Programs & Examples On #Map projections

A map-projection transforms the coordinates of the spherical earth to a flat map in cartesian (x,y) space.

Difference between `Optional.orElse()` and `Optional.orElseGet()`

Short Answer:

  • orElse() will always call the given function whether you want it or not, regardless of Optional.isPresent() value
  • orElseGet() will only call the given function when the Optional.isPresent() == false

In real code, you might want to consider the second approach when the required resource is expensive to get.

// Always get heavy resource
getResource(resourceId).orElse(getHeavyResource()); 

// Get heavy resource when required.
getResource(resourceId).orElseGet(() -> getHeavyResource()) 

For more details, consider the following example with this function:

public Optional<String> findMyPhone(int phoneId)

The difference is as below:

                           X : buyNewExpensivePhone() called

+——————————————————————————————————————————————————————————————————+——————————————+
|           Optional.isPresent()                                   | true | false |
+——————————————————————————————————————————————————————————————————+——————————————+
| findMyPhone(int phoneId).orElse(buyNewExpensivePhone())          |   X  |   X   |
+——————————————————————————————————————————————————————————————————+——————————————+
| findMyPhone(int phoneId).orElseGet(() -> buyNewExpensivePhone()) |      |   X   |
+——————————————————————————————————————————————————————————————————+——————————————+

When optional.isPresent() == false, there is no difference between two ways. However, when optional.isPresent() == true, orElse() always calls the subsequent function whether you want it or not.

Finally, the test case used is as below:

Result:

------------- Scenario 1 - orElse() --------------------
  1.1. Optional.isPresent() == true (Redundant call)
    Going to a very far store to buy a new expensive phone
    Used phone: MyCheapPhone

  1.2. Optional.isPresent() == false
    Going to a very far store to buy a new expensive phone
    Used phone: NewExpensivePhone

------------- Scenario 2 - orElseGet() --------------------
  2.1. Optional.isPresent() == true
    Used phone: MyCheapPhone

  2.2. Optional.isPresent() == false
    Going to a very far store to buy a new expensive phone
    Used phone: NewExpensivePhone

Code:

public class TestOptional {
    public Optional<String> findMyPhone(int phoneId) {
        return phoneId == 10
                ? Optional.of("MyCheapPhone")
                : Optional.empty();
    }

    public String buyNewExpensivePhone() {
        System.out.println("\tGoing to a very far store to buy a new expensive phone");
        return "NewExpensivePhone";
    }


    public static void main(String[] args) {
        TestOptional test = new TestOptional();
        String phone;
        System.out.println("------------- Scenario 1 - orElse() --------------------");
        System.out.println("  1.1. Optional.isPresent() == true (Redundant call)");
        phone = test.findMyPhone(10).orElse(test.buyNewExpensivePhone());
        System.out.println("\tUsed phone: " + phone + "\n");

        System.out.println("  1.2. Optional.isPresent() == false");
        phone = test.findMyPhone(-1).orElse(test.buyNewExpensivePhone());
        System.out.println("\tUsed phone: " + phone + "\n");

        System.out.println("------------- Scenario 2 - orElseGet() --------------------");
        System.out.println("  2.1. Optional.isPresent() == true");
        // Can be written as test::buyNewExpensivePhone
        phone = test.findMyPhone(10).orElseGet(() -> test.buyNewExpensivePhone());
        System.out.println("\tUsed phone: " + phone + "\n");

        System.out.println("  2.2. Optional.isPresent() == false");
        phone = test.findMyPhone(-1).orElseGet(() -> test.buyNewExpensivePhone());
        System.out.println("\tUsed phone: " + phone + "\n");
    }
}

Function of Project > Clean in Eclipse

Its function depends on the builders that you have in your project (they can choose to interpret clean command however they like) and whether you have auto-build turned on. If auto-build is on, invoking clean is equivalent of a clean build. First artifacts are removed, then a full build is invoked. If auto-build is off, clean will remove the artifacts and stop. You can then invoke build manually later.

An existing connection was forcibly closed by the remote host - WCF

I have seen this once. Are the users requesting different amounts of data? I found that even if you can configure a binding for data payloads (i.e. maxReceivedMessageSize), the httpRuntime maxRequestLength trumps the WCF setting, so if IIS is trying to serve a request that exceeds that, it exhibits this behavior.

Think of it like this:

If maxReceivedMessageSize is 12MB in your WCF behavior, and maxRequestLength is 4MB (default), IIS wins.

Excel: Creating a dropdown using a list in another sheet?

That cannot be done in excel 2007. The list must be in the same sheet as your data. It might work in later versions though.

How to join on multiple columns in Pyspark?

An alternative approach would be:

df1 = sqlContext.createDataFrame(
    [(1, "a", 2.0), (2, "b", 3.0), (3, "c", 3.0)],
    ("x1", "x2", "x3"))

df2 = sqlContext.createDataFrame(
    [(1, "f", -1.0), (2, "b", 0.0)], ("x1", "x2", "x4"))

df = df1.join(df2, ['x1','x2'])
df.show()

which outputs:

+---+---+---+---+
| x1| x2| x3| x4|
+---+---+---+---+
|  2|  b|3.0|0.0|
+---+---+---+---+

With the main advantage being that the columns on which the tables are joined are not duplicated in the output, reducing the risk of encountering errors such as org.apache.spark.sql.AnalysisException: Reference 'x1' is ambiguous, could be: x1#50L, x1#57L.


Whenever the columns in the two tables have different names, (let's say in the example above, df2 has the columns y1, y2 and y4), you could use the following syntax:

df = df1.join(df2.withColumnRenamed('y1','x1').withColumnRenamed('y2','x2'), ['x1','x2'])

Ruby value of a hash key?

This question seems to be ambiguous.

I'll try with my interpretation of the request.

def do_something(data)
   puts "Found! #{data}"
end

a = { 'x' => 'test', 'y' => 'foo', 'z' => 'bar' }
a.each { |key,value| do_something(value) if key == 'x' }

This will loop over all the key,value pairs and do something only if the key is 'x'.

What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association

See here for an example from the OpenJPA docs. CascadeType.ALL means it will do all actions.

Quote:

CascadeType.PERSIST: When persisting an entity, also persist the entities held in its fields. We suggest a liberal application of this cascade rule, because if the EntityManager finds a field that references a new entity during the flush, and the field does not use CascadeType.PERSIST, it is an error.

CascadeType.REMOVE: When deleting an entity, it also deletes the entities held in this field.

CascadeType.REFRESH: When refreshing an entity, also refresh the entities held in this field.

CascadeType.MERGE: When merging entity state, also merge the entities held in this field.

Sebastian

Importing variables from another file?

In Python you can access the contents of other files like as if they
are some kind of a library, compared to other languages like java or any oop base languages , This is really cool ;

This makes accessing the contents of the file or import it to to process it or to do anything with it ; And that is the Main reason why Python is highly preferred Language for Data Science and Machine Learning etc. ;

And this is the picture of project structure This

Where I am accessing variables from .env file where the API links and Secret keys reside .

General Structure:

from <File-Name> import *

How to detect when a youtube video finishes playing?

This can be done through the youtube player API:

http://jsfiddle.net/7Gznb/

Working example:

    <div id="player"></div>

    <script src="http://www.youtube.com/player_api"></script>

    <script>

        // create youtube player
        var player;
        function onYouTubePlayerAPIReady() {
            player = new YT.Player('player', {
              width: '640',
              height: '390',
              videoId: '0Bmhjf0rKe8',
              events: {
                onReady: onPlayerReady,
                onStateChange: onPlayerStateChange
              }
            });
        }

        // autoplay video
        function onPlayerReady(event) {
            event.target.playVideo();
        }

        // when video ends
        function onPlayerStateChange(event) {        
            if(event.data === 0) {          
                alert('done');
            }
        }

    </script>

Maven dependencies are failing with a 501 error

Maven is moving to HTTPS and disabling HTTP access

Short story, from January 15, 2020, Maven Central repository is not longer supporting HTTP connections (other repositories are doing the same). Therefore, you will indicate your Maven/Gradle settings to use an HTTPS URL.

Solution:

You can choose one of the following three approaches.

  1. Add a repository in your project´s pom.xml file

    <project>
    ...
      <repositories>
        <repository>
          <id>central maven repo</id>
          <name>central maven repo https</name>
          <url>https://repo.maven.apache.org/maven2</url>
        </repository>
      </repositories>
    </project>
    
  2. Add the repository into a profile in the settings.xml file.

    <profile>
      <id>my profile</id>
      <repositories>
        <repository>
          <id>central maven repo</id>
          <name>central maven repo https</name>
          <url>https://repo.maven.apache.org/maven2</url>
          </repository>
      </repositories>
    </profile>
    
  3. Update you maven version to a new one that uses https values as default. The lastest one at this moment 3.6.3 Download here

For Gradle:

Only replace the URL for the HTTPS version.

repositories {
   maven { url "https://repo.maven.apache.org/maven2" }
}

Split a large dataframe into a list of data frames based on common value in column

You can just as easily access each element in the list using e.g. path[[1]]. You can't put a set of matrices into an atomic vector and access each element. A matrix is an atomic vector with dimension attributes. I would use the list structure returned by split, it's what it was designed for. Each list element can hold data of different types and sizes so it's very versatile and you can use *apply functions to further operate on each element in the list. Example below.

#  For reproducibile data
set.seed(1)

#  Make some data
userid <- rep(1:2,times=4)
data1 <- replicate(8 , paste( sample(letters , 3 ) , collapse = "" ) )
data2 <- sample(10,8)
df <- data.frame( userid , data1 , data2 )

#  Split on userid
out <- split( df , f = df$userid )
#$`1`
#  userid data1 data2
#1      1   gjn     3
#3      1   yqp     1
#5      1   rjs     6
#7      1   jtw     5

#$`2`
#  userid data1 data2
#2      2   xfv     4
#4      2   bfe    10
#6      2   mrx     2
#8      2   fqd     9

Access each element using the [[ operator like this:

out[[1]]
#  userid data1 data2
#1      1   gjn     3
#3      1   yqp     1
#5      1   rjs     6
#7      1   jtw     5

Or use an *apply function to do further operations on each list element. For instance, to take the mean of the data2 column you could use sapply like this:

sapply( out , function(x) mean( x$data2 ) )
#   1    2 
#3.75 6.25 

Adding Google Translate to a web site

{{-- Google Language Translator  START --}}
<style>
.google-translate {
    display: inline-block;
    vertical-align: top;
    padding-top: 15px;
}

.goog-logo-link {
    display: none !important;
}

.goog-te-gadget {
    color: transparent !important;
}

#google_translate_element {
    display: none;
}

.goog-te-banner-frame.skiptranslate {
    display: none !important;
}

body {
    top: 0px !important;
}

</style>

<script src="{{asset('js/translate-google.js')}}"></script>



<script type="text/javascript">
function googleTranslateElementInit2(){
    new google.translate.TranslateElement({
                    pageLanguage:'en',
                    includedLanguages: 'en,es',
        // https://ctrlq.org/code/19899-google-translate-languages
        // includedLanguages: 'en,it,la,fr',
        // layout:     google.translate.TranslateElement.InlineLayout.SIMPLE,
        autoDisplay:true
    },'google_translate_element2');
    var a = document.querySelector("#google_translate_element select");
    // console.log(a);

    if(a){
        a.selectedIndex=1;
        a.dispatchEvent(new Event('change'));
    }
}
</script>

<ul class="navbar-nav my-lg-0 m-r-10">
<li>
    <div class="google-translate">
        <div id="google_translate_element2"></div>
    </div>
</li>

{{-- Google Language Translator ENDS --}}

// translate-google.js
(function () {
var gtConstEvalStartTime = new Date();

function d(b) {
    var a = document.getElementsByTagName("head")[0];
    a || (a = document.body.parentNode.appendChild(document.createElement("head")));
    a.appendChild(b)
}

function _loadJs(b) {
    // console.log(b);
    var a = document.createElement("script");
    a.type = "text/javascript";
    a.charset = "UTF-8";
    a.src = b;
    d(a)
}

function _loadCss(b) {
    var a = document.createElement("link");
    a.type = "text/css";
    a.rel = "stylesheet";
    a.charset = "UTF-8";
    a.href = b;
    d(a)
}

function _isNS(b) {
    b = b.split(".");
    for (var a = window, c = 0; c < b.length; ++c)
        if (!(a = a[b[c]])) return !1;
    return !0
}

function _setupNS(b) {
    b = b.split(".");
    for (var a = window, c = 0; c < b.length; ++c) a.hasOwnProperty ? a.hasOwnProperty(b[c]) ? a = a[b[c]] : a = a[b[c]] = {} : a = a[b[c]] || (a[b[c]] = {});
    return a
}
window.addEventListener && "undefined" == typeof document.readyState && window.addEventListener("DOMContentLoaded", function () {
    document.readyState = "complete"
}, !1);
if (_isNS('google.translate.Element')) {
    return
}(function () {
    var c = _setupNS('google.translate._const');
    c._cest = gtConstEvalStartTime;
    gtConstEvalStartTime = undefined;
    c._cl = 'en';
    c._cuc = 'googleTranslateElementInit2';
    c._cac = '';
    c._cam = '';
    c._ctkk = eval('((function(){var a\x3d3002255536;var b\x3d-2533142796;return 425386+\x27.\x27+(a+b)})())');
    var h = 'translate.googleapis.com';
    var s = (true ? 'https' : window.location.protocol == 'https:' ? 'https' : 'http') + '://';
    var b = s + h;
    c._pah = h;
    c._pas = s;
    c._pbi = b + '/translate_static/img/te_bk.gif';
    c._pci = b + '/translate_static/img/te_ctrl3.gif';
    c._pli = b + '/translate_static/img/loading.gif';
    c._plla = h + '/translate_a/l';
    c._pmi = b + '/translate_static/img/mini_google.png';
    c._ps = b + '/translate_static/css/translateelement.css';
    c._puh = 'translate.google.com';
    _loadCss(c._ps);
    _loadJs(b + '/translate_static/js/element/main.js');
})();
})();

HTML.ActionLink vs Url.Action in ASP.NET Razor

Html.ActionLink generates an <a href=".."></a> tag automatically.

Url.Action generates only an url.

For example:

@Html.ActionLink("link text", "actionName", "controllerName", new { id = "<id>" }, null)

generates:

<a href="/controllerName/actionName/<id>">link text</a>

and

@Url.Action("actionName", "controllerName", new { id = "<id>" }) 

generates:

/controllerName/actionName/<id>

Best plus point which I like is using Url.Action(...)

You are creating anchor tag by your own where you can set your own linked text easily even with some other html tag.

<a href="@Url.Action("actionName", "controllerName", new { id = "<id>" })">

   <img src="<ImageUrl>" style"width:<somewidth>;height:<someheight> />

   @Html.DisplayFor(model => model.<SomeModelField>)
</a>

How do I access store state in React Redux?

Import connect from react-redux and use it to connect the component with the state connect(mapStates,mapDispatch)(component)

import React from "react";
import { connect } from "react-redux";


const MyComponent = (props) => {
    return (
      <div>
        <h1>{props.title}</h1>
      </div>
    );
  }
}

Finally you need to map the states to the props to access them with this.props

const mapStateToProps = state => {
  return {
    title: state.title
  };
};
export default connect(mapStateToProps)(MyComponent);

Only the states that you map will be accessible via props

Check out this answer: https://stackoverflow.com/a/36214059/4040563

For further reading : https://medium.com/@atomarranger/redux-mapstatetoprops-and-mapdispatchtoprops-shorthand-67d6cd78f132

.Net: How do I find the .NET version?

MSDN details it here very nicely on how to check it from registry:

To find .NET Framework versions by viewing the registry (.NET Framework 1-4)

  1. On the Start menu, choose Run.
  2. In the Open box, enter regedit.exe.You must have administrative credentials to run regedit.exe.
  3. In the Registry Editor, open the following subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP

The installed versions are listed under the NDP subkey. The version number is stored in the Version entry. For the .NET Framework 4 the Version entry is under the Client or Full subkey (under NDP), or under both subkeys.

