Determining image file size + dimensions via Javascript?
You can find dimension of an image on the page using something like
document.getElementById('someImage').width
file size, however, you will have to use something server-side
Laravel: Error [PDOException]: Could not Find Driver in PostgreSQL
Be sure to configure the 'default' key in app/config/database.php
For postgres, this would be 'default' => 'postgres',
If you are receiving a [PDOException] could not find driver error, check to see if you have the correct PHP extensions installed. You need pdo_pgsql.so and pgsql.so installed and enabled. Instructions on how to do this vary between operating systems.
For Windows, the pgsql extensions should come pre-downloaded with the official PHP distribution. Just edit your php.ini and uncomment the lines extension=pdo_pgsql.so and extension=pgsql.so
Also, in php.ini, make sure extension_dir is set to the proper directory. It should be a folder called extensions or ext or similar inside your PHP install directory.
Finally, copy libpq.dll from C:\wamp\bin\php\php5.*\ into C:\wamp\bin\apache*\bin and restart all services through the WampServer interface.
If you still get the exception, you may need to add the postgres \bin directory to your PATH:
- System Properties -> Advanced tab -> Environment Variables
- In 'System variables' group on lower half of window, scroll through and find the
PATHentry. - Select it and click Edit
- At the end of the existing entry, put the full path to your postgres bin directory. The bin folder should be located in the root of your postgres installation directory.
- Restart any open command prompts, or to be certain, restart your computer.
This should hopefully resolve any problems. For more information see:
milliseconds to time in javascript
An Easier solution would be the following:
var d = new Date();
var n = d.getMilliseconds();
python: Change the scripts working directory to the script's own directory
Don't do this.
Your scripts and your data should not be mashed into one big directory. Put your code in some known location (site-packages or /var/opt/udi or something) separate from your data. Use good version control on your code to be sure that you have current and previous versions separated from each other so you can fall back to previous versions and test future versions.
Bottom line: Do not mingle code and data.
Data is precious. Code comes and goes.
Provide the working directory as a command-line argument value. You can provide a default as an environment variable. Don't deduce it (or guess at it)
Make it a required argument value and do this.
import sys
import os
working= os.environ.get("WORKING_DIRECTORY","/some/default")
if len(sys.argv) > 1: working = sys.argv[1]
os.chdir( working )
Do not "assume" a directory based on the location of your software. It will not work out well in the long run.
how can the textbox width be reduced?
<input type="text" style="width:50px;"/>
I am getting an "Invalid Host header" message when connecting to webpack-dev-server remotely
I just experienced this issue while using the Windows Subsystem for Linux (WSL2), so I will also share this solution.
My objective was to render the output from webpack both at wsl:3000 and localhost:3000, thereby creating an alternate local endpoint.
As you might expect, this initially caused the "Invalid Host header" error to arise. Nothing seemed to help until I added the devServer config option shown below.
module.exports = {
//...
devServer: {
proxy: [
{
context: ['http://wsl:3000'],
target: 'http://localhost:3000',
},
],
},
}
This fixed the "bug" without introducing any security risks.
Reference: webpack DevServer docs
MySQL LIMIT on DELETE statement
There is a workaround to solve this problem by using a derived table.
DELETE t1 FROM test t1 JOIN (SELECT t.id FROM test LIMIT 1) t2 ON t1.id = t2.id
Because the LIMIT is inside the derived table the join will match only 1 row and thus the query will delete only this row.
animating addClass/removeClass with jQuery
Since you are not worried about IE, why not just use css transitions to provide the animation and jQuery to change the classes. Live example: http://jsfiddle.net/tw16/JfK6N/
#someDiv{
-webkit-transition: all 0.5s ease;
-moz-transition: all 0.5s ease;
-o-transition: all 0.5s ease;
transition: all 0.5s ease;
}
How to open a local disk file with JavaScript?
The HTML5 fileReader facility does allow you to process local files, but these MUST be selected by the user, you cannot go rooting about the users disk looking for files.
I currently use this with development versions of Chrome (6.x). I don't know what other browsers support it.
PHP Unset Array value effect on other indexes
Test it yourself, but here's the output.
php -r '$a=array("a","b","c"); print_r($a); unset($a[1]); print_r($a);'
Array
(
[0] => a
[1] => b
[2] => c
)
Array
(
[0] => a
[2] => c
)
What's the difference between primitive and reference types?
As many have stated more or less correctly what reference and primitive types are, one might be interested that we have some more relevant types in Java. Here is the complete lists of types in java (as far as I am aware of (JDK 11)).
Primitive Type
Describes a value (and not a type).
11
Reference Type
Describes a concrete type which instances extend Object (interface, class, enum, array). Furthermore TypeParameter is actually a reference type!
Integer
Note: The difference between primitive and reference type makes it necessary to rely on boxing to convert primitives in Object instances and vise versa.
Note2: A type parameter describes a type having an optional lower or upper bound and can be referenced by name within its context (in contrast to the wild card type). A type parameter typically can be applied to parameterized types (classes/interfaces) and methods. The parameter type defines a type identifier.
Wildcard Type
Expresses an unknown type (like any in TypeScript) that can have a lower or upper bound by using super or extend.
? extends List<String>
? super ArrayList<String>
Void Type
Nothingness. No value/instance possible.
void method();
Null Type
The only representation is 'null'. It is used especially during type interference computations. Null is a special case logically belonging to any type (can be assigned to any variable of any type) but is actual not considered an instance of any type (e.g. (null instanceof Object) == false).
null
Union Type
A union type is a type that is actual a set of alternative types. Sadly in Java it only exists for the multi catch statement.
catch(IllegalStateException | IOException e) {}
Interference Type
A type that is compatibile to multiple types. Since in Java a class has at most one super class (Object has none), interference types allow only the first type to be a class and every other type must be an interface type.
void method(List<? extends List<?> & Comparable> comparableList) {}
Unknown Type
The type is unknown. That is the case for certain Lambda definitions (not enclosed in brackets, single parameter).
list.forEach(element -> System.out.println(element.toString)); //element is of unknown type
Var Type
Unknown type introduced by a variable declaration spotting the 'var' keyword.
var variable = list.get(0);
A valid provisioning profile for this executable was not found... (again)
In my case, it was the problem when I setup my time manually two month earlier on my iPhone. But when I changed to set time automatically, it worked fine.
Setting -> General -> Date & Time -> set time automatically
If it does not work then set time automatically of both mac & iPhone, it may work fine.
Jquery/Ajax call with timer
If you want to set something on a timer, you can use JavaScript's setTimeout or setInterval methods:
setTimeout ( expression, timeout );
setInterval ( expression, interval );
Where expression is a function and timeout and interval are integers in milliseconds. setTimeout runs the timer once and runs the expression once whereas setInterval will run the expression every time the interval passes.
So in your case it would work something like this:
setInterval(function() {
//call $.ajax here
}, 5000); //5 seconds
As far as the Ajax goes, see jQuery's ajax() method. If you run an interval, there is nothing stopping you from calling the same ajax() from other places in your code.
If what you want is for an interval to run every 30 seconds until a user initiates a form submission...and then create a new interval after that, that is also possible:
setInterval() returns an integer which is the ID of the interval.
var id = setInterval(function() {
//call $.ajax here
}, 30000); // 30 seconds
If you store that ID in a variable, you can then call clearInterval(id) which will stop the progression.
Then you can reinstantiate the setInterval() call after you've completed your ajax form submission.
CURRENT_DATE/CURDATE() not working as default DATE value
Currently from MySQL 8 you can set the following to a DATE column:
In MySQL Workbench, in the Default field next to the column, write: (curdate())
If you put just curdate() it will fail. You need the extra ( and ) at the beginning and end.
Generate a dummy-variable
What I normally do to work with this kind of dummy variables is:
(1) how do I generate a dummy variable for observation #10, i.e. for year 1957 (value = 1 at 1957 and zero otherwise)
data$factor_year_1 <- factor ( with ( data, ifelse ( ( year == 1957 ), 1 , 0 ) ) )
(2) how do I generate a dummy-variable which is zero before 1957 and takes the value 1 from 1957 and onwards to 2009?
data$factor_year_2 <- factor ( with ( data, ifelse ( ( year < 1957 ), 0 , 1 ) ) )
Then, I can introduce this factor as a dummy variable in my models. For example, to see whether there is a long-term trend in a varible y :
summary ( lm ( y ~ t, data = data ) )
Hope this helps!
SQL Insert into table only if record doesn't exist
This might be a simple solution to achieve this:
INSERT INTO funds (ID, date, price)
SELECT 23, DATE('2013-02-12'), 22.5
FROM dual
WHERE NOT EXISTS (SELECT 1
FROM funds
WHERE ID = 23
AND date = DATE('2013-02-12'));
p.s. alternatively (if ID a primary key):
INSERT INTO funds (ID, date, price)
VALUES (23, DATE('2013-02-12'), 22.5)
ON DUPLICATE KEY UPDATE ID = 23; -- or whatever you need
see this Fiddle.
Bootstrap: 'TypeError undefined is not a function'/'has no method 'tab'' when using bootstrap-tabs
I actually managed to work out what I was doing wrong (and it was my fault).
I'm used to using pre-jQuery Rails, so when I included the Bootstrap JS files I didn't think that including the version of jQuery bundled with them would cause any issues, however when I removed that one JS file everything started working perfectly.
Lesson learnt, triple check which JS files are loaded, see if there's any conflicts.
JAXB :Need Namespace Prefix to all the elements
To specify more than one namespace to provide prefixes, use something like:
@javax.xml.bind.annotation.XmlSchema(
namespace = "urn:oecd:ties:cbc:v1",
elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED,
xmlns ={@XmlNs(prefix="cbc", namespaceURI="urn:oecd:ties:cbc:v1"),
@XmlNs(prefix="iso", namespaceURI="urn:oecd:ties:isocbctypes:v1"),
@XmlNs(prefix="stf", namespaceURI="urn:oecd:ties:stf:v4")})
... in package-info.java
How to override trait function and call it from the overridden function?
Another variation: Define two functions in the trait, a protected one that performs the actual task, and a public one which in turn calls the protected one.
This just saves classes from having to mess with the 'use' statement if they want to override the function, since they can still call the protected function internally.
trait A {
protected function traitcalc($v) {
return $v+1;
}
function calc($v) {
return $this->traitcalc($v);
}
}
class MyClass {
use A;
function calc($v) {
$v++;
return $this->traitcalc($v);
}
}
class MyOtherClass {
use A;
}
print (new MyClass())->calc(2); // will print 4
print (new MyOtherClass())->calc(2); // will print 3
How do you beta test an iphone app?
With iOS 8, Xcode 6, iTunes Connect and TestFlight you don't need UDIDs and Ad Hocs anymore. You will just need an Apple ID from your beta tester. Right now you can only beta test your app with 25 internal testers, but soon 1000 external testers will be available too. This blog post shows you how to setup a beta test with internal testers.
Is generator.next() visible in Python 3?
Try:
next(g)
Check out this neat table that shows the differences in syntax between 2 and 3 when it comes to this.
Eclipse JPA Project Change Event Handler (waiting)
I had the same problem and I ended up finding out that this seems to be a known bug in DALI (Eclipse Java Persistence Tools) since at least eclipse 3.8 which could cause the save action in the java editor to be extremly slow.
Since this hasn't been fully resolved in Kepler (20130614-0229) yet and because I don't need JPT/DALI in my eclipse I ended up manually removing the org.eclipse.jpt features and plugins.
What I did was:
1.) exit eclipse
2.) go to my eclipse install directory
cd eclipse
and execute these steps:
*nix:
mkdir disabled
mkdir disabled/features disabled/plugins
mv plugins/org.eclipse.jpt.* disabled/plugins
mv features/org.eclipse.jpt.* disabled/features
windows:
mkdir disabled
mkdir disabled\features
mkdir disabled\plugins
move plugins\org.eclipse.jpt.* disabled\plugins
for /D /R %D in (features\org.eclipse.jpt.*) do move %D disabled\features
3.) Restart eclipse.
After startup and on first use eclipse may warn you that you need to reconfigure your content-assist. Do this in your preferences dialog.
Done.
After uninstalling DALI/JPT my eclipse feels good again. No more blocked UI and waiting for seconds when saving a file.
Oracle insert from select into table with more columns
just select '0' as the value for the desired column
Program "make" not found in PATH
Are you trying to run "Hello world" for the first time? Please make sure you choose proper toolchain. For Windows you have to choose MinGW GCC.
To make MinGW GCC compiler as default or change you original project with error "Program “make” not found in PATH" or "launch failed binary not found eclipse c++" when you trying to run program simply go to Windows >> Preferences >> C\C++ Build >> Tool Chain Editor >> Change Current toolchain to MinGW GCC
Set max-height on inner div so scroll bars appear, but not on parent div
This would work just fine, set the height to desired pixel
#inner-right{
height: 100px;
overflow:auto;
}
Correct way to convert size in bytes to KB, MB, GB in JavaScript
This solution builds upon previous solutions, but takes into account both metric and binary units:
function formatBytes(bytes, decimals, binaryUnits) {
if(bytes == 0) {
return '0 Bytes';
}
var unitMultiple = (binaryUnits) ? 1024 : 1000;
var unitNames = (unitMultiple === 1024) ? // 1000 bytes in 1 Kilobyte (KB) or 1024 bytes for the binary version (KiB)
['Bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']:
['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
var unitChanges = Math.floor(Math.log(bytes) / Math.log(unitMultiple));
return parseFloat((bytes / Math.pow(unitMultiple, unitChanges)).toFixed(decimals || 0)) + ' ' + unitNames[unitChanges];
}
Examples:
formatBytes(293489203947847, 1); // 293.5 TB
formatBytes(1234, 0); // 1 KB
formatBytes(4534634523453678343456, 2); // 4.53 ZB
formatBytes(4534634523453678343456, 2, true)); // 3.84 ZiB
formatBytes(4566744, 1); // 4.6 MB
formatBytes(534, 0); // 534 Bytes
formatBytes(273403407, 0); // 273 MB
Android center view in FrameLayout doesn't work
I'd suggest a RelativeLayout instead of a FrameLayout.
Assuming that you want to have the TextView always below the ImageView I'd use following layout.
<?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="wrap_content">
<ImageView
android:id="@+id/imageview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerInParent="true"
android:src="@drawable/icon"
android:visibility="visible"/>
<TextView
android:id="@+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_below="@id/imageview"
android:gravity="center"
android:text="@string/hello"/>
</RelativeLayout>
Note that if you set the visibility of an element to gone then the space that element would consume is gone whereas when you use invisible instead the space it'd consume will be preserved.
If you want to have the TextView on top of the ImageView then simply leave out the android:layout_alignParentTop or set it to false and on the TextView leave out the android:layout_below="@id/imageview" attribute. Like this.
<?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="wrap_content">
<ImageView
android:id="@+id/imageview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="false"
android:layout_centerInParent="true"
android:src="@drawable/icon"
android:visibility="visible"/>
<TextView
android:id="@+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:gravity="center"
android:text="@string/hello"/>
</RelativeLayout>
I hope this is what you were looking for.
Extract a subset of a dataframe based on a condition involving a field
Just to extend the answer above you can also index your columns rather than specifying the column names which can also be useful depending on what you're doing. Given that your location is the first field it would look like this:
bar <- foo[foo[ ,1] == "there", ]
This is useful because you can perform operations on your column value, like looping over specific columns (and you can do the same by indexing row numbers too).
This is also useful if you need to perform some operation on more than one column because you can then specify a range of columns:
foo[foo[ ,c(1:N)], ]
Or specific columns, as you would expect.
foo[foo[ ,c(1,5,9)], ]
Use a JSON array with objects with javascript
By 'JSON array containing objects' I guess you mean a string containing JSON?
If so you can use the safe var myArray = JSON.parse(myJSON) method (either native or included using JSON2), or the usafe var myArray = eval("(" + myJSON + ")"). eval should normally be avoided, but if you are certain that the content is safe, then there is no problem.
