INSERT with SELECT
The right Syntax for your query is:
INSERT INTO courses (name, location, gid)
SELECT (name, location, gid)
FROM courses
WHERE cid = $cid
'Use of Unresolved Identifier' in Swift
Once I had this problem after renaming a file. I renamed the file from within Xcode, but afterwards Xcode couldn't find the function in the file. Even a clean rebuild didn't fix the problem, but closing and then re-opening the project got the build to work.
Twitter-Bootstrap-2 logo image on top of navbar
Overwrite the brand class, either in the bootstrap.css or a new CSS file, as below -
.brand
{
background: url(images/logo.png) no-repeat left center;
height: 20px;
width: 100px;
}
and your html should look like -
<div class="container-fluid">
<a class="brand" href="index.html"></a>
</div>
Why is list initialization (using curly braces) better than the alternatives?
There are MANY reasons to use brace initialization, but you should be aware that the initializer_list<>
constructor is preferred to the other constructors, the exception being the default-constructor. This leads to problems with constructors and templates where the type T
constructor can be either an initializer list or a plain old ctor.
struct Foo {
Foo() {}
Foo(std::initializer_list<Foo>) {
std::cout << "initializer list" << std::endl;
}
Foo(const Foo&) {
std::cout << "copy ctor" << std::endl;
}
};
int main() {
Foo a;
Foo b(a); // copy ctor
Foo c{a}; // copy ctor (init. list element) + initializer list!!!
}
Assuming you don't encounter such classes there is little reason not to use the intializer list.
Calculate relative time in C#
Jeff, because Stack Overflow uses jQuery extensively, I recommend the jquery.timeago plugin.
Benefits:
- Avoid timestamps dated "1 minute ago" even though the page was opened 10 minutes ago; timeago refreshes automatically.
- You can take full advantage of page and/or fragment caching in your web applications, because the timestamps aren't calculated on the server.
- You get to use microformats like the cool kids.
Just attach it to your timestamps on DOM ready:
jQuery(document).ready(function() {
jQuery('abbr.timeago').timeago();
});
This will turn all abbr
elements with a class of timeago and an ISO 8601 timestamp in the title:
<abbr class="timeago" title="2008-07-17T09:24:17Z">July 17, 2008</abbr>
into something like this:
<abbr class="timeago" title="July 17, 2008">4 months ago</abbr>
which yields: 4 months ago. As time passes, the timestamps will automatically update.
Disclaimer: I wrote this plugin, so I'm biased.
How do I set log4j level on the command line?
log4j does not support this directly.
As you do not want a configuration file, you most likely use programmatic configuration. I would suggest that you look into scanning all the system properties, and explicitly program what you want based on this.
Postgres: SQL to list table foreign keys
I think what you were looking for and very close to what @ollyc wrote is this:
SELECT
tc.constraint_name, tc.table_name, kcu.column_name,
ccu.table_name AS foreign_table_name,
ccu.column_name AS foreign_column_name
FROM
information_schema.table_constraints AS tc
JOIN information_schema.key_column_usage AS kcu
ON tc.constraint_name = kcu.constraint_name
JOIN information_schema.constraint_column_usage AS ccu
ON ccu.constraint_name = tc.constraint_name
WHERE constraint_type = 'FOREIGN KEY' AND ccu.table_name='YourTableNameHere';
This will list all the tables that use your specified table as a foreign key
SQL Column definition : default value and not null redundant?
I would say not.
If the column does accept null values, then there's nothing to stop you inserting a null value into the field. As far as I'm aware, the default value only applies on creation of a new row.
With not null set, then you can't insert a null value into the field as it'll throw an error.
Think of it as a fail safe mechanism to prevent nulls.
Vim: insert the same characters across multiple lines
Suppose you have this file:
something
name
comment
phone
email
something else
and more ...
You want to add "vendor_" in front of "name", "comment", "phone", and "email", regardless of where they appear in the file.
:%s/\<\(name\|comment\|phone\|email\)\>/vendor_\1/gc
The c
flag will prompt you for confirmation. You can drop that if you don't want the prompt.
Moment js date time comparison
I believe you are looking for the query functions, isBefore
, isSame
, and isAfter
.
But it's a bit difficult to tell exactly what you're attempting. Perhaps you are just looking to get the difference between the input time and the current time? If so, consider the difference function, diff
. For example:
moment().diff(date_time, 'minutes')
A few other things:
There's an error in the first line:
var date_time = 2013-03-24 + 'T' + 10:15:20:12 + 'Z'
That's not going to work. I think you meant:
var date_time = '2013-03-24' + 'T' + '10:15:20:12' + 'Z';
Of course, you might as well:
var date_time = '2013-03-24T10:15:20:12Z';
You're using: .tz('UTC')
incorrectly. .tz
belongs to moment-timezone. You don't need to use that unless you're working with other time zones, like America/Los_Angeles
.
If you want to parse a value as UTC, then use:
moment.utc(theStringToParse)
Or, if you want to parse a local value and convert it to UTC, then use:
moment(theStringToParse).utc()
Or perhaps you don't need it at all. Just because the input value is in UTC, doesn't mean you have to work in UTC throughout your function.
You seem to be getting the "now" instance by moment(new Date())
. You can instead just use moment()
.
Updated
Based on your edit, I think you can just do this:
var date_time = req.body.date + 'T' + req.body.time + 'Z';
var isafter = moment(date_time).isAfter('2014-03-24T01:14:00Z');
Or, if you would like to ensure that your fields are validated to be in the correct format:
var m = moment.utc(req.body.date + ' ' + req.body.time, "YYYY-MM-DD HH:mm:ss");
var isvalid = m.isValid();
var isafter = m.isAfter('2014-03-24T01:14:00Z');
"inappropriate ioctl for device"
Most likely it means that the open didn't fail.
When Perl opens a file, it checks whether or not the file is a TTY (so that it can answer the -T $fh
filetest operator) by issuing the TCGETS
ioctl against it. If the file is a regular file and not a tty, the ioctl fails and sets errno to ENOTTY
(string value: "Inappropriate ioctl for device"). As ysth says, the most common reason for seeing an unexpected value in $!
is checking it when it's not valid -- that is, anywhere other than immediately after a syscall failed, so testing the result codes of your operations is critically important.
If open
actually did return false for you, and you found ENOTTY
in $!
then I would consider this a small bug (giving a useless value of $!
) but I would also be very curious as to how it happened. Code and/or truss output would be nifty.
What is the difference between res.end() and res.send()?
res.send()
implements res.write
, res.setHeaders
and res.end
:
- It checks the data you send and sets the correct response headers.
- Then it streams the data with
res.write
.
- Finally, it uses
res.end
to set the end of the request.
There are some cases in which you will want to do this manually, for example, if you want to stream a file or a large data set. In these cases, you will want to set the headers yourself and use res.write
to keep the stream flow.
Python: Find in list
Instead of using list.index(x)
which returns the index of x if it is found in list or returns a #ValueError
message if x is not found, you could use list.count(x)
which returns the number of occurrences of x in list (validation that x is indeed in the list) or it returns 0 otherwise (in the absence of x). The cool thing about count()
is that it doesn't break your code or require you to throw an exception for when x is not found
Select all where [first letter starts with B]
This will work for MYSQL
SELECT Name FROM Employees WHERE Name REGEXP '^[B].*$'
In this REGEXP stands for regular expression
and
this is for T-SQL
SELECT Name FROM Employees WHERE Name LIKE '[B]%'
Renaming column names of a DataFrame in Spark Scala
If structure is flat:
val df = Seq((1L, "a", "foo", 3.0)).toDF
df.printSchema
// root
// |-- _1: long (nullable = false)
// |-- _2: string (nullable = true)
// |-- _3: string (nullable = true)
// |-- _4: double (nullable = false)
the simplest thing you can do is to use toDF
method:
val newNames = Seq("id", "x1", "x2", "x3")
val dfRenamed = df.toDF(newNames: _*)
dfRenamed.printSchema
// root
// |-- id: long (nullable = false)
// |-- x1: string (nullable = true)
// |-- x2: string (nullable = true)
// |-- x3: double (nullable = false)
If you want to rename individual columns you can use either select
with alias
:
df.select($"_1".alias("x1"))
which can be easily generalized to multiple columns:
val lookup = Map("_1" -> "foo", "_3" -> "bar")
df.select(df.columns.map(c => col(c).as(lookup.getOrElse(c, c))): _*)
or withColumnRenamed
:
df.withColumnRenamed("_1", "x1")
which use with foldLeft
to rename multiple columns:
lookup.foldLeft(df)((acc, ca) => acc.withColumnRenamed(ca._1, ca._2))
With nested structures (structs
) one possible option is renaming by selecting a whole structure:
val nested = spark.read.json(sc.parallelize(Seq(
"""{"foobar": {"foo": {"bar": {"first": 1.0, "second": 2.0}}}, "id": 1}"""
)))
nested.printSchema
// root
// |-- foobar: struct (nullable = true)
// | |-- foo: struct (nullable = true)
// | | |-- bar: struct (nullable = true)
// | | | |-- first: double (nullable = true)
// | | | |-- second: double (nullable = true)
// |-- id: long (nullable = true)
@transient val foobarRenamed = struct(
struct(
struct(
$"foobar.foo.bar.first".as("x"), $"foobar.foo.bar.first".as("y")
).alias("point")
).alias("location")
).alias("record")
nested.select(foobarRenamed, $"id").printSchema
// root
// |-- record: struct (nullable = false)
// | |-- location: struct (nullable = false)
// | | |-- point: struct (nullable = false)
// | | | |-- x: double (nullable = true)
// | | | |-- y: double (nullable = true)
// |-- id: long (nullable = true)
Note that it may affect nullability
metadata. Another possibility is to rename by casting:
nested.select($"foobar".cast(
"struct<location:struct<point:struct<x:double,y:double>>>"
).alias("record")).printSchema
// root
// |-- record: struct (nullable = true)
// | |-- location: struct (nullable = true)
// | | |-- point: struct (nullable = true)
// | | | |-- x: double (nullable = true)
// | | | |-- y: double (nullable = true)
or:
import org.apache.spark.sql.types._
nested.select($"foobar".cast(
StructType(Seq(
StructField("location", StructType(Seq(
StructField("point", StructType(Seq(
StructField("x", DoubleType), StructField("y", DoubleType)))))))))
).alias("record")).printSchema
// root
// |-- record: struct (nullable = true)
// | |-- location: struct (nullable = true)
// | | |-- point: struct (nullable = true)
// | | | |-- x: double (nullable = true)
// | | | |-- y: double (nullable = true)
Trying to use Spring Boot REST to Read JSON String from POST
The issue appears with parsing the JSON from request body, tipical for an invalid JSON. If you're using curl on windows, try escaping the json like -d "{"name":"value"}"
or even -d "{"""name""":"value"""}"
On the other hand you can ommit the content-type header in which case whetewer is sent will be converted to your String argument
How to convert a multipart file to File?
You can get the content of a MultipartFile
by using the getBytes
method and you can write to the file using Files.newOutputStream()
:
public void write(MultipartFile file, Path dir) {
Path filepath = Paths.get(dir.toString(), file.getOriginalFilename());
try (OutputStream os = Files.newOutputStream(filepath)) {
os.write(file.getBytes());
}
}
You can also use the transferTo method:
public void multipartFileToFile(
MultipartFile multipart,
Path dir
) throws IOException {
Path filepath = Paths.get(dir.toString(), multipart.getOriginalFilename());
multipart.transferTo(filepath);
}
How to fix "'System.AggregateException' occurred in mscorlib.dll"
The accepted answer will work if you can easily reproduce the issue. However, as a matter of best practice, you should be catching any exceptions (and logging) that are executed within a task. Otherwise, your application will crash if anything unexpected occurs within the task.
Task.Factory.StartNew(x=>
throw new Exception("I didn't account for this");
)
However, if we do this, at least the application does not crash.
Task.Factory.StartNew(x=>
try {
throw new Exception("I didn't account for this");
}
catch(Exception ex) {
//Log ex
}
)
PHP prepend leading zero before single digit number, on-the-fly
You can use sprintf: http://php.net/manual/en/function.sprintf.php
<?php
$num = 4;
$num_padded = sprintf("%02d", $num);
echo $num_padded; // returns 04
?>
It will only add the zero if it's less than the required number of characters.
Edit: As pointed out by @FelipeAls:
When working with numbers, you should use %d
(rather than %s
), especially when there is the potential for negative numbers. If you're only using positive numbers, either option works fine.
For example:
sprintf("%04s", 10);
returns 0010
sprintf("%04s", -10);
returns 0-10
Where as:
sprintf("%04d", 10);
returns 0010
sprintf("%04d", -10);
returns -010
C - Convert an uppercase letter to lowercase
If condition is wrong. Also return type for lower is needed.
#include <stdio.h>
int lower(int a)
{
if ((a >= 65) && (a <= 90))
a = a + 32;
return a;
}
int _tmain(int argc, _TCHAR* argv[])
{
putchar(lower('A'));
return 0;
}
Remove querystring from URL
An easy way to get this is:
function getPathFromUrl(url) {
return url.split("?")[0];
}
For those who also wish to remove the hash (not part of the original question) when no querystring exists, that requires a little bit more:
function stripQueryStringAndHashFromPath(url) {
return url.split("?")[0].split("#")[0];
}
EDIT
@caub (originally @crl) suggested a simpler combo that works for both query string and hash (though it uses RegExp, in case anyone has a problem with that):
function getPathFromUrl(url) {
return url.split(/[?#]/)[0];
}
Python main call within class
Remember, you are NOT allowed to do this.
class foo():
def print_hello(self):
print("Hello") # This next line will produce an ERROR!
self.print_hello() # <---- it calls a class function, inside a class,
# but outside a class function. Not allowed.
You must call a class function from either outside the class, or from within a function in that class.
Validate a username and password against Active Directory?
My Simple Function
private bool IsValidActiveDirectoryUser(string activeDirectoryServerDomain, string username, string password)
{
try
{
DirectoryEntry de = new DirectoryEntry("LDAP://" + activeDirectoryServerDomain, username + "@" + activeDirectoryServerDomain, password, AuthenticationTypes.Secure);
DirectorySearcher ds = new DirectorySearcher(de);
ds.FindOne();
return true;
}
catch //(Exception ex)
{
return false;
}
}
How to use sed/grep to extract text between two words?
You can strip strings in Bash alone:
$ foo="Here is a String"
$ foo=${foo##*Here }
$ echo "$foo"
is a String
$ foo=${foo%% String*}
$ echo "$foo"
is a
$
And if you have a GNU grep that includes PCRE, you can use a zero-width assertion:
$ echo "Here is a String" | grep -Po '(?<=(Here )).*(?= String)'
is a
Android ImageButton with a selected state?
Try this:
<item
android:state_focused="true"
android:state_enabled="true"
android:drawable="@drawable/map_toolbar_details_selected" />
Also for colors i had success with
<selector
xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:state_selected="true"
android:color="@color/primary_color" />
<item
android:color="@color/secondary_color" />
</selector>
Why do I have to run "composer dump-autoload" command to make migrations work in laravel?
