How can I view an old version of a file with Git?
You can use git show
with a path from the root of the repository (./
or ../
for relative pathing):
$ git show REVISION:path/to/file
Replace REVISION
with your actual revision (could be a Git commit SHA, a tag name, a branch name, a relative commit name, or any other way of identifying a commit in Git)
For example, to view the version of file <repository-root>/src/main.c
from 4 commits ago, use:
$ git show HEAD~4:src/main.c
Git for Windows requires forward slashes even in paths relative to the current directory. For more information, check out the man page for git-show
.
How to change the port of Tomcat from 8080 to 80?
On modern linux the best approach (for me) is to use xinetd :
1) create /etc/xinet.d/tomcat-http
service http
{
disable = no
socket_type = stream
user = root
wait = no
redirect = 127.0.0.1 8080
}
2) create /etc/xinet.d/tomcat-https
service https
{
disable = no
socket_type = stream
user = root
wait = no
redirect = 127.0.0.1 8443
}
3) chkconfig xinetd on
4) /etc/init.d/xinetd start
Difference between string and char[] types in C++
Strings have helper functions and manage char arrays automatically. You can concatenate strings, for a char array you would need to copy it to a new array, strings can change their length at runtime. A char array is harder to manage than a string and certain functions may only accept a string as input, requiring you to convert the array to a string. It's better to use strings, they were made so that you don't have to use arrays. If arrays were objectively better we wouldn't have strings.
What is the simplest way to convert array to vector?
You're asking the wrong question here - instead of forcing everything into a vector ask how you can convert test to work with iterators instead of a specific container. You can provide an overload too in order to retain compatibility (and handle other containers at the same time for free):
void test(const std::vector<int>& in) {
// Iterate over vector and do whatever
}
becomes:
template <typename Iterator>
void test(Iterator begin, const Iterator end) {
// Iterate over range and do whatever
}
template <typename Container>
void test(const Container& in) {
test(std::begin(in), std::end(in));
}
Which lets you do:
int x[3]={1, 2, 3};
test(x); // Now correct
(Ideone demo)
Converting NSString to NSDictionary / JSON
Swift 3:
if let jsonString = styleDictionary as? String {
let objectData = jsonString.data(using: String.Encoding.utf8)
do {
let json = try JSONSerialization.jsonObject(with: objectData!, options: JSONSerialization.ReadingOptions.mutableContainers)
print(String(describing: json))
} catch {
// Handle error
print(error)
}
}
How to set top-left alignment for UILabel for iOS application?
As you are using the interface builder, set the constraints for your label (be sure to set the height and width as well). Then in the Size Inspector, check the height for the label. There you will want it to read >= instead of =. Then in the implementation for that view controller, set the number of lines to 0 (can also be done in IB) and set the label [label sizeToFit]; and as your text gains length, the label will grow in height and keep your text in the upper left.
How can I add a line to a file in a shell script?
To answer your original question, here's how you do it with sed:
sed -i '1icolumn1, column2, column3' testfile.csv
The "1i" command tells sed to go to line 1 and insert the text there.
The -i option causes the file to be edited "in place" and can also take an optional argument to create a backup file, for example
sed -i~ '1icolumn1, column2, column3' testfile.csv
would keep the original file in "testfile.csv~".
Changing SQL Server collation to case insensitive from case sensitive?
You can do that but the changes will affect for new data that is inserted on the database. On the long run follow as suggested above.
Also there are certain tricks you can override the collation, such as parameters for stored procedures or functions, alias data types, and variables are assigned the default collation of the database. To change the collation of an alias type, you must drop the alias and re-create it.
You can override the default collation of a literal string by using the COLLATE clause. If you do not specify a collation, the literal is assigned the database default collation. You can use DATABASEPROPERTYEX to find the current collation of the database.
You can override the server, database, or column collation by specifying a collation in the ORDER BY clause of a SELECT statement.
In Perl, how to remove ^M from a file?
Little script I have for that. A modification of it helped to filter out some other non-printable characters in cross-platform legacy files.
#!/usr/bin/perl
# run this as
# convert_dos2unix.pl < input_file > output_file
undef $/;
$_ = <>;
s/\r//ge;
print;
'mvn' is not recognized as an internal or external command, operable program or batch file
I did all of this in Windows 10 and still had a problem. In the end it turned out that
the path to the Maven home folder was not exactly what was expected in many of these answers as it turned out to be /apache-maven-3.6.3-bin/apache-maven-3.6.3. Once I corrected this for both the system variables and the PATH variable, it worked. In short, if you have set the environment variables up as directed and it still won't work, I would double check to make sure the variables really point to the exact path to the Maven home folder and the bin folder on your machine.
How to initialize all members of an array to the same value?
I see no requirements in the question, so the solution must be generic: initialization of an unspecified possibly multidimensional array built from unspecified possibly structure elements with an initial member value:
#include <string.h>
void array_init( void *start, size_t element_size, size_t elements, void *initval ){
memcpy( start, initval, element_size );
memcpy( (char*)start+element_size, start, element_size*(elements-1) );
}
// testing
#include <stdio.h>
struct s {
int a;
char b;
} array[2][3], init;
int main(){
init = (struct s){.a = 3, .b = 'x'};
array_init( array, sizeof(array[0][0]), 2*3, &init );
for( int i=0; i<2; i++ )
for( int j=0; j<3; j++ )
printf("array[%i][%i].a = %i .b = '%c'\n",i,j,array[i][j].a,array[i][j].b);
}
Result:
array[0][0].a = 3 .b = 'x'
array[0][1].a = 3 .b = 'x'
array[0][2].a = 3 .b = 'x'
array[1][0].a = 3 .b = 'x'
array[1][1].a = 3 .b = 'x'
array[1][2].a = 3 .b = 'x'
EDIT: start+element_size
changed to (char*)start+element_size
Are there constants in JavaScript?
JavaScript ES6 (re-)introduced the const
keyword which is supported in all major browsers.
Variables declared via const
cannot be re-declared or re-assigned.
Apart from that, const
behaves similar to let
.
It behaves as expected for primitive datatypes (Boolean, Null, Undefined, Number, String, Symbol):
const x = 1;
x = 2;
console.log(x); // 1 ...as expected, re-assigning fails
Attention: Be aware of the pitfalls regarding objects:
const o = {x: 1};
o = {x: 2};
console.log(o); // {x: 1} ...as expected, re-assigning fails
o.x = 2;
console.log(o); // {x: 2} !!! const does not make objects immutable!
const a = [];
a = [1];
console.log(a); // 1 ...as expected, re-assigning fails
a.push(1);
console.log(a); // [1] !!! const does not make objects immutable
If you really need an immutable and absolutely constant object: Just use const ALL_CAPS
to make your intention clear. It is a good convention to follow for all const
declarations anyway, so just rely on it.
Groovy executing shell commands
// a wrapper closure around executing a string
// can take either a string or a list of strings (for arguments with spaces)
// prints all output, complains and halts on error
def runCommand = { strList ->
assert ( strList instanceof String ||
( strList instanceof List && strList.each{ it instanceof String } ) \
)
def proc = strList.execute()
proc.in.eachLine { line -> println line }
proc.out.close()
proc.waitFor()
print "[INFO] ( "
if(strList instanceof List) {
strList.each { print "${it} " }
} else {
print strList
}
println " )"
if (proc.exitValue()) {
println "gave the following error: "
println "[ERROR] ${proc.getErrorStream()}"
}
assert !proc.exitValue()
}
Excel VBA, How to select rows based on data in a column?
Yes using Option Explicit
is a good habit. Using .Select
however is not :) it reduces the speed of the code. Also fully justify sheet names else the code will always run for the Activesheet
which might not be what you actually wanted.
Is this what you are trying?
