How can I write a regex which matches non greedy?
The non-greedy ? works perfectly fine. It's just that you need to select dot matches all option in the regex engines (regexpal, the engine you used, also has this option) you are testing with. This is because, regex engines generally don't match line breaks when you use .. You need to tell them explicitly that you want to match line-breaks too with .
For example,
<img\s.*?>
works fine!
Check the results here.
Also, read about how dot behaves in various regex flavours.
URL format with GET parameters?
No, how you are doing it is correct.
http://www.w3.org/MarkUp/html-spec/html-spec_8.html#SEC8.2.2
LINQ select one field from list of DTO objects to array
You can use:
var mySKUs = myLines.Select(l => l.Sku).ToList();
The Select method, in this case, performs a mapping from IEnumerable<Line> to IEnumerable<string> (the SKU), then ToList() converts it to a List<string>.
Note that this requires using System.Linq; to be at the top of your .cs file.
Why doesn't file_get_contents work?
//JUST ADD urlencode();
$url = urlencode("http://maps.googleapis.com/maps/api/geocode/json?address=$adr&sensor=false");
<html>
<head>
<title>Test File</title>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false">
</script>
</head>
<body>
<?php
$adr = 'Sydney+NSW';
echo $adr;
$url = "http://maps.googleapis.com/maps/api/geocode/json?address=$adr&sensor=false";
echo '<p>'.$url.'</p>';
echo file_get_contents($url);
print '<p>'.file_get_contents($url).'</p>';
$jsonData = file_get_contents($url);
echo $jsonData;
?>
</body>
</html>
How do I test if a recordSet is empty? isNull?
A simple way is to write it:
Dim rs As Object
Set rs = Me.Recordset.Clone
If Me.Recordset.RecordCount = 0 then 'checks for number of records
msgbox "There is no records"
End if
Perform commands over ssh with Python
You can use any of these commands, this will help you to give a password also.
cmd = subprocess.run(["sshpass -p 'password' ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null [email protected] ps | grep minicom"], shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
print(cmd.stdout)
OR
cmd = subprocess.getoutput("sshpass -p 'password' ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null [email protected] ps | grep minicom")
print(cmd)
How do I get a YouTube video thumbnail from the YouTube API?
This is my client-side-only no-API-key-required solution.
YouTube.parse('https://www.youtube.com/watch?v=P3DGwyl0mJQ').then(_ => console.log(_))
The code:
import { parseURL, parseQueryString } from './url'
import { getImageSize } from './image'
const PICTURE_SIZE_NAMES = [
// 1280 x 720.
// HD aspect ratio.
'maxresdefault',
// 629 x 472.
// non-HD aspect ratio.
'sddefault',
// For really old videos not having `maxresdefault`/`sddefault`.
'hqdefault'
]
// - Supported YouTube URL formats:
// - http://www.youtube.com/watch?v=My2FRPA3Gf8
// - http://youtu.be/My2FRPA3Gf8
export default
{
parse: async function(url)
{
// Get video ID.
let id
const location = parseURL(url)
if (location.hostname === 'www.youtube.com') {
if (location.search) {
const query = parseQueryString(location.search.slice('/'.length))
id = query.v
}
} else if (location.hostname === 'youtu.be') {
id = location.pathname.slice('/'.length)
}
if (id) {
return {
source: {
provider: 'YouTube',
id
},
picture: await this.getPicture(id)
}
}
},
getPicture: async (id) => {
for (const sizeName of PICTURE_SIZE_NAMES) {
try {
const url = getPictureSizeURL(id, sizeName)
return {
type: 'image/jpeg',
sizes: [{
url,
...(await getImageSize(url))
}]
}
} catch (error) {
console.error(error)
}
}
throw new Error(`No picture found for YouTube video ${id}`)
},
getEmbeddedVideoURL(id, options = {}) {
return `https://www.youtube.com/embed/${id}`
}
}
const getPictureSizeURL = (id, sizeName) => `https://img.youtube.com/vi/${id}/${sizeName}.jpg`
Utility image.js:
// Gets image size.
// Returns a `Promise`.
function getImageSize(url)
{
return new Promise((resolve, reject) =>
{
const image = new Image()
image.onload = () => resolve({ width: image.width, height: image.height })
image.onerror = reject
image.src = url
})
}
Utility url.js:
// Only on client side.
export function parseURL(url)
{
const link = document.createElement('a')
link.href = url
return link
}
export function parseQueryString(queryString)
{
return queryString.split('&').reduce((query, part) =>
{
const [key, value] = part.split('=')
query[decodeURIComponent(key)] = decodeURIComponent(value)
return query
},
{})
}
document .click function for touch device
can you use jqTouch or jquery mobile ? there it's much easier to handle touch events. If not then you need to simulate click on touch device, follow this articles:
Spring's overriding bean
An example from official spring manual:
<bean id="inheritedTestBean" abstract="true"
class="org.springframework.beans.TestBean">
<property name="name" value="parent"/>
<property name="age" value="1"/>
</bean>
<bean id="inheritsWithDifferentClass"
class="org.springframework.beans.DerivedTestBean"
parent="inheritedTestBean" init-method="initialize">
<property name="name" value="override"/>
<!-- the age property value of 1 will be inherited from parent -->
</bean>
Is that what you was looking for? Updated link
How to save an HTML5 Canvas as an image on a server?
I've worked on something similar.
Had to convert canvas Base64-encoded image to Uint8Array Blob.
function b64ToUint8Array(b64Image) {
var img = atob(b64Image.split(',')[1]);
var img_buffer = [];
var i = 0;
while (i < img.length) {
img_buffer.push(img.charCodeAt(i));
i++;
}
return new Uint8Array(img_buffer);
}
var b64Image = canvas.toDataURL('image/jpeg');
var u8Image = b64ToUint8Array(b64Image);
var formData = new FormData();
formData.append("image", new Blob([ u8Image ], {type: "image/jpg"}));
var xhr = new XMLHttpRequest();
xhr.open("POST", "/api/upload", true);
xhr.send(formData);
Align labels in form next to input
You can also try using flex-box
<head><style>
body {
color:white;
font-family:arial;
font-size:1.2em;
}
form {
margin:0 auto;
padding:20px;
background:#444;
}
.input-group {
margin-top:10px;
width:60%;
display:flex;
justify-content:space-between;
flex-wrap:wrap;
}
label, input {
flex-basis:100px;
}
</style></head>
<body>
<form>
<div class="wrapper">
<div class="input-group">
<label for="user_name">name:</label>
<input type="text" id="user_name">
</div>
<div class="input-group">
<label for="user_pass">Password:</label>
<input type="password" id="user_pass">
</div>
</div>
</form>
</body>
</html>
Changing background color of selected item in recyclerview
I made this implementation in kotlin I thing is not very efficient but works ivIsSelected is a ImageView that represent in my case a check mark
var selectedItems = mutableListOf<Int>(-1)
override fun onBindViewHolder(holder: ContactViewHolder, position: Int) {
// holder.setData(ContactViewModel, position) // I'm passing this to the ViewHolder
holder.itemView.setBackgroundColor(Color.WHITE)
holder.itemView.ivIsSelected.visibility = INVISIBLE
selectedItems.forEach {
if (it == position) {
holder.itemView.setBackgroundColor(Color.argb(45, 0, 255, 43))
holder.itemView.ivIsSelected.visibility = VISIBLE
}
}
holder.itemView.setOnClickListener { it ->
it.setBackgroundColor(Color.BLUE)
selectedItems.add(position)
selectedItems.forEach { selectedItem -> // this forEach is required to refresh all the list
notifyItemChanged(selectedItem)
}
}
}
What’s the difference between “{}” and “[]” while declaring a JavaScript array?
In JavaScript Arrays and Objects are actually very similar, although on the outside they can look a bit different.
For an array:
var array = [];
array[0] = "hello";
array[1] = 5498;
array[536] = new Date();
As you can see arrays in JavaScript can be sparse (valid indicies don't have to be consecutive) and they can contain any type of variable! That's pretty convenient.
But as we all know JavaScript is strange, so here are some weird bits:
array["0"] === "hello"; // This is true
array["hi"]; // undefined
array["hi"] = "weird"; // works but does not save any data to array
array["hi"]; // still undefined!
This is because everything in JavaScript is an Object (which is why you can also create an array using new Array()). As a result every index in an array is turned into a string and then stored in an object, so an array is just an object that doesn't allow anyone to store anything with a key that isn't a positive integer.
So what are Objects?
Objects in JavaScript are just like arrays but the "index" can be any string.
var object = {};
object[0] = "hello"; // OK
object["hi"] = "not weird"; // OK
You can even opt to not use the square brackets when working with objects!
console.log(object.hi); // Prints 'not weird'
object.hi = "overwriting 'not weird'";
You can go even further and define objects like so:
var newObject = {
a: 2,
};
newObject.a === 2; // true
Replace a value in a data frame based on a conditional (`if`) statement
As the data you show are factors, it complicates things a little bit. @diliop's Answer approaches the problem by converting to nm to a character variable. To get back to the original factors a further step is required.
An alternative is to manipulate the levels of the factor in place.
> lev <- with(junk, levels(nm))
> lev[lev == "B"] <- "b"
> junk2 <- within(junk, levels(nm) <- lev)
> junk2
nm val
1 A a
2 b b
3 C c
4 D d
5 A e
6 b f
7 C g
8 D h
9 A i
10 b j
11 C k
12 D l
That is quite simple and I often forget that there is a replacement function for levels().
Edit: As noted by @Seth in the comments, this can be done in a one-liner, without loss of clarity:
within(junk, levels(nm)[levels(nm) == "B"] <- "b")
How to download an entire directory and subdirectories using wget?
You can use this in a shell:
wget -r -nH --cut-dirs=7 --reject="index.html*" \
http://abc.tamu.edu/projects/tzivi/repository/revisions/2/raw/tzivi/
The Parameters are:
-r recursively download
-nH (--no-host-directories) cuts out hostname
--cut-dirs=X (cuts out X directories)
How do I check CPU and Memory Usage in Java?
Java's Runtime object can report the JVM's memory usage. For CPU consumption you'll have to use an external utility, like Unix's top or Windows Process Manager.
Apple Mach-O Linker Error when compiling for device
My fix for my same problem: Adding the "other linker flags" in "Project" and not in "Targets". So, I moved it to "Targets", it shouldn't be in "Project".
ImportError: No module named PyQt4.QtCore
I was having the same error - ImportError: No module named PyQt4.QtGui. Instead of running your python file (which uses PyQt) on the terminal as -
python file_name.py
Run it with sudo privileges -
sudo python file_name.py
This worked for me!
How to test an Internet connection with bash?
Ping your default gateway:
#!/bin/bash
ping -q -w 1 -c 1 `ip r | grep default | cut -d ' ' -f 3` > /dev/null && echo ok || echo error
What is the default maximum heap size for Sun's JVM from Java SE 6?
To answer this question it's critical whether the Java VM is in CLIENT or SERVER mode. You can specify "-client" or "-server" options. Otherwise java uses internal rules; basically win32 is always client and Linux is always server, but see the table here:
http://docs.oracle.com/javase/6/docs/technotes/guides/vm/server-class.html
Sun/Oracle jre6u18 doc says re client: the VM gets 1/2 of physical memory if machine has <= 192MB; 1/4 of memory if machine has <= 1Gb; max 256Mb. In my test on a 32bit WindowsXP system with 2Gb phys mem, Java allocated 256Mb, which agrees with the doc.
Sun/Oracle jre6u18 doc says re server: same as client, then adds confusing language: for 32bit JVM the default max is 1Gb, and for 64 bit JVM the default is 32Gb. In my test on a 64bit linux machine with 8Gb physical, Java allocates 2Gb, which is 1/4 of physical; on a 64bit linux machine with 128Gb physical Java allocates 32Gb, again 1/4 of physical.
Thanks to this SO post for guiding me:
Hive: how to show all partitions of a table?
CLI has some limit when ouput is displayed. I suggest to export output into local file:
$hive -e 'show partitions table;' > partitions
What is a word boundary in regex, does \b match hyphen '-'?
A word boundary can occur in one of three positions:
- Before the first character in the string, if the first character is a word character.
- After the last character in the string, if the last character is a word character.
- Between two characters in the string, where one is a word character and the other is not a word character.
Word characters are alpha-numeric; a minus sign is not. Taken from Regex Tutorial.
How to uninstall with msiexec using product id guid without .msi file present
msiexec.exe /x "{588A9A11-1E20-4B91-8817-2D36ACBBBF9F}" /q
error: request for member '..' in '..' which is of non-class type
If you want to declare a new substance with no parameter (knowing that the object have default parameters) don't write
type substance1();
but
type substance;
Is there an easy way to convert Android Application to IPad, IPhone
In the box is working on being able to convert android projects to iOS
JavaFX Panel inside Panel auto resizing
Also see here
@FXML
private void mnuUserLevel_onClick(ActionEvent event) {
FXMLLoader loader = new FXMLLoader(getClass().getResource("DBedit.fxml"));
loader.setController(new DBeditEntityUserlevel());
try {
Node n = (Node)loader.load();
AnchorPane.setTopAnchor(n, 0.0);
AnchorPane.setRightAnchor(n, 0.0);
AnchorPane.setLeftAnchor(n, 0.0);
AnchorPane.setBottomAnchor(n, 0.0);
mainContent.getChildren().setAll(n);
} catch (IOException e){
System.out.println(e.getMessage());
}
}
The scenario is to load a child fxml into parent AnchorPane. To make the child to stretch in accords to its parent use AnChorPane.setxxxAnchor command.
how to count the total number of lines in a text file using python
here is how you can do it through list comprehension, but this will waste a little bit of your computer's memory as line.strip() has been called twice.
with open('textfile.txt') as file:
lines =[
line.strip()
for line in file
if line.strip() != '']
print("number of lines = {}".format(len(lines)))
How to disable all <input > inside a form with jQuery?
To disable all form, as easy as write:
jQuery 1.6+
$("#form :input").prop("disabled", true);
jQuery 1.5 and below
$("#form :input").attr('disabled','disabled');
Sum function in VBA
Function is not a property/method from range.
If you want to sum values then use the following:
Range("A1").Value = Application.Sum(Range(Cells(2, 1), Cells(3, 2)))
EDIT:
if you want the formula then use as follows:
Range("A1").Formula = "=SUM(" & Range(Cells(2, 1), Cells(3, 2)).Address(False, False) & ")"
'The two false after Adress is to define the address as relative (A2:B3).
