Waiting for Target Device to Come Online
For Linux users using KVM and facing this problem try setting the Graphics option on the Android Virtual Device to Software
instead of Automatic
or Hardware
. As previously mentioned in this answer.
I can confirm that the method works for Arch Linux, Ubuntu 16.04, as well as windows with or without a proprietary graphics card using Android Studio version 2.3.1+
How to run .APK file on emulator
You need to install the APK on the emulator. You can do this with the adb
command line tool that is included in the Android SDK.
adb -e install -r yourapp.apk
Once you've done that you should be able to run the app.
The -e
and -r
flags might not be necessary. They just specify that you are using an emulator (if you also have a device connected) and that you want to replace the app if it already exists.
How do I change screen orientation in the Android emulator?
Android Emulator Shortcuts
Ctrl+F11 Switch layout orientation portrait/landscape backwards
Ctrl+F12 Switch layout orientation portrait/landscape forwards
1. Main Device Keys
Home Home Button
F2 Left Softkey / Menu / Settings button (or Page up)
Shift+f2 Right Softkey / Star button (or Page down)
Esc Back Button
F3 Call/ dial Button
F4 Hang up / end call button
F5 Search Button
2. Other Device Keys
Ctrl+F5 Volume up (or + on numeric keyboard with Num Lock off)
Ctrl+F6 Volume down (or + on numeric keyboard with Num Lock off)
F7 Power Button
Ctrl+F3 Camera Button
Ctrl+F11 Switch layout orientation portrait/landscape backwards
Ctrl+F12 Switch layout orientation portrait/landscape forwards
F8 Toggle cell network
F9 Toggle code profiling
Alt+Enter Toggle fullscreen mode
F6 Toggle trackball mode
Using Camera in the Android emulator
Some elaboration, in the hope of clarifying what has already been said:
As stated above, Webcams are supported natively in the current SDK, but only on recent android versions (4.0 and higher)
Webcam detection is automatic where present. In 4.0.3, the camera defaults to the front-facing camera so a lot of applications (especially pre-2.3 applications, which can only fetch the default camera, i.e. the back-facing one) will still show you the old checkerbox-with-moving-square stand-in instead.
I think some more info is available in the following post: Camera on Android Eclipse emulator:
Or at least, that's the most information I've been able to find--aside from the brief, uninformative statements in the release notes for the SDK tools.
What's the difference between emulation and simulation?
Based on software and system engineering experience, I'd summarise the difference as follows:
Simulation: for me, this is always in software - every aspect of the real system is only MODELLED by some code and/or mathematics. Simulation attempts to accurately reproduce the behaviour (or predict it) of the real system, but only approximates it.
Emulation: As opposed to simulation, it does not APPROXIMATE the behaviour of the real system, it COPIES the behaviour of the real system. An emulator may involve hardware. But it may also be entirely in software. E.g. you get these software EMULATORS for old game consoles like the Sega Genesis. That is an emulator because it COPIES the real genesis functionality so much so that you can run the original Genesis code in the emulator. A genesis simulator would not be able to run the original code, it would only APPROXIMATE its behaviour, producing similar results, depending on how good the models of the original system were.
An emulator of a system component can be included in a larger system, completely replacing the component it is emulating - a simulator could not because it is not an accurate enough representation of the original component behaviour.
Making the Android emulator run faster
I've been using the Intel(86) CPU/ABI. I created another emulator using the ARM(armeabi-v7a) and i found quite an improvement with the speed. I'm using platform 4.1.2 API level 16
How to get the sign, mantissa and exponent of a floating point number
- Don't make functions that do multiple things.
- Don't mask then shift; shift then mask.
- Don't mutate values unnecessarily because it's slow, cache-destroying and error-prone.
- Don't use magic numbers.
/* NaNs, infinities, denormals unhandled */
/* assumes sizeof(float) == 4 and uses ieee754 binary32 format */
/* assumes two's-complement machine */
/* C99 */
#include <stdint.h>
#define SIGN(f) (((f) <= -0.0) ? 1 : 0)
#define AS_U32(f) (*(const uint32_t*)&(f))
#define FLOAT_EXPONENT_WIDTH 8
#define FLOAT_MANTISSA_WIDTH 23
#define FLOAT_BIAS ((1<<(FLOAT_EXPONENT_WIDTH-1))-1) /* 2^(e-1)-1 */
#define MASK(width) ((1<<(width))-1) /* 2^w - 1 */
#define FLOAT_IMPLICIT_MANTISSA_BIT (1<<FLOAT_MANTISSA_WIDTH)
/* correct exponent with bias removed */
int float_exponent(float f) {
return (int)((AS_U32(f) >> FLOAT_MANTISSA_WIDTH) & MASK(FLOAT_EXPONENT_WIDTH)) - FLOAT_BIAS;
}
/* of non-zero, normal floats only */
int float_mantissa(float f) {
return (int)(AS_U32(f) & MASK(FLOAT_MANTISSA_BITS)) | FLOAT_IMPLICIT_MANTISSA_BIT;
}
/* Hacker's Delight book is your friend. */
Android YouTube app Play Video Intent
Intent videoClient = new Intent(Intent.ACTION_VIEW);
videoClient.setData(Uri.parse("http://m.youtube.com/watch?v="+videoId));
startActivityForResult(videoClient, 1234);
Where videoId
is the video id of the youtube video that has to be played. This code works fine on Motorola Milestone.
But basically what we can do is to check for what activity is loaded when you start the Youtube app and accordingly substitute for the packageName and the className.
Enabling WiFi on Android Emulator
As of now, with Revision 26.1.3 of the android emulator, it is finally possible on the image v8 of the API 25.
If the emulator was created before you upgrade to the latest API 25 image, you need to wipe data or simply delete and recreate your image if you prefer.
Added support for Wi-Fi in some system images (currently only API
level 25). An access point called "AndroidWifi" is available and
Android automatically connects to it. Wi-Fi support can be disabled by
running the emulator with the command line parameter -feature -Wifi.
from https://developer.android.com/studio/releases/emulator.html#26-1-3
Simulator or Emulator? What is the difference?
An emulator is a model of a system which will accept any valid input that that the emulated system would accept, and produce the same output or result. So your software is an emulator, only if it reproduces the behavior of the emulated system precisely.
Merging dictionaries in C#
A version from @user166390 answer with an added IEqualityComparer
parameter to allow for case insensitive key comparison.
public static T MergeLeft<T, K, V>(this T me, params Dictionary<K, V>[] others)
where T : Dictionary<K, V>, new()
{
return me.MergeLeft(me.Comparer, others);
}
public static T MergeLeft<T, K, V>(this T me, IEqualityComparer<K> comparer, params Dictionary<K, V>[] others)
where T : Dictionary<K, V>, new()
{
T newMap = Activator.CreateInstance(typeof(T), new object[] { comparer }) as T;
foreach (Dictionary<K, V> src in
(new List<Dictionary<K, V>> { me }).Concat(others))
{
// ^-- echk. Not quite there type-system.
foreach (KeyValuePair<K, V> p in src)
{
newMap[p.Key] = p.Value;
}
}
return newMap;
}
Connection refused on docker container
If you are using Docker toolkit on window 10 home you will need to access the webpage through docker-machine ip command. It is generally 192.168.99.100:
It is assumed that you are running with publish command like below.
docker run -it -p 8080:8080 demo
With Window 10 pro version you can access with localhost or corresponding loopback 127.0.0.1:8080 etc (Tomcat or whatever you wish). This is because you don't have a virtual box there and docker is running directly on Window Hyper V and loopback is directly accessible.
Verify the hosts file in window for any digression. It should have
127.0.0.1 mapped to localhost
Make child visible outside an overflow:hidden parent
This is an old question but encountered it myself.
I have semi-solutions that work situational for the former question("Children visible in overflow:hidden parent")
If the parent div does not need to be position:relative, simply set the children styles to visibility:visible.
If the parent div does need to be position:relative, the only way possible I found to show the children was position:fixed. This worked for me in my situation luckily enough but I would imagine it wouldn't work in others.
Here is a crappy example just post into a html file to view.
<div style="background: #ff00ff; overflow: hidden; width: 500px; height: 500px; position: relative;">
<div style="background: #ff0000;position: fixed; top: 10px; left: 10px;">asd
<div style="background: #00ffff; width: 200px; overflow: visible; position: absolute; visibility: visible; clear:both; height: 1000px; top: 100px; left: 10px;"> a</div>
</div>
</div>
How do you add input from user into list in Python
code below allows user to input items until they press enter key to stop:
In [1]: items=[]
...: i=0
...: while 1:
...: i+=1
...: item=input('Enter item %d: '%i)
...: if item=='':
...: break
...: items.append(item)
...: print(items)
...:
Enter item 1: apple
Enter item 2: pear
Enter item 3: #press enter here
['apple', 'pear']
In [2]:
Android Imagebutton change Image OnClick
To switch between different images when the ImageButton is clicked I used a boolean like this:
ImageButton imageButton;
boolean buttonOn;
imageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!buttonOn) {
buttonOn = true;
imageButton.setBackground(getResources().getDrawable(R.drawable.button_is_on));
} else {
buttonOn = false;
imageButton.setBackground(getResources().getDrawable(R.drawable.button_is_off));
}
}
});
How to make a JSON call to a url?
DickFeynman's answer is a workable solution for any circumstance in which JQuery is not a good fit, or isn't otherwise necessary. As ComFreek notes, this requires setting the CORS headers on the server-side. If it's your service, and you have a handle on the bigger question of security, then that's entirely feasible.
Here's a listing of a Flask service, setting the CORS headers, grabbing data from a database, responding with JSON, and working happily with DickFeynman's approach on the client-side:
#!/usr/bin/env python
from __future__ import unicode_literals
from flask import Flask, Response, jsonify, redirect, request, url_for
from your_model import *
import os
try:
import simplejson as json;
except ImportError:
import json
try:
from flask.ext.cors import *
except:
from flask_cors import *
app = Flask(__name__)
@app.before_request
def before_request():
try:
# Provided by an object in your_model
app.session = SessionManager.connect()
except:
print "Database connection failed."
@app.teardown_request
def shutdown_session(exception=None):
app.session.close()
# A route with a CORS header, to enable your javascript client to access
# JSON created from a database query.
@app.route('/whatever-data/', methods=['GET', 'OPTIONS'])
@cross_origin(headers=['Content-Type'])
def json_data():
whatever_list = []
results_json = None
try:
# Use SQL Alchemy to select all Whatevers, WHERE size > 0.
whatevers = app.session.query(Whatever).filter(Whatever.size > 0).all()
if whatevers and len(whatevers) > 0:
for whatever in whatevers:
# Each whatever is able to return a serialized version of itself.
# Refer to your_model.
whatever_list.append(whatever.serialize())
# Convert a list to JSON.
results_json = json.dumps(whatever_list)
except SQLAlchemyError as e:
print 'Error {0}'.format(e)
exit(0)
if len(whatevers) < 1 or not results_json:
exit(0)
else:
# Because we used json.dumps(), rather than jsonify(),
# we need to create a Flask Response object, here.
return Response(response=str(results_json), mimetype='application/json')
if __name__ == '__main__':
#@NOTE Not suitable for production. As configured,
# your Flask service is in debug mode and publicly accessible.
app.run(debug=True, host='0.0.0.0', port=5001) # http://localhost:5001/
your_model contains the serialization method for your whatever, as well as the database connection manager (which could stand a little refactoring, but suffices to centralize the creation of database sessions, in bigger systems or Model/View/Control architectures). This happens to use postgreSQL, but could just as easily use any server side data store:
#!/usr/bin/env python
# Filename: your_model.py
import time
import psycopg2
import psycopg2.pool
import psycopg2.extras
from psycopg2.extensions import adapt, register_adapter, AsIs
from sqlalchemy import update
from sqlalchemy.orm import *
from sqlalchemy.exc import *
from sqlalchemy.dialects import postgresql
from sqlalchemy import Table, Column, Integer, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
class SessionManager(object):
@staticmethod
def connect():
engine = create_engine('postgresql://id:passwd@localhost/mydatabase',
echo = True)
Session = sessionmaker(bind = engine,
autoflush = True,
expire_on_commit = False,
autocommit = False)
session = Session()
return session
@staticmethod
def declareBase():
engine = create_engine('postgresql://id:passwd@localhost/mydatabase', echo=True)
whatever_metadata = MetaData(engine, schema ='public')
Base = declarative_base(metadata=whatever_metadata)
return Base
Base = SessionManager.declareBase()
class Whatever(Base):
"""Create, supply information about, and manage the state of one or more whatever.
"""
__tablename__ = 'whatever'
id = Column(Integer, primary_key=True)
whatever_digest = Column(VARCHAR, unique=True)
best_name = Column(VARCHAR, nullable = True)
whatever_timestamp = Column(BigInteger, default = time.time())
whatever_raw = Column(Numeric(precision = 1000, scale = 0), default = 0.0)
whatever_label = Column(postgresql.VARCHAR, nullable = True)
size = Column(BigInteger, default = 0)
def __init__(self,
whatever_digest = '',
best_name = '',
whatever_timestamp = 0,
whatever_raw = 0,
whatever_label = '',
size = 0):
self.whatever_digest = whatever_digest
self.best_name = best_name
self.whatever_timestamp = whatever_timestamp
self.whatever_raw = whatever_raw
self.whatever_label = whatever_label
# Serialize one way or another, just handle appropriately in the client.
def serialize(self):
return {
'best_name' :self.best_name,
'whatever_label':self.whatever_label,
'size' :self.size,
}
In retrospect, I might have serialized the whatever objects as lists, rather than a Python dict, which might have simplified their processing in the Flask service, and I might have separated concerns better in the Flask implementation (The database call probably shouldn't be built-in the the route handler), but you can improve on this, once you have a working solution in your own development environment.