Option Explicit
Sub Sample()
Dim lastRow As Long, i As Long
Dim CopyRange As Range
'~~> Change Sheet1 to relevant sheet name
With Sheets("Sheet1")
lastRow = .Range("A" & .Rows.Count).End(xlUp).Row
For i = 2 To lastRow
If Len(Trim(.Range("A" & i).Value)) <> 0 Then
If CopyRange Is Nothing Then
Set CopyRange = .Rows(i)
Else
Set CopyRange = Union(CopyRange, .Rows(i))
End If
Else
Exit For
End If
Next
If Not CopyRange Is Nothing Then
'~~> Change Sheet2 to relevant sheet name
CopyRange.Copy Sheets("Sheet2").Rows(1)
End If
End With
End Sub
NOTE
If if you have data from Row 2 till Row 10 and row 11 is blank and then you have data again from Row 12 then the above code will only copy data from Row 2 till Row 10
If you want to copy all rows which have data then use this code.
Option Explicit
Sub Sample()
Dim lastRow As Long, i As Long
Dim CopyRange As Range
'~~> Change Sheet1 to relevant sheet name
With Sheets("Sheet1")
lastRow = .Range("A" & .Rows.Count).End(xlUp).Row
For i = 2 To lastRow
If Len(Trim(.Range("A" & i).Value)) <> 0 Then
If CopyRange Is Nothing Then
Set CopyRange = .Rows(i)
Else
Set CopyRange = Union(CopyRange, .Rows(i))
End If
End If
Next
If Not CopyRange Is Nothing Then
'~~> Change Sheet2 to relevant sheet name
CopyRange.Copy Sheets("Sheet2").Rows(1)
End If
End With
End Sub
Hope this is what you wanted?
Sid
Insert an element at a specific index in a list and return the updated list
Most performance efficient approach
You may also insert the element using the slice indexing in the list. For example:
>>> a = [1, 2, 4]
>>> insert_at = 2 # Index at which you want to insert item
>>> b = a[:] # Created copy of list "a" as "b".
# Skip this step if you are ok with modifying the original list
>>> b[insert_at:insert_at] = [3] # Insert "3" within "b"
>>> b
[1, 2, 3, 4]
For inserting multiple elements together at a given index, all you need to do is to use a list
of multiple elements that you want to insert. For example:
>>> a = [1, 2, 4]
>>> insert_at = 2 # Index starting from which multiple elements will be inserted
# List of elements that you want to insert together at "index_at" (above) position
>>> insert_elements = [3, 5, 6]
>>> a[insert_at:insert_at] = insert_elements
>>> a # [3, 5, 6] are inserted together in `a` starting at index "2"
[1, 2, 3, 5, 6, 4]
To know more about slice indexing, you can refer: Understanding slice notation.
Note: In Python 3.x, difference of performance between slice indexing and list.index(...)
is significantly reduced and both are almost equivalent. However, in Python 2.x, this difference is quite noticeable. I have shared performance comparisons later in this answer.
Alternative using list comprehension (but very slow in terms of performance):
As an alternative, it can be achieved using list comprehension with enumerate
too. (But please don't do it this way. It is just for illustration):
>>> a = [1, 2, 4]
>>> insert_at = 2
>>> b = [y for i, x in enumerate(a) for y in ((3, x) if i == insert_at else (x, ))]
>>> b
[1, 2, 3, 4]
Performance comparison of all solutions
Here's the timeit
comparison of all the answers with list of 1000 elements on Python 3.9.1 and Python 2.7.16. Answers are listed in the order of performance for both the Python versions.
Python 3.9.1
My answer using sliced insertion - Fastest ( 2.25 µsec per loop)
python3 -m timeit -s "a = list(range(1000))" "b = a[:]; b[500:500] = [3]"
100000 loops, best of 5: 2.25 µsec per loop
Rushy Panchal's answer with most votes using list.insert(...)
- Second (2.33 µsec per loop)
python3 -m timeit -s "a = list(range(1000))" "b = a[:]; b.insert(500, 3)"
100000 loops, best of 5: 2.33 µsec per loop
ATOzTOA's accepted answer based on merge of sliced lists - Third (5.01 µsec per loop)
python3 -m timeit -s "a = list(range(1000))" "b = a[:500] + [3] + a[500:]"
50000 loops, best of 5: 5.01 µsec per loop
My answer with List Comprehension and enumerate
- Fourth (very slow with 135 µsec per loop)
python3 -m timeit -s "a = list(range(1000))" "[y for i, x in enumerate(a) for y in ((3, x) if i == 500 else (x, )) ]"
2000 loops, best of 5: 135 µsec per loop
Python 2.7.16
My answer using sliced insertion - Fastest (2.09 µsec per loop)
python -m timeit -s "a = list(range(1000))" "b = a[:]; b[500:500] = [3]"
100000 loops, best of 3: 2.09 µsec per loop
Rushy Panchal's answer with most votes using list.insert(...)
- Second (2.36 µsec per loop)
python -m timeit -s "a = list(range(1000))" "b = a[:]; b.insert(500, 3)"
100000 loops, best of 3: 2.36 µsec per loop
ATOzTOA's accepted answer based on merge of sliced lists - Third (4.44 µsec per loop)
python -m timeit -s "a = list(range(1000))" "b = a[:500] + [3] + a[500:]"
100000 loops, best of 3: 4.44 µsec per loop
My answer with List Comprehension and enumerate
- Fourth (very slow with 103 µsec per loop)
python -m timeit -s "a = list(range(1000))" "[y for i, x in enumerate(a) for y in ((3, x) if i == 500 else (x, )) ]"
10000 loops, best of 3: 103 µsec per loop
What exactly does the Access-Control-Allow-Credentials header do?
By default, CORS does not include cookies on cross-origin requests. This is different from other cross-origin techniques such as JSON-P. JSON-P always includes cookies with the request, and this behavior can lead to a class of vulnerabilities called cross-site request forgery, or CSRF.
In order to reduce the chance of CSRF vulnerabilities in CORS, CORS requires both the server and the client to acknowledge that it is ok to include cookies on requests. Doing this makes cookies an active decision, rather than something that happens passively without any control.
The client code must set the withCredentials
property on the XMLHttpRequest
to true
in order to give permission.
However, this header alone is not enough. The server must respond with the Access-Control-Allow-Credentials
header. Responding with this header to true
means that the server allows cookies (or other user credentials) to be included on cross-origin requests.
You also need to make sure your browser isn't blocking third-party cookies if you want cross-origin credentialed requests to work.
Note that regardless of whether you are making same-origin or cross-origin requests, you need to protect your site from CSRF (especially if your request includes cookies).
How to display Toast in Android?
You can customize your tost:
LayoutInflater mInflater=LayoutInflater.from(this);
View view=mInflater.inflate(R.layout.your_layout_file,null);
Toast toast=new Toast(this);
toast.setView(view);
toast.setDuration(Toast.LENGTH_LONG);
toast.show();
Or General way:
Toast.makeText(context,"Your message.", Toast.LENGTH_LONG).show();
How can I calculate the difference between two ArrayLists?
In Java, you can use the Collection
interface's removeAll
method.
// Create a couple ArrayList objects and populate them
// with some delicious fruits.
