Not able to change TextField Border Color
The code in which you change the color of the primaryColor andprimaryColorDark does not change the color inicial of the border, only after tap the color stay black
The attribute that must be changed is hintColor
BorderSide should not be used for this, you need to change Theme.
To make the red color default to put the theme in MaterialApp(theme: ...) and to change the theme of a specific widget, such as changing the default red color to the yellow color of the widget, surrounds the widget with:
new Theme(
data: new ThemeData(
hintColor: Colors.yellow
),
child: ...
)
Below is the code and gif:
Note that if we define the primaryColor color as black, by tapping the widget it is selected with the color black
But to change the label and text inside the widget, we need to set the theme to InputDecorationTheme
The widget that starts with the yellow color has its own theme and the widget that starts with the red color has the default theme defined with the function buildTheme()
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
ThemeData buildTheme() {
final ThemeData base = ThemeData();
return base.copyWith(
hintColor: Colors.red,
primaryColor: Colors.black,
inputDecorationTheme: InputDecorationTheme(
hintStyle: TextStyle(
color: Colors.blue,
),
labelStyle: TextStyle(
color: Colors.green,
),
),
);
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
theme: buildTheme(),
home: new HomePage(),
);
}
}
class HomePage extends StatefulWidget {
@override
_HomePageState createState() => new _HomePageState();
}
class _HomePageState extends State<HomePage> {
String xp = '0';
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(),
body: new Container(
padding: new EdgeInsets.only(top: 16.0),
child: new ListView(
children: <Widget>[
new InkWell(
onTap: () {},
child: new Theme(
data: new ThemeData(
hintColor: Colors.yellow
),
child: new TextField(
decoration: new InputDecoration(
border: new OutlineInputBorder(),
hintText: 'Tell us about yourself',
helperText: 'Keep it short, this is just a demo.',
labelText: 'Life story',
prefixIcon: const Icon(Icons.person, color: Colors.green,),
prefixText: ' ',
suffixText: 'USD',
suffixStyle: const TextStyle(color: Colors.green)),
)
)
),
new InkWell(
onTap: () {},
child: new TextField(
decoration: new InputDecoration(
border: new OutlineInputBorder(
borderSide: new BorderSide(color: Colors.teal)
),
hintText: 'Tell us about yourself',
helperText: 'Keep it short, this is just a demo.',
labelText: 'Life story',
prefixIcon: const Icon(Icons.person, color: Colors.green,),
prefixText: ' ',
suffixText: 'USD',
suffixStyle: const TextStyle(color: Colors.green)),
)
)
],
),
)
);
}
}
How to add a recyclerView inside another recyclerView
you can use LayoutInflater to inflate your dynamic data as a layout file.
UPDATE : first create a LinearLayout inside your CardView's layout and assign an ID for it.
after that create a layout file that you want to inflate. at last in your onBindViewHolder method in your "RAdaper" class. write these codes :
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = mInflater.inflate(R.layout.my_list_custom_row, parent, false);
after that you can initialize data and ClickListeners with your RAdapter Data. hope it helps.
New xampp security concept: Access Forbidden Error 403 - Windows 7 - phpMyAdmin
All you have to do is to edit the httpd-xampp.conf
from Require local to Require all granted in the LocationMatch tag.
That's it!
CS0120: An object reference is required for the nonstatic field, method, or property 'foo'
I actually got this error because I was checking InnerHtml for some content that was generated dynamically - i.e. a control that is runat=server.
To solve this I had to remove the "static" keyword on my method, and it ran fine.
How to draw a graph in PHP?
By far the easiest solution is to just use the Google Chart API http://code.google.com/apis/chart/
You can make bar graphs, pie charts, use 3D, and it's as easy as building a url with some parameters. See the simple example below.
Android: how to handle button click
To make things easier asp Question 2 stated, you can make use of lambda method like this to save variable memory and to avoid navigating up and down in your view class
//method 1
findViewById(R.id.buttonSend).setOnClickListener(v -> {
// handle click
});
but if you wish to apply click event to your button at once in a method.
you can make use of Question 3 by @D. Tran answer. But do not forget to implement your view class with View.OnClickListener.
In other to use Question #3 properly
How to convert JSON to a Ruby hash
Assuming you have a JSON hash hanging around somewhere, to automatically convert it into something like WarHog's version, wrap your JSON hash contents in %q{hsh} tags.
This seems to automatically add all the necessary escaped text like in WarHog's answer.
Selenium WebDriver: I want to overwrite value in field instead of appending to it with sendKeys using Java
Had issues using most of the mentioned methods since textfield had not accepted keyboard input, and the mouse solution seem not complete.
This worked for to simulate a click in the field, selecting the content and replacing it with new.
Actions actionList = new Actions(driver);
actionList.clickAndHold(WebElement).sendKeys(newTextFieldString).
release().build().perform();
How to remove indentation from an unordered list item?
I have the same problem with a footer I'm trying to divide up. I found that this worked for me by trying few of above suggestions combined:
footer div ul {
list-style-position: inside;
padding-left: 0;
}
This seems to keep it to the left under my h1 and the bullet points inside the div rather than outside to the left.
How to get the real path of Java application at runtime?
It isn't clear what you're asking for. I don't know what 'with respect to the web application we are using' means if getServletContext().getRealPath() isn't the answer, but:
- The current user's current working directory is given by
System.getProperty("user.dir") - The current user's home directory is given by
System.getProperty("user.home") - The location of the JAR file from which the current class was loaded is given by
this.getClass().getProtectionDomain().getCodeSource().getLocation().
Objective-C - Remove last character from string
In your controller class, create an action method you will hook the button up to in Interface Builder. Inside that method you can trim your string like this:
if ([string length] > 0) {
string = [string substringToIndex:[string length] - 1];
} else {
//no characters to delete... attempting to do so will result in a crash
}
If you want a fancy way of doing this in just one line of code you could write it as:
string = [string substringToIndex:string.length-(string.length>0)];
*Explanation of fancy one-line code snippet:
If there is a character to delete (i.e. the length of the string is greater than 0)
(string.length>0) returns 1 thus making the code return:
string = [string substringToIndex:string.length-1];
If there is NOT a character to delete (i.e. the length of the string is NOT greater than 0)
(string.length>0) returns 0 thus making the code return:
string = [string substringToIndex:string.length-0];
Which prevents crashes.
How to make a class property?
I think you may be able to do this with the metaclass. Since the metaclass can be like a class for the class (if that makes sense). I know you can assign a __call__() method to the metaclass to override calling the class, MyClass(). I wonder if using the property decorator on the metaclass operates similarly. (I haven't tried this before, but now I'm curious...)
[update:]
Wow, it does work:
class MetaClass(type):
def getfoo(self):
return self._foo
foo = property(getfoo)
@property
def bar(self):
return self._bar
class MyClass(object):
__metaclass__ = MetaClass
_foo = 'abc'
_bar = 'def'
print MyClass.foo
print MyClass.bar
Note: This is in Python 2.7. Python 3+ uses a different technique to declare a metaclass. Use: class MyClass(metaclass=MetaClass):, remove __metaclass__, and the rest is the same.
SELECT list is not in GROUP BY clause and contains nonaggregated column .... incompatible with sql_mode=only_full_group_by
> sudo nano /etc/mysql/my.cnf
Enter below
[mysqld]
sql_mode = ""
Ctrl + O => Y = Ctrl + X
> sudo service mysql restart
MIT vs GPL license
IANAL but as I see it....
While you can combine GPL and MIT code, the GPL is tainting. Which means the package as a whole gets the limitations of the GPL. As that is more restrictive you can no longer use it in commercial (or rather closed source) software. Which also means if you have a MIT/BSD/ASL project you will not want to add dependencies to GPL code.
Adding a GPL dependency does not change the license of your code but it will limit what people can do with the artifact of your project. This is also why the ASF does not allow dependencies to GPL code for their projects.
"An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page..."
First, set customErrors = "Off" in the web.config and redeploy to get a more detailed error message that will help us diagnose the problem. You could also RDP into the instance and browse to the site from IIS locally to view the errors.
<system.web>
<customErrors mode="Off" />
First guess though - you have some references (most likely Azure SDK references) that are not set to Copy Local = true. So, all your dependencies are not getting deployed.
Get to the detailed error first and update your question.
UPDATE: A second option now available in VS2013 is Remote Debugging a Cloud Service or Virtual Machine.
How to rename a pane in tmux?
You can adjust the pane title by setting the pane border in the tmux.conf for example like this:
###############
# pane border #
###############
set -g pane-border-status bottom
#colors for pane borders
setw -g pane-border-style fg=green,bg=black
setw -g pane-active-border-style fg=colour118,bg=black
setw -g automatic-rename off
setw -g pane-border-format ' #{pane_index} #{pane_title} : #{pane_current_path} '
# active pane normal, other shaded out?
setw -g window-style fg=colour28,bg=colour16
setw -g window-active-style fg=colour46,bg=colour16
Where pane_index, pane_title and pane_current_path are variables provided by tmux itself.
After reloading the config or starting a new tmux session, you can then set the title of the current pane like this:
tmux select-pane -T "fancy pane title";
#or
tmux select-pane -t paneIndexInteger -T "fancy pane title";
If all panes have some processes running, so you can't use the command line, you can also type the commands after pressing the prefix bind (C-b by default) and a colon (:) without having "tmux" in the front of the command:
select-pane -T "fancy pane title"
#or:
select-pane -t paneIndexInteger -T "fancy pane title"
What is IllegalStateException?
package com.concepttimes.java;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class IllegalStateExceptionDemo {
public static void main(String[] args) {
// TODO Auto-generated method stub
List al = new ArrayList();
al.add("Sachin");
al.add("Rahul");
al.add("saurav");
Iterator itr = al.iterator();
while (itr.hasNext()) {
itr.remove();
}
}
}
IllegalStateException signals that method has been invoked at the wrong time. In this below example, we can see that. remove() method is called at the same time element is being used in while loop.
Please refer to below link for more details. http://www.elitmuszone.com/elitmus/illegalstateexception-in-java/
converting drawable resource image into bitmap
In res/drawable folder,
1. Create a new Drawable Resources.
2. Input file name.
A new file will be created inside the res/drawable folder.
Replace this code inside the newly created file and replace ic_action_back with your drawable file name.
<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
android:src="@drawable/ic_action_back"
android:tint="@color/color_primary_text" />
Now, you can use it with Resource ID, R.id.filename.
Converting a pointer into an integer
#include <stdint.h>- Use
uintptr_tstandard type defined in the included standard header file.
How to make <label> and <input> appear on the same line on an HTML form?
I've done this several different ways but the only way I've found that keeps the labels and corresponding text/input data on the same line and always wraps perfectly to the width of the parent is to use display:inline table.
CSS
.container {
display: inline-table;
padding-right: 14px;
margin-top:5px;
margin-bottom:5px;
}
.fieldName {
display: table-cell;
vertical-align: middle;
padding-right: 4px;
}
.data {
display: table-cell;
}
HTML
<div class='container'>
<div class='fieldName'>
<label>Student</label>
</div>
<div class='data'>
<input name="Student" />
</div>
</div>
<div class='container'>
<div class='fieldName'>
<label>Email</label>
</div>
<div class='data'>
<input name="Email" />
</div>
</div>
max(length(field)) in mysql
In case you need both max and min from same table:
select * from (
(select city, length(city) as maxlen from station
order by maxlen desc limit 1)
union
(select city, length(city) as minlen from station
order by minlen,city limit 1))a;
oracle varchar to number
select to_number(exception_value) from exception where to_number(exception_value) = 105
How to make graphics with transparent background in R using ggplot2?
Just to improve YCR's answer:
1) I added black lines on x and y axis. Otherwise they are made transparent too.
2) I added a transparent theme to the legend key. Otherwise, you will get a fill there, which won't be very esthetic.
Finally, note that all those work only with pdf and png formats. jpeg fails to produce transparent graphs.
MyTheme_transparent <- theme(
panel.background = element_rect(fill = "transparent"), # bg of the panel
plot.background = element_rect(fill = "transparent", color = NA), # bg of the plot
panel.grid.major = element_blank(), # get rid of major grid
panel.grid.minor = element_blank(), # get rid of minor grid
legend.background = element_rect(fill = "transparent"), # get rid of legend bg
legend.box.background = element_rect(fill = "transparent"), # get rid of legend panel bg
legend.key = element_rect(fill = "transparent", colour = NA), # get rid of key legend fill, and of the surrounding
axis.line = element_line(colour = "black") # adding a black line for x and y axis
)
How to get the cookie value in asp.net website
FormsAuthentication.Decrypt takes the actual value of the cookie, not the name of it. You can get the cookie value like
HttpContext.Current.Request.Cookies[FormsAuthentication.FormsCookieName].Value;
and decrypt that.
Powershell script to locate specific file/file name?
From a powershell prompt, use the gci cmdlet (alias for Get-ChildItem) and -filter option:
gci -recurse -filter "hosts"
This will return an exact match to filename "hosts".
SteveMustafa points out with current versions of powershell you can use the -File switch to give the following to recursively search for only files named "hosts" (and not directories or other miscellaneous file-system entities):
gci -recurse -filter "hosts" -File
The commands may print many red error messages like "Access to the path 'C:\Windows\Prefetch' is denied.".
If you want to avoid the error messages then set the -ErrorAction to be silent.
gci -recurse -filter "hosts" -File -ErrorAction SilentlyContinue
An additional helper is that you can set the root to search from using -Path.
The resulting command to search explicitly search from, for example, the root of the C drive would be
gci -Recurse -Filter "hosts" -File -ErrorAction SilentlyContinue -Path "C:\"
Turn ON/OFF Camera LED/flash light in Samsung Galaxy Ace 2.2.1 & Galaxy Tab
I will soon released a new version of my app to support to galaxy ace.
You can download here: https://play.google.com/store/apps/details?id=droid.pr.coolflashlightfree
In order to solve your problem you should do this:
this._camera = Camera.open();
this._camera.startPreview();
this._camera.autoFocus(new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
}
});
Parameters params = this._camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_ON);
this._camera.setParameters(params);
params = this._camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_OFF);
this._camera.setParameters(params);
don't worry about FLASH_MODE_OFF because this will keep the light on, strange but it's true
to turn off the led just release the camera
jQuery hasAttr checking to see if there is an attribute on an element
I wrote a hasAttr() plugin for jquery that will do all of this very simply, exactly as the OP has requested. More information here
EDIT: My plugin was deleted in the great plugins.jquery.com database deletion disaster of 2010. You can look here for some info on adding it yourself, and why it hasn't been added.
Changing text of UIButton programmatically swift
Swift 3:
Set button title:
//for normal state:
my_btn.setTitle("Button Title", for: .normal)
// For highlighted state:
my_btn.setTitle("Button Title2", for: .highlighted)
How to use OAuth2RestTemplate?