To find .NET Framework versions by viewing the registry (.NET Framework 4.5 and later)

  1. On the Start menu, choose Run.
  2. In the Open box, enter regedit.exe. You must have administrative credentials to run regedit.exe.
  3. In the Registry Editor, open the following subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full

Note that the path to the Full subkey includes the subkey Net Framework rather than .NET Framework

Check for a DWORD value named Release. The existence of the Release DWORD indicates that the .NET Framework 4.5 or newer has been installed on that computer.

enter image description here

Note: The last row in the above snapshot which got clipped reads On all other OS versions: 461310. I tried my level best to avoid the information getting clipped while taking the screenshot but the table was way too big.

Get the Application Context In Fragment In Android?

Try to use getActivity(); This will solve your problem.

Remove all special characters except space from a string using JavaScript

The first solution does not work for any UTF-8 alphabet. (It will cut text such as ??????). I have managed to create a function which does not use RegExp and use good UTF-8 support in the JavaScript engine. The idea is simple if a symbol is equal in uppercase and lowercase it is a special character. The only exception is made for whitespace.

function removeSpecials(str) {
    var lower = str.toLowerCase();
    var upper = str.toUpperCase();

    var res = "";
    for(var i=0; i<lower.length; ++i) {
        if(lower[i] != upper[i] || lower[i].trim() === '')
            res += str[i];
    }
    return res;
}

Update: Please note, that this solution works only for languages where there are small and capital letters. In languages like Chinese, this won't work.

Update 2: I came to the original solution when I was working on a fuzzy search. If you also trying to remove special characters to implement search functionality, there is a better approach. Use any transliteration library which will produce you string only from Latin characters and then the simple Regexp will do all magic of removing special characters. (This will work for Chinese also and you also will receive side benefits by making Tromsø == Tromso).

Possible to extend types in Typescript?

May be below approach will be helpful for someone TS with reactjs

interface Event {
   name: string;
   dateCreated: string;
   type: string;
}

interface UserEvent<T> extends Event<T> {
    UserId: string;
}

How to write a multidimensional array to a text file?

You can simply traverse the array in three nested loops and write their values to your file. For reading, you simply use the same exact loop construction. You will get the values in exactly the right order to fill your arrays correctly again.

How to sort strings in JavaScript

In your operation in your initial question, you are performing the following operation:

item1.attr - item2.attr

So, assuming those are numbers (i.e. item1.attr = "1", item2.attr = "2") You still may use the "===" operator (or other strict evaluators) provided that you ensure type. The following should work:

return parseInt(item1.attr) - parseInt(item2.attr);

If they are alphaNumeric, then do use localCompare().

"code ." Not working in Command Line for Visual Studio Code on OSX/Mac

For that to work there needs to be an executable named 'code' in your bash path, which some installers add for you, but this one apparently did not. The best way to do this could be to add a symlink to the visual studio code app in your /usr/local/bin folder. You can do this by using a command like the following in your terminal.

ln -s "/Path/To/Visual Studio Code" "/usr/local/bin/code"

You will likely need to put sudo in front of that to have the permissions for it to complete successfully.

How to find if an array contains a string

I'm afraid I don't think there's a shortcut to do this - if only someone would write a linq wrapper for VB6!

You could write a function that does it by looping through the array and checking each entry - I don't think you'll get cleaner than that.

There's an example article that provides some details here: http://www.vb6.us/tutorials/searching-arrays-visual-basic-6

Google Maps API v3 adding an InfoWindow to each marker

Try this:

for (var i in tracks[racer_id].data.points) {
    values = tracks[racer_id].data.points[i];                
    point = new google.maps.LatLng(values.lat, values.lng);
    if (values.qst) {
        var marker = new google.maps.Marker({map: map, position: point, clickable: true});
        tracks[racer_id].markers[i] = marker;
        var info = new google.maps.InfoWindow({
            content: '<b>Speed:</b> ' + values.inst + ' knots'
        });
        tracks[racer_id].info[i] = info;
        google.maps.event.addListener(tracks[racer_id].markers[i], 'click', function() {
            tracks[racer_id].info[i].open(map, tracks[racer_id].markers[i]);
        });
    }
    track_coordinates.push(point);
    bd.extend(point);
}

How to display databases in Oracle 11g using SQL*Plus

SELECT NAME FROM v$database; shows the database name in oracle

Unfortunately Launcher3 has stopped working error in android studio?

  1. Press the Apps menu button on your Android mobile phone device. It will display icons of all the apps installed on your mobile phone device. Press Settings.

  2. Press Apps. (Pressing on Apps button will list down all the apps installed on your mobile phone.

  3. Browse the Apps list and press on the app called "Launcher 3". (Launcher 3 is an app and it will be listed in the App list whenever you access Settings > Apps in your android phone).

  4. Pressing on the "Launcher 3" app will open the "App info screen" which will show some details pertaining to that app. On this App info screen, you will find buttons like "Force Stop", "Uninstall", "Clear Data" and "Clear Cache" etc.

  5. In Android Marshmallow (i.e. Android 6.0) choose Settings > Apps > Launcher3 > STORAGE. Press "Clear Cache". If this fails, press "Clear data". This will eventually restore functionality, but all custom shortcuts will be lost.

Restart the phone and its done. All the home screens along with app shortcuts will appear again and your mobile phone is at your service again.

I hope it explains well on how to solve the launcher problem in Android. Worked for me.

c# why can't a nullable int be assigned null as a value

Another option is to use

int? accom = (accomStr == "noval" ? Convert.DBNull : Convert.ToInt32(accomStr); 

I like this one most.

JPA Hibernate One-to-One relationship

Try this

@Entity

@Table(name="tblperson")

public class Person {

public int id;

public OtherInfo otherInfo;
@Id //Here Id is autogenerated
@Column(name="id")
@GeneratedValue(strategy=GenerationType.AUTO)
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}

@OneToOne(cascade = CascadeType.ALL,targetEntity=OtherInfo.class)
@JoinColumn(name="otherInfo_id") //there should be a column otherInfo_id in Person
public OtherInfo getOtherInfo() {
    return otherInfo;
}
public void setOtherInfo(OtherInfo otherInfo) {
    this.otherInfo= otherInfo;
}
rest of attributes ...
}


@Entity

@Table(name="tblotherInfo")

public class OtherInfo {

private int id;

private Person person;

@Id

@Column(name="id")
@GeneratedValue(strategy=GenerationType.AUTO)
public Long getId() {
    return id;
}
public void setId(Long id) {
    this.id = id;
}

  @OneToOne(mappedBy="OtherInfo",targetEntity=Person.class)   
public College getPerson() {
    return person;
}
public void setPerson(Person person) {
    this.person = person;
}    
 rest of attributes ...
}

Possible reason for NGINX 499 error codes

Once I got 499 "Request has been forbidden by antivirus" as an AJAX http response (false positive by Kaspersky Internet Security with light heuristic analysis, deep heuristic analysis knew correctly there was nothing wrong).

Find all tables containing column with specified name - MS SQL Server

I don't know why so many of you suggesting Joining with sys.table with sys.columns you can simply use below code:

Select object_name(object_id) as TableName,* from SYS.columns where name LIKE '%MyName%'

or

If you want schema name as well:

Select * from  INFORMATION_SCHEMA.COLUMNS
where COLUMN_NAME LIKE '%MyName%'

Creating a node class in Java

Welcome to Java! This Nodes are like a blocks, they must be assembled to do amazing things! In this particular case, your nodes can represent a list, a linked list, You can see an example here:

public class ItemLinkedList {
    private ItemInfoNode head;
    private ItemInfoNode tail;
    private int size = 0;

    public int getSize() {
        return size;
    }

    public void addBack(ItemInfo info) {
        size++;
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, null, tail);
            this.tail.next =node;
            this.tail = node;
        }
    }

    public void addFront(ItemInfo info) {
        size++;
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, head, null);
            this.head.prev = node;
            this.head = node;
        }
    }

    public ItemInfo removeBack() {
        ItemInfo result = null;
        if (head != null) {
            size--;
            result = tail.info;
            if (tail.prev != null) {
                tail.prev.next = null;
                tail = tail.prev;
            } else {
                head = null;
                tail = null;
            }
        }
        return result;
    }

    public ItemInfo removeFront() {
        ItemInfo result = null;
        if (head != null) {
            size--;
            result = head.info;
            if (head.next != null) {
                head.next.prev = null;
                head = head.next;
            } else {
                head = null;
                tail = null;
            }
        }
        return result;
    }

    public class ItemInfoNode {

        private ItemInfoNode next;
        private ItemInfoNode prev;
        private ItemInfo info;

        public ItemInfoNode(ItemInfo info, ItemInfoNode next, ItemInfoNode prev) {
            this.info = info;
            this.next = next;
            this.prev = prev;
        }

        public void setInfo(ItemInfo info) {
            this.info = info;
        }

        public void setNext(ItemInfoNode node) {
            next = node;
        }

        public void setPrev(ItemInfoNode node) {
            prev = node;
        }

        public ItemInfo getInfo() {
            return info;
        }

        public ItemInfoNode getNext() {
            return next;
        }

        public ItemInfoNode getPrev() {
            return prev;
        }
    }
}

EDIT:

Declare ItemInfo as this:

public class ItemInfo {
    private String name;
    private String rfdNumber;
    private double price;
    private String originalPosition;

    public ItemInfo(){
    }

    public ItemInfo(String name, String rfdNumber, double price, String originalPosition) {
        this.name = name;
        this.rfdNumber = rfdNumber;
        this.price = price;
        this.originalPosition = originalPosition;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getRfdNumber() {
        return rfdNumber;
    }

    public void setRfdNumber(String rfdNumber) {
        this.rfdNumber = rfdNumber;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getOriginalPosition() {
        return originalPosition;
    }

    public void setOriginalPosition(String originalPosition) {
        this.originalPosition = originalPosition;
    }
}

Then, You can use your nodes inside the linked list like this:

public static void main(String[] args) {
    ItemLinkedList list = new ItemLinkedList();
    for (int i = 1; i <= 10; i++) {
        list.addBack(new ItemInfo("name-"+i, "rfd"+i, i, String.valueOf(i)));

    }
    while (list.size() > 0){
        System.out.println(list.removeFront().getName());
    }
}

Can (domain name) subdomains have an underscore "_" in it?

No, you can't use underscore in subdomain but hypen (dash). i.e my-subdomain.agahost.com is acceptable and my_subdomain.agahost.com would not be acceptable.

Nginx 403 forbidden for all files

I've tried different cases and only when owner was set to nginx (chown -R nginx:nginx "/var/www/myfolder") - it started to work as expected.

export html table to csv

There is a very easy free and open source solution at http://jordiburgos.com/post/2014/excellentexport-javascript-export-to-excel-csv.html

First download the javascript file and sample files from https://github.com/jmaister/excellentexport/releases/tag/v1.4

The html page looks like below.

Make sure the the javascript file is in the same folder or change the path of the script in the html file accordingly.

<html>
<head>
    <title>Export to excel test</title>
    <script src="excellentexport.js"></script>
    <style>
        table, tr, td {
            border: 1px black solid;
        }
    </style>
</head>
<body>
    <h1>ExcellentExport.js</h1>

    Check on <a href="http://jordiburgos.com">jordiburgos.com</a> and  <a href="https://github.com/jmaister/excellentexport">GitHub</a>.

    <h3>Test page</h3>

    <br/>

    <a download="somedata.xls" href="#" onclick="return ExcellentExport.excel(this, 'datatable', 'Sheet Name Here');">Export to Excel</a>
    <br/>

    <a download="somedata.csv" href="#" onclick="return ExcellentExport.csv(this, 'datatable');">Export to CSV</a>
    <br/>

    <table id="datatable">
        <tr>
            <th>Column 1</th>
            <th>Column "cool" 2</th>
            <th>Column 3</th>
        </tr>
        <tr>
            <td>100,111</td>
            <td>200</td>
            <td>300</td>
        </tr>
        <tr>
            <td>400</td>
            <td>500</td>
            <td>600</td>
        </tr>
        <tr>
            <td>Text</td>
            <td>More text</td>
            <td>Text with
                new line</td>
        </tr>
    </table>

</body>

It is very easy to use this as I have tried most of the other methods.

Java Date cut off time information

The question is contradictory. It asks for a date without a time of day yet displays an example with a time of 00:00:00.

Joda-Time

UPDATE: The Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes. See my other Answer for java.time solution.

If instead you want the time-of-day set to the first moment of the day, use a DateTime object on the Joda-Time library and call its withTimeAtStartOfDay method. Be aware that the first moment may not be the time 00:00:00 because of Daylight Saving Time or perhaps other anomalies.

How can I get a process handle by its name in C++?

OpenProcess Function

From MSDN:

To open a handle to another local process and obtain full access rights, you must enable the SeDebugPrivilege privilege.

Set Background cell color in PHPExcel

function cellColor($cells,$color){
    global $objPHPExcel;

    $objPHPExcel->getActiveSheet()->getStyle($cells)->getFill()->applyFromArray(array(
        'type' => PHPExcel_Style_Fill::FILL_SOLID,
        'startcolor' => array(
             'rgb' => $color
        )
    ));
}

cellColor('B5', 'F28A8C');
cellColor('G5', 'F28A8C');
cellColor('A7:I7', 'F28A8C');
cellColor('A17:I17', 'F28A8C');
cellColor('A30:Z30', 'F28A8C');

enter image description here

How do I insert values into a Map<K, V>?

Try this code

HashMap<String, String> map = new HashMap<String, String>();
map.put("EmpID", EmpID);
map.put("UnChecked", "1");

Get skin path in Magento?

First note that

Mage::getBaseDir('skin')

returns only path to skin directory of your Magento install (/your/magento/dir/skin).

You can access absolute path to currently used skin directory using:

Mage::getDesign()->getSkinBaseDir()

This method accepts an associative array as optional parameter to modify result.

Following keys are recognized:

  • _area frontend (default) or adminhtml
  • _package your package
  • _theme your theme
  • _relative when this is set (as an key) path relative to Mage::getBaseDir('skin') is returned.

So in your case correct answer would be:

require(Mage::getDesign()->getSkinBaseDir().DS.'myfunc.php');

Vertically and horizontally centering text in circle in CSS (like iphone notification badge)

Interesting question! While there are plenty of guides on horizontally and vertically centering a div, an authoritative treatment of the subject where the centered div is of an unpredetermined width is conspicuously absent.

Let's apply some basic constraints:

  • No Javascript
  • No mangling of the display property to table-cell, which is of questionable support status

Given this, my entry into the fray is the use of the inline-block display property to horizontally center the span within an absolutely positioned div of predetermined height, vertically centered within the parent container in the traditional top: 50%; margin-top: -123px fashion.

Markup: div > div > span

CSS:

body > div { position: relative; height: XYZ; width: XYZ; }
div > div { 
  position: absolute;
  top: 50%;
  height: 30px;
  margin-top: -15px; 
  text-align: center;}
div > span { display: inline-block; }

Source: http://jsfiddle.net/38EFb/


An alternate solution that doesn't require extraneous markups but that very likely produces more problems than it solves is to use the line-height property. Don't do this. But it is included here as an academic note: http://jsfiddle.net/gucwW/

How does Go update third-party packages?

The above answeres have the following problems:

  1. They update everything including your app (in case you have uncommitted changes).
  2. They updated packages you may have already removed from your project but are already on your disk.

To avoid these, do the following:

  1. Delete the 3rd party folders that you want to update.
  2. go to your app folder and run go get -d

String delimiter in string.split method

Pipe (|) is a special character in regex. to escape it, you need to prefix it with backslash (\). But in java, backslash is also an escape character. so again you need to escape it with another backslash. So your regex should be \\|\\| e.g, String[] tokens = myString.split("\\|\\|");

What does "|=" mean? (pipe equal operator)

Note: ||= does not exist. (logical or) You can use

y= y || expr; // expr is NOT evaluated if y==true

or

y = expr ? true : y;  // expr is always evaluated.

What is the garbage collector in Java?