'If you omit the parenthesis clause or write True instead, you can set the address
'as absolute ($A$2:$B$3).
In case you are allways going to use the same range address then you can use as Rory sugested:
Range("A1").Formula ="=Sum(A2:B3)"
how to iterate through dictionary in a dictionary in django template?
If you pass a variable data (dictionary type) as context to a template, then you code should be:
{% for key, value in data.items %}
<p>{{ key }} : {{ value }}</p>
{% endfor %}
java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient
starting the hive metastore service worked for me. First, set up the database for hive metastore:
$ hive --service metastore
Second, run the following commands:
$ schematool -dbType mysql -initSchema
$ schematool -dbType mysql -info
https://cwiki.apache.org/confluence/display/Hive/Hive+Schema+Tool
matplotlib colorbar for scatter
If you're looking to scatter by two variables and color by the third, Altair can be a great choice.
Creating the dataset
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
df = pd.DataFrame(40*np.random.randn(10, 3), columns=['A', 'B','C'])
Altair plot
from altair import *
Chart(df).mark_circle().encode(x='A',y='B', color='C').configure_cell(width=200, height=150)
Plot
Style bottom Line in Android
A Simple solution :
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:bottom="-1dp"
android:left="-1dp"
android:right="-1dp"
android:top="-1dp">
<shape android:shape="rectangle">
<solid android:color="#AARRGGBB" />
<stroke
android:width="5dp"
android:color="@android:color/red"
android:dashWidth="10dp"
android:dashGap="12dp" />
</shape>
</item>
</layer-list>
And finally we have something like that :)
How to get input textfield values when enter key is pressed in react js?
Use onKeyDown event, and inside that check the key code of the key pressed by user. Key code of Enter key is 13, check the code and put the logic there.
Check this example:
class CartridgeShell extends React.Component {_x000D_
_x000D_
constructor(props) {_x000D_
super(props);_x000D_
this.state = {value:''}_x000D_
_x000D_
this.handleChange = this.handleChange.bind(this);_x000D_
this.keyPress = this.keyPress.bind(this);_x000D_
} _x000D_
_x000D_
handleChange(e) {_x000D_
this.setState({ value: e.target.value });_x000D_
}_x000D_
_x000D_
keyPress(e){_x000D_
if(e.keyCode == 13){_x000D_
console.log('value', e.target.value);_x000D_
// put the login here_x000D_
}_x000D_
}_x000D_
_x000D_
render(){_x000D_
return(_x000D_
<input value={this.state.value} onKeyDown={this.keyPress} onChange={this.handleChange} fullWidth={true} />_x000D_
)_x000D_
}_x000D_
}_x000D_
_x000D_
ReactDOM.render(<CartridgeShell/>, document.getElementById('app'))<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
_x000D_
_x000D_
<div id = 'app' />Note: Replace the input element by Material-Ui TextField and define the other properties also.
How to use SQL Order By statement to sort results case insensitive?
You can just convert everything to lowercase for the purposes of sorting:
SELECT * FROM NOTES ORDER BY LOWER(title);
If you want to make sure that the uppercase ones still end up ahead of the lowercase ones, just add that as a secondary sort:
SELECT * FROM NOTES ORDER BY LOWER(title), title;
How to initialize a static array?
Nope, no difference. It's just syntactic sugar. Arrays.asList(..) creates an additional list.
Oracle: how to add minutes to a timestamp?
All of the other answers are basically right but I don't think anyone's directly answered your original question.
Assuming that "date_and_time" in your example is a column with type DATE or TIMESTAMP, I think you just need to change this:
to_char(date_and_time + (.000694 * 31))
to this:
to_char(date_and_time + (.000694 * 31), 'DD-MON-YYYY HH24:MI')
It sounds like your default date format uses the "HH" code for the hour, not "HH24".
Also, I think your constant term is both confusing and imprecise. I guess what you did is calculate that (.000694) is about the value of a minute, and you are multiplying it by the number of minutes you want to add (31 in the example, although you said 30 in the text).
I would also start with a day and divide it into the units you want within your code. In this case, (1/48) would be 30 minutes; or if you wanted to break it up for clarity, you could write ( (1/24) * (1/2) ).
This would avoid rounding errors (except for those inherent in floating point which should be meaningless here) and is clearer, at least to me.
Angular 1 - get current URL parameters
In your route configuration you typically define a route like,
.when('somewhere/:param1/:param2')
You can then either get the route in the resolve object by using $route.current.params
or in a controller, $routeParams. In either case the parameters is extracted using the mapping of the route, so param1 can be accessed by $routeParams.param1 in the controller.
Edit: Also note that the mapping has to be exact
/some/folder/:param1
Will only match a single parameter.
/some/folder/:param1/:param2
Will only match two parameters.
This is a bit different then most dynamic server side routes. For example NodeJS (Express) route mapping where you can supply only a single route with X number of parameters.
Python 3.6 install win32api?
Information provided by @Gord
As of September 2019 pywin32 is now available from PyPI and installs the latest version (currently version 224). This is done via the pip command
pip install pywin32
If you wish to get an older version the sourceforge link below would probably have the desired version, if not you can use the command, where xxx is the version you require, e.g. 224
pip install pywin32==xxx
This differs to the pip command below as that one uses pypiwin32 which currently installs an older (namely 223)
Browsing the docs I see no reason for these commands to work for all python3.x versions, I am unsure on python2.7 and below so you would have to try them and if they do not work then the solutions below will work.
Probably now undesirable solutions but certainly still valid as of September 2019
There is no version of specific version ofwin32api. You have to get the pywin32module which currently cannot be installed via pip. It is only available from this link at the moment.
https://sourceforge.net/projects/pywin32/files/pywin32/Build%20220/
The install does not take long and it pretty much all done for you. Just make sure to get the right version of it depending on your python version :)
EDIT
Since I posted my answer there are other alternatives to downloading the win32api module.
It is now available to download through pip using this command;
pip install pypiwin32
Also it can be installed from this GitHub repository as provided in comments by @Heath
Key value pairs using JSON
I see what you are trying to ask and I think this is the simplest answer to what you are looking for, given you might not know how many key pairs your are being sent.
Simple Key Pair JSON structure
var data = {
'XXXXXX' : '100.0',
'YYYYYYY' : '200.0',
'ZZZZZZZ' : '500.0',
}
Usage JavaScript code to access the key pairs
for (var key in data)
{ if (!data.hasOwnProperty(key))
{ continue; }
console.log(key + ' -> ' + data[key]);
};
Console output should look like this
XXXXXX -> 100.0
YYYYYYY -> 200.0
ZZZZZZZ -> 500.0
Here is a JSFiddle to show how it works.
How to "scan" a website (or page) for info, and bring it into my program?
My answer won't probably be useful to the writer of this question (I am 8 months late so not the right timing I guess) but I think it will probably be useful for many other developers that might come across this answer.
Today, I just released (in the name of my company) an HTML to POJO complete framework that you can use to map HTML to any POJO class with simply some annotations. The library itself is quite handy and features many other things all the while being very pluggable. You can have a look to it right here : https://github.com/whimtrip/jwht-htmltopojo
How to use : Basics
Imagine we need to parse the following html page :
<html>
<head>
<title>A Simple HTML Document</title>
</head>
<body>
<div class="restaurant">
<h1>A la bonne Franquette</h1>
<p>French cuisine restaurant for gourmet of fellow french people</p>
<div class="location">
<p>in <span>London</span></p>
</div>
<p>Restaurant n*18,190. Ranked 113 out of 1,550 restaurants</p>
<div class="meals">
<div class="meal">
<p>Veal Cutlet</p>
<p rating-color="green">4.5/5 stars</p>
<p>Chef Mr. Frenchie</p>
</div>
<div class="meal">
<p>Ratatouille</p>
<p rating-color="orange">3.6/5 stars</p>
<p>Chef Mr. Frenchie and Mme. French-Cuisine</p>
</div>
</div>
</div>
</body>
</html>
Let's create the POJOs we want to map it to :
public class Restaurant {
@Selector( value = "div.restaurant > h1")
private String name;
@Selector( value = "div.restaurant > p:nth-child(2)")
private String description;
@Selector( value = "div.restaurant > div:nth-child(3) > p > span")
private String location;
@Selector(
value = "div.restaurant > p:nth-child(4)"
format = "^Restaurant n\*([0-9,]+). Ranked ([0-9,]+) out of ([0-9,]+) restaurants$",
indexForRegexPattern = 1,
useDeserializer = true,
deserializer = ReplacerDeserializer.class,
preConvert = true,
postConvert = false
)
// so that the number becomes a valid number as they are shown in this format : 18,190
@ReplaceWith(value = ",", with = "")
private Long id;
@Selector(
value = "div.restaurant > p:nth-child(4)"
format = "^Restaurant n\*([0-9,]+). Ranked ([0-9,]+) out of ([0-9,]+) restaurants$",
// This time, we want the second regex group and not the first one anymore
indexForRegexPattern = 2,
useDeserializer = true,
deserializer = ReplacerDeserializer.class,
preConvert = true,
postConvert = false
)
// so that the number becomes a valid number as they are shown in this format : 18,190
@ReplaceWith(value = ",", with = "")
private Integer rank;
@Selector(value = ".meal")
private List<Meal> meals;
// getters and setters
}
And now the Meal class as well :
public class Meal {
@Selector(value = "p:nth-child(1)")
private String name;
@Selector(
value = "p:nth-child(2)",
format = "^([0-9.]+)\/5 stars$",
indexForRegexPattern = 1
)
private Float stars;
@Selector(
value = "p:nth-child(2)",
// rating-color custom attribute can be used as well
attr = "rating-color"
)
private String ratingColor;
@Selector(
value = "p:nth-child(3)"
)
private String chefs;
// getters and setters.
}
We provided some more explanations on the above code on our github page.
For the moment, let's see how to scrap this.
private static final String MY_HTML_FILE = "my-html-file.html";
public static void main(String[] args) {
HtmlToPojoEngine htmlToPojoEngine = HtmlToPojoEngine.create();
HtmlAdapter<Restaurant> adapter = htmlToPojoEngine.adapter(Restaurant.class);
// If they were several restaurants in the same page,
// you would need to create a parent POJO containing
// a list of Restaurants as shown with the meals here
Restaurant restaurant = adapter.fromHtml(getHtmlBody());
// That's it, do some magic now!
}
private static String getHtmlBody() throws IOException {
byte[] encoded = Files.readAllBytes(Paths.get(MY_HTML_FILE));
return new String(encoded, Charset.forName("UTF-8"));
}
Another short example can be found here
Hope this will help someone out there!
npm start error with create-react-app
add environment variables in windows
- C:\WINDOWS\System32
- C:\Program Files\nodejs
- C:\Program Files\nodejs\node_modules\npm\bin
- C:\WINDOWS\System32\WindowsPowerShell\v1.0
- C:\Users{your system name without curly braces}\AppData\Roaming\npm
these 5 are must in path.
and use the latest version of node.js
Authentication plugin 'caching_sha2_password' cannot be loaded
For those using Docker or Docker Compose, I experienced this error because I didn't set my MySQL image version. Docker will automatically attempt to get the latest version which is 8.
I set MySQL to 5.7 and rebuilt the image and it worked as normal:
version: '2'
services:
db:
image: mysql:5.7
Bootstrap Dropdown with Hover
This will help you make your own hover class for bootstrap:
CSS:
/* Hover dropdown */
.hover_drop_down.input-group-btn ul.dropdown-menu{margin-top: 0px;}/*To avoid unwanted close*/
.hover_drop_down.btn-group ul.dropdown-menu{margin-top:2px;}/*To avoid unwanted close*/
.hover_drop_down:hover ul.dropdown-menu{
display: block;
}
Margins are set to avoid unwanted close and they are optional.
HTML:
<div class="btn-group hover_drop_down">
<button type="button" class="btn btn-default" data-toggle="dropdown"></button>
<ul class="dropdown-menu" role="menu">
...
</ul>
</div>
Don't forget to remove the button attribute data-toggle="dropdown" if you want to remove onclick open, and this also will work when input is append with dropdown.
HTML: Changing colors of specific words in a string of text
You can also make a class:
<span class="mychangecolor"> I am in yellow color!!!!!!</span>
then in a css file do:
.mychangecolor{ color:#ff5 /* it changes to yellow */ }
How do I create a MessageBox in C#?
Also you can use a MessageBox with OKCancel options, but it requires many codes.
The if block is for OK, the else block is for Cancel. Here is the code:
if (MessageBox.Show("Are you sure you want to do this?", "Question", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK)
{
MessageBox.Show("You pressed OK!");
}
else
{
MessageBox.Show("You pressed Cancel!");
}
You can also use a MessageBox with YesNo options:
if (MessageBox.Show("Are you sure want to doing this?", "Question", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
MessageBox.Show("You are pressed Yes!");
}
else
{
MessageBox.Show("You are pressed No!");
}
No plot window in matplotlib
The code snippet below works on both Eclipse and the Python shell:
import numpy as np
import matplotlib.pyplot as plt
# Come up with x and y
x = np.arange(0, 5, 0.1)
y = np.sin(x)
# Just print x and y for fun
print x
print y
# Plot the x and y and you are supposed to see a sine curve
plt.plot(x, y)
# Without the line below, the figure won't show
plt.show()
How to choose between Hudson and Jenkins?
From the Jenkins website, http://jenkins-ci.org, the following sums it up.
In a nutshell Jenkins CI is the leading open-source continuous integration server. Built with Java, it provides over 300 plugins to support building and testing virtually any project.
Oracle now owns the Hudson trademark, but has licensed it under the Eclipse EPL. Jenkins is on the MIT license. Both Hudson and Jenkins are open-source. Based on the combination of who you work for and personal preference for open-source, the decision is straightforward IMHO.
Hope this was helpful.
Integer ASCII value to character in BASH using printf
Here's yet another way to convert 65 into A (via octal):
help printf # in Bash
man bash | less -Ip '^[[:blank:]]*printf'
printf "%d\n" '"A'
printf "%d\n" "'A"
printf '%b\n' "$(printf '\%03o' 65)"
To search in man bash for \' use (though futile in this case):
man bash | less -Ip "\\\'" # press <n> to go through the matches
Unable to call the built in mb_internal_encoding method?
mbstring is a "non-default" extension, that is not enabled by default ; see this page of the manual :
Installation
mbstring is a non-default extension. This means it is not enabled by default. You must explicitly enable the module with the configure option. See the Install section for details
So, you might have to enable that extension, modifying the php.ini file (and restarting Apache, so your modification is taken into account)
I don't use CentOS, but you may have to install the extension first, using something like this (see this page, for instance, which seems to give a solution) :
yum install php-mbstring
(The package name might be a bit different ; so, use yum search to get it :-) )
Swap two variables without using a temporary variable
C# 7 introduced tuples which enables swapping two variables without a temporary one:
int a = 10;
int b = 2;
(a, b) = (b, a);
This assigns b to a and a to b.