In the answer from @mariubog (https://stackoverflow.com/a/27882337/1279002) I was using password grant types too as in the example but needed to set the client authentication scheme to form. Scopes were not supported by the endpoint for password and there was no need to set the grant type as the ResourceOwnerPasswordResourceDetails object sets this itself in the constructor.
...
public ResourceOwnerPasswordResourceDetails() {
setGrantType("password");
}
...
The key thing for me was the client_id and client_secret were not being added to the form object to post in the body if resource.setClientAuthenticationScheme(AuthenticationScheme.form); was not set.
See the switch in:
org.springframework.security.oauth2.client.token.auth.DefaultClientAuthenticationHandler.authenticateTokenRequest()
Finally, when connecting to Salesforce endpoint the password token needed to be appended to the password.
@EnableOAuth2Client
@Configuration
class MyConfig {
@Value("${security.oauth2.client.access-token-uri}")
private String tokenUrl;
@Value("${security.oauth2.client.client-id}")
private String clientId;
@Value("${security.oauth2.client.client-secret}")
private String clientSecret;
@Value("${security.oauth2.client.password-token}")
private String passwordToken;
@Value("${security.user.name}")
private String username;
@Value("${security.user.password}")
private String password;
@Bean
protected OAuth2ProtectedResourceDetails resource() {
ResourceOwnerPasswordResourceDetails resource = new ResourceOwnerPasswordResourceDetails();
resource.setAccessTokenUri(tokenUrl);
resource.setClientId(clientId);
resource.setClientSecret(clientSecret);
resource.setClientAuthenticationScheme(AuthenticationScheme.form);
resource.setUsername(username);
resource.setPassword(password + passwordToken);
return resource;
}
@Bean
public OAuth2RestOperations restTemplate() {
return new OAuth2RestTemplate(resource(), new DefaultOAuth2ClientContext(new DefaultAccessTokenRequest()));
}
}
@Service
@SuppressWarnings("unchecked")
class MyService {
@Autowired
private OAuth2RestOperations restTemplate;
public MyService() {
restTemplate.getAccessToken();
}
}
Push method in React Hooks (useState)?
The same way you do it with "normal" state in React class components.
example:
function App() {
const [state, setState] = useState([]);
return (
<div>
<p>You clicked {state.join(" and ")}</p>
//destructuring
<button onClick={() => setState([...state, "again"])}>Click me</button>
//old way
<button onClick={() => setState(state.concat("again"))}>Click me</button>
</div>
);
}
In c, in bool, true == 1 and false == 0?
You neglected to say which version of C you are concerned about. Let's assume it's this one:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf
As you can see by reading the specification, the standard definitions of true and false are 1 and 0, yes.
If your question is about a different version of C, or about non-standard definitions for true and false, then ask a more specific question.
How to change the DataTable Column Name?
Rename the Column by doing the following:
dataTable.Columns["ColumnName"].ColumnName = "newColumnName";
Enabling CORS in Cloud Functions for Firebase
For what it's worth I was having the same issue when passing app into onRequest. I realized the issue was a trailing slash on the request url for the firebase function. Express was looking for '/' but I didn't have the trailing slash on the function [project-id].cloudfunctions.net/[function-name]. The CORS error was a false negative. When I added the trailing slash, I got the response I was expecting.
git - remote add origin vs remote set-url origin
below is used to a add a new remote:
git remote add origin [email protected]:User/UserRepo.git
below is used to change the url of an existing remote repository:
git remote set-url origin [email protected]:User/UserRepo.git
below will push your code to the master branch of the remote repository defined with origin and -u let you point your current local branch to the remote master branch:
git push -u origin master
Python: count repeated elements in the list
You can do that using count:
my_dict = {i:MyList.count(i) for i in MyList}
>>> print my_dict #or print(my_dict) in python-3.x
{'a': 3, 'c': 3, 'b': 1}
Or using collections.Counter:
from collections import Counter
a = dict(Counter(MyList))
>>> print a #or print(a) in python-3.x
{'a': 3, 'c': 3, 'b': 1}
Set the space between Elements in Row Flutter
Just add "Container(width: 5, color: Colors.transparent)," between elements
new Container(
alignment: FractionalOffset.center,
child: new Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
new FlatButton(
child: new Text('Don\'t have an account?', style: new TextStyle(color: Color(0xFF2E3233))),
),
Container(width: 5, color: Colors.transparent),
new FlatButton(
child: new Text('Register.', style: new TextStyle(color: Color(0xFF84A2AF), fontWeight: FontWeight.bold),),
onPressed: moveToRegister,
)
],
),
),
Sorting a Data Table
Try this:
Dim dataView As New DataView(table)
dataView.Sort = " AutoID DESC, Name DESC"
Dim dataTable AS DataTable = dataView.ToTable()
Removing all script tags from html with JS Regular Expression
Regexes are beatable, but if you have a string version of HTML that you don't want to inject into a DOM, they may be the best approach. You may want to put it in a loop to handle something like:
<scr<script>Ha!</script>ipt> alert(document.cookie);</script>
Here's what I did, using the jquery regex from above:
var SCRIPT_REGEX = /<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi;
while (SCRIPT_REGEX.test(text)) {
text = text.replace(SCRIPT_REGEX, "");
}
Regex to split a CSV
The advantage of using JScript for classic ASP pages is that you can use one of the many, many libraries that have been written for JavaScript.
Like this one: https://github.com/gkindel/CSV-JS. Download it, include it in your ASP page, parse CSV with it.
<%@ language="javascript" %>
<script language="javascript" runat="server" src="scripts/csv.js"></script>
<script language="javascript" runat="server">
var text = '123,2.99,AMO024,Title,"Description, more info",,123987564',
rows = CSV.parse(line);
Response.Write(rows[0][4]);
</script>
Ansible: Store command's stdout in new variable?
In case than you want to store a complex command to compare text result, for example to compare the version of OS, maybe this can help you:
tasks:
- shell: echo $(cat /etc/issue | awk {'print $7'})
register: echo_content
- shell: echo "It works"
when: echo_content.stdout == "12"
register: out
- debug: var=out.stdout_lines
jquery - check length of input field?
If you mean that you want to enable the submit after the user has typed at least one character, then you need to attach a key event that will check it for you.
Something like:
$("#fbss").keypress(function() {
if($(this).val().length > 1) {
// Enable submit button
} else {
// Disable submit button
}
});
"unexpected token import" in Nodejs5 and babel?
Current method is to use:
npm install --save-dev babel-cli babel-preset-env
And then in in .babelrc
{
"presets": ["env"]
}
this install Babel support for latest version of js (es2015 and beyond) Check out babeljs
Do not forget to add babel-node to your scripts inside package.json use when running your js file as follows.
"scripts": {
"test": "mocha",
//Add this line to your scripts
"populate": "node_modules/babel-cli/bin/babel-node.js"
},
Now you can npm populate yourfile.js inside terminal.
If you are running windows and running error internal or external command not recognized, use node infront of the script as follow
node node_modules/babel-cli/bin/babel-node.js
Then npm run populate
Use async await with Array.map
I'd recommend using Promise.all as mentioned above, but if you really feel like avoiding that approach, you can do a for or any other loop:
const arr = [1,2,3,4,5];
let resultingArr = [];
for (let i in arr){
await callAsynchronousOperation(i);
resultingArr.push(i + 1)
}
Allow Google Chrome to use XMLHttpRequest to load a URL from a local file
On Ubuntu:
chromium-browser --disable-web-security
For more details/switches:
Writing an mp4 video using python opencv
just change the codec to "DIVX". This codec works with all formats.
fourcc = cv2.VideoWriter_fourcc(*'DIVX')
i hope this works for you!
Singletons vs. Application Context in Android?
From: Developer > reference - Application
There is normally no need to subclass Application. In most situation, static singletons can provide the same functionality in a more modular way. If your singleton needs a global context (for example to register broadcast receivers), the function to retrieve it can be given a Context which internally uses Context.getApplicationContext() when first constructing the singleton.
Receiving "fatal: Not a git repository" when attempting to remote add a Git repo
For that you need to enter one command that is missing from bitbucket commands
Please try git init.
How to check if a variable is equal to one string or another string?
if var == 'stringone' or var == 'stringtwo':
do_something()
or more pythonic,
if var in ['string one', 'string two']:
do_something()
Polynomial time and exponential time
polynomial time O(n)^k means Number of operations are proportional to power k of the size of input
exponential time O(k)^n means Number of operations are proportional to the exponent of the size of input
jQuery ajax request being block because Cross-Origin
Try with cURL request for cross-domain.
If you are working through third party APIs or getting data through CROSS-DOMAIN, it is always recommended to use cURL script (server side) which is more secure.
I always prefer cURL script.
Hash Table/Associative Array in VBA
Try using the Dictionary Object or the Collection Object.
http://visualbasic.ittoolbox.com/documents/dictionary-object-vs-collection-object-12196
Purge Kafka Topic
Temporarily update the retention time on the topic to one second:
kafka-topics.sh --zookeeper <zkhost>:2181 --alter --topic <topic name> --config retention.ms=1000
And in newer Kafka releases, you can also do it with kafka-configs --entity-type topics
kafka-configs.sh --zookeeper <zkhost>:2181 --entity-type topics --alter --entity-name <topic name> --add-config retention.ms=1000
then wait for the purge to take effect (about one minute). Once purged, restore the previous retention.ms value.
Finding element's position relative to the document
If you don't mind using jQuery, then you can use offset() function. Refer to documentation if you want to read up more about this function.
SQL Server GROUP BY datetime ignore hour minute and a select with a date and sum value
-- I like this as the data type and the format remains consistent with a date time data type
;with cte as(
select
cast(utcdate as date) UtcDay, DATEPART(hour, utcdate) UtcHour, count(*) as Counts
from dbo.mytable cd
where utcdate between '2014-01-14' and '2014-01-15'
group by
cast(utcdate as date), DATEPART(hour, utcdate)
)
select dateadd(hour, utchour, cast(utcday as datetime)) as UTCDateHour, Counts
from cte
Allow access permission to write in Program Files of Windows 7
If you have such a program just install it in C:\, not in Program Files. I had a lot of problems when I was installing Android SDK. My problem got solved by installing it in C:\.
sqlalchemy: how to join several tables by one query?
This function will produce required table as list of tuples.
def get_documents_by_user_email(email):
query = session.query(
User.email,
User.name,
Document.name,
DocumentsPermissions.readAllowed,
DocumentsPermissions.writeAllowed,
)
join_query = query.join(Document).join(DocumentsPermissions)
return join_query.filter(User.email == email).all()
user_docs = get_documents_by_user_email(email)
Terminating a script in PowerShell
Terminates this process and gives the underlying operating system the specified exit code.
https://msdn.microsoft.com/en-us/library/system.environment.exit%28v=vs.110%29.aspx
[Environment]::Exit(1)
This will allow you to exit with a specific exit code, that can be picked up from the caller.
Convert List to Pandas Dataframe Column
You can directly call the
method and pass your list as parameter.
l = ['Thanks You','Its fine no problem','Are you sure']
pd.DataFrame(l)
Output:
0
0 Thanks You
1 Its fine no problem
2 Are you sure
And if you have multiple lists and you want to make a dataframe out of it.You can do it as following:
import pandas as pd
names =["A","B","C","D"]
salary =[50000,90000,41000,62000]
age = [24,24,23,25]
data = pd.DataFrame([names,salary,age]) #Each list would be added as a row
data = data.transpose() #To Transpose and make each rows as columns
data.columns=['Names','Salary','Age'] #Rename the columns
data.head()
Output:
Names Salary Age
0 A 50000 24
1 B 90000 24
2 C 41000 23
3 D 62000 25
Apache Prefork vs Worker MPM
Prefork and worker are two type of MPM apache provides. Both have their merits and demerits.
By default mpm is prefork which is thread safe.
Prefork MPM uses multiple child processes with one thread each and each process handles one connection at a time.
Worker MPM uses multiple child processes with many threads each. Each thread handles one connection at a time.
For more details you can visit https://httpd.apache.org/docs/2.4/mpm.html and https://httpd.apache.org/docs/2.4/mod/prefork.html
Open page in new window without popup blocking
For the Submit button, add this code and then set your form target="newwin"
onclick=window.open("about:blank","newwin")
Run cron job only if it isn't already running
It's suprising that no one mentioned about run-one. I've solved my problem with this.
apt-get install run-one
then add run-one before your crontab script
*/20 * * * * * run-one python /script/to/run/awesome.py
Check out this askubuntu SE answer. You can find link to a detailed information there as well.
Printing PDFs from Windows Command Line
@ECHO off set "dir1=C:\TicketDownload"
FOR %%X in ("%dir1%*.pdf") DO ( "C:\Program Files (x86)\Adobe\Reader 9.0\Reader\AcroRd32.exe" /t "%%~dpnX.pdf" "Microsoft XPS Document Writer" )
FOR %%X in ("%dir1%*.pdf") DO (move "%%~dpnX.pdf" p/)
Try this..May be u have some other version of Reader so that is the problem..
How to parse a string into a nullable int
I feel my solution is a very clean and nice solution:
public static T? NullableParse<T>(string s) where T : struct
{
try
{
return (T)typeof(T).GetMethod("Parse", new[] {typeof(string)}).Invoke(null, new[] { s });
}
catch (Exception)
{
return null;
}
}
This is of course a generic solution which only require that the generics argument has a static method "Parse(string)". This works for numbers, boolean, DateTime, etc.
Import local function from a module housed in another directory with relative imports in Jupyter Notebook using Python 3
Came here searching for best practices in abstracting code to submodules when working in Notebooks. I'm not sure that there is a best practice. I have been proposing this.
A project hierarchy as such:
+-- ipynb
¦ +-- 20170609-Examine_Database_Requirements.ipynb
¦ +-- 20170609-Initial_Database_Connection.ipynb
+-- lib
+-- __init__.py
+-- postgres.py
And from 20170609-Initial_Database_Connection.ipynb:
In [1]: cd ..
In [2]: from lib.postgres import database_connection
This works because by default the Jupyter Notebook can parse the cd command. Note that this does not make use of Python Notebook magic. It simply works without prepending %bash.