After that you just iterate over the array as normal.
for (var i = 0; i < myArray.length; i++) {
alert(myArray[i].Title);
}
read file from assets
one line solution for kotlin:
fun readFileText(fileName: String): String {
return assets.open(fileName).bufferedReader().use { it.readText() }
}
Also you can use it as extension function everyWhere
fun Context.readTextFromAsset(fileName : String) : String{
return assets.open(fileName).bufferedReader().use {
it.readText()}
}
Simply call in any context Class
context.readTextFromAsset("my file name")
How can I start an Activity from a non-Activity class?
You can define a context for your application say ExampleContext which will hold the context of your application and then use it to instantiate an activity like this:
var intent = new Intent(Application.ApplicationContext, typeof(Activity2));
intent.AddFlags(ActivityFlags.NewTask);
Application.ApplicationContext.StartActivity(intent);
Please bear in mind that this code is written in C# as I use MonoDroid, but I believe it is very similar to Java. For how to create an ApplicationContext look at this thread
This is how I made my Application Class
[Application]
public class Application : Android.App.Application, IApplication
{
public Application(IntPtr handle, JniHandleOwnership transfer) : base(handle, transfer)
{
}
public object MyObject { get; set; }
}
generate random string for div id
i like this simple one:
function randstr(prefix)
{
return Math.random().toString(36).replace('0.',prefix || '');
}
since id should (though not must) start with a letter, i'd use it like this:
let div_id = randstr('youtube_div_');
some example values:
youtube_div_4vvbgs01076
youtube_div_1rofi36hslx
youtube_div_i62wtpptnpo
youtube_div_rl4fc05xahs
youtube_div_jb9bu85go7
youtube_div_etmk8u7a3r9
youtube_div_7jrzty7x4ft
youtube_div_f41t3hxrxy
youtube_div_8822fmp5sc8
youtube_div_bv3a3flv425
HttpContext.Current.Request.Url.Host what it returns?
The Host property will return the domain name you used when accessing the site. So, in your development environment, since you're requesting
http://localhost:950/m/pages/Searchresults.aspx?search=knife&filter=kitchen
It's returning localhost. You can break apart your URL like so:
Protocol: http
Host: localhost
Port: 950
PathAndQuery: /m/pages/SearchResults.aspx?search=knight&filter=kitchen
How to query a MS-Access Table from MS-Excel (2010) using VBA
Option Explicit
Const ConnectionStrngAccessPW As String = _"Provider=Microsoft.ACE.OLEDB.12.0;
Data Source=C:\Users\BARON\Desktop\Test_DB-PW.accdb;
Jet OLEDB:Database Password=123pass;"
Const ConnectionStrngAccess As String = _"Provider=Microsoft.ACE.OLEDB.12.0;
Data Source=C:\Users\BARON\Desktop\Test_DB.accdb;
Persist Security Info=False;"
'C:\Users\BARON\Desktop\Test.accdb
Sub ModifyingExistingDataOnAccessDB()
Dim TableConn As ADODB.Connection
Dim TableData As ADODB.Recordset
Set TableConn = New ADODB.Connection
Set TableData = New ADODB.Recordset
TableConn.ConnectionString = ConnectionStrngAccess
TableConn.Open
On Error GoTo CloseConnection
With TableData
.ActiveConnection = TableConn
'.Source = "SELECT Emp_Age FROM Roster WHERE Emp_Age > 40;"
.Source = "Roster"
.LockType = adLockOptimistic
.CursorType = adOpenForwardOnly
.Open
On Error GoTo CloseRecordset
Do Until .EOF
If .Fields("Emp_Age").Value > 40 Then
.Fields("Emp_Age").Value = 40
.Update
End If
.MoveNext
Loop
.MoveFirst
MsgBox "Update Complete"
End With
CloseRecordset:
TableData.CancelUpdate
TableData.Close
CloseConnection:
TableConn.Close
Set TableConn = Nothing
Set TableData = Nothing
End Sub
Sub AddingDataToAccessDB()
Dim TableConn As ADODB.Connection
Dim TableData As ADODB.Recordset
Dim r As Range
Set TableConn = New ADODB.Connection
Set TableData = New ADODB.Recordset
TableConn.ConnectionString = ConnectionStrngAccess
TableConn.Open
On Error GoTo CloseConnection
With TableData
.ActiveConnection = TableConn
.Source = "Roster"
.LockType = adLockOptimistic
.CursorType = adOpenForwardOnly
.Open
On Error GoTo CloseRecordset
Sheet3.Activate
For Each r In Range("B3", Range("B3").End(xlDown))
MsgBox "Adding " & r.Offset(0, 1)
.AddNew
.Fields("Emp_ID").Value = r.Offset(0, 0).Value
.Fields("Emp_Name").Value = r.Offset(0, 1).Value
.Fields("Emp_DOB").Value = r.Offset(0, 2).Value
.Fields("Emp_SOD").Value = r.Offset(0, 3).Value
.Fields("Emp_EOD").Value = r.Offset(0, 4).Value
.Fields("Emp_Age").Value = r.Offset(0, 5).Value
.Fields("Emp_Gender").Value = r.Offset(0, 6).Value
.Update
Next r
MsgBox "Update Complete"
End With
CloseRecordset:
TableData.Close
CloseConnection:
TableConn.Close
Set TableConn = Nothing
Set TableData = Nothing
End Sub
Download/Stream file from URL - asp.net
The accepted solution from Dallas was working for us if we use Load Balancer on the Citrix Netscaler (without WAF policy).
The download of the file doesn't work through the LB of the Netscaler when it is associated with WAF as the current scenario (Content-length not being correct) is a RFC violation and AppFW resets the connection, which doesn't happen when WAF policy is not associated.
So what was missing was:
Response.End();
See also: Trying to stream a PDF file with asp.net is producing a "damaged file"
URL for public Amazon S3 bucket
The URL structure you're referring to is called the REST endpoint, as opposed to the Web Site Endpoint.
Note: Since this answer was originally written, S3 has rolled out dualstack support on REST endpoints, using new hostnames, while leaving the existing hostnames in place. This is now integrated into the information provided, below.
If your bucket is really in the us-east-1 region of AWS -- which the S3 documentation formerly referred to as the "US Standard" region, but was subsequently officially renamed to the "U.S. East (N. Virginia) Region" -- then http://s3-us-east-1.amazonaws.com/bucket/ is not the correct form for that endpoint, even though it looks like it should be. The correct format for that region is either http://s3.amazonaws.com/bucket/ or http://s3-external-1.amazonaws.com/bucket/.¹
The format you're using is applicable to all the other S3 regions, but not US Standard US East (N. Virginia) [us-east-1].
S3 now also has dual-stack endpoint hostnames for the REST endpoints, and unlike the original endpoint hostnames, the names of these have a consistent format across regions, for example s3.dualstack.us-east-1.amazonaws.com. These endpoints support both IPv4 and IPv6 connectivity and DNS resolution, but are otherwise functionally equivalent to the existing REST endpoints.
If your permissions and configuration are set up such that the web site endpoint works, then the REST endpoint should work, too.
However... the two endpoints do not offer the same functionality.
Roughly speaking, the REST endpoint is better-suited for machine access and the web site endpoint is better suited for human access, since the web site endpoint offers friendly error messages, index documents, and redirects, while the REST endpoint doesn't. On the other hand, the REST endpoint offers HTTPS and support for signed URLs, while the web site endpoint doesn't.
Choose the correct type of endpoint (REST or web site) for your application:
http://docs.aws.amazon.com/AmazonS3/latest/dev/WebsiteEndpoints.html#WebsiteRestEndpointDiff
¹ s3-external-1.amazonaws.com has been referred to as the "Northern Virginia endpoint," in contrast to the "Global endpoint" s3.amazonaws.com. It was unofficially possible to get read-after-write consistency on new objects in this region if the "s3-external-1" hostname was used, because this would send you to a subset of possible physical endpoints that could provide that functionality. This behavior is now officially supported on this endpoint, so this is probably the better choice in many applications. Previously, s3-external-2 had been referred to as the "Pacific Northwest endpoint" for US-Standard, though it is now a CNAME in DNS for s3-external-1 so s3-external-2 appears to have no purpose except backwards-compatibility.
ValueError: invalid literal for int () with base 10
Pythonic way of iterating over a file and converting to int:
for line in open(fname):
if line.strip(): # line contains eol character(s)
n = int(line) # assuming single integer on each line
What you're trying to do is slightly more complicated, but still not straight-forward:
h = open(fname)
for line in h:
if line.strip():
[int(next(h).strip()) for _ in range(4)] # list of integers
This way it processes 5 lines at the time. Use h.next() instead of next(h) prior to Python 2.6.
The reason you had ValueError is because int cannot convert an empty string to the integer. In this case you'd need to either check the content of the string before conversion, or except an error:
try:
int('')
except ValueError:
pass # or whatever
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo
This error can also be the ultimate sign of a dumb mistake (like when I - I mean, cough, like when a friend of mine who showed me their code once) where they try to execute code outside of a method like trying to do this:
SQLiteDatabase db = openOrCreateDatabase("DB", MODE_PRIVATE, null); //trying to perform function where you can only set up objects, primitives, etc
@Override
public void onCreate(Bundle savedInstanceState) {
....
}
rather than this:
SQLiteDatabase db;
@Override
public void onCreate(Bundle savedInstanceState) {
db = openOrCreateDatabase("DB", MODE_PRIVATE, null);
....
}
Java ArrayList Index
Read more about Array and ArrayList
List<String> aList = new ArrayList<String>();
aList.add("apple");
aList.add("banana");
aList.add("orange");
String result = alist.get(1); //this will retrieve banana
Note: Index starts from 0 i.e. Zero
Swap two items in List<T>
There is no existing Swap-method, so you have to create one yourself. Of course you can linqify it, but that has to be done with one (unwritten?) rules in mind: LINQ-operations do not change the input parameters!
In the other "linqify" answers, the (input) list is modified and returned, but this action brakes that rule. If would be weird if you have a list with unsorted items, do a LINQ "OrderBy"-operation and than discover that the input list is also sorted (just like the result). This is not allowed to happen!
So... how do we do this?
My first thought was just to restore the collection after it was finished iterating. But this is a dirty solution, so do not use it:
static public IEnumerable<T> Swap1<T>(this IList<T> source, int index1, int index2)
{
// Parameter checking is skipped in this example.
// Swap the items.
T temp = source[index1];
source[index1] = source[index2];
source[index2] = temp;
// Return the items in the new order.
foreach (T item in source)
yield return item;
// Restore the collection.
source[index2] = source[index1];
source[index1] = temp;
}
This solution is dirty because it does modify the input list, even if it restores it to the original state. This could cause several problems:
- The list could be readonly which will throw an exception.
- If the list is shared by multiple threads, the list will change for the other threads during the duration of this function.
- If an exception occurs during the iteration, the list will not be restored. (This could be resolved to write an try-finally inside the Swap-function, and put the restore-code inside the finally-block).
There is a better (and shorter) solution: just make a copy of the original list. (This also makes it possible to use an IEnumerable as a parameter, instead of an IList):
static public IEnumerable<T> Swap2<T>(this IList<T> source, int index1, int index2)
{
// Parameter checking is skipped in this example.
// If nothing needs to be swapped, just return the original collection.
if (index1 == index2)
return source;
// Make a copy.
List<T> copy = source.ToList();
// Swap the items.
T temp = copy[index1];
copy[index1] = copy[index2];
copy[index2] = temp;
// Return the copy with the swapped items.
return copy;
}
One disadvantage of this solution is that it copies the entire list which will consume memory and that makes the solution rather slow.
You might consider the following solution:
static public IEnumerable<T> Swap3<T>(this IList<T> source, int index1, int index2)
{
// Parameter checking is skipped in this example.
// It is assumed that index1 < index2. Otherwise a check should be build in and both indexes should be swapped.
using (IEnumerator<T> e = source.GetEnumerator())
{
// Iterate to the first index.
for (int i = 0; i < index1; i++)
yield return source[i];
// Return the item at the second index.
yield return source[index2];
if (index1 != index2)
{
// Return the items between the first and second index.
for (int i = index1 + 1; i < index2; i++)
yield return source[i];
// Return the item at the first index.
yield return source[index1];
}
// Return the remaining items.
for (int i = index2 + 1; i < source.Count; i++)
yield return source[i];
}
}
And if you want to input parameter to be IEnumerable:
static public IEnumerable<T> Swap4<T>(this IEnumerable<T> source, int index1, int index2)
{
// Parameter checking is skipped in this example.
// It is assumed that index1 < index2. Otherwise a check should be build in and both indexes should be swapped.
using(IEnumerator<T> e = source.GetEnumerator())
{
// Iterate to the first index.
for(int i = 0; i < index1; i++)
{
if (!e.MoveNext())
yield break;
yield return e.Current;
}
if (index1 != index2)
{
// Remember the item at the first position.
if (!e.MoveNext())
yield break;
T rememberedItem = e.Current;
// Store the items between the first and second index in a temporary list.
List<T> subset = new List<T>(index2 - index1 - 1);
for (int i = index1 + 1; i < index2; i++)
{
if (!e.MoveNext())
break;
subset.Add(e.Current);
}
// Return the item at the second index.
if (e.MoveNext())
yield return e.Current;
// Return the items in the subset.
foreach (T item in subset)
yield return item;
// Return the first (remembered) item.
yield return rememberedItem;
}
// Return the remaining items in the list.
while (e.MoveNext())
yield return e.Current;
}
}
Swap4 also makes a copy of (a subset of) the source. So worst case scenario, it is as slow and memory consuming as function Swap2.
Android, Java: HTTP POST Request
I'd rather recommend you to use Volley to make GET, PUT, POST... requests.
First, add dependency in your gradle file.
compile 'com.he5ed.lib:volley:android-cts-5.1_r4'
Now, use this code snippet to make requests.
RequestQueue queue = Volley.newRequestQueue(getApplicationContext());
StringRequest postRequest = new StringRequest( com.android.volley.Request.Method.POST, mURL,
new Response.Listener<String>()
{
@Override
public void onResponse(String response) {
// response
Log.d("Response", response);
}
},
new Response.ErrorListener()
{
@Override
public void onErrorResponse(VolleyError error) {
// error
Log.d("Error.Response", error.toString());
}
}
) {
@Override
protected Map<String, String> getParams()
{
Map<String, String> params = new HashMap<String, String>();
//add your parameters here as key-value pairs
params.put("username", username);
params.put("password", password);
return params;
}
};
queue.add(postRequest);
How do I add a tool tip to a span element?
the "title" attribute will be used as the text for tooltip by the browser, if you want to apply style to it consider using some plugins
How can I programmatically generate keypress events in C#?
Easily! (because someone else already did the work for us...)
After spending a lot of time trying to this with the suggested answers I came across this codeplex project Windows Input Simulator which made it simple as can be to simulate a key press:
Install the package, can be done or from the NuGet package manager or from the package manager console like:
Install-Package InputSimulator
Use this 2 lines of code:
inputSimulator = new InputSimulator() inputSimulator.Keyboard.KeyDown(VirtualKeyCode.RETURN)
And that's it!
-------EDIT--------
The project page on codeplex is flagged for some reason, this is the link to the NuGet gallery.
How to set null value to int in c#?
In .Net, you cannot assign a null value to an int or any other struct. Instead, use a Nullable<int>, or int? for short:
int? value = 0;
if (value == 0)
{
value = null;
}
Further Reading
Cannot change column used in a foreign key constraint
The type and definition of foreign key field and reference must be equal. This means your foreign key disallows changing the type of your field.
One solution would be this:
LOCK TABLES
favorite_food WRITE,
person WRITE;
ALTER TABLE favorite_food
DROP FOREIGN KEY fk_fav_food_person_id,
MODIFY person_id SMALLINT UNSIGNED;
Now you can change you person_id
ALTER TABLE person MODIFY person_id SMALLINT UNSIGNED AUTO_INCREMENT;
recreate foreign key
ALTER TABLE favorite_food
ADD CONSTRAINT fk_fav_food_person_id FOREIGN KEY (person_id)
REFERENCES person (person_id);
UNLOCK TABLES;
EDIT: Added locks above, thanks to comments
You have to disallow writing to the database while you do this, otherwise you risk data integrity problems.