OK so I think i know the issue you're having.
Basically, because Composer can't see the migration files you are creating, you are having to run the dump-autoload command which won't download anything new, but looks for all of the classes it needs to include again. It just regenerates the list of all classes that need to be included in the project (autoload_classmap.php), and this is why your migration is working after you run that command.
How to fix it (possibly)
You need to add some extra information to your composer.json file.
"autoload": {
"classmap": [
"PATH TO YOUR MIGRATIONS FOLDER"
],
}
You need to add the path to your migrations folder to the classmap array. Then run the following three commands...
php artisan clear-compiled
composer dump-autoload
php artisan optimize
This will clear the current compiled files, update the classes it needs and then write them back out so you don't have to do it again.
Ideally, you execute composer dump-autoload -o
, for a faster load of your webpages. The only reason it is not default, is because it takes a bit longer to generate (but is only slightly noticable).
Hope you can manage to get this sorted, as its very annoying indeed :(
Run C++ in command prompt - Windows
It depends on what compiler you're using.
For example, if you are using Visual C++ .NET 2010 Express, run Visual C++ 2010 Express Command Prompt from the start menu, and you can simply compile and run the code.
> cl /EHsc mycode.cpp
> mycode.exe
or from the regular command line, you can run vcvars32.bat
first to set up the environment. Alternatively search for setvcvars.cmd
(part of a FLOSS project) and use that to even locate the installed VS and have it call vcvars32.bat
for you.
Please check your compiler's manual for command lines.
How to have css3 animation to loop forever
Whilst Elad's solution will work, you can also do it inline:
-moz-animation: fadeinphoto 7s 20s infinite;
-webkit-animation: fadeinphoto 7s 20s infinite;
-o-animation: fadeinphoto 7s 20s infinite;
animation: fadeinphoto 7s 20s infinite;
How do I pass multiple parameters into a function in PowerShell?
Parameters in calls to functions in PowerShell (all versions) are space-separated, not comma separated. Also, the parentheses are entirely unneccessary and will cause a parse error in PowerShell 2.0 (or later) if Set-StrictMode
-Version 2
or higher is active. Parenthesised arguments are used in .NET methods only.
function foo($a, $b, $c) {
"a: $a; b: $b; c: $c"
}
ps> foo 1 2 3
a: 1; b: 2; c: 3
Map vs Object in JavaScript
This is a short way for me to remember it: KOI
- Keys. Object key is strings or symbols. Map keys can also be numbers (1 and "1" are different), objects,
NaN
, etc. It uses ===
to distinguish between keys, with one exception NaN !== NaN
but you can use NaN
as a key.
- Order. The insertion order is remembered. So
[...map]
or [...map.keys()]
has a particular order.
- Interface. Object:
obj[key]
or obj.a
(in some language, []
and []=
are really part of the interface). Map has get()
, set()
, has()
, delete()
etc. Note that you can use map[123]
but that is using it as a plain JS object.
What is a blob URL and why it is used?
What is blob url? Why it is used?
BLOB is just byte sequence. Browser recognize it as byte stream. It is used to get byte stream from source.
A Blob object represents a file-like object of immutable, raw data. Blobs represent data that isn't necessarily in a JavaScript-native format. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system.
Can i make my own blob url on a server?
Yes you can there are serveral ways to do so for example try http://php.net/manual/en/function.ibase-blob-echo.php
Read more on
How to add click event to a iframe with JQuery
You can solve it very easily, just wrap that iframe in wrapper, and track clicks on it.
Like this:
<div id="iframe_id_wrapper">
<iframe id="iframe_id" src="http://something.com"></iframe>
</div>
And disable pointer events on iframe itself.
#iframe_id { pointer-events: none; }
After this changes your code will work like expected.
$('#iframe_id_wrapper').click(function() {
//run function that records clicks
});
Python Web Crawlers and "getting" html source code
If you are using Python > 3.x
you don't need to install any libraries, this is directly built in the python framework. The old urllib2
package has been renamed to urllib
:
from urllib import request
response = request.urlopen("https://www.google.com")
# set the correct charset below
page_source = response.read().decode('utf-8')
print(page_source)
How can I solve Exception in thread "main" java.lang.NullPointerException error
This is the problem
double a[] = null;
Since a
is null
, NullPointerException
will arise every time you use it until you initialize it. So this:
a[i] = var;
will fail.
A possible solution would be initialize it when declaring it:
double a[] = new double[PUT_A_LENGTH_HERE]; //seems like this constant should be 7
IMO more important than solving this exception, is the fact that you should learn to read the stacktrace and understand what it says, so you could detect the problems and solve it.
java.lang.NullPointerException
This exception means there's a variable with null
value being used. How to solve? Just make sure the variable is not null
before being used.
at twoten.TwoTenB.(TwoTenB.java:29)
This line has two parts:
- First, shows the class and method where the error was thrown. In this case, it was at
<init>
method in class TwoTenB
declared in package twoten
. When you encounter an error message with SomeClassName.<init>
, means the error was thrown while creating a new instance of the class e.g. executing the constructor (in this case that seems to be the problem).
- Secondly, shows the file and line number location where the error is thrown, which is between parenthesis. This way is easier to spot where the error arose. So you have to look into file TwoTenB.java, line number 29. This seems to be
a[i] = var;
.
From this line, other lines will be similar to tell you where the error arose. So when reading this:
at javapractice.JavaPractice.main(JavaPractice.java:32)
It means that you were trying to instantiate a TwoTenB
object reference inside the main
method of your class JavaPractice
declared in javapractice
package.
How to git clone a specific tag
git clone -b 13.1rc1-Gotham --depth 1 https://github.com/xbmc/xbmc.git
Cloning into 'xbmc'...
remote: Counting objects: 17977, done.
remote: Compressing objects: 100% (13473/13473), done.
Receiving objects: 36% (6554/17977), 19.21 MiB | 469 KiB/s
Will be faster than :
git clone https://github.com/xbmc/xbmc.git
Cloning into 'xbmc'...
remote: Reusing existing pack: 281705, done.
remote: Counting objects: 533, done.
remote: Compressing objects: 100% (177/177), done.
Receiving objects: 14% (40643/282238), 55.46 MiB | 578 KiB/s
Or
git clone -b 13.1rc1-Gotham https://github.com/xbmc/xbmc.git
Cloning into 'xbmc'...
remote: Reusing existing pack: 281705, done.
remote: Counting objects: 533, done.
remote: Compressing objects: 100% (177/177), done.
Receiving objects: 12% (34441/282238), 20.25 MiB | 461 KiB/s
Linq order by, group by and order by each group?
Alternatively you can do like this :
var _items = from a in StudentsGrades
group a by a.Name;
foreach (var _itemGroup in _items)
{
foreach (var _item in _itemGroup.OrderBy(a=>a.grade))
{
------------------------
--------------------------
}
}
React - Display loading screen while DOM is rendering?
The most important question is: what do you mean by 'loading'? If you are talking about the physical element being mounted, some of the first answers here are great. However, if the first thing your app does is check for authentication, what you are really loading is data from the backend whether the user passed a cookie that labels them an authorized or unauthorized user.
This is based around redux, but you can do easily change it to plain react state model.
action creator:
export const getTodos = () => {
return async dispatch => {
let res;
try {
res = await axios.get('/todos/get');
dispatch({
type: AUTH,
auth: true
});
dispatch({
type: GET_TODOS,
todos: res.data.todos
});
} catch (e) {
} finally {
dispatch({
type: LOADING,
loading: false
});
}
};
};
The finally part means whether the user is authed or not, the loading screen goes away after a response is received.
Here's what a component that loads it could look like:
class App extends Component {
renderLayout() {
const {
loading,
auth,
username,
error,
handleSidebarClick,
handleCloseModal
} = this.props;
if (loading) {
return <Loading />;
}
return (
...
);
}
...
componentDidMount() {
this.props.getTodos();
}
...
render() {
return this.renderLayout();
}
}
If state.loading is truthy, we will always see a loading screen. On componentDidMount, we call our getTodos function, which is an action creator that turns state.loading falsy when we get a response (which can be an error). Our component updates, calls render again, and this time there is no loading screen because of the if statement.
Bash loop ping successful
You don't need to use echo or grep. You could do this:
ping -oc 100000 8.8.8.8 > /dev/null && say "up" || say "down"
Introducing FOREIGN KEY constraint may cause cycles or multiple cascade paths - why?
I had this issue also, I solved it instantly with this answer from a similar thread
In my case, I didn't want to delete the dependent record on key deletion. If this is the case in your situation just simply change the Boolean value in the migration to false:
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
Chances are, if you are creating relationships which throw this compiler error but DO want to maintain cascade delete; you have an issue with your relationships.
Scanf/Printf double variable C
As far as I read manual pages, scanf says that 'l' length modifier indicates (in case of floating points) that the argument is of type double rather than of type float, so you can have 'lf, le, lg'.
As for printing, officially, the manual says that 'l' applies only to integer types. So it might be not supported on some systems or by some standards. For instance, I get the following error message when compiling with gcc -Wall -Wextra -pedantic
a.c:6:1: warning: ISO C90 does not support the ‘%lf’ gnu_printf format [-Wformat=]
So you may want to doublecheck if your standard supports the syntax.
To conclude, I would say that you read with '%lf' and you print with '%f'.
Why doesn't Git ignore my specified file?
I run into this, it's an old question, but I want that file to be tracked but to not track it on certain working copies, to do that you can run
git update-index --assume-unchanged sites/default/settings.php
How to do a timer in Angular 5
You can simply use setInterval
to create such timer in Angular, Use this Code for timer -
timeLeft: number = 60;
interval;
startTimer() {
this.interval = setInterval(() => {
if(this.timeLeft > 0) {
this.timeLeft--;
} else {
this.timeLeft = 60;
}
},1000)
}
pauseTimer() {
clearInterval(this.interval);
}
<button (click)='startTimer()'>Start Timer</button>
<button (click)='pauseTimer()'>Pause</button>
<p>{{timeLeft}} Seconds Left....</p>
Another way using Observable timer like below -
import { timer } from 'rxjs';
observableTimer() {
const source = timer(1000, 2000);
const abc = source.subscribe(val => {
console.log(val, '-');
this.subscribeTimer = this.timeLeft - val;
});
}
<p (click)="observableTimer()">Start Observable timer</p> {{subscribeTimer}}
Working Example
For more information read here
Order by multiple columns with Doctrine
The orderBy
method requires either two strings or an Expr\OrderBy
object. If you want to add multiple order declarations, the correct thing is to use addOrderBy
method, or instantiate an OrderBy
object and populate it accordingly:
# Inside a Repository method:
$myResults = $this->createQueryBuilder('a')
->addOrderBy('a.column1', 'ASC')
->addOrderBy('a.column2', 'ASC')
->addOrderBy('a.column3', 'DESC')
;
# Or, using a OrderBy object:
$orderBy = new OrderBy('a.column1', 'ASC');
$orderBy->add('a.column2', 'ASC');
$orderBy->add('a.column3', 'DESC');
$myResults = $this->createQueryBuilder('a')
->orderBy($orderBy)
;
Resolve Git merge conflicts in favor of their changes during a pull
You can use the recursive "theirs" strategy option:
git merge --strategy-option theirs
From the man:
ours
This option forces conflicting hunks to be auto-resolved cleanly by
favoring our version. Changes from the other tree that do not
conflict with our side are reflected to the merge result.
This should not be confused with the ours merge strategy, which does
not even look at what the other tree contains at all. It discards
everything the other tree did, declaring our history contains all that
happened in it.
theirs
This is opposite of ours.
Note: as the man page says, the "ours" merge strategy-option is very different from the "ours" merge strategy.
Add a month to a Date
addedMonth <- seq(as.Date('2004-01-01'), length=2, by='1 month')[2]
addedQuarter <- seq(as.Date('2004-01-01'), length=2, by='1 quarter')[2]
Fill Combobox from database
To use the Combobox
in the way you intend, you could pass in an object to the cmbTripName.Items.Add
method.
That object should have FleetID
and FleetName
properties:
while (drd.Read())
{
cmbTripName.Items.Add(new Fleet(drd["FleetID"].ToString(), drd["FleetName"].ToString()));
}
cmbTripName.ValueMember = "FleetId";
cmbTripName.DisplayMember = "FleetName";
The Fleet
Class:
class Fleet
{
public Fleet(string fleetId, string fleetName)
{
FleetId = fleetId;
FleetName = fleetName
}
public string FleetId {get;set;}
public string FleetName {get;set;}
}
Or, You could probably do away with the need for a Fleet
class completely by using an anonymous type...
while (drd.Read())
{
cmbTripName.Items.Add(new {FleetId = drd["FleetID"].ToString(), FleetName = drd["FleetName"].ToString()});
}
cmbTripName.ValueMember = "FleetId";
cmbTripName.DisplayMember = "FleetName";
Python Pandas: Get index of rows which column matches certain value
df.iloc[i]
returns the ith
row of df
. i
does not refer to the index label, i
is a 0-based index.