Also, I'm not suggesting people avoid JQuery. But, if JQuery's not in the picture, for one reason or another, this approach seems like a reasonable alternative.
It works, in any case.
Here's my implementation of DickFeynman's approach, in the the client:
<script type="text/javascript">
var addr = "dev.yourserver.yourorg.tld"
var port = "5001"
function Get(whateverUrl){
var Httpreq = new XMLHttpRequest(); // a new request
Httpreq.open("GET",whateverUrl,false);
Httpreq.send(null);
return Httpreq.responseText;
}
var whatever_list_obj = JSON.parse(Get("http://" + addr + ":" + port + "/whatever-data/"));
whatever_qty = whatever_list_obj.length;
for (var i = 0; i < whatever_qty; i++) {
console.log(whatever_list_obj[i].best_name);
}
</script>
I'm not going to list my console output, but I'm looking at a long list of whatever.best_name strings.
More to the point: The whatever_list_obj is available for use in my javascript namespace, for whatever I care to do with it, ...which might include generating graphics with D3.js, mapping with OpenLayers or CesiumJS, or calculating some intermediate values which have no particular need to live in my DOM.
Is it possible to read from a InputStream with a timeout?
If your InputStream is backed by a Socket, you can set a Socket timeout (in milliseconds) using setSoTimeout. If the read() call doesn't unblock within the timeout specified, it will throw a SocketTimeoutException.
Just make sure that you call setSoTimeout on the Socket before making the read() call.
Simple Vim commands you wish you'd known earlier
In our software shop, variable declarations need to be sorted. In the language that we use, multiple variables can appear on the same line.
new var1,var2,var3,etc
It is a real pain to go through and visually attempt to sort each and every variable. The block highlighting, and sort command in Vim are my friends here:
- Move the cursor to the first variable to be sorted.
- Issue the v command to enter visual mode.
- Move the cursor to the end of the last variable to be sorted in my case I enter $ to go to the end of the line).
- Execute the !sort command to tell Vim to sort the highlighted text.
This will only work if their exists a 'sort' command on the underlying system.
How to overload __init__ method based on argument type?
You should use isinstance
isinstance(...)
isinstance(object, class-or-type-or-tuple) -> bool
Return whether an object is an instance of a class or of a subclass thereof.
With a type as second argument, return whether that is the object's type.
The form using a tuple, isinstance(x, (A, B, ...)), is a shortcut for
isinstance(x, A) or isinstance(x, B) or ... (etc.).
JOptionPane Input to int
// sample code for addition using JOptionPane
import javax.swing.JOptionPane;
public class Addition {
public static void main(String[] args) {
String firstNumber = JOptionPane.showInputDialog("Input <First Integer>");
String secondNumber = JOptionPane.showInputDialog("Input <Second Integer>");
int num1 = Integer.parseInt(firstNumber);
int num2 = Integer.parseInt(secondNumber);
int sum = num1 + num2;
JOptionPane.showMessageDialog(null, "Sum is" + sum, "Sum of two Integers", JOptionPane.PLAIN_MESSAGE);
}
}
Sorting a set of values
From a comment:
I want to sort each set.
That's easy. For any set s
(or anything else iterable), sorted(s)
returns a list of the elements of s
in sorted order:
>>> s = set(['0.000000000', '0.009518000', '10.277200999', '0.030810999', '0.018384000', '4.918560000'])
>>> sorted(s)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '10.277200999', '4.918560000']
Note that sorted
is giving you a list
, not a set
. That's because the whole point of a set, both in mathematics and in almost every programming language,* is that it's not ordered: the sets {1, 2}
and {2, 1}
are the same set.
You probably don't really want to sort those elements as strings, but as numbers (so 4.918560000 will come before 10.277200999 rather than after).
The best solution is most likely to store the numbers as numbers rather than strings in the first place. But if not, you just need to use a key
function:
>>> sorted(s, key=float)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '4.918560000', '10.277200999']
For more information, see the Sorting HOWTO in the official docs.
* See the comments for exceptions.
convert json ipython notebook(.ipynb) to .py file
From the notebook menu you can save the file directly as a python script. Go to the 'File' option of the menu, then select 'Download as' and there you would see a 'Python (.py)' option.
Another option would be to use nbconvert from the command line:
jupyter nbconvert --to script 'my-notebook.ipynb'
Have a look here.
Found shared references to a collection org.hibernate.HibernateException
Explanation on practice. If you try to save your object, e.g.:
Set<Folder> folders = message.getFolders();
folders.remove(inputFolder);
folders.add(trashFolder);
message.setFiles(folders);
MESSAGESDAO.getMessageDAO().save(message);
you don't need to set updated object to a parent object:
message.setFiles(folders);
Simple save your parent object like:
Set<Folder> folders = message.getFolders();
folders.remove(inputFolder);
folders.add(trashFolder);
// Not set updated object here
MESSAGESDAO.getMessageDAO().save(message);
How to make a div fill a remaining horizontal space?
The problem that I found with Boushley's answer is that if the right column is longer than the left it will just wrap around the left and resume filling the whole space. This is not the behavior I was looking for. After searching through lots of 'solutions' I found a tutorial (now link is dead) on creating three column pages.
The author offer's three different ways, one fixed width, one with three variable columns and one with fixed outer columns and a variable width middle. Much more elegant and effective than other examples I found. Significantly improved my understanding of CSS layout.
Basically, in the simple case above, float the first column left and give it a fixed width. Then give the column on the right a left-margin that is a little wider than the first column. That's it. Done. Ala Boushley's code:
Here's a demo in Stack Snippets & jsFiddle
_x000D_
_x000D_
#left {_x000D_
float: left;_x000D_
width: 180px;_x000D_
}_x000D_
_x000D_
#right {_x000D_
margin-left: 180px;_x000D_
}_x000D_
_x000D_
/* just to highlight divs for example*/_x000D_
#left { background-color: pink; }_x000D_
#right { background-color: lightgreen;}
_x000D_
<div id="left"> left </div>_x000D_
<div id="right"> right </div>
_x000D_
_x000D_
_x000D_
With Boushley's example the left column holds the other column to the right. As soon as the left column ends the right begins filling the whole space again. Here the right column simply aligns further into the page and the left column occupies it's big fat margin. No flow interactions needed.
Convert factor to integer
Quoting directly from the help page for factor
:
To transform a factor f to its original numeric values, as.numeric(levels(f))[f]
is recommended and slightly more efficient than as.numeric(as.character(f))
.
C++ error 'Undefined reference to Class::Function()'
This part has problems:
Card* cardArray;
void Deck() {
cardArray = new Card[NUM_TOTAL_CARDS];
int cardCount = 0;
for (int i = 0; i > NUM_SUITS; i++) { //Error
for (int j = 0; j > NUM_RANKS; j++) { //Error
cardArray[cardCount] = Card(Card::Rank(i), Card::Suit(j) );
cardCount++;
}
}
}
cardArray
is a dynamic array, but not a member of Card
class. It is strange if you would like to initialize a dynamic array which is not member of the class
void Deck()
is not constructor of class Deck since you missed the
scope resolution operator. You may be confused with defining the constructor and the function with name Deck
and return type void
.
- in your loops, you should use
<
not >
otherwise, loop will never
be executed.
Can't start hostednetwork
Let alone enabling the network adapter under Device Manager may not help. The following helped me resolved the issue.
I tried Disabling and Enabling the Wifi Adapter (i.e. the actual Wifi device adapter not the virtual adapters) in Control Panel -> Network and Internet -> Network Connections altogether worked for me. The same can be done from the Device Manager too. This surely resets the adapter settings and for the Wifi Adapter and the Virtual Miniport adapters.
However, please make sure that the mode is set to allow
as in the below example before you run the start command.
netsh wlan set hostednetwork mode=allow ssid=ssidOfUrChoice key=keyOfUrChoice
and after that run the command netsh wlan start hostednetwork
.
Also once the usage is over with the Miniport adapter connection, it is a good practice to stop it using the following command.
netsh wlan stop hostednetwork
Hope it helps.
Oracle database: How to read a BLOB?
You can dump the value in hex using UTL_RAW.CAST_TO_RAW(UTL_RAW.CAST_TO_VARCHAR2())
.
SELECT b FROM foo;
-- (BLOB)
SELECT UTL_RAW.CAST_TO_RAW(UTL_RAW.CAST_TO_VARCHAR2(b))
FROM foo;
-- 1F8B080087CDC1520003F348CDC9C9D75128CF2FCA49D1E30200D7BBCDFC0E000000
This is handy because you this is the same format used for inserting into BLOB columns:
CREATE GLOBAL TEMPORARY TABLE foo (
b BLOB);
INSERT INTO foo VALUES ('1f8b080087cdc1520003f348cdc9c9d75128cf2fca49d1e30200d7bbcdfc0e000000');
DESC foo;
-- Name Null Type
-- ---- ---- ----
-- B BLOB
However, at a certain point (2000 bytes?) the corresponding hex string exceeds Oracle’s maximum string length. If you need to handle that case, you’ll have to combine How do I get textual contents from BLOB in Oracle SQL with the documentation for DMBS_LOB.SUBSTR
for a more complicated approach that will allow you to see substrings of the BLOB.
jQuery prevent change for select
if anybody still interested, this solved the problem, using jQuery 3.3.1
jQuery('.class').each(function(i,v){
jQuery(v).data('lastSelected', jQuery(v).find('option:selected').val());
jQuery(v).on('change', function(){
if(!confirm('Are you sure?'))
{
var self = jQuery(this);
jQuery(this).find('option').each(function(key, value){
if(parseInt(jQuery(value).val()) === parseInt(self.data('lastSelected')))
{
jQuery(this).prop('selected', 'selected');
}
});
}
jQuery(v).data('lastSelected', jQuery(v).find('option:selected').val());
});
});
Rename multiple files based on pattern in Unix
You can also use below script. it is very easy to run on terminal...
//Rename multiple files at a time
for file in FILE_NAME*
do
mv -i "${file}" "${file/FILE_NAME/RENAMED_FILE_NAME}"
done
Example:-
for file in hello*
do
mv -i "${file}" "${file/hello/JAISHREE}"
done
How can I list the contents of a directory in Python?
Below code will list directories and the files within the dir. The other one is os.walk
def print_directory_contents(sPath):
import os
for sChild in os.listdir(sPath):
sChildPath = os.path.join(sPath,sChild)
if os.path.isdir(sChildPath):
print_directory_contents(sChildPath)
else:
print(sChildPath)
Center align a column in twitter bootstrap
If you cannot put 1 column, you can simply put 2 column in the middle...
(I am just combining answers)
For Bootstrap 3
<div class="row">
<div class="col-lg-5 ">5 columns left</div>
<div class="col-lg-2 col-centered">2 column middle</div>
<div class="col-lg-5">5 columns right</div>
</div>
Even, you can text centered column by adding this to style:
.col-centered{
display: block;
margin-left: auto;
margin-right: auto;
text-align: center;
}
Additionally, there is another solution here
Execute script after specific delay using JavaScript
If you only need to test a delay you can use this:
function delay(ms) {
ms += new Date().getTime();
while (new Date() < ms){}
}
And then if you want to delay for 2 second you do:
delay(2000);
Might not be the best for production though. More on that in the comments
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):
_x000D_
_x000D_
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_
);
_x000D_
_x000D_
_x000D_
How can I get javascript to read from a .json file?
You can do it like...
Just give the proper path of your json file...
<!doctype html>
<html>
<head>
<script type="text/javascript" src="abc.json"></script>
<script type="text/javascript" >
function load() {
var mydata = JSON.parse(data);
alert(mydata.length);
var div = document.getElementById('data');
for(var i = 0;i < mydata.length; i++)
{
div.innerHTML = div.innerHTML + "<p class='inner' id="+i+">"+ mydata[i].name +"</p>" + "<br>";
}
}
</script>
</head>
<body onload="load()">
<div id= "data">
</div>
</body>
</html>
Simply getting the data and appending it to a div... Initially printing the length in alert.
Here is my Json file: abc.json
data = '[{"name" : "Riyaz"},{"name" : "Javed"},{"name" : "Arun"},{"name" : "Sunil"},{"name" : "Rahul"},{"name" : "Anita"}]';
How do I sum values in a column that match a given condition using pandas?
You can also do this without using groupby or loc. By simply including the condition in code. Let the name of dataframe be df. Then you can try :
df[df['a']==1]['b'].sum()
or you can also try :
sum(df[df['a']==1]['b'])
Another way could be to use the numpy library of python :
import numpy as np
print(np.where(df['a']==1, df['b'],0).sum())
Can someone explain __all__ in Python?
Linked to, but not explicitly mentioned here, is exactly when __all__
is used. It is a list of strings defining what symbols in a module will be exported when from <module> import *
is used on the module.
For example, the following code in a foo.py
explicitly exports the symbols bar
and baz
:
__all__ = ['bar', 'baz']
waz = 5
bar = 10
def baz(): return 'baz'
These symbols can then be imported like so:
from foo import *
print(bar)
print(baz)
# The following will trigger an exception, as "waz" is not exported by the module
print(waz)
If the __all__
above is commented out, this code will then execute to completion, as the default behaviour of import *
is to import all symbols that do not begin with an underscore, from the given namespace.
Reference: https://docs.python.org/tutorial/modules.html#importing-from-a-package
NOTE: __all__
affects the from <module> import *
behavior only. Members that are not mentioned in __all__
are still accessible from outside the module and can be imported with from <module> import <member>
.