I've added a write lock above
All writing queries in any other session than your own ( INSERT, UPDATE, DELETE ) will wait till timeout or UNLOCK TABLES; is executed
http://dev.mysql.com/doc/refman/5.5/en/lock-tables.html
EDIT 2: OP asked for a more detailed explanation of the line "The type and definition of foreign key field and reference must be equal. This means your foreign key disallows changing the type of your field."
From MySQL 5.5 Reference Manual: FOREIGN KEY Constraints
Corresponding columns in the foreign key and the referenced key must have similar internal data types inside InnoDB so that they can be compared without a type conversion. The size and sign of integer types must be the same. The length of string types need not be the same. For nonbinary (character) string columns, the character set and collation must be the same.
Reference list item by index within Django template?
@jennifer06262016, you can definitely add another filter to return the objects inside a django Queryset.
@register.filter
def get_item(Queryset):
return Queryset.your_item_key
In that case, you would type something like this {{ Queryset|index:x|get_item }} into your template to access some dictionary object. It works for me.
Border in shape xml
If you want make a border in a shape xml. You need to use:
For the external border,you need to use:
<stroke/>
For the internal background,you need to use:
<solid/>
If you want to set corners,you need to use:
<corners/>
If you want a padding betwen border and the internal elements,you need to use:
<padding/>
Here is a shape xml example using the above items. It works for me
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<stroke android:width="2dp" android:color="#D0CFCC" />
<solid android:color="#F8F7F5" />
<corners android:radius="10dp" />
<padding android:left="2dp" android:top="2dp" android:right="2dp" android:bottom="2dp" />
</shape>
How can I implement rate limiting with Apache? (requests per second)
Sadly, mod_evasive won't work as expected when used in non-prefork configurations (recent apache setups are mainly MPM)
How to load json into my angular.js ng-model?
As Kris mentions, you can use the $resource service to interact with the server, but I get the impression you are beginning your journey with Angular - I was there last week - so I recommend to start experimenting directly with the $http service. In this case you can call its get method.
If you have the following JSON
[{ "text":"learn angular", "done":true },
{ "text":"build an angular app", "done":false},
{ "text":"something", "done":false },
{ "text":"another todo", "done":true }]
You can load it like this
var App = angular.module('App', []);
App.controller('TodoCtrl', function($scope, $http) {
$http.get('todos.json')
.then(function(res){
$scope.todos = res.data;
});
});
The get method returns a promise object which
first argument is a success callback and the second an error
callback.
When you add $http as a parameter of a function Angular does it magic
and injects the $http resource into your controller.
I've put some examples here
com.android.build.transform.api.TransformException
I'm using AS 1.5.1 and encountered the same problem. But just cleaning the project just wont do, so I tried something.
- clean project
- restart AS
- Sync Project
This worked with me, so I hope this helps.
How to generate service reference with only physical wsdl file
There are two ways to go about this. You can either use the IDE to generate a WSDL, or you can do it via the command line.
1. To create it via the IDE:
In the solution explorer pane, right click on the project that you would like to add the Service to:
Then, you can enter the path to your service WSDL and hit go:
2. To create it via the command line:
Open a VS 2010 Command Prompt (Programs -> Visual Studio 2010 -> Visual Studio Tools)
Then execute:
WSDL /verbose C:\path\to\wsdl
WSDL.exe will then output a .cs file for your consumption.
If you have other dependencies that you received with the file, such as xsd's, add those to the argument list:
WSDL /verbose C:\path\to\wsdl C:\path\to\some\xsd C:\path\to\some\xsd
If you need VB output, use /language:VB in addition to the /verbose.
getting " (1) no such column: _id10 " error
I think you missed a equal sign at:
Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + "" + l, null, null, null, null); Change to:
Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + " = " + l, null, null, null, null); How change default SVN username and password to commit changes?
To use alternate credentials for a single operation, use the --username and --password switches for svn.
To clear previously-saved credentials, delete ~/.subversion/auth. You'll be prompted for credentials the next time they're needed.
These settings are saved in the user's home directory, so if you're using a shared account on "this laptop", be careful - if you allow the client to save your credentials, someone can impersonate you. The first option I provided is the better way to go in this case. At least until you stop using shared accounts on computers, which you shouldn't be doing.
To change credentials you need to do:
rm -rf ~/.subversion/authsvn up( it'll ask you for new username & password )
BigDecimal to string
If you just need to set precision quantity and round the value, the right way to do this is use it's own object for this.
BigDecimal value = new BigDecimal("10.0001");
value = value.setScale(4, RoundingMode.HALF_UP);
System.out.println(value); //the return should be "10.0001"
One of the pillars of Oriented Object Programming (OOP) is "encapsulation", this pillar also says that an object should deal with it's own operations, like in this way:
Locking pattern for proper use of .NET MemoryCache
To avoid the global lock, you can use SingletonCache to implement one lock per key, without exploding memory usage (the lock objects are removed when no longer referenced, and acquire/release is thread safe guaranteeing that only 1 instance is ever in use via compare and swap).
Using it looks like this:
SingletonCache<string, object> keyLocks = new SingletonCache<string, object>();
const string CacheKey = "CacheKey";
static string GetCachedData()
{
string expensiveString =null;
if (MemoryCache.Default.Contains(CacheKey))
{
return MemoryCache.Default[CacheKey] as string;
}
// double checked lock
using (var lifetime = keyLocks.Acquire(url))
{
lock (lifetime.Value)
{
if (MemoryCache.Default.Contains(CacheKey))
{
return MemoryCache.Default[CacheKey] as string;
}
cacheItemPolicy cip = new CacheItemPolicy()
{
AbsoluteExpiration = new DateTimeOffset(DateTime.Now.AddMinutes(20))
};
expensiveString = SomeHeavyAndExpensiveCalculation();
MemoryCache.Default.Set(CacheKey, expensiveString, cip);
return expensiveString;
}
}
}
Code is here on GitHub: https://github.com/bitfaster/BitFaster.Caching
Install-Package BitFaster.Caching
There is also an LRU implementation that is lighter weight than MemoryCache, and has several advantages - faster concurrent reads and writes, bounded size, no background thread, internal perf counters etc. (disclaimer, I wrote it).
ESLint - "window" is not defined. How to allow global variables in package.json
I found it on this page: http://eslint.org/docs/user-guide/configuring
In package.json, this works:
"eslintConfig": {
"globals": {
"window": true
}
}
Use YAML with variables
This is how I was able to configure yaml files to refer to variable.
I have values.yaml where we have root level fields which are used as template variables inside values.yaml
values.yaml
.....
databaseUserPropName: spring.datasource.username
databaseUserName: sa
.....
secrets:
type: Opaque
name: dbservice-secrets
data:
- name: "{{ .Values.databaseUserPropName }}"
value: "{{ .Values.databaseUserName }}"
.....
When referencing these values in secret.yaml, we would use tpl function using syntax {{ tpl TEMPLATE_STRING VALUES }}
secret.yaml
when using inside range i:e iteration
{{ range .Values.deployments.secrets.data }}
{{ tpl .name $ }}: "{{ tpl .value $ }}"
{{ end }}
when directly referring as variable
{{ tpl .Values.deployments.secrets.data.name . }}
{{ tpl .Values.deployments.secrets.data.value . }}
$ - this is global variable and will always point to the root context . - this variable will point to the root context based on where it used.
Access parent's parent from javascript object
If you want get all parents key of a node in a literal object ({}), you can to do that:
(function ($) {
"use strict";
$.defineProperties($, {
parentKeys: {
value: function (object) {
var
traces = [],
queue = [{trace: [], node: object}],
block = function () {
var
node,
nodeKeys,
trace;
// clean the queue
queue = [];
return function (map) {
node = map.node;
nodeKeys = Object.keys(node);
nodeKeys.forEach(function (nodeKey) {
if (typeof node[nodeKey] == "object") {
trace = map.trace.concat(nodeKey);
// put on queue
queue.push({trace: trace, node: node[nodeKey]});
// traces.unshift(trace);
traces.push(trace);
}
});
};
};
while(true) {
if (queue.length) {
queue.forEach(block());
} else {
break;
}
}
return traces;
},
writable: true
}
});
})(Object);
This algorithm uses the FIFO concept for iterate the graphs using the BFS method. This code extend the class Object adding the static method parentKeys that expects a literal Object (hash table - associative array...) of the Javacript, as parameter.
I hope I have helped.
What is the difference between UTF-8 and Unicode?
Unicode is just a standard that defines a character set (UCS) and encodings (UTF) to encode this character set. But in general, Unicode is refered to the character set and not the standard.
Read The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) and Unicode In 5 Minutes.
SQL Query - how do filter by null or not null
How about statusid = statusid. Null is never equal to null.
Want custom title / image / description in facebook share link from a flash app
I have a Joomla Module that displays stuff... and I want to be able to share that stuff on facebook and not the Page's Title Meta Description... so my workaround is to have a secret .php file on the server that gets executed when it detects the FB's
$_SERVER['HTTP_USER_AGENT']
if($_SERVER['HTTP_USER_AGENT'] != 'facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)') {
echo 'Direct Access';
} else {
echo 'FB Accessed';
}
and pass variables with the URL that formats that particular page with the title and meta desciption of the item I want to share from my joomla module...
a name="fb_share" share_url="MYURL/sharer.php?title=TITLE&desc=DESC"
hope this helps...
Mysql select distinct
You can use group by instead of distinct. Because when you use distinct, you'll get struggle to select all values from table. Unlike when you use group by, you can get distinct values and also all fields in table.
Display current path in terminal only
If you just want to get the information of current directory, you can type:
pwd
and you don't need to use the Nautilus, or you can use a teamviewer software to remote connect to the computer, you can get everything you want.
Laravel: Get Object From Collection By Attribute
I have to point out that there is a small but absolutely CRITICAL error in kalley's answer. I struggled with this for several hours before realizing:
Inside the function, what you are returning is a comparison, and thus something like this would be more correct:
$desired_object = $food->filter(function($item) {
return ($item->id **==** 24);
})->first();
contenteditable change events
This thread was very helpful while I was investigating the subject.
I've modified some of the code available here into a jQuery plugin so it is in a re-usable form, primarily to satisfy my needs but others may appreciate a simpler interface to jumpstart using contenteditable tags.
https://gist.github.com/3410122
Update:
Due to its increasing popularity the plugin has been adopted by Makesites.org
Development will continue from here:
Global Angular CLI version greater than local version
You just need to update the AngularCli
npm install --save-dev @angular/cli@latest
Get clicked element using jQuery on event?
A simple way is to pass the data attribute to your HTML tag.
Example:
<div data-id='tagid' class="clickElem"></div>
<script>
$(document).on("click",".appDetails", function () {
var clickedBtnID = $(this).attr('data');
alert('you clicked on button #' + clickedBtnID);
});
</script>
What is a handle in C++?
HANDLE hnd; is the same as void * ptr;
HANDLE is a typedef defined in the winnt.h file in Visual Studio (Windows):
typedef void *HANDLE;
Read more about HANDLE
How to set a variable to current date and date-1 in linux?
simple:
today="$(date '+%Y-%m-%d')"
yesterday="$(date -d yesterday '+%Y-%m-%d')"
SQL UPDATE all values in a field with appended string CONCAT not working
Solved it. Turns out the column had a limited set of characters it would accept, changed it, and now the query works fine.
Fatal error: Call to a member function query() on null
put this line in parent construct : $this->load->database();
function __construct() {
parent::__construct();
$this->load->library('lib_name');
$model=array('model_name');
$this->load->model($model);
$this->load->database();
}
this way.. it should work..
How to install python-dateutil on Windows?
You could also change your PYTHONPATH:
$ python -c 'import dateutil'
Traceback (most recent call last):
File "<string>", line 1, in <module>
ImportError: No module named dateutil
$
$ PYTHONPATH="/usr/lib/python2.6/site-packages/python_dateutil-1.5-py2.6.egg":"${PYTHONPATH}"
$ export PYTHONPATH
$ python -c 'import dateutil'
$
Where /usr/lib/python2.6/site-packages/python_dateutil-1.5-py2.6.egg is the place dateutil was installed in my box (centos using sudo yum install python-dateutil15)
How to Turn Off Showing Whitespace Characters in Visual Studio IDE
CTRL+R, CTRL+W : Toggle showing whitespace
or under the Edit Menu:
- Edit -> Advanced -> View White Space
[BTW, it also appears you are using Tabs. It's common practice to have the IDE turn Tabs into spaces (often 4), via Options.]
How to run test methods in specific order in JUnit4?
See my solution here: "Junit and java 7."
In this article I describe how to run junit tests in order - "just as in your source code". Tests will be run, in order as your test methods appears in class file.
http://intellijava.blogspot.com/2012/05/junit-and-java-7.html
But as Pascal Thivent said, this is not a good practise.
How do I set multipart in axios with react?
ok. I tried the above two ways but it didnt work for me. After trial and error i came to know that actually the file was not getting saved in 'this.state.file' variable.
fileUpload = (e) => {
let data = e.target.files
if(e.target.files[0]!=null){
this.props.UserAction.fileUpload(data[0], this.fallBackMethod)
}
}
here fileUpload is a different js file which accepts two params like this
export default (file , callback) => {
const formData = new FormData();
formData.append('fileUpload', file);
return dispatch => {
axios.put(BaseUrl.RestUrl + "ur/url", formData)
.then(response => {
callback(response.data);
}).catch(error => {
console.log("***** "+error)
});
}
}
don't forget to bind method in the constructor. Let me know if you need more help in this.
How to write a Python module/package?
Since nobody did cover this question of the OP yet:
What I wanted to do:
Make a python module install-able with "pip install ..."
Here is an absolute minimal example, showing the basic steps of preparing and uploading your package to PyPI using setuptools and twine.
This is by no means a substitute for reading at least the tutorial, there is much more to it than covered in this very basic example.
Creating the package itself is already covered by other answers here, so let us assume we have that step covered and our project structure like this:
.
+-- hellostackoverflow/
+-- __init__.py
+-- hellostackoverflow.py
In order to use setuptools for packaging, we need to add a file setup.py, this goes into the root folder of our project:
.
+-- setup.py
+-- hellostackoverflow/
+-- __init__.py
+-- hellostackoverflow.py
At the minimum, we specify the metadata for our package, our setup.py would look like this:
from setuptools import setup
setup(
name='hellostackoverflow',
version='0.0.1',
description='a pip-installable package example',
license='MIT',
packages=['hellostackoverflow'],
author='Benjamin Gerfelder',
author_email='[email protected]',
keywords=['example'],
url='https://github.com/bgse/hellostackoverflow'
)
Since we have set license='MIT', we include a copy in our project as LICENCE.txt, alongside a readme file in reStructuredText as README.rst:
.
+-- LICENCE.txt
+-- README.rst
+-- setup.py
+-- hellostackoverflow/
+-- __init__.py
+-- hellostackoverflow.py
At this point, we are ready to go to start packaging using setuptools, if we do not have it already installed, we can install it with pip:
pip install setuptools
In order to do that and create a source distribution, at our project root folder we call our setup.py from the command line, specifying we want sdist:
python setup.py sdist
This will create our distribution package and egg-info, and result in a folder structure like this, with our package in dist:
.
+-- dist/
+-- hellostackoverflow.egg-info/
+-- LICENCE.txt
+-- README.rst
+-- setup.py
+-- hellostackoverflow/
+-- __init__.py
+-- hellostackoverflow.py
At this point, we have a package we can install using pip, so from our project root (assuming you have all the naming like in this example):
pip install ./dist/hellostackoverflow-0.0.1.tar.gz
If all goes well, we can now open a Python interpreter, I would say somewhere outside our project directory to avoid any confusion, and try to use our shiny new package:
Python 3.5.2 (default, Sep 14 2017, 22:51:06)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from hellostackoverflow import hellostackoverflow
>>> hellostackoverflow.greeting()
'Hello Stack Overflow!'
Now that we have confirmed the package installs and works, we can upload it to PyPI.