It frees memory allocated to objects that are not being used by the program any more - hence the name "garbage". For example:

public static Object otherMethod(Object obj) {
    return new Object();
}

public static void main(String[] args) {
    Object myObj = new Object();
    myObj = otherMethod(myObj);
    // ... more code ...  
}

I know this is extremely contrived, but here after you call otherMethod() the original Object created is made unreachable - and that's "garbage" that gets garbage collected.

In Java the GC runs automatically, but you can also call it explicitly with System.gc() and try to force a major garbage collection. As Pascal Thivent points out, you really shouldn't have to do this and it might do more harm than good (see this question).

For more, see the wikipedia entry on Garbage collection and Tuning Garbage Collection (from Oracle)

How do I keep track of pip-installed packages in an Anaconda (Conda) environment?

conda-env now does this automatically (if pip was installed with conda).

You can see how this works by using the export tool used for migrating an environment:

conda env export -n <env-name> > environment.yml

The file will list both conda packages and pip packages:

name: stats
channels:
  - javascript
dependencies:
  - python=3.4
  - bokeh=0.9.2
  - numpy=1.9.*
  - nodejs=0.10.*
  - flask
  - pip:
    - Flask-Testing

If you're looking to follow through with exporting the environment, move environment.yml to the new host machine and run:

conda env create -f path/to/environment.yml

Interface or an Abstract Class: which one to use?

Why to use abstract classes? The following is a simple example. Lets say we have the following code:

<?php 

class Fruit {
    private $color;

    public function eat() {
        // chew
    }

    public function setColor($c) {
        $this->color = $c;
    }
}

class Apple extends Fruit {
    public function eat() {
        // chew until core
    }
}

class Orange extends Fruit {
    public function eat() {
        // peeling
        // chew
    }
}

Now I give you an apple and you eat it. What does it taste like? It tastes like an apple.

<?php 
$apple = new Apple();
$apple->eat();

// Now I give you a fruit.
$fruit = new Fruit();
$fruit->eat();

What does that taste like? Well, it doesn't make much sense, so you shouldn't be able to do that. This is accomplished by making the Fruit class abstract as well as the eat method inside of it.

<?php 
abstract class Fruit {
    private $color;

    abstract public function eat(){}

    public function setColor($c) {
        $this->color = $c;
    }
}
?>

An abstract class is just like an interface, but you can define methods in an abstract class whereas in an interface they are all abstract. Abstract classes can have both empty and working/concrete methods. In interfaces, functions defined there cannot have a body. In abstract classes, they can.

A real world example:

<?php 
abstract class person {

    public $LastName;
    public $FirstName;
    public $BirthDate;

    abstract protected function write_info();
}

final class employee extends person{

    public $EmployeeNumber;
    public $DateHired;

    public function write_info(){
        //sql codes here
        echo "Writing ". $this->LastName . "'s info to emloyee dbase table <br>";   
    }
}

final class student extends person{

    public $StudentNumber;
    public $CourseName;

    public function write_info(){
        //sql codes here
        echo "Writing ". $this->LastName . "'s info to student dbase table <br>";
    }
}

///----------
$personA = new employee;
$personB = new student;

$personA->FirstName="Joe";
$personA->LastName="Sbody";

$personB->FirstName="Ben";
$personB->LastName="Dover";

$personA->write_info();
// Writing Sbody's info to emloyee dbase table
$personB->write_info();
// Writing Dover's info to student dbase table 

Dynamically add properties to a existing object

If you have a class with an object property, or if your property actually casts to an object, you can reshape the object by reassigning its properties, as in:

  MyClass varClass = new MyClass();
  varClass.propObjectProperty = new { Id = 1, Description = "test" };

  //if you need to treat the class as an object
  var varObjectProperty = ((dynamic)varClass).propObjectProperty;
  ((dynamic)varClass).propObjectProperty = new { Id = varObjectProperty.Id, Description = varObjectProperty.Description, NewDynamicProperty = "new dynamic property description" };

  //if your property is an object, instead
  var varObjectProperty = varClass.propObjectProperty;
  varClass.propObjectProperty = new { Id = ((dynamic)varObjectProperty).Id, Description = ((dynamic)varObjectProperty).Description, NewDynamicProperty = "new dynamic property description" };

With this approach, you basically rewrite the object property adding or removing properties as if you were first creating the object with the

new { ... }

syntax.

In your particular case, you're probably better off creating an actual object to which you assign properties like "dob" and "address" as if it were a person, and at the end of the process, transfer the properties to the actual "Person" object.

How to pass parameters to ThreadStart method in Thread?

You can encapsulate the thread function(download) and the needed parameter(s)(filename) in a class and use the ThreadStart delegate to execute the thread function.

public class Download
{
    string _filename;

    Download(string filename)
    {
       _filename = filename;
    }

    public void download(string filename)
    {
       //download code
    }
}

Download = new Download(filename);
Thread thread = new Thread(new ThreadStart(Download.download);

Convert String to Carbon

Try this

$date = Carbon::parse(date_format($youttimestring,'d/m/Y H:i:s'));
echo $date;

Apache HttpClient Android (Gradle)

The accepted answer does not seem quite right to me. There is no point dragging a different version of HttpMime when one can depend on the same version of it.

compile group: 'org.apache.httpcomponents' , name: 'httpclient-android' , version: '4.3.5'
compile (group: 'org.apache.httpcomponents' , name: 'httpmime' , version: '4.3.5') {
    exclude module: 'org.apache.httpcomponents:httpclient'
}

Get resultset from oracle stored procedure

Oracle is not sql server. Try the following in SQL Developer

variable rc refcursor;
exec testproc(:rc2);
print rc2

PHP Composer update "cannot allocate memory" error (using Laravel 4)

Sometimes by self-updating composer it solves the problem

php composer.phar self-update

Cheers

Create Setup/MSI installer in Visual Studio 2017

You need to install this extension to Visual Studio 2017/2019 in order to get access to the Installer Projects.

According to the page:

This extension provides the same functionality that currently exists in Visual Studio 2015 for Visual Studio Installer projects. To use this extension, you can either open the Extensions and Updates dialog, select the online node, and search for "Visual Studio Installer Projects Extension," or you can download directly from this page.

Once you have finished installing the extension and restarted Visual Studio, you will be able to open existing Visual Studio Installer projects, or create new ones.

How to strip HTML tags from a string in SQL Server?

Here's an updated version of this function that incorporates the RedFilter answer (Pinal's original) with the LazyCoders additions and the goodeye typo corrections AND my own addition to handle in-line <STYLE> tags inside the HTML.

ALTER FUNCTION [dbo].[udf_StripHTML]
(
@HTMLText varchar(MAX)
)
RETURNS varchar(MAX)
AS
BEGIN
DECLARE @Start  int
DECLARE @End    int
DECLARE @Length int

-- Replace the HTML entity &amp; with the '&' character (this needs to be done first, as
-- '&' might be double encoded as '&amp;amp;')
SET @Start = CHARINDEX('&amp;', @HTMLText)
SET @End = @Start + 4
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, '&')
SET @Start = CHARINDEX('&amp;', @HTMLText)
SET @End = @Start + 4
SET @Length = (@End - @Start) + 1
END

-- Replace the HTML entity &lt; with the '<' character
SET @Start = CHARINDEX('&lt;', @HTMLText)
SET @End = @Start + 3
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, '<')
SET @Start = CHARINDEX('&lt;', @HTMLText)
SET @End = @Start + 3
SET @Length = (@End - @Start) + 1
END

-- Replace the HTML entity &gt; with the '>' character
SET @Start = CHARINDEX('&gt;', @HTMLText)
SET @End = @Start + 3
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, '>')
SET @Start = CHARINDEX('&gt;', @HTMLText)
SET @End = @Start + 3
SET @Length = (@End - @Start) + 1
END

-- Replace the HTML entity &amp; with the '&' character
SET @Start = CHARINDEX('&amp;amp;', @HTMLText)
SET @End = @Start + 4
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, '&')
SET @Start = CHARINDEX('&amp;amp;', @HTMLText)
SET @End = @Start + 4
SET @Length = (@End - @Start) + 1
END

-- Replace the HTML entity &nbsp; with the ' ' character
SET @Start = CHARINDEX('&nbsp;', @HTMLText)
SET @End = @Start + 5
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, ' ')
SET @Start = CHARINDEX('&nbsp;', @HTMLText)
SET @End = @Start + 5
SET @Length = (@End - @Start) + 1
END

-- Replace any <br> tags with a newline
SET @Start = CHARINDEX('<br>', @HTMLText)
SET @End = @Start + 3
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, CHAR(13) + CHAR(10))
SET @Start = CHARINDEX('<br>', @HTMLText)
SET @End = @Start + 3
SET @Length = (@End - @Start) + 1
END

-- Replace any <br/> tags with a newline
SET @Start = CHARINDEX('<br/>', @HTMLText)
SET @End = @Start + 4
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, CHAR(13) + CHAR(10))
SET @Start = CHARINDEX('<br/>', @HTMLText)
SET @End = @Start + 4
SET @Length = (@End - @Start) + 1
END

-- Replace any <br /> tags with a newline
SET @Start = CHARINDEX('<br />', @HTMLText)
SET @End = @Start + 5
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, CHAR(13) + CHAR(10))
SET @Start = CHARINDEX('<br />', @HTMLText)
SET @End = @Start + 5
SET @Length = (@End - @Start) + 1
END

-- Remove anything between <STYLE> tags
SET @Start = CHARINDEX('<STYLE', @HTMLText)
SET @End = CHARINDEX('</STYLE>', @HTMLText, CHARINDEX('<', @HTMLText)) + 7
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, '')
SET @Start = CHARINDEX('<STYLE', @HTMLText)
SET @End = CHARINDEX('</STYLE>', @HTMLText, CHARINDEX('</STYLE>', @HTMLText)) + 7
SET @Length = (@End - @Start) + 1
END

-- Remove anything between <whatever> tags
SET @Start = CHARINDEX('<', @HTMLText)
SET @End = CHARINDEX('>', @HTMLText, CHARINDEX('<', @HTMLText))
SET @Length = (@End - @Start) + 1

WHILE (@Start > 0 AND @End > 0 AND @Length > 0) BEGIN
SET @HTMLText = STUFF(@HTMLText, @Start, @Length, '')
SET @Start = CHARINDEX('<', @HTMLText)
SET @End = CHARINDEX('>', @HTMLText, CHARINDEX('<', @HTMLText))
SET @Length = (@End - @Start) + 1
END

RETURN LTRIM(RTRIM(@HTMLText))

END

jQuery Multiple ID selectors

You can use multiple id's the way you wrote:

$('#upload_link, #upload_link2, #upload_link3')

However, that doesn't mean that those ids exist within the DOM when you've executed your code. It also doesn't mean that upload is a legitimate function. It also doesn't mean that upload has been built in a way that allows for multiple elements in a selection.

upload is a custom jQuery plugin, so you'll have to show what's going on with upload for us to be able to help you.

SQL Case Sensitive String Compare

Just as another alternative you could use HASHBYTES, something like this:

SELECT * 
FROM a_table 
WHERE HASHBYTES('sha1', attribute) = HASHBYTES('sha1', 'k')

Python "SyntaxError: Non-ASCII character '\xe2' in file"

I got this error for characters in my comments (from copying/pasting content from the web into my editor for note-taking purposes).

To resolve in Text Wrangler:

  1. Highlight the text
  2. Go the the Text menu
  3. Select "Convert to ASCII"

link_to method and click event in Rails

To follow up on Ron's answer if using JQuery and putting it in application.js or the head section you need to wrap it in a ready() section...

$(document).ready(function() {
  $('#my-link').click(function(event){
    alert('Hooray!');
    event.preventDefault(); // Prevent link from following its href
  });
});

add new element in laravel collection object

If you want to add item to the beginning of the collection you can use prepend:

$item->prepend($product, 'key');

How do I loop through a date range?

you can use this.

 DateTime dt0 = new DateTime(2009, 3, 10);
 DateTime dt1 = new DateTime(2009, 3, 26);

 for (; dt0.Date <= dt1.Date; dt0=dt0.AddDays(3))
 {
    //Console.WriteLine(dt0.Date.ToString("yyyy-MM-dd"));
    //take action
 }

Determining Referer in PHP

Using $_SERVER['HTTP_REFERER']

The address of the page (if any) which referred the user agent to the current page. This is set by the user agent. Not all user agents will set this, and some provide the ability to modify HTTP_REFERER as a feature. In short, it cannot really be trusted.

if (!empty($_SERVER['HTTP_REFERER'])) {
    header("Location: " . $_SERVER['HTTP_REFERER']);
} else {
    header("Location: index.php");
}
exit;

Update rows in one table with data from another table based on one column in each being equal

It's not an insert if the record already exists in t1 (the user_id matches) unless you are happy to create duplicate user_id's.

You might want an update?

UPDATE t1
   SET <t1.col_list> = (SELECT <t2.col_list>
                          FROM t2
                         WHERE t2.user_id = t1.user_id)
 WHERE EXISTS
      (SELECT 1
         FROM t2
        WHERE t1.user_id = t2.user_id);

Hope it helps...

Bootstrap: How do I identify the Bootstrap version?

You can also check the bootstrap version via the javascript console in the browser:

$.fn.tooltip.Constructor.VERSION // => "3.3.7"

Credit: https://stackoverflow.com/a/43233731/1608226

Posting this here because I always come across this question when I forget to include JavaScript in the search and wind up on this question instead of the one above. If this helps you, be sure to upvote that answer as well.

Note: For older versions of bootstrap (less than 3 or so), you'll proably need to search the page's JavaScript or CSS files for the bootstrap version. Just came across this on an app using bootstrap 2.3.2. In this case, the (current) top answer is likely the correct one, you'll need to search the source code for the bootstrap find what version it uses. (Added 9/18/2020, though was in comment since 8/13/2020)

Creating an IFRAME using JavaScript

It is better to process HTML as a template than to build nodes via JavaScript (HTML is not XML after all.) You can keep your IFRAME's HTML syntax clean by using a template and then appending the template's contents into another DIV.

<div id="placeholder"></div>

<script id="iframeTemplate" type="text/html">
    <iframe src="...">
        <!-- replace this line with alternate content -->
    </iframe>
</script>

<script type="text/javascript">
var element,
    html,
    template;

element = document.getElementById("placeholder");
template = document.getElementById("iframeTemplate");
html = template.innerHTML;

element.innerHTML = html;
</script>

How to find the socket buffer size of linux

For getting the buffer size in c/c++ program the following is the flow

int n;
unsigned int m = sizeof(n);
int fdsocket;
fdsocket = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP); // example
getsockopt(fdsocket,SOL_SOCKET,SO_RCVBUF,(void *)&n, &m);
// now the variable n will have the socket size

How to scroll page in flutter

you can scroll any part of content in two ways ...

  1. you can use the list view directly
  2. or SingleChildScrollView

most of the time i use List view directly when ever there is a keybord intraction in that specific screen so that the content dont get overlap by the keyboard and more over scrolls to top ....

this trick will be helpful many a times....

What is ".NET Core"?

.NET Core is an open source and cross platform version of .NET Framework.

Check if enum exists in Java

You can also use Guava and do something like this:

// This method returns enum for a given string if it exists, otherwise it returns default enum.
private MyEnum getMyEnum(String enumName) {
  // It is better to return default instance of enum instead of null
  return hasMyEnum(enumName) ? MyEnum.valueOf(enumName) : MyEnum.DEFAULT;
}

// This method checks that enum for a given string exists.
private boolean hasMyEnum(String enumName) {
  return Iterables.any(Arrays.asList(MyEnum.values()), new Predicate<MyEnum>() {
    public boolean apply(MyEnum myEnum) {
      return myEnum.name().equals(enumName);
    }
  }); 
}

In second method I use guava (Google Guava) library which provides very useful Iterables class. Using the Iterables.any() method we can check if a given value exists in a list object. This method needs two parameters: a list and Predicate object. First I used Arrays.asList() method to create a list with all enums. After that I created new Predicate object which is used to check if a given element (enum in our case) satisfies the condition in apply method. If that happens, method Iterables.any() returns true value.