Optimal number of threads per core
4000 threads at one time is pretty high.
The answer is yes and no. If you are doing a lot of blocking I/O in each thread, then yes, you could show significant speedups doing up to probably 3 or 4 threads per logical core.
If you are not doing a lot of blocking things however, then the extra overhead with threading will just make it slower. So use a profiler and see where the bottlenecks are in each possibly parallel piece. If you are doing heavy computations, then more than 1 thread per CPU won't help. If you are doing a lot of memory transfer, it won't help either. If you are doing a lot of I/O though such as for disk access or internet access, then yes multiple threads will help up to a certain extent, or at the least make the application more responsive.
Laravel Soft Delete posts
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;
class Post extends Model {
use SoftDeletes;
protected $table = 'posts';
// ...
}
When soft deleting a model, it is not actually removed from your
database. Instead, a deleted_at
timestamp is set on the record. To
enable soft deletes for a model, specify the softDelete
property on
the model (Documentation).
use Illuminate\Database\Eloquent\SoftDeletingTrait; // <-- This is required
class Post extends Eloquent {
use SoftDeletingTrait;
protected $table = 'posts';
// ...
}
Prior to Version 4.2 (But not 4.2 & Later)
For example (Using a posts
table and Post
model):
class Post extends Eloquent {
protected $table = 'posts';
protected $softDelete = true;
// ...
}
To add a deleted_at column to your table, you may use the softDeletes
method from a migration:
For example (Migration class' up
method for posts
table) :
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
Schema::create('posts', function(Blueprint $table)
{
$table->increments('id');
// more fields
$table->softDeletes(); // <-- This will add a deleted_at field
$table->timeStamps();
});
}
Now, when you call the delete
method on the model, the deleted_at
column will be set to the current timestamp
. When querying a model that uses soft deletes, the "deleted" models will not be included in query results. To soft delete
a model you may use:
$model = Contents::find( $id );
$model->delete();
Deleted (soft) models are identified by the timestamp
and if deleted_at
field is NULL
then it's not deleted and using the restore
method actually makes the deleted_at
field NULL
. To permanently delete a model you may use forceDelete
method.
How to check db2 version
SELECT GETVARIABLE(('SYSIBM.VERSION')
FROM SYSIBM.SYSDUMMY1;
-- PPP IS PRODUCT STRING 'DSN'
-- VV IS VERSION NUMBER E.G., 10, 11
-- M IS MAINTENANCE LEVEL E.G. 5
-DISPLAY GROUP
THIS WILL DISPLAY THE LEVEL CM, ENFM, N
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.
Exception: "URI formats are not supported"
Try This
ImagePath = "http://localhost/profilepics/abc.png";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(ImagePath);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream receiveStream = response.GetResponseStream();
Angular.js programmatically setting a form field to dirty
I'm not sure exactly why you're trying to mark the fields dirty, but I found myself in a similar situation because I wanted validation errors to show up when somebody attempted to submit an invalid form. I ended up using jQuery to remove the .ng-pristine
class tags and add .ng-dirty
class tags to the appropriate fields. For example:
$scope.submit = function() {
// `formName` is the value of the `name` attribute on your `form` tag
if (this.formName.$invalid)
{
$('.ng-invalid:not("form")').each(function() {
$(this).removeClass('ng-pristine').addClass('ng-dirty');
});
// the form element itself is index zero, so the first input is typically at index 1
$('.ng-invalid')[1].focus();
}
}
C# : changing listbox row color?
I find the solution for listbox items' background to yellow. I tried the following solution to achieve the output.
for (int i = 0; i < lstEquipmentItem.Items.Count; i++)
{
if ((bool)ds.Tables[0].Rows[i]["Valid_Equipment"] == false)
{
lblTKMWarning.Text = "Invalid Equipment & Serial Numbers are highlited.";
lblTKMWarning.ForeColor = System.Drawing.Color.Red;
lstEquipmentItem.Items[i].Attributes.Add("style", "background-color:Yellow");
Count++;
}
}
Activity restart on rotation Android
Add this line to your manifest :-
android:configChanges="orientation|keyboard|keyboardHidden|screenSize|screenLayout|uiMode"
and this snippet to the activity :-
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
}
How do I apply a perspective transform to a UIView?
You can only use Core Graphics (Quartz, 2D only) transforms directly applied to a UIView's transform property. To get the effects in coverflow, you'll have to use CATransform3D, which are applied in 3-D space, and so can give you the perspective view you want. You can only apply CATransform3Ds to layers, not views, so you're going to have to switch to layers for this.
Check out the "CovertFlow" sample that comes with Xcode. It's mac-only (ie not for iPhone), but a lot of the concepts transfer well.
Perform curl request in javascript?
curl is a command in linux (and a library in php). Curl typically makes an HTTP request.
What you really want to do is make an HTTP (or XHR) request from javascript.
Using this vocab you'll find a bunch of examples, for starters:
Sending authorization headers with jquery and ajax
Essentially you will want to call $.ajax
with a few options for the header, etc.
$.ajax({
url: 'https://api.wit.ai/message?v=20140826&q=',
beforeSend: function(xhr) {
xhr.setRequestHeader("Authorization", "Bearer 6QXNMEMFHNY4FJ5ELNFMP5KRW52WFXN5")
}, success: function(data){
alert(data);
//process the JSON data etc
}
})
Placeholder Mixin SCSS/CSS
To avoid 'Unclosed block: CssSyntaxError' errors being thrown from sass compilers add a ';' to the end of @content.
@mixin placeholder {
::-webkit-input-placeholder { @content;}
:-moz-placeholder { @content;}
::-moz-placeholder { @content;}
:-ms-input-placeholder { @content;}
}
HSL to RGB color conversion
For all who said that Garry Tan solution converting incorrect from RGB to HSL and back. It because he left out fraction part of number in his code.
I corrected his code (javascript).
Sorry for link on russian languadge, but on english absent - HSL-wiki
function toHsl(r, g, b)
{
r /= 255.0;
g /= 255.0;
b /= 255.0;
var max = Math.max(r, g, b);
var min = Math.min(r, g, b);
var h, s, l = (max + min) / 2.0;
if(max == min)
{
h = s = 0;
}
else
{
var d = max - min;
s = (l > 0.5 ? d / (2.0 - max - min) : d / (max + min));
if(max == r && g >= b)
{
h = 1.0472 * (g - b) / d ;
}
else if(max == r && g < b)
{
h = 1.0472 * (g - b) / d + 6.2832;
}
else if(max == g)
{
h = 1.0472 * (b - r) / d + 2.0944;
}
else if(max == b)
{
h = 1.0472 * (r - g) / d + 4.1888;
}
}
return {
str: 'hsl(' + parseInt(h / 6.2832 * 360.0 + 0.5) + ',' + parseInt(s * 100.0 + 0.5) + '%,' + parseInt(l * 100.0 + 0.5) + '%)',
obj: { h: parseInt(h / 6.2832 * 360.0 + 0.5), s: parseInt(s * 100.0 + 0.5), l: parseInt(l * 100.0 + 0.5) }
};
};
Center the content inside a column in Bootstrap 4
There are multiple horizontal centering methods in Bootstrap 4...
text-center
for center display:inline
elements
offset-*
or mx-auto
can be used to center column (col-*
)
- or,
justify-content-center
on the row
to center columns (col-*
)
mx-auto
for centering display:block
elements inside d-flex
mx-auto
(auto x-axis margins) will center display:block
or display:flex
elements that have a defined width, (%, vw, px, etc..). Flexbox is used by default on grid columns, so there are also various flexbox centering methods.
Demo of the Bootstrap 4 Centering Methods
In your case, use mx-auto
to center the col-3
and text-center
to center it's content..
<div class="row">
<div class="col-3 mx-auto">
<div class="text-center">
center
</div>
</div>
</div>
https://codeply.com/go/GRUfnxl3Ol
or, using justify-content-center
on flexbox elements (.row
):
<div class="container">
<div class="row justify-content-center">
<div class="col-3 text-center">
center
</div>
</div>
</div>
Also see:
Vertical Align Center in Bootstrap 4
Loading cross-domain endpoint with AJAX
jQuery Ajax Notes
- Due to browser security restrictions, most Ajax requests are subject to the same origin policy; the request can not successfully retrieve data from a different domain, subdomain, port, or protocol.
- Script and JSONP requests are not subject to the same origin policy restrictions.
There are some ways to overcome the cross-domain barrier:
There are some plugins that help with cross-domain requests:
Heads up!
The best way to overcome this problem, is by creating your own proxy in the back-end, so that your proxy will point to the services in other domains, because in the back-end not exists the same origin policy restriction. But if you can't do that in back-end, then pay attention to the following tips.
Warning!
Using third-party proxies is not a secure practice, because they can keep track of your data, so it can be used with public information, but never with private data.
The code examples shown below use jQuery.get() and jQuery.getJSON(), both are shorthand methods of jQuery.ajax()
CORS Anywhere
CORS Anywhere is a node.js proxy which adds CORS headers to the proxied request.
To use the API, just prefix the URL with the API URL. (Supports https: see github repository)
If you want to automatically enable cross-domain requests when needed, use the following snippet:
$.ajaxPrefilter( function (options) {
if (options.crossDomain && jQuery.support.cors) {
var http = (window.location.protocol === 'http:' ? 'http:' : 'https:');
options.url = http + '//cors-anywhere.herokuapp.com/' + options.url;
//options.url = "http://cors.corsproxy.io/url=" + options.url;
}
});
$.get(
'http://en.wikipedia.org/wiki/Cross-origin_resource_sharing',
function (response) {
console.log("> ", response);
$("#viewer").html(response);
});
Whatever Origin
Whatever Origin is a cross domain jsonp access. This is an open source alternative to anyorigin.com.
To fetch the data from google.com, you can use this snippet:
// It is good specify the charset you expect.
// You can use the charset you want instead of utf-8.
// See details for scriptCharset and contentType options:
// http://api.jquery.com/jQuery.ajax/#jQuery-ajax-settings
$.ajaxSetup({
scriptCharset: "utf-8", //or "ISO-8859-1"
contentType: "application/json; charset=utf-8"
});
$.getJSON('http://whateverorigin.org/get?url=' +
encodeURIComponent('http://google.com') + '&callback=?',
function (data) {
console.log("> ", data);
//If the expected response is text/plain
$("#viewer").html(data.contents);
//If the expected response is JSON
//var response = $.parseJSON(data.contents);
});
CORS Proxy
CORS Proxy is a simple node.js proxy to enable CORS request for any website.
It allows javascript code on your site to access resources on other domains that would normally be blocked due to the same-origin policy.
How does it work?
CORS Proxy takes advantage of Cross-Origin Resource Sharing, which is a feature that was added along with HTML 5. Servers can specify that they want browsers to allow other websites to request resources they host. CORS Proxy is simply an HTTP Proxy that adds a header to responses saying "anyone can request this".
This is another way to achieve the goal (see www.corsproxy.com). All you have to do is strip http:// and www. from the URL being proxied, and prepend the URL with www.corsproxy.com/
$.get(
'http://www.corsproxy.com/' +
'en.wikipedia.org/wiki/Cross-origin_resource_sharing',
function (response) {
console.log("> ", response);
$("#viewer").html(response);
});
CORS proxy browser
Recently I found this one, it involves various security oriented Cross Origin Remote Sharing utilities. But it is a black-box with Flash as backend.
You can see it in action here: CORS proxy browser
Get the source code on GitHub: koto/cors-proxy-browser
font size in html code
<html>
<table>
<tr>
<td style="padding-left: 5px;padding-bottom:3px; font-size:35px;"> <b>Datum:</b><br/>
November 2010 </td>
</table>
</html>
How to hide action bar before activity is created, and then show it again?
Try this, it works for me:
Below gets rid of activity's title bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
Below eliminates the notification bar to make the activity go full-screen
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
(Full Example Below)
Take note: These methods were called before we set the content view of our activity
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Sets Application to full screen by removing action bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_main);
// without this check, we would create a new fragment at each orientation change!
if (null == savedInstanceState)
createFragment();
}
jQuery click function doesn't work after ajax call?
When you use $('.deletelanguage').click()
to register an event handler it adds the handler to only those elements which exists in the dom when the code was executed
you need to use delegation based event handlers here
$(document).on('click', '.deletelanguage', function(){
alert("success");
});
Angular.js: set element height on page load
Combining matty-j suggestion with the snippet of the question, I ended up with this code focusing on resizing the grid after the data was loaded.
The HTML:
<div ng-grid="gridOptions" class="gridStyle"></div>
The directive:
angular.module('myApp.directives', [])
.directive('resize', function ($window) {
return function (scope, element) {
var w = angular.element($window);
scope.getWindowDimensions = function () {
return { 'h': w.height(), 'w': w.width() };
};
scope.$watch(scope.getWindowDimensions, function (newValue, oldValue) {
// resize Grid to optimize height
$('.gridStyle').height(newValue.h - 250);
}, true);
w.bind('resize', function () {
scope.$apply();
});
}
});
The controller:
angular.module('myApp').controller('Admin/SurveyCtrl', function ($scope, $routeParams, $location, $window, $timeout, Survey) {
// Retrieve data from the server
$scope.surveys = Survey.query(function(data) {
// Trigger resize event informing elements to resize according to the height of the window.
$timeout(function () {
angular.element($window).resize();
}, 0)
});
// Configure ng-grid.
$scope.gridOptions = {
data: 'surveys',
...