Since we do not want to pollute the live repository with our experiments, we create an account for the testing repository, and install twine for the upload process:
pip install twine
Now we're almost there, with our account created we simply tell twine to upload our package, it will ask for our credentials and upload our package to the specified repository:
twine upload --repository-url https://test.pypi.org/legacy/ dist/*
We can now log into our account on the PyPI test repository and marvel at our freshly uploaded package for a while, and then grab it using pip:
pip install --index-url https://test.pypi.org/simple/ hellostackoverflow
As we can see, the basic process is not very complicated. As I said earlier, there is a lot more to it than covered here, so go ahead and read the tutorial for more in-depth explanation.
int object is not iterable?
One possible answer to OP-s question ("I wanted to find out the total by adding each digit, for eg, 110. 1 + 1 + 0 = 2. How do I do that?") is to use built-in function divmod()
num = int(input('Enter a number: ')
nums_sum = 0
while num:
num, reminder = divmod(num, 10)
nums_sum += reminder
Using Panel or PlaceHolder
A panel expands to a span (or a div), with it's content within it. A placeholder is just that, a placeholder that's replaced by whatever you put in it.
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class
Just leaving this here for future visitors:
In my case the /WEB-INF/classes directory was missing. If you are using Eclipse, make sure the .settings/org.eclipse.wst.common.component is correct (Deployment Assembly in the project settings).
In my case it was missing
<wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/resources"/>
<wb-resource deploy-path="/WEB-INF/classes" source-path="/src/test/resources"/>
This file is also a common source of errors as mentioned by Anuj (missing dependencies of other projects).
Otherwise, hopefully the other answers (or the "Problems" tab) will help you.
MySQL Update Column +1?
update TABLENAME
set COLUMNNAME = COLUMNNAME + 1
where id = 'YOURID'
Why does datetime.datetime.utcnow() not contain timezone information?
The standard Python libraries don't include any tzinfo classes (but see pep 431). I can only guess at the reasons. Personally I think it was a mistake not to include a tzinfo class for UTC, because that one is uncontroversial enough to have a standard implementation.
Edit: Although there's no implementation in the library, there is one given as an example in the tzinfo documentation.
from datetime import timedelta, tzinfo
ZERO = timedelta(0)
# A UTC class.
class UTC(tzinfo):
"""UTC"""
def utcoffset(self, dt):
return ZERO
def tzname(self, dt):
return "UTC"
def dst(self, dt):
return ZERO
utc = UTC()
To use it, to get the current time as an aware datetime object:
from datetime import datetime
now = datetime.now(utc)
There is datetime.timezone.utc in Python 3.2+:
from datetime import datetime, timezone
now = datetime.now(timezone.utc)
Remove columns from DataTable in C#
To remove all columns after the one you want, below code should work. It will remove at index 10 (remember Columns are 0 based), until the Column count is 10 or less.
DataTable dt;
int desiredSize = 10;
while (dt.Columns.Count > desiredSize)
{
dt.Columns.RemoveAt(desiredSize);
}
How to get CRON to call in the correct PATHs
On my AIX cron picks up it's environmental variables from /etc/environment ignoring what is set in the .profile.
Edit: I also checked out a couple of Linux boxes of various ages and these appear to have this file as well, so this is likely not AIX specific.
I checked this using joemaller's cron suggestion and checking the output before and after editing the PATH variable in /etc/environment.
scp files from local to remote machine error: no such file or directory
In my case I had to specify the Port Number using
scp -P 2222 username@hostip:/directory/ /localdirectory/
What is the default lifetime of a session?
Check out php.ini the value set for session.gc_maxlifetime is the ID lifetime in seconds.
I believe the default is 1440 seconds (24 mins)
http://www.php.net/manual/en/session.configuration.php
Edit: As some comments point out, the above is not entirely accurate. A wonderful explanation of why, and how to implement session lifetimes is available here:
Is there a way to provide named parameters in a function call in JavaScript?
There is another way. If you're passing an object by reference, that object's properties will appear in the function's local scope. I know this works for Safari (haven't checked other browsers) and I don't know if this feature has a name, but the below example illustrates its use.
Although in practice I don't think that this offers any functional value beyond the technique you're already using, it's a little cleaner semantically. And it still requires passing a object reference or an object literal.
function sum({ a:a, b:b}) {
console.log(a+'+'+b);
if(a==undefined) a=0;
if(b==undefined) b=0;
return (a+b);
}
// will work (returns 9 and 3 respectively)
console.log(sum({a:4,b:5}));
console.log(sum({a:3}));
// will not work (returns 0)
console.log(sum(4,5));
console.log(sum(4));
Parse JSON file using GSON
One thing that to be remembered while solving such problems is that in JSON file, a { indicates a JSONObject and a [ indicates JSONArray. If one could manage them properly, it would be very easy to accomplish the task of parsing the JSON file. The above code was really very helpful for me and I hope this content adds some meaning to the above code.
The Gson JsonReader documentation explains how to handle parsing of JsonObjects and JsonArrays:
- Within array handling methods, first call beginArray() to consume the array's opening bracket. Then create a while loop that accumulates values, terminating when hasNext() is false. Finally, read the array's closing bracket by calling endArray().
- Within object handling methods, first call beginObject() to consume the object's opening brace. Then create a while loop that assigns values to local variables based on their name. This loop should terminate when hasNext() is false. Finally, read the object's closing brace by calling endObject().
Java: Simplest way to get last word in a string
Get the last word in Kotlin:
String.substringAfterLast(" ")
Finding an elements XPath using IE Developer tool
This post suggests that you should be able to get the IE Developer Toolbar to show you the XPath for an element you click on if you turn on the "select element by click" option. http://blog.balfes.net/?p=62
Alternatively this post suggests either bookmarklets, or IE debugbar: Equivalent of Firebug's "Copy XPath" in Internet Explorer?
How to write and read java serialized objects into a file
if you serialize the whole list you also have to de-serialize the file into a list when you read it back. This means that you will inevitably load in memory a big file. It can be expensive. If you have a big file, and need to chunk it line by line (-> object by object) just proceed with your initial idea.
Serialization:
LinkedList<YourObject> listOfObjects = <something>;
try {
FileOutputStream file = new FileOutputStream(<filePath>);
ObjectOutputStream writer = new ObjectOutputStream(file);
for (YourObject obj : listOfObjects) {
writer.writeObject(obj);
}
writer.close();
file.close();
} catch (Exception ex) {
System.err.println("failed to write " + filePath + ", "+ ex);
}
De-serialization:
try {
FileInputStream file = new FileInputStream(<filePath>);
ObjectInputStream reader = new ObjectInputStream(file);
while (true) {
try {
YourObject obj = (YourObject)reader.readObject();
System.out.println(obj)
} catch (Exception ex) {
System.err.println("end of reader file ");
break;
}
}
} catch (Exception ex) {
System.err.println("failed to read " + filePath + ", "+ ex);
}
How to run a program in Atom Editor?
If you know how to launch your program from the command line then you can run it from the platformio-ide-terminal package's terminal. See platformio-ide-terminal provides an embedded terminal within the Atom text editor. So you can issue commands, including commands to run your Java program, from within it. To install this package you can use APM with the command:
$ apm install platformio-ide-terminal --no-confirm
Alternatively, you can install it from the command palette with:
- Pressing Ctrl+Shift+P. I am assuming this is the appropriate keyboard shortcut for your platform, as you have dealt ith questions about Ubuntu in the past.
- Type Install Packages and Themes.
- Search for the
platformio-ide-terminal. - Install it.
Request format is unrecognized for URL unexpectedly ending in
In my case i had an overload of function that was causing this Exception, once i changed the name of my second function it ran ok, guess web server doesnot support function overloading
Access item in a list of lists
for l in list1:
val = 50 - l[0] + l[1] - l[2]
print "val:", val
Loop through list and do operation on the sublist as you wanted.
OVER clause in Oracle
You can use it to transform some aggregate functions into analytic:
SELECT MAX(date)
FROM mytable
will return 1 row with a single maximum,
SELECT MAX(date) OVER (ORDER BY id)
FROM mytable
will return all rows with a running maximum.
Converting HTML to XML
I did found a way to convert (even bad) html into well formed XML. I started to base this on the DOM loadHTML function. However during time several issues occurred and I optimized and added patches to correct side effects.
function tryToXml($dom,$content) {
if(!$content) return false;
// xml well formed content can be loaded as xml node tree
$fragment = $dom->createDocumentFragment();
// wonderfull appendXML to add an XML string directly into the node tree!
// aappendxml will fail on a xml declaration so manually skip this when occurred
if( substr( $content,0, 5) == '<?xml' ) {
$content = substr($content,strpos($content,'>')+1);
if( strpos($content,'<') ) {
$content = substr($content,strpos($content,'<'));
}
}
// if appendXML is not working then use below htmlToXml() for nasty html correction
if(!@$fragment->appendXML( $content )) {
return $this->htmlToXml($dom,$content);
}
return $fragment;
}
// convert content into xml
// dom is only needed to prepare the xml which will be returned
function htmlToXml($dom, $content, $needEncoding=false, $bodyOnly=true) {
// no xml when html is empty
if(!$content) return false;
// real content and possibly it needs encoding
if( $needEncoding ) {
// no need to convert character encoding as loadHTML will respect the content-type (only)
$content = '<meta http-equiv="Content-Type" content="text/html;charset='.$this->encoding.'">' . $content;
}
// return a dom from the content
$domInject = new DOMDocument("1.0", "UTF-8");
$domInject->preserveWhiteSpace = false;
$domInject->formatOutput = true;
// html type
try {
@$domInject->loadHTML( $content );
} catch(Exception $e){
// do nothing and continue as it's normal that warnings will occur on nasty HTML content
}
// to check encoding: echo $dom->encoding
$this->reworkDom( $domInject );
if( $bodyOnly ) {
$fragment = $dom->createDocumentFragment();
// retrieve nodes within /html/body
foreach( $domInject->documentElement->childNodes as $elementLevel1 ) {
if( $elementLevel1->nodeName == 'body' and $elementLevel1->nodeType == XML_ELEMENT_NODE ) {
foreach( $elementLevel1->childNodes as $elementInject ) {
$fragment->insertBefore( $dom->importNode($elementInject, true) );
}
}
}
} else {
$fragment = $dom->importNode($domInject->documentElement, true);
}
return $fragment;
}
protected function reworkDom( $node, $level = 0 ) {
// start with the first child node to iterate
$nodeChild = $node->firstChild;
while ( $nodeChild ) {
$nodeNextChild = $nodeChild->nextSibling;
switch ( $nodeChild->nodeType ) {
case XML_ELEMENT_NODE:
// iterate through children element nodes
$this->reworkDom( $nodeChild, $level + 1);
break;
case XML_TEXT_NODE:
case XML_CDATA_SECTION_NODE:
// do nothing with text, cdata
break;
case XML_COMMENT_NODE:
// ensure comments to remove - sign also follows the w3c guideline
$nodeChild->nodeValue = str_replace("-","_",$nodeChild->nodeValue);
break;
case XML_DOCUMENT_TYPE_NODE: // 10: needs to be removed
case XML_PI_NODE: // 7: remove PI
$node->removeChild( $nodeChild );
$nodeChild = null; // make null to test later
break;
case XML_DOCUMENT_NODE:
// should not appear as it's always the root, just to be complete
// however generate exception!
case XML_HTML_DOCUMENT_NODE:
// should not appear as it's always the root, just to be complete
// however generate exception!
default:
throw new exception("Engine: reworkDom type not declared [".$nodeChild->nodeType. "]");
}
$nodeChild = $nodeNextChild;
} ;
}
Now this also allows to add more html pieces into one XML which I needed to use myself. In general it can be used like this:
$c='<p>test<font>two</p>';
$dom=new DOMDocument('1.0', 'UTF-8');
$n=$dom->appendChild($dom->createElement('info')); // make a root element
if( $valueXml=tryToXml($dom,$c) ) {
$n->appendChild($valueXml);
}
echo '<pre/>'. htmlentities($dom->saveXml($n)). '</pre>';
In this example '<p>test<font>two</p>' will nicely be outputed in well formed XML as '<info><p>test<font>two</font></p></info>'. The info root tag is added as it will also allow to convert '<p>one</p><p>two</p>' which is not XML as it has not one root element. However if you html does for sure have one root element then the extra root <info> tag can be skipped.
With this I'm getting real nice XML out of unstructured and even corrupted HTML!
I hope it's a bit clear and might contribute to other people to use it.
How to run sql script using SQL Server Management Studio?
This website has a concise tutorial on how to use SQL Server Management Studio. As you will see you can open a "Query Window", paste your script and run it. It does not allow you to execute scripts by using the file path. However, you can do this easily by using the command line (cmd.exe):
sqlcmd -S .\SQLExpress -i SqlScript.sql
Where SqlScript.sql is the script file name located at the current directory. See this Microsoft page for more examples
Setting the filter to an OpenFileDialog to allow the typical image formats?
This is extreme, but I built a dynamic, database-driven filter using a 2 column database table named FILE_TYPES, with field names EXTENSION and DOCTYPE:
---------------------------------
| EXTENSION | DOCTYPE |
---------------------------------
| .doc | Document |
| .docx | Document |
| .pdf | Document |
| ... | ... |
| .bmp | Image |
| .jpg | Image |
| ... | ... |
---------------------------------
Obviously I had many different types and extensions, but I'm simplifying it for this example. Here is my function:
private static string GetUploadFilter()
{
// Desired format:
// "Document files (*.doc, *.docx, *.pdf)|*.doc;*.docx;*.pdf|"
// "Image files (*.bmp, *.jpg)|*.bmp;*.jpg|"
string filter = String.Empty;
string nameFilter = String.Empty;
string extFilter = String.Empty;
// Used to get extensions
DataTable dt = new DataTable();
dt = DataLayer.Get_DataTable("SELECT * FROM FILE_TYPES ORDER BY EXTENSION");
// Used to cycle through doctype groupings ("Images", "Documents", etc.)
DataTable dtDocTypes = new DataTable();
dtDocTypes = DataLayer.Get_DataTable("SELECT DISTINCT DOCTYPE FROM FILE_TYPES ORDER BY DOCTYPE");
// For each doctype grouping...
foreach (DataRow drDocType in dtDocTypes.Rows)
{
nameFilter = drDocType["DOCTYPE"].ToString() + " files (";
// ... add its associated extensions
foreach (DataRow dr in dt.Rows)
{
if (dr["DOCTYPE"].ToString() == drDocType["DOCTYPE"].ToString())
{
nameFilter += "*" + dr["EXTENSION"].ToString() + ", ";
extFilter += "*" + dr["EXTENSION"].ToString() + ";";
}
}
// Remove endings put in place in case there was another to add, and end them with pipe characters:
nameFilter = nameFilter.TrimEnd(' ').TrimEnd(',');
nameFilter += ")|";
extFilter = extFilter.TrimEnd(';');
extFilter += "|";
// Add the name and its extensions to our main filter
filter += nameFilter + extFilter;
extFilter = ""; // clear it for next round; nameFilter will be reset to the next DOCTYPE on next pass
}
filter = filter.TrimEnd('|');
return filter;
}
private void UploadFile(string fileType, object sender)
{
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
string filter = GetUploadFilter();
dlg.Filter = filter;
if (dlg.ShowDialog().Value == true)
{
string fileName = dlg.FileName;
System.IO.FileStream fs = System.IO.File.OpenRead(fileName);
byte[] array = new byte[fs.Length];
// This will give you just the filename
fileName = fileName.Split('\\')[fileName.Split('\\').Length - 1];
...
Should yield a filter that looks like this:
How to avoid "ConcurrentModificationException" while removing elements from `ArrayList` while iterating it?
No, no, NO!
In single threated tasks you don't need to use Iterator, moreover, CopyOnWriteArrayList (due to performance hit).
Solution is much simpler: try to use canonical for loop instead of for-each loop.
According to Java copyright owners (some years ago Sun, now Oracle) for-each loop guide, it uses iterator to walk through collection and just hides it to make code looks better. But, unfortunately as we can see, it produced more problems than profits, otherwise this topic would not arise.