Vertical rulers in Visual Studio Code

Visual Studio Code 0.10.10 introduced this feature. To configure it, go to menu FilePreferencesSettings and add this to to your user or workspace settings:

"editor.rulers": [80,120]

The color of the rulers can be customized like this:

"workbench.colorCustomizations": {
    "editorRuler.foreground": "#ff4081"
}

ImageView in circular through xml

also, these two libraries can help you.

https://github.com/vinc3m1/RoundedImageView

implement below code:

implementation 'com.makeramen:roundedimageview:2.3.0'

Simple Usage:

<com.makeramen.roundedimageview.RoundedImageView
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/imageView1"
        android:src="@drawable/photo1"
        android:scaleType="fitCenter"
        app:riv_corner_radius="30dip"
        app:riv_border_width="2dip"
        app:riv_border_color="#333333"
        app:riv_mutate_background="true"
        app:riv_tile_mode="repeat"
        app:riv_oval="true" />

https://github.com/chirag-kachhadiya/RoundedImageView

Simple Usage:

implement below code:

implementation 'com.github.chirag-kachhadiya:RoundedImageView:1.0'



 <com.infinityandroid.roundedimageview.RoundedImageView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:layout_margin="10dp"
                android:adjustViewBounds="true"
                android:src="@drawable/the_hundred"
                app:corner_radius="10" />

Avoid printStackTrace(); use a logger call instead

Let's talk in from company concept. Log gives you flexible levels (see Difference between logger.info and logger.debug). Different people want to see different levels, like QAs, developers, business people. But e.printStackTrace() will print out everything. Also, like if this method will be restful called, this same error may print several times. Then the Devops or Tech-Ops people in your company may be crazy because they will receive the same error reminders. I think a better replacement could be log.error("errors happend in XXX", e) This will also print out whole information which is easy reading than e.printStackTrace()

How to draw lines in Java

A very simple example of a swing component to draw lines. It keeps internally a list with the lines that have been added with the method addLine. Each time a new line is added, repaint is invoked to inform the graphical subsytem that a new paint is required.

The class also includes some example of usage.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.LinkedList;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class LinesComponent extends JComponent{

private static class Line{
    final int x1; 
    final int y1;
    final int x2;
    final int y2;   
    final Color color;

    public Line(int x1, int y1, int x2, int y2, Color color) {
        this.x1 = x1;
        this.y1 = y1;
        this.x2 = x2;
        this.y2 = y2;
        this.color = color;
    }               
}

private final LinkedList<Line> lines = new LinkedList<Line>();

public void addLine(int x1, int x2, int x3, int x4) {
    addLine(x1, x2, x3, x4, Color.black);
}

public void addLine(int x1, int x2, int x3, int x4, Color color) {
    lines.add(new Line(x1,x2,x3,x4, color));        
    repaint();
}

public void clearLines() {
    lines.clear();
    repaint();
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    for (Line line : lines) {
        g.setColor(line.color);
        g.drawLine(line.x1, line.y1, line.x2, line.y2);
    }
}

public static void main(String[] args) {
    JFrame testFrame = new JFrame();
    testFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    final LinesComponent comp = new LinesComponent();
    comp.setPreferredSize(new Dimension(320, 200));
    testFrame.getContentPane().add(comp, BorderLayout.CENTER);
    JPanel buttonsPanel = new JPanel();
    JButton newLineButton = new JButton("New Line");
    JButton clearButton = new JButton("Clear");
    buttonsPanel.add(newLineButton);
    buttonsPanel.add(clearButton);
    testFrame.getContentPane().add(buttonsPanel, BorderLayout.SOUTH);
    newLineButton.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            int x1 = (int) (Math.random()*320);
            int x2 = (int) (Math.random()*320);
            int y1 = (int) (Math.random()*200);
            int y2 = (int) (Math.random()*200);
            Color randomColor = new Color((float)Math.random(), (float)Math.random(), (float)Math.random());
            comp.addLine(x1, y1, x2, y2, randomColor);
        }
    });
    clearButton.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            comp.clearLines();
        }
    });
    testFrame.pack();
    testFrame.setVisible(true);
}

}

Android: How to add R.raw to project?

Adding a raw folder to your resource folder (/res/) should do the trick.

Read more here: https://developer.android.com/guide/topics/resources/providing-resources.html

error: resource android:attr/fontVariationSettings not found

I have soled the problem by changing target android version to 28 in project.properties (target=android-28) and installed cordova-plugin-androidx and cordova-plugin-androidx-adapter.

How to set the thumbnail image on HTML5 video?

1) add the below jquery:

$thumbnail.on('click', function(e){
 e.preventDefault();
 src = src+'&autoplay=1'; // src: the original URL for embedding 
 $videoContainer.empty().append( $iframe.clone().attr({'src': src}) ); // $iframe: the original iframe for embedding
 }
);

note: in the first src (shown) add the original youtube link.

2) edit the iframe tag as:

<iframe width="1280" height="720" src="https://www.youtube.com/embed/nfQHF87vY0s?autoplay=1" frameborder="0" allowfullscreen></iframe>

note: copy paste the youtube video id after the embed/ in the iframe src.

print memory address of Python variable

id is the method you want to use: to convert it to hex:

hex(id(variable_here))

For instance:

x = 4
print hex(id(x))

Gave me:

0x9cf10c

Which is what you want, right?

(Fun fact, binding two variables to the same int may result in the same memory address being used.)
Try:

x = 4
y = 4
w = 9999
v = 9999
a = 12345678
b = 12345678
print hex(id(x))
print hex(id(y))
print hex(id(w))
print hex(id(v))
print hex(id(a))
print hex(id(b))

This gave me identical pairs, even for the large integers.

How to use Oracle's LISTAGG function with a unique filter?

I don't have an 11g instance available today but could you not use:

SELECT group_id,
       LISTAGG(name, ',') WITHIN GROUP (ORDER BY name) AS names
  FROM (
       SELECT UNIQUE
              group_id,
              name
         FROM demotable
       )
 GROUP BY group_id

Inserting data to table (mysqli insert)

Okay, of course the question has been answered, but no-one seems to notice the third line of your code. It continuosly bugged me.

    <?php
    mysqli_connect("localhost","root","","web_table");
    mysql_select_db("web_table") or die(mysql_error());

for some reason, you made a mysqli connection to server, but you are trying to make a mysql connection to database.To get going, rather use

       $link = mysqli_connect("localhost","root","","web_table");
       mysqli_select_db ($link , "web_table" ) or die.....

or for where i began

     <?php $connection = mysqli_connect("localhost","root","","web_table");       
      global $connection; // global connection to databases - kill it once you're done

or just query with a $connection parameter as the other argument like above. Get rid of that third line.

ASP.NET MVC3 Razor - Html.ActionLink style

VB sample:

 @Html.ActionLink("Home", "Index", Nothing, New With {.style = "font-weight:bold;", .class = "someClass"})

Sample Css:

.someClass
{
    color: Green !important;
}

In my case, I found that I need the !important attribute to over ride the site.css a:link css class

How do I "commit" changes in a git submodule?

$ git submodule status --recursive

Is also a life saver in this situation. You can use it and gitk --all to keep track of your sha1's and verify your sub-modules are pointing at what you think they are.

validate natural input number with ngpattern

<label>Mobile Number(*)</label>
<input id="txtMobile" ng-maxlength="10" maxlength="10" Validate-phone  required  name='strMobileNo' ng-model="formModel.strMobileNo" type="text"  placeholder="Enter Mobile Number">
<span style="color:red" ng-show="regForm.strMobileNo.$dirty && regForm.strMobileNo.$invalid"><span ng-show="regForm.strMobileNo.$error.required">Phone is required.</span>

the following code will help for phone number validation and the respected directive is

app.directive('validatePhone', function() {
var PHONE_REGEXP = /^[789]\d{9}$/;
  return {
    link: function(scope, elm) {
      elm.on("keyup",function(){
            var isMatchRegex = PHONE_REGEXP.test(elm.val());
            if( isMatchRegex&& elm.hasClass('warning') || elm.val() == ''){
              elm.removeClass('warning');
            }else if(isMatchRegex == false && !elm.hasClass('warning')){
              elm.addClass('warning');
            }
      });
    }
  }
});

Iterating over all the keys of a map

https://play.golang.org/p/JGZ7mN0-U-

for k, v := range m { 
    fmt.Printf("key[%s] value[%s]\n", k, v)
}

or

for k := range m {
    fmt.Printf("key[%s] value[%s]\n", k, m[k])
}

Go language specs for for statements specifies that the first value is the key, the second variable is the value, but doesn't have to be present.

How to use new PasswordEncoder from Spring Security

Having just gone round the internet to read up on this and the options in Spring I'd second Luke's answer, use BCrypt (it's mentioned in the source code at Spring).

The best resource I found to explain why to hash/salt and why use BCrypt is a good choice is here: Salted Password Hashing - Doing it Right.

Why use 'virtual' for class properties in Entity Framework model definitions?

We can't talk about virtual members without referring to polymorphism. In fact, a function, property, indexer or event in a base class marked as virtual will allow override from a derived class.

By default, members of a class are non-virtual and cannot be marked as that if static, abstract, private, or override modifiers.

Example Let's consider the ToString() method in System.Object. Because this method is a member of System.Object it's inherited in all classes and will provide the ToString() methods to all of them.

namespace VirtualMembersArticle
{
    public class Company
    {
        public string Name { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Company company = new Company() { Name = "Microsoft" };
            Console.WriteLine($"{company.ToString()}");
            Console.ReadLine();
        }   
    }
}

The output of the previous code is:

VirtualMembersArticle.Company

Let's consider that we want to change the standard behavior of the ToString() methods inherited from System.Object in our Company class. To achieve this goal it's enough to use the override keyword to declare another implementation of that method.

public class Company
{
    ...
    public override string ToString()
    {
        return $"Name: {this.Name}";
    }         
}

Now, when a virtual method is invoked, the run-time will check for an overriding member in its derived class and will call it if present. The output of our application will then be:

Name: Microsoft

In fact, if you check the System.Object class you will find that the method is marked as virtual.

namespace System
{
    [NullableContextAttribute(2)]
    public class Object
    {
        ....
        public virtual string? ToString();
        ....
    }
}

Could not find tools.jar. Please check that C:\Program Files\Java\jre1.8.0_151 contains a valid JDK installation

In Eclipse

Right click Project --> Java Build Path --> Libraries

  1. Remove the JRE
  2. Click on Add Library --> JRE System Library -->Next -->Alternate JRE --> installed JRE --> Add JDK and select and Apply

How to make a select with array contains value clause in psql

SELECT * FROM table WHERE arr && '{s}'::text[];

Compare two arrays for containment.

android: how to use getApplication and getApplicationContext from non activity / service class

The getApplication() method is located in the Activity class, so whenever you want getApplication() in a non activity class you have to pass an Activity instance to the constructor of that non activity class.

assume that test is my non activity class:

Test test = new Test(this);

In that class i have created one constructor:

 public Class Test
 {
    public Activity activity;
    public Test (Activity act)
    {
         this.activity = act;
         // Now here you can get getApplication()
    }
 }

What does the function then() mean in JavaScript?

Here is a thing I made for myself to clear out how things work. I guess others too can find this concrete example useful:

_x000D_
_x000D_
doit().then(function() { log('Now finally done!') });_x000D_
log('---- But notice where this ends up!');_x000D_
_x000D_
// For pedagogical reasons I originally wrote the following doit()-function so that _x000D_
// it was clear that it is a promise. That way wasn't really a normal way to do _x000D_
// it though, and therefore Slikts edited my answer. I therefore now want to remind _x000D_
// you here that the return value of the following function is a promise, because _x000D_
// it is an async function (every async function returns a promise). _x000D_
async function doit() {_x000D_
  log('Calling someTimeConsumingThing');_x000D_
  await someTimeConsumingThing();_x000D_
  log('Ready with someTimeConsumingThing');_x000D_
}_x000D_
_x000D_
function someTimeConsumingThing() {_x000D_
  return new Promise(function(resolve,reject) {_x000D_
    setTimeout(resolve, 2000);_x000D_
  })_x000D_
}_x000D_
_x000D_
function log(txt) {_x000D_
  document.getElementById('msg').innerHTML += txt + '<br>'_x000D_
}
_x000D_
<div id='msg'></div>
_x000D_
_x000D_
_x000D_

java.lang.Exception: No runnable methods exception in running JUnits

In Eclipse, I had to use New > Other > JUnit > Junit Test. A Java class created with the exact same text gave me the error, perhaps because it was using JUnit 3.x.

How to get the seconds since epoch from the time + date output of gmtime()?

ep = datetime.datetime(1970,1,1,0,0,0)
x = (datetime.datetime.utcnow()- ep).total_seconds()

This should be different from int(time.time()), but it is safe to use something like x % (60*60*24)

datetime — Basic date and time types:

Unlike the time module, the datetime module does not support leap seconds.

Set width to match constraints in ConstraintLayout

match_parent is not supported by ConstraintLayout. Set width to 0dp to let it match constraints.

Convert PEM to PPK file format

I had the same issue with PuttyGen not wanting to import an openSSH private key. I tried everything and what I found out was the old version of PuttyGen did not support importing OpenSSH. Once I downloaded the latest Putty, puttygen then allowed it to import the openssh private key just fine. I now have a hole in the side of my desk for pounding my head against it for the past hour.

Rmi connection refused with localhost

had a simliar problem with that connection exception. it is thrown either when the registry is not started yet (like in your case) or when the registry is already unexported (like in my case).

but a short comment to the difference between the 2 ways to start the registry:

Runtime.getRuntime().exec("rmiregistry 2020");

runs the rmiregistry.exe in javas bin-directory in a new process and continues parallel with your java code.

LocateRegistry.createRegistry(2020);

the rmi method call starts the registry, returns the reference to that registry remote object and then continues with the next statement.

in your case the registry is not started in time when you try to bind your object

How do I provide a username and password when running "git clone [email protected]"?

This is an excellent Stack Overflow question, and the answers have been very instructive, such that I was able to resolve an annoying problem I ran into recently.

The organization that I work for uses Atlassian's BitBucket product (not Github), essentially their version of GitHub so that repositories can be secured completely on premise. I was running into a similar problem as @coordinate, in that my password was required for a new repository I checked out. My credentials had been saved globally for all BitBucket projects, so I'm not sure what prompted the loss of credentials.

In short, I was able to enter the following GIT command (supplying only my username), which then prompted Git's Credential Manager to prompt me for the password, which I was then able to save.

git clone https://[email protected]/git/[organization]/[team]/[repository.git]

NOTE: the bracketed directory sub-paths simply refer to internal references, and will vary for you!

Difference between <? super T> and <? extends T> in Java

I'd like to visualize the difference. Suppose we have:

class A { }
class B extends A { }
class C extends B { }

List<? extends T> - reading and assigning:

|-------------------------|-------------------|---------------------------------|
|         wildcard        |        get        |              assign             |
|-------------------------|-------------------|---------------------------------|
|    List<? extends C>    |    A    B    C    |                       List<C>   |
|-------------------------|-------------------|---------------------------------|
|    List<? extends B>    |    A    B         |             List<B>   List<C>   |
|-------------------------|-------------------|---------------------------------|
|    List<? extends A>    |    A              |   List<A>   List<B>   List<C>   |
|-------------------------|-------------------|---------------------------------|

List<? super T> - writing and assigning:

|-------------------------|-------------------|-------------------------------------------|
|         wildcard        |        add        |                   assign                  |
|-------------------------|-------------------|-------------------------------------------|
|     List<? super C>     |              C    |  List<Object>  List<A>  List<B>  List<C>  |
|-------------------------|-------------------|-------------------------------------------|
|     List<? super B>     |         B    C    |  List<Object>  List<A>  List<B>           |
|-------------------------|-------------------|-------------------------------------------|
|     List<? super A>     |    A    B    C    |  List<Object>  List<A>                    |
|-------------------------|-------------------|-------------------------------------------|

In all of the cases:

  • you can always get Object from a list regardless of the wildcard.
  • you can always add null to a mutable list regardless of the wildcard.