Considering that 99 times out of a 100 I am working in Docker using one of the Project Jupyter Docker images, the following modification is idempotent
In [1]: cd /home/jovyan
In [2]: from lib.postgres import database_connection
How to calculate age in T-SQL with years, months, and days
declare @BirthDate datetime
declare @TotalYear int
declare @TotalMonths int
declare @TotalDays int
declare @TotalWeeks int
declare @TotalHours int
declare @TotalMinute int
declare @TotalSecond int
declare @CurrentDtTime datetime
set @BirthDate='1998/01/05 05:04:00' -- Set Your date here
set @TotalYear= FLOOR(DATEDIFF(DAY, @BirthDate, GETDATE()) / 365.25)
set @TotalMonths= FLOOR(DATEDIFF(DAY,DATEADD(year, @TotalYear,@BirthDate),GetDate()) / 30.436875E)
set @TotalDays= FLOOR(DATEDIFF(DAY, DATEADD(month, @TotalMonths,DATEADD(year,
@TotalYear,@BirthDate)), GETDATE()))
set @CurrentDtTime=CONVERT(datetime,CONVERT(varchar(50), DATEPART(year,
GetDate()))+'/' +CONVERT(varchar(50), DATEPART(MONTH, GetDate()))
+'/'+ CONVERT(varchar(50),DATEPART(DAY, GetDate()))+' '
+ CONVERT(varchar(50),DATEPART(HOUR, @BirthDate))+':'+
CONVERT(varchar(50),DATEPART(MINUTE, @BirthDate))+
':'+ CONVERT(varchar(50),DATEPART(Second, @BirthDate)))
set @TotalHours = DATEDIFF(hour, @CurrentDtTime, GETDATE())
if(@TotalHours < 0)
begin
set @TotalHours = DATEDIFF(hour,DATEADD(Day,-1, @CurrentDtTime), GETDATE())
set @TotalDays= @TotalDays -1
end
set @TotalMinute= DATEPART(MINUTE, GETDATE())-DATEPART(MINUTE, @BirthDate)
if(@TotalMinute < 0)
set @TotalMinute = DATEPART(MINUTE, DATEADD(hour,-1,GETDATE()))+(60-DATEPART(MINUTE,
@BirthDate))
set @TotalSecond= DATEPART(Second, GETDATE())-DATEPART(Second, @BirthDate)
Print 'Your age are'+ CHAR(13)
+ CONVERT(varchar(50), @TotalYear)+' Years, ' +
CONVERT(varchar(50),@TotalMonths) +' Months, ' +
CONVERT(varchar(50),@TotalDays)+' Days, ' +
CONVERT(varchar(50),@TotalHours)+' Hours, ' +
CONVERT(varchar(50),@TotalMinute)+' Minutes, ' +
CONVERT(varchar(50),@TotalSecond)+' Seconds. ' +char(13)+
'Your are born at day of week was - ' + CONVERT(varchar(50),DATENAME(dw ,
@BirthDate ))
+char(13)+char(13)+
+'Your Birthdate to till date your '+ CHAR(13)
+'Years - ' + CONVERT(varchar(50), FLOOR(DATEDIFF(DAY, @BirthDate, GETDATE()) /
365.25))
+' , Months - ' + CONVERT(varchar(50),DATEDIFF(MM,@BirthDate,getdate()))
+' , Weeks - ' + CONVERT(varchar(50),DATEDIFF(wk,@BirthDate,getdate()))
+' , Days - ' + CONVERT(varchar(50),DATEDIFF(dd,@BirthDate,getdate()))+char(13)+
+'Hours - ' + CONVERT(varchar(50),DATEDIFF(HH,@BirthDate,getdate()))
+' , Minutes - ' + CONVERT(varchar(50),DATEDIFF(mi,@BirthDate,getdate()))
+' , Seconds - ' + CONVERT(varchar(50),DATEDIFF(ss,@BirthDate,getdate()))
Output
Your age are
22 Years, 0 Months, 2 Days, 11 Hours, 30 Minutes, 16 Seconds.
Your are born at day of week was - Monday
Your Birthdate to till date your
Years - 22 , Months - 264 , Weeks - 1148 , Days - 8037
Hours - 192899 , Minutes - 11573970 , Seconds - 694438216
Extract only right most n letters from a string
var str = "PER 343573";
var right6 = string.IsNullOrWhiteSpace(str) ? string.Empty
: str.Length < 6 ? str
: str.Substring(str.Length - 6); // "343573"
// alternative
var alt_right6 = new string(str.Reverse().Take(6).Reverse().ToArray()); // "343573"
this supports any number of character in the str. the alternative code not support null string. and, the first is faster and the second is more compact.
i prefer the second one if knowing the str containing short string. if it's long string the first one is more suitable.
e.g.
var str = "";
var right6 = string.IsNullOrWhiteSpace(str) ? string.Empty
: str.Length < 6 ? str
: str.Substring(str.Length - 6); // ""
// alternative
var alt_right6 = new string(str.Reverse().Take(6).Reverse().ToArray()); // ""
or
var str = "123";
var right6 = string.IsNullOrWhiteSpace(str) ? string.Empty
: str.Length < 6 ? str
: str.Substring(str.Length - 6); // "123"
// alternative
var alt_right6 = new string(str.Reverse().Take(6).Reverse().ToArray()); // "123"
Differences between strong and weak in Objective-C
strong is the default. An object remains “alive” as long as there is a strong pointer to it.
weak specifies a reference that does not keep the referenced object alive. A weak reference is set to nil when there are no strong references to the object.
Comparing floating point number to zero
2 + 2 = 5(*)
(for some floating-precision values of 2)
This problem frequently arises when we think of"floating point" as a way to increase precision. Then we run afoul of the "floating" part, which means there is no guarantee of which numbers can be represented.
So while we might easily be able to represent "1.0, -1.0, 0.1, -0.1" as we get to larger numbers we start to see approximations - or we should, except we often hide them by truncating the numbers for display.
As a result, we might think the computer is storing "0.003" but it may instead be storing "0.0033333333334".
What happens if you perform "0.0003 - 0.0002"? We expect .0001, but the actual values being stored might be more like "0.00033" - "0.00029" which yields "0.000004", or the closest representable value, which might be 0, or it might be "0.000006".
With current floating point math operations, it is not guaranteed that (a / b) * b == a.
#include <stdio.h>
// defeat inline optimizations of 'a / b * b' to 'a'
extern double bodge(int base, int divisor) {
return static_cast<double>(base) / static_cast<double>(divisor);
}
int main() {
int errors = 0;
for (int b = 1; b < 100; ++b) {
for (int d = 1; d < 100; ++d) {
// b / d * d ... should == b
double res = bodge(b, d) * static_cast<double>(d);
// but it doesn't always
if (res != static_cast<double>(b))
++errors;
}
}
printf("errors: %d\n", errors);
}
ideone reports 599 instances where (b * d) / d != b using just the 10,000 combinations of 1 <= b <= 100 and 1 <= d <= 100 .
The solution described in the FAQ is essentially to apply a granularity constraint - to test if (a == b +/- epsilon).
An alternative approach is to avoid the problem entirely by using fixed point precision or by using your desired granularity as the base unit for your storage. E.g. if you want times stored with nanosecond precision, use nanoseconds as your unit of storage.
C++11 introduced std::ratio as the basis for fixed-point conversions between different time units.
mysql error 2005 - Unknown MySQL server host 'localhost'(11001)
The case is like :
mysql connects will localhost when network is not up.
mysql cannot connect when network is up.
You can try the following steps to diagnose and resolve the issue (my guess is that some other service is blocking port on which mysql is hosted):
- Disconnect the network.
- Stop mysql service (if windows, try from services.msc window)
- Connect to network.
- Try to start the mysql and see if it starts correctly.
- Check for system logs anyways to be sure that there is no error in starting mysql service.
- If all goes well try connecting.
- If fails, try to do a telnet localhost 3306 and see what output it shows.
- Try changing the port on which mysql is hosted, default 3306, you can change to some other port which is ununsed.
This should ideally resolve the issue you are facing.
Creating a timer in python
I want to create a kind of stopwatch that when minutes reach 20 minutes, brings up a dialog box.
All you need is to sleep the specified time. time.sleep() takes seconds to sleep, so 20 * 60 is 20 minutes.
import time
run = raw_input("Start? > ")
time.sleep(20 * 60)
your_code_to_bring_up_dialog_box()
How does strtok() split the string into tokens in C?
strtok maintains a static, internal reference pointing to the next available token in the string; if you pass it a NULL pointer, it will work from that internal reference.
This is the reason strtok isn't re-entrant; as soon as you pass it a new pointer, that old internal reference gets clobbered.
Python - How to concatenate to a string in a for loop?
That's not how you do it.
>>> ''.join(['first', 'second', 'other'])
'firstsecondother'
is what you want.
If you do it in a for loop, it's going to be inefficient as string "addition"/concatenation doesn't scale well (but of course it's possible):
>>> mylist = ['first', 'second', 'other']
>>> s = ""
>>> for item in mylist:
... s += item
...
>>> s
'firstsecondother'
Why do we always prefer using parameters in SQL statements?
Using parameters helps prevent SQL Injection attacks when the database is used in conjunction with a program interface such as a desktop program or web site.
In your example, a user can directly run SQL code on your database by crafting statements in txtSalary.
For example, if they were to write 0 OR 1=1, the executed SQL would be
SELECT empSalary from employee where salary = 0 or 1=1
whereby all empSalaries would be returned.
Further, a user could perform far worse commands against your database, including deleting it If they wrote 0; Drop Table employee:
SELECT empSalary from employee where salary = 0; Drop Table employee
The table employee would then be deleted.
In your case, it looks like you're using .NET. Using parameters is as easy as:
string sql = "SELECT empSalary from employee where salary = @salary";
using (SqlConnection connection = new SqlConnection(/* connection info */))
using (SqlCommand command = new SqlCommand(sql, connection))
{
var salaryParam = new SqlParameter("salary", SqlDbType.Money);
salaryParam.Value = txtMoney.Text;
command.Parameters.Add(salaryParam);
var results = command.ExecuteReader();
}
Dim sql As String = "SELECT empSalary from employee where salary = @salary"
Using connection As New SqlConnection("connectionString")
Using command As New SqlCommand(sql, connection)
Dim salaryParam = New SqlParameter("salary", SqlDbType.Money)
salaryParam.Value = txtMoney.Text
command.Parameters.Add(salaryParam)
Dim results = command.ExecuteReader()
End Using
End Using
Edit 2016-4-25:
As per George Stocker's comment, I changed the sample code to not use AddWithValue. Also, it is generally recommended that you wrap IDisposables in using statements.
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required?
I have encountered the same problem several times. After enabling less secure app option the problem resolved. Enable less secure app from here: https://myaccount.google.com/lesssecureapps
hope this will help.
Javascript String to int conversion
This is to do with JavaScript's + in operator - if a number and a string are "added" up, the number is converted into a string:
0 + 1; //1
'0' + 1; // '01'
To solve this, use the + unary operator, or use parseInt():
+'0' + 1; // 1
parseInt('0', 10) + 1; // 1
The unary + operator converts it into a number (however if it's a decimal it will retain the decimal places), and parseInt() is self-explanatory (converts into number, ignoring decimal places).
The second argument is necessary for parseInt() to use the correct base when leading 0s are placed:
parseInt('010'); // 8 in older browsers, 10 in newer browsers
parseInt('010', 10); // always 10 no matter what
There's also parseFloat() if you need to convert decimals in strings to their numeric value - + can do that too but it behaves slightly differently: that's another story though.
List all files in one directory PHP
You are looking for the command scandir.
$path = '/tmp';
$files = scandir($path);
Following code will remove . and .. from the returned array from scandir:
$files = array_diff(scandir($path), array('.', '..'));
Difference between @Before, @BeforeClass, @BeforeEach and @BeforeAll
import org.junit.Assert
import org.junit.Before
import org.junit.BeforeClass
import org.junit.Test
class FeatureTest {
companion object {
private lateinit var heavyFeature: HeavyFeature
@BeforeClass
@JvmStatic
fun beforeHeavy() {
heavyFeature = HeavyFeature()
}
}
private lateinit var feature: Feature
@Before
fun before() {
feature = Feature()
}
@Test
fun testCool() {
Assert.assertTrue(heavyFeature.cool())
Assert.assertTrue(feature.cool())
}
@Test
fun testWow() {
Assert.assertTrue(heavyFeature.wow())
Assert.assertTrue(feature.wow())
}
}
Same as
import org.junit.Assert
import org.junit.Test
class FeatureTest {
companion object {
private val heavyFeature = HeavyFeature()
}
private val feature = Feature()
@Test
fun testCool() {
Assert.assertTrue(heavyFeature.cool())
Assert.assertTrue(feature.cool())
}
@Test
fun testWow() {
Assert.assertTrue(heavyFeature.wow())
Assert.assertTrue(feature.wow())
}
}
Right HTTP status code to wrong input
According to the below scenario ,
Let's say that someone makes a request to your server with data that is in the correct format, but is simply not "good" data. So for example, imagine that someone posted a String value to an API endpoint that expected a String value; but, the value of the string contained data that was blacklisted (ex. preventing people from using "password" as their password). then the status code could be either 400 or 422 ?
Until now, I would have returned a "400 Bad Request", which, according to the w3.org, means:
The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications.
This description doesn't quite fit the circumstance; but, if you go by the list of core HTTP status codes defined in the HTTP/1.1 protocol, it's probably your best bet.
Recently, however, Someone from my Dev team pointed out [to me] that popular APIs are starting to use HTTP extensions to get more granular with their error reporting. Specifically, many APIs, like Twitter and Recurly, are using the status code "422 Unprocessable Entity" as defined in the HTTP extension for WebDAV. HTTP status code 422 states:
The 422 (Unprocessable Entity) status code means the server understands the content type of the request entity (hence a 415 (Unsupported Media Type) status code is inappropriate), and the syntax of the request entity is correct (thus a 400 (Bad Request) status code is inappropriate) but was unable to process the contained instructions. For example, this error condition may occur if an XML request body contains well-formed (i.e., syntactically correct), but semantically erroneous, XML instructions.
Going back to our password example from above, this 422 status code feels much more appropriate. The server understands what you're trying to do; and it understands the data that you're submitting; it simply won't let that data be processed.
Access blocked by CORS policy: Response to preflight request doesn't pass access control check
If you are using Spring as Back-End server and especially using Spring Security then i found a solution by putting http.cors(); in the configure method. The method looks like that:
protected void configure(HttpSecurity http) throws Exception {
http
.csrf().disable()
.authorizeRequests() // authorize
.anyRequest().authenticated() // all requests are authenticated
.and()
.httpBasic();
http.cors();
}
using batch echo with special characters
Why not use single quote?
echo '<?xml version="1.0" encoding="utf-8" ?>'
output
<?xml version="1.0" encoding="utf-8" ?>
Convert a String of Hex into ASCII in Java
String hexToAscii(String s) {
int n = s.length();
StringBuilder sb = new StringBuilder(n / 2);
for (int i = 0; i < n; i += 2) {
char a = s.charAt(i);
char b = s.charAt(i + 1);
sb.append((char) ((hexToInt(a) << 4) | hexToInt(b)));
}
return sb.toString();
}
private static int hexToInt(char ch) {
if ('a' <= ch && ch <= 'f') { return ch - 'a' + 10; }
if ('A' <= ch && ch <= 'F') { return ch - 'A' + 10; }
if ('0' <= ch && ch <= '9') { return ch - '0'; }
throw new IllegalArgumentException(String.valueOf(ch));
}
How to perform a LEFT JOIN in SQL Server between two SELECT statements?
