METHOD_ACCESS_RESTRICTION, e);
    } catch (final InvocationTargetException e) {
    throw new CCException.Error(PROBLEM_TO_ACCESS+classname+GenericConstants.HASH_DIESE+ amethodname + METHOD_INVOCATION_ISSUE, e);
    } 
    return res;
}

NumPy first and last element from array

How about:

In [10]: arr = numpy.array([1,23,4,6,7,8])

In [11]: [(arr[i], arr[-i-1]) for i in range(len(arr) // 2)]
Out[11]: [(1, 8), (23, 7), (4, 6)]

Depending on the size of arr, writing the entire thing in NumPy may be more performant:

In [41]: arr = numpy.array([1,23,4,6,7,8]*100)

In [42]: %timeit [(arr[i], arr[-i-1]) for i in range(len(arr) // 2)]
10000 loops, best of 3: 167 us per loop

In [43]: %timeit numpy.vstack((arr, arr[::-1]))[:,:len(arr)//2]
100000 loops, best of 3: 16.4 us per loop

LaTeX source code listing like in professional books

Have a try on the listings package. Here is an example of what I used some time ago to have a coloured Java listing:

\usepackage{listings}

[...]

\lstset{language=Java,captionpos=b,tabsize=3,frame=lines,keywordstyle=\color{blue},commentstyle=\color{darkgreen},stringstyle=\color{red},numbers=left,numberstyle=\tiny,numbersep=5pt,breaklines=true,showstringspaces=false,basicstyle=\footnotesize,emph={label}}

[...]

\begin{lstlisting}
public void here() {
    goes().the().code()
}

[...]

\end{lstlisting}

You may want to customize that. There are several references of the listings package. Just google them.

Create a txt file using batch file in a specific folder

This code written above worked for me as well. Although, you can use the code I am writing here:

@echo off

@echo>"d:\testing\dblank.txt

If you want to write some text to dblank.txt then add the following line in the end of your code

@echo Writing text to dblank.txt> dblank.txt

How do I copy an entire directory of files into an existing directory using Python?

Try This:

import os,shutil

def copydir(src, dst):
  h = os.getcwd()
  src = r"{}".format(src)
  if not os.path.isdir(dst):
     print("\n[!] No Such directory: ["+dst+"] !!!")
     exit(1)

  if not os.path.isdir(src):
     print("\n[!] No Such directory: ["+src+"] !!!")
     exit(1)
  if "\\" in src:
     c = "\\"
     tsrc = src.split("\\")[-1:][0]
  else:
    c = "/"
    tsrc = src.split("/")[-1:][0]

  os.chdir(dst)
  if os.path.isdir(tsrc):
    print("\n[!] The Directory Is already exists !!!")
    exit(1)
  try:
    os.mkdir(tsrc)
  except WindowsError:
    print("\n[!] Error: In[ {} ]\nPlease Check Your Dirctory Path !!!".format(src))
    exit(1)
  os.chdir(h)
  files = []
  for i in os.listdir(src):
    files.append(src+c+i)
  if len(files) > 0:
    for i in files:
        if not os.path.isdir(i):
            shutil.copy2(i, dst+c+tsrc)

  print("\n[*] Done ! :)")

copydir("c:\folder1", "c:\folder2")

Angular HTML binding

On [email protected]:

Html-Binding will not work when using an {{interpolation}}, use an "Expression" instead:

invalid

<p [innerHTML]="{{item.anleser}}"></p>

-> throws an error (Interpolation instead of expected Expression)

correct

<p [innerHTML]="item.anleser"></p>

-> this is the correct way.

you may add additional elements to the expression, like:

<p [innerHTML]="'<b>'+item.anleser+'</b>'"></p>

hint

HTML added using [innerHTML] (or added dynamically by other means like element.appenChild() or similar) won't be processed by Angular in any way except sanitization for security purposed.
Such things work only when the HTML is added statically to a components template. If you need this, you can create a component at runtime like explained in How can I use/create dynamic template to compile dynamic Component with Angular 2.0?