Soft keyboard open and close listener in an activity in Android
when keyboard show
rootLayout.getHeight() < rootLayout.getRootView().getHeight() - getStatusBarHeight()
is true,else hide
Css pseudo classes input:not(disabled)not:[type="submit"]:focus
You have a few typos in your select. It should be: input:not([disabled]):not([type="submit"]):focus
See this jsFiddle for a proof of concept. On a sidenote, if I removed the "background-color" property, then the box shadow no longer works. Not sure why.
How to return a value from pthread threads in C?
Here is a correct solution. In this case tdata is allocated in the main thread, and there is a space for the thread to place its result.
#include <pthread.h>
#include <stdio.h>
typedef struct thread_data {
int a;
int b;
int result;
} thread_data;
void *myThread(void *arg)
{
thread_data *tdata=(thread_data *)arg;
int a=tdata->a;
int b=tdata->b;
int result=a+b;
tdata->result=result;
pthread_exit(NULL);
}
int main()
{
pthread_t tid;
thread_data tdata;
tdata.a=10;
tdata.b=32;
pthread_create(&tid, NULL, myThread, (void *)&tdata);
pthread_join(tid, NULL);
printf("%d + %d = %d\n", tdata.a, tdata.b, tdata.result);
return 0;
}
Laravel Eloquent "WHERE NOT IN"
The dynamic way of implement whereNotIn:
$users = User::where('status',0)->get();
foreach ($users as $user) {
$data[] = $user->id;
}
$available = User::orderBy('name', 'DEC')->whereNotIn('id', $data)->get();
Error: Could not create the Java Virtual Machine Mac OSX Mavericks
if you tried running java with -version argument, and even though the problem could not be solved by any means, then you might have installed many java versions, like JDK 1.8 and JDK 1.7 at the same time.
So try uninstalling all other versions other than the one you need, then set the JAVA_HOMEpath variable for that JDK remaining, and you're done.
Auto-increment on partial primary key with Entity Framework Core
Annotate the property like below
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
To use identity columns for all value-generated properties on a new model, simply place the following in your context's OnModelCreating():
builder.ForNpgsqlUseIdentityColumns();
This will create make all keys and other properties which have .ValueGeneratedOnAdd() have Identity by default. You can use ForNpgsqlUseIdentityAlwaysColumns() to have Identity always, and you can also specify identity on a property-by-property basis with UseNpgsqlIdentityColumn() and UseNpgsqlIdentityAlwaysColumn().
Where does R store packages?
This is documented in the 'R Installation and Administration' manual that came with your installation.
On my Linux box:
R> .libPaths()
[1] "/usr/local/lib/R/site-library" "/usr/lib/R/site-library"
[3] "/usr/lib/R/library"
R>
meaning that the default path is the first of these. You can override that via an argument to both install.packages() (from inside R) or R CMD INSTALL (outside R).
You can also override by setting the R_LIBS_USER variable.
How do I output lists as a table in Jupyter notebook?
I recently used prettytable for rendering a nice ASCII table. It's similar to the postgres CLI output.
import pandas as pd
from prettytable import PrettyTable
data = [[1,2,3],[4,5,6],[7,8,9]]
df = pd.DataFrame(data, columns=['one', 'two', 'three'])
def generate_ascii_table(df):
x = PrettyTable()
x.field_names = df.columns.tolist()
for row in df.values:
x.add_row(row)
print(x)
return x
generate_ascii_table(df)
Output:
+-----+-----+-------+
| one | two | three |
+-----+-----+-------+
| 1 | 2 | 3 |
| 4 | 5 | 6 |
| 7 | 8 | 9 |
+-----+-----+-------+
Can't get Python to import from a different folder
My preferred way is to have __init__.py on every directory that contains modules that get used by other modules, and in the entry point, override sys.path as below:
def get_path(ss):
return os.path.join(os.path.dirname(__file__), ss)
sys.path += [
get_path('Server'),
get_path('Models')
]
This makes the files in specified directories visible for import, and I can import user from Server.py.
What are the correct version numbers for C#?
C# 1.0 - Visual Studio .NET 2002
Classes
Structs
Interfaces
Events
Properties
Delegates
Expressions
Statements
Attributes
Literals
C# 1.2 - Visual Studio .NET 2003
Dispose in foreach
foreach over string specialization
C# 2 - Visual Studio 2005
Generics
Partial types
Anonymous methods
Iterators
Nullable types
Getter/setter separate accessibility
Method group conversions (delegates)
Static classes
Delegate inference
C# 3 - Visual Studio 2008
Implicitly typed local variables
Object and collection initializers
Auto-Implemented properties
Anonymous types
Extension methods
Query expressions
Lambda expression
Expression trees
Partial methods
C# 4 - Visual Studio 2010
Dynamic binding
Named and optional arguments
Co- and Contra-variance for generic delegates and interfaces
Embedded interop types ("NoPIA")
C# 5 - Visual Studio 2012
Asynchronous methods
Caller info attributes
C# 6 - Visual Studio 2015
Draft Specification online
Compiler-as-a-service (Roslyn)
Import of static type members into namespace
Exception filters
Await in catch/finally blocks
Auto property initializers
Default values for getter-only properties
Expression-bodied members
Null propagator (null-conditional operator, succinct null checking)
String interpolation
nameof operator
Dictionary initializer
C# 7.0 - Visual Studio 2017
Out variables
Pattern matching
Tuples
Deconstruction
Discards
Local Functions
Binary Literals
Digit Separators
Ref returns and locals
Generalized async return types
More expression-bodied members
Throw expressions
C# 7.1 - Visual Studio 2017 version 15.3
Async main
Default expressions
Reference assemblies
Inferred tuple element names
Pattern-matching with generics
C# 7.2 - Visual Studio 2017 version 15.5
Span and ref-like types
In parameters and readonly references
Ref conditional
Non-trailing named arguments
Private protected accessibility
Digit separator after base specifier
C# 7.3 - Visual Studio 2017 version 15.7
System.Enum, System.Delegate and unmanaged constraints.
Ref local re-assignment: Ref locals and ref parameters can now be reassigned with the ref assignment operator (= ref).
Stackalloc initializers: Stack-allocated arrays can now be initialized, e.g. Span<int> x = stackalloc[] { 1, 2, 3 };.
Indexing movable fixed buffers: Fixed buffers can be indexed into without first being pinned.
Custom fixed statement: Types that implement a suitable GetPinnableReference can be used in a fixed statement.
Improved overload candidates: Some overload resolution candidates can be ruled out early, thus reducing ambiguities.
Expression variables in initializers and queries: Expression variables like out var and pattern variables are allowed in field initializers, constructor initializers and LINQ queries.
Tuple comparison: Tuples can now be compared with == and !=.
Attributes on backing fields: Allows [field: …] attributes on an auto-implemented property to target its backing field.
C# 8.0 - .NET Core 3.0 and Visual Studio 2019 version 16.3
Nullable reference types: express nullability intent on reference types with ?, notnull constraint and annotations attributes in APIs, the compiler will use those to try and detect possible null values being dereferenced or passed to unsuitable APIs.
Default interface members: interfaces can now have members with default implementations, as well as static/private/protected/internal members except for state (ie. no fields).
Recursive patterns: positional and property patterns allow testing deeper into an object, and switch expressions allow for testing multiple patterns and producing corresponding results in a compact fashion.
Async streams: await foreach and await using allow for asynchronous enumeration and disposal of IAsyncEnumerable<T> collections and IAsyncDisposable resources, and async-iterator methods allow convenient implementation of such asynchronous streams.
Enhanced using: a using declaration is added with an implicit scope and using statements and declarations allow disposal of ref structs using a pattern.
Ranges and indexes: the i..j syntax allows constructing System.Range instances, the ^k syntax allows constructing System.Index instances, and those can be used to index/slice collections.
Null-coalescing assignment: ??= allows conditionally assigning when the value is null.
Static local functions: local functions modified with static cannot capture this or local variables, and local function parameters now shadow locals in parent scopes.
Unmanaged generic structs: generic struct types that only have unmanaged fields are now considered unmanaged (ie. they satisfy the unmanaged constraint).
Readonly members: individual members can now be marked as readonly to indicate and enforce that they do not modify instance state.
Stackalloc in nested contexts: stackalloc expressions are now allowed in more expression contexts.
Alternative interpolated verbatim strings: @$"..." strings are recognized as interpolated verbatim strings just like $@"...".
Obsolete on property accessors: property accessors can now be individually marked as obsolete.
Permit t is null on unconstrained type parameter
[source] : https://github.com/dotnet/csharplang/blob/master/Language-Version-History.md
What does if __name__ == "__main__": do?
Consider:
print __name__
The output for the above is __main__.
if __name__ == "__main__":
print "direct method"
The above statement is true and prints "direct method". Suppose if they imported this class in another class it doesn't print "direct method" because, while importing, it will set __name__ equal to "first model name".
Javascript: How to pass a function with string parameters as a parameter to another function
One way would be to just escape the quotes properly:
<input type="button" value="click" id="mybtn"
onclick="myfunction('/myController/myAction',
'myfuncionOnOK(\'/myController2/myAction2\',
\'myParameter2\');',
'myfuncionOnCancel(\'/myController3/myAction3\',
\'myParameter3\');');">
In this case, though, I think a better way to handle this would be to wrap the two handlers in anonymous functions:
<input type="button" value="click" id="mybtn"
onclick="myfunction('/myController/myAction',
function() { myfuncionOnOK('/myController2/myAction2',
'myParameter2'); },
function() { myfuncionOnCancel('/myController3/myAction3',
'myParameter3'); });">
And then, you could call them from within myfunction like this:
function myfunction(url, onOK, onCancel)
{
// Do whatever myfunction would normally do...
if (okClicked)
{
onOK();
}
if (cancelClicked)
{
onCancel();
}
}
That's probably not what myfunction would actually look like, but you get the general idea. The point is, if you use anonymous functions, you have a lot more flexibility, and you keep your code a lot cleaner as well.
How to split a string at the first `/` (slash) and surround part of it in a `<span>`?
use this
<div id="date">23/05/2013</div>
<script type="text/javascript">
$(document).ready(function(){
var x = $("#date").text();
x.text(x.substring(0, 2) + '<br />'+x.substring(3));
});
</script>
Division in Python 2.7. and 3.3
In Python 2.x, make sure to have at least one operand of your division in float. Multiple ways you may achieve this as the following examples:
20. / 15
20 / float(15)
Angular2 - Http POST request parameters
If anyone is struggling with angular version 4+ (mine was 4.3.6). This was the sample code which worked for me.
First add the required imports
import { Http, Headers, Response, URLSearchParams } from '@angular/http';
Then for the api function. It's a login sample which can be changed as per your needs.
login(username: string, password: string) {
var headers = new Headers();
headers.append('Content-Type', 'application/x-www-form-urlencoded');
let urlSearchParams = new URLSearchParams();
urlSearchParams.append('email', username);
urlSearchParams.append('password', password);
let body = urlSearchParams.toString()
return this.http.post('http://localhost:3000/api/v1/login', body, {headers: headers})
.map((response: Response) => {
// login successful if user.status = success in the response
let user = response.json();
console.log(user.status)
if (user && "success" == user.status) {
// store user details and jwt token in local storage to keep user logged in between page refreshes
localStorage.setItem('currentUser', JSON.stringify(user.data));
}
});
}
What is the difference between Class.getResource() and ClassLoader.getResource()?
All these answers around here, as well as the answers in this question, suggest that loading absolute URLs, like "/foo/bar.properties" treated the same by class.getResourceAsStream(String) and class.getClassLoader().getResourceAsStream(String). This is NOT the case, at least not in my Tomcat configuration/version (currently 7.0.40).
MyClass.class.getResourceAsStream("/foo/bar.properties"); // works!
MyClass.class.getClassLoader().getResourceAsStream("/foo/bar.properties"); // does NOT work!
Sorry, I have absolutely no satisfying explanation, but I guess that tomcat does dirty tricks and his black magic with the classloaders and cause the difference. I always used class.getResourceAsStream(String) in the past and haven't had any problems.
PS: I also posted this over here
Can promises have multiple arguments to onFulfilled?
Great question, and great answer by Benjamin, Kris, et al - many thanks!
I'm using this in a project and have created a module based on Benjamin Gruenwald's code. It's available on npmjs:
npm i -S promise-spread
Then in your code, do
require('promise-spread');
If you're using a library such as any-promise
var Promise = require('any-promise');
require('promise-spread')(Promise);
Maybe others find this useful, too!
The multi-part identifier could not be bound
If this error happens in an UPDATE, double-check the JOIN on the table with the column/field that is causing the error.
In my case this was due to the lack of the JOIN itself, which generated the same error due to an unknown field (as Andriy pointed out).
How to measure elapsed time in Python?
Here is a tiny timer class that returns "hh:mm:ss" string:
class Timer:
def __init__(self):
self.start = time.time()
def restart(self):
self.start = time.time()
def get_time_hhmmss(self):
end = time.time()
m, s = divmod(end - self.start, 60)
h, m = divmod(m, 60)
time_str = "%02d:%02d:%02d" % (h, m, s)
return time_str
Usage:
# Start timer
my_timer = Timer()
# ... do something
# Get time string:
time_hhmmss = my_timer.get_time_hhmmss()
print("Time elapsed: %s" % time_hhmmss )
# ... use the timer again
my_timer.restart()
# ... do something
# Get time:
time_hhmmss = my_timer.get_time_hhmmss()
# ... etc
How to set background color of HTML element using css properties in JavaScript
In general, CSS properties are converted to JavaScript by making them camelCase without any dashes. So background-color becomes backgroundColor.
function setColor(element, color)
{
element.style.backgroundColor = color;
}
// where el is the concerned element
var el = document.getElementById('elementId');
setColor(el, 'green');
Server certificate verification failed: issuer is not trusted
during command line works. I'm using Ant to commit an artifact after build completes. Experienced the same issue... Manually excepting the cert did not work (Jenkins is funny that way). Add these options to your svn command:
--non-interactive
--trust-server-cert
How to pick a new color for each plotted line within a figure in matplotlib?
matplotlib 1.5+
You can use axes.set_prop_cycle (example).
matplotlib 1.0-1.4
You can use axes.set_color_cycle (example).
matplotlib 0.x
You can use Axes.set_default_color_cycle.