};
}
Set a Fixed div to 100% width of the parent container
You can use margin for .wrap container instead of padding for .wrapper:
body{ height:20000px }
#wrapper { padding: 0%; }
#wrap{
float: left;
position: relative;
margin: 10%;
width: 40%;
background:#ccc;
}
#fixed{
position:fixed;
width:inherit;
padding:0px;
height:10px;
background-color:#333;
}
jsfiddle
Printing column separated by comma using Awk command line
If your only requirement is to print the third field of every line, with each field delimited by a comma, you can use cut:
cut -d, -f3 file
-d,
sets the delimiter to a comma
-f3
specifies that only the third field is to be printed
Failed to decode downloaded font, OTS parsing error: invalid version tag + rails 4
I got the exact same error, and in my case it turned out to be because of a wrong path for the @font-face
declaration. The web inspector never complained with a 404 since the dev server we're using (live-server) was configured to serve up the default index.html on any 404:s. Without knowing any details about your setup, this could be a likely culprit.
Bootstrap select dropdown list placeholder
If you are initializing the select field through javascript, the following can be added to replace the default placeholder text
noneSelectedText: 'Insert Placeholder text'
example: if you have:
<select class='picker'></select>
in your javascript, you initialize the selectpicker like this
$('.picker').selectpicker({noneSelectedText: 'Insert Placeholder text'});
$("#form1").validate is not a function
I had this same issue. It turned out that I was loading the jQuery JavaScript file more than once on the page. This was due to included pages (or JSPs, in my case). Once I removed the duplicate reference to the jQuery js file, this error went away.
How do I show a console output/window in a forms application?
You can any time switch between type of applications, to console or windows. So, you will not write special logic to see the stdout. Also, when running application in debugger, you will see all the stdout in output window. You might also just add a breakpoint, and in breakpoint properties change "When Hit...", you can output any messages, and variables. Also you can check/uncheck "Continue execution", and your breakpoint will become square shaped. So, the breakpoint messages without changhing anything in the application in the debug output window.
Trying to handle "back" navigation button action in iOS
Try this code using VIewWillDisappear
method to detect the press of The back button of NavigationItem:
-(void) viewWillDisappear:(BOOL)animated
{
if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound)
{
// Navigation button was pressed. Do some stuff
[self.navigationController popViewControllerAnimated:NO];
}
[super viewWillDisappear:animated];
}
OR There is another way to get Action of the Navigation BAck button.
Create Custom button for UINavigationItem of back button .
For Ex:
In ViewDidLoad :
- (void)viewDidLoad
{
[super viewDidLoad];
UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle:@"Home" style:UIBarButtonItemStyleBordered target:self action:@selector(home:)];
self.navigationItem.leftBarButtonItem=newBackButton;
}
-(void)home:(UIBarButtonItem *)sender
{
[self.navigationController popToRootViewControllerAnimated:YES];
}
Swift :
override func willMoveToParentViewController(parent: UIViewController?)
{
if parent == nil
{
// Back btn Event handler
}
}
How to convert String to DOM Document object in java?
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document document = db.parse(new ByteArrayInputStream(xmlString.getBytes("UTF-8"))); //remove the parameter UTF-8 if you don't want to specify the Encoding type.
this works well for me even though the XML structure is complex.
And please make sure your xmlString is valid for XML, notice the escape character should be added "\" at the front.
The main problem might not come from the attributes.
How to add a “readonly” attribute to an <input>?
Check the code below:
<input id="mail">
<script>
document.getElementById('mail').readOnly = true; // makes input readonline
document.getElementById('mail').readOnly = false; // makes input writeable again
</script>
GUI-based or Web-based JSON editor that works like property explorer
Update: In an effort to answer my own question, here is what I've been able to uncover so far. If anyone else out there has something, I'd still be interested to find out more.
Based on JSON Schema
Commercial (No endorsement intended or implied, may or may not meet requirement)
jQuery
YAML
See Also
Best way to convert IList or IEnumerable to Array
In case you don't have Linq, I solved it the following way:
private T[] GetArray<T>(IList<T> iList) where T: new()
{
var result = new T[iList.Count];
iList.CopyTo(result, 0);
return result;
}
Hope it helps
Include PHP file into HTML file
You'll have to configure the server to interpret .html
files as .php
files. This configuration is different depending on the server software. This will also add an extra step to the server and will slow down response on all your pages and is probably not ideal.
How to save S3 object to a file using boto3
boto3 now has a nicer interface than the client:
resource = boto3.resource('s3')
my_bucket = resource.Bucket('MyBucket')
my_bucket.download_file(key, local_filename)
This by itself isn't tremendously better than the client
in the accepted answer (although the docs say that it does a better job retrying uploads and downloads on failure) but considering that resources are generally more ergonomic (for example, the s3 bucket and object resources are nicer than the client methods) this does allow you to stay at the resource layer without having to drop down.
Resources
generally can be created in the same way as clients, and they take all or most of the same arguments and just forward them to their internal clients.
Function overloading in Python: Missing
As unwind noted, keyword arguments with default values can go a long way.
I'll also state that in my opinion, it goes against the spirit of Python to worry a lot about what types are passed into methods. In Python, I think it's more accepted to use duck typing -- asking what an object can do, rather than what it is.
Thus, if your method may accept a string or a tuple, you might do something like this:
def print_names(names):
"""Takes a space-delimited string or an iterable"""
try:
for name in names.split(): # string case
print name
except AttributeError:
for name in names:
print name
Then you could do either of these:
print_names("Ryan Billy")
print_names(("Ryan", "Billy"))
Although an API like that sometimes indicates a design problem.
Clearing content of text file using php
To add button you may use either jQuery libraries or simple Javascript script as shown below:
HTML link or button:
<a href="#" onClick="goclear()" id="button">click event</a>
Javascript:
<script type="text/javascript">
var btn = document.getElementById('button');
function goclear() {
alert("Handler called. Page will redirect to clear.php");
document.location.href = "clear.php";
};
</script>
Use PHP to clear a file content. For instance you can use the fseek($fp, 0); or ftruncate ( resource $file , int $size ) as below:
<?php
//open file to write
$fp = fopen("/tmp/file.txt", "r+");
// clear content to 0 bits
ftruncate($fp, 0);
//close file
fclose($fp);
?>
Redirect PHP - you can use header ( string $string [, bool $replace = true [, int $http_response_code ]] )
<?php
header('Location: getbacktoindex.html');
?>
I hope it's help.
CSS - How to Style a Selected Radio Buttons Label?
You are using an adjacent sibling selector (+
) when the elements are not siblings. The label is the parent of the input, not it's sibling.
CSS has no way to select an element based on it's descendents (nor anything that follows it).
You'll need to look to JavaScript to solve this.
Alternatively, rearrange your markup:
<input id="foo"><label for="foo">…</label>
biggest integer that can be stored in a double
You need to look at the size of the mantissa. An IEEE 754 64 bit floating point number (which has 52 bits, plus 1 implied) can exactly represent integers with an absolute value of less than or equal to 2^53.
Test process.env with Jest
In my opinion, it's much cleaner and easier to understand if you extract the retrieval of environment variables into a utility (you probably want to include a check to fail fast if an environment variable is not set anyway), and then you can just mock the utility.
// util.js
exports.getEnv = (key) => {
const value = process.env[key];
if (value === undefined) {
throw new Error(`Missing required environment variable ${key}`);
}
return value;
};
// app.test.js
const util = require('./util');
jest.mock('./util');
util.getEnv.mockImplementation(key => `fake-${key}`);
test('test', () => {...});
How to specify Memory & CPU limit in docker compose version 3
I know the topic is a bit old and seems stale, but anyway I was able to use these options:
deploy:
resources:
limits:
cpus: '0.001'
memory: 50M
when using 3.7 version of docker-compose
What helped in my case, was using this command:
docker-compose --compatibility up
--compatibility
flag stands for (taken from the documentation):
If set, Compose will attempt to convert deploy keys in v3 files to
their non-Swarm equivalent
Think it's great, that I don't have to revert my docker-compose file back to v2.
remove space between paragraph and unordered list
Every browser has some default styles that apply to a number of HTML elements, likes p and ul.
The space you mention is likely created because of the default margin and padding of your browser. You can reset these though:
p { margin: 0; padding: 0; }
ul { margin: 0; padding: 0; }
You could also reset all default margins and paddings:
* { margin: 0; padding: 0; }
I suggest you take a look at normalize.css: http://necolas.github.com/normalize.css/
What are the best JVM settings for Eclipse?
If you are using Linux + Sun JDK/JRE 32bits, change the "-vm" to:
-vm
[your_jdk_folder]/jre/lib/i386/client/libjvm.so
If you are using Linux + Sun JDK/JRE 64bits, change the "-vm" to:
-vm
[your_jdk_folder]/jre/lib/amd64/server/libjvm.so
That's working fine for me on Ubuntu 8.10 and 9.04
strcpy() error in Visual studio 2012
I had to use strcpy_s and it worked.
#include "stdafx.h"
#include<iostream>
#include<string>
using namespace std;
struct student
{
char name[30];
int age;
};
int main()
{
struct student s1;
char myname[30] = "John";
strcpy_s (s1.name, strlen(myname) + 1 ,myname );
s1.age = 21;
cout << " Name: " << s1.name << " age: " << s1.age << endl;
return 0;
}
Python Pandas: How to read only first n rows of CSV files in?
If you only want to read the first 999,999 (non-header) rows:
read_csv(..., nrows=999999)
If you only want to read rows 1,000,000 ... 1,999,999
read_csv(..., skiprows=1000000, nrows=999999)
nrows : int, default None Number of rows of file to read. Useful for
reading pieces of large files*
skiprows : list-like or integer
Row numbers to skip (0-indexed) or number of rows to skip (int) at the start of the file
and for large files, you'll probably also want to use chunksize:
chunksize : int, default None
Return TextFileReader object for iteration
pandas.io.parsers.read_csv documentation
Runnable with a parameter?
You could put it in a function.
String paramStr = "a parameter";
Runnable myRunnable = createRunnable(paramStr);
private Runnable createRunnable(final String paramStr){
Runnable aRunnable = new Runnable(){
public void run(){
someFunc(paramStr);
}
};
return aRunnable;
}
(When I used this, my parameter was an integer ID, which I used to make a hashmap of ID --> myRunnables. That way, I can use the hashmap to post/remove different myRunnable objects in a handler.)
Android SQLite: Update Statement
You can use the code below.
String strFilter = "_id=" + Id;
ContentValues args = new ContentValues();
args.put(KEY_TITLE, title);
myDB.update("titles", args, strFilter, null);
adb shell su works but adb root does not
adbd
has a compilation flag/option to enable root access: ALLOW_ADBD_ROOT=1
.
Up to Android 9: If adbd
on your device is compiled without that flag, it will always drop privileges when starting up and thus "adb root" will not help at all.
I had to patch the calls to setuid()
, setgid()
, setgroups()
and the capability drops out of the binary myself to get a permanently rooted adbd on my ebook reader.
With Android 10 this changed; when the phone/tablet is unlocked (ro.boot.verifiedbootstate == "orange"
), then adb root mode is possible in any case.
Override browser form-filling and input highlighting with HTML/CSS
The REAL problem here is that Webkit (Safari, Chrome, ...) has a bug. When there's more than one [form] on the page, each with an [input type="text" name="foo" ...] (i.e. with the same value for the attribute 'name'), then when the user returns to the page the autofill will be done in the input field of the FIRST [form] on the page, not in the [form] that was sent. The second time, the NEXT [form] will be autofilled, and so on. Only [form] with an input text field with the SAME name will be affected.
This should be reported to the Webkit developers.
Opera autofills the right [form].
Firefox and IE doesn't autofill.
So, I say again: this is a bug in Webkit.
XMLHttpRequest cannot load an URL with jQuery
Fiddle with 3 working solutions in action.
Given an external JSON:
myurl = 'http://wikidata.org/w/api.php?action=wbgetentities&sites=frwiki&titles=France&languages=zh-hans|zh-hant|fr&props=sitelinks|labels|aliases|descriptions&format=json'
Solution 1: $.ajax() + jsonp:
$.ajax({
dataType: "jsonp",
url: myurl ,
}).done(function ( data ) {
// do my stuff
});
Solution 2: $.ajax()+json+&calback=?:
$.ajax({
dataType: "json",
url: myurl + '&callback=?',
}).done(function ( data ) {
// do my stuff
});
Solution 3: $.getJSON()+calback=?:
$.getJSON( myurl + '&callback=?', function(data) {
// do my stuff
});
Documentations: http://api.jquery.com/jQuery.ajax/ , http://api.jquery.com/jQuery.getJSON/
UnicodeDecodeError, invalid continuation byte
Because UTF-8 is multibyte and there is no char corresponding to your combination of \xe9
plus following space.
Why should it succeed in both utf-8 and latin-1?
Here how the same sentence should be in utf-8:
>>> o.decode('latin-1').encode("utf-8")
'a test of \xc3\xa9 char'
Is there a concurrent List in Java's JDK?
Mostly if you need a concurrent list it is inside a model object (as you should not use abstract data types like a list to represent a node in a application model graph) or it is part of a particular service, you can synchronize the access yourself.
class MyClass {
List<MyType> myConcurrentList = new ArrayList<>();
void myMethod() {
synchronzied(myConcurrentList) {
doSomethingWithList;
}
}
}
Often this is enough to get you going. If you need to iterate, iterate over a copy of the list not the list itself and only synchronize the part where you copy the list not while you are iterating over it.
Also when concurrently working on a list you usually do something more than just adding or removing or copying, meaning that the operation becomes meaningful enough to warrent its own method and the list becomes member of a special class representing just this particular list with thread safe behavior.