403 - Forbidden: Access is denied. ASP.Net MVC

I had the same issue (on windows server 2003), check in the IIS console if you have allowed ASP.NET v4 service extension (under IIS / ComputerName / Web Service extensions)

javax.net.ssl.SSLException: Received fatal alert: protocol_version

I ran into this issue while trying to install a PySpark package. I got around the issue by changing the TLS version with an environment variable:

echo 'export JAVA_TOOL_OPTIONS="-Dhttps.protocols=TLSv1.2"' >> ~/.bashrc
source ~/.bashrc

Build error, This project references NuGet

First I would check if your MusicKarma project has Microsoft.Net.Compilers in its packages.config file. If not then you could remove everything to do with that NuGet package from your MusicKarma.csproj.

If you are using the Microsoft.Net.Compilers NuGet package then my guess is that the path is incorrect. Looking at the directory name in the error message I would guess that the MusicKarma solution file (.sln) is in the same directory as the MusicKarma.csproj. If so then the packages directory is probably wrong since by default the packages directory would be inside the solution directory. So I am assuming that your packages directory is:

C:\Users\Bryan\Documents\Visual Studio 2015\Projects\MusicKarma\packages

Whilst your MusicKarma.csproj file is looking for the props file in:

C:\Users\Bryan\Documents\Visual Studio 2015\Projects\packages\Microsoft.Net.Compilers.1.1.1\build

So if that is the case then you can fix the problem by editing the path in your MusicKarma.csproj file or by reinstalling the NuGet package.

How can I add comments in MySQL?

You can use single line comments:

-- this is a comment
# this is also a comment

Or a multiline comment:

/*
   multiline
   comment
*/

Does Java have an exponential operator?

To do this with user input:

public static void getPow(){
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter first integer: ");    // 3
    int first = sc.nextInt();
    System.out.println("Enter second integer: ");    // 2
    int second = sc.nextInt();
    System.out.println(first + " to the power of " + second + " is " + 
        (int) Math.pow(first, second));    // outputs 9

What is the instanceof operator in JavaScript?

I think it's worth noting that instanceof is defined by the use of the "new" keyword when declaring the object. In the example from JonH;

var color1 = new String("green");
color1 instanceof String; // returns true
var color2 = "coral";
color2 instanceof String; // returns false (color2 is not a String object)

What he didn't mention is this;

var color1 = String("green");
color1 instanceof String; // returns false

Specifying "new" actually copied the end state of the String constructor function into the color1 var, rather than just setting it to the return value. I think this better shows what the new keyword does;

function Test(name){
    this.test = function(){
        return 'This will only work through the "new" keyword.';
    }
    return name;
}

var test = new Test('test');
test.test(); // returns 'This will only work through the "new" keyword.'
test // returns the instance object of the Test() function.

var test = Test('test');
test.test(); // throws TypeError: Object #<Test> has no method 'test'
test // returns 'test'

Using "new" assigns the value of "this" inside the function to the declared var, while not using it assigns the return value instead.

Android: how do I check if activity is running?

This is code for checking whether a particular service is running. I'm fairly sure it can work for an activity too as long as you change getRunningServices with getRunningAppProcesses() or getRunningTasks(). Have a look here http://developer.android.com/reference/android/app/ActivityManager.html#getRunningAppProcesses()

Change Constants.PACKAGE and Constants.BACKGROUND_SERVICE_CLASS accordingly

    public static boolean isServiceRunning(Context context) {

    Log.i(TAG, "Checking if service is running");

    ActivityManager activityManager = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);

    List<RunningServiceInfo> services = activityManager.getRunningServices(Integer.MAX_VALUE);

    boolean isServiceFound = false;

    for (int i = 0; i < services.size(); i++) {

        if (Constants.PACKAGE.equals(services.get(i).service.getPackageName())){

            if (Constants.BACKGROUND_SERVICE_CLASS.equals(services.get(i).service.getClassName())){
                isServiceFound = true;
            }
        }
    }

    Log.i(TAG, "Service was" + (isServiceFound ? "" : " not") + " running");

    return isServiceFound;

}

Using jQuery to center a DIV on the screen

This is untested, but something like this should work.

var myElement = $('#myElement');
myElement.css({
    position: 'absolute',
    left: '50%',
    'margin-left': 0 - (myElement.width() / 2)
});

How can I display a pdf document into a Webview?