Join between tables in two different databases?
SELECT <...>
FROM A.tableA JOIN B.tableB
Pythonic way to add datetime.date and datetime.time objects
It's in the python docs.
import datetime
datetime.datetime.combine(datetime.date(2011, 1, 1),
datetime.time(10, 23))
returns
datetime.datetime(2011, 1, 1, 10, 23)
How to check if all of the following items are in a list?
I like these two because they seem the most logical, the latter being shorter and probably fastest (shown here using set literal syntax which has been backported to Python 2.7):
all(x in {'a', 'b', 'c'} for x in ['a', 'b'])
# or
{'a', 'b'}.issubset({'a', 'b', 'c'})
Google Authenticator available as a public service?
Theres: https://www.gauthify.com that offers it as a service
jQuery - Redirect with post data
Why dont just create a form with some hidden inputs and submit it using jQuery? Should work :)
Convert row names into first column
Moved my comment into an answer per suggestion above:
You don't need extra packages, here's a one-liner:
d <- cbind(rownames(d), data.frame(d, row.names=NULL))
Fast ceiling of an integer division in C / C++
This works for positive or negative numbers:
q = x / y + ((x % y != 0) ? !((x > 0) ^ (y > 0)) : 0);
If there is a remainder, checks to see if x and y are of the same sign and adds 1 accordingly.
'xmlParseEntityRef: no name' warnings while loading xml into a php file
This is in deed due to characters messing around with the data. Using htmlentities($yourText) worked for me (I had html code inside the xml document). See http://uk3.php.net/htmlentities.
How to access a preexisting collection with Mongoose?
Here's an abstraction of Will Nathan's answer if anyone just wants an easy copy-paste add-in function:
function find (name, query, cb) {
mongoose.connection.db.collection(name, function (err, collection) {
collection.find(query).toArray(cb);
});
}
simply do find(collection_name, query, callback); to be given the result.
for example, if I have a document { a : 1 } in a collection 'foo' and I want to list its properties, I do this:
find('foo', {a : 1}, function (err, docs) {
console.dir(docs);
});
//output: [ { _id: 4e22118fb83406f66a159da5, a: 1 } ]
How can I plot with 2 different y-axes?
update: Copied material that was on the R wiki at http://rwiki.sciviews.org/doku.php?id=tips:graphics-base:2yaxes, link now broken: also available from the wayback machine
Two different y axes on the same plot
(some material originally by Daniel Rajdl 2006/03/31 15:26)
Please note that there are very few situations where it is appropriate to use two different scales on the same plot. It is very easy to mislead the viewer of the graphic. Check the following two examples and comments on this issue (example1, example2 from Junk Charts), as well as this article by Stephen Few (which concludes “I certainly cannot conclude, once and for all, that graphs with dual-scaled axes are never useful; only that I cannot think of a situation that warrants them in light of other, better solutions.”) Also see point #4 in this cartoon ...
If you are determined, the basic recipe is to create your first plot, set par(new=TRUE) to prevent R from clearing the graphics device, creating the second plot with axes=FALSE (and setting xlab and ylab to be blank – ann=FALSE should also work) and then using axis(side=4) to add a new axis on the right-hand side, and mtext(...,side=4) to add an axis label on the right-hand side. Here is an example using a little bit of made-up data:
set.seed(101)
x <- 1:10
y <- rnorm(10)
## second data set on a very different scale
z <- runif(10, min=1000, max=10000)
par(mar = c(5, 4, 4, 4) + 0.3) # Leave space for z axis
plot(x, y) # first plot
par(new = TRUE)
plot(x, z, type = "l", axes = FALSE, bty = "n", xlab = "", ylab = "")
axis(side=4, at = pretty(range(z)))
mtext("z", side=4, line=3)
twoord.plot() in the plotrix package automates this process, as does doubleYScale() in the latticeExtra package.
Another example (adapted from an R mailing list post by Robert W. Baer):
## set up some fake test data
time <- seq(0,72,12)
betagal.abs <- c(0.05,0.18,0.25,0.31,0.32,0.34,0.35)
cell.density <- c(0,1000,2000,3000,4000,5000,6000)
## add extra space to right margin of plot within frame
par(mar=c(5, 4, 4, 6) + 0.1)
## Plot first set of data and draw its axis
plot(time, betagal.abs, pch=16, axes=FALSE, ylim=c(0,1), xlab="", ylab="",
type="b",col="black", main="Mike's test data")
axis(2, ylim=c(0,1),col="black",las=1) ## las=1 makes horizontal labels
mtext("Beta Gal Absorbance",side=2,line=2.5)
box()
## Allow a second plot on the same graph
par(new=TRUE)
## Plot the second plot and put axis scale on right
plot(time, cell.density, pch=15, xlab="", ylab="", ylim=c(0,7000),
axes=FALSE, type="b", col="red")
## a little farther out (line=4) to make room for labels
mtext("Cell Density",side=4,col="red",line=4)
axis(4, ylim=c(0,7000), col="red",col.axis="red",las=1)
## Draw the time axis
axis(1,pretty(range(time),10))
mtext("Time (Hours)",side=1,col="black",line=2.5)
## Add Legend
legend("topleft",legend=c("Beta Gal","Cell Density"),
text.col=c("black","red"),pch=c(16,15),col=c("black","red"))
Similar recipes can be used to superimpose plots of different types – bar plots, histograms, etc..
Python write line by line to a text file
Well, the problem you have is wrong line ending/encoding for notepad. Notepad uses Windows' line endings - \r\n and you use \n.
How do I encode and decode a base64 string?
Encode
public static string Base64Encode(string plainText) {
var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);
return System.Convert.ToBase64String(plainTextBytes);
}
Decode
public static string Base64Decode(string base64EncodedData) {
var base64EncodedBytes = System.Convert.FromBase64String(base64EncodedData);
return System.Text.Encoding.UTF8.GetString(base64EncodedBytes);
}
Understanding Chrome network log "Stalled" state
DevTools: [network] explain empty bars preceeding request
Investigated further and have identified that there's no significant difference between our Stalled and Queueing ranges. Both are calculated from the delta's of other timestamps, rather than provided from netstack or renderer.
Currently, if we're waiting for a socket to become available:
- we'll call it stalled if some proxy negotiation happened
- we'll call it queuing if no proxy/ssl work was required.
How do I print colored output with Python 3?
I use the colors module. Clone the git repository, run the setup.py and you're good. You can then print text with colors very easily like this:
import colors
print(colors.red('this is red'))
print(colors.green('this is green'))
This works on the command line, but might need further configuration for IDLE.
SELECT inside a COUNT
You don't really need a sub-select:
SELECT a, COUNT(*) AS b,
SUM( CASE WHEN c = 'const' THEN 1 ELSE 0 END ) as d,
from t group by a order by b desc
How do I iterate and modify Java Sets?
You can do what you want if you use an iterator object to go over the elements in your set. You can remove them on the go an it's ok. However removing them while in a for loop (either "standard", of the for each kind) will get you in trouble:
Set<Integer> set = new TreeSet<Integer>();
set.add(1);
set.add(2);
set.add(3);
//good way:
Iterator<Integer> iterator = set.iterator();
while(iterator.hasNext()) {
Integer setElement = iterator.next();
if(setElement==2) {
iterator.remove();
}
}
//bad way:
for(Integer setElement:set) {
if(setElement==2) {
//might work or might throw exception, Java calls it indefined behaviour:
set.remove(setElement);
}
}
As per @mrgloom's comment, here are more details as to why the "bad" way described above is, well... bad :
Without getting into too much details about how Java implements this, at a high level, we can say that the "bad" way is bad because it is clearly stipulated as such in the Java docs:
https://docs.oracle.com/javase/8/docs/api/java/util/ConcurrentModificationException.html
stipulate, amongst others, that (emphasis mine):
"For example, it is not generally permissible for one thread to modify a Collection while another thread is iterating over it. In general, the results of the iteration are undefined under these circumstances. Some Iterator implementations (including those of all the general purpose collection implementations provided by the JRE) may choose to throw this exception if this behavior is detected" (...)
"Note that this exception does not always indicate that an object has been concurrently modified by a different thread. If a single thread issues a sequence of method invocations that violates the contract of an object, the object may throw this exception. For example, if a thread modifies a collection directly while it is iterating over the collection with a fail-fast iterator, the iterator will throw this exception."
To go more into details: an object that can be used in a forEach loop needs to implement the "java.lang.Iterable" interface (javadoc here). This produces an Iterator (via the "Iterator" method found in this interface), which is instantiated on demand, and will contain internally a reference to the Iterable object from which it was created. However, when an Iterable object is used in a forEach loop, the instance of this iterator is hidden to the user (you cannot access it yourself in any way).
This, coupled with the fact that an Iterator is pretty stateful, i.e. in order to do its magic and have coherent responses for its "next" and "hasNext" methods it needs that the backing object is not changed by something else than the iterator itself while it's iterating, makes it so that it will throw an exception as soon as it detects that something changed in the backing object while it is iterating over it.
Java calls this "fail-fast" iteration: i.e. there are some actions, usually those that modify an Iterable instance (while an Iterator is iterating over it). The "fail" part of the "fail-fast" notion refers to the ability of an Iterator to detect when such "fail" actions happen. The "fast" part of the "fail-fast" (and, which in my opinion should be called "best-effort-fast"), will terminate the iteration via ConcurrentModificationException as soon as it can detect that a "fail" action has happen.
Java Compare Two List's object values?
First, implement the MyData.equals(Object o) and MyData.hashCode() methods.
Once you implemented the equals method, you can iterate over the lists as follows:
if(ListA == null && ListB == null)
return false;
if(ListA == null && ListB != null)
return true;
if(ListA != null && ListB == null)
return true;
int max = ListA.size() > ListB.size() ? ListA.size() : ListB.size();
for(int i = 0; i < max; i++) {
myData1 = ListA.get(i);
myData2 = ListB.get(i);
if(!myData1.equals(myData2)) {
return true;
}
}
return false;
Staging Deleted files
to Add all ready deleted files
git status -s | grep -E '^ D' | cut -d ' ' -f3 | xargs git add --all
thank check to make sure
git status
you should be good to go
Alert after page load
There are three ways.
The first is to put the script tag on the bottom of the page:
<body>
<!--Body content-->
<script type="text/javascript">
alert('<%: TempData["Resultat"]%>');
</script>
</body>
The second way is to create an onload event:
<head>
<script type="text/javascript">
window.onload = function(){//window.addEventListener('load',function(){...}); (for Netscape) and window.attachEvent('onload',function(){...}); (for IE and Opera) also work
alert('<%: TempData["Resultat"]%>');
}
</script>
</head>
It will execute a function when the window loads.
Finally, the third way is to create a readystatechange event and check the current document.readystate:
<head>
<script type="text/javascript">
document.onreadystatechange = function(){//window.addEventListener('readystatechange',function(){...}); (for Netscape) and window.attachEvent('onreadystatechange',function(){...}); (for IE and Opera) also work
if(document.readyState=='loaded' || document.readyState=='complete')
alert('<%: TempData["Resultat"]%>');
}
</script>
</head>
Node.js, can't open files. Error: ENOENT, stat './path/to/file'
Here the code to use your app.js
input specifies file name
res.download(__dirname+'/'+input);
How to analyze disk usage of a Docker container
After 1.13.0, Docker includes a new command docker system df to show docker disk usage.
$ docker system df
TYPE TOTAL ACTIVE SIZE RECLAIMABLE
Images 5 1 2.777 GB 2.647 GB (95%)
Containers 1 1 0 B 0B
Local Volumes 4 1 3.207 GB 2.261 (70%)
To show more detailed information on space usage:
$ docker system df --verbose
How to update UI from another thread running in another class
I am going to throw you a curve ball here. If I have said it once I have said it a hundred times. Marshaling operations like Invoke or BeginInvoke are not always the best methods for updating the UI with worker thread progress.
In this case it usually works better to have the worker thread publish its progress information to a shared data structure that the UI thread then polls at regular intervals. This has several advantages.
- It breaks the tight coupling between the UI and worker thread that
Invokeimposes. - The UI thread gets to dictate when the UI controls get updated...the way it should be anyway when you really think about it.
- There is no risk of overrunning the UI message queue as would be the case if
BeginInvokewere used from the worker thread. - The worker thread does not have to wait for a response from the UI thread as would be the case with
Invoke. - You get more throughput on both the UI and worker threads.
InvokeandBeginInvokeare expensive operations.
So in your calcClass create a data structure that will hold the progress information.
public class calcClass
{
private double percentComplete = 0;
public double PercentComplete
{
get
{
// Do a thread-safe read here.
return Interlocked.CompareExchange(ref percentComplete, 0, 0);
}
}
public testMethod(object input)
{
int count = 1000;
for (int i = 0; i < count; i++)
{
Thread.Sleep(10);
double newvalue = ((double)i + 1) / (double)count;
Interlocked.Exchange(ref percentComplete, newvalue);
}
}
}
Then in your MainWindow class use a DispatcherTimer to periodically poll the progress information. Configure the DispatcherTimer to raise the Tick event on whatever interval is most appropriate for your situation.
public partial class MainWindow : Window
{
public void YourDispatcherTimer_Tick(object sender, EventArgs args)
{
YourProgressBar.Value = calculation.PercentComplete;
}
}
How to check for valid email address?
The Python standard library comes with an e-mail parsing function: email.utils.parseaddr().
It returns a two-tuple containing the real name and the actual address parts of the e-mail:
>>> from email.utils import parseaddr
>>> parseaddr('[email protected]')
('', '[email protected]')
>>> parseaddr('Full Name <[email protected]>')
('Full Name', '[email protected]')
>>> parseaddr('"Full Name with quotes and <[email protected]>" <[email protected]>')
('Full Name with quotes and <[email protected]>', '[email protected]')
And if the parsing is unsuccessful, it returns a two-tuple of empty strings:
>>> parseaddr('[invalid!email]')
('', '')
An issue with this parser is that it's accepting of anything that is considered as a valid e-mail address for RFC-822 and friends, including many things that are clearly not addressable on the wide Internet:
>>> parseaddr('invalid@example,com') # notice the comma
('', 'invalid@example')
>>> parseaddr('invalid-email')
('', 'invalid-email')
So, as @TokenMacGuy put it, the only definitive way of checking an e-mail address is to send an e-mail to the expected address and wait for the user to act on the information inside the message.