SELECT [UserID] FROM [User] u LEFT JOIN (
SELECT [TailUser], [Weight] FROM [Edge] WHERE [HeadUser] = 5043) t on t.TailUser=u.USerID
What is the T-SQL syntax to connect to another SQL Server?
Try PowerShell Type like:
$cn = new-object system.data.SqlClient.SQLConnection("Data Source=server1;Initial Catalog=db1;User ID=user1;Password=password1");
$cmd = new-object system.data.sqlclient.sqlcommand("exec Proc1", $cn);
$cn.Open();
$cmd.CommandTimeout = 0
$cmd.ExecuteNonQuery()
$cn.Close();
JPA Query selecting only specific columns without using Criteria Query?
I suppose you could look at this link if I understood your question correctly http://www.javacodegeeks.com/2012/07/ultimate-jpa-queries-and-tips-list-part_09.html
For example they created a query like:
select id, name, age, a.id as ADDRESS_ID, houseNumber, streetName ' +
20' from person p join address a on a.id = p.address_id where p.id = 1'
API pagination best practices
Option A: Keyset Pagination with a Timestamp
In order to avoid the drawbacks of offset pagination you have mentioned, you can use keyset based pagination. Usually, the entities have a timestamp that states their creation or modification time. This timestamp can be used for pagination: Just pass the timestamp of the last element as the query parameter for the next request. The server, in turn, uses the timestamp as a filter criterion (e.g. WHERE modificationDate >= receivedTimestampParameter)
{
"elements": [
{"data": "data", "modificationDate": 1512757070}
{"data": "data", "modificationDate": 1512757071}
{"data": "data", "modificationDate": 1512757072}
],
"pagination": {
"lastModificationDate": 1512757072,
"nextPage": "https://domain.de/api/elements?modifiedSince=1512757072"
}
}
This way, you won't miss any element. This approach should be good enough for many use cases. However, keep the following in mind:
- You may run into endless loops when all elements of a single page have the same timestamp.
- You may deliver many elements multiple times to the client when elements with the same timestamp are overlapping two pages.
You can make those drawbacks less likely by increasing the page size and using timestamps with millisecond precision.
Option B: Extended Keyset Pagination with a Continuation Token
To handle the mentioned drawbacks of the normal keyset pagination, you can add an offset to the timestamp and use a so-called "Continuation Token" or "Cursor". The offset is the position of the element relative to the first element with the same timestamp. Usually, the token has a format like Timestamp_Offset. It's passed to the client in the response and can be submitted back to the server in order to retrieve the next page.
{
"elements": [
{"data": "data", "modificationDate": 1512757070}
{"data": "data", "modificationDate": 1512757072}
{"data": "data", "modificationDate": 1512757072}
],
"pagination": {
"continuationToken": "1512757072_2",
"nextPage": "https://domain.de/api/elements?continuationToken=1512757072_2"
}
}
The token "1512757072_2" points to the last element of the page and states "the client already got the second element with the timestamp 1512757072". This way, the server knows where to continue.
Please mind that you have to handle cases where the elements got changed between two requests. This is usually done by adding a checksum to the token. This checksum is calculated over the IDs of all elements with this timestamp. So we end up with a token format like this: Timestamp_Offset_Checksum.
For more information about this approach check out the blog post "Web API Pagination with Continuation Tokens". A drawback of this approach is the tricky implementation as there are many corner cases that have to be taken into account. That's why libraries like continuation-token can be handy (if you are using Java/a JVM language). Disclaimer: I'm the author of the post and a co-author of the library.
how to realize countifs function (excel) in R
Here an example with 100000 rows (occupations are set here from A to Z):
> a = data.frame(sex=sample(c("M", "F"), 100000, replace=T), occupation=sample(LETTERS, 100000, replace=T))
> sum(a$sex == "M" & a$occupation=="A")
[1] 1882
returns the number of males with occupation "A".
EDIT
As I understand from your comment, you want the counts of all possible combinations of sex and occupation. So first create a dataframe with all combinations:
combns = expand.grid(c("M", "F"), LETTERS)
and loop with apply to sum for your criteria and append the results to combns:
combns = cbind (combns, apply(combns, 1, function(x)sum(a$sex==x[1] & a$occupation==x[2])))
colnames(combns) = c("sex", "occupation", "count")
The first rows of your result look as follows:
sex occupation count
1 M A 1882
2 F A 1869
3 M B 1866
4 F B 1904
5 M C 1979
6 F C 1910
Does this solve your problem?
OR:
Much easier solution suggested by thelatemai:
table(a$sex, a$occupation)
A B C D E F G H I J K L M N O
F 1869 1904 1910 1907 1894 1940 1964 1907 1918 1892 1962 1933 1886 1960 1972
M 1882 1866 1979 1904 1895 1845 1946 1905 1999 1994 1933 1950 1876 1856 1911
P Q R S T U V W X Y Z
F 1908 1907 1883 1888 1943 1922 2016 1962 1885 1898 1889
M 1928 1938 1916 1927 1972 1965 1946 1903 1965 1974 1906
No connection could be made because the target machine actively refused it 127.0.0.1:3446
With this error I was able to trace it, thanks to @Yaur, you need to basically check the service (WCF) if it's running and also check the outbound and inbound TCP properties on your advance firewall settings.
How to delete mysql database through shell command
Try the following command:
mysqladmin -h[hostname/localhost] -u[username] -p[password] drop [database]
This Handler class should be static or leaks might occur: IncomingHandler
I'm confused. The example I found avoids the static property entirely and uses the UI thread:
public class example extends Activity {
final int HANDLE_FIX_SCREEN = 1000;
public Handler DBthreadHandler = new Handler(Looper.getMainLooper()){
@Override
public void handleMessage(Message msg) {
int imsg;
imsg = msg.what;
if (imsg == HANDLE_FIX_SCREEN) {
doSomething();
}
}
};
}
The thing I like about this solution is there is no problem trying to mix class and method variables.
How to scroll table's "tbody" independent of "thead"?
I saw this post about a month ago when I was having similar problems. I needed y-axis scrolling for a table inside of a ui dialog (yes, you heard me right). I was lucky, in that a working solution presented itself fairly quickly. However, it wasn't long before the solution took on a life of its own, but more on that later.
The problem with just setting the top level elements (thead, tfoot, and tbody) to display block, is that browser synchronization of the column sizes between the various components is quickly lost and everything packs to the smallest permissible size. Setting the widths of the columns seems like the best course of action, but without setting the widths of all the internal table components to match the total of these columns, even with a fixed table layout, there is a slight divergence between the headers and body when a scroll bar is present.
The solution for me was to set all the widths, check if a scroll bar was present, and then take the scaled widths the browser had actually decided on, and copy those to the header and footer adjusting the last column width for the size of the scroll bar. Doing this provides some fluidity to the column widths. If changes to the table's width occur, most major browsers will auto-scale the tbody column widths accordingly. All that's left is to set the header and footer column widths from their respective tbody sizes.
$table.find("> thead,> tfoot").find("> tr:first-child")
.each(function(i,e) {
$(e).children().each(function(i,e) {
if (i != column_scaled_widths.length - 1) {
$(e).width(column_scaled_widths[i] - ($(e).outerWidth() - $(e).width()));
} else {
$(e).width(column_scaled_widths[i] - ($(e).outerWidth() - $(e).width()) + $.position.scrollbarWidth());
}
});
});
This fiddle illustrates these notions: http://jsfiddle.net/borgboyone/gbkbhngq/.
Note that a table wrapper or additional tables are not needed for y-axis scrolling alone. (X-axis scrolling does require a wrapping table.) Synchronization between the column sizes for the body and header will still be lost if the minimum pack size for either the header or body columns is encountered. A mechanism for minimum widths should be provided if resizing is an option or small table widths are expected.
The ultimate culmination from this starting point is fully realized here: http://borgboyone.github.io/jquery-ui-table/
A.
String comparison in Python: is vs. ==
See This question
Your logic in reading
For all built-in Python objects (like strings, lists, dicts, functions, etc.), if x is y, then x==y is also True.
is slightly flawed.
If is applies then == will be True, but it does NOT apply in reverse. == may yield True while is yields False.
Eclipse fonts and background color
If you go to Windows, Preferences then select General, Editors, Text editors, you can set colors on that property page (and there's a link for setting MORE colors - General, Appearance, Colors and fonts).
That's with an Eclipse 3.3 build anyway.
how to call an ASP.NET c# method using javascript
You will need to do an Ajax call I suspect. Here is an example of an Ajax called made by jQuery to get you started. The Code logs in a user to my system but returns a bool as to whether it was successful or not. Note the ScriptMethod and WebMethod attributes on the code behind method.
in markup:
var $Username = $("#txtUsername").val();
var $Password = $("#txtPassword").val();
//Call the approve method on the code behind
$.ajax({
type: "POST",
url: "Pages/Mobile/Login.aspx/LoginUser",
data: "{'Username':'" + $Username + "', 'Password':'" + $Password + "' }", //Pass the parameter names and values
contentType: "application/json; charset=utf-8",
dataType: "json",
async: true,
error: function (jqXHR, textStatus, errorThrown) {
alert("Error- Status: " + textStatus + " jqXHR Status: " + jqXHR.status + " jqXHR Response Text:" + jqXHR.responseText) },
success: function (msg) {
if (msg.d == true) {
window.location.href = "Pages/Mobile/Basic/Index.aspx";
}
else {
//show error
alert('login failed');
}
}
});
In Code Behind:
/// <summary>
/// Logs in the user
/// </summary>
/// <param name="Username">The username</param>
/// <param name="Password">The password</param>
/// <returns>true if login successful</returns>
[WebMethod, ScriptMethod]
public static bool LoginUser( string Username, string Password )
{
try
{
StaticStore.CurrentUser = new User( Username, Password );
//check the login details were correct
if ( StaticStore.CurrentUser.IsAuthentiacted )
{
//change the status to logged in
StaticStore.CurrentUser.LoginStatus = Objects.Enums.LoginStatus.LoggedIn;
//Store the user ID in the list of active users
( HttpContext.Current.Application[ SessionKeys.ActiveUsers ] as Dictionary<string, int> )[ HttpContext.Current.Session.SessionID ] = StaticStore.CurrentUser.UserID;
return true;
}
else
{
return false;
}
}
catch ( Exception ex )
{
return false;
}
}
Can't Autowire @Repository annotated interface in Spring Boot
Sometimes I had the same issues when I forget to add Lombok annotation processor dependency to the maven configuration
Using partial views in ASP.net MVC 4
Change the code where you load the partial view to:
@Html.Partial("_CreateNote", new QuickNotes.Models.Note())
This is because the partial view is expecting a Note but is getting passed the model of the parent view which is the IEnumerable
find -mtime files older than 1 hour
What about -mmin?
find /var/www/html/audio -daystart -maxdepth 1 -mmin +59 -type f -name "*.mp3" \
-exec rm -f {} \;
From man find:
-mmin n
File's data was last modified n minutes ago.
Also, make sure to test this first!
... -exec echo rm -f '{}' \;
^^^^ Add the 'echo' so you just see the commands that are going to get
run instead of actual trying them first.
Split string and get first value only
string valueStr = "title, genre, director, actor";
var vals = valueStr.Split(',')[0];
vals will give you the title
Difference between a theta join, equijoin and natural join
While the answers explaining the exact differences are fine, I want to show how the relational algebra is transformed to SQL and what the actual value of the 3 concepts is.
The key concept in your question is the idea of a join. To understand a join you need to understand a Cartesian Product (the example is based on SQL where the equivalent is called a cross join as onedaywhen points out);
This isn't very useful in practice. Consider this example.
Product(PName, Price)
====================
Laptop, 1500
Car, 20000
Airplane, 3000000
Component(PName, CName, Cost)
=============================
Laptop, CPU, 500
Laptop, hdd, 300
Laptop, case, 700
Car, wheels, 1000
The Cartesian product Product x Component will be - bellow or sql fiddle. You can see there are 12 rows = 3 x 4. Obviously, rows like "Laptop" with "wheels" have no meaning, this is why in practice the Cartesian product is rarely used.
| PNAME | PRICE | CNAME | COST |
--------------------------------------
| Laptop | 1500 | CPU | 500 |
| Laptop | 1500 | hdd | 300 |
| Laptop | 1500 | case | 700 |
| Laptop | 1500 | wheels | 1000 |
| Car | 20000 | CPU | 500 |
| Car | 20000 | hdd | 300 |
| Car | 20000 | case | 700 |
| Car | 20000 | wheels | 1000 |
| Airplane | 3000000 | CPU | 500 |
| Airplane | 3000000 | hdd | 300 |
| Airplane | 3000000 | case | 700 |
| Airplane | 3000000 | wheels | 1000 |
JOINs are here to add more value to these products. What we really want is to "join" the product with its associated components, because each component belongs to a product. The way to do this is with a join:
Product JOIN Component ON Pname
The associated SQL query would be like this (you can play with all the examples here)
SELECT *
FROM Product
JOIN Component
ON Product.Pname = Component.Pname
and the result:
| PNAME | PRICE | CNAME | COST |
----------------------------------
| Laptop | 1500 | CPU | 500 |
| Laptop | 1500 | hdd | 300 |
| Laptop | 1500 | case | 700 |
| Car | 20000 | wheels | 1000 |
Notice that the result has only 4 rows, because the Laptop has 3 components, the Car has 1 and the Airplane none. This is much more useful.
Getting back to your questions, all the joins you ask about are variations of the JOIN I just showed:
Natural Join = the join (the ON clause) is made on all columns with the same name; it removes duplicate columns from the result, as opposed to all other joins; most DBMS (database systems created by various vendors such as Microsoft's SQL Server, Oracle's MySQL etc. ) don't even bother supporting this, it is just bad practice (or purposely chose not to implement it). Imagine that a developer comes and changes the name of the second column in Product from Price to Cost. Then all the natural joins would be done on PName AND on Cost, resulting in 0 rows since no numbers match.
Theta Join = this is the general join everybody uses because it allows you to specify the condition (the ON clause in SQL). You can join on pretty much any condition you like, for example on Products that have the first 2 letters similar, or that have a different price. In practice, this is rarely the case - in 95% of the cases you will join on an equality condition, which leads us to:
Equi Join = the most common one used in practice. The example above is an equi join. Databases are optimized for this type of joins! The oposite of an equi join is a non-equi join, i.e. when you join on a condition other than "=". Databases are not optimized for this! Both of them are subsets of the general theta join. The natural join is also a theta join but the condition (the theta) is implicit.
Source of information: university + certified SQL Server developer + recently completed the MOO "Introduction to databases" from Stanford so I dare say I have relational algebra fresh in mind.
What’s the best way to load a JSONObject from a json text file?