For example, this code will lead to java.util.ConcurrentModificationException when entering next iteration on modified ArrayList:
// process collection
for (SomeClass currElement: testList) {
SomeClass founDuplicate = findDuplicates(currElement);
if (founDuplicate != null) {
uniqueTestList.add(founDuplicate);
testList.remove(testList.indexOf(currElement));
}
}
But following code works just fine:
// process collection
for (int i = 0; i < testList.size(); i++) {
SomeClass currElement = testList.get(i);
SomeClass founDuplicate = findDuplicates(currElement);
if (founDuplicate != null) {
uniqueTestList.add(founDuplicate);
testList.remove(testList.indexOf(currElement));
i--; //to avoid skipping of shifted element
}
}
So, try to use indexing approach for iterating over collections and avoid for-each loop, as they are not equivalent! For-each loop uses some internal iterators, which check collection modification and throw ConcurrentModificationException exception. To confirm this, take a closer look at the printed stack trace when using first example that I've posted:
Exception in thread "main" java.util.ConcurrentModificationException
at java.util.AbstractList$Itr.checkForComodification(AbstractList.java:372)
at java.util.AbstractList$Itr.next(AbstractList.java:343)
at TestFail.main(TestFail.java:43)
For multithreading use corresponding multitask approaches (like synchronized keyword).
Get all child views inside LinearLayout at once
It is easier with Kotlin using for-in loop:
for (childView in ll.children) {
//childView is a child of ll
}
Here ll is id of LinearLayout defined in layout XML.
Android: Share plain text using intent (to all messaging apps)
Intent sendIntent = new Intent();
sendIntent.setAction(Intent.ACTION_SEND);
sendIntent.putExtra(Intent.EXTRA_TEXT, "This is my text to send.");
sendIntent.setType("text/plain");
Intent shareIntent = Intent.createChooser(sendIntent, null);
startActivity(shareIntent);
Capturing a form submit with jquery and .submit
Just replace the form.submit function with your own implementation:
var form = document.getElementById('form');
var formSubmit = form.submit; //save reference to original submit function
form.onsubmit = function(e)
{
formHandler();
return false;
};
var formHandler = form.submit = function()
{
alert('hi there');
formSubmit(); //optionally submit the form
};
How do I copy a range of formula values and paste them to a specific range in another sheet?
You can change
Range("B3:B65536").Copy Destination:=Sheets("DB").Range("B" & lastrow)
to
Range("B3:B65536").Copy
Sheets("DB").Range("B" & lastrow).PasteSpecial xlPasteValues
BTW, if you have xls file (excel 2003), you would get an error if your lastrow would be greater 3.
Try to use this code instead:
Sub Get_Data()
Dim lastrowDB As Long, lastrow As Long
Dim arr1, arr2, i As Integer
With Sheets("DB")
lastrowDB = .Cells(.Rows.Count, "A").End(xlUp).Row + 1
End With
arr1 = Array("B", "C", "D", "E", "F", "AH", "AI", "AJ", "J", "P", "AF")
arr2 = Array("B", "A", "C", "P", "D", "E", "G", "F", "H", "I", "J")
For i = LBound(arr1) To UBound(arr1)
With Sheets("Sheet1")
lastrow = Application.Max(3, .Cells(.Rows.Count, arr1(i)).End(xlUp).Row)
.Range(.Cells(3, arr1(i)), .Cells(lastrow, arr1(i))).Copy
Sheets("DB").Range(arr2(i) & lastrowDB).PasteSpecial xlPasteValues
End With
Next
Application.CutCopyMode = False
End Sub
Note, above code determines last non empty row on DB sheet in column A (variable lastrowDB). If you need to find lastrow for each destination column in DB sheet, use next modification:
For i = LBound(arr1) To UBound(arr1)
With Sheets("DB")
lastrowDB = .Cells(.Rows.Count, arr2(i)).End(xlUp).Row + 1
End With
' NEXT CODE
Next
You could also use next approach instead Copy/PasteSpecial. Replace
.Range(.Cells(3, arr1(i)), .Cells(lastrow, arr1(i))).Copy
Sheets("DB").Range(arr2(i) & lastrowDB).PasteSpecial xlPasteValues
with
Sheets("DB").Range(arr2(i) & lastrowDB).Resize(lastrow - 2).Value = _
.Range(.Cells(3, arr1(i)), .Cells(lastrow, arr1(i))).Value
TNS-12505: TNS:listener does not currently know of SID given in connect descriptor
I had the same issue on Windows 7. The cause was, that I had been connected to VPN using Cisco AnyConnect Secure Mobility Client.
use localStorage across subdomains
This is how:
[November 2020 Update: This solution relies on being able to set document.domain. The ability to do that has now been deprecated, unfortunately.]
For sharing between subdomains of a given superdomain (e.g. example.com), there's a technique you can use in that situation. It can be applied to localStorage, IndexedDB, SharedWorker, BroadcastChannel, etc, all of which offer shared functionality between same-origin pages, but for some reason don't respect any modification to document.domain that would let them use the superdomain as their origin directly.
(1) Pick one "main" domain to for the data to belong to: i.e. either https://example.com or https://www.example.com will hold your localStorage data. Let's say you pick https://example.com.
(2) Use localStorage normally for that chosen domain's pages.
(3) On all https://www.example.com pages (the other domain), use javascript to set document.domain = "example.com";. Then also create a hidden <iframe>, and navigate it to some page on the chosen https://example.com domain (It doesn't matter what page, as long as you can insert a very little snippet of javascript on there. If you're creating the site, just make an empty page specifically for this purpose. If you're writing an extension or a Greasemonkey-style userscript and so don't have any control over pages on the example.com server, just pick the most lightweight page you can find and insert your script into it. Some kind of "not found" page would probably be fine).
(4) The script on the hidden iframe page need only (a) set document.domain = "example.com";, and (b) notify the parent window when this is done. After that, the parent window can access the iframe window and all its objects without restriction! So the minimal iframe page is something like:
<!doctype html>
<html>
<head>
<script>
document.domain = "example.com";
window.parent.iframeReady(); // function defined & called on parent window
</script>
</head>
<body></body>
</html>
If writing a userscript, you might not want to add externally-accessible functions such as iframeReady() to your unsafeWindow, so instead a better way to notify the main window userscript might be to use a custom event:
window.parent.dispatchEvent(new CustomEvent("iframeReady"));
Which you'd detect by adding a listener for the custom "iframeReady" event to your main page's window.
(NOTE: You need to set document.domain = "example.com" even if the iframe's domain is already example.com: Assigning a value to document.domain implicitly sets the origin's port to null, and both ports must match for the iframe and its parent to be considered same-origin. See the note here: https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy#Changing_origin)
(5) Once the hidden iframe has informed its parent window that it's ready, script in the parent window can just use iframe.contentWindow.localStorage, iframe.contentWindow.indexedDB, iframe.contentWindow.BroadcastChannel, iframe.contentWindow.SharedWorker instead of window.localStorage, window.indexedDB, etc. ...and all these objects will be scoped to the chosen https://example.com origin - so they'll have the this same shared origin for all of your pages!
The most awkward part of this technique is that you have to wait for the iframe to load before proceeding. So you can't just blithely start using localStorage in your DOMContentLoaded handler, for example. Also you might want to add some error handling to detect if the hidden iframe fails to load correctly.
Obviously, you should also make sure the hidden iframe is not removed or navigated during the lifetime of your page... OTOH I don't know what the result of that would be, but very likely bad things would happen.
And, a caveat: setting/changing document.domain can be blocked using the Feature-Policy header, in which case this technique will not be usable as described.
However, there is a significantly more-complicated generalization of this technique, that can't be blocked by Feature-Policy, and that also allows entirely unrelated domains to share data, communications, and shared workers (i.e. not just subdomains off a common superdomain). @Mayank Jain already described it in their answer, namely:
The general idea is that, just as above, you create a hidden iframe to provide the correct origin for access; but instead of then just grabbing the iframe window's properties directly, you use script inside the iframe to do all of the work, and you communicate between the iframe and your main window only using postMessage() and addEventListener("message",...).
This works because postMessage() can be used even between different-origin windows. But it's also significantly more complicated because you have to pass everything through some kind of messaging infrastructure that you create between the iframe and the main window, rather than just using the localStorage, IndexedDB, etc. APIs directly in your main window's code.
Android get Current UTC time
see my answer here:
How can I get the current date and time in UTC or GMT in Java?
I've fully tested it by changing the timezones on the emulator
Java command not found on Linux
- Execute: vi ~/.bashrc OR vi ~/.bash_profile
(if above command will not allow to update the .bashrc file then you can open this file in notepad by writing command at terminal i.e. "leafpad ~/.bashrc")
- add line : export JAVA_HOME=/usr/java/jre1.6.0_24
- save the file (by using
shift + Z + Z) - source ~/.bashrc OR source ~/.bash_profile
- Execute : echo $JAVA_HOME (Output should print the path)
HTTP POST and GET using cURL in Linux
*nix provides a nice little command which makes our lives a lot easier.
GET:
with JSON:
curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://hostname/resource
with XML:
curl -H "Accept: application/xml" -H "Content-Type: application/xml" -X GET http://hostname/resource
POST:
For posting data:
curl --data "param1=value1¶m2=value2" http://hostname/resource
For file upload:
curl --form "[email protected]" http://hostname/resource
RESTful HTTP Post:
curl -X POST -d @filename http://hostname/resource
For logging into a site (auth):
curl -d "username=admin&password=admin&submit=Login" --dump-header headers http://localhost/Login
curl -L -b headers http://localhost/
Pretty-printing the curl results:
For JSON:
If you use npm and nodejs, you can install json package by running this command:
npm install -g json
Usage:
curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://hostname/resource | json
If you use pip and python, you can install pjson package by running this command:
pip install pjson
Usage:
curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://hostname/resource | pjson
If you use Python 2.6+, json tool is bundled within.
Usage:
curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://hostname/resource | python -m json.tool
If you use gem and ruby, you can install colorful_json package by running this command:
gem install colorful_json
Usage:
curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://hostname/resource | cjson
If you use apt-get (aptitude package manager of your Linux distro), you can install yajl-tools package by running this command:
sudo apt-get install yajl-tools
Usage:
curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X GET http://hostname/resource | json_reformat
For XML:
If you use *nix with Debian/Gnome envrionment, install libxml2-utils:
sudo apt-get install libxml2-utils
Usage:
curl -H "Accept: application/xml" -H "Content-Type: application/xml" -X GET http://hostname/resource | xmllint --format -
or install tidy:
sudo apt-get install tidy
Usage:
curl -H "Accept: application/xml" -H "Content-Type: application/xml" -X GET http://hostname/resource | tidy -xml -i -
Saving the curl response to a file
curl http://hostname/resource >> /path/to/your/file
or
curl http://hostname/resource -o /path/to/your/file
For detailed description of the curl command, hit:
man curl
For details about options/switches of the curl command, hit:
curl -h
Node.js - How to send data from html to express
I'd like to expand on Obertklep's answer. In his example it is an NPM module called body-parser which is doing most of the work. Where he puts req.body.name, I believe he/she is using body-parser to get the contents of the name attribute(s) received when the form is submitted.
If you do not want to use Express, use querystring which is a built-in Node module. See the answers in the link below for an example of how to use querystring.
It might help to look at this answer, which is very similar to your quest.
Spring data JPA query with parameter properties
Define the query method with signatures as follows.
@Query(select p from Person p where p.forename = :forename and p.surname = :surname)
User findByForenameAndSurname(@Param("surname") String lastname,
@Param("forename") String firstname);
}
For further details, check the Spring Data JPA reference
multiprocessing.Pool: When to use apply, apply_async or map?
Here is an overview in a table format in order to show the differences between Pool.apply, Pool.apply_async, Pool.map and Pool.map_async. When choosing one, you have to take multi-args, concurrency, blocking, and ordering into account:
| Multi-args Concurrence Blocking Ordered-results
---------------------------------------------------------------------
Pool.map | no yes yes yes
Pool.map_async | no yes no yes
Pool.apply | yes no yes no
Pool.apply_async | yes yes no no
Pool.starmap | yes yes yes yes
Pool.starmap_async| yes yes no no
Notes:
Pool.imapandPool.imap_async– lazier version of map and map_async.Pool.starmapmethod, very much similar to map method besides it acceptance of multiple arguments.Asyncmethods submit all the processes at once and retrieve the results once they are finished. Use get method to obtain the results.Pool.map(orPool.apply)methods are very much similar to Python built-in map(or apply). They block the main process until all the processes complete and return the result.
Examples:
map
Is called for a list of jobs in one time
results = pool.map(func, [1, 2, 3])
apply
Can only be called for one job
for x, y in [[1, 1], [2, 2]]:
results.append(pool.apply(func, (x, y)))
def collect_result(result):
results.append(result)
map_async
Is called for a list of jobs in one time
pool.map_async(func, jobs, callback=collect_result)
apply_async
Can only be called for one job and executes a job in the background in parallel
for x, y in [[1, 1], [2, 2]]:
pool.apply_async(worker, (x, y), callback=collect_result)
starmap
Is a variant of pool.map which support multiple arguments
pool.starmap(func, [(1, 1), (2, 1), (3, 1)])
starmap_async
A combination of starmap() and map_async() that iterates over iterable of iterables and calls func with the iterables unpacked. Returns a result object.
pool.starmap_async(calculate_worker, [(1, 1), (2, 1), (3, 1)], callback=collect_result)
Reference:
Find complete documentation here: https://docs.python.org/3/library/multiprocessing.html
jQuery each loop in table row
Use immediate children selector >:
$('#tblOne > tbody > tr')
Description: Selects all direct child elements specified by "child" of elements specified by "parent".
Client on Node.js: Uncaught ReferenceError: require is not defined
This is because require() does not exist in the browser/client-side JavaScript.
Now you're going to have to make some choices about your client-side JavaScript script management.
You have three options:
- Use the
<script>tag. - Use a CommonJS implementation. It has synchronous dependencies like Node.js
- Use an asynchronous module definition (AMD) implementation.
CommonJS client side-implementations include (most of them require a build step before you deploy):
- Browserify - You can use most Node.js modules in the browser. This is my personal favorite.
- Webpack - Does everything (bundles JavaScript code, CSS, etc.). It was made popular by the surge of React, but it is notorious for its difficult learning curve.
- Rollup - a new contender. It leverages ES6 modules and includes tree-shaking abilities (removes unused code).
You can read more about my comparison of Browserify vs (deprecated) Component.
AMD implementations include:
- RequireJS - Very popular amongst client-side JavaScript developers. It is not my taste because of its asynchronous nature.
Note, in your search for choosing which one to go with, you'll read about Bower. Bower is only for package dependencies and is unopinionated on module definitions like CommonJS and AMD.
python how to pad numpy array with zeros
Tensorflow also implemented functions for resizing/padding images tf.image.pad tf.pad.
padded_image = tf.image.pad_to_bounding_box(image, top_padding, left_padding, target_height, target_width)
padded_image = tf.pad(image, paddings, "CONSTANT")
These functions work just like other input-pipeline features of tensorflow and will work much better for machine learning applications.
How to find out what the date was 5 days ago?
I think a readable way of doing that is:
$days_ago = date('Y-m-d', strtotime('-5 days', strtotime('2008-12-02')));
How to use execvp()
In cpp, you need to pay special attention to string types when using execvp:
#include <iostream>
#include <string>
#include <cstring>
#include <stdio.h>
#include <unistd.h>
using namespace std;
const size_t MAX_ARGC = 15; // 1 command + # of arguments
char* argv[MAX_ARGC + 1]; // Needs +1 because of the null terminator at the end
// c_str() converts string to const char*, strdup converts const char* to char*
argv[0] = strdup(command.c_str());
// start filling up the arguments after the first command
size_t arg_i = 1;
while (cin && arg_i < MAX_ARGC) {
string arg;
cin >> arg;
if (arg.empty()) {
argv[arg_i] = nullptr;
break;
} else {
argv[arg_i] = strdup(arg.c_str());
}
++arg_i;
}
// Run the command with arguments
if (execvp(command.c_str(), argv) == -1) {
// Print error if command not found
cerr << "command '" << command << "' not found\n";
}
Reference: execlp?execvp?????