In contrast, the attribute index
returns actual index labels, not numeric row-indices:
df.index[df['BoolCol'] == True].tolist()
or equivalently,
df.index[df['BoolCol']].tolist()
You can see the difference quite clearly by playing with a DataFrame with
a non-default index that does not equal to the row's numerical position:
df = pd.DataFrame({'BoolCol': [True, False, False, True, True]},
index=[10,20,30,40,50])
In [53]: df
Out[53]:
BoolCol
10 True
20 False
30 False
40 True
50 True
[5 rows x 1 columns]
In [54]: df.index[df['BoolCol']].tolist()
Out[54]: [10, 40, 50]
If you want to use the index,
In [56]: idx = df.index[df['BoolCol']]
In [57]: idx
Out[57]: Int64Index([10, 40, 50], dtype='int64')
then you can select the rows using loc
instead of iloc
:
In [58]: df.loc[idx]
Out[58]:
BoolCol
10 True
40 True
50 True
[3 rows x 1 columns]
Note that loc
can also accept boolean arrays:
In [55]: df.loc[df['BoolCol']]
Out[55]:
BoolCol
10 True
40 True
50 True
[3 rows x 1 columns]
If you have a boolean array, mask
, and need ordinal index values, you can compute them using np.flatnonzero
:
In [110]: np.flatnonzero(df['BoolCol'])
Out[112]: array([0, 3, 4])
Use df.iloc
to select rows by ordinal index:
In [113]: df.iloc[np.flatnonzero(df['BoolCol'])]
Out[113]:
BoolCol
10 True
40 True
50 True
List all liquibase sql types
This is a comprehensive list of all liquibase datatypes and how they are converted for different databases:
boolean
MySQLDatabase: BIT(1)
SQLiteDatabase: BOOLEAN
H2Database: BOOLEAN
PostgresDatabase: BOOLEAN
UnsupportedDatabase: BOOLEAN
DB2Database: SMALLINT
MSSQLDatabase: [bit]
OracleDatabase: NUMBER(1)
HsqlDatabase: BOOLEAN
FirebirdDatabase: SMALLINT
DerbyDatabase: SMALLINT
InformixDatabase: BOOLEAN
SybaseDatabase: BIT
SybaseASADatabase: BIT
tinyint
MySQLDatabase: TINYINT
SQLiteDatabase: TINYINT
H2Database: TINYINT
PostgresDatabase: SMALLINT
UnsupportedDatabase: TINYINT
DB2Database: SMALLINT
MSSQLDatabase: [tinyint]
OracleDatabase: NUMBER(3)
HsqlDatabase: TINYINT
FirebirdDatabase: SMALLINT
DerbyDatabase: SMALLINT
InformixDatabase: TINYINT
SybaseDatabase: TINYINT
SybaseASADatabase: TINYINT
int
MySQLDatabase: INT
SQLiteDatabase: INTEGER
H2Database: INT
PostgresDatabase: INT
UnsupportedDatabase: INT
DB2Database: INTEGER
MSSQLDatabase: [int]
OracleDatabase: INTEGER
HsqlDatabase: INT
FirebirdDatabase: INT
DerbyDatabase: INTEGER
InformixDatabase: INT
SybaseDatabase: INT
SybaseASADatabase: INT
mediumint
MySQLDatabase: MEDIUMINT
SQLiteDatabase: MEDIUMINT
H2Database: MEDIUMINT
PostgresDatabase: MEDIUMINT
UnsupportedDatabase: MEDIUMINT
DB2Database: MEDIUMINT
MSSQLDatabase: [int]
OracleDatabase: MEDIUMINT
HsqlDatabase: MEDIUMINT
FirebirdDatabase: MEDIUMINT
DerbyDatabase: MEDIUMINT
InformixDatabase: MEDIUMINT
SybaseDatabase: MEDIUMINT
SybaseASADatabase: MEDIUMINT
bigint
MySQLDatabase: BIGINT
SQLiteDatabase: BIGINT
H2Database: BIGINT
PostgresDatabase: BIGINT
UnsupportedDatabase: BIGINT
DB2Database: BIGINT
MSSQLDatabase: [bigint]
OracleDatabase: NUMBER(38, 0)
HsqlDatabase: BIGINT
FirebirdDatabase: BIGINT
DerbyDatabase: BIGINT
InformixDatabase: INT8
SybaseDatabase: BIGINT
SybaseASADatabase: BIGINT
float
MySQLDatabase: FLOAT
SQLiteDatabase: FLOAT
H2Database: FLOAT
PostgresDatabase: FLOAT
UnsupportedDatabase: FLOAT
DB2Database: FLOAT
MSSQLDatabase: [float](53)
OracleDatabase: FLOAT
HsqlDatabase: FLOAT
FirebirdDatabase: FLOAT
DerbyDatabase: FLOAT
InformixDatabase: FLOAT
SybaseDatabase: FLOAT
SybaseASADatabase: FLOAT
double
MySQLDatabase: DOUBLE
SQLiteDatabase: DOUBLE
H2Database: DOUBLE
PostgresDatabase: DOUBLE PRECISION
UnsupportedDatabase: DOUBLE
DB2Database: DOUBLE
MSSQLDatabase: [float](53)
OracleDatabase: FLOAT(24)
HsqlDatabase: DOUBLE
FirebirdDatabase: DOUBLE PRECISION
DerbyDatabase: DOUBLE
InformixDatabase: DOUBLE PRECISION
SybaseDatabase: DOUBLE
SybaseASADatabase: DOUBLE
decimal
MySQLDatabase: DECIMAL
SQLiteDatabase: DECIMAL
H2Database: DECIMAL
PostgresDatabase: DECIMAL
UnsupportedDatabase: DECIMAL
DB2Database: DECIMAL
MSSQLDatabase: [decimal](18, 0)
OracleDatabase: DECIMAL
HsqlDatabase: DECIMAL
FirebirdDatabase: DECIMAL
DerbyDatabase: DECIMAL
InformixDatabase: DECIMAL
SybaseDatabase: DECIMAL
SybaseASADatabase: DECIMAL
number
MySQLDatabase: numeric
SQLiteDatabase: NUMBER
H2Database: NUMBER
PostgresDatabase: numeric
UnsupportedDatabase: NUMBER
DB2Database: numeric
MSSQLDatabase: [numeric](18, 0)
OracleDatabase: NUMBER
HsqlDatabase: numeric
FirebirdDatabase: numeric
DerbyDatabase: numeric
InformixDatabase: numeric
SybaseDatabase: numeric
SybaseASADatabase: numeric
blob
MySQLDatabase: LONGBLOB
SQLiteDatabase: BLOB
H2Database: BLOB
PostgresDatabase: BYTEA
UnsupportedDatabase: BLOB
DB2Database: BLOB
MSSQLDatabase: [varbinary](MAX)
OracleDatabase: BLOB
HsqlDatabase: BLOB
FirebirdDatabase: BLOB
DerbyDatabase: BLOB
InformixDatabase: BLOB
SybaseDatabase: IMAGE
SybaseASADatabase: LONG BINARY
function
MySQLDatabase: FUNCTION
SQLiteDatabase: FUNCTION
H2Database: FUNCTION
PostgresDatabase: FUNCTION
UnsupportedDatabase: FUNCTION
DB2Database: FUNCTION
MSSQLDatabase: [function]
OracleDatabase: FUNCTION
HsqlDatabase: FUNCTION
FirebirdDatabase: FUNCTION
DerbyDatabase: FUNCTION
InformixDatabase: FUNCTION
SybaseDatabase: FUNCTION
SybaseASADatabase: FUNCTION
UNKNOWN
MySQLDatabase: UNKNOWN
SQLiteDatabase: UNKNOWN
H2Database: UNKNOWN
PostgresDatabase: UNKNOWN
UnsupportedDatabase: UNKNOWN
DB2Database: UNKNOWN
MSSQLDatabase: [UNKNOWN]
OracleDatabase: UNKNOWN
HsqlDatabase: UNKNOWN
FirebirdDatabase: UNKNOWN
DerbyDatabase: UNKNOWN
InformixDatabase: UNKNOWN
SybaseDatabase: UNKNOWN
SybaseASADatabase: UNKNOWN
datetime
MySQLDatabase: datetime
SQLiteDatabase: TEXT
H2Database: TIMESTAMP
PostgresDatabase: TIMESTAMP WITHOUT TIME ZONE
UnsupportedDatabase: datetime
DB2Database: TIMESTAMP
MSSQLDatabase: [datetime]
OracleDatabase: TIMESTAMP
HsqlDatabase: TIMESTAMP
FirebirdDatabase: TIMESTAMP
DerbyDatabase: TIMESTAMP
InformixDatabase: DATETIME YEAR TO FRACTION(5)
SybaseDatabase: datetime
SybaseASADatabase: datetime
time
MySQLDatabase: time
SQLiteDatabase: time
H2Database: time
PostgresDatabase: TIME WITHOUT TIME ZONE
UnsupportedDatabase: time
DB2Database: time
MSSQLDatabase: [time](7)
OracleDatabase: DATE
HsqlDatabase: time
FirebirdDatabase: time
DerbyDatabase: time
InformixDatabase: INTERVAL HOUR TO FRACTION(5)
SybaseDatabase: time
SybaseASADatabase: time
timestamp
MySQLDatabase: timestamp
SQLiteDatabase: TEXT
H2Database: TIMESTAMP
PostgresDatabase: TIMESTAMP WITHOUT TIME ZONE
UnsupportedDatabase: timestamp
DB2Database: timestamp
MSSQLDatabase: [datetime]
OracleDatabase: TIMESTAMP
HsqlDatabase: TIMESTAMP
FirebirdDatabase: TIMESTAMP
DerbyDatabase: TIMESTAMP
InformixDatabase: DATETIME YEAR TO FRACTION(5)
SybaseDatabase: datetime
SybaseASADatabase: timestamp
date
MySQLDatabase: date
SQLiteDatabase: date
H2Database: date
PostgresDatabase: date
UnsupportedDatabase: date
DB2Database: date
MSSQLDatabase: [date]
OracleDatabase: date
HsqlDatabase: date
FirebirdDatabase: date
DerbyDatabase: date
InformixDatabase: date
SybaseDatabase: date
SybaseASADatabase: date
char
MySQLDatabase: CHAR
SQLiteDatabase: CHAR
H2Database: CHAR
PostgresDatabase: CHAR
UnsupportedDatabase: CHAR
DB2Database: CHAR
MSSQLDatabase: [char](1)
OracleDatabase: CHAR
HsqlDatabase: CHAR
FirebirdDatabase: CHAR
DerbyDatabase: CHAR
InformixDatabase: CHAR
SybaseDatabase: CHAR
SybaseASADatabase: CHAR
varchar
MySQLDatabase: VARCHAR
SQLiteDatabase: VARCHAR
H2Database: VARCHAR
PostgresDatabase: VARCHAR
UnsupportedDatabase: VARCHAR
DB2Database: VARCHAR
MSSQLDatabase: [varchar](1)
OracleDatabase: VARCHAR2
HsqlDatabase: VARCHAR
FirebirdDatabase: VARCHAR
DerbyDatabase: VARCHAR
InformixDatabase: VARCHAR
SybaseDatabase: VARCHAR
SybaseASADatabase: VARCHAR
nchar
MySQLDatabase: NCHAR
SQLiteDatabase: NCHAR
H2Database: NCHAR
PostgresDatabase: NCHAR
UnsupportedDatabase: NCHAR
DB2Database: NCHAR
MSSQLDatabase: [nchar](1)
OracleDatabase: NCHAR
HsqlDatabase: CHAR
FirebirdDatabase: NCHAR
DerbyDatabase: NCHAR
InformixDatabase: NCHAR
SybaseDatabase: NCHAR
SybaseASADatabase: NCHAR
nvarchar
MySQLDatabase: NVARCHAR
SQLiteDatabase: NVARCHAR
H2Database: NVARCHAR
PostgresDatabase: VARCHAR
UnsupportedDatabase: NVARCHAR
DB2Database: NVARCHAR
MSSQLDatabase: [nvarchar](1)
OracleDatabase: NVARCHAR2
HsqlDatabase: VARCHAR
FirebirdDatabase: NVARCHAR
DerbyDatabase: VARCHAR
InformixDatabase: NVARCHAR
SybaseDatabase: NVARCHAR
SybaseASADatabase: NVARCHAR
clob
MySQLDatabase: LONGTEXT
SQLiteDatabase: TEXT
H2Database: CLOB
PostgresDatabase: TEXT
UnsupportedDatabase: CLOB
DB2Database: CLOB
MSSQLDatabase: [varchar](MAX)
OracleDatabase: CLOB
HsqlDatabase: CLOB
FirebirdDatabase: BLOB SUB_TYPE TEXT
DerbyDatabase: CLOB
InformixDatabase: CLOB
SybaseDatabase: TEXT
SybaseASADatabase: LONG VARCHAR
currency
MySQLDatabase: DECIMAL
SQLiteDatabase: REAL
H2Database: DECIMAL
PostgresDatabase: DECIMAL
UnsupportedDatabase: DECIMAL
DB2Database: DECIMAL(19, 4)
MSSQLDatabase: [money]
OracleDatabase: NUMBER(15, 2)
HsqlDatabase: DECIMAL
FirebirdDatabase: DECIMAL(18, 4)
DerbyDatabase: DECIMAL
InformixDatabase: MONEY
SybaseDatabase: MONEY
SybaseASADatabase: MONEY
uuid
MySQLDatabase: char(36)
SQLiteDatabase: TEXT
H2Database: UUID
PostgresDatabase: UUID
UnsupportedDatabase: char(36)
DB2Database: char(36)
MSSQLDatabase: [uniqueidentifier]
OracleDatabase: RAW(16)
HsqlDatabase: char(36)
FirebirdDatabase: char(36)
DerbyDatabase: char(36)
InformixDatabase: char(36)
SybaseDatabase: UNIQUEIDENTIFIER
SybaseASADatabase: UNIQUEIDENTIFIER
For reference, this is the groovy script I've used to generate this output:
@Grab('org.liquibase:liquibase-core:3.5.1')
import liquibase.database.core.*
import liquibase.datatype.core.*
def datatypes = [BooleanType,TinyIntType,IntType,MediumIntType,BigIntType,FloatType,DoubleType,DecimalType,NumberType,BlobType,DatabaseFunctionType,UnknownType,DateTimeType,TimeType,TimestampType,DateType,CharType,VarcharType,NCharType,NVarcharType,ClobType,CurrencyType,UUIDType]
def databases = [MySQLDatabase, SQLiteDatabase, H2Database, PostgresDatabase, UnsupportedDatabase, DB2Database, MSSQLDatabase, OracleDatabase, HsqlDatabase, FirebirdDatabase, DerbyDatabase, InformixDatabase, SybaseDatabase, SybaseASADatabase]
datatypes.each {
def datatype = it.newInstance()
datatype.finishInitialization("")
println datatype.name
databases.each { println "$it.simpleName: ${datatype.toDatabaseDataType(it.newInstance())}"}
println ''
}
How to pass an array into a function, and return the results with an array
Try
$waffles = foo($waffles);
Or pass the array by reference, like suggested in the other answers.
In addition, you can add new elements to an array without writing the index, e.g.
$waffles = array(1,2,3); // filling on initialization
or
$waffles = array();
$waffles[] = 1;
$waffles[] = 2;
$waffles[] = 3;
On a sidenote, if you want to sum all values in an array, use array_sum()
How do I create batch file to rename large number of files in a folder?
you can do this easily without manual editing or using fancy text editors. Here's a vbscript.
Set objFS = CreateObject("Scripting.FileSystemObject")
strFolder="c:\test"
Set objFolder = objFS.GetFolder(strFolder)
For Each strFile In objFolder.Files
If objFS.GetExtensionName(strFile) = "jpg" Then
strFileName = strFile.Name
If InStr(strFileName,"Vacation2010") > 0 Then
strNewFileName = Replace(strFileName,"Vacation2010","December")
strFile.Name = strNewFileName
End If
End If
Next
save as myscript.vbs and
C:\test> cscript //nologo myscript.vbs
Add new row to excel Table (VBA)
As using ListRow.Add
can be a huge bottle neck, we should only use it if it can’t be avoided.
If performance is important to you, use this function here to resize the table, which is quite faster than adding rows the recommended way.
Be aware that this will overwrite data below your table if there is any!
This function is based on the accepted answer of Chris Neilsen
Public Sub AddRowToTable(ByRef tableName As String, ByRef data As Variant)
Dim tableLO As ListObject
Dim tableRange As Range
Dim newRow As Range
Set tableLO = Range(tableName).ListObject
tableLO.AutoFilter.ShowAllData
If (tableLO.ListRows.Count = 0) Then
Set newRow = tableLO.ListRows.Add(AlwaysInsert:=True).Range
Else
Set tableRange = tableLO.Range
tableLO.Resize tableRange.Resize(tableRange.Rows.Count + 1, tableRange.Columns.Count)
Set newRow = tableLO.ListRows(tableLO.ListRows.Count).Range
End If
If TypeName(data) = "Range" Then
newRow = data.Value
Else
newRow = data
End If
End Sub
'printf' with leading zeros in C
Your format specifier is incorrect. From the printf()
man page on my machine:
0
A zero '0
' character indicating that zero-padding should be used rather than blank-padding. A '-
' overrides a '0
' if both are used;
Field Width:
An optional digit string specifying a field width; if the output string has fewer characters than the field width it will be blank-padded on the left (or right, if the left-adjustment indicator has been given) to make up the field width (note that a leading zero is a flag, but an embedded zero is part of a field width);
Precision: An optional period, '.