Collection firstList = new ArrayList() {{
add("apple");
add("orange");
}};
Collection secondList = new ArrayList() {{
add("apple");
add("orange");
add("banana");
add("strawberry");
}};
// Show the "before" lists
System.out.println("First List: " + firstList);
System.out.println("Second List: " + secondList);
// Remove all elements in firstList from secondList
secondList.removeAll(firstList);
// Show the "after" list
System.out.println("Result: " + secondList);
The above code will produce the following output:
First List: [apple, orange]
Second List: [apple, orange, banana, strawberry]
Result: [banana, strawberry]
How to check if JavaScript object is JSON
you can also try to parse the data and then check if you got object:
var testIfJson = JSON.parse(data);
if (typeOf testIfJson == "object")
{
//Json
}
else
{
//Not Json
}
Upload DOC or PDF using PHP
<?php
//create table
/*
--
-- Database: `mydb`
--
-- --------------------------------------------------------
--
-- Table structure for table `tbl_user_data`
--
CREATE TABLE `tbl_user_data` (
`attachment_id` int(11) NOT NULL,
`attachment` varchar(200) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
--
-- Indexes for dumped tables
--
--
-- Indexes for table `tbl_user_data`
--
ALTER TABLE `tbl_user_data`
ADD PRIMARY KEY (`attachment_id`);
--
-- AUTO_INCREMENT for dumped tables
--
--
-- AUTO_INCREMENT for table `tbl_user_data`
--
ALTER TABLE `tbl_user_data`
MODIFY `attachment_id` int(11) NOT NULL AUTO_INCREMENT;
*/
$servername = "localhost";
$username = "root";
$password = "";
// Create connection
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
if(isset($_POST['submit'])){
$fileName=$_FILES["resume"]["name"];
$fileSize=$_FILES["resume"]["size"]/1024;
$fileType=$_FILES["resume"]["type"];
$fileTmpName=$_FILES["resume"]["tmp_name"];
$statusMsg = '';
$random=rand(1111,9999);
$newFileName=$random.$fileName;
//file upload path
$targetDir = "resumeUpload/";
$fileName = basename($_FILES["resume"]["name"]);
$targetFilePath = $targetDir . $newFileName;
$fileType = pathinfo($targetFilePath,PATHINFO_EXTENSION);
if(!empty($_FILES["resume"]["name"])) {
//allow certain file formats
//$allowTypes = array('jpg','png','jpeg','gif','pdf','docx','doc');
$allowTypes = array('pdf','docx','doc');
if(in_array($fileType, $allowTypes)){
//upload file to server
if(move_uploaded_file($_FILES["resume"]["tmp_name"], $targetFilePath)){
$statusMsg = "The file ".$fileName. " has been uploaded.";
}else{
$statusMsg = "Sorry, there was an error uploading your file.";
}
}else{
$statusMsg = 'Sorry, only DOC,DOCX, & PDF files are allowed to upload.';
}
}else{
$statusMsg = 'Please select a file to upload.';
}
//display status message
echo $statusMsg;
$sql="INSERT INTO `tbl_user_data` (`attachment_id`, `attachment`) VALUES
('NULL', '$newFileName')";
if (mysqli_query($conn, $sql)) {
$last_id = mysqli_insert_id($conn);
echo "upload success";
} else {
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
}
?>
<form id="frm_upload" action="" method="post" enctype="multipart/form-data">
Upload Resume:<input type="file" name="resume" id="resume">
<button type="submit" name="submit">Apply Now</button>
</form>
//output sample[![check here for sample output][1]][1]
phantomjs not waiting for "full" page load
This is an implementation of Supr's answer. Also it uses setTimeout instead of setInterval as Mateusz Charytoniuk suggested.
Phantomjs will exit in 1000ms when there isn't any request or response.
// load the module
var webpage = require('webpage');
// get timestamp
function getTimestamp(){
// or use Date.now()
return new Date().getTime();
}
var lastTimestamp = getTimestamp();
var page = webpage.create();
page.onResourceRequested = function(request) {
// update the timestamp when there is a request
lastTimestamp = getTimestamp();
};
page.onResourceReceived = function(response) {
// update the timestamp when there is a response
lastTimestamp = getTimestamp();
};
page.open(html, function(status) {
if (status !== 'success') {
// exit if it fails to load the page
phantom.exit(1);
}
else{
// do something here
}
});
function checkReadyState() {
setTimeout(function () {
var curentTimestamp = getTimestamp();
if(curentTimestamp-lastTimestamp>1000){
// exit if there isn't request or response in 1000ms
phantom.exit();
}
else{
checkReadyState();
}
}, 100);
}
checkReadyState();
Programmatically saving image to Django ImageField
So, if you have a model with an imagefield with an upload_to attribute set, such as:
class Avatar(models.Model):
image_file = models.ImageField(upload_to=user_directory_path_avatar)
then it is reasonably easy to change the image, at least in django 3.15.
In the view, when you process the image, you can obtain the image from:
self.request.FILES['avatar']
which is an instance of type InMemoryUploadedFile, as long as your html form has the enctype set and a field for avatar...
<form method="post" class="avatarform" id="avatarform" action="{% url avatar_update_view' %}" enctype="multipart/form-data">
{% csrf_token %}
<input id="avatarUpload" class="d-none" type="file" name="avatar">
</form>
Then, setting the new image in the view is as easy as the following (where profile is the profile model for the self.request.user)
profile.avatar.image_file.save(self.request.FILES['avatar'].name, self.request.FILES['avatar'])
There is no need to save the profile.avatar, the image_field already saves, and into the correct location because of the 'upload_to' callback function.
Update Top 1 record in table sql server
It also works well ...
Update t
Set t.TIMESTAMP2 = '2013-12-12 15:40:31.593'
From
(
Select Top 1 TIMESTAMP2
From TX_Master_PCBA
Where SERIAL_NO IN ('0500030309')
Order By TIMESTAMP2 DESC
) t
Hunk #1 FAILED at 1. What's that mean?
In some cases, there is no difference in file versions, but only in indentation, spacing, line ending or line numbers.
To patch despite those differences, it's possible to use the following two arguments :
--ignore-whitespace : It ignores whitespace differences (indentation, etc).
--fuzz 3 : the "--fuzz X" option sets the maximum fuzz factor to lines. This option only applies to context and unified diffs; it ignores up to X lines while looking for the place to install a hunk. Note that a larger fuzz factor increases the odds of making a faulty patch. The default fuzz factor is 2; there is no point to setting it to more than the number of lines of context in the diff, ordinarily 3.
Don't forget to user "--dry-run" : It'll try the patch without applying it.
Example :
patch --verbose --dry-run --ignore-whitespace --fuzz 3 < /path/to/patch.patch
More informations about Fuzz :
https://www.gnu.org/software/diffutils/manual/html_node/Inexact.html
SQL DELETE with INNER JOIN
if the database is InnoDB you dont need to do joins in deletion. only
DELETE FROM spawnlist WHERE spawnlist.type = "monster";
can be used to delete the all the records that linked with foreign keys in other tables, to do that you have to first linked your tables in design time.
CREATE TABLE IF NOT EXIST spawnlist (
npc_templateid VARCHAR(20) NOT NULL PRIMARY KEY
)ENGINE=InnoDB;
CREATE TABLE IF NOT EXIST npc (
idTemplate VARCHAR(20) NOT NULL,
FOREIGN KEY (idTemplate) REFERENCES spawnlist(npc_templateid) ON DELETE CASCADE
)ENGINE=InnoDB;
if you uses MyISAM you can delete records joining like this
DELETE a,b
FROM `spawnlist` a
JOIN `npc` b
ON a.`npc_templateid` = b.`idTemplate`
WHERE a.`type` = 'monster';
in first line i have initialized the two temp tables for delet the record,
in second line i have assigned the existance table to both a and b but here i have linked both tables together with join keyword,
and i have matched the primary and foreign key for both tables that make link,
in last line i have filtered the record by field to delete.
How to add soap header in java
i was facing the same issue and solved it by removing the xmlns:wsu attribute.Try not adding it in the usernameToken.Hope this solves your issue too.
How can I render repeating React elements?
Since Array(3)
will create an un-iterable array, it must be populated to allow the usage of the map
Array method. A way to "convert"
is to destruct it inside Array-brackets, which "forces" the Array to be filled with undefined
values, same as Array(N).fill(undefined)
<table>
{ [...Array(3)].map((_, index) => <tr key={index}/>) }
</table>
Another way would be via Array fill()
:
<table>
{ Array(3).fill(<tr/>) }
</table>
?? Problem with above example is the lack of key
prop, which is a must.
(Using an iterator's index
as key
is not recommended)
Nested Nodes:
_x000D_
_x000D_
const tableSize = [3,4]
const Table = (
<table>
<tbody>
{ [...Array(tableSize[0])].map((tr, trIdx) =>
<tr key={trIdx}>
{ [...Array(tableSize[1])].map((a, tdIdx, arr) =>
<td key={trIdx + tdIdx}>
{arr.length * trIdx + tdIdx + 1}
</td>
)}
</tr>
)}
</tbody>
</table>
);
ReactDOM.render(Table, document.querySelector('main'))
_x000D_
td{ border:1px solid silver; padding:1em; }
_x000D_
<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<main></main>
_x000D_
_x000D_
_x000D_
Can we have multiple "WITH AS" in single sql - Oracle SQL
Aditya or others, can you join or match up t2 with t1 in your example, i.e. translated to my code,
with t1 as (select * from AA where FIRSTNAME like 'Kermit'),
t2 as (select * from BB B join t1 on t1.FIELD1 = B.FIELD1)
I am not clear whether only WHERE is supported for joining, or what joining approach is supported within the 2nd WITH entity. Some of the examples have the WHERE A=B down in the body of the select "below" the WITH clauses.