String webviewurl = "http://test.com/testing.pdf";
webView.getSettings().setJavaScriptEnabled(true); 
if(webviewurl.contains(".pdf")){
    webviewurl = "http://docs.google.com/gview?embedded=true&url=" + webviewurl;        }
webview.loadUrl(webviewurl);

Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

Hello Thanks for the question; To resolve: "Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'"

In Windows Features check all for .NET 4 Advanced Services & .NET 3.5

enter image description here

Just like Nicolas Gago I tried aspnet_regiis.exe -iru but it didn't work. After the features were on then it yellow screen error was gone. Thanks;

SQL Server: Examples of PIVOTing String data

Well, for your sample and any with a limited number of unique columns, this should do it.

select 
    distinct a,
    (select distinct t2.b  from t t2  where t1.a=t2.a and t2.b='VIEW'),
    (select distinct t2.b from t t2  where t1.a=t2.a and t2.b='EDIT')
from t t1

Re-render React component when prop changes

You could use KEY unique key (combination of the data) that changes with props, and that component will be rerendered with updated props.

How to stop default link click behavior with jQuery

I've just wasted an hour on this. I tried everything - it turned out (and I can hardly believe this) that giving my cancel button and element id of cancel meant that any attempt to prevent event propagation would fail! I guess an HTML page must treat this as someone pressing ESC?

How to check if DST (Daylight Saving Time) is in effect, and if so, the offset?

This code uses the fact that getTimezoneOffset returns a greater value during Standard Time versus Daylight Saving Time (DST). Thus it determines the expected output during Standard Time, and it compares whether the output of the given date the same (Standard) or less (DST).

Note that getTimezoneOffset returns positive numbers of minutes for zones west of UTC, which are usually stated as negative hours (since they're "behind" UTC). For example, Los Angeles is UTC–8h Standard, UTC-7h DST. getTimezoneOffset returns 480 (positive 480 minutes) in December (winter, Standard Time), rather than -480. It returns negative numbers for the Eastern Hemisphere (such -600 for Sydney in winter, despite this being "ahead" (UTC+10h).

Date.prototype.stdTimezoneOffset = function () {
    var jan = new Date(this.getFullYear(), 0, 1);
    var jul = new Date(this.getFullYear(), 6, 1);
    return Math.max(jan.getTimezoneOffset(), jul.getTimezoneOffset());
}

Date.prototype.isDstObserved = function () {
    return this.getTimezoneOffset() < this.stdTimezoneOffset();
}

var today = new Date();
if (today.isDstObserved()) { 
    alert ("Daylight saving time!");
}

How to split/partition a dataset into training and test datasets for, e.g., cross validation?

There is another option that just entails using scikit-learn. As scikit's wiki describes, you can just use the following instructions:

from sklearn.model_selection import train_test_split

data, labels = np.arange(10).reshape((5, 2)), range(5)

data_train, data_test, labels_train, labels_test = train_test_split(data, labels, test_size=0.20, random_state=42)

This way you can keep in sync the labels for the data you're trying to split into training and test.

How to Count Duplicates in List with LINQ

You can use "group by" + "orderby". See LINQ 101 for details

var list = new List<string> {"a", "b", "a", "c", "a", "b"};
var q = from x in list
        group x by x into g
        let count = g.Count()
        orderby count descending
        select new {Value = g.Key, Count = count};
foreach (var x in q)
{
    Console.WriteLine("Value: " + x.Value + " Count: " + x.Count);
}

In response to this post (now deleted):

If you have a list of some custom objects then you need to use custom comparer or group by specific property.

Also query can't display result. Show us complete code to get a better help.

Based on your latest update:

You have this line of code:

group xx by xx into g

Since xx is a custom object system doesn't know how to compare one item against another. As I already wrote, you need to guide compiler and provide some property that will be used in objects comparison or provide custom comparer. Here is an example:

Note that I use Foo.Name as a key - i.e. objects will be grouped based on value of Name property.

There is one catch - you treat 2 objects to be duplicate based on their names, but what about Id ? In my example I just take Id of the first object in a group. If your objects have different Ids it can be a problem.