Even if I agree that a concurrent list implementation is needed and Vector / Collections.sychronizeList(list) do not do the trick as for sure you need something like compareAndAdd or compareAndRemove or get(..., ifAbsentDo), even if you have a ConcurrentList implementation developers often introduce bugs by not considering what is the true transaction when working with a concurrent lists (and maps).
These scenarios where the transactions are too small for what the intended purpose of the interaction with a concurrent ADT (abstract data type) always lead to me hide the list in a special class and synchronizing access to this class objects method using the synchronized on the method level. Its the only way to be sure that the transactions are correct.
I have seen too many bugs to do it any other way - at least if the code is important and handles something like money or security or guarantees some quality of service measures (e.g sending message at least once and only once).
Error handling in C code
Here's a simple program to demonstrate the first 2 bullets of Nils Pipenbrinck's answer here.
His first 2 bullets are:
store all possible error-states in one typedef'ed enum and use it in your lib. Don't just return ints or even worse, mix ints or different enumerations with return-codes.
provide a function that converts errors into something human readable. Can be simple. Just error-enum in, const char* out.
Assume you have written a module named mymodule
. First, in mymodule.h, you define your enum-based error codes, and you write some error strings which correspond to these codes. Here I am using an array of C strings (char *
), which only works well if your first enum-based error code has value 0, and you don't manipulate the numbers thereafter. If you do use error code numbers with gaps or other starting values, you'll simply have to change from using a mapped C-string array (as I do below) to using a function which uses a switch statement or if / else if statements to map from enum error codes to printable C strings (which I don't demonstrate). The choice is yours.
mymodule.h
/// @brief Error codes for library "mymodule"
typedef enum mymodule_error_e
{
/// No error
MYMODULE_ERROR_OK = 0,
/// Invalid arguments (ex: NULL pointer where a valid pointer is required)
MYMODULE_ERROR_INVARG,
/// Out of memory (RAM)
MYMODULE_ERROR_NOMEM,
/// Make up your error codes as you see fit
MYMODULE_ERROR_MYERROR,
// etc etc
/// Total # of errors in this list (NOT AN ACTUAL ERROR CODE);
/// NOTE: that for this to work, it assumes your first error code is value 0 and you let it naturally
/// increment from there, as is done above, without explicitly altering any error values above
MYMODULE_ERROR_COUNT,
} mymodule_error_t;
// Array of strings to map enum error types to printable strings
// - see important NOTE above!
const char* const MYMODULE_ERROR_STRS[] =
{
"MYMODULE_ERROR_OK",
"MYMODULE_ERROR_INVARG",
"MYMODULE_ERROR_NOMEM",
"MYMODULE_ERROR_MYERROR",
};
// To get a printable error string
const char* mymodule_error_str(mymodule_error_t err);
// Other functions in mymodule
mymodule_error_t mymodule_func1(void);
mymodule_error_t mymodule_func2(void);
mymodule_error_t mymodule_func3(void);
mymodule.c contains my mapping function to map from enum error codes to printable C strings:
mymodule.c
#include <stdio.h>
/// @brief Function to get a printable string from an enum error type
/// @param[in] err a valid error code for this module
/// @return A printable C string corresponding to the error code input above, or NULL if an invalid error code
/// was passed in
const char* mymodule_error_str(mymodule_error_t err)
{
const char* err_str = NULL;
// Ensure error codes are within the valid array index range
if (err >= MYMODULE_ERROR_COUNT)
{
goto done;
}
err_str = MYMODULE_ERROR_STRS[err];
done:
return err_str;
}
// Let's just make some empty dummy functions to return some errors; fill these in as appropriate for your
// library module
mymodule_error_t mymodule_func1(void)
{
return MYMODULE_ERROR_OK;
}
mymodule_error_t mymodule_func2(void)
{
return MYMODULE_ERROR_INVARG;
}
mymodule_error_t mymodule_func3(void)
{
return MYMODULE_ERROR_MYERROR;
}
main.c contains a test program to demonstrate calling some functions and printing some error codes from them:
main.c
#include <stdio.h>
int main()
{
printf("Demonstration of enum-based error codes in C (or C++)\n");
printf("err code from mymodule_func1() = %s\n", mymodule_error_str(mymodule_func1()));
printf("err code from mymodule_func2() = %s\n", mymodule_error_str(mymodule_func2()));
printf("err code from mymodule_func3() = %s\n", mymodule_error_str(mymodule_func3()));
return 0;
}
Output:
Demonstration of enum-based error codes in C (or C++)
err code from mymodule_func1() = MYMODULE_ERROR_OK
err code from mymodule_func2() = MYMODULE_ERROR_INVARG
err code from mymodule_func3() = MYMODULE_ERROR_MYERROR
References:
You can run this code yourself here: https://onlinegdb.com/ByEbKLupS.
What online brokers offer APIs?
There are a few. I was looking into MBTrading for a friend. I didn't get too far, as my friend lost interest. Seemed relatively straigt forward with a C# and VB.Net SDK. They had some docs and everything. This was ~6 months ago, so it may be better (or worse) by now.
IIRC, you can create a demo account for free. I don't remember all the details, but it let you connect to their test server and pull quotes and make fake trades and such to get your software fine tuned.
Don't know much about cost for an actual account or anything.
Pytorch tensor to numpy array
Your question is very poorly worded. Your code (sort of) already does what you want. What exactly are you confused about? x.numpy()
answer the original title of your question:
Pytorch tensor to numpy array
you need improve your question starting with your title.
Anyway, just in case this is useful to others. You might need to call detach for your code to work. e.g.
RuntimeError: Can't call numpy() on Variable that requires grad.
So call .detach()
. Sample code:
# creating data and running through a nn and saving it
import torch
import torch.nn as nn
from pathlib import Path
from collections import OrderedDict
import numpy as np
path = Path('~/data/tmp/').expanduser()
path.mkdir(parents=True, exist_ok=True)
num_samples = 3
Din, Dout = 1, 1
lb, ub = -1, 1
x = torch.torch.distributions.Uniform(low=lb, high=ub).sample((num_samples, Din))
f = nn.Sequential(OrderedDict([
('f1', nn.Linear(Din,Dout)),
('out', nn.SELU())
]))
y = f(x)
# save data
y.numpy()
x_np, y_np = x.detach().cpu().numpy(), y.detach().cpu().numpy()
np.savez(path / 'db', x=x_np, y=y_np)
print(x_np)
cpu goes after detach. See: https://discuss.pytorch.org/t/should-it-really-be-necessary-to-do-var-detach-cpu-numpy/35489/5
Also I won't make any comments on the slicking since that is off topic and that should not be the focus of your question. See this:
Understanding slice notation
.map() a Javascript ES6 Map?
If you don't want to convert the entire Map into an array beforehand, and/or destructure key-value arrays, you can use this silly function:
_x000D_
_x000D_
/**_x000D_
* Map over an ES6 Map._x000D_
*_x000D_
* @param {Map} map_x000D_
* @param {Function} cb Callback. Receives two arguments: key, value._x000D_
* @returns {Array}_x000D_
*/_x000D_
function mapMap(map, cb) {_x000D_
let out = new Array(map.size);_x000D_
let i = 0;_x000D_
map.forEach((val, key) => {_x000D_
out[i++] = cb(key, val);_x000D_
});_x000D_
return out;_x000D_
}_x000D_
_x000D_
let map = new Map([_x000D_
["a", 1],_x000D_
["b", 2],_x000D_
["c", 3]_x000D_
]);_x000D_
_x000D_
console.log(_x000D_
mapMap(map, (k, v) => `${k}-${v}`).join(', ')_x000D_
); // a-1, b-2, c-3
_x000D_
_x000D_
_x000D_
How to assign multiple classes to an HTML container?
To assign multiple classes to an html element, include both class names within the quotations of the class attribute and have them separated by a space:
<article class="column wrapper">
In the above example, column
and wrapper
are two separate css classes, and both of their properties will be applied to the article
element.
What do the return values of Comparable.compareTo mean in Java?
Official Definition
From the reference docs of Comparable.compareTo(T):
Compares this object with the
specified object for order. Returns a
negative integer, zero, or a positive
integer as this object is less than,
equal to, or greater than the
specified object.
The implementor must ensure
sgn(x.compareTo(y)) ==
-sgn(y.compareTo(x)) for all x and y. (This implies that x.compareTo(y) must
throw an exception iff y.compareTo(x)
throws an exception.)
The implementor must also ensure that
the relation is transitive:
(x.compareTo(y)>0 && y.compareTo(z)>0)
implies x.compareTo(z)>0.
Finally, the implementor must ensure
that x.compareTo(y)==0 implies that
sgn(x.compareTo(z)) ==
sgn(y.compareTo(z)), for all z.
It is strongly recommended, but not
strictly required that
(x.compareTo(y)==0) == (x.equals(y)).
Generally speaking, any class that
implements the Comparable interface
and violates this condition should
clearly indicate this fact. The
recommended language is "Note: this
class has a natural ordering that is
inconsistent with equals."
In the foregoing description, the
notation sgn(expression) designates
the mathematical signum function,
which is defined to return one of -1,
0, or 1 according to whether the value
of expression is negative, zero or
positive.
My Version
In short:
this.compareTo(that)
returns
- a negative int if this < that
- 0 if this == that
- a positive int if this > that
where the implementation of this method determines the actual semantics of <
>
and ==
(I don't mean ==
in the sense of java's object identity operator)
Examples
"abc".compareTo("def")
will yield something smaller than 0 as abc
is alphabetically before def
.
Integer.valueOf(2).compareTo(Integer.valueOf(1))
will yield something larger than 0 because 2 is larger than 1.
Some additional points
Note: It is good practice for a class that implements Comparable to declare the semantics of it's compareTo() method in the javadocs.
Note: you should read at least one of the following:
Warning: you should never rely on the return values of compareTo being -1
, 0
and 1
. You should always test for x < 0
, x == 0
, x > 0
, respectively.
What design patterns are used in Spring framework?
Service Locator Pattern - ServiceLocatorFactoryBean keeps information of all the beans in the context. When client code asks for a service (bean) using name, it simply locates that bean in the context and returns it. Client code does not need to write spring related code to locate a bean.
how to display progress while loading a url to webview in android?
Check out the sample code. It help you.
private ProgressBar progressBar;
progressBar=(ProgressBar)findViewById(R.id.webloadProgressBar);
WebView urlWebView= new WebView(Context);
urlWebView.setWebViewClient(new AppWebViewClients(progressBar));
urlWebView.getSettings().setJavaScriptEnabled(true);
urlWebView.loadUrl(detailView.getUrl());
public class AppWebViewClients extends WebViewClient {
private ProgressBar progressBar;
public AppWebViewClients(ProgressBar progressBar) {
this.progressBar=progressBar;
progressBar.setVisibility(View.VISIBLE);
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// TODO Auto-generated method stub
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
// TODO Auto-generated method stub
super.onPageFinished(view, url);
progressBar.setVisibility(View.GONE);
}
}
Thanks.
delete image from folder PHP
There are a few routes. One, the most simple, would involve making that into a form; when it submits you react to POST data and delete the image using unlink
DISCLAIMER: This is not secure. An attacker could use this code to delete any file on your server. You must expand on this demonstration code to add some measure of security, otherwise you can expect bad things.
Each image's display markup would contain a form something like this:
echo '<form method="post">';
echo '<input type="hidden" value="'.$file.'" name="delete_file" />';
echo '<input type="submit" value="Delete image" />';
echo '</form>';
...and at at the top of that same PHP file:
if (array_key_exists('delete_file', $_POST)) {
$filename = $_POST['delete_file'];
if (file_exists($filename)) {
unlink($filename);
echo 'File '.$filename.' has been deleted';
} else {
echo 'Could not delete '.$filename.', file does not exist';
}
}
// existing code continues below...
You can elaborate on this by using javascript: instead of submitting the form, you could send an AJAX request. The server-side code would look rather similar to this.
Documentation and Related Reading
Making TextView scrollable on Android
All that is really necessary is the setMovementMethod(). Here's an example using a LinearLayout.
File main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id="@+id/tv1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="@string/hello"
/>
</LinearLayout>
File WordExtractTest.java
public class WordExtractTest extends Activity {
TextView tv1;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv1 = (TextView)findViewById(R.id.tv1);
loadDoc();
}
private void loadDoc() {
String s = "";
for(int x=0; x<=100; x++) {
s += "Line: " + String.valueOf(x) + "\n";
}
tv1.setMovementMethod(new ScrollingMovementMethod());
tv1.setText(s);
}
}
How to include scripts located inside the node_modules folder?
I didn't find any clean solutions (I don't want to expose the source of all my node_modules) so I just wrote a Powershell script to copy them:
$deps = "leaflet", "leaflet-search", "material-components-web"
foreach ($dep in $deps) {
Copy-Item "node_modules/$dep/dist" "static/$dep" -Recurse
}
DynamoDB vs MongoDB NoSQL
Short answer: Start with SQL and add NoSQL only when/if needed. (unless you don't need anything beyond very simple queries)
My personal experience: I haven't used MongoDB for queries but as of April 2015 DynamoDB is still very crippled when it comes to anything beyond the most basic key/value queries. I love it for the basic stuff but if you want query language then look to a real SQL database solution.
In DynamoDB you can query on a hash or on a hash and range key, and you can have multiple secondary global indexes. I'm doing queries on a single table with 4 possible filter parameters and sorting the results, this is supported (barely) through the use of the global secondary indexes with filter expressions. The problem comes in when you try to get the total results matching the filter, you can't just search for the first 10 items matching the filter, but rather it checks 10 items and you may get 0 valid results forcing you to keep re-scanning from the continue key - pain in the neck and consumes too much of your table read quota for a simple scenario.