The error I'm getting following these WITH declarations is the identifiers (field names) in B are not recognized, down in the body of the rest of the SQL. So the WITH syntax seems to run OK, but cannot access the results from t2.
What is the difference between Forking and Cloning on GitHub?
When you say you are Forking a repository you are basically creating a copy of the repository under your GitHub ID. The main point to note here is that any changes made to the original repository will be reflected back to your forked repositories(you need to fetch and rebase). However, if you make any changes to your forked repository you will have to explicitly create a pull request to the original repository. If your pull request is approved by the administrator of the original repository, then your changes will be committed/merged with the existing original code-base. Until then, your changes will be reflected only in the copy you forked.
In short:
The Fork & Pull Model lets anyone fork an existing repository and push changes to their personal fork without requiring access be granted to the source repository. The changes must then be pulled into the source repository by the project maintainer.
Note that after forking you can clone your repository (the one under your name) locally on your machine. Make changes in it and push it to your forked repository. However, to reflect your changes in the original repository your pull request must be approved.
Couple of other interesting dicussions -
Are git forks actually git clones?
How do I update a GitHub forked repository?
Typescript ReferenceError: exports is not defined
To solve this issue, put these two lines in your index.html page.
<script>var exports = {"__esModule": true};</script>
<script type="text/javascript" src="/main.js">
Make sure to check your main.js file path.
Why does my favicon not show up?
Favicons only work when served from a web-server which sets mime-types correctly for served content. Loading from a local file might not work in chromium. Loading from an incorrectly configured web-server will not work.
Web-servers such as lighthttpd must be configured manually to set the mime type correctly.
Because of the likelihood that mimetype assignment will not work in all environments, I would suggest you use an inline base64 encoded ico file instead. This will load faster as well, as it reduces the number of http requests sent to the server.
On POSIX based systems you can base64 encode a file with the base64
command.
To create a base64 encoded ico line use the command:
$ base64 favicon.ico --wrap 0
And insert the output into the line:
<link href="data:image/x-icon;base64,HERE" rel="icon" type="image/x-icon" />
Replacing the word HERE
like so:
<link href="data:image/x-icon;base64,AAABAAEAEBAQAAEABAAoAQAAFgAAACgAAAAQAAAAIAAAAAEABAAAAAAAgAAAAAAAAAAAAAAAEAAAAAAAAAAAAAAA////AERpOgA5cCcA7vDtAF6jSABllFcAuuCvAK2trQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAFjMzMzMzNxARYzMzMzVBEEERYzMzNhERZxRGMzZxQEA2FER3cRSAgTNxgEEREIQBMzFIARERFEEzNhERARFAATMzYREBEAhBMzMzEYEBFEEzMzNhEQQRQDMzMzcRgEAAMzMzNhERgIEzMzMyERgEQDMzMzMRAEgEMzMzMxERAEEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" rel="icon" type="image/x-icon" />
Is it possible to add an HTML link in the body of a MAILTO link
Add the full link, with:
"http://"
to the beginning of a line, and most decent email clients will auto-link it either before sending, or at the other end when receiving.
For really long urls that will likely wrap due to all the parameters, wrap the link in a less than/greater than symbol. This tells the email client not to wrap the url.
e.g.
<http://www.example.com/foo.php?this=a&really=long&url=with&lots=and&lots=and&lots=of&prameters=on_it>
How to make Bootstrap carousel slider use mobile left/right swipe
I needed to add this functionality to a project I was working on recently and adding jQuery Mobile just to solve this problem seemed like overkill, so I came up with a solution and put it on github: bcSwipe (Bootstrap Carousel Swipe).
It's a lightweight jQuery plugin (~600 bytes minified vs jQuery Mobile touch events at 8kb), and it's been tested on Android and iOS.
This is how you use it:
$('.carousel').bcSwipe({ threshold: 50 });
How to get size of mysql database?
To get a result in MB:
SELECT
SUM(ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024), 2)) AS "SIZE IN MB"
FROM INFORMATION_SCHEMA.TABLES
WHERE
TABLE_SCHEMA = "SCHEMA-NAME";
To get a result in GB:
SELECT
SUM(ROUND(((DATA_LENGTH + INDEX_LENGTH) / 1024 / 1024 / 1024), 2)) AS "SIZE IN GB"
FROM INFORMATION_SCHEMA.TABLES
WHERE
TABLE_SCHEMA = "SCHEMA-NAME";
stop service in android
onDestroyed()
is wrong name for
onDestroy()
Did you make a mistake only in this question or in your code too?
Swift programmatically navigate to another view controller/scene
Swift 5
The default modal presentation style is a card. This shows the previous view controller at the top and allows the user to swipe away the presented view controller.
To retain the old style you need to modify the view controller you will be presenting like this:
newViewController.modalPresentationStyle = .fullScreen
This is the same for both programmatically created and storyboard created controllers.
Swift 3
With a programmatically created Controller
If you want to navigate to Controller created Programmatically, then do this:
let newViewController = NewViewController()
self.navigationController?.pushViewController(newViewController, animated: true)
With a StoryBoard created Controller
If you want to navigate to Controller on StoryBoard with Identifier "newViewController", then do this:
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "newViewController") as! NewViewController
self.present(newViewController, animated: true, completion: nil)
jQuery Keypress Arrow Keys
$(document).on( "keydown", keyPressed);
function keyPressed (e){
e = e || window.e;
var newchar = e.which || e.keyCode;
alert(newchar)
}
Python, how to read bytes from file and save it?
In my examples I use the 'b' flag ('wb', 'rb') when opening the files because you said you wanted to read bytes. The 'b' flag tells Python not to interpret end-of-line characters which can differ between operating systems. If you are reading text, then omit the 'b' and use 'w' and 'r' respectively.
This reads the entire file in one chunk using the "simplest" Python code. The problem with this approach is that you could run out memory when reading a large file:
ifile = open(input_filename,'rb')
ofile = open(output_filename, 'wb')
ofile.write(ifile.read())
ofile.close()
ifile.close()
This example is refined to read 1MB chunks to ensure it works for files of any size without running out of memory:
ifile = open(input_filename,'rb')
ofile = open(output_filename, 'wb')
data = ifile.read(1024*1024)
while data:
ofile.write(data)
data = ifile.read(1024*1024)
ofile.close()
ifile.close()
This example is the same as above but leverages using with to create a context. The advantage of this approach is that the file is automatically closed when exiting the context:
with open(input_filename,'rb') as ifile:
with open(output_filename, 'wb') as ofile:
data = ifile.read(1024*1024)
while data:
ofile.write(data)
data = ifile.read(1024*1024)
See the following:
How to center a checkbox in a table cell?
How about this... http://jsfiddle.net/gSaPb/
Check out my example on jsFiddle: http://jsfiddle.net/QzPGu. Code snippet:
_x000D_
_x000D_
td {
text-align: center;
/* center checkbox horizontally */
vertical-align: middle;
/* center checkbox vertically */
}
table {
border: 1px solid;
width: 200px;
}
tr {
height: 80px;
}
_x000D_
<table>
<tr>
<td>
<input type="checkbox" name="myTextEditBox" value="checked" /> checkbox
</td>
</tr>
</table>
_x000D_
_x000D_
_x000D_
libxml/tree.h no such file or directory
For Xcode 6, I had to do the following:
1) add the "libxml2.dylib" library to my project's TARGET (Build Phases -> Link Binary With Libraries)
2) add "$(SDKROOT)/usr/include/libxml2" to the Header Search Paths on the TARGET (Build Settings -> Header Search Paths)
After this, the target should build successfully.
How do I check if a Key is pressed on C++
check if a key is pressed, if yes, then do stuff
Consider 'select()', if this (reportedly Posix) function is available on your os.