However, you might want to check for, at least, the presence of an @-sign on the second tuple element, as @bvukelic suggests:
>>> '@' in parseaddr("invalid-email")[1]
False
If you want to go a step further, you can install the dnspython project and resolve the mail servers for the e-mail domain (the part after the '@'), only trying to send an e-mail if there are actual MX servers:
>>> from dns.resolver import query
>>> domain = 'foo@[email protected]'.rsplit('@', 1)[-1]
>>> bool(query(domain, 'MX'))
True
>>> query('example.com', 'MX')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
[...]
dns.resolver.NoAnswer
>>> query('not-a-domain', 'MX')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
[...]
dns.resolver.NXDOMAIN
You can catch both NoAnswer and NXDOMAIN by catching dns.exception.DNSException.
And Yes, foo@[email protected] is a syntactically valid address. Only the last @ should be considered for detecting where the domain part starts.
phpmyadmin #1045 Cannot log in to the MySQL server. after installing mysql command line client
Go to phpMyAdmin Directory of your Localhost Software Like Xampp, Mamp or others. Then change the host from localhost to 127.0.0.1 and change the port to 3307 . After that go to your data directory and delete all error log files except ibdata1 which is important file to hold your created database table link. Finaly restart mysql.I think your problem will be solved.
how to check for datatype in node js- specifically for integer
I think of two ways to test for the type of a value:
Method 1:
You can use the isNaN javascript method, which determines if a value is NaN or not. But because in your case you are testing a numerical value converted to string, Javascript is trying to guess the type of the value and converts it to the number 5 which is not NaN. That's why if you console.log out the result, you will be surprised that the code:
if (isNaN(i)) {
console.log('This is not number');
}
will not return anything. For this reason a better alternative would be the method 2.
Method 2:
You may use javascript typeof method to test the type of a variable or value
if (typeof i != "number") {
console.log('This is not number');
}
Notice that i'm using double equal operator, because in this case the type of the value is a string but Javascript internally will convert to Number.
A more robust method to force the value to numerical type is to use Number.isNaN which is part of new Ecmascript 6 (Harmony) proposal, hence not widespread and fully supported by different vendors.
Get GPS location from the web browser
Use this, and you will find all informations at http://www.w3schools.com/html/html5_geolocation.asp
<script>
var x = document.getElementById("demo");
function getLocation() {
if (navigator.geolocation) {
navigator.geolocation.getCurrentPosition(showPosition);
} else {
x.innerHTML = "Geolocation is not supported by this browser.";
}
}
function showPosition(position) {
x.innerHTML = "Latitude: " + position.coords.latitude +
"<br>Longitude: " + position.coords.longitude;
}
</script>
Open window in JavaScript with HTML inserted
Here's how to do it with an HTML Blob, so that you have control over the entire HTML document:
https://codepen.io/trusktr/pen/mdeQbKG?editors=0010
This is the code, but StackOverflow blocks the window from being opened (see the codepen example instead):
const winHtml = `<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
<title>Window with Blob</title>_x000D_
</head>_x000D_
<body>_x000D_
<h1>Hello from the new window!</h1>_x000D_
</body>_x000D_
</html>`;_x000D_
_x000D_
const winUrl = URL.createObjectURL(_x000D_
new Blob([winHtml], { type: "text/html" })_x000D_
);_x000D_
_x000D_
const win = window.open(_x000D_
winUrl,_x000D_
"win",_x000D_
`width=800,height=400,screenX=200,screenY=200`_x000D_
);Eclipse error: 'Failed to create the Java Virtual Machine'
This may work:
Open eclipse.ini file and paste below lines at the end of the lines.
-vmargs
-Xms40m
-Xmx512m
-XX:MaxPermSize=256m
Is there a naming convention for git repositories?
Maybe it is just my Java and C background showing, but I prefer CamelCase (CapCase) over punctuation in the name. My workgroup uses such names, probably to match the names of the app or service the repository contains.
How to change the port number for Asp.Net core app?
Go to your program.cs file add UseUrs method to set your url, make sure you don't use a reserved url or port
public class Program
{
public static void Main(string[] args)
{
BuildWebHost(args).Run();
}
public static IWebHost BuildWebHost(string[] args) =>
WebHost.CreateDefaultBuilder(args)
.UseStartup<Startup>()
// params string[] urls
.UseUrls(urls: "http://localhost:10000")
.Build();
}
Get text of the selected option with jQuery
$(document).ready(function() {
$('select#select_2').change(function() {
var selectedText = $(this).find('option:selected').text();
alert(selectedText);
});
});
Use String.split() with multiple delimiters
For two char sequence as delimeters "AND" and "OR" this should be worked. Don't forget to trim while using.
String text ="ISTANBUL AND NEW YORK AND PARIS OR TOKYO AND MOSCOW";
String[] cities = text.split("AND|OR");
Result : cities = {"ISTANBUL ", " NEW YORK ", " PARIS ", " TOKYO ", " MOSCOW"}
How to replace (or strip) an extension from a filename in Python?
Try os.path.splitext it should do what you want.
import os
print os.path.splitext('/home/user/somefile.txt')[0]+'.jpg'
member names cannot be the same as their enclosing type C#
Method names which are same as the class name are called constructors. Constructors do not have a return type. So correct as:
private Flow()
{
X = x;
Y = y;
}
Or rename the function as:
private void DoFlow()
{
X = x;
Y = y;
}
Though the whole code does not make any sense to me.
Angular - Use pipes in services and components
If you don't want do 'new myPipe()' because you're injecting dependencies to pipe, you can inject in component like provider and use without new.
Example:
// In your component...
import { Component, OnInit } from '@angular/core';
import { myPipe} from './pipes';
@Component({
selector: 'my-component',
template: '{{ data }}',
providers: [ myPipe ]
})
export class MyComponent() implements OnInit {
data = 'some data';
constructor(private myPipe: myPipe) {}
ngOnInit() {
this.data = this.myPipe.transform(this.data);
}
}
How to preserve insertion order in HashMap?
HashMap is unordered per the second line of the documentation:
This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time.
Perhaps you can do as aix suggests and use a LinkedHashMap, or another ordered collection. This link can help you find the most appropriate collection to use.
How to stop tracking and ignore changes to a file in Git?
The problem may be caused by the order of operation. If you modified the .gitignore first, then git rm --cached xxx,you may have to continue to encounter this problem.
Correct solution:
- git rm --cached xxx
- modified the .gitignore
Order invariant!
The .gitignore reload after modification!
Merge some list items in a Python List
just a variation
alist=["a", "b", "c", "d", "e", 0, "g"]
alist[3:6] = [''.join(map(str,alist[3:6]))]
print alist
Generate PDF from Swagger API documentation
Handy way: Using Browser Printing/Preview
- Hide editor pane
- Print Preview (I used firefox, others also fine)
- Change its page setup and print to pdf
NameError: uninitialized constant (rails)
In my case, I named a column name type and tried to set its value as UNPREPARED. And I got an error message like this:
Caused by: api_1 | NameError: uninitialized constant UNPREPARED
In rails, column type is reserved:
ActiveRecord::SubclassNotFound: The single-table inheritance mechanism failed to locate the subclass: 'UNPREPARED'. This error is raised because the column 'type' is reserved for storing the class in case of inheritance. Pl ease rename this column if you didn't intend it to be used for storing the inheritance class or overwrite Food.inheritance_column to use another column for that information
javascript filter array multiple conditions
const users = [{
name: 'John',
email: '[email protected]',
age: 25,
address: 'USA'
},
{
name: 'Tom',
email: '[email protected]',
age: 35,
address: 'England'
},
{
name: 'Mark',
email: '[email protected]',
age: 28,
address: 'England'
}
];
const filteredUsers = users.filter(({ name, age }) => name === 'Tom' && age === 35)
console.log(filteredUsers)
Is it possible to sort a ES6 map object?
Unfortunately, not really implemented in ES6. You have this feature with OrderedMap.sort() from ImmutableJS or _.sortBy() from Lodash.
How can I set the 'backend' in matplotlib in Python?
For new comers,
matplotlib.pyplot.switch_backend(newbackend)
How do I do a simple 'Find and Replace" in MsSQL?
If you are working with SQL Server 2005 or later there is also a CLR library available at http://www.sqlsharp.com/ that provides .NET implementations of string and RegEx functions which, depending on your volume and type of data may be easier to use and in some cases the .NET string manipulation functions can be more efficient than T-SQL ones.
Save PHP array to MySQL?
Just use the serialize PHP function:
<?php
$myArray = array('1', '2');
$seralizedArray = serialize($myArray);
?>
However, if you are using simple arrays like that you might as well use implode and explode.Use a blank array instead of new.
Why is Node.js single threaded?
Node.js was created explicitly as an experiment in async processing. The theory was that doing async processing on a single thread could provide more performance and scalability under typical web loads than the typical thread-based implementation.
And you know what? In my opinion that theory's been borne out. A node.js app that isn't doing CPU intensive stuff can run thousands more concurrent connections than Apache or IIS or other thread-based servers.
The single threaded, async nature does make things complicated. But do you honestly think it's more complicated than threading? One race condition can ruin your entire month! Or empty out your thread pool due to some setting somewhere and watch your response time slow to a crawl! Not to mention deadlocks, priority inversions, and all the other gyrations that go with multithreading.
In the end, I don't think it's universally better or worse; it's different, and sometimes it's better and sometimes it's not. Use the right tool for the job.
Is it a bad practice to use an if-statement without curly braces?
The problem with the first version is that if you go back and add a second statement to the if or else clauses without remembering to add the curly braces, your code will break in unexpected and amusing ways.
Maintainability-wise, it's always smarter to use the second form.
EDIT: Ned points this out in the comments, but it's worth linking to here, too, I think. This is not just some ivory-tower hypothetical bullshit: https://www.imperialviolet.org/2014/02/22/applebug.html
JSON to string variable dump
Here is the code I use. You should be able to adapt it to your needs.
function process_test_json() {
var jsonDataArr = { "Errors":[],"Success":true,"Data":{"step0":{"collectionNameStr":"dei_ideas_org_Private","url_root":"http:\/\/192.168.1.128:8500\/dei-ideas_org\/","collectionPathStr":"C:\\ColdFusion8\\wwwroot\\dei-ideas_org\\wwwrootchapter0-2\\verity_collections\\","writeVerityLastFileNameStr":"C:\\ColdFusion8\\wwwroot\\dei-ideas_org\\wwwroot\\chapter0-2\\VerityLastFileName.txt","doneFlag":false,"state_dbrec":{},"errorMsgStr":"","fileroot":"C:\\ColdFusion8\\wwwroot\\dei-ideas_org\\wwwroot"}}};
var htmlStr= "<h3 class='recurse_title'>[jsonDataArr] struct is</h3> " + recurse( jsonDataArr );
alert( htmlStr );
$( document.createElement('div') ).attr( "class", "main_div").html( htmlStr ).appendTo('div#out');
$("div#outAsHtml").text( $("div#out").html() );
}
function recurse( data ) {
var htmlRetStr = "<ul class='recurseObj' >";
for (var key in data) {
if (typeof(data[key])== 'object' && data[key] != null) {
htmlRetStr += "<li class='keyObj' ><strong>" + key + ":</strong><ul class='recurseSubObj' >";
htmlRetStr += recurse( data[key] );
htmlRetStr += '</ul ></li >';
} else {
htmlRetStr += ("<li class='keyStr' ><strong>" + key + ': </strong>"' + data[key] + '"</li >' );
}
};
htmlRetStr += '</ul >';
return( htmlRetStr );
}
</script>
</head><body>
<button onclick="process_test_json()" >Run process_test_json()</button>
<div id="out"></div>
<div id="outAsHtml"></div>
</body>
CSS: 100% width or height while keeping aspect ratio?
Not to jump into an old issue, but...
#container img {
max-width:100%;
height:auto !important;
}
Even though this is not proper as you use the !important override on the height, if you're using a CMS like WordPress that sets the height and width for you, this works well.
imagecreatefromjpeg and similar functions are not working in PHP
For php 7 on Ubuntu:
sudo apt-get install php7.0-gd
How to view .img files?
you could use either PowerISO or WinRAR
Java HTTP Client Request with defined timeout
Op later stated they were using Apache Commons HttpClient 3.0.1
HttpClient client = new HttpClient();
client.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
client.getHttpConnectionManager().getParams().setSoTimeout(5000);
Suppress/ print without b' prefix for bytes in Python 3
Use decode:
print(curses.version.decode())
# 2.2
What does "Table does not support optimize, doing recreate + analyze instead" mean?
OPTIMIZE TABLE works fine with InnoDB engine according to the official support article : http://dev.mysql.com/doc/refman/5.5/en/optimize-table.html
You'll notice that optimize InnoDB tables will rebuild table structure and update index statistics (something like ALTER TABLE).
Keep in mind that this message could be an informational mention only and the very important information is the status of your query : just OK !
mysql> OPTIMIZE TABLE foo;
+----------+----------+----------+-------------------------------------------------------------------+
| Table | Op | Msg_type | Msg_text |
+----------+----------+----------+-------------------------------------------------------------------+
| test.foo | optimize | note | Table does not support optimize, doing recreate + analyze instead |
| test.foo | optimize | status | OK |
+----------+----------+----------+-------------------------------------------------------------------+
Difference between spring @Controller and @RestController annotation
THE new @RestController annotation in Spring4+, which marks the class as a controller where every method returns a domain object instead of a view. It’s shorthand for @Controller and @ResponseBody rolled together.
Add floating point value to android resources/values
We can also use it for the guideline of the constraint layout.
Create integer.xml file and add into
<item name="guideline_button_top" type="integer" format="float">0.60</item>
Use from a layout.xml file
app:layout_constraintGuide_percent="@integer/guideline_button_top"
Default value for field in Django model
Set editable to False and default to your default value.
http://docs.djangoproject.com/en/stable/ref/models/fields/#editable
b = models.CharField(max_length=7, default='0000000', editable=False)
Also, your id field is unnecessary. Django will add it automatically.