To be specific about the limit problem with filters in the query, this is from the docs (http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html#ScanQueryLimit):
In a response, DynamoDB returns all the matching results within
the scope of the Limit value. For example, if you issue a Query
or a Scan request with a Limit value of 6 and without a filter
expression, the operation returns the first six items in the
table that match the request parameters. If you also supply a
FilterExpression, the operation returns the items within the
first six items in the table that match the filter requirements.
My conclusion is that queries involving FilterExpressions are only usable on very rare occasions and are not scalable because each query can easily read most or all of your of your table which consumes far too many DynamoDB read units. Once you use too many read units you'll get throttled and see poor performance.
Expert opinion: In the AWS summit on Apr 9, 2015 Brett Hollman, Manager, Solutions Architecture, AWS in his talk on scalling to your first 10 million users advocates starting with a SQL database and then using NoSQL only when and if it makes sense. Because sooner or later you'll probably need a SQL server somewhere in your stack. His slides are here: http://www.slideshare.net/AmazonWebServices/deep-dive-scaling-up-to-your-first-10-million-users
See slide 28.
How do you setLayoutParams() for an ImageView?
An ImageView gets setLayoutParams from View which uses ViewGroup.LayoutParams. If you use that, it will crash in most cases so you should use getLayoutParams() which is in View.class. This will inherit the parent View of the ImageView and will work always. You can confirm this here: ImageView extends view
Assuming you have an ImageView defined as 'image_view' and the width/height int defined as 'thumb_size'
The best way to do this:
ViewGroup.LayoutParams iv_params_b = image_view.getLayoutParams();
iv_params_b.height = thumb_size;
iv_params_b.width = thumb_size;
image_view.setLayoutParams(iv_params_b);
MySQL foreign key constraints, cascade delete
I think (I'm not certain) that foreign key constraints won't do precisely what you want given your table design. Perhaps the best thing to do is to define a stored procedure that will delete a category the way you want, and then call that procedure whenever you want to delete a category.
CREATE PROCEDURE `DeleteCategory` (IN category_ID INT)
LANGUAGE SQL
NOT DETERMINISTIC
MODIFIES SQL DATA
SQL SECURITY DEFINER
BEGIN
DELETE FROM
`products`
WHERE
`id` IN (
SELECT `products_id`
FROM `categories_products`
WHERE `categories_id` = category_ID
)
;
DELETE FROM `categories`
WHERE `id` = category_ID;
END
You also need to add the following foreign key constraints to the linking table:
ALTER TABLE `categories_products` ADD
CONSTRAINT `Constr_categoriesproducts_categories_fk`
FOREIGN KEY `categories_fk` (`categories_id`) REFERENCES `categories` (`id`)
ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `Constr_categoriesproducts_products_fk`
FOREIGN KEY `products_fk` (`products_id`) REFERENCES `products` (`id`)
ON DELETE CASCADE ON UPDATE CASCADE
The CONSTRAINT clause can, of course, also appear in the CREATE TABLE statement.
Having created these schema objects, you can delete a category and get the behaviour you want by issuing CALL DeleteCategory(category_ID)
(where category_ID is the category to be deleted), and it will behave how you want. But don't issue a normal DELETE FROM
query, unless you want more standard behaviour (i.e. delete from the linking table only, and leave the products
table alone).
How to set JVM parameters for Junit Unit Tests?
An eclipse specific alternative limited to the java.library.path JVM parameter allows to set it for a specific source folder rather than for the whole jdk as proposed in another response:
- select the source folder in which the program to start resides (usually source/test/java)
- type alt enter to open Properties page for that folder
- select native in the left panel
- Edit the native path. The path can be absolute or relative to the workspace, the second being more change resilient.
For those interested on detail on why maven argline tag should be preferred to the systemProperties one, look, for example:
Pick up native JNI files in Maven test (lwjgl)
How to concatenate strings in twig
Whenever you need to use a filter with a concatenated string (or a basic math operation) you should wrap it with ()'s. Eg.:
{{ ('http://' ~ app.request.host) | url_encode }}
Adding integers to an int array
An array doesn't have an add method. You assign a value to an element of the array with num[i]=value;
.
public static void main(String[] args) {
int[] num = new int[args.length];
for (int i=0; i < num.length; i++){
int neki = Integer.parseInt(args[i]);
num[i]=neki;
}
}
How to do tag wrapping in VS code?
Embedded Emmet could do the trick:
- Select text (optional)
- Open command palette (usually Ctrl+Shift+P)
- Execute
Emmet: Wrap with Abbreviation
- Enter a tag
div
(or an abbreviation .wrapper>p
)
- Hit Enter
Command can be assigned to a keybinding.
This thing even supports passing arguments:
{
"key": "ctrl+shift+9",
"command": "editor.emmet.action.wrapWithAbbreviation",
"when": "editorHasSelection",
"args": {
"abbreviation": "span"
}
},
Use it like this:
span.myCssClass
span#myCssId
b
b.myCssClass
How to change text and background color?
There is no (standard) cross-platform way to do this. On windows, try using conio.h
.
It has the:
textcolor(); // and
textbackground();
functions.
For example:
textcolor(RED);
cprintf("H");
textcolor(BLUE);
cprintf("e");
// and so on.
How do you get the index of the current iteration of a foreach loop?
You can write your loop like this:
var s = "ABCDEFG";
foreach (var item in s.GetEnumeratorWithIndex())
{
System.Console.WriteLine("Character: {0}, Position: {1}", item.Value, item.Index);
}
After adding the following struct and extension method.
The struct and extension method encapsulate Enumerable.Select functionality.
public struct ValueWithIndex<T>
{
public readonly T Value;
public readonly int Index;
public ValueWithIndex(T value, int index)
{
this.Value = value;
this.Index = index;
}
public static ValueWithIndex<T> Create(T value, int index)
{
return new ValueWithIndex<T>(value, index);
}
}
public static class ExtensionMethods
{
public static IEnumerable<ValueWithIndex<T>> GetEnumeratorWithIndex<T>(this IEnumerable<T> enumerable)
{
return enumerable.Select(ValueWithIndex<T>.Create);
}
}
What is the difference between print and puts?
The API docs give some good hints:
print() ? nil
print(obj, ...) ? nil
Writes the given object(s) to ios. Returns nil
.
The stream must be opened for writing. Each given object that isn't a
string will be converted by calling its to_s
method. When
called without arguments, prints the contents of $_
.
If the output field separator ($,
) is not nil
, it
is inserted between objects. If the output record separator
($\
) is not nil
, it is appended to the output.
...
puts(obj, ...) ? nil
Writes the given object(s) to ios. Writes a newline after any that
do not already end with a newline sequence. Returns nil
.
The stream must be opened for writing. If called with an array argument,
writes each element on a new line. Each given object that isn't a
string or array will be converted by calling its to_s
method.
If called without arguments, outputs a single newline.
Experimenting a little with the points given above, the differences seem to be:
Called with multiple arguments, print
separates them by the 'output field separator' $,
(which defaults to nothing) while puts
separates them by newlines. puts
also puts a newline after the final argument, while print
does not.
2.1.3 :001 > print 'hello', 'world'
helloworld => nil
2.1.3 :002 > puts 'hello', 'world'
hello
world
=> nil
2.1.3 :003 > $, = 'fanodd'
=> "fanodd"
2.1.3 :004 > print 'hello', 'world'
hellofanoddworld => nil
2.1.3 :005 > puts 'hello', 'world'
hello
world
=> nil
puts
automatically unpacks arrays, while print
does not:
2.1.3 :001 > print [1, [2, 3]], [4]
[1, [2, 3]][4] => nil
2.1.3 :002 > puts [1, [2, 3]], [4]
1
2
3
4
=> nil
print
with no arguments prints $_
(the last thing read by gets
), while puts
prints a newline:
2.1.3 :001 > gets
hello world
=> "hello world\n"
2.1.3 :002 > puts
=> nil
2.1.3 :003 > print
hello world
=> nil
print
writes the output record separator $\
after whatever it prints, while puts
ignores this variable:
mark@lunchbox:~$ irb
2.1.3 :001 > $\ = 'MOOOOOOO!'
=> "MOOOOOOO!"
2.1.3 :002 > puts "Oink! Baa! Cluck! "
Oink! Baa! Cluck!
=> nil
2.1.3 :003 > print "Oink! Baa! Cluck! "
Oink! Baa! Cluck! MOOOOOOO! => nil
ES6 exporting/importing in index file
Too late but I want to share the way that I resolve it.
Having model
file which has two named export:
export { Schema, Model };
and having controller
file which has the default export:
export default Controller;
I exposed in the index
file in this way:
import { Schema, Model } from './model';
import Controller from './controller';
export { Schema, Model, Controller };
and assuming that I want import all of them:
import { Schema, Model, Controller } from '../../path/';
Show and hide a View with a slide up/down animation
if (filter_section.getVisibility() == View.GONE) {
filter_section.animate()
.translationY(filter_section.getHeight()).alpha(1.0f)
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationStart(Animator animation) {
super.onAnimationStart(animation);
filter_section.setVisibility(View.VISIBLE);
filter_section.setAlpha(0.0f);
}
});
} else {
filter_section.animate()
.translationY(0).alpha(0.0f)
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
filter_section.setVisibility(View.GONE);
}
});
}
How does paintComponent work?
Two things you can do here:
- Read Painting in AWT and Swing
- Use a debugger and put a breakpoint in the paintComponent method. Then travel up the stacktrace and see how provides the Graphics parameter.
Just for info, here is the stacktrace that I got from the example of code I posted at the end:
Thread [AWT-EventQueue-0] (Suspended (breakpoint at line 15 in TestPaint))
TestPaint.paintComponent(Graphics) line: 15
TestPaint(JComponent).paint(Graphics) line: 1054
JPanel(JComponent).paintChildren(Graphics) line: 887
JPanel(JComponent).paint(Graphics) line: 1063
JLayeredPane(JComponent).paintChildren(Graphics) line: 887
JLayeredPane(JComponent).paint(Graphics) line: 1063
JLayeredPane.paint(Graphics) line: 585
JRootPane(JComponent).paintChildren(Graphics) line: 887
JRootPane(JComponent).paintToOffscreen(Graphics, int, int, int, int, int, int) line: 5228
RepaintManager$PaintManager.paintDoubleBuffered(JComponent, Image, Graphics, int, int, int, int) line: 1482
RepaintManager$PaintManager.paint(JComponent, JComponent, Graphics, int, int, int, int) line: 1413
RepaintManager.paint(JComponent, JComponent, Graphics, int, int, int, int) line: 1206
JRootPane(JComponent).paint(Graphics) line: 1040
GraphicsCallback$PaintCallback.run(Component, Graphics) line: 39
GraphicsCallback$PaintCallback(SunGraphicsCallback).runOneComponent(Component, Rectangle, Graphics, Shape, int) line: 78
GraphicsCallback$PaintCallback(SunGraphicsCallback).runComponents(Component[], Graphics, int) line: 115
JFrame(Container).paint(Graphics) line: 1967
JFrame(Window).paint(Graphics) line: 3867
RepaintManager.paintDirtyRegions(Map<Component,Rectangle>) line: 781
RepaintManager.paintDirtyRegions() line: 728
RepaintManager.prePaintDirtyRegions() line: 677
RepaintManager.access$700(RepaintManager) line: 59
RepaintManager$ProcessingRunnable.run() line: 1621
InvocationEvent.dispatch() line: 251
EventQueue.dispatchEventImpl(AWTEvent, Object) line: 705
EventQueue.access$000(EventQueue, AWTEvent, Object) line: 101
EventQueue$3.run() line: 666
EventQueue$3.run() line: 664
AccessController.doPrivileged(PrivilegedAction<T>, AccessControlContext) line: not available [native method]
ProtectionDomain$1.doIntersectionPrivilege(PrivilegedAction<T>, AccessControlContext, AccessControlContext) line: 76
EventQueue.dispatchEvent(AWTEvent) line: 675
EventDispatchThread.pumpOneEventForFilters(int) line: 211
EventDispatchThread.pumpEventsForFilter(int, Conditional, EventFilter) line: 128
EventDispatchThread.pumpEventsForHierarchy(int, Conditional, Component) line: 117
EventDispatchThread.pumpEvents(int, Conditional) line: 113
EventDispatchThread.pumpEvents(Conditional) line: 105
EventDispatchThread.run() line: 90
The Graphics parameter comes from here:
RepaintManager.paintDirtyRegions(Map) line: 781
The snippet involved is the following:
Graphics g = JComponent.safelyGetGraphics(
dirtyComponent, dirtyComponent);
// If the Graphics goes away, it means someone disposed of
// the window, don't do anything.
if (g != null) {
g.setClip(rect.x, rect.y, rect.width, rect.height);
try {
dirtyComponent.paint(g); // This will eventually call paintComponent()
} finally {
g.dispose();
}
}
If you take a look at it, you will see that it retrieve the graphics from the JComponent itself (indirectly with javax.swing.JComponent.safelyGetGraphics(Component, Component)
) which itself takes it eventually from its first "Heavyweight parent" (clipped to the component bounds) which it self takes it from its corresponding native resource.
Regarding the fact that you have to cast the Graphics
to a Graphics2D
, it just happens that when working with the Window Toolkit, the Graphics
actually extends Graphics2D
, yet you could use other Graphics
which do "not have to" extends Graphics2D
(it does not happen very often but AWT/Swing allows you to do that).