'select()' uses 3 sets of bits, which you create using functions provided (see man select, FD_SET, etc). You probably only need create the input bits (for now)
from man page:
'select()' "allow a program to monitor multiple file descriptors, waiting until one or more of the file descriptors become "ready" for some class of I/O operation (e.g., input possible). A file descriptor is considered ready if it is possible to perform a corresponding I/O operation (e.g., read(2) without blocking...)"
When select is invoked:
a) the function looks at each fd identified in the sets, and if that fd state indicates you can do something (perhaps read, perhaps write), select will return and let you go do that ... 'all you got to do' is scan the bits, find the set bit, and take action on the fd associated with that bit.
The 1st set (passed into select) contains active input fd's (typically devices). Probably 1 bit in this set is all you will need. And with only 1 fd (i.e. an input from keyboard), 1 bit, this is all quite simple. With this return from select, you can 'do-stuff' (perhaps, after you have fetched the char).
b) the function also has a timeout, with which you identify how much time to await a change of the fd state. If the fd state does not change, the timeout will cause 'select()' to return with a 0. (i.e. no keyboard input) Your code can do something at this time, too, perhaps an output.
fyi - fd's are typically 0,1,2... Remembe that C uses 0 as STDIN, 1 and STDOUT.
Simple test set up: I open a terminal (separate from my console), and type the tty command in that terminal to find its id. The response is typically something like "/dev/pts/0", or 3, or 17...
Then I get an fd to use in 'select()' by using open:
// flag options are: O_RDONLY, O_WRONLY, or O_RDWR
int inFD = open( "/dev/pts/5", O_RDONLY );
It is useful to cout this value.
Here is a snippet to consider (from man select):
fd_set rfds;
struct timeval tv;
int retval;
/* Watch stdin (fd 0) to see when it has input. */
FD_ZERO(&rfds);
FD_SET(0, &rfds);
/* Wait up to five seconds. */
tv.tv_sec = 5;
tv.tv_usec = 0;
retval = select(1, &rfds, NULL, NULL, &tv);
/* Don't rely on the value of tv now! */
if (retval == -1)
perror("select()");
else if (retval)
printf("Data is available now.\n"); // i.e. doStuff()
/* FD_ISSET(0, &rfds) will be true. */
else
printf("No data within five seconds.\n"); // i.e. key not pressed
How to set up a PostgreSQL database in Django
If you are using Fedora 20, Django 1.6.5, postgresql 9.3.* and you need the psycopg2 module, do this:
yum install postgresql-devel
easy_install psycopg2
If you are like me, you may have trouble finding the well documented libpq-dev rpm... The above worked for me just now.
how to download file using AngularJS and calling MVC API?
Here you have the angularjs http request to the API that any client will have to do. Just adapt the WS url and params (if you have) to your case. It's a mixture between Naoe's answer and this one:
$http({
url: '/path/to/your/API',
method: 'POST',
params: {},
headers: {
'Content-type': 'application/pdf',
},
responseType: 'arraybuffer'
}).success(function (data, status, headers, config) {
// TODO when WS success
var file = new Blob([data], {
type: 'application/csv'
});
//trick to download store a file having its URL
var fileURL = URL.createObjectURL(file);
var a = document.createElement('a');
a.href = fileURL;
a.target = '_blank';
a.download = 'yourfilename.pdf';
document.body.appendChild(a); //create the link "a"
a.click(); //click the link "a"
document.body.removeChild(a); //remove the link "a"
}).error(function (data, status, headers, config) {
//TODO when WS error
});
Explanation of the code:
- Angularjs request a file.pdf at the URL:
/path/to/your/API
.
- Success is received on the response
- We execute a trick with JavaScript on the front-end:
- Create an html link ta:
<a>
.
- Click the hyperlink
<a>
tag, using the JS click()
function
- Remove the html
<a>
tag, after its click.
JavaScript: Check if mouse button down?
the solution isn't good.
one could "mousedown" on the document, then "mouseup" outside the browser, and on this case the browser would still be thinking the mouse is down.
the only good solution is using IE.event object.
How do you get the cursor position in a textarea?
If there is no selection, you can use the properties .selectionStart
or .selectionEnd
(with no selection they're equal).
var cursorPosition = $('#myTextarea').prop("selectionStart");
Note that this is not supported in older browsers, most notably IE8-. There you'll have to work with text ranges, but it's a complete frustration.
I believe there is a library somewhere which is dedicated to getting and setting selections/cursor positions in input elements, though. I can't recall its name, but there seem to be dozens on articles about this subject.
What does 'COLLATE SQL_Latin1_General_CP1_CI_AS' do?
This specifies the default collation for the database. Every text field that you create in tables in the database will use that collation, unless you specify a different one.
A database always has a default collation. If you don't specify any, the default collation of the SQL Server instance is used.
The name of the collation that you use shows that it uses the Latin1 code page 1, is case insensitive (CI) and accent sensitive (AS). This collation is used in the USA, so it will contain sorting rules that are used in the USA.
The collation decides how text values are compared for equality and likeness, and how they are compared when sorting. The code page is used when storing non-unicode data, e.g. varchar fields.
How can I increment a date by one day in Java?
It's simple actually.
One day contains 86400000 milliSeconds.
So first you get the current time in millis from The System by usingSystem.currentTimeMillis()
then
add the 84000000 milliSeconds and use the Date
Class to generate A date format for the milliseconds.
Example
String Today = new Date(System.currentTimeMillis()).toString();
String Today will be 2019-05-9
String Tommorow = new Date(System.currentTimeMillis() + 86400000).toString();
String Tommorow will be 2019-05-10
String DayAfterTommorow = new Date(System.currentTimeMillis() + (2 * 86400000)).toString();
String DayAfterTommorow will be 2019-05-11
Get counts of all tables in a schema
Get counts of all tables in a schema and order by desc
select 'with tmp(table_name, row_number) as (' from dual
union all
select 'select '''||table_name||''',count(*) from '||table_name||' union ' from USER_TABLES
union all
select 'select '''',0 from dual) select table_name,row_number from tmp order by row_number desc ;' from dual;
Copy the entire result and execute
Binding a generic list to a repeater - ASP.NET
Code Behind:
public class Friends
{
public string ID { get; set; }
public string Name { get; set; }
public string Image { get; set; }
}
protected void Page_Load(object sender, EventArgs e)
{
List <Friends> friendsList = new List<Friends>();
foreach (var friend in friendz)
{
friendsList.Add(
new Friends { ID = friend.id, Name = friend.name }
);
}
this.rptFriends.DataSource = friendsList;
this.rptFriends.DataBind();
}
.aspx Page
<asp:Repeater ID="rptFriends" runat="server">
<HeaderTemplate>
<table border="0" cellpadding="0" cellspacing="0">
<thead>
<tr>
<th>ID</th>
<th>Name</th>
</tr>
</thead>
<tbody>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td><%# Eval("ID") %></td>
<td><%# Eval("Name") %></td>
</tr>
</ItemTemplate>
<FooterTemplate>
</tbody>
</table>
</FooterTemplate>
</asp:Repeater>
PHP - Get key name of array value
If you have a value and want to find the key, use array_search()
like this:
$arr = array ('first' => 'a', 'second' => 'b', );
$key = array_search ('a', $arr);
$key
will now contain the key for value 'a'
(that is, 'first'
).
Is there a way to reset IIS 7.5 to factory settings?
There is one way that I have used my self. Go to Control Panel\Programs\Turn Windows features on or off
then uninstall IIS and all of its components completely. I restart windows but I'm not sure if it's required or not. Then install it again from the same path.
How to format a java.sql Timestamp for displaying?
Use String.format (or java.util.Formatter):
Timestamp timestamp = ...
String.format("%1$TD %1$TT", timestamp)
EDIT:
please see the documentation of Formatter to know what TD and TT means: click on java.util.Formatter
The first 'T' stands for:
't', 'T' date/time Prefix for date and time conversion characters.
and the character following that 'T':
'T' Time formatted for the 24-hour clock as "%tH:%tM:%tS".
'D' Date formatted as "%tm/%td/%ty".
Check if a div exists with jquery
If you are simply checking for the existence of an ID, there is no need to go into jQuery, you could simply:
if(document.getElementById("yourid") !== null)
{
}
getElementById
returns null
if it can't be found.