Creating a LINQ select from multiple tables

If the anonymous type causes trouble for you, you can create a simple data class:

public class PermissionsAndPages
{
     public ObjectPermissions Permissions {get;set}
     public Pages Pages {get;set}
}

and then in your query:

select new PermissionsAndPages { Permissions = op, Page = pg };

Then you can pass this around:

return queryResult.SingleOrDefault(); // as PermissionsAndPages

throwing an exception in objective-c/cocoa

@throw([NSException exceptionWith…])

Xcode recognizes @throw statements as function exit points, like return statements. Using the @throw syntax avoids erroneous "Control may reach end of non-void function" warnings that you may get from [NSException raise:…].

Also, @throw can be used to throw objects that are not of class NSException.

Detect if string contains any spaces

What you have will find a space anywhere in the string, not just between words.

If you want to find any kind of whitespace, you can use this, which uses a regular expression:

if (/\s/.test(str)) {
    // It has any kind of whitespace
}

\s means "any whitespace character" (spaces, tabs, vertical tabs, formfeeds, line breaks, etc.), and will find that character anywhere in the string.

According to MDN, \s is equivalent to: [ \f\n\r\t\v?\u00a0\u1680?\u180e\u2000?\u2001\u2002?\u2003\u2004?\u2005\u2006?\u2007\u2008?\u2009\u200a?\u2028\u2029??\u202f\u205f?\u3000].


For some reason, I originally read your question as "How do I see if a string contains only spaces?" and so I answered with the below. But as @CrazyTrain points out, that's not what the question says. I'll leave it, though, just in case...

If you mean literally spaces, a regex can do it:

if (/^ *$/.test(str)) {
    // It has only spaces, or is empty
}

That says: Match the beginning of the string (^) followed by zero or more space characters followed by the end of the string ($). Change the * to a + if you don't want to match an empty string.

If you mean whitespace as a general concept:

if (/^\s*$/.test(str)) {
    // It has only whitespace
}

That uses \s (whitespace) rather than the space, but is otherwise the same. (And again, change * to + if you don't want to match an empty string.)

Creating a copy of an object in C#

The easiest way to do this is writing a copy constructor in the MyClass class.

Something like this:

namespace Example
{
    class MyClass
    {
        public int val;

        public MyClass()
        {
        }

        public MyClass(MyClass other)
        {
            val = other.val;
        }
    }
}

The second constructor simply accepts a parameter of his own type (the one you want to copy) and creates a new object assigned with the same value

class Program
{
    static void Main(string[] args)
    {
        MyClass objectA = new MyClass();
        MyClass objectB = new MyClass(objectA);
        objectA.val = 10;
        objectB.val = 20;
        Console.WriteLine("objectA.val = {0}", objectA.val);
        Console.WriteLine("objectB.val = {0}", objectB.val);
        Console.ReadKey();
    }
}

output:

objectA.val = 10

objectB.val = 20               

Load local JSON file into variable

For the given json format as in file ~/my-app/src/db/abc.json:

  [
      {
        "name":"Ankit",
        "id":1
      },
      {
        "name":"Aditi",
        "id":2
      },
      {
        "name":"Avani",
        "id":3
      }
  ]

inorder to import to .js file like ~/my-app/src/app.js:

 const json = require("./db/abc.json");

 class Arena extends React.Component{
   render(){
     return(
       json.map((user)=>
        {
          return(
            <div>{user.name}</div>
          )
        }
       )
      }
    );
   }
 }

 export default Arena;

Output:

Ankit Aditi Avani

How to check if cursor exists (open status)

Just Small change to what Gary W mentioned, adding 'SELECT':

IF (SELECT CURSOR_STATUS('global','myCursor')) >= -1
BEGIN
 DEALLOCATE myCursor
END

http://social.msdn.microsoft.com/Forums/en/sqlgetstarted/thread/eb268010-75fd-4c04-9fe8-0bc33ccf9357

How to get terminal's Character Encoding

To see the current locale information use locale command. Below is an example on RHEL 7.8

[usr@host ~]$ locale
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

how to count the total number of lines in a text file using python

You can use sum() with a generator expression:

with open('data.txt') as f:
    print sum(1 for _ in f)

Note that you cannot use len(f), since f is an iterator. _ is a special variable name for throwaway variables, see What is the purpose of the single underscore "_" variable in Python?.

You can use len(f.readlines()), but this will create an additional list in memory, which won't even work on huge files that don't fit in memory.

How to stop the Timer in android?

I had a similar problem: every time I push a particular button, I create a new Timer.

my_timer = new Timer("MY_TIMER");
my_timer.schedule(new TimerTask() {
...
}

Exiting from that activity I deleted the timer:

if(my_timer!=null){
my_timer.cancel();
my_timer = null;
}

But it was not enough because the cancel() method only canceled the latest Timer. The older ones were ignored an didn't stop running. The purge() method was not useful for me. I solved the problem just checking the Timer instantiation:

if(my_timer == null){
my_timer = new Timer("MY_TIMER");
my_timer.schedule(new TimerTask() {
...
}
}

Get records of current month

Try this query:

SELECT *
FROM table 
WHERE MONTH(FROM_UNIXTIME(columnName))= MONTH(CURDATE())

PHP mail function doesn't complete sending of e-mail

It may be a problem with "From:" $email address in this part of the $headers:

From: \"$name\" <$email>

To try it out, send an email without the headers part, like:

mail('[email protected]', $subject, $message); 

If that is a case, try using an email account that is already created at the system you are trying to send mail from.

How to use continue in jQuery each() loop?

We can break the $.each() loop at a particular iteration by making the callback function return false. Returning non-false is the same as a continue statement in a for loop; it will skip immediately to the next iteration. -- jQuery.each() | jQuery API Documentation

Effective method to hide email from spam bots

I have a completely different take on this. I use MailHide for this.

MailHide is a system from Google whereby the user needs to complete a reCAPTCHA test to then reveal the email to them.

SQL Server IIF vs CASE

IIF is a non-standard T-SQL function. It was added to SQL SERVER 2012, so that Access could migrate to SQL Server without refactoring the IIF's to CASE before hand. Once the Access db is fully migrated into SQL Server, you can refactor.

How to dump a dict to a json file?

Combine the answer of @mgilson and @gnibbler, I found what I need was this:


d = {"name":"interpolator",
     "children":[{'name':key,"size":value} for key,value in sample.items()]}
j = json.dumps(d, indent=4)
f = open('sample.json', 'w')
print >> f, j
f.close()

It this way, I got a pretty-print json file. The tricks print >> f, j is found from here: http://www.anthonydebarros.com/2012/03/11/generate-json-from-sql-using-python/

How can I cast int to enum?

You can use an extension method.

public static class Extensions
{

    public static T ToEnum<T>(this string data) where T : struct
    {
        if (!Enum.TryParse(data, true, out T enumVariable))
        {
            if (Enum.IsDefined(typeof(T), enumVariable))
            {
                return enumVariable;
            }
        }

        return default;
    }

    public static T ToEnum<T>(this int data) where T : struct
    {
        return (T)Enum.ToObject(typeof(T), data);
    }
}

Use it like the below code:

Enum:

public enum DaysOfWeeks
{
    Monday = 1,
    Tuesday = 2,
    Wednesday = 3,
    Thursday = 4,
    Friday = 5,
    Saturday = 6,
    Sunday = 7,
}

Usage:

 string Monday = "Mon";
 int Wednesday = 3;
 var Mon = Monday.ToEnum<DaysOfWeeks>();
 var Wed = Wednesday.ToEnum<DaysOfWeeks>();

Cannot serve WCF services in IIS on Windows 8

For Windows Server 2012, the solution is very similar to faester's (see above). From the Server Manager, click on Add roles and features, select the appropriate server, then select Features. Under .NET Framework 4.5 Features, you'll see WCF Services, and under that, you'll find HTTP Activation.

How to get week number of the month from the date in sql server 2008

You can simply get week number by getting minimum week number of month and deduct it from week number. Suppose you have a table with dates

select
    emp_id, dt , datepart(wk,dt) - (select min(datepart(wk,dt))
from
    workdates ) + 1 from workdates

Addition for BigDecimal

BigDecimal demo = new BigDecimal(15);

It is immutable beacuse it internally store you input i.e (15) as final private final BigInteger intVal; and same concept use at the time of string creation every input finally store in private final char value[];.So there is no implmented bug.

How do I convert a datetime to date?

Answer updated to Python 3.7 and more

Here is how you can turn a date-and-time object

(aka datetime.datetime object, the one that is stored inside models.DateTimeField django model field)

into a date object (aka datetime.date object):

from datetime import datetime

#your date-and-time object
# let's supposed it is defined as
datetime_element = datetime(2020, 7, 10, 12, 56, 54, 324893)

# where
# datetime_element = datetime(year, month, day, hour, minute, second, milliseconds)

# WHAT YOU WANT: your date-only object
date_element = datetime_element.date()

And just to be clear, if you print those elements, here is the output :

print(datetime_element)

2020-07-10 12:56:54.324893


print(date_element)

2020-07-10

Cannot find or open the PDB file in Visual Studio C++ 2010

If you have more as one Project in your Project Map use THE SAME hard coded PathFile PDB Name in all your Sub-Projects:

Use e.g.

D:\Visual Studio Projects\my_app\MyFile.pdb

Dont use e.g.

$(IntDir)\MyFile.pdb

in all the Sub-Projects !!!

= Compiler Param /Fd

Best way to do a PHP switch with multiple values per case?

Version 1 is certainly easier on the eyes, clearer as to your intentions, and easier to add case-conditions to.

I've never tried the second version. In many languages, this wouldn't even compile because each case labels has to evaluate to a constant-expression.

Convert ASCII TO UTF-8 Encoding

Using iconv looks like best solution but i my case I have Notice form this function: "Detected an illegal character in input string in" (without igonore). I use 2 functions to manipulate ASCII strings convert it to array of ASCII code and then serialize:

public static function ToAscii($string) {
    $strlen = strlen($string);
    $charCode = array();
    for ($i = 0; $i < $strlen; $i++) {
        $charCode[] = ord(substr($string, $i, 1));
    }
    $result = json_encode($charCode);
    return $result;
}

public static function fromAscii($string) {
    $charCode = json_decode($string);
    $result = '';
    foreach ($charCode as $code) {
        $result .= chr($code);
    };
    return $result;
}

How to form tuple column from two columns in Pandas

In [10]: df
Out[10]:
          A         B       lat      long
0  1.428987  0.614405  0.484370 -0.628298
1 -0.485747  0.275096  0.497116  1.047605
2  0.822527  0.340689  2.120676 -2.436831
3  0.384719 -0.042070  1.426703 -0.634355
4 -0.937442  2.520756 -1.662615 -1.377490
5 -0.154816  0.617671 -0.090484 -0.191906
6 -0.705177 -1.086138 -0.629708  1.332853
7  0.637496 -0.643773 -0.492668 -0.777344
8  1.109497 -0.610165  0.260325  2.533383
9 -1.224584  0.117668  1.304369 -0.152561

In [11]: df['lat_long'] = df[['lat', 'long']].apply(tuple, axis=1)

In [12]: df
Out[12]:
          A         B       lat      long                             lat_long
0  1.428987  0.614405  0.484370 -0.628298      (0.484370195967, -0.6282975278)
1 -0.485747  0.275096  0.497116  1.047605      (0.497115615839, 1.04760475074)
2  0.822527  0.340689  2.120676 -2.436831      (2.12067574274, -2.43683074367)
3  0.384719 -0.042070  1.426703 -0.634355      (1.42670326172, -0.63435462504)
4 -0.937442  2.520756 -1.662615 -1.377490     (-1.66261469102, -1.37749004179)
5 -0.154816  0.617671 -0.090484 -0.191906  (-0.0904840623396, -0.191905582481)
6 -0.705177 -1.086138 -0.629708  1.332853     (-0.629707821728, 1.33285348929)
7  0.637496 -0.643773 -0.492668 -0.777344   (-0.492667604075, -0.777344111021)
8  1.109497 -0.610165  0.260325  2.533383        (0.26032456699, 2.5333825651)
9 -1.224584  0.117668  1.304369 -0.152561     (1.30436900612, -0.152560909725)

Keyboard shortcut to comment lines in Sublime Text 2

you need to replace "/" with "7", it works on non english keyboard layout.

Is it possible to access an SQLite database from JavaScript?

You could use SQL.js which is the SQLlite lib compiled to JavaScript and store the database in the local storage introduced in HTML5.

Add CSS class to a div in code behind

What if:

 <asp:Button ID="Button1" runat="server" CssClass="test1 test3 test-test" />

To add or remove a class, instead of overwriting all classes with

   BtnventCss.CssClass = "hom_but_a"

keep the HTML correct:

    string classname = "TestClass";

    // Add a class
    BtnventCss.CssClass = String.Join(" ", Button1
               .CssClass
               .Split(' ')
               .Except(new string[]{"",classname})
               .Concat(new string[]{classname})
               .ToArray()
       );

     // Remove a class
     BtnventCss.CssClass = String.Join(" ", Button1
               .CssClass
               .Split(' ')
               .Except(new string[]{"",classname})
               .ToArray()
       );

This assures

  • The original classnames remain.
  • There are no double classnames
  • There are no disturbing extra spaces

Especially when client-side development is using several classnames on one element.

In your example, use

   string classname = "TestClass";

    // Add a class
    Button1.Attributes.Add("class", String.Join(" ", Button1
               .Attributes["class"]
               .Split(' ')
               .Except(new string[]{"",classname})
               .Concat(new string[]{classname})
               .ToArray()
       ));

     // Remove a class
     Button1.Attributes.Add("class", String.Join(" ", Button1
               .Attributes["class"]
               .Split(' ')
               .Except(new string[]{"",classname})
               .ToArray()
       ));

You should wrap this in a method/property ;)

How do I run Selenium in Xvfb?

open a terminal and run this command xhost +. This commands needs to be run every time you restart your machine. If everything works fine may be you can add this to startup commands

Also make sure in your /etc/environment file there is a line

export DISPLAY=:0.0 

And then, run your tests to see if your issue is resolved.

All please note the comment from sardathrion below before using this.

Default value of 'boolean' and 'Boolean' in Java

Boolean is an Object. So if it's an instance variable it will be null. If it's declared within a method you will have to initialize it, or there will be a compiler error.

If you declare as a primitive i.e. boolean. The value will be false by default if it's an instance variable (or class variable). If it's declared within a method you will still have to initialize it to either true or false, or there will be a compiler error.

ipad safari: disable scrolling, and bounce effect?

overflow: scroll;
-webkit-overflow-scrolling: touch;

On container you can set bounce effect inside element

Source: http://www.kylejlarson.com/blog/2011/fixed-elements-and-scrolling-divs-in-ios-5/

TypeError: a bytes-like object is required, not 'str' in python and CSV

file = open('parsed_data.txt', 'w')
for link in soup.findAll('a', attrs={'href': re.compile("^http")}): print (link)
soup_link = str(link)
print (soup_link)
file.write(soup_link)
file.flush()
file.close()

In my case, I used BeautifulSoup to write a .txt with Python 3.x. It had the same issue. Just as @tsduteba said, change the 'wb' in the first line to 'w'.

Closing a file after File.Create

The function returns a FileStream object. So you could use it's return value to open your StreamWriter or close it using the proper method of the object:

File.Create(myPath).Close();

Box-Shadow on the left side of the element only

box-shadow: -15px 0px 17px -7px rgba(0,0,0,0.75);

The first px value is the "Horizontal Length" set to -15px to position the shadow towards the left, the next px value is set to 0 so the shadow top and bottom is centred to minimise the top and bottom shadow.

The third value(17px) is known as the blur radius. The higher the number, the more blurred the shadow will be. And then last px value -7px is The spread radius, a positive value increases the size of the shadow, a negative value decreases the size of the shadow, at -7px it keeps the shadow from appearing above and below the item.

reference: CSS Box Shadow Property

How do you add a JToken to an JObject?

I think you're getting confused about what can hold what in JSON.Net.