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
class TestPaint extends JPanel {
public TestPaint() {
setBackground(Color.WHITE);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawOval(0, 0, getWidth(), getHeight());
}
public static void main(String[] args) {
JFrame jFrame = new JFrame();
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jFrame.setSize(300, 300);
jFrame.add(new TestPaint());
jFrame.setVisible(true);
}
}
How to display special characters in PHP
One of the best ways to do this is, change Collation in my SQL database.
step 1: Go to the Mysql database
step 2: Select the Text-based Row you want to get displayed (Eg., post or comments)
step 3: edit the row and select collation as below.
utf8mb4_unicode_ci
Make sure to change the collation of text rows whichever you want to display the special characters.
Sometimes htmlspecialchars_decode() or any other entity() doesn't convert your special chars to normal. So, the above method will definitely help.
Heap vs Binary Search Tree (BST)
When to use a heap and when to use a BST
Heap is better at findMin/findMax (O(1)
), while BST is good at all finds (O(logN)
). Insert is O(logN)
for both structures. If you only care about findMin/findMax (e.g. priority-related), go with heap. If you want everything sorted, go with BST.
First few slides from here explain things very clearly.
SQL - How to select a row having a column with max value
The simplest answer would be
--Setup a test table called "t1"
create table t1
(date datetime,
value int)
-- Load the data.
-- Note: date format different than in the question
insert into t1
Select '5/18/2010 13:00',40
union all
Select '5/18/2010 14:00',20
union all
Select '5/18/2010 15:00',60
union all
Select '5/18/2010 16:00',30
union all
Select '5/18/2010 17:00',60
union all
Select '5/18/2010 18:00',25
-- find the row with the max qty and min date.
select *
from t1
where value =
(select max(value) from t1)
and date =
(select min(date)
from t1
where value = (select max(value) from t1))
I know you can do the "TOP 1" answer, but usually your solution gets just complicated enough that you can't use that for some reason.
Catch checked change event of a checkbox
In my experience, I've had to leverage the event's currentTarget:
$("#dingus").click( function (event) {
if ($(event.currentTarget).is(':checked')) {
//checkbox is checked
}
});
How to ignore PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException?
I have used the below code to override the SSL checking in my project and it worked for me.
package com.beingjavaguys.testftp;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;
import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.security.cert.X509Certificate;
/**
* Fix for Exception in thread "main" javax.net.ssl.SSLHandshakeException:
* sun.security.validator.ValidatorException: PKIX path building failed:
* sun.security.provider.certpath.SunCertPathBuilderException: unable to find
* valid certification path to requested target
*/
public class ConnectToHttpsUrl {
public static void main(String[] args) throws Exception {
/* Start of Fix */
TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {
public java.security.cert.X509Certificate[] getAcceptedIssuers() { return null; }
public void checkClientTrusted(X509Certificate[] certs, String authType) { }
public void checkServerTrusted(X509Certificate[] certs, String authType) { }
} };
SSLContext sc = SSLContext.getInstance("SSL");
sc.init(null, trustAllCerts, new java.security.SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
// Create all-trusting host name verifier
HostnameVerifier allHostsValid = new HostnameVerifier() {
public boolean verify(String hostname, SSLSession session) { return true; }
};
// Install the all-trusting host verifier
HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
/* End of the fix*/
URL url = new URL("https://nameofthesecuredurl.com");
URLConnection con = url.openConnection();
Reader reader = new InputStreamReader(con.getInputStream());
while (true) {
int ch = reader.read();
if (ch == -1)
break;
System.out.print((char) ch);
}
}
}
Java SimpleDateFormat for time zone with a colon separator?
Thanks acdcjunior for your solution. Here's a little optimized version for formatting and parsing :
public static final SimpleDateFormat XML_SDF = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.FRANCE)
{
private static final long serialVersionUID = -8275126788734707527L;
public StringBuffer format(Date date, StringBuffer toAppendTo, java.text.FieldPosition pos)
{
final StringBuffer buf = super.format(date, toAppendTo, pos);
buf.insert(buf.length() - 2, ':');
return buf;
};
public Date parse(String source) throws java.text.ParseException {
final int split = source.length() - 2;
return super.parse(source.substring(0, split - 1) + source.substring(split)); // replace ":" du TimeZone
};
};
Does java.util.List.isEmpty() check if the list itself is null?
Yes, it will throw an Exception. maybe you are used to PHP code, where empty($element)
does also check for isset($element)
? In Java this is not the case.
You can memorize that easily because the method is directly called on the list (the method belongs to the list). So if there is no list, then there is no method. And Java will complain that there is no list to call this method on.
SMTP error 554
554 is commonly used by dns blacklists when shooing away blacklisted servers. I'm assuming
Mon 2008-10-20 16:11:36: * relays.ordb.org - failed
in the log you included is to blame.
What does it mean to have an index to scalar variable error? python
IndexError: invalid index to scalar variable
happens when you try to index a numpy
scalar such as numpy.int64
or numpy.float64
. It is very similar to TypeError: 'int' object has no attribute '__getitem__'
when you try to index an int
.
>>> a = np.int64(5)
>>> type(a)
<type 'numpy.int64'>
>>> a[3]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
IndexError: invalid index to scalar variable.
>>> a = 5
>>> type(a)
<type 'int'>
>>> a[3]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: 'int' object has no attribute '__getitem__'
Regex to check whether a string contains only numbers
Simple Regex javascript
var cnpj = "12.32.432/1-22";
var rCnpj = cnpj.replace(/\D/gm,"");
console.log(cnpj);
*Result:
1232432122
Checks for only numbers:
if(rCnpj === cnpj){
return true;
}
Simple example
if("12.32.432/1-22".replace(/\D/gm,"").length > 0){
console.log("Ok.");
}
Adding POST parameters before submit
you can do this without jQuery:
var form=document.getElementById('form-id');//retrieve the form as a DOM element
var input = document.createElement('input');//prepare a new input DOM element
input.setAttribute('name', inputName);//set the param name
input.setAttribute('value', inputValue);//set the value
input.setAttribute('type', inputType)//set the type, like "hidden" or other
form.appendChild(input);//append the input to the form
form.submit();//send with added input
How to import local packages without gopath
Go dependency management summary:
vgo
if your go version is: x >= go 1.11
dep
or vendor
if your go version is: go 1.6 >= x < go 1.11
- Manually if your go version is:
x < go 1.6
Edit 3: Go 1.11 has a feature vgo
which will replace dep
.
To use vgo
, see Modules documentation. TLDR below:
export GO111MODULE=on
go mod init
go mod vendor # if you have vendor/ folder, will automatically integrate
go build
This method creates a file called go.mod
in your projects directory. You can then build your project with go build
. If GO111MODULE=auto
is set, then your project cannot be in $GOPATH
.
Edit 2: The vendoring method is still valid and works without issue. vendor
is largely a manual process, because of this dep
and vgo
were created.
Edit 1: While my old way works it's not longer the "correct" way to do it. You should be using vendor capabilities, vgo
, or dep
(for now) that are enabled by default in Go 1.6; see. You basically add your "external" or "dependent" packages within a vendor
directory; upon compilation the compiler will use these packages first.
Found. I was able import local package with GOPATH
by creating a subfolder of package1
and then importing with import "./package1"
in binary1.go
and binary2.go
scripts like this :
binary1.go
...
import (
"./package1"
)
...
So my current directory structure looks like this:
myproject/
+-- binary1.go
+-- binary2.go
+-- package1/
¦ +-- package1.go
+-- package2.go
I should also note that relative paths (at least in go 1.5) also work; for example:
import "../packageX"
Local file access with JavaScript
FSO.js wraps the new HTML5 FileSystem API that's being standardized by the W3C and provides an extremely easy way to read from, write to, or traverse a local sandboxed file system. It's asynchronous, so file I/O will not interfere with user experience. :)
Add to Array jQuery
You are right. This has nothing to do with jQuery though.
var myArray = [];
myArray.push("foo");
// myArray now contains "foo" at index 0.
Boolean.parseBoolean("1") = false...?
Returns true if comes 'y', '1', 'true', 'on'or whatever you add in similar way
boolean getValue(String value) {
return ("Y".equals(value.toUpperCase())
|| "1".equals(value.toUpperCase())
|| "TRUE".equals(value.toUpperCase())
|| "ON".equals(value.toUpperCase())
);
}
Disable dragging an image from an HTML page
simplest cross browser solution is
<img draggable="false" ondragstart="return false;" src="..." />
problem with
img {
-moz-user-select: none;
-webkit-user-select: none;
-ms-user-select: none;
user-select: none;
-webkit-user-drag: none;
user-drag: none;
-webkit-touch-callout: none;
}
is that it is not working in firefox
Javascript parse float is ignoring the decimals after my comma
In my case, I already had a period(.)
and also a comma(,)
, so what worked for me was to replace
the comma(,)
with an empty string like below:
parseFloat('3,000.78'.replace(',', ''))
This is assuming that the amount from the existing database is 3,000.78. The results are: 3000.78
without the initial comma(,)
.
How do I send an HTML Form in an Email .. not just MAILTO
> 2020 Answer = The Easy Way using Google Apps Script (5 Mins)
We had a similar challenge to solve yesterday, and we solved it using a Google Apps Script!
Send Email From an HTML Form Without a Backend (Server) via Google!
The solution takes 5 mins to implement and I've documented with step-by-step instructions: https://github.com/nelsonic/html-form-send-email-via-google-script-without-server
Brief Overview
A. Using the sample script, deploy a Google App Script
Deploy the sample script as a Google Spreadsheet APP Script:
google-script-just-email.js
remember to set the TO_ADDRESS
in the script to where ever you want the emails to be sent.
and copy the APP URL so you can use it in the next step when you publish the script.
B. Create your HTML Form and Set the action
to the App URL
Using the sample html
file:
index.html
create a basic form.
remember to paste your APP URL into the form action
in the HTML form.
C. Test the HTML Form in your Browser
Open the HTML Form in your Browser, Input some data & submit it!
Submit the form. You should see a confirmation that it was sent:
Open the inbox for the email address you set (above)
Done.
Everything about this is customisable, you can easily
style/theme the form with your favourite CSS Library
and Store the submitted data in a Google Spreadsheet
for quick analysis.
The complete instructions are available on GitHub:
https://github.com/nelsonic/html-form-send-email-via-google-script-without-server
Pick any kind of file via an Intent in Android
this work for me on galaxy note
its show
contacts,
file managers installed on device,
gallery,
music player
private void openFile(Int CODE) {
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.setType("*/*");
startActivityForResult(intent, CODE);
}
here get path in onActivityResult
of activity.
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
String Fpath = data.getDataString();
// do somthing...
super.onActivityResult(requestCode, resultCode, data);
}
How to fix a Div to top of page with CSS only
You can also use flexbox, but you'd have to add a parent div that covers div#top
and div#term-defs
. So the HTML looks like this:
_x000D_
_x000D_
#content {_x000D_
width: 100%;_x000D_
height: 100%;_x000D_
display: flex;_x000D_
flex-direction: column;_x000D_
}_x000D_
_x000D_
#term-defs {_x000D_
flex-grow: 1;_x000D_
overflow: auto;_x000D_
}
_x000D_
<body>_x000D_
<div id="content">_x000D_
<div id="top">_x000D_
<a href="#A">A</a> |_x000D_
<a href="#B">B</a> |_x000D_
<a href="#Z">Z</a>_x000D_
</div>_x000D_
_x000D_
<div id="term-defs">_x000D_
<dl>_x000D_
<span id="A"></span>_x000D_
<dt>foo</dt>_x000D_
<dd>This is the sound made by a fool</dd>_x000D_
<!-- and so on ... -->_x000D_
</dl>_x000D_
</div>_x000D_
</div>_x000D_
</body>
_x000D_
_x000D_
_x000D_
flex-grow
ensures that the div's size is equal to the remaining size.
You could do the same without flexbox, but it would be more complicated to work out the height of #term-defs
(you'd have to know the height of #top
and use calc(100% - 999px)
or set the height of #term-defs
directly).
With flexbox dynamic sizes of the divs are possible.
One difference is that the scrollbar only appears on the term-defs div
.
How do I get the App version and build number using Swift?
Updated for Swift 3.0
The NS
-prefixes are now gone in Swift 3.0 and several properties/methods have changed names to be more Swifty. Here's what this looks like now:
extension Bundle {
var releaseVersionNumber: String? {
return infoDictionary?["CFBundleShortVersionString"] as? String
}
var buildVersionNumber: String? {
return infoDictionary?["CFBundleVersion"] as? String
}
}
Bundle.main.releaseVersionNumber
Bundle.main.buildVersionNumber
Old Updated Answer
I've been working with Frameworks a lot since my original answer, so I
wanted to update my solution to something that is both simpler and
much more useful in a multi-bundle environment:
extension NSBundle {
var releaseVersionNumber: String? {
return self.infoDictionary?["CFBundleShortVersionString"] as? String
}
var buildVersionNumber: String? {
return self.infoDictionary?["CFBundleVersion"] as? String
}
}
Now this extension will be useful in apps to identify both the main
bundle and any other included bundles (such as a shared framework for
extension programming or third frameworks like AFNetworking), like so:
NSBundle.mainBundle().releaseVersionNumber
NSBundle.mainBundle().buildVersionNumber
// or...
NSBundle(URL: someURL)?.releaseVersionNumber
NSBundle(URL: someURL)?.buildVersionNumber
Original Answer
I wanted to improve on some of the answers already posted. I wrote a
class extension that can be added to your tool chain to handle this in
a more logical fashion.
extension NSBundle {
class var applicationVersionNumber: String {
if let version = NSBundle.mainBundle().infoDictionary?["CFBundleShortVersionString"]
as? String {
return version
}
return "Version Number Not Available"
}
class var applicationBuildNumber: String {
if let build = NSBundle.mainBundle().infoDictionary?["CFBundleVersion"] as? String {
return build
}
return "Build Number Not Available"
}
}
So now you can access this easily by:
let versionNumber = NSBundle.applicationVersionNumber
How to work offline with TFS
Depending on which tool windows you have open, VS may or may not try to hit the team server automatically when it starts up.