', followed by an optional digit string giving a precision which specifies the number of digits to appear after the decimal point, for e and f formats, or the maximum number of characters to be printed from a string; if the digit string is missing, the precision is treated as zero;
For your case, your format would be %09.3f
:
#include <stdio.h>
int main(int argc, char **argv)
{
printf("%09.3f\n", 4917.24);
return 0;
}
Output:
$ make testapp
cc testapp.c -o testapp
$ ./testapp
04917.240
Note that this answer is conditional on your embedded system having a printf()
implementation that is standard-compliant for these details - many embedded environments do not have such an implementation.
How to list all databases in the mongo shell?
From the command line issue
mongo --quiet --eval "printjson(db.adminCommand('listDatabases'))"
which gives output
{
"databases" : [
{
"name" : "admin",
"sizeOnDisk" : 978944,
"empty" : false
},
{
"name" : "local",
"sizeOnDisk" : 77824,
"empty" : false
},
{
"name" : "meteor",
"sizeOnDisk" : 778240,
"empty" : false
}
],
"totalSize" : 1835008,
"ok" : 1
}
What is the difference between the kernel space and the user space?
The Random Access Memory (RAM) can be logically divided into two distinct regions namely - the kernel space and the user space.(The Physical Addresses of the RAM are not actually divided only the Virtual Addresses, all this implemented by the MMU)
The kernel runs in the part of memory entitled to it. This part of memory cannot be accessed directly by the processes of the normal users, while as the kernel can access all parts of the memory. To access some part of the kernel, the user processes have to use the predefined system calls i.e. open
, read
, write
etc. Also, the C
library functions like printf
call the system call write
in turn.
The system calls act as an interface between the user processes and the kernel processes. The access rights are placed on the kernel space in order to stop the users from messing up with the kernel, unknowingly.
So, when a system call occurs, a software interrupt is sent to the kernel. The CPU may hand over the control temporarily to the associated interrupt handler routine. The kernel process which was halted by the interrupt resumes after the interrupt handler routine finishes its job.
How to create a MySQL hierarchical recursive query?
Based on the @trincot answer, very good explained, I use WITH RECURSIVE ()
statement to create a breadcrumb using id
of the current page and go backwards in the hierarchy to find the every parent
in my route
table.
So, the @trincot solution is adapted here in the opposite direction to find parents instead of descendants.
I also added depth
value which is usefull to invert result order (otherwise the breadcrumb would be upside down).
WITH RECURSIVE cte (
`id`,
`title`,
`url`,
`icon`,
`class`,
`parent_id`,
`depth`
) AS (
SELECT
`id`,
`title`,
`url`,
`icon`,
`class`,
`parent_id`,
1 AS `depth`
FROM `route`
WHERE `id` = :id
UNION ALL
SELECT
P.`id`,
P.`title`,
P.`url`,
P.`icon`,
P.`class`,
P.`parent_id`,
`depth` + 1
FROM `route` P
INNER JOIN cte
ON P.`id` = cte.`parent_id`
)
SELECT * FROM cte ORDER BY `depth` DESC;
Before upgrade to mySQL 8+, I was using vars but it's deprecated and no more working on my 8.0.22 version !
EDIT 2021-02-19 :
Example for hierarchical menu
After @david comment I decided to try to make a full hierarchical menu with all nodes and sorted as I want (with sorting
column which sort items in each depth). Very usefull for my user/authorization matrix page.
This really simplifies my old version with one query on each depth (PHP loops).
This example intergrates an INNER JOIN with url
table to filter route by website (multi-websites CMS system).
You can see the essential path
column that contains CONCAT()
function to sort the menu in the right way.
SELECT R.* FROM (
WITH RECURSIVE cte (
`id`,
`title`,
`url`,
`icon`,
`class`,
`parent`,
`depth`,
`sorting`,
`path`
) AS (
SELECT
`id`,
`title`,
`url`,
`icon`,
`class`,
`parent`,
1 AS `depth`,
`sorting`,
CONCAT(`sorting`, ' ' , `title`) AS `path`
FROM `route`
WHERE `parent` = 0
UNION ALL SELECT
D.`id`,
D.`title`,
D.`url`,
D.`icon`,
D.`class`,
D.`parent`,
`depth` + 1,
D.`sorting`,
CONCAT(cte.`path`, ' > ', D.`sorting`, ' ' , D.`title`)
FROM `route` D
INNER JOIN cte
ON cte.`id` = D.`parent`
)
SELECT * FROM cte
) R
INNER JOIN `url` U
ON R.`id` = U.`route_id`
AND U.`site_id` = 1
ORDER BY `path` ASC
How to recover the deleted files using "rm -R" command in linux server?
since answers are disappointing I would like suggest a way in which I got deleted stuff back.
I use an ide to code and accidently I used rm -rf from terminal to remove complete folder. Thanks to ide I recoved it back by reverting the change from ide's local history.
(my ide is intelliJ but all ide's support history backup)
How to convert IPython notebooks to PDF and HTML?
I combined some answers above in inline python that u can add to ~/.bashrc or ~/.zshrc to compile and convert many notebooks to a single pdf file
function convert_notebooks(){
# read anything on this folder that ends on ipynb and run pdf formatting for it
python -c 'import os; [os.system("jupyter nbconvert --to pdf " + f) for f in os.listdir (".") if f.endswith("ipynb")]'
# to convert to pdf u must have installed latex and that means u have pdfjam installed
pdfjam *
}
TextView - setting the text size programmatically doesn't seem to work
Currently, setTextSize(float size)
method will work well so we don't need to use another method for change text size
android.widget.TextView.java source code
/**
* Set the default text size to the given value, interpreted as "scaled
* pixel" units. This size is adjusted based on the current density and
* user font size preference.
*
* <p>Note: if this TextView has the auto-size feature enabled than this function is no-op.
*
* @param size The scaled pixel size.
*
* @attr ref android.R.styleable#TextView_textSize
*/
@android.view.RemotableViewMethod
public void setTextSize(float size) {
setTextSize(TypedValue.COMPLEX_UNIT_SP, size);
}
Example using
textView.setTextSize(20); // set your text size = 20sp
How to check if a string contains a specific text
You can use strpos()
or stripos()
to check if the string contain the given needle. It will return the position where it was found, otherwise will return FALSE.
Use the operators ===
or `!== to differ FALSE from 0 in PHP.
How to force deletion of a python object?
- Add an exit handler that closes all the bars.
__del__()
gets called when the number of references to an object hits 0 while the VM is still running. This may be caused by the GC.
- If
__init__()
raises an exception then the object is assumed to be incomplete and __del__()
won't be invoked.
Strip / trim all strings of a dataframe
Money Shot
Here's a compact version of using applymap
with a straightforward lambda expression to call strip
only when the value is of a string type:
df.applymap(lambda x: x.strip() if isinstance(x, str) else x)
Full Example
A more complete example:
import pandas as pd
def trim_all_columns(df):
"""
Trim whitespace from ends of each value across all series in dataframe
"""
trim_strings = lambda x: x.strip() if isinstance(x, str) else x
return df.applymap(trim_strings)
# simple example of trimming whitespace from data elements
df = pd.DataFrame([[' a ', 10], [' c ', 5]])
df = trim_all_columns(df)
print(df)
>>>
0 1
0 a 10
1 c 5
Working Example
Here's a working example hosted by trinket:
https://trinket.io/python3/e6ab7fb4ab
Convert number of minutes into hours & minutes using PHP
Sorry for bringing up an old topic, but I used some code from one of these answers a lot, and today I told myself I could do it without stealing someone's code. I was surprised how easy it was. What I wanted is 510 minutes to be return as 08:30, so this is what the code does.
function tm($nm, $lZ = true){ //tm = to military (time), lZ = leading zero (if true it returns 510 as 08:30, if false 8:30
$mins = $nm % 60;
if($mins == 0) $mins = "0$mins"; //adds a zero, so it doesn't return 08:0, but 08:00
$hour = floor($nm / 60);
if($lZ){
if($hour < 10) return "0$hour:$mins";
}
return "$hour:$mins";
}
I use short variable names because I'm going to use the function a lot, and I'm lazy.
Python: get key of index in dictionary
Python dictionaries have a key and a value, what you are asking for is what key(s) point to a given value.
You can only do this in a loop:
[k for (k, v) in i.iteritems() if v == 0]
Note that there can be more than one key per value in a dict; {'a': 0, 'b': 0}
is perfectly legal.
If you want ordering you either need to use a list or a OrderedDict instance instead:
items = ['a', 'b', 'c']
items.index('a') # gives 0
items[0] # gives 'a'
How do you serialize a model instance in Django?
.values()
is what I needed to convert a model instance to JSON.
.values() documentation: https://docs.djangoproject.com/en/3.0/ref/models/querysets/#values
Example usage with a model called Project.
Note: I'm using Django Rest Framework
@csrf_exempt
@api_view(["GET"])
def get_project(request):
id = request.query_params['id']
data = Project.objects.filter(id=id).values()
if len(data) == 0:
return JsonResponse(status=404, data={'message': 'Project with id {} not found.'.format(id)})
return JsonResponse(data[0])
Result from a valid id:
{
"id": 47,
"title": "Project Name",
"description": "",
"created_at": "2020-01-21T18:13:49.693Z",
}
Java: how to use UrlConnection to post request with authorization?
I ran into this problem today and none of the solutions posted here worked. However, the code posted here worked for a POST request:
// HTTP POST request
private void sendPost() throws Exception {
String url = "https://selfsolve.apple.com/wcResults.do";
URL obj = new URL(url);
HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();
//add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("User-Agent", USER_AGENT);
con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345";
// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
//print result
System.out.println(response.toString());
}
It turns out that it's not the authorization that's the problem. In my case, it was an encoding problem. The content-type I needed was application/json but from the Java documentation:
static String encode(String s, String enc)
Translates a string into application/x-www-form-urlencoded format using a specific encoding scheme.
The encode function translates the string into application/x-www-form-urlencoded.
Now if you don't set a Content-Type, you may get a 415 Unsupported Media Type error. If you set it to application/json or anything that's not application/x-www-form-urlencoded, you get an IOException. To solve this, simply avoid the encode method.
For this particular scenario, the following should work:
String data = "product[title]=" + title +
"&product[content]=" + content +
"&product[price]=" + price.toString() +
"&tags=" + tags;
Another small piece of information that might be helpful as to why the code breaks when creating the buffered reader is because the POST request actually only gets executed when conn.getInputStream() is called.
Jenkins Git Plugin: How to build specific tag?
I set the Advanced->Refspec field to refs/tags/[your tag name]
. This seems simpler than the various other suggestions for Refspec, but it worked just fine for me.
UPDATE 23/7/2014 - Actually, after further testing, it turns out this didn't work as expected. It appears that the HEAD version was still being checked out. Please undo this as the accepted answer. I ended up getting a working solution by following the post from gotgenes in this thread (30th March). The issue mentioned in that post of unnecessary triggering of builds was not an issue for me, as my job is triggered from an upstream job, not from polling SCM.
UPDATE APR-2018 - Note in the comments that this does work for one person, and agrees with Jenkins documentation.
Using Django time/date widgets in custom form
The growing complexity of this answer over time, and the many hacks required, probably ought to caution you against doing this at all. It's relying on undocumented internal implementation details of the admin, is likely to break again in future versions of Django, and is no easier to implement than just finding another JS calendar widget and using that.
That said, here's what you have to do if you're determined to make this work:
Define your own ModelForm subclass for your model (best to put it in forms.py in your app), and tell it to use the AdminDateWidget / AdminTimeWidget / AdminSplitDateTime (replace 'mydate' etc with the proper field names from your model):
from django import forms
from my_app.models import Product
from django.contrib.admin import widgets
class ProductForm(forms.ModelForm):
class Meta:
model = Product
def __init__(self, *args, **kwargs):
super(ProductForm, self).__init__(*args, **kwargs)
self.fields['mydate'].widget = widgets.AdminDateWidget()
self.fields['mytime'].widget = widgets.AdminTimeWidget()
self.fields['mydatetime'].widget = widgets.AdminSplitDateTime()
Change your URLconf to pass 'form_class': ProductForm instead of 'model': Product to the generic create_object view (that'll mean "from my_app.forms import ProductForm" instead of "from my_app.models import Product", of course).
In the head of your template, include {{ form.media }} to output the links to the Javascript files.
And the hacky part: the admin date/time widgets presume that the i18n JS stuff has been loaded, and also require core.js, but don't provide either one automatically. So in your template above {{ form.media }} you'll need:
<script type="text/javascript" src="/my_admin/jsi18n/"></script>
<script type="text/javascript" src="/media/admin/js/core.js"></script>
You may also wish to use the following admin CSS (thanks Alex for mentioning this):
<link rel="stylesheet" type="text/css" href="/media/admin/css/forms.css"/>
<link rel="stylesheet" type="text/css" href="/media/admin/css/base.css"/>
<link rel="stylesheet" type="text/css" href="/media/admin/css/global.css"/>
<link rel="stylesheet" type="text/css" href="/media/admin/css/widgets.css"/>
This implies that Django's admin media (ADMIN_MEDIA_PREFIX) is at /media/admin/ - you can change that for your setup. Ideally you'd use a context processor to pass this values to your template instead of hardcoding it, but that's beyond the scope of this question.
This also requires that the URL /my_admin/jsi18n/ be manually wired up to the django.views.i18n.javascript_catalog view (or null_javascript_catalog if you aren't using I18N). You have to do this yourself instead of going through the admin application so it's accessible regardless of whether you're logged into the admin (thanks Jeremy for pointing this out). Sample code for your URLconf:
(r'^my_admin/jsi18n', 'django.views.i18n.javascript_catalog'),
Lastly, if you are using Django 1.2 or later, you need some additional code in your template to help the widgets find their media:
{% load adminmedia %} /* At the top of the template. */
/* In the head section of the template. */
<script type="text/javascript">
window.__admin_media_prefix__ = "{% filter escapejs %}{% admin_media_prefix %}{% endfilter %}";
</script>
Thanks lupefiasco for this addition.
MySQL - Rows to Columns
My solution :
select h.hostid, sum(ifnull(h.A,0)) as A, sum(ifnull(h.B,0)) as B, sum(ifnull(h.C,0)) as C from (
select
hostid,
case when itemName = 'A' then itemvalue end as A,
case when itemName = 'B' then itemvalue end as B,
case when itemName = 'C' then itemvalue end as C
from history
) h group by hostid
It produces the expected results in the submitted case.
Service Temporarily Unavailable Magento?