On Google'e Gson library, for having a JsonObject, or more abstract a JsonElement:
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
JsonElement json = JsonParser.parseReader( new InputStreamReader(new FileInputStream("/someDir/someFile.json"), "UTF-8") );
This is not demanding a given Object structure for receiving/reading the json string.
How to trigger checkbox click event even if it's checked through Javascript code?
Getting check status
var checked = $("#selectall").is(":checked");
Then for setting
$("input:checkbox").attr("checked",checked);
How to create a GUID in Excel?
The formula for French Excel:
=CONCATENER(
DECHEX(ALEA.ENTRE.BORNES(0;4294967295);8);"-";
DECHEX(ALEA.ENTRE.BORNES(0;42949);4);"-";
DECHEX(ALEA.ENTRE.BORNES(0;42949);4);"-";
DECHEX(ALEA.ENTRE.BORNES(0;42949);4);"-";
DECHEX(ALEA.ENTRE.BORNES(0;4294967295);8);
DECHEX(ALEA.ENTRE.BORNES(0;42949);4))
As noted by Josh M, this does not provide a compliant GUID however, but this works well for my current need.
"Unable to get the VLookup property of the WorksheetFunction Class" error
I was having the same problem. It seems that passing Me.ComboBox1.Value as an argument for the Vlookup function is causing the issue. What I did was assign this value to a double and then put it into the Vlookup function.
Dim x As Double
x = Me.ComboBox1.Value
Me.TextBox1.Value = Application.WorksheetFunction.VLookup(x, Worksheets("Sheet3").Range("Names"), 2, False)
Or, for a shorter method, you can just convert the type within the Vlookup function using Cdbl(<Value>).
So it would end up being
Me.TextBox1.Value = Application.WorksheetFunction.VLookup(Cdbl(Me.ComboBox1.Value), Worksheets("Sheet3").Range("Names"), 2, False)
Strange as it may sound, it works for me.
Hope this helps.
How do you reverse a string in place in C or C++?
Note that the beauty of std::reverse is that it works with char * strings and std::wstrings just as well as std::strings
void strrev(char *str)
{
if (str == NULL)
return;
std::reverse(str, str + strlen(str));
}
OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection
Once you have detected the bounding box of the document, you can perform a four-point perspective transform to obtain a top-down birds eye view of the image. This will fix the skew and isolate only the desired object.
Input image:
Detected text object
Top-down view of text document
Code
from imutils.perspective import four_point_transform
import cv2
import numpy
# Load image, grayscale, Gaussian blur, Otsu's threshold
image = cv2.imread("1.png")
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (7,7), 0)
thresh = cv2.threshold(blur, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)[1]
# Find contours and sort for largest contour
cnts = cv2.findContours(thresh, cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
cnts = cnts[0] if len(cnts) == 2 else cnts[1]
cnts = sorted(cnts, key=cv2.contourArea, reverse=True)
displayCnt = None
for c in cnts:
# Perform contour approximation
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.02 * peri, True)
if len(approx) == 4:
displayCnt = approx
break
# Obtain birds' eye view of image
warped = four_point_transform(image, displayCnt.reshape(4, 2))
cv2.imshow("thresh", thresh)
cv2.imshow("warped", warped)
cv2.imshow("image", image)
cv2.waitKey()
Regular expression "^[a-zA-Z]" or "[^a-zA-Z]"
^[a-zA-Z] means any a-z or A-Z at the start of a line
[^a-zA-Z] means any character that IS NOT a-z OR A-Z
Dynamically access object property using variable
You can achieve this in quite a few different ways.
let foo = {
bar: 'Hello World'
};
foo.bar;
foo['bar'];
The bracket notation is specially powerful as it let's you access a property based on a variable:
let foo = {
bar: 'Hello World'
};
let prop = 'bar';
foo[prop];
This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:
let foo = {
bar: 'Hello World',
baz: 'How are you doing?',
last: 'Quite alright'
};
for (let prop in foo.getOwnPropertyNames()) {
console.log(foo[prop]);
}
Both dot and bracket notation also work as expected for nested objects:
let foo = {
bar: {
baz: 'Hello World'
}
};
foo.bar.baz;
foo['bar']['baz'];
foo.bar['baz'];
foo['bar'].baz;
Object destructuring
We could also consider object destructuring as a means to access a property in an object, but as follows:
let foo = {
bar: 'Hello World',
baz: 'How are you doing?',
last: 'Quite alright'
};
let prop = 'last';
let { bar, baz, [prop]: customName } = foo;
// bar = 'Hello World'
// baz = 'How are you doing?'
// customName = 'Quite alright'
How do I install a JRE or JDK to run the Android Developer Tools on Windows 7?
You can go here to download the Java JRE.
You can go here to download the Java JDK.
After that you need to set up your environmental variables in Windows:
- Right-click My Computer
- Click Properties
- Go to Advanced System Settings
- Click on the Advanced tab
- Click on Environment Variables
EDIT: See screenshot for environmental variables
How to resolve "Could not find schema information for the element/attribute <xxx>"?
What fixed the "Could not find schema information for the element ..." for me was
- Opening my
app.config. - Right-clicking in the editor window and selecting
Properties. - In the properties box, there is a row called
Schemas, I clicked that row and selected the browse...box that appears in the row. - I simply checked the
usebox for all the rows that had my project somewhere in them, and also for the current version of .Net I was using. For instance:DotNetConfig30.xsd.
After that everything went to working fine.
How those schema rows with my project got unchecked I'm not sure, but when I made sure they were checked, I was back in business.
What is the best way to measure execution time of a function?
I would definitely advise you to have a look at System.Diagnostics.Stopwatch
And when I looked around for more about Stopwatch I found this site;
There mentioned another possibility
Process.TotalProcessorTime
Reset CSS display property to default value
Concerning the answer by BoltClock and John, I personally had issues with the initial keyword when using IE11. It works fine in Chrome, but in IE it seems to have no effect.
According to this answer IE does not support the initial keyword: Div display:initial not working as intended in ie10 and chrome 29
I tried setting it blank instead as suggested here: how to revert back to normal after display:none for table row
This worked and was good enough for my scenario. Of course to set the real initial value the above answer is the only good one I could find.
How to import cv2 in python3?
The best way is to create a virtual env. first and then do pip install , everything will work fine
How can I change eclipse's Internal Browser from IE to Firefox on Windows XP?
In Preferences -> General -> Web Browser, there is the option "Use internal web browser". Select "Use external web browser" instead and check "Firefox".
How to revert to origin's master branch's version of file
If you didn't commit it to the master branch yet, its easy:
- get off the master branch (like
git checkout -b oops/fluke/dang) - commit your changes there (like
git add -u; git commit;) - go back the master branch (like
git checkout master)
Your changes will be saved in branch oops/fluke/dang; master will be as it was.
Converting a PDF to PNG
Out of all the available alternatives I found Inkscape to produce the most accurate results when converting PDFs to PNG. Especially when the source file had transparent layers, Inkscape succeeded where Imagemagick and other tools failed.
This is the command I use:
inkscape "$pdf" -z --export-dpi=600 --export-area-drawing --export-png="$pngfile"
And here it is implemented in a script:
#!/bin/bash
while [ $# -gt 0 ]; do
pdf=$1
echo "Converting "$pdf" ..."
pngfile=`echo "$pdf" | sed 's/\.\w*$/.png/'`
inkscape "$pdf" -z --export-dpi=600 --export-area-drawing --export-png="$pngfile"
echo "Converted to "$pngfile""
shift
done
echo "All jobs done. Exiting."
Stopping Excel Macro executution when pressing Esc won't work
I also like to use MsgBox for debugging, and I've run into this same issue more than once. Now I always add a Cancel button to the popup, and exit the macro if Cancel is pressed. Example code:
If MsgBox("Debug message", vbOKCancel, "Debugging") = vbCancel Then Exit Sub
Display alert message and redirect after click on accept
that worked but try it this way.
echo "<script>
alert('There are no fields to generate a report');
window.location.href='admin/ahm/panel';
</script>";
alert on top then location next
Configure cron job to run every 15 minutes on Jenkins
Your syntax is slightly wrong. Say:
*/15 * * * * command
|
|--> `*/15` would imply every 15 minutes.
* indicates that the cron expression matches for all values of the field.
/ describes increments of ranges.
What is the purpose of Looper and how to use it?
A Looper has a synchronized MessageQueue that's used to process Messages placed on the queue.
It implements a Thread Specific Storage Pattern.
Only one Looper per Thread. Key methods include prepare(),loop() and quit().
prepare() initializes the current Thread as a Looper. prepare() is static method that uses the ThreadLocal class as shown below.
public static void prepare(){
...
sThreadLocal.set
(new Looper());
}
prepare()must be called explicitly before running the event loop.loop()runs the event loop which waits for Messages to arrive on a specific Thread's messagequeue. Once the next Message is received,theloop()method dispatches the Message to its target handlerquit()shuts down the event loop. It doesn't terminate the loop,but instead it enqueues a special message
Looper can be programmed in a Thread via several steps
Extend
ThreadCall
Looper.prepare()to initialize Thread as aLooperCreate one or more
Handler(s) to process the incoming messages- Call
Looper.loop()to process messages until the loop is told toquit().
Element count of an array in C++
I know is old topic but what about simple solution like while loop?
int function count(array[]) {
int i = 0;
while(array[i] != NULL) {
i++;
}
return i;
}
I know that is slower than sizeof() but this is another example of array count.
Delete rows containing specific strings in R
You could use dplyr::filter() and negate a grepl() match:
library(dplyr)
df %>%
filter(!grepl('REVERSE', Name))
Or with dplyr::filter() and negating a stringr::str_detect() match:
library(stringr)
df %>%
filter(!str_detect(Name, 'REVERSE'))
Word wrap for a label in Windows Forms
- Put the label inside a panel
Handle the
ClientSizeChanged eventfor the panel, making the label fill the space:private void Panel2_ClientSizeChanged(object sender, EventArgs e) { label1.MaximumSize = new Size((sender as Control).ClientSize.Width - label1.Left, 10000); }Set
Auto-Sizefor the label totrue- Set
Dockfor the label toFill
Border around each cell in a range
You can also include this task within another macro, without opening a new one:
I don't put Sub and end Sub, because the macro contains much longer code, as per picture below
With Sheets("1_PL").Range("EF1631:JJ1897")
With .Borders
.LineStyle = xlContinuous
.Color = vbBlack
.Weight = xlThin
End With
[![enter image description here][1]][1]End With
Can I use Class.newInstance() with constructor arguments?
You can use the getDeclaredConstructor method of Class. It expects an array of classes. Here is a tested and working example:
public static JFrame createJFrame(Class c, String name, Component parentComponent)
{
try
{
JFrame frame = (JFrame)c.getDeclaredConstructor(new Class[] {String.class}).newInstance("name");
if (parentComponent != null)
{
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
else
{
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
}
frame.setLocationRelativeTo(parentComponent);
frame.pack();
frame.setVisible(true);
}
catch (InstantiationException instantiationException)
{
ExceptionHandler.handleException(instantiationException, parentComponent, Language.messages.get(Language.InstantiationExceptionKey), c.getName());
}
catch(NoSuchMethodException noSuchMethodException)
{
//ExceptionHandler.handleException(noSuchMethodException, parentComponent, Language.NoSuchMethodExceptionKey, "NamedConstructor");
ExceptionHandler.handleException(noSuchMethodException, parentComponent, Language.messages.get(Language.NoSuchMethodExceptionKey), "(Constructor or a JFrame method)");
}
catch (IllegalAccessException illegalAccessException)
{
ExceptionHandler.handleException(illegalAccessException, parentComponent, Language.messages.get(Language.IllegalAccessExceptionKey));
}
catch (InvocationTargetException invocationTargetException)
{
ExceptionHandler.handleException(invocationTargetException, parentComponent, Language.messages.get(Language.InvocationTargetExceptionKey));
}
finally
{
return null;
}
}
How to retrieve a module's path?
I don't get why no one is talking about this, but to me the simplest solution is using imp.find_module("modulename") (documentation here):
import imp
imp.find_module("os")
It gives a tuple with the path in second position:
(<open file '/usr/lib/python2.7/os.py', mode 'U' at 0x7f44528d7540>,
'/usr/lib/python2.7/os.py',
('.py', 'U', 1))
The advantage of this method over the "inspect" one is that you don't need to import the module to make it work, and you can use a string in input. Useful when checking modules called in another script for example.
EDIT:
In python3, importlib module should do:
Doc of importlib.util.find_spec:
Return the spec for the specified module.
First, sys.modules is checked to see if the module was already imported. If so, then sys.modules[name].spec is returned. If that happens to be set to None, then ValueError is raised. If the module is not in sys.modules, then sys.meta_path is searched for a suitable spec with the value of 'path' given to the finders. None is returned if no spec could be found.
If the name is for submodule (contains a dot), the parent module is automatically imported.
The name and package arguments work the same as importlib.import_module(). In other words, relative module names (with leading dots) work.
SQL Server: Importing database from .mdf?
Apart from steps mentioned in posted answers by @daniele3004 above, I had to open SSMS as Administrator otherwise it was showing Primary file is read only error.
Go to Start Menu , navigate to SSMS link , right click on the SSMS link , select Run As Administrator. Then perform the above steps.
Could not load type 'System.Runtime.CompilerServices.ExtensionAttribute' from assembly 'mscorlib
In my case I had an issue around using Microsoft.ReportViewer.WebForms. I removed validate=true from add verb line in web.config and it started working:
<system.web>
<httpHandlers>
<add verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
Read input numbers separated by spaces
int main() {
int sum = 0;
cout << "enter number" << endl;
int i = 0;
while (true) {
cin >> i;
sum += i;
//cout << i << endl;
if (cin.peek() == '\n') {
break;
}
}
cout << "result: " << sum << endl;
return 0;
}
I think this code works, you may enter any int numbers and spaces, it will calculate the sum of input ints
undefined reference to 'vtable for class' constructor
You're declaring a virtual function and not defining it:
virtual void calculateCredits();
Either define it or declare it as:
virtual void calculateCredits() = 0;
Or simply:
virtual void calculateCredits() { };
Read more about vftable: http://en.wikipedia.org/wiki/Virtual_method_table
Markdown and including multiple files
I would just mention that you can use the cat command to concatenate the input files prior to piping them to markdown_py which has the same effect as what pandoc does with multiple input files coming in.
cat *.md | markdown_py > youroutputname.html
works pretty much the same as the pandoc example above for the Python version of Markdown on my Mac.
Change Orientation of Bluestack : portrait/landscape mode
I install go launcher on mine, (Windows 8)=> preferences => Screens => Screen orientation => vertical (disable QWE keyboard)
Shuffle an array with python, randomize array item order with python
import random
random.shuffle(array)
document.createElement("script") synchronously
This works for modern 'evergreen' browsers that support async/await and fetch.