Reference.
If however you plan to use the jQuery object later i'd suggest:
$(document).ready(function() {
var $myDiv = $('#DivID');
if ( $myDiv.length){
//you can now reuse $myDiv here, without having to select it again.
}
});
A selector always returns a jQuery object, so there shouldn't be a need to check against null
(I'd be interested if there is an edge case where you need to check for null
- but I don't think there is).
If the selector doesn't find anything then length === 0
which is "falsy" (when converted to bool its false). So if it finds something then it should be "truthy" - so you don't need to check for > 0. Just for it's "truthyness"
How to properly stop the Thread in Java?
Simple answer:
You can stop a thread INTERNALLY in one of two common ways:
- The run method hits a return subroutine.
- Run method finishes, and returns implicitly.
You can also stop threads EXTERNALLY:
- Call
system.exit
(this kills your entire process)
- Call the thread object's
interrupt()
method *
- See if the thread has an implemented method that sounds like it would work (like
kill()
or stop()
)
*: The expectation is that this is supposed to stop a thread. However, what the thread actually does when this happens is entirely up to what the developer wrote when they created the thread implementation.
A common pattern you see with run method implementations is a while(boolean){}
, where the boolean is typically something named isRunning
, it's a member variable of its thread class, it's volatile, and typically accessible by other threads by a setter method of sorts, e.g. kill() { isRunnable=false; }
. These subroutines are nice because they allow the thread to release any resources it holds before terminating.
SQL Server converting varbinary to string
This works in both SQL 2005 and 2008:
declare @source varbinary(max);
set @source = 0x21232F297A57A5A743894A0E4A801FC3;
select cast('' as xml).value('xs:hexBinary(sql:variable("@source"))', 'varchar(max)');
Differences between dependencyManagement and dependencies in Maven
Sorry I am very late to the party.
Let me try to explain the difference using mvn dependency:tree
command
Consider the below example
Parent POM - My Project
<modules>
<module>app</module>
<module>data</module>
</modules>
<dependencies>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>19.0</version>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.9</version>
</dependency>
</dependencies>
</dependencyManagement>
Child POM - data module
<dependencies>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
</dependencies>
Child POM - app module (has no extra dependency, so leaving dependencies empty)
<dependencies>
</dependencies>
On running mvn dependency:tree
command, we get following result
Scanning for projects...
------------------------------------------------------------------------
Reactor Build Order:
MyProject
app
data
------------------------------------------------------------------------
Building MyProject 1.0-SNAPSHOT
------------------------------------------------------------------------
--- maven-dependency-plugin:2.8:tree (default-cli) @ MyProject ---
com.iamvickyav:MyProject:pom:1.0-SNAPSHOT
\- com.google.guava:guava:jar:19.0:compile
------------------------------------------------------------------------
Building app 1.0-SNAPSHOT
------------------------------------------------------------------------
--- maven-dependency-plugin:2.8:tree (default-cli) @ app ---
com.iamvickyav:app:jar:1.0-SNAPSHOT
\- com.google.guava:guava:jar:19.0:compile
------------------------------------------------------------------------
Building data 1.0-SNAPSHOT
------------------------------------------------------------------------
--- maven-dependency-plugin:2.8:tree (default-cli) @ data ---
com.iamvickyav:data:jar:1.0-SNAPSHOT
+- org.apache.commons:commons-lang3:jar:3.9:compile
\- com.google.guava:guava:jar:19.0:compile
Google guava is listed as dependency in every module (including parent), whereas the apache commons is listed as dependency only in data module (not even in parent module)
How do you truncate all tables in a database using TSQL?
The simplest way of doing this is to
- open up SQL Management Studio
- navigate to your database
- Right-click and select Tasks->Generate Scripts (pic 1)
- On the "choose Objects" screen, select the "select specific objects" option and check "tables" (pic 2)
- on the next screen, select "advanced" and then change the "Script DROP and CREATE" option to "Script DROP and CREATE" (pic 3)
- Choose to save script to a new editor window or a file and run as necessary.
this will give you a script that drops and recreates all your tables without the need to worry about debugging or whether you've included everything. While this performs more than just a truncate, the results are the same. Just keep in mind that your auto-incrementing primary keys will start at 0, as opposed to truncated tables which will remember the last value assigned. You can also execute this from code if you don't have access to Management studio on your PreProd or Production environments.
1.
2.
3.
exception.getMessage() output with class name
My guess is that you've got something in method1
which wraps one exception in another, and uses the toString()
of the nested exception as the message of the wrapper. I suggest you take a copy of your project, and remove as much as you can while keeping the problem, until you've got a short but complete program which demonstrates it - at which point either it'll be clear what's going on, or we'll be in a better position to help fix it.
Here's a short but complete program which demonstrates RuntimeException.getMessage()
behaving correctly:
public class Test {
public static void main(String[] args) {
try {
failingMethod();
} catch (Exception e) {
System.out.println("Error: " + e.getMessage());
}
}
private static void failingMethod() {
throw new RuntimeException("Just the message");
}
}
Output:
Error: Just the message
How to use an array list in Java?
This should do the trick:
String elem = (String)S.get(0);
Will return the first item in array.
Or
for(int i=0 ; i<S.size() ; i++){
System.out.println(S.get(i));
}
How to add "Maven Managed Dependencies" library in build path eclipse?
You could also consider to maven-dependency-plugin to your pom:
<plugins>
...
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<phase>process-resources</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
...
</plugins>
Than you can run "mvn package" and maven will copy all needed dependencies to your_project_path/target/your_project_name/WEB-INF/lib/ directory. From there you can copy them to your project/lib dir and add as external jars (configuring your project settings buildpath)
How to remove all whitespace from a string?
The function str_squish()
from package stringr
of tidyverse does the magic!
library(dplyr)
library(stringr)
df <- data.frame(a = c(" aZe aze s", "wxc s aze "),
b = c(" 12 12 ", "34e e4 "),
stringsAsFactors = FALSE)
df <- df %>%
rowwise() %>%
mutate_all(funs(str_squish(.))) %>%
ungroup()
df
# A tibble: 2 x 2
a b
<chr> <chr>
1 aZe aze s 12 12
2 wxc s aze 34e e4
The type or namespace name 'System' could not be found
Using VS Professional 2019, I was trying to run a downloaded solution from a Udemy class on selenium automation testing, and most of the projects had errors in the project references sections. I tried cleaning, rebuilding, closing VS. Then, in VS, when I right clicked on the solution in Solution Explorer and chose Manage Nuget Packages for Solution, there were 2 available updates: for MSTest.TestAdapter and MSTest.TestFramework, and when I installed those, the error messages on the references for all the projects went away, for the references to those, as well as for the references to System and System.Core.
Javascript | Set all values of an array
Actually, you can use this perfect approach:
let arr = Array.apply(null, Array(5)).map(() => 0);
// [0, 0, 0, 0, 0]
This code will create array and fill it with zeroes.
Or just:
let arr = new Array(5).fill(0)
Mongodb service won't start
After running the repair I was able to start the mongod proccessor but as root, which meant that service mongod start
would not work. To repair this issue, I needed to make sure that all the files inside the database folder were owned and grouped to mongod. I did this by the following:
- Check the file permissions inside your database folder
- note you need to be in your dbpath folder mine was
/var/lib/mongo
I went to cd /var/lib
- I ran
ls -l mongo
- This showed me that databases were owned by root, which is wrong. I ran the following to fix this:
chown -R mongod:mongod mongo
. This changed the owner and group of every file in the folder to mongod. (If using the mongodb package, chown -R mongodb:mongodb mongodb
)
I hope this helps someone else in the future.
dropping infinite values from dataframes in pandas?
You can use pd.DataFrame.mask
with np.isinf
. You should ensure first your dataframe series are all of type float
. Then use dropna
with your existing logic.
print(df)
col1 col2
0 -0.441406 inf
1 -0.321105 -inf
2 -0.412857 2.223047
3 -0.356610 2.513048
df = df.mask(np.isinf(df))
print(df)
col1 col2
0 -0.441406 NaN
1 -0.321105 NaN
2 -0.412857 2.223047
3 -0.356610 2.513048
How to delete the top 1000 rows from a table using Sql Server 2008?