How to implement an STL-style iterator and avoid common pitfalls?
http://www.cplusplus.com/reference/std/iterator/ has a handy chart that details the specs of § 24.2.2 of the C++11 standard. Basically, the iterators have tags that describe the valid operations, and the tags have a hierarchy. Below is purely symbolic, these classes don't actually exist as such.
iterator {
iterator(const iterator&);
~iterator();
iterator& operator=(const iterator&);
iterator& operator++(); //prefix increment
reference operator*() const;
friend void swap(iterator& lhs, iterator& rhs); //C++11 I think
};
input_iterator : public virtual iterator {
iterator operator++(int); //postfix increment
value_type operator*() const;
pointer operator->() const;
friend bool operator==(const iterator&, const iterator&);
friend bool operator!=(const iterator&, const iterator&);
};
//once an input iterator has been dereferenced, it is
//undefined to dereference one before that.
output_iterator : public virtual iterator {
reference operator*() const;
iterator operator++(int); //postfix increment
};
//dereferences may only be on the left side of an assignment
//once an output iterator has been dereferenced, it is
//undefined to dereference one before that.
forward_iterator : input_iterator, output_iterator {
forward_iterator();
};
//multiple passes allowed
bidirectional_iterator : forward_iterator {
iterator& operator--(); //prefix decrement
iterator operator--(int); //postfix decrement
};
random_access_iterator : bidirectional_iterator {
friend bool operator<(const iterator&, const iterator&);
friend bool operator>(const iterator&, const iterator&);
friend bool operator<=(const iterator&, const iterator&);
friend bool operator>=(const iterator&, const iterator&);
iterator& operator+=(size_type);
friend iterator operator+(const iterator&, size_type);
friend iterator operator+(size_type, const iterator&);
iterator& operator-=(size_type);
friend iterator operator-(const iterator&, size_type);
friend difference_type operator-(iterator, iterator);
reference operator[](size_type) const;
};
contiguous_iterator : random_access_iterator { //C++17
}; //elements are stored contiguously in memory.
You can either specialize std::iterator_traits<youriterator>, or put the same typedefs in the iterator itself, or inherit from std::iterator (which has these typedefs). I prefer the second option, to avoid changing things in the std namespace, and for readability, but most people inherit from std::iterator.
struct std::iterator_traits<youriterator> {
typedef ???? difference_type; //almost always ptrdiff_t
typedef ???? value_type; //almost always T
typedef ???? reference; //almost always T& or const T&
typedef ???? pointer; //almost always T* or const T*
typedef ???? iterator_category; //usually std::forward_iterator_tag or similar
};
Note the iterator_category should be one of std::input_iterator_tag, std::output_iterator_tag, std::forward_iterator_tag, std::bidirectional_iterator_tag, or std::random_access_iterator_tag, depending on which requirements your iterator satisfies. Depending on your iterator, you may choose to specialize std::next, std::prev, std::advance, and std::distance as well, but this is rarely needed. In extremely rare cases you may wish to specialize std::begin and std::end.
Your container should probably also have a const_iterator, which is a (possibly mutable) iterator to constant data that is similar to your iterator except it should be implicitly constructable from a iterator and users should be unable to modify the data. It is common for its internal pointer to be a pointer to non-constant data, and have iterator inherit from const_iterator so as to minimize code duplication.
My post at Writing your own STL Container has a more complete container/iterator prototype.
What is the largest possible heap size with a 64-bit JVM?
In theory everything is possible but reality you find the numbers much lower than you might expect. I have been trying to address huge spaces on servers often and found that even though a server can have huge amounts of memory it surprised me that most software actually never can address it in real scenario's simply because the cpu's are not fast enough to really address them. Why would you say right ?! . Timings thats the endless downfall of every enormous machine which i have worked on. So i would advise to not go overboard by addressing huge amounts just because you can, but use what you think could be used. Actual values are often much lower than what you expected. Ofcourse non of us really uses hp 9000 systems at home and most of you actually ever will go near the capacity of your home system ever. For instance most users do not have more than 16 Gb of memory in their system. Ofcourse some of the casual gamers use work stations for a game once a month but i bet that is a very small percentage. So coming down to earth means i would address on a 8 Gb 64 bit system not much more than 512 mb for heapspace or if you go overboard try 1 Gb. I am pretty sure its even with these numbers pure overkill. I have constant monitored the memory usage during gaming to see if the addressing would make any difference but did not notice any difference at all when i addressed much lower values or larger ones. Even on the server/workstations there was no visible change in performance no matter how large i set the values. That does not say some jave users might be able to make use of more space addressed, but this far i have not seen any of the applications needing so much ever. Ofcourse i assume that their would be a small difference in performance if java instances would run out of enough heapspace to work with. This far i have not found any of it at all, however lack of real installed memory showed instant drops of performance if you set too much heapspace. When you have a 4 Gb system you run quickly out of heapspace and then you will see some errors and slowdowns because people address too much space which actually is not free in the system so the os starts to address drive space to make up for the shortage hence it starts to swap.
Difference between "read commited" and "repeatable read"
Simply the answer according to my reading and understanding to this thread and @remus-rusanu answer is based on this simple scenario:
There are two transactions A and B. Transaction B is reading Table X Transaction A is writing in table X Transaction B is reading again in Table X.
- ReadUncommitted: Transaction B can read uncommitted data from Transaction A and it could see different rows based on B writing. No lock at all
- ReadCommitted: Transaction B can read ONLY committed data from Transaction A and it could see different rows based on COMMITTED only B writing. could we call it Simple Lock?
- RepeatableRead: Transaction B will read the same data (rows) whatever Transaction A is doing. But Transaction A can change other rows. Rows level Block
- Serialisable: Transaction B will read the same rows as before and Transaction A cannot read or write in the table. Table-level Block
- Snapshot: every Transaction has its own copy and they are working on it. Each one has its own view
Jquery UI datepicker. Disable array of Dates
$('input').datepicker({
beforeShowDay: function(date){
var string = jQuery.datepicker.formatDate('yy-mm-dd', date);
return [ array.indexOf(string) == -1 ]
}
});
Remove all occurrences of char from string
You can use str = str.replace("X", ""); as mentioned before and you will be fine. For your information '' is not an empty (or a valid) character but '\0' is.
So you could use str = str.replace('X', '\0'); instead.
Execute a SQL Stored Procedure and process the results
My Stored Procedure Requires 2 Parameters and I needed my function to return a datatable here is 100% working code
Please make sure that your procedure return some rows
Public Shared Function Get_BillDetails(AccountNumber As String) As DataTable
Try
Connection.Connect()
debug.print("Look up account number " & AccountNumber)
Dim DP As New SqlDataAdapter("EXEC SP_GET_ACCOUNT_PAYABLES_GROUP '" & AccountNumber & "' , '" & 08/28/2013 &"'", connection.Con)
Dim DST As New DataSet
DP.Fill(DST)
Return DST.Tables(0)
Catch ex As Exception
Return Nothing
End Try
End Function
How to switch to other branch in Source Tree to commit the code?
- Go to the log view (to be able to go here go to View -> log view).
- Double click on the line with the branch label stating that branch. Automatically, it will switch branch. (A prompt will dropdown and say switching branch.)
- If you have two or more branches on the same line, it will ask you via prompt which branch you want to switch. Choose the specific branch from the dropdown and click ok.
To determine which branch you are now on, look at the side bar, under BRANCHES, you are in the branch that is in BOLD LETTERS.
Concatenate string with field value in MySQL
MySQL uses CONCAT() to concatenate strings
SELECT * FROM tableOne
LEFT JOIN tableTwo
ON tableTwo.query = CONCAT('category_id=', tableOne.category_id)
How to get a function name as a string?
my_function.func_name
There are also other fun properties of functions. Type dir(func_name) to list them. func_name.func_code.co_code is the compiled function, stored as a string.
import dis
dis.dis(my_function)
will display the code in almost human readable format. :)
Python setup.py develop vs install
Another thing that people may find useful when using the develop method is the --user option to install without sudo. Ex:
python setup.py develop --user
instead of
sudo python setup.py develop
remove double quotes from Json return data using Jquery
You can simple try String(); to remove the quotes.
Refer the first example here: https://www.w3schools.com/jsref/jsref_string.asp
Thank me later.
PS: TO MODs: don't mistaken me for digging the dead old question. I faced this issue today and I came across this post while searching for the answer and I'm just posting the answer.
Angular JS break ForEach
You can use this:
var count = 0;
var arr = [0,1,2];
for(var i in arr){
if(count == 1) break;
//console.log(arr[i]);
}
How do I create a user with the same privileges as root in MySQL/MariaDB?
% mysql --user=root mysql
CREATE USER 'monty'@'localhost' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost' WITH GRANT OPTION;
CREATE USER 'monty'@'%' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%' WITH GRANT OPTION;
CREATE USER 'admin'@'localhost';
GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';
CREATE USER 'dummy'@'localhost';
FLUSH PRIVILEGES;
Java how to sort a Linked List?
If you'd like to know how to sort a linked list without using standard Java libraries, I'd suggest looking at different algorithms yourself. Examples here show how to implement an insertion sort, another StackOverflow post shows a merge sort, and ehow even gives some examples on how to create a custom compare function in case you want to further customize your sort.
How to stop flask application without using ctrl-c
My method can be proceeded via bash terminal/console
1) run and get the process number
$ ps aux | grep yourAppKeywords
2a) kill the process
$ kill processNum
2b) kill the process if above not working
$ kill -9 processNum
Find difference between timestamps in seconds in PostgreSQL
SELECT (cast(timestamp_1 as bigint) - cast(timestamp_2 as bigint)) FROM table;
In case if someone is having an issue using extract.
Uncaught ReferenceError: $ is not defined error in jQuery
Include the jQuery file first:
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script type="text/javascript" src="./javascript.js"></script>
<script
src="http://maps.googleapis.com/maps/api/js?key=AIzaSyCJnj2nWoM86eU8Bq2G4lSNz3udIkZT4YY&sensor=false">
</script>
How do I deserialize a JSON string into an NSDictionary? (For iOS 5+)
NSData *data = [strChangetoJSON dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *jsonResponse = [NSJSONSerialization JSONObjectWithData:data
options:kNilOptions
error:&error];
For example you have a NSString with special characters in NSString strChangetoJSON.
Then you can convert that string to JSON response using above code.
Implementing a HashMap in C
The best approach depends on the expected key distribution and number of collisions. If relatively few collisions are expected, it really doesn't matter which method is used. If lots of collisions are expected, then which to use depends on the cost of rehashing or probing vs. manipulating the extensible bucket data structure.
But here is source code example of An Hashmap Implementation in C
postgresql: INSERT INTO ... (SELECT * ...)
Here's an alternate solution, without using dblink.
Suppose B represents the source database and A represents the target database: Then,
Copy table from source DB to target DB:
pg_dump -t <source_table> <source_db> | psql <target_db>Open psql prompt, connect to target_db, and use a simple
insert:psql # \c <target_db>; # INSERT INTO <target_table>(id, x, y) SELECT id, x, y FROM <source_table>;At the end, delete the copy of source_table that you created in target_table.
# DROP TABLE <source_table>;
MS SQL 2008 - get all table names and their row counts in a DB
SELECT sc.name +'.'+ ta.name TableName
,SUM(pa.rows) RowCnt
FROM sys.tables ta
INNER JOIN sys.partitions pa
ON pa.OBJECT_ID = ta.OBJECT_ID
INNER JOIN sys.schemas sc
ON ta.schema_id = sc.schema_id
WHERE ta.is_ms_shipped = 0 AND pa.index_id IN (1,0)
GROUP BY sc.name,ta.name
ORDER BY SUM(pa.rows) DESC
See this:
Pipe output and capture exit status in Bash
Dumb solution: Connecting them through a named pipe (mkfifo). Then the command can be run second.
mkfifo pipe
tee out.txt < pipe &
command > pipe
echo $?
JComboBox Selection Change Listener?
Code example of ItemListener implementation
class ItemChangeListener implements ItemListener{
@Override
public void itemStateChanged(ItemEvent event) {
if (event.getStateChange() == ItemEvent.SELECTED) {
Object item = event.getItem();
// do something with object
}
}
}
Now we will get only selected item.
Then just add listener to your JComboBox
addItemListener(new ItemChangeListener());
NoClassDefFoundError on Maven dependency
By default, Maven doesn't bundle dependencies in the JAR file it builds, and you're not providing them on the classpath when you're trying to execute your JAR file at the command-line. This is why the Java VM can't find the library class files when trying to execute your code.
You could manually specify the libraries on the classpath with the -cp parameter, but that quickly becomes tiresome.
A better solution is to "shade" the library code into your output JAR file. There is a Maven plugin called the maven-shade-plugin to do this. You need to register it in your POM, and it will automatically build an "uber-JAR" containing your classes and the classes for your library code too when you run mvn package.
To simply bundle all required libraries, add the following to your POM:
<project>
...
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.4</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
...
</project>
Once this is done, you can rerun the commands you used above:
$ mvn package
$ java -cp target/bil138_4-0.0.1-SNAPSHOT.jar tr.edu.hacettepe.cs.b21127113.bil138_4.App
If you want to do further configuration of the shade plugin in terms of what JARs should be included, specifying a Main-Class for an executable JAR file, and so on, see the "Examples" section on the maven-shade-plugin site.
Auto refresh page every 30 seconds
Use setInterval instead of setTimeout. Though in this case either will be fine but setTimeout inherently triggers only once setInterval continues indefinitely.
<script language="javascript">
setInterval(function(){
window.location.reload(1);
}, 30000);
</script>
twig: IF with multiple conditions
If I recall correctly Twig doesn't support || and && operators, but requires or and and to be used respectively. I'd also use parentheses to denote the two statements more clearly although this isn't technically a requirement.
{%if ( fields | length > 0 ) or ( trans_fields | length > 0 ) %}
Expressions
Expressions can be used in {% blocks %} and ${ expressions }.
Operator Description
== Does the left expression equal the right expression?
+ Convert both arguments into a number and add them.
- Convert both arguments into a number and substract them.
* Convert both arguments into a number and multiply them.
/ Convert both arguments into a number and divide them.
% Convert both arguments into a number and calculate the rest of the integer division.
~ Convert both arguments into a string and concatenate them.
or True if the left or the right expression is true.
and True if the left and the right expression is true.
not Negate the expression.
For more complex operations, it may be best to wrap individual expressions in parentheses to avoid confusion:
{% if (foo and bar) or (fizz and (foo + bar == 3)) %}
HSL to RGB color conversion
Java implementation of Mohsen's code
Note that all integer are declared as float (i.e 1f) and must be float, else you will optain grey colors.
HSL to RGB
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes h, s, and l are contained in the set [0, 1] and
* returns r, g, and b in the set [0, 255].