Convert javascript array to string
Array.prototype.toString()
The toString() method returns a string representing the specified array and its elements.
var months = ["Jan", "Feb", "Mar", "Apr"]; months.toString(); // "Jan,Feb,Mar,Apr"Syntax
arr.toString()Return value
A string representing the elements of the array.
for more information :
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toString
SmtpException: Unable to read data from the transport connection: net_io_connectionclosed
You may also have to change the "less secure apps" setting on your Gmail account. EnableSsl, use port 587 and enable "less secure apps". If you google the less secure apps part there are google help pages that will link you right to the page for your account. That was my problem but everything is working now thanks to all the answers above.
When is a timestamp (auto) updated?
Give the command SHOW CREATE TABLE whatever
Then look at the table definition.
It probably has a line like this
logtime TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
in it. DEFAULT CURRENT_TIMESTAMP means that any INSERT without an explicit time stamp setting uses the current time. Likewise, ON UPDATE CURRENT_TIMESTAMP means that any update without an explicit timestamp results in an update to the current timestamp value.
You can control this default behavior when creating your table.
Or, if the timestamp column wasn't created correctly in the first place, you can change it.
ALTER TABLE whatevertable
CHANGE whatevercolumn
whatevercolumn TIMESTAMP NOT NULL
DEFAULT CURRENT_TIMESTAMP
ON UPDATE CURRENT_TIMESTAMP;
This will cause both INSERT and UPDATE operations on the table automatically to update your timestamp column. If you want to update whatevertable without changing the timestamp, that is,
To prevent the column from updating when other columns change
then you need to issue this kind of update.
UPDATE whatevertable
SET something = 'newvalue',
whatevercolumn = whatevercolumn
WHERE someindex = 'indexvalue'
This works with TIMESTAMP and DATETIME columns. (Prior to MySQL version 5.6.5 it only worked with TIMESTAMPs) When you use TIMESTAMPs, time zones are accounted for: on a correctly configured server machine, those values are always stored in UTC and translated to local time upon retrieval.
Convert DataSet to List
Try this....modify the code as per your needs.
List<Employee> target = dt.AsEnumerable()
.Select(row => new Employee
{
Name = row.Field<string?>(0).GetValueOrDefault(),
Age= row.Field<int>(1)
}).ToList();
What are the differences between WCF and ASMX web services?
Keith Elder nicely compares ASMX to WCF here. Check it out.
Another comparison of ASMX and WCF can be found here - I don't 100% agree with all the points there, but it might give you an idea.
WCF is basically "ASMX on stereoids" - it can be all that ASMX could - plus a lot more!.
ASMX is:
- easy and simple to write and configure
- only available in IIS
- only callable from HTTP
WCF can be:
- hosted in IIS, a Windows Service, a Winforms application, a console app - you have total freedom
- used with HTTP (REST and SOAP), TCP/IP, MSMQ and many more protocols
In short: WCF is here to replace ASMX fully.
Check out the WCF Developer Center on MSDN.
Update: link seems to be dead - try this: What Is Windows Communication Foundation?
Cannot find JavaScriptSerializer in .Net 4.0
using System.Web.Script.Serialization;
is in assembly : System.Web.Extensions (System.Web.Extensions.dll)
How do you do a deep copy of an object in .NET?
You can try this
public static object DeepCopy(object obj)
{
if (obj == null)
return null;
Type type = obj.GetType();
if (type.IsValueType || type == typeof(string))
{
return obj;
}
else if (type.IsArray)
{
Type elementType = Type.GetType(
type.FullName.Replace("[]", string.Empty));
var array = obj as Array;
Array copied = Array.CreateInstance(elementType, array.Length);
for (int i = 0; i < array.Length; i++)
{
copied.SetValue(DeepCopy(array.GetValue(i)), i);
}
return Convert.ChangeType(copied, obj.GetType());
}
else if (type.IsClass)
{
object toret = Activator.CreateInstance(obj.GetType());
FieldInfo[] fields = type.GetFields(BindingFlags.Public |
BindingFlags.NonPublic | BindingFlags.Instance);
foreach (FieldInfo field in fields)
{
object fieldValue = field.GetValue(obj);
if (fieldValue == null)
continue;
field.SetValue(toret, DeepCopy(fieldValue));
}
return toret;
}
else
throw new ArgumentException("Unknown type");
}
Thanks to DetoX83 article on code project.
Why would you use Expression<Func<T>> rather than Func<T>?
I'd like to add some notes about the differences between Func<T> and Expression<Func<T>>:
Func<T>is just a normal old-school MulticastDelegate;Expression<Func<T>>is a representation of lambda expression in form of expression tree;- expression tree can be constructed through lambda expression syntax or through the API syntax;
- expression tree can be compiled to a delegate
Func<T>; - the inverse conversion is theoretically possible, but it's a kind of decompiling, there is no builtin functionality for that as it's not a straightforward process;
- expression tree can be observed/translated/modified through the
ExpressionVisitor; - the extension methods for IEnumerable operate with
Func<T>; - the extension methods for IQueryable operate with
Expression<Func<T>>.
There's an article which describes the details with code samples:
LINQ: Func<T> vs. Expression<Func<T>>.
Hope it will be helpful.
Why does "return list.sort()" return None, not the list?
The problem is here:
answer = newList.sort()
sort does not return the sorted list; rather, it sorts the list in place.
Use:
answer = sorted(newList)
How to use ConcurrentLinkedQueue?
Use poll to get the first element, and add to add a new last element. That's it, no synchronization or anything else.
Convert.ToDateTime: how to set format
If value is a string in that format and you'd like to convert it into a DateTime object, you can use DateTime.ParseExact static method:
DateTime.ParseExact(value, format, CultureInfo.CurrentCulture);
Example:
string value = "12/12";
var myDate = DateTime.ParseExact(value, "MM/yy", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None);
Console.WriteLine(myDate.ToShortDateString());
Result:
2012-12-01
Reading a text file in MATLAB line by line
You could actually use xlsread to accomplish this. After first placing your sample data above in a file 'input_file.csv', here is an example for how you can get the numeric values, text values, and the raw data in the file from the three outputs from xlsread:
>> [numData,textData,rawData] = xlsread('input_file.csv')
numData = % An array of the numeric values from the file
51.9358 4.1833
51.9354 4.1841
51.9352 4.1846
51.9343 4.1864
51.9343 4.1864
51.9341 4.1869
textData = % A cell array of strings for the text values from the file
'ABC'
'ABC'
'ABC'
'ABC'
'ABC'
'ABC'
rawData = % All the data from the file (numeric and text) in a cell array
'ABC' [51.9358] [4.1833]
'ABC' [51.9354] [4.1841]
'ABC' [51.9352] [4.1846]
'ABC' [51.9343] [4.1864]
'ABC' [51.9343] [4.1864]
'ABC' [51.9341] [4.1869]
You can then perform whatever processing you need to on the numeric data, then resave a subset of the rows of data to a new file using xlswrite. Here's an example:
index = sqrt(sum(numData.^2,2)) >= 50; % Find the rows where the point is
% at a distance of 50 or greater
% from the origin
xlswrite('output_file.csv',rawData(index,:)); % Write those rows to a new file
How do you make a deep copy of an object?
I used Dozer for cloning java objects and it's great at that , Kryo library is another great alternative.
How to open Emacs inside Bash
Emacs takes many launch options. The one that you are looking for is
emacs -nw. This will open Emacs inside the terminal disregarding the DISPLAY environment variable even if it is set.
The long form of this flag is emacs --no-window-system.
More information about Emacs launch options can be found in the manual.
Adding a Scrollable JTextArea (Java)
- Open design view
- Right click to textArea
- open surround with option
- select "...JScrollPane".
How to redirect the output of print to a TXT file
If you're on Python 2.5 or earlier, open the file and then use the file object in your redirection:
log = open("c:\\goat.txt", "w")
print >>log, "test"
If you're on Python 2.6 or 2.7, you can use print as a function:
from __future__ import print_function
log = open("c:\\goat.txt", "w")
print("test", file = log)
If you're on Python 3.0 or later, then you can omit the future import.
If you want to globally redirect your print statements, you can set sys.stdout:
import sys
sys.stdout = open("c:\\goat.txt", "w")
print ("test sys.stdout")
How to reset db in Django? I get a command 'reset' not found error
python manage.py flush
deleted old db contents,
Don't forget to create new superuser:
python manage.py createsuperuser
Convert one date format into another in PHP
This native way will help to convert any inputted format to the desired format.
$formatInput = 'd-m-Y'; //Give any format here, this would be converted into your format
$dateInput = '01-02-2018'; //date in above format
$formatOut = 'Y-m-d'; // Your format
$dateOut = DateTime::createFromFormat($formatInput, $dateInput)->format($formatOut);
Binding ng-model inside ng-repeat loop in AngularJS
<h4>Order List</h4>
<ul>
<li ng-repeat="val in filter_option.order">
<span>
<input title="{{filter_option.order_name[$index]}}" type="radio" ng-model="filter_param.order_option" ng-value="'{{val}}'" />
{{filter_option.order_name[$index]}}
</span>
<select title="" ng-model="filter_param[val]">
<option value="asc">Asc</option>
<option value="desc">Desc</option>
</select>
</li>
</ul>
A default document is not configured for the requested URL, and directory browsing is not enabled on the server
In my case, I had to install the Microsoft.Owin.Host.SystemWeb package.
I was getting the same message as you did, but then noticed I couldn't even hit a breakpoint in Startup.cs which then let me to this SO thread.
Reading in a JSON File Using Swift
Updated for Swift 3 with safest way
private func readLocalJsonFile() {
if let urlPath = Bundle.main.url(forResource: "test", withExtension: "json") {
do {
let jsonData = try Data(contentsOf: urlPath, options: .mappedIfSafe)
if let jsonDict = try JSONSerialization.jsonObject(with: jsonData, options: .mutableContainers) as? [String: AnyObject] {
if let personArray = jsonDict["person"] as? [[String: AnyObject]] {
for personDict in personArray {
for (key, value) in personDict {
print(key, value)
}
print("\n")
}
}
}
}
catch let jsonError {
print(jsonError)
}
}
}
MongoDB - Update objects in a document's array (nested updating)
For question #1, let's break it into two parts. First, increment any document that has "items.item_name" equal to "my_item_two". For this you'll have to use the positional "$" operator. Something like:
db.bar.update( {user_id : 123456 , "items.item_name" : "my_item_two" } ,
{$inc : {"items.$.price" : 1} } ,
false ,
true);
Note that this will only increment the first matched subdocument in any array (so if you have another document in the array with "item_name" equal to "my_item_two", it won't get incremented). But this might be what you want.
The second part is trickier. We can push a new item to an array without a "my_item_two" as follows:
db.bar.update( {user_id : 123456, "items.item_name" : {$ne : "my_item_two" }} ,
{$addToSet : {"items" : {'item_name' : "my_item_two" , 'price' : 1 }} } ,
false ,
true);
For your question #2, the answer is easier. To increment the total and the price of item_three in any document that contains "my_item_three," you can use the $inc operator on multiple fields at the same time. Something like:
db.bar.update( {"items.item_name" : {$ne : "my_item_three" }} ,
{$inc : {total : 1 , "items.$.price" : 1}} ,
false ,
true);
How to ssh connect through python Paramiko with ppk public key
Ok @Adam and @Kimvais were right, paramiko cannot parse .ppk files.
So the way to go (thanks to @JimB too) is to convert .ppk file to openssh private key format; this can be achieved using Puttygen as described here.
Then it's very simple getting connected with it:
import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('<hostname>', username='<username>', password='<password>', key_filename='<path/to/openssh-private-key-file>')
stdin, stdout, stderr = ssh.exec_command('ls')
print stdout.readlines()
ssh.close()
Web scraping with Java
There is also Jaunt Java Web Scraping & JSON Querying - http://jaunt-api.com
How to compare the contents of two string objects in PowerShell
You want to do $arrayOfString[0].Title -eq $myPbiject.item(0).Title
-match is for regex matching ( the second argument is a regex )
Android Intent Cannot resolve constructor
Same Error was coming with my code in Activity but not in Fragment. Showing constructor error for different line like new Intent( From.this, To.class) and new ArrayList<> etc.
Fixed using closing Android Studio and moving the repository to other location and opening the the project once again. Fixed the problem.
Seems like Android Studio building problem.
How to prevent column break within an element?
Adding;
display: inline-block;
to the child elements will prevent them being split between columns.
Print the contents of a DIV
I modified @BillPaetski answer to use querySelector, add optional CSS, remove the forced H1 tag and make title optionally specified or pulled from window. It also doesn't auto-print any more and exposes internals so they can be switched out in wrapper function or as you like.
The only two private vars are tmpWindow and tmpDoc although I believe title, css and elem access may vary it should be assumed all function arguments are private.
Code:function PrintElem(elem, title, css) {
var tmpWindow = window.open('', 'PRINT', 'height=400,width=600');
var tmpDoc = tmpWindow.document;
title = title || document.title;
css = css || "";
this.setTitle = function(newTitle) {
title = newTitle || document.title;
};
this.setCSS = function(newCSS) {
css = newCSS || "";
};
this.basicHtml5 = function(innerHTML) {
return '<!doctype html><html>'+(innerHTML || "")+'</html>';
};
this.htmlHead = function(innerHTML) {
return '<head>'+(innerHTML || "")+'</head>';
};
this.htmlTitle = function(title) {
return '<title>'+(title || "")+'</title>';
};
this.styleTag = function(innerHTML) {
return '<style>'+(innerHTML || "")+'</style>';
};
this.htmlBody = function(innerHTML) {
return '<body>'+(innerHTML || "")+'</body>';
};
this.build = function() {
tmpDoc.write(
this.basicHtml5(
this.htmlHead(
this.htmlTitle(title) + this.styleTag(css)
) + this.htmlBody(
document.querySelector(elem).innerHTML
)
)
);
tmpDoc.close(); // necessary for IE >= 10
};
this.print = function() {
tmpWindow.focus(); // necessary for IE >= 10*/
tmpWindow.print();
tmpWindow.close();
};
this.build();
return this;
}
DOMPrinter = PrintElem('#app-container');
DOMPrinter.print();
How to reference static assets within vue javascript
In order for Webpack to return the correct asset paths, you need to use require('./relative/path/to/file.jpg'), which will get processed by file-loader and returns the resolved URL.
computed: {
iconUrl () {
return require('./assets/img.png')
// The path could be '../assets/img.png', etc., which depends on where your vue file is
}
}
Find all matches in workbook using Excel VBA
Below code avoids creating infinite loop. Assume XYZ is the string which we are looking for in the workbook.
Private Sub CommandButton1_Click()
Dim Sh As Worksheet, myCounter
Dim Loc As Range
For Each Sh In ThisWorkbook.Worksheets
With Sh.UsedRange
Set Loc = .Cells.Find(What:="XYZ")
If Not Loc Is Nothing Then
MsgBox ("Value is found in " & Sh.Name)
myCounter = 1
Set Loc = .FindNext(Loc)
End If
End With
Next
If myCounter = 0 Then
MsgBox ("Value not present in this worrkbook")
End If
End Sub
Binary Data Posting with curl
You don't need --header "Content-Length: $LENGTH".
curl --request POST --data-binary "@template_entry.xml" $URL
Note that GET request does not support content body widely.
Also remember that POST request have 2 different coding schema. This is first form:
$ nc -l -p 6666 & $ curl --request POST --data-binary "@README" http://localhost:6666 POST / HTTP/1.1 User-Agent: curl/7.21.0 (x86_64-pc-linux-gnu) libcurl/7.21.0 OpenSSL/0.9.8o zlib/1.2.3.4 libidn/1.15 libssh2/1.2.6 Host: localhost:6666 Accept: */* Content-Length: 9309 Content-Type: application/x-www-form-urlencoded Expect: 100-continue .. -*- mode: rst; coding: cp1251; fill-column: 80 -*- .. rst2html.py README README.html .. contents::
You probably request this:
-F/--form name=content
(HTTP) This lets curl emulate a filled-in form in
which a user has pressed the submit button. This
causes curl to POST data using the Content- Type
multipart/form-data according to RFC2388. This
enables uploading of binary files etc. To force the
'content' part to be a file, prefix the file name
with an @ sign. To just get the content part from a
file, prefix the file name with the symbol <. The
difference between @ and < is then that @ makes a
file get attached in the post as a file upload,
while the < makes a text field and just get the
contents for that text field from a file.