  • A JToken is a generic representation of a JSON value of any kind. It could be a string, object, array, property, etc.
  • A JProperty is a single JToken value paired with a name. It can only be added to a JObject, and its value cannot be another JProperty.
  • A JObject is a collection of JProperties. It cannot hold any other kind of JToken directly.

In your code, you are attempting to add a JObject (the one containing the "banana" data) to a JProperty ("orange") which already has a value (a JObject containing {"colour":"orange","size":"large"}). As you saw, this will result in an error.

What you really want to do is add a JProperty called "banana" to the JObject which contains the other fruit JProperties. Here is the revised code:

JObject foodJsonObj = JObject.Parse(jsonText);
JObject fruits = foodJsonObj["food"]["fruit"] as JObject;
fruits.Add("banana", JObject.Parse(@"{""colour"":""yellow"",""size"":""medium""}"));

How to reload the current route with the angular 2 router

Angular 2-4 route reload hack

For me, using this method inside a root component (component, which is present on any route) works:

onRefresh() {
  this.router.routeReuseStrategy.shouldReuseRoute = function(){return false;};

  let currentUrl = this.router.url + '?';

  this.router.navigateByUrl(currentUrl)
    .then(() => {
      this.router.navigated = false;
      this.router.navigate([this.router.url]);
    });
  }

How is OAuth 2 different from OAuth 1?

OAuth 2.0 signatures are not required for the actual API calls once the token has been generated. It has only one security token.

OAuth 1.0 requires client to send two security tokens for each API call, and use both to generate the signature. It requires the protected resources endpoints have access to the client credentials in order to validate the request.

Here describes the difference between OAuth 1.0 and 2.0 and how both work.

How to change status bar color in Flutter?

It can be achieved in 2 steps:

  1. Set the status bar color to match to your page background using FlutterStatusbarcolor package
  2. Set the status bar buttons' (battery, wifi etc.) colors using the AppBar.brightness property

If you have an AppBar:

  @override
  Widget build(BuildContext context) {
    FlutterStatusbarcolor.setStatusBarColor(Colors.white);
    return Scaffold(
      appBar: AppBar(
        brightness: Brightness.light,
        // Other AppBar properties
      ),
      body: Container()
    );
  }

If you don't want to show the app bar in the page:

  @override
  Widget build(BuildContext context) {
    FlutterStatusbarcolor.setStatusBarColor(Colors.white);
    return Scaffold(
      appBar: AppBar(
        brightness: Brightness.light,
        elevation: 0.0,
        toolbarHeight: 0.0, // Hide the AppBar
      ),
      body: Container()
  }

Convert UTC to local time in Rails 3

If you're actually doing it just because you want to get the user's timezone then all you have to do is change your timezone in you config/applications.rb.

Like this:

Rails, by default, will save your time record in UTC even if you specify the current timezone.

config.time_zone = "Singapore"

So this is all you have to do and you're good to go.

How to remove all ListBox items?

I made on this way, and work properly to me:

if (listview1.Items.Count > 0)
        {
            for (int a = listview1.Items.Count -1; a > 0 ; a--)
            {
                listview1.Items.RemoveAt(a);
            }
                listview1.Refresh();

        }

Explaining: using "Clear()" erases only the items, do not removes then from object, using RemoveAt() to removing an item of beginning position just realocate the others [if u remove item[0], item[1] turns into [0] triggering a new internal event], so removing from the ending no affect de others position, its a Stack behavior, this way we can Stack over all items, reseting the object.

Where can I find a list of Mac virtual key codes?

Here are the all keycodes.

Here is a table with some keycodes for the three platforms. It is based on a US Extended keyboard layout.

http://web.archive.org/web/20100501161453/http://www.classicteck.com/rbarticles/mackeyboard.php

Or, there is an app in the Mac App Store named "Key Codes". Download it to see the keycodes of the keys you press.

Key Codes:
https://itunes.apple.com/tr/app/key-codes/id414568915?l=tr&mt=12

Angular-Material DateTime Picker Component?

You can have a datetime picker when using matInput with type datetime-local like so:

  <mat-form-field>
    <input matInput type="datetime-local" placeholder="start date">
  </mat-form-field>

You can click on each part of the placeholder to set the day, month, year, hours,minutes and whether its AM or PM.

How to use LogonUser properly to impersonate domain user from workgroup client

I have been successfull at impersonating users in another domain, but only with a trust set up between the 2 domains.

var token = IntPtr.Zero;
var result = LogonUser(userID, domain, password, LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, ref token);
if (result)
{
    return WindowsIdentity.Impersonate(token);
}

Is it not possible to define multiple constructors in Python?

Unlike Java, you cannot define multiple constructors. However, you can define a default value if one is not passed.

def __init__(self, city="Berlin"):
  self.city = city

HttpClient 4.0.1 - how to release connection?

I'm chiming in with a detailed answer that specifically addresses Apache HttpClient 4.0.1. I'm using this HttpClient version, since it's provided by WAS v8.0, and I need to use that provided HttpClient within Apache Wink v1.1.1, also provided by WAS v8.0, to make some NTLM-authenticated REST calls to Sharepoint.

To quote Oleg Kalnichevski on the Apache HttpClient mailing list:

Pretty much all this code is not necessary. (1) HttpClient will automatically release the underlying connection as long as the entity content is consumed to the end of stream; (2) HttpClient will automatically release the underlying connection on any I/O exception thrown while reading the response content. No special processing is required in such as case.

In fact, this is perfectly sufficient to ensure proper release of resources:

HttpResponse rsp = httpclient.execute(target, req); 
HttpEntity entity = rsp.getEntity(); 
if (entity != null) {
     InputStream instream = entity.getContent();
     try {
         // process content
     } finally {
         instream.close();
         // entity.consumeContent() would also do
     } 
}

That is it.

Source

PHP mySQL - Insert new record into table with auto-increment on primary key

You can also use blank single quotes for the auto_increment column. something like this. It worked for me.

$query = "INSERT INTO myTable VALUES ('','Fname', 'Lname', 'Website')";

Merge or combine by rownames

Not perfect but close:

newcol<-sapply(rownames(t), function(rn){z[match(rn, rownames(z)), 5]})
cbind(data.frame(t), newcol)

Error in plot.window(...) : need finite 'xlim' values

This error appears when the column contains character, if you check the data type it would be of type 'chr' converting the column to 'Factor' would solve this issue.

For e.g. In case you plot 'City' against 'Sales', you have to convert column 'City' to type 'Factor'

Redirect to new Page in AngularJS using $location

this worked for me inside a directive and works without refreshing the baseurl (just adds the endpoint).Good for Single Page Apps with routing mechanism.

  $(location).attr('href', 'http://localhost:10005/#/endpoint') 

Why is it string.join(list) instead of list.join(string)?

Both are not nice.

string.join(xs, delimit) means that the string module is aware of the existence of a list, which it has no business knowing about, since the string module only works with strings.

list.join(delimit) is a bit nicer because we're so used to strings being a fundamental type(and lingually speaking, they are). However this means that join needs to be dispatched dynamically because in the arbitrary context of a.split("\n") the python compiler might not know what a is, and will need to look it up(analogously to vtable lookup), which is expensive if you do it a lot of times.

if the python runtime compiler knows that list is a built in module, it can skip the dynamic lookup and encode the intent into the bytecode directly, whereas otherwise it needs to dynamically resolve "join" of "a", which may be up several layers of inheritence per call(since between calls, the meaning of join may have changed, because python is a dynamic language).

sadly, this is the ultimate flaw of abstraction; no matter what abstraction you choose, your abstraction will only make sense in the context of the problem you're trying to solve, and as such you can never have a consistent abstraction that doesn't become inconsistent with underlying ideologies as you start gluing them together without wrapping them in a view that is consistent with your ideology. Knowing this, python's approach is more flexible since it's cheaper, it's up to you to pay more to make it look "nicer", either by making your own wrapper, or your own preprocessor.

Why do package names often begin with "com"

It's just a namespace definition to avoid collision of class names. The com.domain.package.Class is an established Java convention wherein the namespace is qualified with the company domain in reverse.

How to move screen without moving cursor in Vim?

I'm surprised no one is using the Scrolloff option which keeps the cursor in the middle of the page. Try it with:

:set so=999

It's the first recommended method on the Vim wiki and works well.

How to create a temporary directory?

Use mktemp -d. It creates a temporary directory with a random name and makes sure that file doesn't already exist. You need to remember to delete the directory after using it though.

Writing data to a local text file with javascript

Our HTML:

<div id="addnew">
    <input type="text" id="id">
    <input type="text" id="content">
    <input type="button" value="Add" id="submit">
</div>

<div id="check">
    <input type="text" id="input">
    <input type="button" value="Search" id="search">
</div>

JS (writing to the txt file):

function writeToFile(d1, d2){
    var fso = new ActiveXObject("Scripting.FileSystemObject");
    var fh = fso.OpenTextFile("data.txt", 8, false, 0);
    fh.WriteLine(d1 + ',' + d2);
    fh.Close();
}
var submit = document.getElementById("submit");
submit.onclick = function () {
    var id      = document.getElementById("id").value;
    var content = document.getElementById("content").value;
    writeToFile(id, content);
}

checking a particular row:

function readFile(){
    var fso = new ActiveXObject("Scripting.FileSystemObject");
    var fh = fso.OpenTextFile("data.txt", 1, false, 0);
    var lines = "";
    while (!fh.AtEndOfStream) {
        lines += fh.ReadLine() + "\r";
    }
    fh.Close();
    return lines;
}
var search = document.getElementById("search");
search.onclick = function () {
    var input   = document.getElementById("input").value;
    if (input != "") {
        var text    = readFile();
        var lines   = text.split("\r");
        lines.pop();
        var result;
        for (var i = 0; i < lines.length; i++) {
            if (lines[i].match(new RegExp(input))) {
                result = "Found: " + lines[i].split(",")[1];
            }
        }
        if (result) { alert(result); }
        else { alert(input + " not found!"); }
    }
}

Put these inside a .hta file and run it. Tested on W7, IE11. It's working. Also if you want me to explain what's going on, say so.

.htaccess rewrite subdomain to directory

Try putting this in your .htaccess file:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^sub.domain.com
RewriteRule ^(.*)$ /subdomains/sub/$1 [L,NC,QSA]

For a more general rule (that works with any subdomain, not just sub) replace the last two lines with this:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com
RewriteRule ^(.*)$ subdomains/%1/$1 [L,NC,QSA]

Passing an array as a function parameter in JavaScript

you can use spread operator in a more basic form

[].concat(...array)

in the case of functions that return arrays but are expected to pass as arguments

Example:

function expectArguments(...args){
  return [].concat(...args);
}

JSON.stringify(expectArguments(1,2,3)) === JSON.stringify(expectArguments([1,2,3]))

how to fire event on file select

You could subscribe for the onchange event on the input field:

<input type="file" id="file" name="file" />

and then:

document.getElementById('file').onchange = function() {
    // fire the upload here
};

Test if registry value exists

This works for me:

Function Test-RegistryValue 
{
    param($regkey, $name)
    $exists = Get-ItemProperty "$regkey\$name" -ErrorAction SilentlyContinue
    Write-Host "Test-RegistryValue: $exists"
    if (($exists -eq $null) -or ($exists.Length -eq 0))
    {
        return $false
    }
    else
    {
        return $true
    }
}

Get div to take up 100% body height, minus fixed-height header and footer

Trying to calculate the header and footer is bad :( A design should be simple, self explanatory. Plain easy. Calculations are just...not easy. Not easy for human and a bit hard on machines.

What you're looking for is a subset of the Holy Grail design.

Here's an implementation using the flex display. It includes side bars in addition to the footer and header. Enjoy:

<!DOCTYPE html>
<html style="height: 100%">
  <head>
    <meta charset=utf-8 />
    <title>Holy Grail</title>
    <!-- Reset browser defaults -->
    <link rel="stylesheet" href="reset.css">
  </head>
  <body style="display: flex; height: 100%; flex-direction: column">
    <div>HEADER<br/>------------
    </div>
    <!-- No need for 'flex-direction: row' because it's the default value -->
    <div style="display: flex; flex: 1">
      <div>NAV|</div>
      <div style="flex: 1; overflow: auto">
        CONTENT - START<br/>
        <script>
        for (var i=0 ; i<1000 ; ++i) {
          document.write(" Very long content!");
        }
        </script>
        <br/>CONTENT - END
      </div>
      <div>|SIDE</div>
    </div>
    <div>------------<br/>FOOTER</div>
  </body>
</html>

Fastest way to reset every value of std::vector<int> to 0

try

std::fill

and also

std::size siz = vec.size();
//no memory allocating
vec.resize(0);
vec.resize(siz, 0);

How to display my application's errors in JSF?

In case anyone was curious, I was able to figure this out based on all of your responses combined!

This is in the Facelet:

<h:form id="myform">
  <h:inputSecret value="#{createNewPassword.newPassword1}" id="newPassword1" />
  <h:message class="error" for="newPassword1" id="newPassword1Error" />
  <h:inputSecret value="#{createNewPassword.newPassword2}" id="newPassword2" />
  <h:message class="error" for="newPassword2" id="newPassword2Error" />
  <h:commandButton value="Continue" action="#{createNewPassword.continueButton}" />
</h:form>

This is in the continueButton() method:

FacesContext.getCurrentInstance().addMessage("myForm:newPassword1", new FacesMessage(PASSWORDS_DONT_MATCH, PASSWORDS_DONT_MATCH));

And it works! Thanks for the help!

Get Cell Value from Excel Sheet with Apache Poi

You have to use the FormulaEvaluator, as shown here. This will return a value that is either the value present in the cell or the result of the formula if the cell contains such a formula :

FileInputStream fis = new FileInputStream("/somepath/test.xls");
Workbook wb = new HSSFWorkbook(fis); //or new XSSFWorkbook("/somepath/test.xls")
Sheet sheet = wb.getSheetAt(0);
FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();

// suppose your formula is in B3
CellReference cellReference = new CellReference("B3"); 
Row row = sheet.getRow(cellReference.getRow());
Cell cell = row.getCell(cellReference.getCol()); 

if (cell!=null) {
    switch (evaluator.evaluateFormulaCell(cell)) {
        case Cell.CELL_TYPE_BOOLEAN:
            System.out.println(cell.getBooleanCellValue());
            break;
        case Cell.CELL_TYPE_NUMERIC:
            System.out.println(cell.getNumericCellValue());
            break;
        case Cell.CELL_TYPE_STRING:
            System.out.println(cell.getStringCellValue());
            break;
        case Cell.CELL_TYPE_BLANK:
            break;
        case Cell.CELL_TYPE_ERROR:
            System.out.println(cell.getErrorCellValue());
            break;

        // CELL_TYPE_FORMULA will never occur
        case Cell.CELL_TYPE_FORMULA: 
            break;
    }
}

if you need the exact contant (ie the formla if the cell contains a formula), then this is shown here.

Edit : Added a few example to help you.

first you get the cell (just an example)

Row row = sheet.getRow(rowIndex+2);    
Cell cell = row.getCell(1);   

If you just want to set the value into the cell using the formula (without knowing the result) :

 String formula ="ABS((1-E"+(rowIndex + 2)+"/D"+(rowIndex + 2)+")*100)";    
 cell.setCellFormula(formula);    
 cell.setCellStyle(this.valueRightAlignStyleLightBlueBackground);

if you want to change the message if there is an error in the cell, you have to change the formula to do so, something like

IF(ISERR(ABS((1-E3/D3)*100));"N/A"; ABS((1-E3/D3)*100))

(this formula check if the evaluation return an error and then display the string "N/A", or the evaluation if this is not an error).

if you want to get the value corresponding to the formula, then you have to use the evaluator.

Hope this help,
Guillaume

How do I split a string into an array of characters?

A string in Javascript is already a character array.

You can simply access any character in the array as you would any other array.

var s = "overpopulation";
alert(s[0]) // alerts o.

UPDATE

As is pointed out in the comments below, the above method for accessing a character in a string is part of ECMAScript 5 which certain browsers may not conform to.