You need to follow these steps:
- Go to magento root directory via cPanel/FTP
- In case of Magento1, you will find maintenance.flag and delete it
- In case of Magento2, delete var/maintenance.flag
Using Spring MVC Test to unit test multipart POST request
If you are using Spring4/SpringBoot 1.x, then it's worth mentioning that you can add "text" (json) parts as well . This can be done via MockMvcRequestBuilders.fileUpload().file(MockMultipartFile file) (which is needed as method .multipart()
is not available in this version):
@Test
public void test() throws Exception {
mockMvc.perform(
MockMvcRequestBuilders.fileUpload("/files")
// file-part
.file(makeMultipartFile( "file-part" "some/path/to/file.bin", "application/octet-stream"))
// text part
.file(makeMultipartTextPart("json-part", "{ \"foo\" : \"bar\" }", "application/json"))
.andExpect(status().isOk())));
}
private MockMultipartFile(String requestPartName, String filename,
String contentType, String pathOnClassPath) {
return new MockMultipartFile(requestPartName, filename,
contentType, readResourceFile(pathOnClasspath);
}
// make text-part using MockMultipartFile
private MockMultipartFile makeMultipartTextPart(String requestPartName,
String value, String contentType) throws Exception {
return new MockMultipartFile(requestPartName, "", contentType,
value.getBytes(Charset.forName("UTF-8")));
}
private byte[] readResourceFile(String pathOnClassPath) throws Exception {
return Files.readAllBytes(Paths.get(Thread.currentThread().getContextClassLoader()
.getResource(pathOnClassPath).toUri()));
}
}
How to Right-align flex item?
If you want to use flexbox for this, you should be able to, by doing this (display: flex
on the container, flex: 1
on the items, and text-align: right
on .c
):
.main { display: flex; }
.a, .b, .c {
background: #efefef;
border: 1px solid #999;
flex: 1;
}
.b { text-align: center; }
.c { text-align: right; }
...or alternatively (even simpler), if the items don't need to meet, you can use justify-content: space-between
on the container and remove the text-align
rules completely:
.main { display: flex; justify-content: space-between; }
.a, .b, .c { background: #efefef; border: 1px solid #999; }
Here's a demo on Codepen to allow you to quickly try the above.
What command shows all of the topics and offsets of partitions in Kafka?
You might want to try kt. It's also quite faster than the bundled kafka-topics
.
This is the current most complete info description you can get out of a topic with kt:
kt topic -brokers localhost:9092 -filter my_topic_name -partitions -leaders -replicas
It also outputs as JSON, so you can pipe it to jq
for further flexibility.
How to easily initialize a list of Tuples?
Yes! This is possible.
The { } syntax of the collection initializer works on any IEnumerable
type which has an Add method with the correct amount of arguments.
Without bothering how that works under the covers, that means you can
simply extend from List<T>, add a custom Add method to initialize your
T, and you are done!
public class TupleList<T1, T2> : List<Tuple<T1, T2>>
{
public void Add( T1 item, T2 item2 )
{
Add( new Tuple<T1, T2>( item, item2 ) );
}
}
This allows you to do the following:
var groceryList = new TupleList<int, string>
{
{ 1, "kiwi" },
{ 5, "apples" },
{ 3, "potatoes" },
{ 1, "tomato" }
};
Saving an Object (Data persistence)
You could use the pickle
module in the standard library.
Here's an elementary application of it to your example:
import pickle
class Company(object):
def __init__(self, name, value):
self.name = name
self.value = value
with open('company_data.pkl', 'wb') as output:
company1 = Company('banana', 40)
pickle.dump(company1, output, pickle.HIGHEST_PROTOCOL)
company2 = Company('spam', 42)
pickle.dump(company2, output, pickle.HIGHEST_PROTOCOL)
del company1
del company2
with open('company_data.pkl', 'rb') as input:
company1 = pickle.load(input)
print(company1.name) # -> banana
print(company1.value) # -> 40
company2 = pickle.load(input)
print(company2.name) # -> spam
print(company2.value) # -> 42
You could also define your own simple utility like the following which opens a file and writes a single object to it:
def save_object(obj, filename):
with open(filename, 'wb') as output: # Overwrites any existing file.
pickle.dump(obj, output, pickle.HIGHEST_PROTOCOL)
# sample usage
save_object(company1, 'company1.pkl')
Update
Since this is such a popular answer, I'd like touch on a few slightly advanced usage topics.
cPickle
(or _pickle
) vs pickle
It's almost always preferable to actually use the cPickle
module rather than pickle
because the former is written in C and is much faster. There are some subtle differences between them, but in most situations they're equivalent and the C version will provide greatly superior performance. Switching to it couldn't be easier, just change the import
statement to this:
import cPickle as pickle
In Python 3, cPickle
was renamed _pickle
, but doing this is no longer necessary since the pickle
module now does it automatically—see What difference between pickle and _pickle in python 3?.
The rundown is you could use something like the following to ensure that your code will always use the C version when it's available in both Python 2 and 3:
try:
import cPickle as pickle
except ModuleNotFoundError:
import pickle
Data stream formats (protocols)
pickle
can read and write files in several different, Python-specific, formats, called protocols as described in the documentation, "Protocol version 0" is ASCII and therefore "human-readable". Versions > 0 are binary and the highest one available depends on what version of Python is being used. The default also depends on Python version. In Python 2 the default was Protocol version 0
, but in Python 3.8.1, it's Protocol version 4
. In Python 3.x the module had a pickle.DEFAULT_PROTOCOL
added to it, but that doesn't exist in Python 2.
Fortunately there's shorthand for writing pickle.HIGHEST_PROTOCOL
in every call (assuming that's what you want, and you usually do), just use the literal number -1
— similar to referencing the last element of a sequence via a negative index.
So, instead of writing:
pickle.dump(obj, output, pickle.HIGHEST_PROTOCOL)
You can just write:
pickle.dump(obj, output, -1)
Either way, you'd only have specify the protocol once if you created a Pickler
object for use in multiple pickle operations:
pickler = pickle.Pickler(output, -1)
pickler.dump(obj1)
pickler.dump(obj2)
etc...
Note: If you're in an environment running different versions of Python, then you'll probably want to explicitly use (i.e. hardcode) a specific protocol number that all of them can read (later versions can generally read files produced by earlier ones).
Multiple Objects
While a pickle file can contain any number of pickled objects, as shown in the above samples, when there's an unknown number of them, it's often easier to store them all in some sort of variably-sized container, like a list
, tuple
, or dict
and write them all to the file in a single call:
tech_companies = [
Company('Apple', 114.18), Company('Google', 908.60), Company('Microsoft', 69.18)
]
save_object(tech_companies, 'tech_companies.pkl')
and restore the list and everything in it later with:
with open('tech_companies.pkl', 'rb') as input:
tech_companies = pickle.load(input)
The major advantage is you don't need to know how many object instances are saved in order to load them back later (although doing so without that information is possible, it requires some slightly specialized code). See the answers to the related question Saving and loading multiple objects in pickle file? for details on different ways to do this. Personally I like @Lutz Prechelt's answer the best. Here's it adapted to the examples here:
class Company:
def __init__(self, name, value):
self.name = name
self.value = value
def pickled_items(filename):
""" Unpickle a file of pickled data. """
with open(filename, "rb") as f:
while True:
try:
yield pickle.load(f)
except EOFError:
break
print('Companies in pickle file:')
for company in pickled_items('company_data.pkl'):
print(' name: {}, value: {}'.format(company.name, company.value))
How to get some values from a JSON string in C#?
Following code is working for me.
Usings:
using System.IO;
using System.Net;
using Newtonsoft.Json.Linq;
Code:
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
using (Stream responseStream = response.GetResponseStream())
{
using (StreamReader responseReader = new StreamReader(responseStream))
{
string json = responseReader.ReadToEnd();
string data = JObject.Parse(json)["id"].ToString();
}
}
}
//json = {"kind": "ALL", "id": "1221455", "longUrl": "NewURL"}
Does return stop a loop?
Yes, return
stops execution and exits the function. return
always** exits its function immediately, with no further execution if it's inside a for loop.
It is easily verified for yourself:
_x000D_
_x000D_
function returnMe() {
for (var i = 0; i < 2; i++) {
if (i === 1) return i;
}
}
console.log(returnMe());
_x000D_
_x000D_
_x000D_
** Notes: See this other answer about the special case of try/catch/finally
and this answer about how forEach loops has its own function scope will not break out of the containing function.
Find all zero-byte files in directory and subdirectories
To print the names of all files in and below $dir of size 0:
find "$dir" -size 0
Note that not all implementations of find
will produce output by default, so you may need to do:
find "$dir" -size 0 -print
Two comments on the final loop in the question:
Rather than iterating over every other word in a string and seeing if the alternate values are zero, you can partially eliminate the issue you're having with whitespace by iterating over lines. eg:
printf '1 f1\n0 f 2\n10 f3\n' | while read size path; do
test "$size" -eq 0 && echo "$path"; done
Note that this will fail in your case if any of the paths output by ls contain newlines, and this reinforces 2 points: don't parse ls
, and have a sane naming policy that doesn't allow whitespace in paths.
Secondly, to output the data from the loop, there is no need to store the output in a variable just to echo
it. If you simply let the loop write its output to stdout, you accomplish the same thing but avoid storing it.
How to animate a View with Translate Animation in Android
In order to move a View anywhere on the screen, I would recommend placing it in a full screen layout. By doing so, you won't have to worry about clippings or relative coordinates.
You can try this sample code:
main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" android:id="@+id/rootLayout">
<Button
android:id="@+id/btn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="MOVE" android:layout_centerHorizontal="true"/>
<ImageView
android:id="@+id/img1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" android:layout_marginLeft="10dip"/>
<ImageView
android:id="@+id/img2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" android:layout_centerVertical="true" android:layout_alignParentRight="true"/>
<ImageView
android:id="@+id/img3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" android:layout_marginLeft="60dip" android:layout_alignParentBottom="true" android:layout_marginBottom="100dip"/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" android:clipChildren="false" android:clipToPadding="false">
<ImageView
android:id="@+id/img4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_launcher" android:layout_marginLeft="60dip" android:layout_marginTop="150dip"/>
</LinearLayout>
</RelativeLayout>
Your activity
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
((Button) findViewById( R.id.btn1 )).setOnClickListener( new OnClickListener()
{
@Override
public void onClick(View v)
{
ImageView img = (ImageView) findViewById( R.id.img1 );
moveViewToScreenCenter( img );
img = (ImageView) findViewById( R.id.img2 );
moveViewToScreenCenter( img );
img = (ImageView) findViewById( R.id.img3 );
moveViewToScreenCenter( img );
img = (ImageView) findViewById( R.id.img4 );
moveViewToScreenCenter( img );
}
});
}
private void moveViewToScreenCenter( View view )
{
RelativeLayout root = (RelativeLayout) findViewById( R.id.rootLayout );
DisplayMetrics dm = new DisplayMetrics();
this.getWindowManager().getDefaultDisplay().getMetrics( dm );
int statusBarOffset = dm.heightPixels - root.getMeasuredHeight();
int originalPos[] = new int[2];
view.getLocationOnScreen( originalPos );
int xDest = dm.widthPixels/2;
xDest -= (view.getMeasuredWidth()/2);
int yDest = dm.heightPixels/2 - (view.getMeasuredHeight()/2) - statusBarOffset;
TranslateAnimation anim = new TranslateAnimation( 0, xDest - originalPos[0] , 0, yDest - originalPos[1] );
anim.setDuration(1000);
anim.setFillAfter( true );
view.startAnimation(anim);
}
The method moveViewToScreenCenter
gets the View's absolute coordinates and calculates how much distance has to move from its current position to reach the center of the screen. The statusBarOffset
variable measures the status bar height.
I hope you can keep going with this example. Remember that after the animation your view's position is still the initial one. If you tap the MOVE button again and again the same movement will repeat. If you want to change your view's position do it after the animation is finished.
get current url in twig template?
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) %}
The app
global view variable contains all sorts of useful shortcuts, such as app.session
and app.security.token.user
, that reference the services you might use in a controller.
JPA 2.0, Criteria API, Subqueries, In Expressions
Below is the pseudo-code for using sub-query using Criteria API.
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Object> criteriaQuery = criteriaBuilder.createQuery();
Root<EMPLOYEE> from = criteriaQuery.from(EMPLOYEE.class);
Path<Object> path = from.get("compare_field"); // field to map with sub-query
from.fetch("name");
from.fetch("id");
CriteriaQuery<Object> select = criteriaQuery.select(from);
Subquery<PROJECT> subquery = criteriaQuery.subquery(PROJECT.class);
Root fromProject = subquery.from(PROJECT.class);
subquery.select(fromProject.get("requiredColumnName")); // field to map with main-query
subquery.where(criteriaBuilder.and(criteriaBuilder.equal("name",name_value),criteriaBuilder.equal("id",id_value)));
select.where(criteriaBuilder.in(path).value(subquery));
TypedQuery<Object> typedQuery = entityManager.createQuery(select);
List<Object> resultList = typedQuery.getResultList();
Also it definitely needs some modification as I have tried to map it according to your query. Here is a link http://www.ibm.com/developerworks/java/library/j-typesafejpa/ which explains concept nicely.
How to display JavaScript variables in a HTML page without document.write
Element.innerHTML
is pretty much the way to go. Here are a few ways to use it:
HTML
<div class="results"></div>
JavaScript
// 'Modern' browsers (IE8+, use CSS-style selectors)
document.querySelector('.results').innerHTML = 'Hello World!';
// Using the jQuery library
$('.results').html('Hello World!');
If you just want to update a portion of a <div>
I usually just add an empty element with a class like value
or one I want to replace the contents of to the main <div>
. e.g.
<div class="content">Hello <span class='value'></span></div>
Then I'd use some code like this:
// 'Modern' browsers (IE8+, use CSS-style selectors)
document.querySelector('.content .value').innerHTML = 'World!';
// Using the jQuery library
$(".content .value").html("World!");
Then the HTML/DOM would now contain:
<div class="content">Hello <span class='value'>World!</span></div>
Full example. Click run snippet to try it out.
_x000D_
_x000D_
// Plain Javascript Example_x000D_
var $jsName = document.querySelector('.name');_x000D_
var $jsValue = document.querySelector('.jsValue');_x000D_
_x000D_
$jsName.addEventListener('input', function(event){_x000D_
$jsValue.innerHTML = $jsName.value;_x000D_
}, false);_x000D_
_x000D_
_x000D_
// JQuery example_x000D_
var $jqName = $('.name');_x000D_
var $jqValue = $('.jqValue');_x000D_
_x000D_
$jqName.on('input', function(event){_x000D_
$jqValue.html($jqName.val());_x000D_
});
_x000D_
html {_x000D_
font-family: sans-serif;_x000D_
font-size: 16px;_x000D_
}_x000D_
_x000D_
h1 {_x000D_
margin: 1em 0 0.25em 0;_x000D_
}_x000D_
_x000D_
input[type=text] {_x000D_
padding: 0.5em;_x000D_
}_x000D_
_x000D_
.jsValue, .jqValue {_x000D_
color: red;_x000D_
}
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<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
<script src="https://code.jquery.com/jquery-1.11.3.js"></script>_x000D_
<meta charset="utf-8">_x000D_
<meta name="viewport" content="width=device-width">_x000D_
<title>Setting HTML content example</title>_x000D_
</head>_x000D_
<body>_x000D_
<!-- This <input> field is where I'm getting the name from -->_x000D_
<label>Enter your name: <input class="name" type="text" value="World"/></label>_x000D_
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<!-- Plain Javascript Example -->_x000D_
<h1>Plain Javascript Example</h1>Hello <span class="jsValue">World</span>_x000D_
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<!-- jQuery Example -->_x000D_
<h1>jQuery Example</h1>Hello <span class="jqValue">World</span>_x000D_
</body>_x000D_
</html>
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How to get request url in a jQuery $.get/ajax request
I can't get it to work on $.get()
because it has no complete
event.