Maven home (M2_HOME) not being picked up by IntelliJ IDEA
Got to this answer ? probably the answers above are to long ...
just type in :
echo "setenv M2_HOME $M2_HOME" | sudo tee -a /etc/launchd.conf
and restart your mac (thats it!)
restarting is annoying ? just use the command :
grep -E "^setenv" /etc/launchd.conf | xargs -t -L 1 launchctl
and restart IntelliJ IDEA
Import XXX cannot be resolved for Java SE standard classes
Right click on project - >BuildPath - >Configure BuildPath - >Libraries tab - >
Double click on JRE SYSTEM LIBRARY - >Then select alternate JRE
What is a method group in C#?
The ToString function has many overloads - the method group would be the group consisting of all the different overloads for that function.
How can I find the number of years between two dates?
import java.util.Calendar;
import java.util.Locale;
import static java.util.Calendar.*;
import java.util.Date;
public static int getDiffYears(Date first, Date last) {
Calendar a = getCalendar(first);
Calendar b = getCalendar(last);
int diff = b.get(YEAR) - a.get(YEAR);
if (a.get(MONTH) > b.get(MONTH) ||
(a.get(MONTH) == b.get(MONTH) && a.get(DATE) > b.get(DATE))) {
diff--;
}
return diff;
}
public static Calendar getCalendar(Date date) {
Calendar cal = Calendar.getInstance(Locale.US);
cal.setTime(date);
return cal;
}
How can I delay a method call for 1 second?
You can do this
[self performSelector:@selector(MethodToExecute) withObject:nil afterDelay:1.0 ];
Best way to make WPF ListView/GridView sort on column-header clicking?
Solution that summarizes all working parts of existing answers and comments including column header templates:
View:
<ListView x:Class="MyNamspace.MyListView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300"
ItemsSource="{Binding Items}"
GridViewColumnHeader.Click="ListViewColumnHeaderClick">
<ListView.Resources>
<Style TargetType="Grid" x:Key="HeaderGridStyle">
<Setter Property="Height" Value="20" />
</Style>
<Style TargetType="TextBlock" x:Key="HeaderTextBlockStyle">
<Setter Property="Margin" Value="5,0,0,0" />
<Setter Property="VerticalAlignment" Value="Center" />
</Style>
<Style TargetType="Path" x:Key="HeaderPathStyle">
<Setter Property="StrokeThickness" Value="1" />
<Setter Property="Fill" Value="Gray" />
<Setter Property="Width" Value="20" />
<Setter Property="HorizontalAlignment" Value="Center" />
<Setter Property="Margin" Value="5,0,5,0" />
<Setter Property="SnapsToDevicePixels" Value="True" />
</Style>
<DataTemplate x:Key="HeaderTemplateDefault">
<Grid Style="{StaticResource HeaderGridStyle}">
<TextBlock Text="{Binding }" Style="{StaticResource HeaderTextBlockStyle}" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="HeaderTemplateArrowUp">
<Grid Style="{StaticResource HeaderGridStyle}">
<Path Data="M 7,3 L 13,3 L 10,0 L 7,3" Style="{StaticResource HeaderPathStyle}" />
<TextBlock Text="{Binding }" Style="{StaticResource HeaderTextBlockStyle}" />
</Grid>
</DataTemplate>
<DataTemplate x:Key="HeaderTemplateArrowDown">
<Grid Style="{StaticResource HeaderGridStyle}">
<Path Data="M 7,0 L 10,3 L 13,0 L 7,0" Style="{StaticResource HeaderPathStyle}" />
<TextBlock Text="{Binding }" Style="{StaticResource HeaderTextBlockStyle}" />
</Grid>
</DataTemplate>
</ListView.Resources>
<ListView.View>
<GridView ColumnHeaderTemplate="{StaticResource HeaderTemplateDefault}">
<GridViewColumn Header="Name" DisplayMemberBinding="{Binding NameProperty}" />
<GridViewColumn Header="Type" Width="45" DisplayMemberBinding="{Binding TypeProperty}"/>
<!-- ... -->
</GridView>
</ListView.View>
</ListView>
Code Behinde:
public partial class MyListView : ListView
{
GridViewColumnHeader _lastHeaderClicked = null;
public MyListView()
{
InitializeComponent();
}
private void ListViewColumnHeaderClick(object sender, RoutedEventArgs e)
{
GridViewColumnHeader headerClicked = e.OriginalSource as GridViewColumnHeader;
if (headerClicked == null)
return;
if (headerClicked.Role == GridViewColumnHeaderRole.Padding)
return;
var sortingColumn = (headerClicked.Column.DisplayMemberBinding as Binding)?.Path?.Path;
if (sortingColumn == null)
return;
var direction = ApplySort(Items, sortingColumn);
if (direction == ListSortDirection.Ascending)
{
headerClicked.Column.HeaderTemplate =
Resources["HeaderTemplateArrowUp"] as DataTemplate;
}
else
{
headerClicked.Column.HeaderTemplate =
Resources["HeaderTemplateArrowDown"] as DataTemplate;
}
// Remove arrow from previously sorted header
if (_lastHeaderClicked != null && _lastHeaderClicked != headerClicked)
{
_lastHeaderClicked.Column.HeaderTemplate =
Resources["HeaderTemplateDefault"] as DataTemplate;
}
_lastHeaderClicked = headerClicked;
}
public static ListSortDirection ApplySort(ICollectionView view, string propertyName)
{
ListSortDirection direction = ListSortDirection.Ascending;
if (view.SortDescriptions.Count > 0)
{
SortDescription currentSort = view.SortDescriptions[0];
if (currentSort.PropertyName == propertyName)
{
if (currentSort.Direction == ListSortDirection.Ascending)
direction = ListSortDirection.Descending;
else
direction = ListSortDirection.Ascending;
}
view.SortDescriptions.Clear();
}
if (!string.IsNullOrEmpty(propertyName))
{
view.SortDescriptions.Add(new SortDescription(propertyName, direction));
}
return direction;
}
}
Styling text input caret
If you are using a webkit browser you can change the color of the caret by following the next CSS snippet. I'm not sure if It's possible to change the format with CSS.
input,
textarea {
font-size: 24px;
padding: 10px;
color: red;
text-shadow: 0px 0px 0px #000;
-webkit-text-fill-color: transparent;
}
input::-webkit-input-placeholder,
textarea::-webkit-input-placeholder {
color:
text-shadow: none;
-webkit-text-fill-color: initial;
}
Here is an example: http://jsfiddle.net/8k1k0awb/
How do I escape ampersands in batch files?
From a cmd:
&is escaped like this:^&(based on @Wael Dalloul's answer)%does not need to be escaped
An example:
start http://www.google.com/search?client=opera^&rls=en^&q=escape+ampersand%20and%20percentage+in+cmd^&sourceid=opera^&ie=utf-8^&oe=utf-8
From a batch file
&is escaped like this:^&(based on @Wael Dalloul's answer)%is escaped like this:%%(based on the OPs update)
An example:
start http://www.google.com/search?client=opera^&rls=en^&q=escape+ampersand%%20and%%20percentage+in+batch+file^&sourceid=opera^&ie=utf-8^&oe=utf-8
Android: Quit application when press back button
When you press back and then you finish your current activity(say A), you see a blank activity with your app logo(say B), this simply means that activity B which is shown after finishing A is still in backstack, and also activity A was started from activity B, so in activity, You should start activity A with flags as
Intent launchNextActivity;
launchNextActivity = new Intent(B.class, A.class);
launchNextActivity.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
launchNextActivity.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
launchNextActivity.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
startActivity(launchNextActivity);
Now your activity A is top on stack with no other activities of your application on the backstack.
Now in the activity A where you want to implement onBackPressed to close the app, you may do something like this,
private Boolean exit = false;
@Override
public void onBackPressed() {
if (exit) {
finish(); // finish activity
} else {
Toast.makeText(this, "Press Back again to Exit.",
Toast.LENGTH_SHORT).show();
exit = true;
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
exit = false;
}
}, 3 * 1000);
}
}
The Handler here handles accidental back presses, it simply shows a Toast, and if there is another back press within 3 seconds, it closes the application.
What order are the Junit @Before/@After called?
One potential gotcha that has bitten me before:
I like to have at most one @Before method in each test class, because order of running the @Before methods defined within a class is not guaranteed. Typically, I will call such a method setUpTest().
But, although @Before is documented as The @Before methods of superclasses will be run before those of the current class. No other ordering is defined., this only applies if each method marked with @Before has a unique name in the class hierarchy.
For example, I had the following:
public class AbstractFooTest {
@Before
public void setUpTest() {
...
}
}
public void FooTest extends AbstractFooTest {
@Before
public void setUpTest() {
...
}
}
I expected AbstractFooTest.setUpTest() to run before FooTest.setUpTest(), but only FooTest.setupTest() was executed. AbstractFooTest.setUpTest() was not called at all.
The code must be modified as follows to work:
public void FooTest extends AbstractFooTest {
@Before
public void setUpTest() {
super.setUpTest();
...
}
}
No resource identifier found for attribute '...' in package 'com.app....'
You can also use lib-auto
xmlns:app="http://schemas.android.com/apk/lib-auto"
How to get distinct results in hibernate with joins and row-based limiting (paging)?
if you want to use ORDER BY, just add:
criteria.setProjection(
Projections.distinct(
Projections.projectionList()
.add(Projections.id())
.add(Projections.property("the property that you want to ordered by"))
)
);
What is an alternative to execfile in Python 3?
While exec(open("filename").read()) is often given as an alternative to execfile("filename"), it misses important details that execfile supported.
The following function for Python3.x is as close as I could get to having the same behavior as executing a file directly. That matches running python /path/to/somefile.py.
def execfile(filepath, globals=None, locals=None):
if globals is None:
globals = {}
globals.update({
"__file__": filepath,
"__name__": "__main__",
})
with open(filepath, 'rb') as file:
exec(compile(file.read(), filepath, 'exec'), globals, locals)
# execute the file
execfile("/path/to/somefile.py")
Notes:
- Uses binary reading to avoid encoding issues
- Guaranteed to close the file (Python3.x warns about this)
- Defines
__main__, some scripts depend on this to check if they are loading as a module or not for eg.if __name__ == "__main__" - Setting
__file__is nicer for exception messages and some scripts use__file__to get the paths of other files relative to them. Takes optional globals & locals arguments, modifying them in-place as
execfiledoes - so you can access any variables defined by reading back the variables after running.Unlike Python2's
execfilethis does not modify the current namespace by default. For that you have to explicitly pass inglobals()&locals().
Navigate to another page with a button in angular 2
<button type="button" class="btn btn-primary-outline pull-right" (click)="btnClick();"><i class="fa fa-plus"></i> Add</button>
import { Router } from '@angular/router';
btnClick= function () {
this.router.navigate(['/user']);
};
What is a "method" in Python?
A method is a function that takes a class instance as its first parameter. Methods are members of classes.
class C:
def method(self, possibly, other, arguments):
pass # do something here
As you wanted to know what it specifically means in Python, one can distinguish between bound and unbound methods. In Python, all functions (and as such also methods) are objects which can be passed around and "played with". So the difference between unbound and bound methods is:
1) Bound methods
# Create an instance of C and call method()
instance = C()
print instance.method # prints '<bound method C.method of <__main__.C instance at 0x00FC50F8>>'
instance.method(1, 2, 3) # normal method call
f = instance.method
f(1, 2, 3) # method call without using the variable 'instance' explicitly
Bound methods are methods that belong to instances of a class. In this example, instance.method is bound to the instance called instance. Everytime that bound method is called, the instance is passed as first parameter automagically - which is called self by convention.
2) Unbound methods
print C.method # prints '<unbound method C.method>'
instance = C()
C.method(instance, 1, 2, 3) # this call is the same as...
f = C.method
f(instance, 1, 2, 3) # ..this one...
instance.method(1, 2, 3) # and the same as calling the bound method as you would usually do
When you access C.method (the method inside a class instead of inside an instance), you get an unbound method. If you want to call it, you have to pass the instance as first parameter because the method is not bound to any instance.
Knowing that difference, you can make use of functions/methods as objects, like passing methods around. As an example use case, imagine an API that lets you define a callback function, but you want to provide a method as callback function. No problem, just pass self.myCallbackMethod as the callback and it will automatically be called with the instance as first argument. This wouldn't be possible in static languages like C++ (or only with trickery).
Hope you got the point ;) I think that is all you should know about method basics. You could also read more about the classmethod and staticmethod decorators, but that's another topic.
How to return a complex JSON response with Node.js?
On express 3 you can use directly res.json({foo:bar})
res.json({ msgId: msg.fileName })
See the documentation
How to determine if Javascript array contains an object with an attribute that equals a given value?
Unless you want to restructure it like this:
vendors = {
Magenic: {
Name: 'Magenic',
ID: 'ABC'
},
Microsoft: {
Name: 'Microsoft',
ID: 'DEF'
} and so on...
};
to which you can do if(vendors.Magnetic)
You will have to loop
casting Object array to Integer array error
When casting is done in Java, Java compiler as well as Java run-time check whether the casting is possible or not and throws errors in case not.When casting of Object types is involved, the
instanceof test should pass in order for the assignment to go through.
In your example it results
Object[] a = new Object[1];
boolean isIntegerArr = a instanceof Integer[]
If you do a
sysout of the above line, it would return false;
So trying an instance of check before casting would help. So, to fix the error, you can either add 'instanceof' check
OR
use following line of code:
(Arrays.asList(a)).toArray(c);
Please do note that the above code would fail, if the Object array contains any entry that is other than Integer.
Angularjs: input[text] ngChange fires while the value is changing
Override the default input onChange behavior (call the function only when control loss focus and value was change)
NOTE: ngChange is not similar to the classic onChange event it firing the event while the value is changing This directive stores the value of the element when it gets the focus
On blurs it checks whether the new value has changed and if so it fires the event@param {String} - function name to be invoke when the "onChange" should be fired
@example < input my-on-change="myFunc" ng-model="model">
angular.module('app', []).directive('myOnChange', function () {
return {
restrict: 'A',
require: 'ngModel',
scope: {
myOnChange: '='
},
link: function (scope, elm, attr) {
if (attr.type === 'radio' || attr.type === 'checkbox') {
return;
}
// store value when get focus
elm.bind('focus', function () {
scope.value = elm.val();
});
// execute the event when loose focus and value was change
elm.bind('blur', function () {
var currentValue = elm.val();
if (scope.value !== currentValue) {
if (scope.myOnChange) {
scope.myOnChange();
}
}
});
}
};
});
Bind a function to Twitter Bootstrap Modal Close
Bootstrap 3 & 4
$('#myModal').on('hidden.bs.modal', function () {
// do something…
});
Bootstrap 3: getbootstrap.com/javascript/#modals-events
Bootstrap 4: getbootstrap.com/docs/4.1/components/modal/#events
Bootstrap 2.3.2
$('#myModal').on('hidden', function () {
// do something…
});
See getbootstrap.com/2.3.2/javascript.html#modals ? Events
Get the Selected value from the Drop down box in PHP
You need to set a name on the <select> tag like so:
<select name="select_catalog" id="select_catalog">
You can get it in php with this:
$_POST['select_catalog'];
Get startup type of Windows service using PowerShell
You can also use the sc tool to set it.
You can also call it from PowerShell and add additional checks if needed.
The advantage of this tool vs. PowerShell is that the sc tool can also set the start type to auto delayed.
# Get Service status
$Service = "Wecsvc"
sc.exe qc $Service
# Set Service status
$Service = "Wecsvc"
sc.exe config $Service start= delayed-auto
How to get main window handle from process id?
As an extension to Hiale's solution, you could provide a different or modified version that supports processes that have multiple main windows.