An alternative method you can use is charAt(index).

var s = "overpopulation";
    alert(s.charAt(0)) // alerts o.

Apache is downloading php files instead of displaying them

I came across this issue today and none of the solutions described worked for me. So here is another possible cause:

If you have something like

AddHandler x-mapp-php6 .php3 .php4 .php .phtml

in a .htaccess file of your web content folder, it can cause your PHP scripts to stop working. In my case the server did not know the x-mapp-php6 type, since that .htaccess file was something I imported from a different web host when I transferred the website content.

Just removing the AddHandler line from the .htaccess file solved it for me.

SystemError: Parent module '' not loaded, cannot perform relative import

If you go one level up in running the script in the command line of your bash shell, the issue will be resolved. To do this, use cd .. command to change the working directory in which your script will be running. The result should look like this:

[username@localhost myProgram]$

rather than this:

[username@localhost app]$

Once you are there, instead of running the script in the following format:

python3 mymodule.py

Change it to this:

python3 app/mymodule.py

This process can be repeated once again one level up depending on the structure of your Tree diagram. Please also include the compilation command line that is giving you that mentioned error message.

Read/Parse text file line by line in VBA

For completeness; working with the data loaded into memory;

dim hf As integer: hf = freefile
dim lines() as string, i as long

open "c:\bla\bla.bla" for input as #hf
    lines = Split(input$(LOF(hf), #hf), vbnewline)
close #hf

for i = 0 to ubound(lines)
    debug.? "Line"; i; "="; lines(i)
next

Detecting negative numbers

You could use a ternary operator like this one, to make it a one liner.

echo ($profitloss < 0) ? 'false' : 'true';

DIV table colspan: how?

I've achieved this by separating them in different , e.g.:

<div class="table">
  <div class="row">
    <div class="col">TD</div>
    <div class="col">TD</div>
    <div class="col">TD</div>
    <div class="col">TD</div>
    <div class="col">TD</div>
  </div>
</div>
<div class="table">
  <div class="row">
    <div class="col">TD</div>
  </div>
</div>

or you can define different classes for each tables

<div class="table2">
  <div class="row2">
    <div class="col2">TD</div>
  </div>
</div>

From the user point of view they behave identically.

Granted it doesn't solve all colspan/rowspan problems but it does answer my need of the time.

What's the difference between "Request Payload" vs "Form Data" as seen in Chrome dev tools Network tab

The Request Payload - or to be more precise: payload body of a HTTP Request - is the data normally send by a POST or PUT Request. It's the part after the headers and the CRLF of a HTTP Request.

A request with Content-Type: application/json may look like this:

POST /some-path HTTP/1.1
Content-Type: application/json

{ "foo" : "bar", "name" : "John" }

If you submit this per AJAX the browser simply shows you what it is submitting as payload body. That’s all it can do because it has no idea where the data is coming from.

If you submit a HTML-Form with method="POST" and Content-Type: application/x-www-form-urlencoded or Content-Type: multipart/form-data your request may look like this:

POST /some-path HTTP/1.1
Content-Type: application/x-www-form-urlencoded

foo=bar&name=John

In this case the form-data is the request payload. Here the Browser knows more: it knows that bar is the value of the input-field foo of the submitted form. And that’s what it is showing to you.

So, they differ in the Content-Type but not in the way data is submitted. In both cases the data is in the message-body. And Chrome distinguishes how the data is presented to you in the Developer Tools.

What does LINQ return when the results are empty

It won't throw exception, you'll get an empty list.

Display QImage with QtGui

Drawing an image using a QLabel seems like a bit of a kludge to me. With newer versions of Qt you can use a QGraphicsView widget. In Qt Creator, drag a Graphics View widget onto your UI and name it something (it is named mainImage in the code below). In mainwindow.h, add something like the following as private variables to your MainWindow class:

QGraphicsScene *scene;
QPixmap image;

Then just edit mainwindow.cpp and make the constructor something like this:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent), ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    image.load("myimage.png");
    scene = new QGraphicsScene(this);
    scene->addPixmap(image);
    scene->setSceneRect(image.rect());

    ui->mainImage->setScene(scene);
}

Form Submission without page refresh

The problem is the Method 'POST' your form is submitting by using the "post" method, and in the AJAX you are using "GET".

PHP date time greater than today

You are not comparing dates. You are comparing strings. In the world of string comparisons, 09/17/2015 > 01/02/2016 because 09 > 01. You need to either put your date in a comparable string format or compare DateTime objects which are comparable.

<?php
 $date_now = date("Y-m-d"); // this format is string comparable

if ($date_now > '2016-01-02') {
    echo 'greater than';
}else{
    echo 'Less than';
}

Demo

Or

<?php
 $date_now = new DateTime();
 $date2    = new DateTime("01/02/2016");

if ($date_now > $date2) {
    echo 'greater than';
}else{
    echo 'Less than';
}

Demo

How to assign text size in sp value using java code

Cleaner and more reusable approach is

define text size in dimens.xml file inside res/values/ directory:

</resources>
   <dimen name="text_medium">14sp</dimen>
</resources>

and then apply it to the TextView:

textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.text_medium));

mysql said: Cannot connect: invalid settings. xampp

If you are facing this issue after changing password in phpmyadmin, paste the old password (passwd before change) in xampp\phpMyAdmin\config.inc.php :

$cfg['Servers'][$i]['password'] = '**old password here**';

Hope, it would work :)

Android Facebook integration with invalid key hash

You must create two key hashes, one for Debug and one for Release.

For the Debug key hash:

On OS X, run:

keytool -exportcert -alias androiddebugkey -keystore ~/.android/debug.keystore | openssl sha1 -binary | openssl base64

On Windows, run:

keytool -exportcert -alias androiddebugkey -keystore %HOMEPATH%\.android\debug.keystore | openssl sha1 -binary | openssl
base64

Debug key hashes source

For the Release key hash:

On OS X, run (replace what is between <> with your values):

keytool -exportcert -alias <RELEASE_KEY_ALIAS> -keystore <RELEASE_KEY_PATH> | openssl sha1 -binary | openssl base64

On Windows, use (replace what is between <> with your values):

keytool -exportcert -alias <RELEASE_KEY_ALIAS> -keystore <RELEASE_KEY_PATH> | openssl sha1 -binary | openssl base64

Release key hashes source

What is __main__.py?

What is the __main__.py file for?

When creating a Python module, it is common to make the module execute some functionality (usually contained in a main function) when run as the entry point of the program. This is typically done with the following common idiom placed at the bottom of most Python files:

if __name__ == '__main__':
    # execute only if run as the entry point into the program
    main()

You can get the same semantics for a Python package with __main__.py, which might have the following structure:

.
+-- demo
    +-- __init__.py
    +-- __main__.py

To see this, paste the below into a Python 3 shell:

from pathlib import Path

demo = Path.cwd() / 'demo'
demo.mkdir()

(demo / '__init__.py').write_text("""
print('demo/__init__.py executed')

def main():
    print('main() executed')
""")

(demo / '__main__.py').write_text("""
print('demo/__main__.py executed')

from demo import main

main()
""")

We can treat demo as a package and actually import it, which executes the top-level code in the __init__.py (but not the main function):

>>> import demo
demo/__init__.py executed

When we use the package as the entry point to the program, we perform the code in the __main__.py, which imports the __init__.py first:

$ python -m demo
demo/__init__.py executed
demo/__main__.py executed
main() executed

You can derive this from the documentation. The documentation says:

__main__ — Top-level script environment

'__main__' is the name of the scope in which top-level code executes. A module’s __name__ is set equal to '__main__' when read from standard input, a script, or from an interactive prompt.

A module can discover whether or not it is running in the main scope by checking its own __name__, which allows a common idiom for conditionally executing code in a module when it is run as a script or with python -m but not when it is imported:

if __name__ == '__main__':
     # execute only if run as a script
     main()

For a package, the same effect can be achieved by including a __main__.py module, the contents of which will be executed when the module is run with -m.

Zipped

You can also zip up this directory, including the __main__.py, into a single file and run it from the command line like this - but note that zipped packages can't execute sub-packages or submodules as the entry point:

from pathlib import Path

demo = Path.cwd() / 'demo2'
demo.mkdir()

(demo / '__init__.py').write_text("""
print('demo2/__init__.py executed')

def main():
    print('main() executed')
""")

(demo / '__main__.py').write_text("""
print('demo2/__main__.py executed')

from __init__ import main

main()
""")

Note the subtle change - we are importing main from __init__ instead of demo2 - this zipped directory is not being treated as a package, but as a directory of scripts. So it must be used without the -m flag.

Particularly relevant to the question - zipapp causes the zipped directory to execute the __main__.py by default - and it is executed first, before __init__.py:

$ python -m zipapp demo2 -o demo2zip
$ python demo2zip
demo2/__main__.py executed
demo2/__init__.py executed
main() executed

Note again, this zipped directory is not a package - you cannot import it either.

how do I loop through a line from a csv file in powershell

A slightly other way of iterating through each column of each line of a CSV-file would be

$path = "d:\scratch\export.csv"
$csv = Import-Csv -path $path

foreach($line in $csv)
{ 
    $properties = $line | Get-Member -MemberType Properties
    for($i=0; $i -lt $properties.Count;$i++)
    {
        $column = $properties[$i]
        $columnvalue = $line | Select -ExpandProperty $column.Name

        # doSomething $column.Name $columnvalue 
        # doSomething $i $columnvalue 
    }
} 

so you have the choice: you can use either $column.Name to get the name of the column, or $i to get the number of the column

How do I flush the cin buffer?

#include <stdio_ext.h>

and then use function

__fpurge(stdin)

How to show/hide JPanels in a JFrame?

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * Style1.java
 *
 * Created on May 5, 2011, 6:31:16 AM
 */
package Test;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JOptionPane;

/**
 *
 * @author Sameera
 */
public class Style2 extends javax.swing.JFrame {

    /** Creates new form Style1 */
    public Style2() {
        initComponents();
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        cmd_SH = new javax.swing.JButton();
        pnl_2 = new javax.swing.JPanel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));

        cmd_SH.setText("Hide");
        cmd_SH.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                cmd_SHActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(558, Short.MAX_VALUE)
                .addComponent(cmd_SH)
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(236, Short.MAX_VALUE)
                .addComponent(cmd_SH)
                .addContainerGap())
        );

        pnl_2.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));

        javax.swing.GroupLayout pnl_2Layout = new javax.swing.GroupLayout(pnl_2);
        pnl_2.setLayout(pnl_2Layout);
        pnl_2Layout.setHorizontalGroup(
            pnl_2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 621, Short.MAX_VALUE)
        );
        pnl_2Layout.setVerticalGroup(
            pnl_2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 270, Short.MAX_VALUE)
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(pnl_2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(pnl_2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(17, Short.MAX_VALUE))
        );

        pack();
    }// </editor-fold>

    private void cmd_SHActionPerformed(java.awt.event.ActionEvent evt) {                                       


        System.out.println(evt.getActionCommand());
        if (evt.getActionCommand().equals("Hide")) {
            pnl_2.setVisible(false);
            cmd_SH.setText("Show");
            this.setSize(643, 294);
            this.pack();


        }
        if (evt.getActionCommand().equals("Show")) {
            pnl_2.setVisible(true);
            cmd_SH.setText("Hide");
            this.setSize(643, 583);
            this.pack();    
        }
    }                                      

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new Style1().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify
    private javax.swing.JButton cmd_SH;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel pnl_2;
    // End of variables declaration
}

How to convert webpage into PDF by using Python

Here is a simple solution using QT. I found this as part of an answer to a different question on StackOverFlow. I tested it on Windows.

from PyQt4.QtGui import QTextDocument, QPrinter, QApplication

import sys
app = QApplication(sys.argv)

doc = QTextDocument()
location = "c://apython//Jim//html//notes.html"
html = open(location).read()
doc.setHtml(html)

printer = QPrinter()
printer.setOutputFileName("foo.pdf")
printer.setOutputFormat(QPrinter.PdfFormat)
printer.setPageSize(QPrinter.A4);
printer.setPageMargins (15,15,15,15,QPrinter.Millimeter);

doc.print_(printer)
print "done!"

Cloning git repo causes error - Host key verification failed. fatal: The remote end hung up unexpectedly

The issue could be that Github isn't present in your ~/.ssh/known_hosts file.

Append GitHub to the list of authorized hosts:

ssh-keyscan -H github.com >> ~/.ssh/known_hosts

Maintain/Save/Restore scroll position when returning to a ListView

Isn't simply android:saveEnabled="true" in the ListView xml declaration enough?

What are .NumberFormat Options In Excel VBA?

Note this was done on Excel for Mac 2011 but should be same for Windows

Macro:

Sub numberformats()
  Dim rng As Range
  Set rng = Range("A24:A35")
  For Each c In rng
    Debug.Print c.NumberFormat
  Next c
End Sub

Result:

General     General
Number      0
Currency    $#,##0.00;[Red]$#,##0.00
Accounting  _($* #,##0.00_);_($* (#,##0.00);_($* "-"??_);_(@_)
Date        m/d/yy
Time        [$-F400]h:mm:ss am/pm
Percentage  0.00%
Fraction    # ?/?
Scientific  0.00E+00
Text        @
Special     ;;
Custom      #,##0_);[Red](#,##0)

(I just picked a random entry for custom)

GlobalConfiguration.Configure() not present after Web API 2 and .NET 4.5.1 migration

None of these solutions worked for me. I had a tangle of Nuget packages that couldn't update because of circular dependencies on each other.

I would up having to fix this the old-fashioned way. I created a new MVC/web api project and manually copied System.Web.Http and System.Web.Http.WebHost from the new project into the Nuget folders of the exisitng solution. From there I updated the references by, OMG, "browsing" and fixed the problem.

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

How to persist data in a dockerized postgres database using volumes

I would avoid using a relative path. Remember that docker is a daemon/client relationship.

When you are executing the compose, it's essentially just breaking down into various docker client commands, which are then passed to the daemon. That ./database is then relative to the daemon, not the client.

Now, the docker dev team has some back and forth on this issue, but the bottom line is it can have some unexpected results.

In short, don't use a relative path, use an absolute path.

How do I parse command line arguments in Java?

I want to show you my implementation: ReadyCLI

Advantages:

  • for lazy programmers: a very small number of classes to learn, just see the two small examples on the README in the repository and you are already at 90% of learning; just start coding your CLI/Parser without any other knowledge; ReadyCLI allows coding CLIs in the most natural way;
  • it is designed with Developer Experience in mind; it largely uses the Builder design pattern and functional interfaces for Lambda Expressions, to allow a very quick coding;
  • it supports Options, Flags and Sub-Commands;
  • it allows to parse arguments from command-line and to build more complex and interactive CLIs;
  • a CLI can be started on Standard I/O just as easily as on any other I/O interface, such as sockets;
  • it gives great support for documentation of commands.

I developed this project as I needed new features (options, flag, sub-commands) and that could be used in the simplest possible way in my projects.

UIDevice uniqueIdentifier deprecated - What to do now?

iOS 11 has introduced the DeviceCheck framework. It has a fullproof solution for uniquely identifying the device.

How to upload a project to Github

The best way to git is to actually start Gitting. Try out this website which makes you go step by step on what are the essential ways for performing functions on command line for pushing a Project on GitHub

This is called try.github.io or you could also take up a course on codeAcademy

How to get the EXIF data from a file using C#

You can use TagLib# which is used by applications such as F-Spot. Besides Exif, it will read a good amount of metadata formats for image, audio and video.

I also like ExifUtils API but it is buggy and is not actively developed.

How do I dump an object's fields to the console?

I came across this thread because I was looking for something similar. I like the responses and they gave me some ideas so I tested the .to_hash method and worked really well for the use case too. soo:

object.to_hash

What is the purpose of wrapping whole Javascript files in anonymous functions like “(function(){ … })()”?

It's usually to namespace (see later) and control the visibility of member functions and/or variables. Think of it like an object definition. The technical name for it is an Immediately Invoked Function Expression (IIFE). jQuery plugins are usually written like this.