I suggest to use $.ajax()
like this,
$.ajax({
url: 'http://www.example.org',
data: {'a':1,'b':2,'c':3},
dataType: 'xml',
complete : function(){
alert(this.url)
},
success: function(xml){
}
});
How to maintain a Unique List in Java?
You could just use a HashSet<String>
to maintain a collection of unique objects. If the Integer
values in your map are important, then you can instead use the containsKey
method of maps to test whether your key is already in the map.
Retrieving subfolders names in S3 bucket from boto3
S3 is an object storage, it doesn't have real directory structure. The "/" is rather cosmetic.
One reason that people want to have a directory structure, because they can maintain/prune/add a tree to the application. For S3, you treat such structure as sort of index or search tag.
To manipulate object in S3, you need boto3.client or boto3.resource, e.g.
To list all object
import boto3
s3 = boto3.client("s3")
all_objects = s3.list_objects(Bucket = 'bucket-name')
http://boto3.readthedocs.org/en/latest/reference/services/s3.html#S3.Client.list_objects
In fact, if the s3 object name is stored using '/' separator. The more recent version of list_objects (list_objects_v2) allows you to limit the response to keys that begin with the specified prefix.
To limit the items to items under certain sub-folders:
import boto3
s3 = boto3.client("s3")
response = s3.list_objects_v2(
Bucket=BUCKET,
Prefix ='DIR1/DIR2',
MaxKeys=100 )
Documentation
Another option is using python os.path function to extract the folder prefix. Problem is that this will require listing objects from undesired directories.
import os
s3_key = 'first-level/1456753904534/part-00014'
filename = os.path.basename(s3_key)
foldername = os.path.dirname(s3_key)
# if you are not using conventional delimiter like '#'
s3_key = 'first-level#1456753904534#part-00014
filename = s3_key.split("#")[-1]
A reminder about boto3 : boto3.resource is a nice high level API. There are pros and cons using boto3.client vs boto3.resource. If you develop internal shared library, using boto3.resource will give you a blackbox layer over the resources used.
Iterating through all the cells in Excel VBA or VSTO 2005
In Excel VBA, this function will give you the content of any cell in any worksheet.
Function getCellContent(Byref ws As Worksheet, ByVal rowindex As Integer, ByVal colindex As Integer) as String
getCellContent = CStr(ws.Cells(rowindex, colindex))
End Function
So if you want to check the value of cells, just put the function in a loop, give it the reference to the worksheet you want and the row index and column index of the cell. Row index and column index both start from 1, meaning that cell A1 will be ws.Cells(1,1) and so on.
How to get only the date value from a Windows Forms DateTimePicker control?
Following that this question has been already given a good answer, in WinForms we can also set a Custom Format to the DateTimePicker Format property as Vivek said, this allow us to display the date/time in the specified format string within the DateTimePicker, then, it will be simple just as we do to get text from a TextBox.
// Set the Format type and the CustomFormat string.
dateTimePicker1.Format = DateTimePickerFormat.Custom;
dateTimePicker1.CustomFormat = "yyyy/MM/dd";
We are now able to get Date only easily by getting the Text from the DateTimePicker:
MessageBox.Show("Selected Date: " + dateTimePicker1.Text, "DateTimePicker", MessageBoxButtons.OK, MessageBoxIcon.Information);
NOTE: If you are planning to insert Date only data to a date column type in SQL, see this documentation related to the supported String Literal Formats for date. You can not insert a date in the format string ydm because is not supported:
dateTimePicker1.CustomFormat = "yyyy/dd/MM";
var qr = "INSERT INTO tbl VALUES (@dtp)";
using (var insertCommand = new SqlCommand..
{
try
{
insertCommand.Parameters.AddWithValue("@dtp", dateTimePicker1.Text);
con.Open();
insertCommand.ExecuteScalar();
}
catch (Exception ex)
{
MessageBox.Show("Exception message: " + ex.Message, "DateTimePicker", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
the above code ends in the following Exception:
Be aware. Cheers.
How to automatically import data from uploaded CSV or XLS file into Google Sheets
You can programmatically import data from a csv file in your Drive into an existing Google Sheet using Google Apps Script, replacing/appending data as needed.
Below is some sample code. It assumes that: a) you have a designated folder in your Drive where the CSV file is saved/uploaded to; b) the CSV file is named "report.csv" and the data in it comma-delimited; and c) the CSV data is imported into a designated spreadsheet. See comments in code for further details.
function importData() {
var fSource = DriveApp.getFolderById(reports_folder_id); // reports_folder_id = id of folder where csv reports are saved
var fi = fSource.getFilesByName('report.csv'); // latest report file
var ss = SpreadsheetApp.openById(data_sheet_id); // data_sheet_id = id of spreadsheet that holds the data to be updated with new report data
if ( fi.hasNext() ) { // proceed if "report.csv" file exists in the reports folder
var file = fi.next();
var csv = file.getBlob().getDataAsString();
var csvData = CSVToArray(csv); // see below for CSVToArray function
var newsheet = ss.insertSheet('NEWDATA'); // create a 'NEWDATA' sheet to store imported data
// loop through csv data array and insert (append) as rows into 'NEWDATA' sheet
for ( var i=0, lenCsv=csvData.length; i<lenCsv; i++ ) {
newsheet.getRange(i+1, 1, 1, csvData[i].length).setValues(new Array(csvData[i]));
}
/*
** report data is now in 'NEWDATA' sheet in the spreadsheet - process it as needed,
** then delete 'NEWDATA' sheet using ss.deleteSheet(newsheet)
*/
// rename the report.csv file so it is not processed on next scheduled run
file.setName("report-"+(new Date().toString())+".csv");
}
};
// http://www.bennadel.com/blog/1504-Ask-Ben-Parsing-CSV-Strings-With-Javascript-Exec-Regular-Expression-Command.htm
// This will parse a delimited string into an array of
// arrays. The default delimiter is the comma, but this
// can be overriden in the second argument.
function CSVToArray( strData, strDelimiter ) {
// Check to see if the delimiter is defined. If not,
// then default to COMMA.
strDelimiter = (strDelimiter || ",");
// Create a regular expression to parse the CSV values.
var objPattern = new RegExp(
(
// Delimiters.
"(\\" + strDelimiter + "|\\r?\\n|\\r|^)" +
// Quoted fields.
"(?:\"([^\"]*(?:\"\"[^\"]*)*)\"|" +
// Standard fields.
"([^\"\\" + strDelimiter + "\\r\\n]*))"
),
"gi"
);
// Create an array to hold our data. Give the array
// a default empty first row.
var arrData = [[]];
// Create an array to hold our individual pattern
// matching groups.
var arrMatches = null;
// Keep looping over the regular expression matches
// until we can no longer find a match.
while (arrMatches = objPattern.exec( strData )){
// Get the delimiter that was found.
var strMatchedDelimiter = arrMatches[ 1 ];
// Check to see if the given delimiter has a length
// (is not the start of string) and if it matches
// field delimiter. If id does not, then we know
// that this delimiter is a row delimiter.
if (
strMatchedDelimiter.length &&
(strMatchedDelimiter != strDelimiter)
){
// Since we have reached a new row of data,
// add an empty row to our data array.
arrData.push( [] );
}
// Now that we have our delimiter out of the way,
// let's check to see which kind of value we
// captured (quoted or unquoted).
if (arrMatches[ 2 ]){
// We found a quoted value. When we capture
// this value, unescape any double quotes.
var strMatchedValue = arrMatches[ 2 ].replace(
new RegExp( "\"\"", "g" ),
"\""
);
} else {
// We found a non-quoted value.
var strMatchedValue = arrMatches[ 3 ];
}
// Now that we have our value string, let's add
// it to the data array.
arrData[ arrData.length - 1 ].push( strMatchedValue );
}
// Return the parsed data.
return( arrData );
};
You can then create time-driven trigger in your script project to run importData()
function on a regular basis (e.g. every night at 1AM), so all you have to do is put new report.csv file into the designated Drive folder, and it will be automatically processed on next scheduled run.
If you absolutely MUST work with Excel files instead of CSV, then you can use this code below. For it to work you must enable Drive API in Advanced Google Services in your script and in Developers Console (see How to Enable Advanced Services for details).
/**
* Convert Excel file to Sheets
* @param {Blob} excelFile The Excel file blob data; Required
* @param {String} filename File name on uploading drive; Required
* @param {Array} arrParents Array of folder ids to put converted file in; Optional, will default to Drive root folder
* @return {Spreadsheet} Converted Google Spreadsheet instance
**/
function convertExcel2Sheets(excelFile, filename, arrParents) {
var parents = arrParents || []; // check if optional arrParents argument was provided, default to empty array if not
if ( !parents.isArray ) parents = []; // make sure parents is an array, reset to empty array if not
// Parameters for Drive API Simple Upload request (see https://developers.google.com/drive/web/manage-uploads#simple)
var uploadParams = {
method:'post',
contentType: 'application/vnd.ms-excel', // works for both .xls and .xlsx files
contentLength: excelFile.getBytes().length,
headers: {'Authorization': 'Bearer ' + ScriptApp.getOAuthToken()},
payload: excelFile.getBytes()
};
// Upload file to Drive root folder and convert to Sheets
var uploadResponse = UrlFetchApp.fetch('https://www.googleapis.com/upload/drive/v2/files/?uploadType=media&convert=true', uploadParams);
// Parse upload&convert response data (need this to be able to get id of converted sheet)
var fileDataResponse = JSON.parse(uploadResponse.getContentText());
// Create payload (body) data for updating converted file's name and parent folder(s)
var payloadData = {
title: filename,
parents: []
};
if ( parents.length ) { // Add provided parent folder(s) id(s) to payloadData, if any
for ( var i=0; i<parents.length; i++ ) {
try {
var folder = DriveApp.getFolderById(parents[i]); // check that this folder id exists in drive and user can write to it
payloadData.parents.push({id: parents[i]});
}
catch(e){} // fail silently if no such folder id exists in Drive
}
}
// Parameters for Drive API File Update request (see https://developers.google.com/drive/v2/reference/files/update)
var updateParams = {
method:'put',
headers: {'Authorization': 'Bearer ' + ScriptApp.getOAuthToken()},
contentType: 'application/json',
payload: JSON.stringify(payloadData)
};
// Update metadata (filename and parent folder(s)) of converted sheet
UrlFetchApp.fetch('https://www.googleapis.com/drive/v2/files/'+fileDataResponse.id, updateParams);
return SpreadsheetApp.openById(fileDataResponse.id);
}
/**
* Sample use of convertExcel2Sheets() for testing
**/
function testConvertExcel2Sheets() {
var xlsId = "0B9**************OFE"; // ID of Excel file to convert
var xlsFile = DriveApp.getFileById(xlsId); // File instance of Excel file
var xlsBlob = xlsFile.getBlob(); // Blob source of Excel file for conversion
var xlsFilename = xlsFile.getName(); // File name to give to converted file; defaults to same as source file
var destFolders = []; // array of IDs of Drive folders to put converted file in; empty array = root folder
var ss = convertExcel2Sheets(xlsBlob, xlsFilename, destFolders);
Logger.log(ss.getId());
}
The above code is also available as a gist here.
Add a new line to the end of a JtextArea
When you want to create a new line or wrap in your TextArea you have to add \n (newline) after the text.
TextArea t = new TextArea();
t.setText("insert text when you want a new line add \nThen more text....);
setBounds();
setFont();
add(t);
This is the only way I was able to do it, maybe there is a simpler way but I havent discovered that yet.
Official reasons for "Software caused connection abort: socket write error"
I have seen this most often when a corporate firewall on a workstation/laptop gets in the way, it kills the connection.
eg. I have a server process and a client process on the same machine. The server is listening on all interfaces (0.0.0.0) and the client attempts a connection to the public/home interface (note not the loopback interface 127.0.0.1).
If the machine is has its network disconnected (eg wifi turned off) then the connection is formed. If the machine is connected to the corporate network (directly or vpn) then the connection is formed.
However, if the machine is connected to a public wifi (or home network) then the firewall kicks in an kills the connection. In this situation connecting the client to the loopback interface works fine, just not to the home/public interface.
Hope this helps.
127 Return code from $?
Generally it means:
127 - command not found
but it can also mean that the command is found,
but a library that is required by the command is NOT found.
What are the RGB codes for the Conditional Formatting 'Styles' in Excel?
The easiest way to do this is to format a cell the way you want it, then use the "cell format ..." contextual menu to get to the fill and format colours, use the "more colors ..." button to get to the hexagon colour selector, select the custom tab.
The RGB colours are as in the table at the bottom of the pane. If you prefer HSL values change the color model from RGB to HSL. I have used this to change the saturation on my bad cells. A higher luminosity gives a worse results and the shade of all the cells is the same just the deepness of the colour is modified.
HttpURLConnection timeout settings
If the HTTP Connection doesn't timeout, You can implement the timeout checker in the background thread itself (AsyncTask, Service, etc), the following class is an example for Customize AsyncTask which timeout after certain period
public abstract class AsyncTaskWithTimer<Params, Progress, Result> extends
AsyncTask<Params, Progress, Result> {
private static final int HTTP_REQUEST_TIMEOUT = 30000;
@Override
protected Result doInBackground(Params... params) {
createTimeoutListener();
return doInBackgroundImpl(params);
}
private void createTimeoutListener() {
Thread timeout = new Thread() {
public void run() {
Looper.prepare();
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (AsyncTaskWithTimer.this != null
&& AsyncTaskWithTimer.this.getStatus() != Status.FINISHED)
AsyncTaskWithTimer.this.cancel(true);
handler.removeCallbacks(this);
Looper.myLooper().quit();
}
}, HTTP_REQUEST_TIMEOUT);
Looper.loop();
}
};
timeout.start();
}
abstract protected Result doInBackgroundImpl(Params... params);
}
A Sample for this
public class AsyncTaskWithTimerSample extends AsyncTaskWithTimer<Void, Void, Void> {
@Override
protected void onCancelled(Void void) {
Log.d(TAG, "Async Task onCancelled With Result");
super.onCancelled(result);
}
@Override
protected void onCancelled() {
Log.d(TAG, "Async Task onCancelled");
super.onCancelled();
}
@Override
protected Void doInBackgroundImpl(Void... params) {
// Do background work
return null;
};
}
Variable not accessible when initialized outside function
To define a global variable which is based off a DOM element a few things must be checked. First, if the code is in the <head>
section, then the DOM will not loaded on execution. In this case, an event handler must be placed in order to set the variable after the DOM has been loaded, like this:
var systemStatus;
window.onload = function(){ systemStatus = document.getElementById("system_status"); };
However, if this script is inline in the page as the DOM loads, then it can be done as long as the DOM element in question has loaded above where the script is located. This is because javascript executes synchronously. This would be valid:
<div id="system_status"></div>
<script type="text/javascript">
var systemStatus = document.getElementById("system_status");
</script>
As a result of the latter example, most pages which run scripts in the body save them until the very end of the document. This will allow the page to load, and then the javascript to execute which in most cases causes a visually faster rendering of the DOM.