This example is simplified, without error handling, to show the basic principals at work.
// This is a modern JS dependency fetcher - a "webpack" for the browser
const addDependentScripts = async function( scriptsToAdd ) {
// Create an empty script element
const s=document.createElement('script')
// Fetch each script in turn, waiting until the source has arrived
// before continuing to fetch the next.
for ( var i = 0; i < scriptsToAdd.length; i++ ) {
let r = await fetch( scriptsToAdd[i] )
// Here we append the incoming javascript text to our script element.
s.text += await r.text()
}
// Finally, add our new script element to the page. It's
// during this operation that the new bundle of JS code 'goes live'.
document.querySelector('body').appendChild(s)
}
// call our browser "webpack" bundler
addDependentScripts( [
'https://code.jquery.com/jquery-3.5.1.slim.min.js',
'https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js'
] )
How to compile without warnings being treated as errors?
Remove -Werror from your Make or CMake files, as suggested in this post
Maven build debug in Eclipse
The Run/Debug configuration you're using is meant to let you run Maven on your workspace as if from the command line without leaving Eclipse.
Assuming your tests are JUnit based you should be able to debug them by choosing a source folder containing tests with the right button and choose Debug as... -> JUnit tests.
BeautifulSoup getText from between <p>, not picking up subsequent paragraphs
You are getting close!
# Find all of the text between paragraph tags and strip out the html
page = soup.find('p').getText()
Using find (as you've noticed) stops after finding one result. You need find_all if you want all the paragraphs. If the pages are formatted consistently ( just looked over one), you could also use something like
soup.find('div',{'id':'ctl00_PlaceHolderMain_RichHtmlField1__ControlWrapper_RichHtmlField'})
to zero in on the body of the article.
Is it safe to shallow clone with --depth 1, create commits, and pull updates again?
See some of the answers to my similar question why-cant-i-push-from-a-shallow-clone and the link to the recent thread on the git list.
Ultimately, the 'depth' measurement isn't consistent between repos, because they measure from their individual HEADs, rather than (a) your Head, or (b) the commit(s) you cloned/fetched, or (c) something else you had in mind.
The hard bit is getting one's Use Case right (i.e. self-consistent), so that distributed, and therefore probably divergent repos will still work happily together.
It does look like the checkout --orphan is the right 'set-up' stage, but still lacks clean (i.e. a simple understandable one line command) guidance on the "clone" step. Rather it looks like you have to init a repo, set up a remote tracking branch (you do want the one branch only?), and then fetch that single branch, which feels long winded with more opportunity for mistakes.
Edit: For the 'clone' step see this answer
SQL/mysql - Select distinct/UNIQUE but return all columns?
Try
SELECT table.* FROM table
WHERE otherField = 'otherValue'
GROUP BY table.fieldWantedToBeDistinct
limit x
Code for a simple JavaScript countdown timer?
Expanding upon the accepted answer, your machine going to sleep, etc. may delay the timer from working. You can get a true time, at the cost of a little processing. This will give a true time left.
<span id="timer"></span>
<script>
var now = new Date();
var timeup = now.setSeconds(now.getSeconds() + 30);
//var timeup = now.setHours(now.getHours() + 1);
var counter = setInterval(timer, 1000);
function timer() {
now = new Date();
count = Math.round((timeup - now)/1000);
if (now > timeup) {
window.location = "/logout"; //or somethin'
clearInterval(counter);
return;
}
var seconds = Math.floor((count%60));
var minutes = Math.floor((count/60) % 60);
document.getElementById("timer").innerHTML = minutes + ":" + seconds;
}
</script>
How to pretty-print a numpy.array without scientific notation and with given precision?
I use
def np_print(array,fmt="10.5f"):
print (array.size*("{:"+fmt+"}")).format(*array)
It's not difficult to modify it for multi-dimensional arrays.
htmlentities() vs. htmlspecialchars()
You probably want to use some Unicode character encoding, for example UTF-8, and htmlspecialchars. Because there isn't any need to generate "HTML entities" for "all [the] applicable characters" (that is what htmlentities does according to the documentation) if it's already in your character set.
Conversion between UTF-8 ArrayBuffer and String
Using TextEncoder and TextDecoder
var uint8array = new TextEncoder("utf-8").encode("Plain Text");
var string = new TextDecoder().decode(uint8array);
console.log(uint8array ,string )
DataTables: Uncaught TypeError: Cannot read property 'defaults' of undefined
The problem is that dataTable is not defined at the point you are calling this method.
Ensure that you are loading the .js files in the correct order:
<script src="/Scripts/jquery.dataTables.js"></script>
<script src="/Scripts/dataTables.bootstrap.js"></script>
Convert an ArrayList to an object array
Something like the standard Collection.toArray(T[]) should do what you need (note that ArrayList implements Collection):
TypeA[] array = a.toArray(new TypeA[a.size()]);
On a side note, you should consider defining a to be of type List<TypeA> rather than ArrayList<TypeA>, this avoid some implementation specific definition that may not really be applicable for your application.
Also, please see this question about the use of a.size() instead of 0 as the size of the array passed to a.toArray(TypeA[])
Angular2 use [(ngModel)] with [ngModelOptions]="{standalone: true}" to link to a reference to model's property
Using @angular/forms when you use a <form> tag it automatically creates a FormGroup.
For every contained ngModel tagged <input> it will create a FormControl and add it into the FormGroup created above; this FormControl will be named into the FormGroup using attribute name.
Example:
<form #f="ngForm">
<input type="text" [(ngModel)]="firstFieldVariable" name="firstField">
<span>{{ f.controls['firstField']?.value }}</span>
</form>
Said this, the answer to your question follows.
When you mark it as standalone: true this will not happen (it will not be added to the FormGroup).
Reference: https://github.com/angular/angular/issues/9230#issuecomment-228116474
Joining two table entities in Spring Data JPA
@Query("SELECT rd FROM ReleaseDateType rd, CacheMedia cm WHERE ...")
How to perform runtime type checking in Dart?
object.runtimeType returns the type of object
For example:
print("HELLO".runtimeType); //prints String
var x=0.0;
print(x.runtimeType); //prints double
Why can't I define my workbook as an object?
It's actually a sensible question. Here's the answer from Excel 2010 help:
"The Workbook object is a member of the Workbooks collection. The Workbooks collection contains all the Workbook objects currently open in Microsoft Excel."
So, since that workbook isn't open - at least I assume it isn't - it can't be set as a workbook object. If it was open you'd just set it like:
Set wbk = workbooks("Master Benchmark Data Sheet.xlsx")
Maven in Eclipse: step by step installation
I was having problems because I was looking to install the Maven plugin on MuleStudio not Eclipse..
[for MuleStudio 1.2 or below do steps (1) and (2) otherwise jump to step (2)]
Instructions for MuleStudio (ONLY versions 1.2 and below): (1) Help >install new software...
Helios Update Site - http://download.eclipse.org/releases/helios/
Instructions for MuleStudio (1.3) OR Eclipse: (2) Help >install new software...
Maven - URL: http://download.eclipse.org/technology/m2e/releases
How do I use floating-point division in bash?
How to do floating point calculations in bash:
Instead of using "here strings" (<<<) with the bc command, like one of the most-upvoted examples does, here's my favorite bc floating point example, right from the EXAMPLES section of the bc man pages (see man bc for the manual pages).
Before we begin, know that an equation for pi is: pi = 4*atan(1). a() below is the bc math function for atan().
This is how to store the result of a floating point calculation into a bash variable--in this case into a variable called
pi. Note thatscale=10sets the number of decimal digits of precision to 10 in this case. Any decimal digits after this place are truncated.pi=$(echo "scale=10; 4*a(1)" | bc -l)Now, to have a single line of code that also prints out the value of this variable, simply add the
echocommand to the end as a follow-up command, as follows. Note the truncation at 10 decimal places, as commanded:pi=$(echo "scale=10; 4*a(1)" | bc -l); echo $pi 3.1415926532Finally, let's throw in some rounding. Here we will use the
printffunction to round to 4 decimal places. Note that the3.14159...rounds now to3.1416. Since we are rounding, we no longer need to usescale=10to truncate to 10 decimal places, so we'll just remove that part. Here's the end solution:pi=$(printf %.4f $(echo "4*a(1)" | bc -l)); echo $pi 3.1416
Here's another really great application and demo of the above techniques: measuring and printing run-time.
(See also my other answer here).
Note that dt_min gets rounded from 0.01666666666... to 0.017:
start=$SECONDS; sleep 1; end=$SECONDS; dt_sec=$(( end - start )); dt_min=$(printf %.3f $(echo "$dt_sec/60" | bc -l)); echo "dt_sec = $dt_sec; dt_min = $dt_min"
dt_sec = 1; dt_min = 0.017
Related:
- [my answer] https://unix.stackexchange.com/questions/52313/how-to-get-execution-time-of-a-script-effectively/547849#547849
- [my question] What do three left angle brackets (`<<<`) mean in bash?
- https://unix.stackexchange.com/questions/80362/what-does-mean/80368#80368
- https://askubuntu.com/questions/179898/how-to-round-decimals-using-bc-in-bash/574474#574474
Android M - check runtime permission - how to determine if the user checked "Never ask again"?
I found to many long and confusing answer and after reading few of the answers My conclusion is
if (!ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.READ_EXTERNAL_STORAGE))
Toast.makeText(this, "permanently denied", Toast.LENGTH_SHORT).show();
Remove '\' char from string c#
to remove all '\' from a string, simply do the following:
myString = myString.Replace("\\", "");
SQL DELETE with INNER JOIN
Add .* to s in your first line.
Try:
DELETE s.* FROM spawnlist s
INNER JOIN npc n ON s.npc_templateid = n.idTemplate
WHERE (n.type = "monster");
How to convert an address into a Google Maps Link (NOT MAP)
The C# Replace method usually works for me:
foo = "http://maps.google.com/?q=" + address.Text.Replace(" ","+");
Prevent cell numbers from incrementing in a formula in Excel
Highlight "B1" and press F4. This will lock the cell.
Now you can drag it around and it will not change. The principle is simple. It adds a dollar sign before both coordinates. A dollar sign in front of a coordinate will lock it when you copy the formula around. You can have partially locked coordinates and fully locked coordinates.
Change the background color of a pop-up dialog
Credit goes to Sushil
Create your AlertDialog as usual:
AlertDialog.Builder dialog = new AlertDialog.Builder(getContext());
Dialog dialog = dialog.create();
dialog.show();
After calling show() on your dialog, set the background color like this:
dialog.getWindow().setBackgroundDrawableResource(android.R.color.background_dark);
Euclidean distance of two vectors
If you want to use less code, you can also use the norm in the stats package (the 'F' stands for Forbenius, which is the Euclidean norm):
norm(matrix(x1-x2), 'F')
While this may look a bit neater, it's not faster. Indeed, a quick test on very large vectors shows little difference, though so12311's method is slightly faster. We first define:
set.seed(1234)
x1 <- rnorm(300000000)
x2 <- rnorm(300000000)
Then testing for time yields the following:
> system.time(a<-sqrt(sum((x1-x2)^2)))
user system elapsed
1.02 0.12 1.18
> system.time(b<-norm(matrix(x1-x2), 'F'))
user system elapsed
0.97 0.33 1.31
Triggering change detection manually in Angular
I used accepted answer reference and would like to put an example, since Angular 2 documentation is very very hard to read, I hope this is easier:
Import
NgZone:import { Component, NgZone } from '@angular/core';Add it to your class constructor
constructor(public zone: NgZone, ...args){}Run code with
zone.run:this.zone.run(() => this.donations = donations)
Use JSTL forEach loop's varStatus as an ID
The variable set by varStatus is a LoopTagStatus object, not an int. Use:
<div id="divIDNo${theCount.index}">
To clarify:
${theCount.index}starts counting at0unless you've set thebeginattribute${theCount.count}starts counting at1
Logical operators for boolean indexing in Pandas
TLDR; Logical Operators in Pandas are &, | and ~, and parentheses (...) is important!
Python's and, or and not logical operators are designed to work with scalars. So Pandas had to do one better and override the bitwise operators to achieve vectorized (element-wise) version of this functionality.
So the following in python (exp1 and exp2 are expressions which evaluate to a boolean result)...
exp1 and exp2 # Logical AND
exp1 or exp2 # Logical OR
not exp1 # Logical NOT
...will translate to...
exp1 & exp2 # Element-wise logical AND
exp1 | exp2 # Element-wise logical OR
~exp1 # Element-wise logical NOT
for pandas.
If in the process of performing logical operation you get a ValueError, then you need to use parentheses for grouping:
(exp1) op (exp2)
For example,
(df['col1'] == x) & (df['col2'] == y)
And so on.
Boolean Indexing: A common operation is to compute boolean masks through logical conditions to filter the data. Pandas provides three operators: & for logical AND, | for logical OR, and ~ for logical NOT.
Consider the following setup:
np.random.seed(0)
df = pd.DataFrame(np.random.choice(10, (5, 3)), columns=list('ABC'))
df
A B C
0 5 0 3
1 3 7 9
2 3 5 2
3 4 7 6
4 8 8 1
Logical AND
For df above, say you'd like to return all rows where A < 5 and B > 5. This is done by computing masks for each condition separately, and ANDing them.
Overloaded Bitwise & Operator
Before continuing, please take note of this particular excerpt of the docs, which state
Another common operation is the use of boolean vectors to filter the data. The operators are:
|foror,&forand, and~fornot. These must be grouped by using parentheses, since by default Python will evaluate an expression such asdf.A > 2 & df.B < 3asdf.A > (2 & df.B) < 3, while the desired evaluation order is(df.A > 2) & (df.B < 3).
So, with this in mind, element wise logical AND can be implemented with the bitwise operator &:
df['A'] < 5
0 False
1 True
2 True
3 True
4 False
Name: A, dtype: bool
df['B'] > 5
0 False
1 True
2 False
3 True
4 True
Name: B, dtype: bool
(df['A'] < 5) & (df['B'] > 5)
0 False
1 True
2 False
3 True
4 False
dtype: bool
And the subsequent filtering step is simply,
df[(df['A'] < 5) & (df['B'] > 5)]
A B C
1 3 7 9
3 4 7 6
The parentheses are used to override the default precedence order of bitwise operators, which have higher precedence over the conditional operators < and >. See the section of Operator Precedence in the python docs.
If you do not use parentheses, the expression is evaluated incorrectly. For example, if you accidentally attempt something such as
df['A'] < 5 & df['B'] > 5
It is parsed as
df['A'] < (5 & df['B']) > 5
Which becomes,
df['A'] < something_you_dont_want > 5
Which becomes (see the python docs on chained operator comparison),
(df['A'] < something_you_dont_want) and (something_you_dont_want > 5)
Which becomes,
# Both operands are Series...
something_else_you_dont_want1 and something_else_you_dont_want2Which throws
ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().