//Using extension methods
var q = list.GroupBy(x => x.Name)
            .Select(x => new {Count = x.Count(), 
                              Name = x.Key, 
                              ID = x.First().ID})
            .OrderByDescending(x => x.Count);

//Using LINQ
var q = from x in list
        group x by x.Name into g
        let count = g.Count()
        orderby count descending
        select new {Name = g.Key, Count = count, ID = g.First().ID};

foreach (var x in q)
{
    Console.WriteLine("Count: " + x.Count + " Name: " + x.Name + " ID: " + x.ID);
}

Displaying one div on top of another

There are many ways to do it, but this is pretty simple and avoids issues with disrupting inline content positioning. You might need to adjust for margins/padding, too.

#backdrop, #curtain {
  height: 100px;
  width: 200px;
}

#curtain {
  position: relative;
  top: -100px;
}

incompatible character encodings: ASCII-8BIT and UTF-8

I installed gem package mysql2.

gem install mysql2

and then I changed the adapter in mysql2 in database.yml.

PHP expects T_PAAMAYIM_NEKUDOTAYIM?

For me this happened within a class function.

In PHP 5.3 and above $this::$defaults worked fine; when I swapped the code into a server that for whatever reason had a lower version number it threw this error.

The solution, in my case, was to use the keyword self instead of $this:

self::$defaults works just fine.

If Radio Button is selected, perform validation on Checkboxes

Full validation example with javascript:

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Radio button: full validation example with javascript</title>
        <script>
            function send() {
                var genders = document.getElementsByName("gender");
                if (genders[0].checked == true) {
                    alert("Your gender is male");
                } else if (genders[1].checked == true) {
                    alert("Your gender is female");
                } else {
                    // no checked
                    var msg = '<span style="color:red;">You must select your gender!</span><br /><br />';
                    document.getElementById('msg').innerHTML = msg;
                    return false;
                }
                return true;
            }

            function reset_msg() {
                document.getElementById('msg').innerHTML = '';
            }
        </script>
    </head>
    <body>
        <form action="" method="POST">
            <label>Gender:</label>
            <br />
            <input type="radio" name="gender" value="m" onclick="reset_msg();" />Male
            <br />
            <input type="radio" name="gender" value="f" onclick="reset_msg();" />Female
            <br />
            <div id="msg"></div>
            <input type="submit" value="send>>" onclick="return send();" />
        </form>
    </body>
</html>

Regards,

Fernando

Instagram API: How to get all user media?

You're right, the Instagram API will only return 20 images per call. So you'll have to use the pagination feature.

If you're trying to use the API console. You'll want to first allow the API console to authenticate via your Instagram login. To do this you'll want to select OAUTH2 under the Authentication dropdown.

Once Authenticated, use the left hand side menu to select the users/{user-id}/media/recent endpoint. So for the sake of this post for {user-id} you can just replace it with self. This will then use your account to retrieve information.

At a bare minimum that is what's needed to do a GET for this endpoint. Once you send, you'll get some json returned to you. At the very top of the returned information after all the server info, you'll see a pagination portion with next_url and next_max_id.

next_max_id is what you'll use as a parameter for your query. Remember max_id is the id of the image that is the oldest of the 20 that was first returned. This will be used to return images earlier than this image.

You don't have to use the max_id if you don't want to. You can actually just grab the id of the image where you'd like to start querying more images from.

So from the returned data, copy the max_id into the parameter max_id. The request URL should look something like this https://api.instagram.com/v1/users/self/media/recent?max_id=XXXXXXXXXXX where XXXXXXXXXXX is the max_id. Hit send again and you should get the next 20 photos.

From there you'll also receive an updated max_id. You can then use that again to get the next set of 20 photos until eventually going through all of the user's photos.

What I've done in the project I'm working on is to load the first 20 photos returned from the initial recent media request. I then, assign the images with a data-id (-id can actually be whatever you'd like it to be). Then added a load more button on the bottom of the photo set.

When the button is clicked, I use jQuery to grab the last image and it's data-id attribute and use that to create a get call via ajax and append the results to the end of the photos already on the page. Instead of a button you could just replace it to have a infinite scrolling effect.

Hope that helps.