A good Sorted List for Java
What about using a HashMap
? Insertion, deletion, and retrieval are all O(1) operations. If you wanted to sort everything, you could grab a List of the values in the Map and run them through an O(n log n) sorting algorithm.
edit
A quick search has found LinkedHashMap, which maintains insertion order of your keys. It's not an exact solution, but it's pretty close.
Disable browser cache for entire ASP.NET website
You may want to disable browser caching for all pages rendered by controllers (i.e. HTML pages), but keep caching in place for resources such as scripts, style sheets, and images. If you're using MVC4+ bundling and minification, you'll want to keep the default cache durations for scripts and stylesheets (very long durations, since the cache gets invalidated based on a change to a unique URL, not based on time).
In MVC4+, to disable browser caching across all controllers, but retain it for anything not served by a controller, add this to FilterConfig.RegisterGlobalFilters
:
filters.Add(new DisableCache());
Define DisableCache
as follows:
class DisableCache : ActionFilterAttribute
{
public override void OnResultExecuting(ResultExecutingContext filterContext)
{
filterContext.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
}
}
How to exclude 0 from MIN formula Excel
Solutions listed did not exactly work for me. The closest was Chief Wiggum - I wanted to add a comment on his answer but lack the reputation to do so. So I post as separate answer:
=MIN(IF(A1:E1>0;A1:E1))
Then instead of pressing ENTER, press CTRL+SHIFT+ENTER and watch Excel add {
and }
to respectively the beginning and the end of the formula (to activate the formula on array).
The comma "," and "If" statement as proposed by Chief Wiggum did not work on Excel Home and Student 2013. Need a semicolon ";" as well as full cap "IF" did the trick. Small syntax difference but took me 1.5 hour to figure out why I was getting an error and #VALUE.
How do I call one constructor from another in Java?
Within a constructor, you can use the this
keyword to invoke another constructor in the same class. Doing so is called an explicit constructor invocation.
Here's another Rectangle class, with a different implementation from the one in the Objects section.
public class Rectangle {
private int x, y;
private int width, height;
public Rectangle() {
this(1, 1);
}
public Rectangle(int width, int height) {
this( 0,0,width, height);
}
public Rectangle(int x, int y, int width, int height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
}
This class contains a set of constructors. Each constructor initializes some or all of the rectangle's member variables.
BASH Syntax error near unexpected token 'done'
I have exactly the same issue as above, and took me the whole day to discover that it doesn't like my newline approach. Instead I reused the same code with semi-colon approach instead.
For example my initial code using the newline (which threw the same error as yours):
Y=1
while test "$Y" -le "20"
do
echo "Number $Y"
Y=$[Y+1]
done
And using code with semicolon approach with worked wonder:
Y=1 ; while test "$Y" -le "20"; do echo "Number $Y"; Y=$[Y+1] ; done
I notice the same problem occurs for other commands as well using the newline approach, so I think I am gonna stick to using semicolon for my future code.
Show or hide element in React
var Search= React.createClass({
getInitialState: () => { showResults: false },
onClick: () => this.setState({ showResults: true }),
render: function () {
const { showResults } = this.state;
return (
<div className="date-range">
<input type="submit" value="Search" onClick={this.handleClick} />
{showResults && <Results />}
</div>
);
}
});
var Results = React.createClass({
render: function () {
return (
<div id="results" className="search-results">
Some Results
</div>
);
}
});
React.renderComponent(<Search /> , document.body);
How do I center an anchor element in CSS?
I think you can't do that with inline elements like anchor, span. But to make it work you have to set the display to block.
<a href="http://www.example.com" style="text-align:center;display:block;">example</a>
Ship an application with a database
If you are using ROOM there is a pretty straight forward path already https://developer.android.com/training/data-storage/room/prepopulate in the official documentation.
Here's how it is in action to repopulate your database from an asset file:
Room.databaseBuilder(appContext, AppDatabase.class, "Sample.db")
.createFromAsset("database/myapp.db")
.build()
or from a file:
Room.databaseBuilder(appContext, AppDatabase.class, "Sample.db")
.createFromFile(File("mypath"))
.build()
and if you are not using Room, I strongly recommend you do
How to style the menu items on an Android action bar
My guess is that you have to also style the views that are generated from the menu information in your onCreateOptionsMenu(). The styling you applied so far is working, but I doubt that the menu items, when rendered with text use a style that is the same as the title part of the ActionBar.
You may want to look at Menu.getActionView() to get the view for the menu action and then adjust it accordingly.
Reset C int array to zero : the fastest way?
memset
(from <string.h>
) is probably the fastest standard way, since it's usually a routine written directly in assembly and optimized by hand.
memset(myarray, 0, sizeof(myarray)); // for automatically-allocated arrays
memset(myarray, 0, N*sizeof(*myarray)); // for heap-allocated arrays, where N is the number of elements
By the way, in C++ the idiomatic way would be to use std::fill
(from <algorithm>
):
std::fill(myarray, myarray+N, 0);
which may be optimized automatically into a memset
; I'm quite sure that it will work as fast as memset
for int
s, while it may perform slightly worse for smaller types if the optimizer isn't smart enough. Still, when in doubt, profile.
White spaces are required between publicId and systemId
If you're working from some network that requires you to use a proxy in your browser to connect to the internet (likely an office building), that might be it. I had the same issue and adding the proxy configs to the network settings solved it.
- Go to your preferences (Eclipse -> Preferences on a Mac, or Window -> Preferences on a Windows)
- Then -> General -> expand to view the list underneath -> Select Network Connections (don't expand)
- At the top of the page that appears there is a drop down, select "Manual."
- Then select "HTTP" in the list directly below the drop down (which now should have all it's options checked) and then click the "Edit" button to the right of the list.
- Enter in the proxy url and port you need to connect to the internet in your web browser normally.
- Repeat for "HTTPS."
If you don't know the proxy url and port, talk to your network admin.
javascript: calculate x% of a number
This is what I would do:
// num is your number
// amount is your percentage
function per(num, amount){
return num*amount/100;
}
...
<html goes here>
...
alert(per(10000, 35.8));
How to declare a variable in a PostgreSQL query
I accomplished the same goal by using a WITH
clause, it's nowhere near as elegant but can do the same thing. Though for this example it's really overkill. I also don't particularly recommend this.
WITH myconstants (var1, var2) as (
values (5, 'foo')
)
SELECT *
FROM somewhere, myconstants
WHERE something = var1
OR something_else = var2;
Cut Corners using CSS
by small modification of Joshep's code...You can use this code which seems like right corner folded down as per your requirement.
div {
height: 300px;
background: red;
position: relative;
}
div:before {
content: '';
position: absolute;
top: 0; right: 0;
border-top: 80px solid white;
border-left: 80px solid blue;
width: 0;
}
allowing only alphabets in text box using java script
You can use HTML5 pattern attribute to do this:
<form>
<input type='text' pattern='[A-Za-z\\s]*'/>
</form>
If the user enters an input that conflicts with the pattern, it will show an error dialogue automatically.
3 column layout HTML/CSS
Something like this should do it:
.column-left{ float: left; width: 33.333%; }
.column-right{ float: right; width: 33.333%; }
.column-center{ display: inline-block; width: 33.333%; }
DEMO
EDIT
To do this with a larger number of columns you could build a very simple grid system. For example, something like this should work for a five column layout:
_x000D_
_x000D_
.column {_x000D_
float: left;_x000D_
position: relative;_x000D_
width: 20%;_x000D_
_x000D_
/*for demo purposes only */_x000D_
background: #f2f2f2;_x000D_
border: 1px solid #e6e6e6;_x000D_
box-sizing: border-box;_x000D_
}_x000D_
_x000D_
.column-offset-1 {_x000D_
left: 20%;_x000D_
}_x000D_
.column-offset-2 {_x000D_
left: 40%;_x000D_
}_x000D_
.column-offset-3 {_x000D_
left: 60%;_x000D_
}_x000D_
.column-offset-4 {_x000D_
left: 80%;_x000D_
}_x000D_
_x000D_
.column-inset-1 {_x000D_
left: -20%;_x000D_
}_x000D_
.column-inset-2 {_x000D_
left: -40%;_x000D_
}_x000D_
.column-inset-3 {_x000D_
left: -60%;_x000D_
}_x000D_
.column-inset-4 {_x000D_
left: -80%;_x000D_
}
_x000D_
<div class="container">_x000D_
<div class="column column-one column-offset-2">Column one</div>_x000D_
<div class="column column-two column-inset-1">Column two</div>_x000D_
<div class="column column-three column-offset-1">Column three</div>_x000D_
<div class="column column-four column-inset-2">Column four</div>_x000D_
<div class="column column-five">Column five</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_
Or, if you are lucky enough to be able to support only modern browsers, you can use flexible boxes:
_x000D_
_x000D_
.container {_x000D_
display: flex;_x000D_
}_x000D_
_x000D_
.column {_x000D_
flex: 1;_x000D_
_x000D_
/*for demo purposes only */_x000D_
background: #f2f2f2;_x000D_
border: 1px solid #e6e6e6;_x000D_
box-sizing: border-box;_x000D_
}_x000D_
_x000D_
.column-one {_x000D_
order: 3;_x000D_
}_x000D_
.column-two {_x000D_
order: 1;_x000D_
}_x000D_
.column-three {_x000D_
order: 4;_x000D_
}_x000D_
.column-four {_x000D_
order: 2;_x000D_
}_x000D_
.column-five {_x000D_
order: 5;_x000D_
}
_x000D_
<div class="container">_x000D_
<div class="column column-one">Column one</div>_x000D_
<div class="column column-two">Column two</div>_x000D_
<div class="column column-three">Column three</div>_x000D_
<div class="column column-four">Column four</div>_x000D_
<div class="column column-five">Column five</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_
How to install crontab on Centos
As seen in Install crontab on CentOS, the crontab package in CentOS is vixie-cron
. Hence, do install it with:
yum install vixie-cron
And then start it with:
service crond start
To make it persistent, so that it starts on boot, use:
chkconfig crond on
On CentOS 7 you need to use cronie
:
yum install cronie
On CentOS 6 you can install vixie-cron
, but the real package is cronie
:
yum install vixie-cron
and
yum install cronie
In both cases you get the same output:
.../...
==================================================================
Package Arch Version Repository Size
==================================================================
Installing:
cronie x86_64 1.4.4-12.el6 base 73 k
Installing for dependencies:
cronie-anacron x86_64 1.4.4-12.el6 base 30 k
crontabs noarch 1.10-33.el6 base 10 k
exim x86_64 4.72-6.el6 epel 1.2 M
Transaction Summary
==================================================================
Install 4 Package(s)
How to set child process' environment variable in Makefile
I only needed the environment variables locally to invoke my test command, here's an example setting multiple environment vars in a bash shell, and escaping the dollar sign in make
.
SHELL := /bin/bash
.PHONY: test tests
test tests:
PATH=./node_modules/.bin/:$$PATH \
JSCOVERAGE=1 \
nodeunit tests/
Where is svn.exe in my machine?
First off, if subversion installed on your machine? if not look at what server your tortoisesvn is setup to connect to.
the default location when subversion is installed is c:\program files\subversion
you can find svn.exe in c:\program files\subversion\bin where you can run your cmd line actions.
jQuery posting valid json in request body
An actual JSON request would look like this:
data: '{"command":"on"}',
Where you're sending an actual JSON string. For a more general solution, use JSON.stringify()
to serialize an object to JSON, like this:
data: JSON.stringify({ "command": "on" }),
To support older browsers that don't have the JSON
object, use json2.js which will add it in.
What's currently happening is since you have processData: false
, it's basically sending this: ({"command":"on"}).toString()
which is [object Object]
...what you see in your request.
Obtaining ExitCode using Start-Process and WaitForExit instead of -Wait
The '-Wait' option seemed to block for me even though my process had finished.
I tried Adrian's solution and it works. But I used Wait-Process instead of relying on a side effect of retrieving the process handle.
So:
$proc = Start-Process $msbuild -PassThru
Wait-Process -InputObject $proc
if ($proc.ExitCode -ne 0) {
Write-Warning "$_ exited with status code $($proc.ExitCode)"
}
Putting a simple if-then-else statement on one line
General ternary syntax:
value_true if <test> else value_false
Another way can be:
[value_false, value_true][<test>]
e.g:
count = [0,N+1][count==N]
This evaluates both branches before choosing one. To only evaluate the chosen branch:
[lambda: value_false, lambda: value_true][<test>]()
e.g.:
count = [lambda:0, lambda:N+1][count==N]()
Foreign key constraint may cause cycles or multiple cascade paths?
By the sounds of it you have an OnDelete/OnUpdate action on one of your existing Foreign Keys, that will modify your codes table.
So by creating this Foreign Key, you'd be creating a cyclic problem,
E.g. Updating Employees, causes Codes to changed by an On Update Action, causes Employees to be changed by an On Update Action... etc...
If you post your Table Definitions for both tables, & your Foreign Key/constraint definitions we should be able to tell you where the problem is...
Visual studio code CSS indentation and formatting
Wasted an hour finding the best option.
Just putting it together, for easy reading and choosing one them.
Notes:
- CSS and SASS/SCSS/LESS are all related
- HTML, Javascript, Typescript, JSON - VS code is already formatting
- CSS and related - VS code is not formatting as of today
Options:
- To format css/sass/scss/less:
- Prettier
- All css related supported, and not others, I choose this, it works great.
- To format JavaScript/TypeScript/CSS:
- To format JS, CSS, HTML, JSON file (wraps js-beautify)
- To format CSS
- CSS Formatter
- but, only CSS supported, not all the related - not maintained 6+ months
To format:
Press Alt + Shift + F in VS Code, after installing Prettier.