May be better for sql2005+ to use:
DELETE TOP (1000)
FROM [MyTab]
WHERE YourConditions
For Sql2000:
DELETE FROM [MyTab]
WHERE YourIdField IN
(
SELECT TOP 1000
YourIdField
FROM [MyTab]
WHERE YourConditions
)
BUT
If you want to delete specific subset of rows instead of arbitrary subset, you should explicitly specify order to subquery:
DELETE FROM [MyTab]
WHERE YourIdField IN
(
SELECT TOP 1000
YourIdField
FROM [MyTab]
WHERE YourConditions
ORDER BY ExplicitSortOrder
)
Thanks tp @gbn for mentioning and demanding the more clear and exact answer.
What difference does .AsNoTracking() make?
The difference is that in the first case the retrieved user is not tracked by the context so when you are going to save the user back to database you must attach it and set correctly state of the user so that EF knows that it should update existing user instead of inserting a new one. In the second case you don't need to do that if you load and save the user with the same context instance because the tracking mechanism handles that for you.
Save attachments to a folder and rename them
Your question has 2 tasks to be performed. First to extract the Email attachments to a folder and saving or renaming it with a specific name.
If your search can be split to 2 searches you will get more hits. I could refer one page that explains how to save the attachment to a system folder <Link for the page to save attachments to a folder>.
Please post any page or code if you have found to save the attachment with specific name.
How to play video with AVPlayerViewController (AVKit) in Swift
Try this, definitely works for Swift 2.0
let player = AVPlayer(URL: url)
let playerController = AVPlayerViewController()
playerController.player = player
self.addChildViewController(playerController)
self.view.addSubview(playerController.view)
playerController.view.frame = self.view.frame
player.play()
C# Generics and Type Checking
Your construction completely defeats the purpose of a generic method. It's ugly on purpose because there must be a better way to achieve what you're trying to accomplish, although you haven't given us quite enough information to figure out what that is.
Why are arrays of references illegal?
Consider an array of pointers. A pointer is really an address; so when you initialize the array, you are analogously telling the computer, "allocate this block of memory to hold these X numbers (which are addresses of other items)." Then if you change one of the pointers, you are just changing what it points to; it is still a numerical address which is itself sitting in the same spot.
A reference is analogous to an alias. If you were to declare an array of references, you would basically be telling the computer, "allocate this amorphous blob of memory consisting of all these different items scattered around."
In C/C++ what's the simplest way to reverse the order of bits in a byte?
This is an old question, but nobody seems to have shown the clear easy way (the closest was edW). I used C# to test this, but there's nothing in this example that couldn't be done easily in C.
void PrintBinary(string prompt, int num, int pad = 8)
{
Debug.WriteLine($"{prompt}: {Convert.ToString(num, 2).PadLeft(pad, '0')}");
}
int ReverseBits(int num)
{
int result = 0;
int saveBits = num;
for (int i = 1; i <= 8; i++)
{
// Move the result one bit to the left
result = result << 1;
//PrintBinary("saveBits", saveBits);
// Extract the right-most bit
var nextBit = saveBits & 1;
//PrintBinary("nextBit", nextBit, 1);
// Add our extracted bit to the result
result = result | nextBit;
//PrintBinary("result", result);
// We're done with that bit, rotate it off the right
saveBits = saveBits >> 1;
//Debug.WriteLine("");
}
return result;
}
void PrintTest(int nextNumber)
{
var result = ReverseBits(nextNumber);
Debug.WriteLine("---------------------------------------");
PrintBinary("Original", nextNumber);
PrintBinary("Reverse", result);
}
void Main()
{
// Calculate the reverse for each number between 1 and 255
for (int x = 250; x < 256; x++)
PrintTest(x);
}
How do I POST form data with UTF-8 encoding by using curl?
You CAN use UTF-8 in the POST request, all you need is to specify the charset in your request.
You should use this request:
curl -X POST -H "Content-Type: application/x-www-form-urlencoded; charset=utf-8" --data-ascii "content=derinhält&date=asdf" http://myserverurl.com/api/v1/somemethod
Efficiently sorting a numpy array in descending order?
For short arrays I suggest using np.argsort()
by finding the indices of the sorted negatived array, which is slightly faster than reversing the sorted array:
In [37]: temp = np.random.randint(1,10, 10)
In [38]: %timeit np.sort(temp)[::-1]
100000 loops, best of 3: 4.65 µs per loop
In [39]: %timeit temp[np.argsort(-temp)]
100000 loops, best of 3: 3.91 µs per loop
Correctly ignore all files recursively under a specific folder except for a specific file type
Either I'm doing it wrongly, or the accepted answer does not work anymore with the current git.
I have actually found the proper solution and posted it under almost the same question here. For more details head there.
Solution:
# Ignore everything inside Resources/ directory
/Resources/**
# Except for subdirectories(won't be committed anyway if there is no committed file inside)
!/Resources/**/
# And except for *.foo files
!*.foo
Best approach to real time http streaming to HTML5 video client
This is a very common misconception. There is no live HTML5 video support (except for HLS on iOS and Mac Safari). You may be able to 'hack' it using a webm container, but I would not expect that to be universally supported. What you are looking for is included in the Media Source Extensions, where you can feed the fragments to the browser one at a time. but you will need to write some client side javascript.
gpg failed to sign the data fatal: failed to write commit object [Git 2.10.0]
I had a similar issue with the latest Git sources (2.12.2) built along with the latest sources of all its dependencies (Zlib, Bzip, cURL, PCRE, ReadLine, IDN2, iConv, Unistring, etc).
It turns out libreadline
was giving GnuPG problems:
$ gpg --version
gpg: symbol lookup error: /usr/local/lib/libreadline.so.7: undefined symbol: UP
And of course, trying to get useful information from Git with -vvv
failed, so the failure was a mystery.
To resolve the PGP failure due to ReadLine, follow the instructions at Can't update or use package manager -- gpg error:
In terminal:
ls /usr/local/lib
there was a bunch of readline libs in there (libreadline.so.BLAH-BLAH)
so i:
su
mkdir temp
mv /usr/local/lib/libreadline* temp
ldconfig
hadoop No FileSystem for scheme: file
Assuming that you are using mvn and cloudera distribution of hadoop. I'm using cdh4.6 and adding these dependencies worked for me.I think you should check the versions of hadoop and mvn dependencies.
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>2.0.0-mr1-cdh4.6.0</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>2.0.0-cdh4.6.0</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-client</artifactId>
<version>2.0.0-cdh4.6.0</version>
</dependency>
don't forget to add cloudera mvn repository.
<repository>
<id>cloudera</id>
<url>https://repository.cloudera.com/artifactory/cloudera-repos/</url>
</repository>
How to pass a type as a method parameter in Java
You could pass a Class<T>
in.
private void foo(Class<?> cls) {
if (cls == String.class) { ... }
else if (cls == int.class) { ... }
}
private void bar() {
foo(String.class);
}
Update: the OOP way depends on the functional requirement. Best bet would be an interface defining foo()
and two concrete implementations implementing foo()
and then just call foo()
on the implementation you've at hand. Another way may be a Map<Class<?>, Action>
which you could call by actions.get(cls)
. This is easily to be combined with an interface and concrete implementations: actions.get(cls).foo()
.
Hiding an Excel worksheet with VBA
This can be done in a single line, as long as the worksheet is active:
ActiveSheet.Visible = xlSheetHidden
However, you may not want to do this, especially if you use any "select" operations or you use any more ActiveSheet operations.
Rails server says port already used, how to kill that process?
For anyone stumbling across this question that is not on a Mac: assuming you know that your server is running on port 3000, you can do this in one shot by executing the following:
fuser -k 3000/tcp
But as Toby has mentioned, the implementation of fuser in Mac OS is rather primitive and this command will not work on mac.