*
* @param h The hue
* @param s The saturation
* @param l The lightness
* @return int array, the RGB representation
*/
public static int[] hslToRgb(float h, float s, float l){
float r, g, b;
if (s == 0f) {
r = g = b = l; // achromatic
} else {
float q = l < 0.5f ? l * (1 + s) : l + s - l * s;
float p = 2 * l - q;
r = hueToRgb(p, q, h + 1f/3f);
g = hueToRgb(p, q, h);
b = hueToRgb(p, q, h - 1f/3f);
}
int[] rgb = {to255(r), to255(g), to255(b)};
return rgb;
}
public static int to255(float v) { return (int)Math.min(255,256*v); }
/** Helper method that converts hue to rgb */
public static float hueToRgb(float p, float q, float t) {
if (t < 0f)
t += 1f;
if (t > 1f)
t -= 1f;
if (t < 1f/6f)
return p + (q - p) * 6f * t;
if (t < 1f/2f)
return q;
if (t < 2f/3f)
return p + (q - p) * (2f/3f - t) * 6f;
return p;
}
RGB to HSL
/**
* Converts an RGB color value to HSL. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes pR, pG, and bpBare contained in the set [0, 255] and
* returns h, s, and l in the set [0, 1].
*
* @param pR The red color value
* @param pG The green color value
* @param pB The blue color value
* @return float array, the HSL representation
*/
public static float[] rgbToHsl(int pR, int pG, int pB) {
float r = pR / 255f;
float g = pG / 255f;
float b = pB / 255f;
float max = (r > g && r > b) ? r : (g > b) ? g : b;
float min = (r < g && r < b) ? r : (g < b) ? g : b;
float h, s, l;
l = (max + min) / 2.0f;
if (max == min) {
h = s = 0.0f;
} else {
float d = max - min;
s = (l > 0.5f) ? d / (2.0f - max - min) : d / (max + min);
if (r > g && r > b)
h = (g - b) / d + (g < b ? 6.0f : 0.0f);
else if (g > b)
h = (b - r) / d + 2.0f;
else
h = (r - g) / d + 4.0f;
h /= 6.0f;
}
float[] hsl = {h, s, l};
return hsl;
}
How to get Time from DateTime format in SQL?
Try using this
Date to Time
select cast(getdate() as time(0))Time to TinyTime
select cast(orig_time as time(0))
var self = this?
Yeah, this appears to be a common standard. Some coders use self, others use me. It's used as a reference back to the "real" object as opposed to the event.
It's something that took me a little while to really get, it does look odd at first.
I usually do this right at the top of my object (excuse my demo code - it's more conceptual than anything else and isn't a lesson on excellent coding technique):
function MyObject(){
var me = this;
//Events
Click = onClick; //Allows user to override onClick event with their own
//Event Handlers
onClick = function(args){
me.MyProperty = args; //Reference me, referencing this refers to onClick
...
//Do other stuff
}
}
C++ vector of char array
You cannot store arrays in vectors (or in any other standard library container). The things that standard library containers store must be copyable and assignable, and arrays are neither of these.
If you really need to put an array in a vector (and you probably don't - using a vector of vectors or a vector of strings is more likely what you need), then you can wrap the array in a struct:
struct S {
char a[10];
};
and then create a vector of structs:
vector <S> v;
S s;
s.a[0] = 'x';
v.push_back( s );
Error in spring application context schema
I have recently had same issue with JPA-1.3
Nothing worked until I used explicit tools.xsd link
xsi:schemaLocation=" ...
http://www.springframework.org/schema/tool
http://www.springframework.org/schema/tool/spring-tool-3.2.xsd
... ">
like this:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/jdbc
http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/data/jpa
http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
http://www.springframework.org/schema/tool
http://www.springframework.org/schema/tool/spring-tool-3.2.xsd
">
How to get the new value of an HTML input after a keypress has modified it?
Here is a table of the different events and the levels of browser support. You need to pick an event which is supported across at least all modern browsers.
As you will see from the table, the keypress and change event do not have uniform support whereas the keyup event does.
Also make sure you attach the event handler using a cross-browser-compatible method...
Groovy String to Date
JChronic is your best choice. Here's an example that adds a .fromString() method to the Date class that parses just about anything you can throw at it:
Date.metaClass.'static'.fromString = { str ->
com.mdimension.jchronic.Chronic.parse(str).beginCalendar.time
}
You can call it like this:
println Date.fromString("Tue Aug 10 16:02:43 PST 2010")
println Date.fromString("july 1, 2012")
println Date.fromString("next tuesday")
How to style a checkbox using CSS
With pure CSS, nothing fancy with :before and :after, no transforms, you can turn off the default appearance and then style it with an inline background image like the following example. This works in Chrome, Firefox, Safari, and now Edge (Chromium Edge).
INPUT[type=checkbox]:focus
{
outline: 1px solid rgba(0, 0, 0, 0.2);
}
INPUT[type=checkbox]
{
background-color: #DDD;
border-radius: 2px;
appearance: none;
-webkit-appearance: none;
-moz-appearance: none;
width: 17px;
height: 17px;
cursor: pointer;
position: relative;
top: 5px;
}
INPUT[type=checkbox]:checked
{
background-color: #409fd6;
background: #409fd6 url("data:image/gif;base64,R0lGODlhCwAKAIABAP////3cnSH5BAEKAAEALAAAAAALAAoAAAIUjH+AC73WHIsw0UCjglraO20PNhYAOw==") 3px 3px no-repeat;
}<form>
<label><input type="checkbox"> I Agree To Terms & Conditions</label>
</form>Sort a list of lists with a custom compare function
Since the OP was asking for using a custom compare function (and this is what led me to this question as well), I want to give a solid answer here:
Generally, you want to use the built-in sorted() function which takes a custom comparator as its parameter. We need to pay attention to the fact that in Python 3 the parameter name and semantics have changed.
How the custom comparator works
When providing a custom comparator, it should generally return an integer/float value that follows the following pattern (as with most other programming languages and frameworks):
- return a negative value (
< 0) when the left item should be sorted before the right item - return a positive value (
> 0) when the left item should be sorted after the right item - return
0when both the left and the right item have the same weight and should be ordered "equally" without precedence
In the particular case of the OP's question, the following custom compare function can be used:
def compare(item1, item2):
return fitness(item1) - fitness(item2)
Using the minus operation is a nifty trick because it yields to positive values when the weight of left item1 is bigger than the weight of the right item2. Hence item1 will be sorted after item2.
If you want to reverse the sort order, simply reverse the subtraction: return fitness(item2) - fitness(item1)
Calling sorted() in Python 2
sorted(mylist, cmp=compare)
or:
sorted(mylist, cmp=lambda item1, item2: fitness(item1) - fitness(item2))
Calling sorted() in Python 3
from functools import cmp_to_key
sorted(mylist, key=cmp_to_key(compare))
or:
from functools import cmp_to_key
sorted(mylist, key=cmp_to_key(lambda item1, item2: fitness(item1) - fitness(item2)))
WordPress Get the Page ID outside the loop
If you're on a page and this does not work:
$page_object = get_queried_object();
$page_id = get_queried_object_id();
you can try to build the permalink manually with PHP so you can lookup the post ID:
// get or make permalink
$url = !empty(get_the_permalink()) ? get_the_permalink() : (isset($_SERVER['HTTPS']) ? "https" : "http") . "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
$permalink = strtok($url, '?');
// get post_id using url/permalink
$post_id = url_to_postid($url);
// want the post or postmeta? use get_post() or get_post_meta()
$post = get_post($post_id);
$postmeta = get_post_meta($post_id);
It may not catch every possible permalink (especially since I'm stripping out the query string), but you can modify it to fit your use case.
iOS: Modal ViewController with transparent background
I struggled a bit with the Interface Builder of XCode 7 to set the Presentation Style as @VenuGopalTewari suggested. In this version, there seems to be no Over Current Context or Over Full Screen presentation mode for the segue. Thus, to make it work, I set the mode to Default:
with
Additionally I set the presentation mode of the modally presented view controller to Over Full Screen:
How to force garbage collector to run?
GC.Collect()
from MDSN,
Use this method to try to reclaim all memory that is inaccessible.
All objects, regardless of how long they have been in memory, are considered for collection; however, objects that are referenced in managed code are not collected. Use this method to force the system to try to reclaim the maximum amount of available memory.
How to calculate rolling / moving average using NumPy / SciPy?
Starting in Numpy 1.20, the sliding_window_view provides a way to slide/roll through windows of elements. Windows that you can then individually average.
For instance, for a 4-element window:
from numpy.lib.stride_tricks import sliding_window_view
# values = np.array([5, 3, 8, 10, 2, 1, 5, 1, 0, 2])
np.average(sliding_window_view(values, window_shape = 4), axis=1)
# array([6.5, 5.75, 5.25, 4.5, 2.25, 1.75, 2])
Note the intermediary result of sliding_window_view:
# values = np.array([5, 3, 8, 10, 2, 1, 5, 1, 0, 2])
sliding_window_view(values, window_shape = 4)
# array([[ 5, 3, 8, 10],
# [ 3, 8, 10, 2],
# [ 8, 10, 2, 1],
# [10, 2, 1, 5],
# [ 2, 1, 5, 1],
# [ 1, 5, 1, 0],
# [ 5, 1, 0, 2]])
What do we mean by Byte array?
I assume you know what a byte is. A byte array is simply an area of memory containing a group of contiguous (side by side) bytes, such that it makes sense to talk about them in order: the first byte, the second byte etc..
Just as bytes can encode different types and ranges of data (numbers from 0 to 255, numbers from -128 to 127, single characters using ASCII e.g. 'a' or '%', CPU op-codes), each byte in a byte array may be any of these things, or contribute to some multi-byte values such as numbers with larger range (e.g. 16-bit unsigned int from 0..65535), international character sets, textual strings ("hello"), or part/all of a compiled computer programs.
The crucial thing about a byte array is that it gives indexed (fast), precise, raw access to each 8-bit value being stored in that part of memory, and you can operate on those bytes to control every single bit. The bad thing is the computer just treats every entry as an independent 8-bit number - which may be what your program is dealing with, or you may prefer some powerful data-type such as a string that keeps track of its own length and grows as necessary, or a floating point number that lets you store say 3.14 without thinking about the bit-wise representation. As a data type, it is inefficient to insert or remove data near the start of a long array, as all the subsequent elements need to be shuffled to make or fill the gap created/required.
How do I 'foreach' through a two-dimensional array?
string[][] languages = new string[2][];
languages[0] = new string[2];
languages[1] = new string[3];
// inserting data into double dimensional arrays.
for (int i = 0; i < 2; i++)
{
languages[0][i] = "Jagged"+i.ToString();
}
for (int j = 0; j < 3; j++)
{
languages[1][j] = "Jag"+j.ToString();
}
// doing foreach through 2 dimensional arrays.
foreach (string[] s in languages)
{
foreach (string a in s)
{
Console.WriteLine(a);
}
}
Javascript require() function giving ReferenceError: require is not defined
RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino and Node. Using a modular script loader like RequireJS will improve the speed and quality of your code.
IE 6+ .......... compatible ? Firefox 2+ ..... compatible ? Safari 3.2+ .... compatible ? Chrome 3+ ...... compatible ? Opera 10+ ...... compatible ?
http://requirejs.org/docs/download.html
Add this to your project: https://requirejs.org/docs/release/2.3.5/minified/require.js
and take a look at this http://requirejs.org/docs/api.html
Remove Duplicate objects from JSON Array
I know there are many answers already but the best one that worked for me for a complex json structure is:
var arr = [{ "State": "RWCW", "desc": "WEST", "code": "RWCW", "level": 0, "save": "RWCW : WEST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RCSW", "desc": "SOUTHWEST", "code": "RCSW", "level": 0, "save": "RCSW : SOUTHWEST", "attribute1": "", "attribute2": "" }, { "State": "RECW", "desc": "NORTHEAST", "code": "RECW", "level": 0, "save": "RECW : NORTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RWCW", "desc": "WEST", "code": "RWCW", "level": 0, "save": "RWCW : WEST", "attribute1": "", "attribute2": "" }, { "State": "RWCW", "desc": "WEST", "code": "RWCW", "level": 0, "save": "RWCW : WEST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RCSW", "desc": "SOUTHWEST", "code": "RCSW", "level": 0, "save": "RCSW : SOUTHWEST", "attribute1": "", "attribute2": "" }, { "State": "RECW", "desc": "NORTHEAST", "code": "RECW", "level": 0, "save": "RECW : NORTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RWCW", "desc": "WEST", "code": "RWCW", "level": 0, "save": "RWCW : WEST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RECW", "desc": "NORTHEAST", "code": "RECW", "level": 0, "save": "RECW : NORTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RWCW", "desc": "WEST", "code": "RWCW", "level": 0, "save": "RWCW : WEST", "attribute1": "", "attribute2": "" }, { "State": "RCSW", "desc": "SOUTHWEST", "code": "RCSW", "level": 0, "save": "RCSW : SOUTHWEST", "attribute1": "", "attribute2": "" }, { "State": "RWCW", "desc": "WEST", "code": "RWCW", "level": 0, "save": "RWCW : WEST", "attribute1": "", "attribute2": "" }, { "State": "RCNW", "desc": "MIDWEST", "code": "RCNW", "level": 0, "save": "RCNW : MIDWEST", "attribute1": "", "attribute2": "" }, { "State": "RCSW", "desc": "SOUTHWEST", "code": "RCSW", "level": 0, "save": "RCSW : SOUTHWEST", "attribute1": "", "attribute2": "" }, { "State": "RECW", "desc": "NORTHEAST", "code": "RECW", "level": 0, "save": "RECW : NORTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RCNW", "desc": "MIDWEST", "code": "RCNW", "level": 0, "save": "RCNW : MIDWEST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RECW", "desc": "NORTHEAST", "code": "RECW", "level": 0, "save": "RECW : NORTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RCNW", "desc": "MIDWEST", "code": "RCNW", "level": 0, "save": "RCNW : MIDWEST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RCNW", "desc": "MIDWEST", "code": "RCNW", "level": 0, "save": "RCNW : MIDWEST", "attribute1": "", "attribute2": "" }, { "State": "RSCW", "desc": "SOUTHEAST", "code": "RSCW", "level": 0, "save": "RSCW : SOUTHEAST", "attribute1": "", "attribute2": "" }, { "State": "RECW", "desc": "NORTHEAST", "code": "RECW", "level": 0, "save": "RECW : NORTHEAST", "attribute1": "", "attribute2": "" }];_x000D_
_x000D_
var clean = arr.filter((arr, index, self) =>_x000D_
index === self.findIndex((t) => (t.save === arr.save && t.State === arr.State)))_x000D_
_x000D_
console.log(clean);You can try this directly to chrome browser console and edit according to your need.