First, amend the structure to allow storing of multiple handles:
struct handle_data {
unsigned long process_id;
std::vector<HWND> handles;
};
Second, amend the callback function:
BOOL CALLBACK enum_windows_callback(HWND handle, LPARAM lParam)
{
handle_data& data = *(handle_data*)lParam;
unsigned long process_id = 0;
GetWindowThreadProcessId(handle, &process_id);
if (data.process_id != process_id || !is_main_window(handle)) {
return TRUE;
}
// change these 2 lines to allow storing of handle and loop again
data.handles.push_back(handle);
return TRUE;
}
Finally, amend the returns on the main function:
std::vector<HWD> find_main_window(unsigned long process_id)
{
handle_data data;
data.process_id = process_id;
EnumWindows(enum_windows_callback, (LPARAM)&data);
return data.handles;
}
Difference between the System.Array.CopyTo() and System.Array.Clone()
object[] myarray = new object[] { "one", 2, "three", 4, "really big number", 2324573984927361 };
//create shallow copy by CopyTo
//You have to instantiate your new array first
object[] myarray2 = new object[myarray.Length];
//but then you can specify how many members of original array you would like to copy
myarray.CopyTo(myarray2, 0);
//create shallow copy by Clone
object[] myarray1;
//here you don't need to instantiate array,
//but all elements of the original array will be copied
myarray1 = myarray.Clone() as object[];
//if not sure that we create a shalow copy lets test it
myarray[0] = 0;
Console.WriteLine(myarray[0]);// print 0
Console.WriteLine(myarray1[0]);//print "one"
Console.WriteLine(myarray2[0]);//print "one"
iptables v1.4.14: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
uname -av;
sudo apt install --reinstall (output from uname -av)
What is the difference between .NET Core and .NET Standard Class Library project types?
I hope this will help to understand the relationship between .NET Standard API surface and other .NET platforms. Each interface represents a target framework and methods represents groups of APIs available on that target framework.
namespace Analogy
{
// .NET Standard
interface INetStandard10
{
void Primitives();
void Reflection();
void Tasks();
void Xml();
void Collections();
void Linq();
}
interface INetStandard11 : INetStandard10
{
void ConcurrentCollections();
void LinqParallel();
void Compression();
void HttpClient();
}
interface INetStandard12 : INetStandard11
{
void ThreadingTimer();
}
interface INetStandard13 : INetStandard12
{
//.NET Standard 1.3 specific APIs
}
// And so on ...
// .NET Framework
interface INetFramework45 : INetStandard11
{
void FileSystem();
void Console();
void ThreadPool();
void Crypto();
void WebSockets();
void Process();
void Drawing();
void SystemWeb();
void WPF();
void WindowsForms();
void WCF();
}
interface INetFramework451 : INetFramework45, INetStandard12
{
// .NET Framework 4.5.1 specific APIs
}
interface INetFramework452 : INetFramework451, INetStandard12
{
// .NET Framework 4.5.2 specific APIs
}
interface INetFramework46 : INetFramework452, INetStandard13
{
// .NET Framework 4.6 specific APIs
}
interface INetFramework461 : INetFramework46, INetStandard14
{
// .NET Framework 4.6.1 specific APIs
}
interface INetFramework462 : INetFramework461, INetStandard15
{
// .NET Framework 4.6.2 specific APIs
}
// .NET Core
interface INetCoreApp10 : INetStandard15
{
// TODO: .NET Core 1.0 specific APIs
}
// Windows Universal Platform
interface IWindowsUniversalPlatform : INetStandard13
{
void GPS();
void Xaml();
}
// Xamarin
interface IXamarinIOS : INetStandard15
{
void AppleAPIs();
}
interface IXamarinAndroid : INetStandard15
{
void GoogleAPIs();
}
// Future platform
interface ISomeFuturePlatform : INetStandard13
{
// A future platform chooses to implement a specific .NET Standard version.
// All libraries that target that version are instantly compatible with this new
// platform
}
}
How to change Named Range Scope
You can download the free Name Manager addin developed by myself and Jan Karel Pieterse from http://www.decisionmodels.com/downloads.htm This enables many name operations that the Excel 2007 Name manager cannot handle, including changing scope of names.
In VBA:
Sub TestName()
Application.Calculation = xlManual
Names("TestName").Delete
Range("Sheet1!$A$1:$B$2").Name = "Sheet1!TestName"
Application.Calculation = xlAutomatic
End Sub
checked = "checked" vs checked = true
The element has both an attribute and a property named checked. The property determines the current state.
The attribute is a string, and the property is a boolean. When the element is created from the HTML code, the attribute is set from the markup, and the property is set depending on the value of the attribute.
If there is no value for the attribute in the markup, the attribute becomes null, but the property is always either true or false, so it becomes false.
When you set the property, you should use a boolean value:
document.getElementById('myRadio').checked = true;
If you set the attribute, you use a string:
document.getElementById('myRadio').setAttribute('checked', 'checked');
Note that setting the attribute also changes the property, but setting the property doesn't change the attribute.
Note also that whatever value you set the attribute to, the property becomes true. Even if you use an empty string or null, setting the attribute means that it's checked. Use removeAttribute to uncheck the element using the attribute:
document.getElementById('myRadio').removeAttribute('checked');
Change hash without reload in jQuery
This works for me
$('ul.questions li a').click(function(event) {
event.preventDefault();
$('.tab').hide();
window.location.hash = this.hash;
$($(this).attr('href')).fadeIn('slow');
});
Check here http://jsbin.com/edicu for a demo with almost identical code
Executing a batch script on Windows shutdown
You can create a local computer policy on Windows. See the TechNet at http://technet.microsoft.com/en-us/magazine/dd630947
- Run
gpedit.mscto open the Group Policy Editor, - Navigate to Computer Configuration | Windows Settings | Scripts (Startup/Shutdown).
Disabling Warnings generated via _CRT_SECURE_NO_DEPRECATE
For the warning by warning case, It's wise to restore it to default at some point, since you are doing it on a case by case basis.
#pragma warning(disable: 4996) /* Disable deprecation */
// Code that causes it goes here
#pragma warning(default: 4996) /* Restore default */
QComboBox - set selected item based on the item's data
You can also have a look at the method findText(const QString & text) from QComboBox; it returns the index of the element which contains the given text, (-1 if not found). The advantage of using this method is that you don't need to set the second parameter when you add an item.
Here is a little example :
/* Create the comboBox */
QComboBox *_comboBox = new QComboBox;
/* Create the ComboBox elements list (here we use QString) */
QList<QString> stringsList;
stringsList.append("Text1");
stringsList.append("Text3");
stringsList.append("Text4");
stringsList.append("Text2");
stringsList.append("Text5");
/* Populate the comboBox */
_comboBox->addItems(stringsList);
/* Create the label */
QLabel *label = new QLabel;
/* Search for "Text2" text */
int index = _comboBox->findText("Text2");
if( index == -1 )
label->setText("Text2 not found !");
else
label->setText(QString("Text2's index is ")
.append(QString::number(_comboBox->findText("Text2"))));
/* setup layout */
QVBoxLayout *layout = new QVBoxLayout(this);
layout->addWidget(_comboBox);
layout->addWidget(label);
error: expected unqualified-id before ‘.’ token //(struct)
You are trying to access the struct statically with a . instead of ::, nor are its members static. Either instantiate ReducedForm:
ReducedForm rf;
rf.iSimplifiedNumerator = 5;
or change the members to static like this:
struct ReducedForm
{
static int iSimplifiedNumerator;
static int iSimplifiedDenominator;
};
In the latter case, you must access the members with :: instead of . I highly doubt however that the latter is what you are going for ;)
How to get a substring between two strings in PHP?
Consider this function. It accepts both position number, and strings arguments:
function get_string_between($string, $start = '', $end = ''){
if (empty($start)) {
$start = 0;
}elseif (!is_numeric($start)) {
$start = strpos($string, $start) + strlen($start);
}
if (empty($end)) {
$end = strlen($string);
}elseif (!is_numeric($end)) {
$end = strpos($string, $end);
}
return substr($string, $start, ($end - $start));
}
Results:
echo get_string_between($string); // result = this is my [tag]dog[/tag]
echo get_string_between($string, 0); // result = this is my [tag]dog[/tag]
echo get_string_between($string, ''); // result = this is my [tag]dog[/tag]
echo get_string_between($string, '[tag]'); // result = dog[/tag]
echo get_string_between($string, 0, '[/tag]'); // result = this is my [tag]dog
echo get_string_between($string, '', '[/tag]'); // result = this is my [tag]dog
echo get_string_between($string, '[tag]', '[/tag]'); // result = dog
echo get_string_between($string, '[tag]', strlen($string)); // dog[/tag]
Fastest way to copy a file in Node.js
benweet's solution, but also checking the visibility of the file before copy:
function copy(from, to) {
return new Promise(function (resolve, reject) {
fs.access(from, fs.F_OK, function (error) {
if (error) {
reject(error);
} else {
var inputStream = fs.createReadStream(from);
var outputStream = fs.createWriteStream(to);
function rejectCleanup(error) {
inputStream.destroy();
outputStream.end();
reject(error);
}
inputStream.on('error', rejectCleanup);
outputStream.on('error', rejectCleanup);
outputStream.on('finish', resolve);
inputStream.pipe(outputStream);
}
});
});
}
Failed to add the host to the list of know hosts
Shouldn't known_hosts be a flat file, not a directory?
If that's not the problem, then this page on Github might be of some help. Try using SSH with the -v or -vv flag to see verbose error messages. It might give you a better idea of what's failing.
Upload folder with subfolders using S3 and the AWS console
I suggest you to use AWS CLI. As it is very easy using command line and awscli
aws s3 cp SOURCE_DIR s3://DEST_BUCKET/ --recursive
or you can use sync by
aws s3 sync SOURCE_DIR s3://DEST_BUCKET/
Remember that you have to install aws cli and configure it by using your Access Key ID and Secrect Access Key ID
pip install --upgrade --user awscli
aws configure
Get full path of a file with FileUpload Control
IE 7 and previous versions sent the full path of the uploaded file to the server related to the input type="file" field. Firefox and other modern browsers consider this to be a security flaw and do not. However, this appears to be have been fixed in IE 8.
Perhaps you should instead evaluate why you need the full path to the file as it was located on the client's system. I think it is really superfluous information that should never be posted at all. All you should be concerned with the is the file name so that you can save the file without making changes to the name.
CMake error at CMakeLists.txt:30 (project): No CMAKE_C_COMPILER could be found
I know this question is about visual studio 2015. I faced this issue with visual studio 2017. When searched on google I landed to this page. After looking at first 2,3 answers I realized this is the problem with vc++ installation. Installing the workload "Desktop development with c++" resolved the issue.
How do I set the proxy to be used by the JVM
reading an XML file and needs to download its schema
If you are counting on retrieving schemas or DTDs over the internet, you're building a slow, chatty, fragile application. What happens when that remote server hosting the file takes planned or unplanned downtime? Your app breaks. Is that OK?
See http://xml.apache.org/commons/components/resolver/resolver-article.html#s.catalog.files
URL's for schemas and the like are best thought of as unique identifiers. Not as requests to actually access that file remotely. Do some google searching on "XML catalog". An XML catalog allows you to host such resources locally, resolving the slowness, chattiness and fragility.
It's basically a permanently cached copy of the remote content. And that's OK, since the remote content will never change. If there's ever an update, it'd be at a different URL. Making the actual retrieval of the resource over the internet especially silly.
SQL - IF EXISTS UPDATE ELSE INSERT Syntax Error
INSERT INTO component_psar (tbl_id, row_nr, col_1, col_2, col_3, col_4, col_5, col_6, unit, add_info, fsar_lock)
VALUES('2', '1', '1', '1', '1', '1', '1', '1', '1', '1', 'N')
ON DUPLICATE KEY UPDATE col_1 = VALUES(col_1), col_2 = VALUES(col_2), col_3 = VALUES(col_3), col_4 = VALUES(col_4), col_5 = VALUES(col_5), col_6 = VALUES(col_6), unit = VALUES(unit), add_info = VALUES(add_info), fsar_lock = VALUES(fsar_lock)
Would work with tbl_id and row_nr having UNIQUE key.
This is the method DocJonas linked to with an example.
What's the best way to store co-ordinates (longitude/latitude, from Google Maps) in SQL Server?
I don't know the answer for SQL Server but...
In MySQL save it as FLOAT( 10, 6 )
This is the official recommendation from the Google developer documentation.
CREATE TABLE `coords` (
`lat` FLOAT( 10, 6 ) NOT NULL ,
`lng` FLOAT( 10, 6 ) NOT NULL ,
) ENGINE = MYISAM ;
What is JavaScript's highest integer value that a number can go to without losing precision?
ECMAScript 6:
Number.MAX_SAFE_INTEGER = Math.pow(2, 53)-1;
Number.MIN_SAFE_INTEGER = -Number.MAX_SAFE_INTEGER;
Do I need to pass the full path of a file in another directory to open()?
The examples to os.walk in the documentation show how to do this:
for root, dirs, filenames in os.walk(indir):
for f in filenames:
log = open(os.path.join(root, f),'r')
How did you expect the "open" function to know that the string "1" is supposed to mean "/home/des/test/1" (unless "/home/des/test" happens to be your current working directory)?
How do I create sql query for searching partial matches?
First of all, this approach won't scale in the large, you'll need a separate index from words to item (like an inverted index).
If your data is not large, you can do
SELECT DISTINCT(name) FROM mytable WHERE name LIKE '%mall%' OR description LIKE '%mall%'
using OR if you have multiple keywords.
How do I make this file.sh executable via double click?
By default, *.sh files are opened in a text editor (Xcode or TextEdit). To create a shell script that will execute in Terminal when you open it, name it with the “command” extension, e.g., file.command. By default, these are sent to Terminal, which will execute the file as a shell script.
You will also need to ensure the file is executable, e.g.:
chmod +x file.command
Without this, Terminal will refuse to execute it.
Note that the script does not have to begin with a #! prefix in this specific scenario, because Terminal specifically arranges to execute it with your default shell. (Of course, you can add a #! line if you want to customize which shell is used or if you want to ensure that you can execute it from the command line while using a different shell.)
Also note that Terminal executes the shell script without changing the working directory. You’ll need to begin your script with a cd command if you actually need it to run with a particular working directory.
Difference between window.location.href, window.location.replace and window.location.assign
These do the same thing:
window.location.assign(url);
window.location = url;
window.location.href = url;
They simply navigate to the new URL. The replace method on the other hand navigates to the URL without adding a new record to the history.
So, what you have read in those many forums is not correct. The assign method does add a new record to the history.
Reference: https://developer.mozilla.org/en-US/docs/Web/API/Window/location
ggplot2, change title size
+ theme(plot.title = element_text(size=22))
Here is the full set of things you can change in element_text:
element_text(family = NULL, face = NULL, colour = NULL, size = NULL,
hjust = NULL, vjust = NULL, angle = NULL, lineheight = NULL,
color = NULL)
Why do multiple-table joins produce duplicate rows?
Ok in this example you are getting duplicates because you are joining both D and S onto M. I assume you should be joining D.id onto S.id like below:
SELECT *
FROM M
INNER JOIN S
on M.Id = S.Id
INNER JOIN D
ON S.Id = D.Id
INNER JOIN H
ON D.Id = H.Id
Threads vs Processes in Linux
If you need to share resources, you really should use threads.
Also consider the fact that context switches between threads are much less expensive than context switches between processes.
I see no reason to explicitly go with separate processes unless you have a good reason to do so (security, proven performance tests, etc...)
Java - What does "\n" mean?
\n is add a new line.
Please note java has method System.out.println("Write text here");
Notice the difference:
Code:
System.out.println("Text 1");
System.out.println("Text 2");
Output:
Text 1
Text 2
Code:
System.out.print("Text 1");
System.out.print("Text 2");
Output:
Text 1Text 2
Convert double to Int, rounded down
If you explicitly cast double to int, the decimal part will be truncated. For example:
int x = (int) 4.97542; //gives 4 only
int x = (int) 4.23544; //gives 4 only
Moreover, you may also use Math.floor() method to round values in case you want double value in return.