So, don't make that mistake!1
Avoiding Parentheses Grouping
The fix is actually quite simple. Most operators have a corresponding bound method for DataFrames. If the individual masks are built up using functions instead of conditional operators, you will no longer need to group by parens to specify evaluation order:
df['A'].lt(5)
0 True
1 True
2 True
3 True
4 False
Name: A, dtype: bool
df['B'].gt(5)
0 False
1 True
2 False
3 True
4 True
Name: B, dtype: bool
df['A'].lt(5) & df['B'].gt(5)
0 False
1 True
2 False
3 True
4 False
dtype: bool
See the section on Flexible Comparisons.. To summarise, we have
+------------------------------+
¦ ¦ Operator ¦ Function ¦
¦----+------------+------------¦
¦ 0 ¦ > ¦ gt ¦
+----+------------+------------¦
¦ 1 ¦ >= ¦ ge ¦
+----+------------+------------¦
¦ 2 ¦ < ¦ lt ¦
+----+------------+------------¦
¦ 3 ¦ <= ¦ le ¦
+----+------------+------------¦
¦ 4 ¦ == ¦ eq ¦
+----+------------+------------¦
¦ 5 ¦ != ¦ ne ¦
+------------------------------+
Another option for avoiding parentheses is to use DataFrame.query (or eval):
df.query('A < 5 and B > 5')
A B C
1 3 7 9
3 4 7 6
I have extensively documented query and eval in Dynamic Expression Evaluation in pandas using pd.eval().
operator.and_
Allows you to perform this operation in a functional manner. Internally calls Series.__and__ which corresponds to the bitwise operator.
import operator
operator.and_(df['A'] < 5, df['B'] > 5)
# Same as,
# (df['A'] < 5).__and__(df['B'] > 5)
0 False
1 True
2 False
3 True
4 False
dtype: bool
df[operator.and_(df['A'] < 5, df['B'] > 5)]
A B C
1 3 7 9
3 4 7 6
You won't usually need this, but it is useful to know.
Generalizing: np.logical_and (and logical_and.reduce)
Another alternative is using np.logical_and, which also does not need parentheses grouping:
np.logical_and(df['A'] < 5, df['B'] > 5)
0 False
1 True
2 False
3 True
4 False
Name: A, dtype: bool
df[np.logical_and(df['A'] < 5, df['B'] > 5)]
A B C
1 3 7 9
3 4 7 6
np.logical_and is a ufunc (Universal Functions), and most ufuncs have a reduce method. This means it is easier to generalise with logical_and if you have multiple masks to AND. For example, to AND masks m1 and m2 and m3 with &, you would have to do
m1 & m2 & m3
However, an easier option is
np.logical_and.reduce([m1, m2, m3])
This is powerful, because it lets you build on top of this with more complex logic (for example, dynamically generating masks in a list comprehension and adding all of them):
import operator
cols = ['A', 'B']
ops = [np.less, np.greater]
values = [5, 5]
m = np.logical_and.reduce([op(df[c], v) for op, c, v in zip(ops, cols, values)])
m
# array([False, True, False, True, False])
df[m]
A B C
1 3 7 9
3 4 7 6
1 - I know I'm harping on this point, but please bear with me. This is a very, very common beginner's mistake, and must be explained very thoroughly.
Logical OR
For the df above, say you'd like to return all rows where A == 3 or B == 7.
Overloaded Bitwise |
df['A'] == 3
0 False
1 True
2 True
3 False
4 False
Name: A, dtype: bool
df['B'] == 7
0 False
1 True
2 False
3 True
4 False
Name: B, dtype: bool
(df['A'] == 3) | (df['B'] == 7)
0 False
1 True
2 True
3 True
4 False
dtype: bool
df[(df['A'] == 3) | (df['B'] == 7)]
A B C
1 3 7 9
2 3 5 2
3 4 7 6
If you haven't yet, please also read the section on Logical AND above, all caveats apply here.
Alternatively, this operation can be specified with
df[df['A'].eq(3) | df['B'].eq(7)]
A B C
1 3 7 9
2 3 5 2
3 4 7 6
operator.or_
Calls Series.__or__ under the hood.
operator.or_(df['A'] == 3, df['B'] == 7)
# Same as,
# (df['A'] == 3).__or__(df['B'] == 7)
0 False
1 True
2 True
3 True
4 False
dtype: bool
df[operator.or_(df['A'] == 3, df['B'] == 7)]
A B C
1 3 7 9
2 3 5 2
3 4 7 6
np.logical_or
For two conditions, use logical_or:
np.logical_or(df['A'] == 3, df['B'] == 7)
0 False
1 True
2 True
3 True
4 False
Name: A, dtype: bool
df[np.logical_or(df['A'] == 3, df['B'] == 7)]
A B C
1 3 7 9
2 3 5 2
3 4 7 6
For multiple masks, use logical_or.reduce:
np.logical_or.reduce([df['A'] == 3, df['B'] == 7])
# array([False, True, True, True, False])
df[np.logical_or.reduce([df['A'] == 3, df['B'] == 7])]
A B C
1 3 7 9
2 3 5 2
3 4 7 6
Logical NOT
Given a mask, such as
mask = pd.Series([True, True, False])
If you need to invert every boolean value (so that the end result is [False, False, True]), then you can use any of the methods below.
Bitwise ~
~mask
0 False
1 False
2 True
dtype: bool
Again, expressions need to be parenthesised.
~(df['A'] == 3)
0 True
1 False
2 False
3 True
4 True
Name: A, dtype: bool
This internally calls
mask.__invert__()
0 False
1 False
2 True
dtype: bool
But don't use it directly.
operator.inv
Internally calls __invert__ on the Series.
operator.inv(mask)
0 False
1 False
2 True
dtype: bool
np.logical_not
This is the numpy variant.
np.logical_not(mask)
0 False
1 False
2 True
dtype: bool
Note, np.logical_and can be substituted for np.bitwise_and, logical_or with bitwise_or, and logical_not with invert.
Right to Left support for Twitter Bootstrap 3
you can use my project i create bootstrap 3 rtl with sass and gulp so you can easely customize it https://github.com/z-avanes/bootstrap3-rtl
Including a css file in a blade template?
You should try this :
{{ Html::style('css/styles.css') }}
OR
<link href="{{ asset('css/styles.css') }}" rel="stylesheet">
Hope this help for you !!!
How can I create an executable JAR with dependencies using Maven?
Taking Unanswered's answer and reformatting it, we have:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
</plugins>
</build>
Next, I would recommend making this a natural part of your build, rather than something to call explicitly. To make this a integral part of your build, add this plugin to your pom.xml and bind it to the package lifecycle event. However, a gotcha is that you need to call the assembly:single goal if putting this in your pom.xml, while you would call 'assembly:assembly' if executing it manually from the command line.
<project>
[...]
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-my-jar-with-dependencies</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
[...]
</plugins>
[...]
</build>
</project>
Where do I find the current C or C++ standard documents?
The text of a draft of the ANSI C standard (aka C.89) is available online. This was standardized by the ANSI committee prior to acceptance by the ISO C Standard (C.90), so the numbering of the sections differ (ANSI sections 2 through 4 correspond roughly to ISO sections 5 through 7), although the content is (supposed to be) largely identical.
Merge (with squash) all changes from another branch as a single commit
Another option is git merge --squash <feature branch> then finally do a git commit.
From Git merge
--squash
--no-squashProduce the working tree and index state as if a real merge happened (except for the merge information), but do not actually make a commit or move the
HEAD, nor record$GIT_DIR/MERGE_HEADto cause the nextgit commitcommand to create a merge commit. This allows you to create a single commit on top of the current branch whose effect is the same as merging another branch (or more in case of an octopus).
How to change bower's default components folder?
Create a Bower configuration file .bowerrc in the project root (as opposed to your home directory) with the content:
{
"directory" : "public/components"
}
Run bower install again.
Laravel Redirect Back with() Message
Laravel 5.8
Controller
return back()->with('error', 'Incorrect username or password.');
Blade
@if (Session::has('error'))
<div class="alert alert-warning" role="alert">
{{Session::get('error')}}
</div>
@endif
Error: could not find function "%>%"
On Windows: if you use %>% inside a %dopar% loop, you have to add a reference to load package dplyr (or magrittr, which dplyr loads).
Example:
plots <- foreach(myInput=iterators::iter(plotCount), .packages=c("RODBC", "dplyr")) %dopar%
{
return(getPlot(myInput))
}
If you omit the .packages command, and use %do% instead to make it all run in a single process, then works fine. The reason is that it all runs in one process, so it doesn't need to specifically load new packages.
jQuery changing style of HTML element
you could also specify multiple style values like this
$('#navigation ul li').css({'display': 'inline-block','background-color': '#ff0000', 'color': '#ffffff'});
Tomcat startup logs - SEVERE: Error filterStart how to get a stack trace?
Setting up log4j logging for Tomcat is pretty simple. The following is quoted from http://tomcat.apache.org/tomcat-5.5-doc/logging.html :
Create a file called log4j.properties with the following content and save it into common/classes.
log4j.rootLogger=DEBUG, R log4j.appender.R=org.apache.log4j.RollingFileAppender log4j.appender.R.File=${catalina.home}/logs/tomcat.log log4j.appender.R.MaxFileSize=10MB log4j.appender.R.MaxBackupIndex=10 log4j.appender.R.layout=org.apache.log4j.PatternLayout log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%nDownload Log4J (v1.2 or later) and place the log4j jar in $CATALINA_HOME/common/lib.
- Download Commons Logging and place the commons-logging-x.y.z.jar (not commons-logging-api-x.y.z.jar) in $CATALINA_HOME/common/lib with the log4j jar.
- Start Tomcat
You might also want to have a look at http://wiki.apache.org/tomcat/FAQ/Logging
Is there a function to round a float in C or do I need to write my own?
As Rob mentioned, you probably just want to print the float to 1 decimal place. In this case, you can do something like the following:
#include <stdio.h>
#include <stdlib.h>
int main()
{
float conver = 45.592346543;
printf("conver is %0.1f\n",conver);
return 0;
}
If you want to actually round the stored value, that's a little more complicated. For one, your one-decimal-place representation will rarely have an exact analog in floating-point. If you just want to get as close as possible, something like this might do the trick:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
float conver = 45.592346543;
printf("conver is %0.1f\n",conver);
conver = conver*10.0f;
conver = (conver > (floor(conver)+0.5f)) ? ceil(conver) : floor(conver);
conver = conver/10.0f;
//If you're using C99 or better, rather than ANSI C/C89/C90, the following will also work.
//conver = roundf(conver*10.0f)/10.0f;
printf("conver is now %f\n",conver);
return 0;
}
I doubt this second example is what you're looking for, but I included it for completeness. If you do require representing your numbers in this way internally, and not just on output, consider using a fixed-point representation instead.
Getting HTML elements by their attribute names
Just another answer
Array.prototype.filter.call(
document.getElementsByTagName('span'),
function(el) {return el.getAttribute('property') == 'v.name';}
);
In future
Array.prototype.filter.call(
document.getElementsByTagName('span'),
(el) => el.getAttribute('property') == 'v.name'
)
3rd party edit
Intro
The call() method calls a function with a given this value and arguments provided individually.
The filter() method creates a new array with all elements that pass the test implemented by the provided function.
Given this html markup
<span property="a">apple - no match</span>
<span property="v:name">onion - match</span>
<span property="b">root - match</span>
<span property="v:name">tomato - match</span>
<br />
<button onclick="findSpan()">find span</button>
you can use this javascript
function findSpan(){
var spans = document.getElementsByTagName('span');
var spansV = Array.prototype.filter.call(
spans,
function(el) {return el.getAttribute('property') == 'v:name';}
);
return spansV;
}
See demo
Best practices with STDIN in Ruby?
It seems most answers are assuming the arguments are filenames containing content to be cat'd to the stdin. Below everything is treated as just arguments. If STDIN is from the TTY, then it is ignored.
$ cat tstarg.rb
while a=(ARGV.shift or (!STDIN.tty? and STDIN.gets) )
puts a
end
Either arguments or stdin can be empty or have data.
$ cat numbers
1
2
3
4
5
$ ./tstarg.rb a b c < numbers
a
b
c
1
2
3
4
5
Can I disable a CSS :hover effect via JavaScript?
There isn’t a pure JavaScript generic solution, I’m afraid. JavaScript isn’t able to turn off the CSS :hover state itself.
You could try the following alternative workaround though. If you don’t mind mucking about in your HTML and CSS a little bit, it saves you having to reset every CSS property manually via JavaScript.
HTML
<body class="nojQuery">
CSS
/* Limit the hover styles in your CSS so that they only apply when the nojQuery
class is present */
body.nojQuery ul#mainFilter a:hover {
/* CSS-only hover styles go here */
}
JavaScript
// When jQuery kicks in, remove the nojQuery class from the <body> element, thus
// making the CSS hover styles disappear.
$(function(){}
$('body').removeClass('nojQuery');
)
The SELECT permission was denied on the object 'Users', database 'XXX', schema 'dbo'
Check space of your database.this error comes when space increased compare to space given to database.
Mailx send html message
Well, the "-a" mail and mailx in Centos7 is "attach file" not "append header." My shortest path to a solution on Centos7 from here: stackexchange.com
Basically:
yum install mutt
mutt -e 'set content_type=text/html' -s 'My subject' [email protected] < msg.html
Sort Java Collection
You can also use:
Collections.sort(list, new Comparator<CustomObject>() {
public int compare(CustomObject obj1, CustomObject obj2) {
return obj1.id - obj2.id;
}
});
System.out.println(list);
How to make cross domain request
You can make cross domain requests using the XMLHttpRequest object. This is done using something called "Cross Origin Resource Sharing". See:
http://en.wikipedia.org/wiki/Cross-origin_resource_sharing
Very simply put, when the request is made to the server the server can respond with a Access-Control-Allow-Origin header which will either allow or deny the request. The browser needs to check this header and if it is allowed then it will continue with the request process. If not the browser will cancel the request.
You can find some more information and a working example here: http://www.leggetter.co.uk/2010/03/12/making-cross-domain-javascript-requests-using-xmlhttprequest-or-xdomainrequest.html
JSONP is an alternative solution, but you could argue it's a bit of a hack.
MetadataException when using Entity Framework Entity Connection
I had the same error message, and the problem was also the metadata part of the connection string, but I had to dig a little deeper to solve it and wanted to share this little nugget:
The metadata string is made up of three sections that each look like this:
res://
(assembly)/
(model name).(ext)
Where ext is "csdl", "ssdl", and "msl".
For most people, assembly can probably be "*", which seems to indicate that all loaded assemblies will be searched (I haven't done a huge amount of testing of this). This part wasn't an issue for me, so I can't comment on whether you need the assembly name or file name (i.e., with or without ".dll"), though I have seen both suggested.