Call a method of a controller from another controller using 'scope' in AngularJS
Here is good Demo in Fiddle how to use shared service in directive and other controllers through $scope.$on
HTML
<div ng-controller="ControllerZero">
<input ng-model="message" >
<button ng-click="handleClick(message);">BROADCAST</button>
</div>
<div ng-controller="ControllerOne">
<input ng-model="message" >
</div>
<div ng-controller="ControllerTwo">
<input ng-model="message" >
</div>
<my-component ng-model="message"></my-component>
JS
var myModule = angular.module('myModule', []);
myModule.factory('mySharedService', function($rootScope) {
var sharedService = {};
sharedService.message = '';
sharedService.prepForBroadcast = function(msg) {
this.message = msg;
this.broadcastItem();
};
sharedService.broadcastItem = function() {
$rootScope.$broadcast('handleBroadcast');
};
return sharedService;
});
By the same way we can use shared service in directive. We can implement controller section into directive and use $scope.$on
myModule.directive('myComponent', function(mySharedService) {
return {
restrict: 'E',
controller: function($scope, $attrs, mySharedService) {
$scope.$on('handleBroadcast', function() {
$scope.message = 'Directive: ' + mySharedService.message;
});
},
replace: true,
template: '<input>'
};
});
And here three our controllers where ControllerZero
used as trigger to invoke prepForBroadcast
function ControllerZero($scope, sharedService) {
$scope.handleClick = function(msg) {
sharedService.prepForBroadcast(msg);
};
$scope.$on('handleBroadcast', function() {
$scope.message = sharedService.message;
});
}
function ControllerOne($scope, sharedService) {
$scope.$on('handleBroadcast', function() {
$scope.message = 'ONE: ' + sharedService.message;
});
}
function ControllerTwo($scope, sharedService) {
$scope.$on('handleBroadcast', function() {
$scope.message = 'TWO: ' + sharedService.message;
});
}
The ControllerOne
and ControllerTwo
listen message
change by using $scope.$on
handler.
Overriding fields or properties in subclasses
You could define something like this:
abstract class Father
{
//Do you need it public?
protected readonly int MyInt;
}
class Son : Father
{
public Son()
{
MyInt = 1;
}
}
By setting the value as readonly, it ensures that the value for that class remains unchanged for the lifetime of the object.
I suppose the next question is: why do you need it?
Editing an item in a list<T>
public changeAttr(int id)
{
list.Find(p => p.IdItem == id).FieldToModify = newValueForTheFIeld;
}
With:
IdItem is the id of the element you want to modify
FieldToModify is the Field of the item that you want to update.
NewValueForTheField is exactly that, the new value.
(It works perfect for me, tested and implemented)
Differences between time complexity and space complexity?
The time and space complexities are not related to each other. They are used to describe how much space/time your algorithm takes based on the input.
Note that both last examples take O(1)
space as you don't create anything. Compare them to
function(list l) {
list c;
for (node in l) {
c.add(node);
}
}
which takes O(n)
space because you create a new list whose size depends on the size of the input in linear way.
Your example shows that time and space complexity might be different. It takes v.length * print.time
to print all the elements. But the space is always the same - O(1)
because you don't create additional objects. So, yes, it is possible that an algorithm has different time and space complexity, as they are not dependent on each other.
How to pass payload via JSON file for curl?
curl
sends POST requests with the default content type of application/x-www-form-urlencoded
. If you want to send a JSON request, you will have to specify the correct content type header:
$ curl -vX POST http://server/api/v1/places.json -d @testplace.json \
--header "Content-Type: application/json"
But that will only work if the server accepts json input. The .json
at the end of the url may only indicate that the output is json, it doesn't necessarily mean that it also will handle json input. The API documentation should give you a hint on whether it does or not.
The reason you get a 401
and not some other error is probably because the server can't extract the auth_token
from your request.
What is the difference between background, backgroundTint, backgroundTintMode attributes in android layout xml?
I tested various combinations of android:background
, android:backgroundTint
and android:backgroundTintMode
.
android:backgroundTint
applies the color filter to the resource of android:background
when used together with android:backgroundTintMode
.
Here are the results:
Here's the code if you want to experiment further:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:orientation="vertical"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:showIn="@layout/activity_main">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="32dp"
android:textSize="45sp"
android:background="#37AEE4"
android:text="Background" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="32dp"
android:textSize="45sp"
android:backgroundTint="#FEFBDE"
android:text="Background tint" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="32dp"
android:textSize="45sp"
android:background="#37AEE4"
android:backgroundTint="#FEFBDE"
android:text="Both together" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="32dp"
android:textSize="45sp"
android:background="#37AEE4"
android:backgroundTint="#FEFBDE"
android:backgroundTintMode="multiply"
android:text="With tint mode" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="32dp"
android:textSize="45sp"
android:text="Without any" />
</LinearLayout>
How can I schedule a job to run a SQL query daily?
Using T-SQL:
My job is executing stored procedure. You can easy change @command
to run your sql.
EXEC msdb.dbo.sp_add_job
@job_name = N'MakeDailyJob',
@enabled = 1,
@description = N'Procedure execution every day' ;
EXEC msdb.dbo.sp_add_jobstep
@job_name = N'MakeDailyJob',
@step_name = N'Run Procedure',
@subsystem = N'TSQL',
@command = 'exec BackupFromConfig';
EXEC msdb.dbo.sp_add_schedule
@schedule_name = N'Everyday schedule',
@freq_type = 4, -- daily start
@freq_interval = 1,
@active_start_time = '230000' ; -- start time 23:00:00
EXEC msdb.dbo.sp_attach_schedule
@job_name = N'MakeDailyJob',
@schedule_name = N'Everyday schedule' ;
EXEC msdb.dbo.sp_add_jobserver
@job_name = N'MakeDailyJob',
@server_name = @@servername ;
Convert byte[] to char[]
byte[] a = new byte[50];
char [] cArray= System.Text.Encoding.ASCII.GetString(a).ToCharArray();
From the URL thedixon posted
http://bytes.com/topic/c-sharp/answers/250261-byte-char
You cannot ToCharArray the byte without converting it to a string first.
To quote Jon Skeet there
There's no need for the copying here -
just use Encoding.GetChars. However,
there's no guarantee that ASCII is
going to be the appropriate encoding
to use.
Scatter plot with error bars
#some example data
set.seed(42)
df <- data.frame(x = rep(1:10,each=5), y = rnorm(50))
#calculate mean, min and max for each x-value
library(plyr)
df2 <- ddply(df,.(x),function(df) c(mean=mean(df$y),min=min(df$y),max=max(df$y)))
#plot error bars
library(Hmisc)
with(df2,errbar(x,mean,max,min))
grid(nx=NA,ny=NULL)
How to stop a looping thread in Python?
My solution is:
import threading, time
def a():
t = threading.currentThread()
while getattr(t, "do_run", True):
print('Do something')
time.sleep(1)
def getThreadByName(name):
threads = threading.enumerate() #Threads list
for thread in threads:
if thread.name == name:
return thread
threading.Thread(target=a, name='228').start() #Init thread
t = getThreadByName('228') #Get thread by name
time.sleep(5)
t.do_run = False #Signal to stop thread
t.join()
JSON Naming Convention (snake_case, camelCase or PascalCase)
There is no SINGLE standard, but I have seen 3 styles you mention ("Pascal/Microsoft", "Java" (camelCase
) and "C" (underscores, snake_case
)) -- as well as at least one more, kebab-case
like longer-name
).
It mostly seems to depend on what background developers of the service in question had; those with c/c++ background (or languages that adopt similar naming, which includes many scripting languages, ruby etc) often choose underscore variant; and rest similarly (Java vs .NET). Jackson library that was mentioned, for example, assumes Java bean naming convention (camelCase
)
UPDATE: my definition of "standard" is a SINGLE convention. So while one could claim "yes, there are many standards", to me there are multiple Naming Conventions
, none of which is "The" standard overall. One of them could be considered the standard for specific platform, but given that JSON is used for interoperability between platforms that may or may not make much sense.
What is the most robust way to force a UIView to redraw?
The money-back guaranteed, reinforced-concrete-solid way to force a view to draw synchronously (before returning to the calling code) is to configure the CALayer
's interactions with your UIView
subclass.
In your UIView subclass, create a displayNow()
method that tells the layer to “set course for display” then to “make it so”:
Swift
/// Redraws the view's contents immediately.
/// Serves the same purpose as the display method in GLKView.
public func displayNow()
{
let layer = self.layer
layer.setNeedsDisplay()
layer.displayIfNeeded()
}
Objective-C
/// Redraws the view's contents immediately.
/// Serves the same purpose as the display method in GLKView.
- (void)displayNow
{
CALayer *layer = self.layer;
[layer setNeedsDisplay];
[layer displayIfNeeded];
}
Also implement a draw(_: CALayer, in: CGContext)
method that'll call your private/internal drawing method (which works since every UIView
is a CALayerDelegate
):
Swift
/// Called by our CALayer when it wants us to draw
/// (in compliance with the CALayerDelegate protocol).
override func draw(_ layer: CALayer, in context: CGContext)
{
UIGraphicsPushContext(context)
internalDraw(self.bounds)
UIGraphicsPopContext()
}
Objective-C
/// Called by our CALayer when it wants us to draw
/// (in compliance with the CALayerDelegate protocol).
- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)context
{
UIGraphicsPushContext(context);
[self internalDrawWithRect:self.bounds];
UIGraphicsPopContext();
}
And create your custom internalDraw(_: CGRect)
method, along with fail-safe draw(_: CGRect)
:
Swift
/// Internal drawing method; naming's up to you.
func internalDraw(_ rect: CGRect)
{
// @FILLIN: Custom drawing code goes here.
// (Use `UIGraphicsGetCurrentContext()` where necessary.)
}
/// For compatibility, if something besides our display method asks for draw.
override func draw(_ rect: CGRect) {
internalDraw(rect)
}
Objective-C
/// Internal drawing method; naming's up to you.
- (void)internalDrawWithRect:(CGRect)rect
{
// @FILLIN: Custom drawing code goes here.
// (Use `UIGraphicsGetCurrentContext()` where necessary.)
}
/// For compatibility, if something besides our display method asks for draw.
- (void)drawRect:(CGRect)rect {
[self internalDrawWithRect:rect];
}
And now just call myView.displayNow()
whenever you really-really need it to draw (such as from a CADisplayLink
callback). Our displayNow()
method will tell the CALayer
to displayIfNeeded()
, which will synchronously call back into our draw(_:,in:)
and do the drawing in internalDraw(_:)
, updating the visual with what's drawn into the context before moving on.
This approach is similar to @RobNapier's above, but has the advantage of calling displayIfNeeded()
in addition to setNeedsDisplay()
, which makes it synchronous.
This is possible because CALayer
s expose more drawing functionality than UIView
s do— layers are lower-level than views and designed explicitly for the purpose of highly-configurable drawing within the layout, and (like many things in Cocoa) are designed to be used flexibly (as a parent class, or as a delegator, or as a bridge to other drawing systems, or just on their own). Proper usage of the CALayerDelegate
protocol makes all this possible.
More information about the configurability of CALayer
s can be found in the Setting Up Layer Objects section of the Core Animation Programming Guide.
Finding all objects that have a given property inside a collection
I have been using Google Collections (now called Guava) for this kind of problem. There is a class called Iterables that can take an interface called Predicate as a parameter of a method that is really helpful.
Cat theOne = Iterables.find(cats, new Predicate<Cat>() {
public boolean apply(Cat arg) { return arg.age() == 3; }
});
Check it here!
disable a hyperlink using jQuery
Removing the href
attribute definitely seems to the way to go. If for some reason you need it later, I would just store it in another attribute, e.g.
$(".my-link").each(function() {
$(this).attr("data-oldhref", $(this).attr("href"));
$(this).removeAttr("href");
});
This is the only way to do it that will make the link appear disabled as well without writing custom CSS. Just binding a click handler to false will make the link appear like a normal link, but nothing will happen when clicking on it, which may be confusing to users. If you are going to go the click handler route, I would at least also .addClass("link-disabled")
and write some CSS that makes links with that class appear like normal text.
How to remove all subviews of a view in Swift?
EDIT: (thanks Jeremiah / Rollo)
By far the best way to do this in Swift for iOS is:
view.subviews.forEach({ $0.removeFromSuperview() }) // this gets things done
view.subviews.map({ $0.removeFromSuperview() }) // this returns modified array
^^ These features are fun!
let funTimes = ["Awesome","Crazy","WTF"]
extension String {
func readIt() {
print(self)
}
}
funTimes.forEach({ $0.readIt() })
//// END EDIT
Just do this:
for view in self.view.subviews {
view.removeFromSuperview()
}
Or if you are looking for a specific class
for view:CustomViewClass! in self.view.subviews {
if view.isKindOfClass(CustomViewClass) {
view.doClassThing()
}
}
SQL Transaction Error: The current transaction cannot be committed and cannot support operations that write to the log file
You always need to check for XACT_STATE()
, irrelevant of the XACT_ABORT
setting. I have an example of a template for stored procedures that need to handle transactions in the TRY/CATCH context at Exception handling and nested transactions:
create procedure [usp_my_procedure_name]
as
begin
set nocount on;
declare @trancount int;
set @trancount = @@trancount;
begin try
if @trancount = 0
begin transaction
else
save transaction usp_my_procedure_name;
-- Do the actual work here
lbexit:
if @trancount = 0
commit;
end try
begin catch
declare @error int, @message varchar(4000), @xstate int;
select @error = ERROR_NUMBER(),
@message = ERROR_MESSAGE(),
@xstate = XACT_STATE();
if @xstate = -1
rollback;
if @xstate = 1 and @trancount = 0
rollback
if @xstate = 1 and @trancount > 0
rollback transaction usp_my_procedure_name;
raiserror ('usp_my_procedure_name: %d: %s', 16, 1, @error, @message) ;
end catch
end
jQuery UI Alert Dialog as a replacement for alert()
Using some of the info in here I ended up creating my own function to use.
Could be used as...
custom_alert();
custom_alert( 'Display Message' );
custom_alert( 'Display Message', 'Set Title' );
jQuery UI Alert Replacement
function custom_alert( message, title ) {
if ( !title )
title = 'Alert';
if ( !message )
message = 'No Message to Display.';
$('<div></div>').html( message ).dialog({
title: title,
resizable: false,
modal: true,
buttons: {
'Ok': function() {
$( this ).dialog( 'close' );
}
}
});
}
Serializing list to JSON
Yes, but then what do you do about the django objects? simple json tends to choke on them.
If the objects are individual model objects (not querysets, e.g.), I have occasionally stored the model object type and the pk, like so:
seralized_dict = simplejson.dumps(my_dict,
default=lambda a: "[%s,%s]" % (str(type(a)), a.pk)
)
to de-serialize, you can reconstruct the object referenced with model.objects.get(). This doesn't help if you are interested in the object details at the type the dict is stored, but it's effective if all you need to know is which object was involved.
Creating folders inside a GitHub repository without using Git
You can also just enter the website and:
- Choose a repository you have write access to (example URL)
- Click "Upload files"
- Drag and drop a folder with files into the "Drag files here to add them to your repository" area.
The same limitation applies here: the folder must contain at least one file inside it.
Collections.emptyList() returns a List<Object>?
Since Java 8 this kind of code compiles as expected and the type parameter gets inferred by the compiler.
public Person(String name) {
this(name, Collections.emptyList()); // Inferred to List<String> in Java 8
}
public Person(String name, List<String> nicknames) {
this.name = name;
this.nicknames = nicknames;
}
The new thing in Java 8 is that the target type of an expression will be used to infer type parameters of its sub-expressions. Before Java 8 only direct assignments and arguments to methods where used for type parameter inference.
In this case the parameter type of the constructor will be the target type for Collections.emptyList()
, and the return value type will get chosen to match the parameter type.
This mechanism was added in Java 8 mainly to be able to compile lambda expressions, but it improves type inferences generally.
Java is getting closer to proper Hindley–Milner type inference with every release!