For best results try this:
- Close all instances of visual studio
- Open an empty visual studio (no project/solution)
- See which windows are opened by default, if source control explorer or team explorer or any other windows that use team are opened (and activated) by default, close them or switch them to a background tab.
- Close visual studio
You should notice now that you can start visual studio without it trying to hit the TFS server.
I know its just an aside to your problem, but I hope you find this helpful!
Generate GUID in MySQL for existing Data?
// UID Format: 30B9BE365FF011EA8F4C125FC56F0F50
UPDATE `events` SET `evt_uid` = (SELECT UPPER(REPLACE(@i:=UUID(),'-','')));
// UID Format: c915ec5a-5ff0-11ea-8f4c-125fc56f0f50
UPDATE `events` SET `evt_uid` = (SELECT UUID());
// UID Format: C915EC5a-5FF0-11EA-8F4C-125FC56F0F50
UPDATE `events` SET `evt_uid` = (SELECT UPPER(@i:=UUID()));
Can I dynamically add HTML within a div tag from C# on load event?
You want to put code in the master page code behind that inserts HTML into the contents of a page that is using that master page?
I would not search for the control via FindControl as this is a fragile solution that could easily be broken if the name of the control changed.
Your best bet is to declare an event in the master page that any child page could handle. The event could pass the HTML as an EventArg.
How to press back button in android programmatically?
onBackPressed()
is supported since: API Level 5
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
onBackPressed();
}
}
@Override
public void onBackPressed() {
//this is only needed if you have specific things
//that you want to do when the user presses the back button.
/* your specific things...*/
super.onBackPressed();
}
Editable 'Select' element
Similar to answer above but without the absolute positioning:
<select style="width: 200px; float: left;" onchange="this.nextElementSibling.value=this.value">
<option></option>
<option>1</option>
<option>2</option>
<option>3</option>
</select>
<input style="width: 185px; margin-left: -199px; margin-top: 1px; border: none; float: left;"/>
So create a input box and put it over the top of the combobox
How do I fill arrays in Java?
In Java-8 you can use IntStream
to produce a stream of numbers that you want to repeat, and then convert it to array. This approach produces an expression suitable for use in an initializer:
int[] data = IntStream.generate(() -> value).limit(size).toArray();
Above, size
and value
are expressions that produce the number of items that you want tot repeat and the value being repeated.
Demo.
Paging with Oracle
In the interest of completeness, for people looking for a more modern solution, in Oracle 12c there are some new features including better paging and top handling.
Paging
The paging looks like this:
SELECT *
FROM user
ORDER BY first_name
OFFSET 5 ROWS FETCH NEXT 10 ROWS ONLY;
Top N Records
Getting the top records looks like this:
SELECT *
FROM user
ORDER BY first_name
FETCH FIRST 5 ROWS ONLY
Notice how both the above query examples have ORDER BY
clauses. The new commands respect these and are run on the sorted data.
I couldn't find a good Oracle reference page for FETCH
or OFFSET
but this page has a great overview of these new features.
Performance
As @wweicker points out in the comments below, performance is an issue with the new syntax in 12c. I didn't have a copy of 18c to test if Oracle has since improved it.
Interestingly enough, my actual results were returned slightly quicker the first time I ran the queries on my table (113 million+ rows) for the new method:
- New method: 0.013 seconds.
- Old method: 0.107 seconds.
However, as @wweicker mentioned, the explain plan looks much worse for the new method:
- New method cost: 300,110
- Old method cost: 30
The new syntax caused a full scan of the index on my column, which was the entire cost. Chances are, things get much worse when limiting on unindexed data.
Let's have a look when including a single unindexed column on the previous dataset:
- New method time/cost: 189.55 seconds/998,908
- Old method time/cost: 1.973 seconds/256
Summary: use with caution until Oracle improves this handling. If you have an index to work with, perhaps you can get away with using the new method.
Hopefully I'll have a copy of 18c to play with soon and can update
Decode UTF-8 with Javascript
Here is a solution handling all Unicode code points include upper (4 byte) values and supported by all modern browsers (IE and others > 5.5). It uses decodeURIComponent(), but NOT the deprecated escape/unescape functions:
function utf8_to_str(a) {
for(var i=0, s=''; i<a.length; i++) {
var h = a[i].toString(16)
if(h.length < 2) h = '0' + h
s += '%' + h
}
return decodeURIComponent(s)
}
Tested and available on GitHub
To create UTF-8 from a string:
function utf8_from_str(s) {
for(var i=0, enc = encodeURIComponent(s), a = []; i < enc.length;) {
if(enc[i] === '%') {
a.push(parseInt(enc.substr(i+1, 2), 16))
i += 3
} else {
a.push(enc.charCodeAt(i++))
}
}
return a
}
Tested and available on GitHub
How can I lock a file using java (if possible)
Use this for unix if you are transferring using winscp or ftp:
public static void isFileReady(File entry) throws Exception {
long realFileSize = entry.length();
long currentFileSize = 0;
do {
try (FileInputStream fis = new FileInputStream(entry);) {
currentFileSize = 0;
while (fis.available() > 0) {
byte[] b = new byte[1024];
int nResult = fis.read(b);
currentFileSize += nResult;
if (nResult == -1)
break;
}
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("currentFileSize=" + currentFileSize + ", realFileSize=" + realFileSize);
} while (currentFileSize != realFileSize);
}
Python date string to date object
you have a date string like this, "24052010" and you want date object for this,
from datetime import datetime
cus_date = datetime.strptime("24052010", "%d%m%Y").date()
this cus_date will give you date object.
you can retrieve date string from your date object using this,
cus_date.strftime("%d%m%Y")
How do you increase the max number of concurrent connections in Apache?
Here's a detailed explanation about the calculation of MaxClients and MaxRequestsPerChild
http://web.archive.org/web/20160415001028/http://www.genericarticles.com/mediawiki/index.php?title=How_to_optimize_apache_web_server_for_maximum_concurrent_connections_or_increase_max_clients_in_apache
ServerLimit 16
StartServers 2
MaxClients 200
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
First of all, whenever an apache is started, it will start 2 child processes which is determined by StartServers
parameter. Then each process will start 25 threads determined by ThreadsPerChild
parameter so this means 2 process can service only 50 concurrent connections/clients i.e. 25x2=50. Now if more concurrent users comes, then another child process will start, that can service another 25 users. But how many child processes can be started is controlled by ServerLimit
parameter, this means that in the configuration above, I can have 16 child processes in total, with each child process can handle 25 thread, in total handling 16x25=400 concurrent users. But if number defined in MaxClients
is less which is 200 here, then this means that after 8 child processes, no extra process will start since we have defined an upper cap of MaxClients
. This also means that if I set MaxClients
to 1000, after 16 child processes and 400 connections, no extra process will start and we cannot service more than 400 concurrent clients even if we have increase the MaxClient
parameter. In this case, we need to also increase ServerLimit
to 1000/25 i.e. MaxClients/ThreadsPerChild=40
So this is the optmized configuration to server 1000 clients
<IfModule mpm_worker_module>
ServerLimit 40
StartServers 2
MaxClients 1000
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 0
</IfModule>
How do I scroll the UIScrollView when the keyboard appears?
Use following extension if you don't want to calculate too much:
func scrollSubviewToBeVisible(subview: UIView, animated: Bool) {
let visibleFrame = UIEdgeInsetsInsetRect(self.bounds, self.contentInset)
let subviewFrame = subview.convertRect(subview.bounds, toView: self)
if (!CGRectContainsRect(visibleFrame, subviewFrame)) {
self.scrollRectToVisible(subviewFrame, animated: animated)
}
}
And maybe you want keep your UITextField always visible:
func textViewDidChange(textView: UITextView) {
self.scrollView?.scrollSubviewToBeVisible(textView, animated: false)
}
Add column to SQL Server
Add new column to Table with default value.
ALTER TABLE NAME_OF_TABLE
ADD COLUMN_NAME datatype
DEFAULT DEFAULT_VALUE
get current url in twig template?
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) %}
The app
global view variable contains all sorts of useful shortcuts, such as app.session
and app.security.token.user
, that reference the services you might use in a controller.
Possible to make labels appear when hovering over a point in matplotlib?
From http://matplotlib.sourceforge.net/examples/event_handling/pick_event_demo.html :
from matplotlib.pyplot import figure, show
import numpy as npy
from numpy.random import rand
if 1: # picking on a scatter plot (matplotlib.collections.RegularPolyCollection)
x, y, c, s = rand(4, 100)
def onpick3(event):
ind = event.ind
print('onpick3 scatter:', ind, npy.take(x, ind), npy.take(y, ind))
fig = figure()
ax1 = fig.add_subplot(111)
col = ax1.scatter(x, y, 100*s, c, picker=True)
#fig.savefig('pscoll.eps')
fig.canvas.mpl_connect('pick_event', onpick3)
show()
comma separated string of selected values in mysql
Try this
SELECT CONCAT('"',GROUP_CONCAT(id),'"') FROM table_level
where parent_id=4 group by parent_id;
Result will be
"5,6,9,10,12,14,15,17,18,779"
How do I extract the contents of an rpm?
$ mkdir packagecontents; cd packagecontents
$ rpm2cpio ../foo.rpm | cpio -idmv
$ find .
For Reference: the cpio arguments are
-i = extract
-d = make directories
-m = preserve modification time
-v = verbose
I found the answer over here: lontar's answer
What is the easiest way to encrypt a password when I save it to the registry?
If you want to be able to decrypt the password, I think the easiest way would be to use DPAPI (user store mode) to encrypt/decrypt. This way you don't have to fiddle with encryption keys, store them somewhere or hard-code them in your code - in both cases somebody can discover them by looking into registry, user settings or using Reflector.
Otherwise use hashes SHA1 or MD5 like others have said here.
Can I call an overloaded constructor from another constructor of the same class in C#?
In C# it is not possible to call another constructor from inside the method body.
You can call a base constructor this way: foo(args):base() as pointed out yourself.
You can also call another constructor in the same class: foo(args):this().
When you want to do something before calling a base constructor, it seems the construction of the base is class is dependant of some external things. If so, you should through arguments of the base constructor, not by setting properties of the base class or something like that
How to view the roles and permissions granted to any database user in Azure SQL server instance?
Building on @tmullaney 's answer, you can also left join in the sys.objects view to get insight when explicit permissions have been granted on objects. Make sure to use the LEFT join:
SELECT DISTINCT pr.principal_id, pr.name AS [UserName], pr.type_desc AS [User_or_Role], pr.authentication_type_desc AS [Auth_Type], pe.state_desc,
pe.permission_name, pe.class_desc, o.[name] AS 'Object'
FROM sys.database_principals AS pr
JOIN sys.database_permissions AS pe ON pe.grantee_principal_id = pr.principal_id
LEFT JOIN sys.objects AS o on (o.object_id = pe.major_id)
How to revert multiple git commits?
First be sure that your working copy is not modified. Then:
git diff --binary HEAD commit_sha_you_want_to_revert_to | git apply
and then just commit. Don't forget to document what's the reason for revert.
react native get TextInput value
This piece of code worked for me. What I was missing was I was not passing 'this' in button action:
onPress={this._handlePress.bind(this)}>
--------------
_handlePress(event) {
console.log('Pressed!');
var username = this.state.username;
var password = this.state.password;
console.log(username);
console.log(password);
}
render() {
return (
<View style={styles.container}>
<TextInput
ref="usr"
style={{height: 40, borderColor: 'gray', borderWidth: 1 , marginTop: 10 , padding : 10 , marginLeft : 5 , marginRight : 5 }}
placeHolder= "Enter username "
placeholderTextColor = '#a52a2a'
returnKeyType = {"next"}
autoFocus = {true}
autoCapitalize = "none"
autoCorrect = {false}
clearButtonMode = 'while-editing'
onChangeText={(text) => {
this.setState({username:text});
}}
onSubmitEditing={(event) => {
this.refs.psw.focus();
}}
/>
<TextInput
ref="psw"
style={{height: 40, borderColor: 'gray', borderWidth: 1 , marginTop: 10,marginLeft : 5 , marginRight : 5}}
placeholder= "Enter password"
placeholderTextColor = '#a52a2a'
autoCapitalize = "none"
autoCorrect = {false}
returnKeyType = {'done'}
secureTextEntry = {true}
clearButtonMode = 'while-editing'
onChangeText={(text) => {
this.setState({password:text});
}}
/>
<Button
style={{borderWidth: 1, borderColor: 'blue'}}
onPress={this._handlePress.bind(this)}>
Login
</Button>
</View>
);``
}
}
Convert multidimensional array into single array
Following this pattern
$input = array(10, 20, array(30, 40), array('key1' => '50', 'key2'=>array(60), 70));
Call the function :
echo "<pre>";print_r(flatten_array($input, $output=null));
Function Declaration :
function flatten_array($input, $output=null) {
if($input == null) return null;
if($output == null) $output = array();
foreach($input as $value) {
if(is_array($value)) {
$output = flatten_array($value, $output);
} else {
array_push($output, $value);
}
}
return $output;
}
Python strip() multiple characters?
strip
only strips characters from the very front and back of the string.
To delete a list of characters, you could use the string's translate
method:
import string
name = "Barack (of Washington)"
table = string.maketrans( '', '', )
print name.translate(table,"(){}<>")
# Barack of Washington