The model name part should be the name and namespace of your .edmx file, relative to your assembly. So if you have a My.DataAccess assembly and you create DataModels.edmx in a Models folder, its full name is My.DataAccess.Models.DataModels. In this case, you would have "Models.DataModels.(ext)" in your metadata.
If you ever move or rename your .edmx file, you will need to update your metadata string manually (in my experience), and remembering to change the relative namespace will save a few headaches.
Show/Hide Table Rows using Javascript classes
Below is my Script which show/hide table row with id "agencyrow".
<script type="text/javascript">
function showhiderow() {
if (document.getElementById("<%=RadioButton1.ClientID %>").checked == true) {
document.getElementById("agencyrow").style.display = '';
} else {
document.getElementById("agencyrow").style.display = 'none';
}
}
</script>
Just call function showhiderow()upon radiobutton onClick event
What is the difference between Visual Studio Express 2013 for Windows and Visual Studio Express 2013 for Windows Desktop?
A comparison between the different Visual Studio Express editions can be found at Visual Studio Express (archive.org link). The difference between Windows and Windows Desktop is that with the Windows edition you can build Windows Store Apps (using .NET, WPF/XAML) while the Windows Desktop edition allows you to write classic Windows Desktop applications. It is possible to install both products on the same machine.
Visual Studio Express 2010 allows you to build Windows Desktop applications. Writing Windows Store applications is not possible with this product.
For learning I would suggest Notepad and the command line. While an IDE provides significant productivity enhancements to professionals, it can be intimidating to a beginner. If you want to use an IDE nevertheless I would recommend Visual Studio Express 2013 for Windows Desktop.
Update 2015-07-27: In addition to the Express Editions, Microsoft now offers Community Editions. These are still free for individual developers, open source contributors, and small teams. There are no Web, Windows, and Windows Desktop releases anymore either; the Community Edition can be used to develop any app type. In addition, the Community Edition does support (3rd party) Add-ins. The Community Edition offers the same functionality as the commercial Professional Edition.
Regex pattern including all special characters
(^\W$)
^ - start of the string, \W - match any non-word character [^a-zA-Z0-9_], $ - end of the string
How to check if array is empty or does not exist?
You want to do the check for undefined first. If you do it the other way round, it will generate an error if the array is undefined.
if (array === undefined || array.length == 0) {
// array empty or does not exist
}
Update
This answer is getting a fair amount of attention, so I'd like to point out that my original answer, more than anything else, addressed the wrong order of the conditions being evaluated in the question. In this sense, it fails to address several scenarios, such as null values, other types of objects with a length property, etc. It is also not very idiomatic JavaScript.
The foolproof approach
Taking some inspiration from the comments, below is what I currently consider to be the foolproof way to check whether an array is empty or does not exist. It also takes into account that the variable might not refer to an array, but to some other type of object with a length property.
if (!Array.isArray(array) || !array.length) {
// array does not exist, is not an array, or is empty
// ? do not attempt to process array
}
To break it down:
Array.isArray(), unsurprisingly, checks whether its argument is an array. This weeds out values likenull,undefinedand anything else that is not an array.
Note that this will also eliminate array-like objects, such as theargumentsobject and DOMNodeListobjects. Depending on your situation, this might not be the behavior you're after.The
array.lengthcondition checks whether the variable'slengthproperty evaluates to a truthy value. Because the previous condition already established that we are indeed dealing with an array, more strict comparisons likearray.length != 0orarray.length !== 0are not required here.
The pragmatic approach
In a lot of cases, the above might seem like overkill. Maybe you're using a higher order language like TypeScript that does most of the type-checking for you at compile-time, or you really don't care whether the object is actually an array, or just array-like.
In those cases, I tend to go for the following, more idiomatic JavaScript:
if (!array || !array.length) {
// array or array.length are falsy
// ? do not attempt to process array
}
Or, more frequently, its inverse:
if (array && array.length) {
// array and array.length are truthy
// ? probably OK to process array
}
With the introduction of the optional chaining operator (Elvis operator) in ECMAScript 2020, this can be shortened even further:
if (!array?.length) {
// array or array.length are falsy
// ? do not attempt to process array
}
Or the opposite:
if (array?.length) {
// array and array.length are truthy
// ? probably OK to process array
}
string encoding and decoding?
You can't decode a unicode, and you can't encode a str. Try doing it the other way around.
How to get row number in dataframe in Pandas?
To get all indices that matches 'Smith'
>>> df[df['LastName'] == 'Smith'].index
Int64Index([1], dtype='int64')
or as a numpy array
>>> df[df['LastName'] == 'Smith'].index.to_numpy() # .values on older versions
array([1])
or if there is only one and you want the integer, you can subset
>>> df[df['LastName'] == 'Smith'].index[0]
1
You could use the same boolean expressions with .loc, but it is not needed unless you also want to select a certain column, which is redundant when you only want the row number/index.
Changing variable names with Python for loops
Use a list.
groups = [0]*3
for i in xrange(3):
groups[i] = self.getGroup(selected, header + i)
or more "Pythonically":
groups = [self.getGroup(selected, header + i) for i in xrange(3)]
For what it's worth, you could try to create variables the "wrong" way, i.e. by modifying the dictionary which holds their values:
l = locals()
for i in xrange(3):
l['group' + str(i)] = self.getGroup(selected, header + i)
but that's really bad form, and possibly not even guaranteed to work.
How update the _id of one MongoDB Document?
Here I have a solution that avoid multiple requests, for loops and old document removal.
You can easily create a new idea manually using something like:_id:ObjectId()
But knowing Mongo will automatically assign an _id if missing, you can use aggregate to create a $project containing all the fields of your document, but omit the field _id. You can then save it with $out
So if your document is:
{
"_id":ObjectId("5b5ed345cfbce6787588e480"),
"title": "foo",
"description": "bar"
}
Then your query will be:
db.getCollection('myCollection').aggregate([
{$match:
{_id: ObjectId("5b5ed345cfbce6787588e480")}
}
{$project:
{
title: '$title',
description: '$description'
}
},
{$out: 'myCollection'}
])
how to stop a loop arduino
The three options that come to mind:
1st) End void loop() with while(1)... or equally as good... while(true)
void loop(){
//the code you want to run once here,
//e.g., If (blah == blah)...etc.
while(1) //last line of main loop
}
This option runs your code once and then kicks the Ard into
an endless "invisible" loop. Perhaps not the nicest way to
go, but as far as outside appearances, it gets the job done.
The Ard will continue to draw current while it spins itself in
an endless circle... perhaps one could set up a sort of timer
function that puts the Ard to sleep after so many seconds,
minutes, etc., of looping... just a thought... there are certainly
various sleep libraries out there... see
e.g., Monk, Programming Arduino: Next Steps, pgs., 85-100
for further discussion of such.
2nd) Create a "stop main loop" function with a conditional control
structure that makes its initial test fail on a second pass.
This often requires declaring a global variable and having the
"stop main loop" function toggle the value of the variable
upon termination. E.g.,
boolean stop_it = false; //global variable
void setup(){
Serial.begin(9600);
//blah...
}
boolean stop_main_loop(){ //fancy stop main loop function
if(stop_it == false){ //which it will be the first time through
Serial.println("This should print once.");
//then do some more blah....you can locate all the
// code you want to run once here....eventually end by
//toggling the "stop_it" variable ...
}
stop_it = true; //...like this
return stop_it; //then send this newly updated "stop_it" value
// outside the function
}
void loop{
stop_it = stop_main_loop(); //and finally catch that updated
//value and store it in the global stop_it
//variable, effectively
//halting the loop ...
}
Granted, this might not be especially pretty, but it also works.
It kicks the Ard into another endless "invisible" loop, but this
time it's a case of repeatedly checking the if(stop_it == false) condition in stop_main_loop()
which of course fails to pass every time after the first time through.
3rd) One could once again use a global variable but use a simple if (test == blah){} structure instead of a fancy "stop main loop" function.
boolean start = true; //global variable
void setup(){
Serial.begin(9600);
}
void loop(){
if(start == true){ //which it will be the first time through
Serial.println("This should print once.");
//the code you want to run once here,
//e.g., more If (blah == blah)...etc.
}
start = false; //toggle value of global "start" variable
//Next time around, the if test is sure to fail.
}
There are certainly other ways to "stop" that pesky endless main loop but these three as well as those already mentioned should get you started.
Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1
That happened to me too, because I was trying to get an IEnumerable but the response had a single value. Please try to make sure it's a list of data in your response. The lines I used (for api url get) to solve the problem are like these:
HttpResponseMessage response = await client.GetAsync("api/yourUrl");
if (response.IsSuccessStatusCode)
{
IEnumerable<RootObject> rootObjects =
awaitresponse.Content.ReadAsAsync<IEnumerable<RootObject>>();
foreach (var rootObject in rootObjects)
{
Console.WriteLine(
"{0}\t${1}\t{2}",
rootObject.Data1, rootObject.Data2, rootObject.Data3);
}
Console.ReadLine();
}
Hope It helps.
How can I make grep print the lines below and above each matching line?
grep's -A 1 option will give you one line after; -B 1 will give you one line before; and -C 1 combines both to give you one line both before and after, -1 does the same.
Is it possible to view RabbitMQ message contents directly from the command line?
I wrote rabbitmq-dump-queue which allows dumping messages from a RabbitMQ queue to local files and requeuing the messages in their original order.
Example usage (to dump the first 50 messages of queue incoming_1):
rabbitmq-dump-queue -url="amqp://user:[email protected]:5672/" -queue=incoming_1 -max-messages=50 -output-dir=/tmp
unary operator expected in shell script when comparing null value with string
Since the value of $var is the empty string, this:
if [ $var == $var1 ]; then
expands to this:
if [ == abcd ]; then
which is a syntax error.
You need to quote the arguments:
if [ "$var" == "$var1" ]; then
You can also use = rather than ==; that's the original syntax, and it's a bit more portable.
If you're using bash, you can use the [[ syntax, which doesn't require the quotes:
if [[ $var = $var1 ]]; then
Even then, it doesn't hurt to quote the variable reference, and adding quotes:
if [[ "$var" = "$var1" ]]; then
might save a future reader a moment trying to remember whether [[ ... ]] requires them.
How to show first commit by 'git log'?
git log --format="%h" | tail -1 gives you the commit hash (ie 0dd89fb), which you can feed into other commands, by doing something like
git diff `git log --format="%h" --after="1 day"| tail -1`..HEAD to view all the commits in the last day.
Scanning Java annotations at runtime
The Classloader API doesn't have an "enumerate" method, because class loading is an "on-demand" activity -- you usually have thousands of classes in your classpath, only a fraction of which will ever be needed (the rt.jar alone is 48MB nowadays!).
So, even if you could enumerate all classes, this would be very time- and memory-consuming.
The simple approach is to list the concerned classes in a setup file (xml or whatever suits your fancy); if you want to do this automatically, restrict yourself to one JAR or one class directory.
Copy file(s) from one project to another using post build event...VS2010
I use it like this.
xcopy "$(TargetDir)$(TargetName).dll" "$(SolutionDir)Lib\TIRM\x86\" /F /Y
xcopy "$(TargetDir)$(TargetName).lib" "$(SolutionDir)Lib\TIRM\x86\" /F /Y
/F : Copy source is File
/Y : Overwrite and don't ask me
Note the use of this. $(TargetDir) has already '\' "D:\MyProject\bin\" = $(TargetDir)
You can find macro in Command editor
Is there a way to do repetitive tasks at intervals?
How about something like
package main
import (
"fmt"
"time"
)
func schedule(what func(), delay time.Duration) chan bool {
stop := make(chan bool)
go func() {
for {
what()
select {
case <-time.After(delay):
case <-stop:
return
}
}
}()
return stop
}
func main() {
ping := func() { fmt.Println("#") }
stop := schedule(ping, 5*time.Millisecond)
time.Sleep(25 * time.Millisecond)
stop <- true
time.Sleep(25 * time.Millisecond)
fmt.Println("Done")
}
Python virtualenv questions
in my project wsgi.py file i have this code (it works with virtualenv,django,apache2 in windows and python 3.4)
import os
import sys
DJANGO_PATH = os.path.join(os.path.abspath(os.path.dirname(__file__)),'..')
sys.path.append(DJANGO_PATH)
sys.path.append('c:/myproject/env/Scripts')
sys.path.append('c:/myproject/env/Lib/site-packages')
activate_this = 'c:/myproject/env/scripts/activate_this.py'
exec(open(activate_this).read())
from django.core.wsgi import get_wsgi_application
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myproject.settings")
application = get_wsgi_application()
in virtualhost file conf i have
<VirtualHost *:80>
ServerName mysite
WSGIScriptAlias / c:/myproject/myproject/myproject/wsgi.py
DocumentRoot c:/myproject/myproject/
<Directory "c:/myproject/myproject/myproject/">
Options +Indexes +FollowSymLinks +MultiViews
AllowOverride All
Require local
</Directory>
</VirtualHost>
What are the differences between numpy arrays and matrices? Which one should I use?
Just to add one case to unutbu's list.
One of the biggest practical differences for me of numpy ndarrays compared to numpy matrices or matrix languages like matlab, is that the dimension is not preserved in reduce operations. Matrices are always 2d, while the mean of an array, for example, has one dimension less.
For example demean rows of a matrix or array:
with matrix
>>> m = np.mat([[1,2],[2,3]])
>>> m
matrix([[1, 2],
[2, 3]])
>>> mm = m.mean(1)
>>> mm
matrix([[ 1.5],
[ 2.5]])
>>> mm.shape
(2, 1)
>>> m - mm
matrix([[-0.5, 0.5],
[-0.5, 0.5]])
with array
>>> a = np.array([[1,2],[2,3]])
>>> a
array([[1, 2],
[2, 3]])
>>> am = a.mean(1)
>>> am.shape
(2,)
>>> am
array([ 1.5, 2.5])
>>> a - am #wrong
array([[-0.5, -0.5],
[ 0.5, 0.5]])
>>> a - am[:, np.newaxis] #right
array([[-0.5, 0.5],
[-0.5, 0.5]])
I also think that mixing arrays and matrices gives rise to many "happy" debugging hours. However, scipy.sparse matrices are always matrices in terms of operators like multiplication.
Spring 3.0 - Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]
If you already have all dependencies in your pom, try:
1. Remove all downloaded jars form your maven repository folder for 'org->springframework'
2. Make a maven clean build.
Errno 10060] A connection attempt failed because the connected party did not properly respond after a period of time
As ping works, but telnetto port 80 does not, the HTTP port 80 is closed on your machine. I assume that your browser's HTTP connection goes through a proxy (as browsing works, how else would you read stackoverflow?).
You need to add some code to your python program, that handles the proxy, like described here:
Android Studio says "cannot resolve symbol" but project compiles
I had the very same problem recently with Android Studio 1.3. The only working solution was to remove the .gradle and .idea folders and re-import the project into Android Studio.