I hope this helps someone.
PHP Echo text Color
If it echoing out to a browser, you should use CSS. This would require also having the comment wrapped in an HTML tag. Something like:
echo '<p style="color: red; text-align: center">
Request has been sent. Please wait for my reply!
</p>';
T-SQL split string
I had to write something like this recently. Here's the solution I came up with. It's generalized for any delimiter string and I think it would perform slightly better:
CREATE FUNCTION [dbo].[SplitString]
( @string nvarchar(4000)
, @delim nvarchar(100) )
RETURNS
@result TABLE
( [Value] nvarchar(4000) NOT NULL
, [Index] int NOT NULL )
AS
BEGIN
DECLARE @str nvarchar(4000)
, @pos int
, @prv int = 1
SELECT @pos = CHARINDEX(@delim, @string)
WHILE @pos > 0
BEGIN
SELECT @str = SUBSTRING(@string, @prv, @pos - @prv)
INSERT INTO @result SELECT @str, @prv
SELECT @prv = @pos + LEN(@delim)
, @pos = CHARINDEX(@delim, @string, @pos + 1)
END
INSERT INTO @result SELECT SUBSTRING(@string, @prv, 4000), @prv
RETURN
END
jquery - is not a function error
When converting an ASP.Net webform prototype to a MVC site I got these errors:
TypeError: $(...).accordion is not a function
$("#accordion").accordion(
$('#dialog').dialog({
TypeError: $(...).dialog is not a function
It worked fine in the webforms. The problem/solution was this line in the _Layout.cshtml
@Scripts.Render("~/bundles/jquery")
Comment it out to see if the errors go away. Then fix it in the BundlesConfig:
bundles.Add(new ScriptBundle("~/bundles/jquery").Include(
"~/Scripts/jquery-{version}.js"));
Using OR in SQLAlchemy
or_() function can be useful in case of unknown number of OR query components.
For example, let's assume that we are creating a REST service with few optional filters, that should return record if any of filters return true. On the other side, if parameter was not defined in a request, our query shouldn't change. Without or_() function we must do something like this:
query = Book.query
if filter.title and filter.author:
query = query.filter((Book.title.ilike(filter.title))|(Book.author.ilike(filter.author)))
else if filter.title:
query = query.filter(Book.title.ilike(filter.title))
else if filter.author:
query = query.filter(Book.author.ilike(filter.author))
With or_() function it can be rewritten to:
query = Book.query
not_null_filters = []
if filter.title:
not_null_filters.append(Book.title.ilike(filter.title))
if filter.author:
not_null_filters.append(Book.author.ilike(filter.author))
if len(not_null_filters) > 0:
query = query.filter(or_(*not_null_filters))
MYSQL import data from csv using LOAD DATA INFILE
By these days (ending 2019) I prefer to use a tool like http://www.convertcsv.com/csv-to-sql.htm I you got a lot of rows you can run partitioned blocks saving user mistakes when csv come from a final user spreadsheet.
How do I reset the scale/zoom of a web app on an orientation change on the iPhone?
If you have the width set in the viewport :
<meta name = "viewport" content = "width=device-width; initial-scale=1.0;
maximum-scale=1.0;" />
And then change the orientation it will randomly zoom in sometimes (especially if you are dragging on the screen) to fix this don't set a width here I used :
<meta id="viewport" name="viewport" content="initial-scale=1.0; user-scalable=0;
minimum-scale=1.0; maximum-scale=1.0" />
This fixes the zoom whatever happens then you can use either window.onorientationchange event or if you want it to be platform independant (handy for testing) the window.innerWidth method.
PHP - Insert date into mysql
$date=$year."-".$month."-".$day;
$new_date=date('Y-m-d', strtotime($dob));
$status=0;
$insert_date = date("Y-m-d H:i:s");
$latest_insert_id=0;
$insertSql="insert into participationDetail (formId,name,city,emailId,dob,mobile,status,social_media1,social_media2,visa_status,tnc_status,data,gender,insertDate)values('".$formid."','".$name."','".$city."','".$email."','".$new_date."','".$mobile."','".$status."','".$link1."','".$link2."','".$visa_check."','".$tnc_check."','".json_encode($detail_arr,JSON_HEX_APOS)."','".$gender."','".$insert_date."')";
How to initialize an array in angular2 and typescript
You can use this construct:
export class AppComponent {
title:string;
myHero:string;
heroes: any[];
constructor() {
this.title = 'Tour of Heros';
this.heroes=['Windstorm','Bombasto','Magneta','Tornado']
this.myHero = this.heroes[0];
}
}
MYSQL: How to copy an entire row from one table to another in mysql with the second table having one extra column?
INSERT INTO dues_storage
SELECT field1, field2, ..., fieldN, CURRENT_DATE()
FROM dues
WHERE id = 5;
How to check String in response body with mockMvc
Spring MockMvc now has direct support for JSON. So you just say:
.andExpect(content().json("{'message':'ok'}"));
and unlike string comparison, it will say something like "missing field xyz" or "message Expected 'ok' got 'nok'.
This method was introduced in Spring 4.1.
Copy files to network computers on windows command line
check Robocopy:
ROBOCOPY \\server-source\c$\VMExports\ C:\VMExports\ /E /COPY:DAT
make sure you check what robocopy parameter you want. this is just an example.
type robocopy /? in a comandline/powershell on your windows system.
How to use border with Bootstrap
What others have mentioned about border vs border box is definitely correct. You can still get this to work without having to create any custom classes though: http://jsfiddle.net/panchroma/yfzdD/
HTML
<div class="container">
<div class="row" >
<div class="span12">
<div class="row">
<div class="span4"> 1 </div>
<div class="span4"> 2 </div>
<div class="span4"> 3 </div>
</div><!-- end nested row -->
</div><!-- end span 12 -->
</div> <!-- end row -->
</div><!-- end container -->
CSS
.span12{
border:solid 2px black;
background-color:grey;
}
Good luck!
Java: notify() vs. notifyAll() all over again
notify() lets you write more efficient code than notifyAll().
Consider the following piece of code that's executed from multiple parallel threads:
synchronized(this) {
while(busy) // a loop is necessary here
wait();
busy = true;
}
...
synchronized(this) {
busy = false;
notifyAll();
}
It can be made more efficient by using notify():
synchronized(this) {
if(busy) // replaced the loop with a condition which is evaluated only once
wait();
busy = true;
}
...
synchronized(this) {
busy = false;
notify();
}
In the case if you have a large number of threads, or if the wait loop condition is costly to evaluate, notify() will be significantly faster than notifyAll(). For example, if you have 1000 threads then 999 threads will be awakened and evaluated after the first notifyAll(), then 998, then 997, and so on. On the contrary, with the notify() solution, only one thread will be awakened.
Use notifyAll() when you need to choose which thread will do the work next:
synchronized(this) {
while(idx != last+1) // wait until it's my turn
wait();
}
...
synchronized(this) {
last = idx;
notifyAll();
}
Finally, it's important to understand that in case of notifyAll(), the code inside synchronized blocks that have been awakened will be executed sequentially, not all at once. Let's say there are three threads waiting in the above example, and the fourth thread calls notifyAll(). All three threads will be awakened but only one will start execution and check the condition of the while loop. If the condition is true, it will call wait() again, and only then the second thread will start executing and will check its while loop condition, and so on.
How to change the status bar background color and text color on iOS 7?
For bar color: You provide a custom background image for the bar.
For text color: Use the information in About Text Handling in iOS
Express.js req.body undefined
You can try adding this line of code at the top, (after your require statements):
app.use(bodyParser.urlencoded({extended: true}));
As for the reasons as to why it works, check out the docs: https://www.npmjs.com/package/body-parser#bodyparserurlencodedoptions
RuntimeError on windows trying python multiprocessing
hello here is my structure for multi process
from multiprocessing import Process
import time
start = time.perf_counter()
def do_something(time_for_sleep):
print(f'Sleeping {time_for_sleep} second...')
time.sleep(time_for_sleep)
print('Done Sleeping...')
p1 = Process(target=do_something, args=[1])
p2 = Process(target=do_something, args=[2])
if
__name__ == '__main__':
p1.start()
p2.start()
p1.join()
p2.join()
finish = time.perf_counter()
print(f'Finished in {round(finish-start,2 )} second(s)')
you don't have to put imports in the name == 'main', just running the program you wish to running inside
What is LDAP used for?
LDAP is just a protocol to access structured information. LDAP has standardized local and remote access to information whereas in case of database there is only standardized local access and remote access is proprietary.
LDAP server is optimized for search operation and database for transactions(Insert/Delete).
For more information refer following link:
Hexadecimal string to byte array in C
Apart from the excellent answers above I though I would write a C function that does not use any libraries and has some guards against bad strings.
uint8_t* datahex(char* string) {
if(string == NULL)
return NULL;
size_t slength = strlen(string);
if((slength % 2) != 0) // must be even
return NULL;
size_t dlength = slength / 2;
uint8_t* data = malloc(dlength);
memset(data, 0, dlength);
size_t index = 0;
while (index < slength) {
char c = string[index];
int value = 0;
if(c >= '0' && c <= '9')
value = (c - '0');
else if (c >= 'A' && c <= 'F')
value = (10 + (c - 'A'));
else if (c >= 'a' && c <= 'f')
value = (10 + (c - 'a'));
else {
free(data);
return NULL;
}
data[(index/2)] += value << (((index + 1) % 2) * 4);
index++;
}
return data;
}
Explanation:
a. index / 2 | Division between integers will round down the value, so 0/2 = 0, 1/2 = 0, 2/2 = 1, 3/2 = 1, 4/2 = 2, 5/2 = 2, etc. So, for every 2 string characters we add the value to 1 data byte.
b. (index + 1) % 2 | We want odd numbers to result to 1 and even to 0 since the first digit of a hex string is the most significant and needs to be multiplied by 16. so for index 0 => 0 + 1 % 2 = 1, index 1 => 1 + 1 % 2 = 0 etc.
c. << 4 | Shift by 4 is multiplying by 16. example: b00000001 << 4 = b00010000
Apple Cover-flow effect using jQuery or other library?
There is an Apple style Gallery Slider over at http://www.jqueryfordesigners.com/slider-gallery/ which uses jQuery and the UI.
String MinLength and MaxLength validation don't work (asp.net mvc)
Try using this attribute, for example for password min length:
[StringLength(100, ErrorMessage = "???????????? ????? ?????? 20 ????????", MinimumLength = User.PasswordMinLength)]
CSS: Center block, but align contents to the left
THIS works
<div style="display:inline-block;margin:10px auto;">
<ul style="list-style-type:none;">
<li style="text-align:left;"><span class="red">?</span> YouTube AutoComplete Keyword Scraper software <em>root keyword text box</em>.</li>
<li style="text-align:left;"><span class="red">?</span> YouTube.com website <em>video search text box</em>.</li>
<li style="text-align:left;"><span class="red">?</span> YouTube AutoComplete Keyword Scraper software <em>scraped keywords listbox</em>.</li>
<li style="text-align:left;"><span class="red">?</span> YouTube AutoComplete Keyword Scraper software <em>right click context menu</em>.</li>
</ul>
</div>
How do I add one month to current date in Java?
tl;dr
LocalDate::plusMonths
Example:
LocalDate.now( )
.plusMonths( 1 );
Better to specify time zone.
LocalDate.now( ZoneId.of( "America/Montreal" )
.plusMonths( 1 );
java.time
The java.time framework is built into Java 8 and later. These classes supplant the old troublesome date-time classes such as java.util.Date, .Calendar, & java.text.SimpleDateFormat. The Joda-Time team also advises migration to java.time.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations.
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport and further adapted to Android in ThreeTenABP.
Date-only
If you want the date-only, use the LocalDate class.
ZoneId z = ZoneId.of( "America/Montreal" );
LocalDate today = LocalDate.now( z );
today.toString(): 2017-01-23
Add a month.
LocalDate oneMonthLater = today.plusMonths( 1 );
oneMonthLater.toString(): 2017-02-23
Date-time
Perhaps you want a time-of-day along with the date.
First get the current moment in UTC with a resolution of nanoseconds.
Instant instant = Instant.now();
Adding a month means determining dates. And determining dates means applying a time zone. For any given moment, the date varies around the world with a new day dawning earlier to the east. So adjust that Instant into a time zone.
ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant , zoneId );
Now add your month. Let java.time handle Leap month, and the fact that months vary in length.
ZonedDateTime zdtMonthLater = zdt.plusMonths( 1 );
You might want to adjust the time-of-day to the first moment of the day when making this kind of calculation. That first moment is not always 00:00:00.0 so let java.time determine the time-of-day.
ZonedDateTime zdtMonthLaterStartOfDay = zdtMonthLater.toLocalDate().atStartOfDay( zoneId );
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
- Java SE 8, Java SE 9, and later
- Built-in.
- Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
- Java SE 6 and Java SE 7
- Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
- Android
- The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
- See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
Joda-Time
Update: The Joda-Time project is now in maintenance mode. Its team advises migration to the java.time classes. I am leaving this section intact for posterity.
The Joda-Time library offers a method to add months in a smart way.
DateTimeZone timeZone = DateTimeZone.forID( "Europe/Paris" );
DateTime now = DateTime.now( timeZone );
DateTime nextMonth = now.plusMonths( 1 );
You might want to focus on the day by adjust the time-of-day to the first moment of the day.
DateTime nextMonth = now.plusMonths( 1 ).withTimeAtStartOfDay();
Terminating a script in PowerShell
Write-Error is for non-terminating errors and throw is for terminating errors
The Write-Error cmdlet declares a non-terminating error. By default, errors are sent in the error stream to the host program to be displayed, along with output.
Non-terminating errors write an error to the error stream, but they do not stop command processing. If a non-terminating error is declared on one item in a collection of input items, the command continues to process the other items in the collection.
To declare a terminating error, use the Throw keyword. For more information, see about_Throw (http://go.microsoft.com/fwlink/?LinkID=145153).
Export to csv/excel from kibana
I totally missed the export button at the bottom of each visualization. As for read only access...Shield from Elasticsearch might be worth exploring.
A weighted version of random.choice
If you happen to have Python 3, and are afraid of installing numpy or writing your own loops, you could do:
import itertools, bisect, random
def weighted_choice(choices):
weights = list(zip(*choices))[1]
return choices[bisect.bisect(list(itertools.accumulate(weights)),
random.uniform(0, sum(weights)))][0]
Because you can build anything out of a bag of plumbing adaptors! Although... I must admit that Ned's answer, while slightly longer, is easier to understand.