In Javascript, you can nest functions. So, the following is legal:

function outerFunction() {
   function innerFunction() {
      // code
   }
}

Now you can call outerFunction(), but the visiblity of innerFunction() is limited to the scope of outerFunction(), meaning it is private to outerFunction(). It basically follows the same principle as variables in Javascript:

var globalVariable;

function someFunction() {
   var localVariable;
}

Correspondingly:

function globalFunction() {

   var localFunction1 = function() {
       //I'm anonymous! But localFunction1 is a reference to me!
   };

   function localFunction2() {
      //I'm named!
   }
}

In the above scenario, you can call globalFunction() from anywhere, but you cannot call localFunction1 or localFunction2.

What you're doing when you write (function() { ... })(), is you're making the code inside the first set of parentheses a function literal (meaning the whole "object" is actually a function). After that, you're self-invoking the function (the final ()) that you just defined. So the major advantage of this as I mentioned before, is that you can have private methods/functions and properties:

(function() {
   var private_var;

   function private_function() {
     //code
   }
})();

In the first example, you would explicitly invoke globalFunction by name to run it. That is, you would just do globalFunction() to run it. But in the above example, you're not just defining a function; you're defining and invoking it in one go. This means that when the your JavaScript file is loaded, it is immediately executed. Of course, you could do:

function globalFunction() {
    // code
}
globalFunction();

The behavior would largely be the same except for one significant difference: you avoid polluting the global scope when you use an IIFE (as a consequence it also means that you cannot invoke the function multiple times since it doesn't have a name, but since this function is only meant to be executed once it really isn't an issue).

The neat thing with IIFEs is that you can also define things inside and only expose the parts that you want to the outside world so (an example of namespacing so you can basically create your own library/plugin):

var myPlugin = (function() {
 var private_var;

 function private_function() {
 }

 return {
    public_function1: function() {
    },
    public_function2: function() {
    }
 }
})()

Now you can call myPlugin.public_function1(), but you cannot access private_function()! So pretty similar to a class definition. To understand this better, I recommend the following links for some further reading:

EDIT

I forgot to mention. In that final (), you can pass anything you want inside. For example, when you create jQuery plugins, you pass in jQuery or $ like so:

(function(jQ) { ... code ... })(jQuery) 

So what you're doing here is defining a function that takes in one parameter (called jQ, a local variable, and known only to that function). Then you're self-invoking the function and passing in a parameter (also called jQuery, but this one is from the outside world and a reference to the actual jQuery itself). There is no pressing need to do this, but there are some advantages:

  • You can redefine a global parameter and give it a name that makes sense in the local scope.
  • There is a slight performance advantage since it is faster to look things up in the local scope instead of having to walk up the scope chain into the global scope.
  • There are benefits for compression (minification).

Earlier I described how these functions run automatically at startup, but if they run automatically who is passing in the arguments? This technique assumes that all the parameters you need are already defined as global variables. So if jQuery wasn't already defined as a global variable this example would not work. As you might guess, one things jquery.js does during its initialization is define a 'jQuery' global variable, as well as its more famous '$' global variable, which allows this code to work after jQuery has been included.

How to install pkg config in windows?

I would like to extend the answer of @dzintars about the Cygwin version of pkg-config in that focus how should one use it properly with CMake, because I see various comments about CMake in this topic.

I have experienced many troubles with CMake + Cygwin's pkg-config and I want to share my experience how to avoid them.

1. The symlink C:/Cygwin64/bin/pkg-config -> pkgconf.exe does not work in Windows console.

It is not a native Windows .lnk symlink and it won't be callable in Windows console cmd.exe even if you add ".;" to your %PATHEXT% (see https://www.mail-archive.com/[email protected]/msg104088.html).

It won't work from CMake, because CMake calls pkg-config with the method execute_process() (FindPkgConfig.cmake) which opens a new cmd.exe.

Solution: Add -DPKG_CONFIG_EXECUTABLE=C:/Cygwin64/bin/pkgconf.exe to the CMake command line (or set it in CMakeLists.txt).

2. Cygwin's pkg-config recognizes only Cygwin paths in PKG_CONFIG_PATH (no Windows paths).

For example, on my system the .pc files are located in C:\Cygwin64\usr\x86_64-w64-mingw32\sys-root\mingw\lib\pkgconfig. The following three paths are valid, but only path C works in PKG_CONFIG_PATH:

  • A) c:/Cygwin64/usr/x86_64-w64-mingw32/sys-root/mingw/lib/pkgconfig - does not work.
  • B) /c/cygdrive/usr/x86_64-w64-mingw32/sys-root/mingw/lib/pkgconfig - does not work.
  • C) /usr/x86_64-w64-mingw32/sys-root/mingw/lib/pkgconfig - works.

Solution: add .pc files location always as a Cygwin path into PKG_CONFIG_PATH.

3) CMake converts forward slashes to backslashes in PKG_CONFIG_PATH on Cygwin.

It happens due to the bug https://gitlab.kitware.com/cmake/cmake/-/issues/21629. It prevents using the workaround described in [2].

Solution: manually update the function _pkg_set_path_internal() in the file C:/Program Files/CMake/share/cmake-3.x/Modules/FindPkgConfig.cmake. Comment/remove the line:

file(TO_NATIVE_PATH "${_pkgconfig_path}" _pkgconfig_path)

4) CMAKE_PREFIX_PATH, CMAKE_FRAMEWORK_PATH, CMAKE_APPBUNDLE_PATH have no effect on pkg-config in Cygwin.

Reason: the bug https://gitlab.kitware.com/cmake/cmake/-/issues/21775.

Solution: Use only PKG_CONFIG_PATH as an environment variable if you run CMake builds on Cygwin. Forget about CMAKE_PREFIX_PATH, CMAKE_FRAMEWORK_PATH, CMAKE_APPBUNDLE_PATH.

Could not execute menu item (internal error)[Exception] - When changing PHP version from 5.3.1 to 5.2.9

If you are using Windows try out the following:

  1. Press (Windows+R)
  2. enter "services.msc" and click "OK"
  3. locate service with name 'wampapache'

and check if it's status is 'Running'. In case not, right click >> start.

Hope this helps!


If you have removed WAMP from boot services, it won't work – try the following:

  • Press (Windows+R)
  • enter "services.msc" and click "OK"
  • locate service with name 'wampapache'
  • Right click wampapache and wampmysqld, Click 'properties'
  • and change Start Type to Manual or automatic

This will work!

Simple way to sort strings in the (case sensitive) alphabetical order

I recently answered a similar question here. Applying the same approach to your problem would yield following solution:

list.sort(
  p2Ord(stringOrd, stringOrd).comap(new F<String, P2<String, String>>() {
    public P2<String, String> f(String s) {
      return p(s.toLowerCase(), s);
    }
  })
);

What is the difference between a web API and a web service?

All WebServices is API but all API is not WebServices, API which is exposed on Web is called web services.

graphing an equation with matplotlib

This is because in line

graph(x**3+2*x-4, range(-10, 11))

x is not defined.

The easiest way is to pass the function you want to plot as a string and use eval to evaluate it as an expression.

So your code with minimal modifications will be

import numpy as np  
import matplotlib.pyplot as plt  
def graph(formula, x_range):  
    x = np.array(x_range)  
    y = eval(formula)
    plt.plot(x, y)  
    plt.show()

and you can call it as

graph('x**3+2*x-4', range(-10, 11))

Difference between web reference and service reference?

A Web Reference allows you to communicate with any service based on any technology that implements the WS-I Basic Profile 1.1, and exposes the relevant metadata as WSDL. Internally, it uses the ASMX communication stack on the client's side.

A Service Reference allows you to communicate with any service based on any technology that implements any of the many protocols supported by WCF (including but not limited to WS-I Basic Profile). Internally, it uses the WCF communication stack on the client side.

Note that both these definitions are quite wide, and both include services not written in .NET.

It is perfectly possible (though not recommended) to add a Web Reference that points to a WCF service, as long as the WCF endpoint uses basicHttpBinding or some compatible custom variant.

It is also possible to add a Service Reference that points to an ASMX service. When writing new code, you should always use a Service Reference simply because it is more flexible and future-proof.

How to make an ImageView with rounded corners?

If you are using Glide Library this would be helpful:

Glide.with(getApplicationContext())
     .load(image_url)
     .asBitmap()
     .centerCrop()
     .into(new BitmapImageViewTarget(imageView) {
        @Override
        protected void setResource(Bitmap resource) {
          RoundedBitmapDrawable circularBitmapDrawable =
                       RoundedBitmapDrawableFactory.create(getApplicationContext().getResources(), resource);
          circularBitmapDrawable.setCornerRadius(dpToPx(10));
          circularBitmapDrawable.setAntiAlias(true);
          imageView.setImageDrawable(circularBitmapDrawable);
        }
     });


public int dpToPx(int dp) {
  DisplayMetrics displayMetrics = getApplicationContext().getResources().getDisplayMetrics();
  return Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
}

jQuery remove all list items from an unordered list

$("ul").empty() should work and clear the childrens. you can see it here:

http://jsfiddle.net/ZKFA5/

Subtract two variables in Bash

This is how I always do maths in Bash:

count=$(echo "$FIRSTV - $SECONDV"|bc)
echo $count

How to layout multiple panels on a jFrame? (java)

The JPanel is actually only a container where you can put different elements in it (even other JPanels). So in your case I would suggest one big JPanel as some sort of main container for your window. That main panel you assign a Layout that suits your needs ( here is an introduction to the layouts).

After you set the layout to your main panel you can add the paint panel and the other JPanels you want (like those with the text in it..).

  JPanel mainPanel = new JPanel();
  mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));

  JPanel paintPanel = new JPanel();
  JPanel textPanel = new JPanel();

  mainPanel.add(paintPanel);
  mainPanel.add(textPanel);

This is just an example that sorts all sub panels vertically (Y-Axis). So if you want some other stuff at the bottom of your mainPanel (maybe some icons or buttons) that should be organized with another layout (like a horizontal layout), just create again a new JPanel as a container for all the other stuff and set setLayout(new BoxLayout(mainPanel, BoxLayout.X_AXIS).

As you will find out, the layouts are quite rigid and it may be difficult to find the best layout for your panels. So don't give up, read the introduction (the link above) and look at the pictures – this is how I do it :)

Or you can just use NetBeans to write your program. There you have a pretty easy visual editor (drag and drop) to create all sorts of Windows and Frames. (only understanding the code afterwards is ... tricky sometimes.)

EDIT

Since there are some many people interested in this question, I wanted to provide a complete example of how to layout a JFrame to make it look like OP wants it to.

The class is called MyFrame and extends swings JFrame

public class MyFrame extends javax.swing.JFrame{

    // these are the components we need.
    private final JSplitPane splitPane;  // split the window in top and bottom
    private final JPanel topPanel;       // container panel for the top
    private final JPanel bottomPanel;    // container panel for the bottom
    private final JScrollPane scrollPane; // makes the text scrollable
    private final JTextArea textArea;     // the text
    private final JPanel inputPanel;      // under the text a container for all the input elements
    private final JTextField textField;   // a textField for the text the user inputs
    private final JButton button;         // and a "send" button

    public MyFrame(){

        // first, lets create the containers:
        // the splitPane devides the window in two components (here: top and bottom)
        // users can then move the devider and decide how much of the top component
        // and how much of the bottom component they want to see.
        splitPane = new JSplitPane();

        topPanel = new JPanel();         // our top component
        bottomPanel = new JPanel();      // our bottom component

        // in our bottom panel we want the text area and the input components
        scrollPane = new JScrollPane();  // this scrollPane is used to make the text area scrollable
        textArea = new JTextArea();      // this text area will be put inside the scrollPane

        // the input components will be put in a separate panel
        inputPanel = new JPanel();
        textField = new JTextField();    // first the input field where the user can type his text
        button = new JButton("send");    // and a button at the right, to send the text

        // now lets define the default size of our window and its layout:
        setPreferredSize(new Dimension(400, 400));     // let's open the window with a default size of 400x400 pixels
        // the contentPane is the container that holds all our components
        getContentPane().setLayout(new GridLayout());  // the default GridLayout is like a grid with 1 column and 1 row,
        // we only add one element to the window itself
        getContentPane().add(splitPane);               // due to the GridLayout, our splitPane will now fill the whole window

        // let's configure our splitPane:
        splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT);  // we want it to split the window verticaly
        splitPane.setDividerLocation(200);                    // the initial position of the divider is 200 (our window is 400 pixels high)
        splitPane.setTopComponent(topPanel);                  // at the top we want our "topPanel"
        splitPane.setBottomComponent(bottomPanel);            // and at the bottom we want our "bottomPanel"

        // our topPanel doesn't need anymore for this example. Whatever you want it to contain, you can add it here
        bottomPanel.setLayout(new BoxLayout(bottomPanel, BoxLayout.Y_AXIS)); // BoxLayout.Y_AXIS will arrange the content vertically

        bottomPanel.add(scrollPane);                // first we add the scrollPane to the bottomPanel, so it is at the top
        scrollPane.setViewportView(textArea);       // the scrollPane should make the textArea scrollable, so we define the viewport
        bottomPanel.add(inputPanel);                // then we add the inputPanel to the bottomPanel, so it under the scrollPane / textArea

        // let's set the maximum size of the inputPanel, so it doesn't get too big when the user resizes the window
        inputPanel.setMaximumSize(new Dimension(Integer.MAX_VALUE, 75));     // we set the max height to 75 and the max width to (almost) unlimited
        inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.X_AXIS));   // X_Axis will arrange the content horizontally

        inputPanel.add(textField);        // left will be the textField
        inputPanel.add(button);           // and right the "send" button

        pack();   // calling pack() at the end, will ensure that every layout and size we just defined gets applied before the stuff becomes visible
    }

    public static void main(String args[]){
        EventQueue.invokeLater(new Runnable(){
            @Override
            public void run(){
                new MyFrame().setVisible(true);
            }
        });
    }
}

Please be aware that this is only an example and there are multiple approaches to layout a window. It all depends on your needs and if you want the content to be resizable / responsive. Another really good approach would be the GridBagLayout which can handle quite complex layouting, but which is also quite complex to learn.

RabbitMQ / AMQP: single queue, multiple consumers for same message?

Can I have each consumer receive the same messages? Ie, both consumers get message 1, 2, 3, 4, 5, 6? What is this called in AMQP/RabbitMQ speak? How is it normally configured?

No, not if the consumers are on the same queue. From RabbitMQ's AMQP Concepts guide:

it is important to understand that, in AMQP 0-9-1, messages are load balanced between consumers.

This seems to imply that round-robin behavior within a queue is a given, and not configurable. Ie, separate queues are required in order to have the same message ID be handled by multiple consumers.

Is this commonly done? Should I just have the exchange route the message into two separate queues, with a single consumer, instead?

No it's not, single queue/multiple consumers with each each consumer handling the same message ID isn't possible. Having the exchange route the message onto into two separate queues is indeed better.

As I don't require too complex routing, a fanout exchange will handle this nicely. I didn't focus too much on Exchanges earlier as node-amqp has the concept of a 'default exchange' allowing you to publish messages to a connection directly, however most AMQP messages are published to a specific exchange.

Here's my fanout exchange, both sending and receiving:

var amqp = require('amqp');
var connection = amqp.createConnection({ host: "localhost", port: 5672 });
var count = 1;

connection.on('ready', function () {
  connection.exchange("my_exchange", options={type:'fanout'}, function(exchange) {   

    var sendMessage = function(exchange, payload) {
      console.log('about to publish')
      var encoded_payload = JSON.stringify(payload);
      exchange.publish('', encoded_payload, {})
    }

    // Recieve messages
    connection.queue("my_queue_name", function(queue){
      console.log('Created queue')
      queue.bind(exchange, ''); 
      queue.subscribe(function (message) {
        console.log('subscribed to queue')
        var encoded_payload = unescape(message.data)
        var payload = JSON.parse(encoded_payload)
        console.log('Recieved a message:')
        console.log(payload)
      })
    })

    setInterval( function() {    
      var test_message = 'TEST '+count
      sendMessage(exchange, test_message)  
      count += 1;
    }, 2000) 
 })
})