Applying function with multiple arguments to create a new pandas column
You can go with @greenAfrican example, if it's possible for you to rewrite your function. But if you don't want to rewrite your function, you can wrap it into anonymous function inside apply, like this:
>>> def fxy(x, y):
... return x * y
>>> df['newcolumn'] = df.apply(lambda x: fxy(x['A'], x['B']), axis=1)
>>> df
A B newcolumn
0 10 20 200
1 20 30 600
2 30 10 300
Clear and reset form input fields
state={
name:"",
email:""
}
handalSubmit = () => {
after api call
let resetFrom = {}
fetch('url')
.then(function(response) {
if(response.success){
resetFrom{
name:"",
email:""
}
}
})
this.setState({...resetFrom})
}
What is SYSNAME data type in SQL Server?
Is there use case you can provide?
Anywhere you want to store an object name for use by database maintenance scripts. For example, a script purges old rows from certain tables that have a date column. It's configured with a table that gives table name, column name to filter on, and how many days of history to keep. Another script dumps certain tables to CSV files, and again is configured with a table listing the tables to dump. These configuration tables can use the sysname
type to store table and column names.
How to efficiently build a tree from a flat structure?
java version
// node
@Data
public class Node {
private Long id;
private Long parentId;
private String name;
private List<Node> children = new ArrayList<>();
}
// flat list to tree
List<Node> nodes = new ArrayList();// load nodes from db or network
Map<Long, Node> nodeMap = new HashMap();
nodes.forEach(node -> {
if (!nodeMap.containsKey(node.getId)) nodeMap.put(node.getId, node);
if (nodeMap.containsKey(node.getParentId)) {
Node parent = nodeMap.get(node.getParentId);
node.setParentId(parent.getId());
parent.getChildren().add(node);
}
});
// tree node
List<Node> treeNode = nodeMap .values().stream().filter(n -> n.getParentId() == null).collect(Collectors.toList());
Node.js spawn child process and get terminal output live
PHP-like passthru
import { spawn } from 'child_process';
export default async function passthru(exe, args, options) {
return new Promise((resolve, reject) => {
const env = Object.create(process.env);
const child = spawn(exe, args, {
...options,
env: {
...env,
...options.env,
},
});
child.stdout.setEncoding('utf8');
child.stderr.setEncoding('utf8');
child.stdout.on('data', data => console.log(data));
child.stderr.on('data', data => console.log(data));
child.on('error', error => reject(error));
child.on('close', exitCode => {
console.log('Exit code:', exitCode);
resolve(exitCode);
});
});
}
Usage
const exitCode = await passthru('ls', ['-al'], { cwd: '/var/www/html' })
How to change background and text colors in Sublime Text 3
I had the same issue. Sublime3 no longer shows all of the installed packages when you choose Show Packages from the Preferences Menu.
To customise a colour scheme do the following (UNIX):
- Locate your SublimeText packages directory under the directory which SublimeText is installed in (in my setup this was /opt/sublime/Packages)
- Open "Color Scheme - Default.sublime-package"
- Choose the colour scheme which is closest to your requirements and copy it
- From Sublime Text choose Preferences - Browse Packages - User
- Paste the colour scheme you copied earlier here and rename it. It should now show up on your "Preferences - Color Scheme" menu under "User"
- Follow the instructions at the link you previously mentioned to make the changes you require (Sublime 2 -changing background color based on file type?)
--- EDIT ---
For Mac OS X the themes are stored in zipped files so although the preferences file shows them as being in Packages/Color Scheme - Default/ they don't appear in that directory unless you extract them.
- They can be extracted using the Package Resource Viewer (See this answer for how to install and use the Package Resource Viewer).
- Search for Color Scheme in the Package Extractor (should give options for Color Scheme Default and Color Scheme legacy)
- Extract the one you want. It will now be available at users/UserName/Library/Application Support/Sublime Text 3/Packages/Color Scheme - Default (or Legacy)
- Make a copy of the scheme you want to modify, edit as needed and save it
- Add or change the line in user preferences which points to the color scheme
for example
"color_scheme": "Packages/Color Scheme - Legacy/myTheme.tmTheme"
remote: repository not found fatal: not found
I tried pretty much everything suggested in the answers above. Unfortunately, nothing worked. Then I signout out of my Github account on VS Code and signed in again. Added the remote origin with the following command.
git remote add origin https://github.com/pete/first_app.git
And it was working.
Downloading and unzipping a .zip file without writing to disk
Vishal's example, however great, confuses when it comes to the file name, and I do not see the merit of redefing 'zipfile'.
Here is my example that downloads a zip that contains some files, one of which is a csv file that I subsequently read into a pandas DataFrame:
from StringIO import StringIO
from zipfile import ZipFile
from urllib import urlopen
import pandas
url = urlopen("https://www.federalreserve.gov/apps/mdrm/pdf/MDRM.zip")
zf = ZipFile(StringIO(url.read()))
for item in zf.namelist():
print("File in zip: "+ item)
# find the first matching csv file in the zip:
match = [s for s in zf.namelist() if ".csv" in s][0]
# the first line of the file contains a string - that line shall de ignored, hence skiprows
df = pandas.read_csv(zf.open(match), low_memory=False, skiprows=[0])
(Note, I use Python 2.7.13)
This is the exact solution that worked for me. I just tweaked it a little bit for Python 3 version by removing StringIO and adding IO library
Python 3 Version
from io import BytesIO
from zipfile import ZipFile
import pandas
import requests
url = "https://www.nseindia.com/content/indices/mcwb_jun19.zip"
content = requests.get(url)
zf = ZipFile(BytesIO(content.content))
for item in zf.namelist():
print("File in zip: "+ item)
# find the first matching csv file in the zip:
match = [s for s in zf.namelist() if ".csv" in s][0]
# the first line of the file contains a string - that line shall de ignored, hence skiprows
df = pandas.read_csv(zf.open(match), low_memory=False, skiprows=[0])
How do you post data with a link
If you want to pass the data using POST instead of GET, you can do it using a combination of PHP and JavaScript, like this:
function formSubmit(house_number)
{
document.forms[0].house_number.value = house_number;
document.forms[0].submit();
}
Then in PHP you loop through the house-numbers, and create links to the JavaScript function, like this:
<form action="house.php" method="POST">
<input type="hidden" name="house_number" value="-1">
<?php
foreach ($houses as $id => name)
{
echo "<a href=\"javascript:formSubmit($id);\">$name</a>\n";
}
?>
</form>
That way you just have one form whose hidden variable(s) get modified according to which link you click on. Then JavasScript submits the form.
Text file with 0D 0D 0A line breaks
The CRCRLF is known as result of a Windows XP notepad word wrap bug.
For future reference, here's an extract of relevance from the linked blog:
When you press the Enter key on Windows computers, two characters are actually stored: a carriage return (CR) and a line feed (LF). The operating system always interprets the character sequence CR LF the same way as the Enter key: it moves to the next line. However when there are extra CR or LF characters on their own, this can sometimes cause problems.
There is a bug in the Windows XP version of Notepad that can cause extra CR characters to be stored in the display window. The bug happens in the following situation:
If you have the word wrap option turned on and the display window contains long lines that wrap around, then saving the file causes Notepad to insert the characters CR CR LF at each wrap point in the display window, but not in the saved file.
The CR CR LF characters can cause oddities if you copy and paste them into other programs. They also prevent Notepad from properly re-wrapping the lines if you resize the Notepad window.
You can remove the CR CR LF characters by turning off the word wrap feature, then turning it back on if desired. However, the cursor is repositioned at the beginning of the display window when you do this.
MySQL Workbench Dark Theme
For disabling Dark mode in MySQL workbench on mac:
Open terminal use mentioned command:
defaults write com.oracle.workbench.MySQLWorkbench NSRequiresAquaSystemAppearance -bool yes
For Enabling Dark mode in MySQL workbench on mac:
Open terminal:
defaults write com.oracle.workbench.MySQLWorkbench NSRequiresAquaSystemAppearance -bool no
Reading rows from a CSV file in Python
Reading it columnwise is harder?
Anyway this reads the line and stores the values in a list:
for line in open("csvfile.csv"):
csv_row = line.split() #returns a list ["1","50","60"]
Modern solution:
# pip install pandas
import pandas as pd
df = pd.read_table("csvfile.csv", sep=" ")
Android turn On/Off WiFi HotSpot programmatically
Here's the complete solution if you want to implement the wifi hotspot feature programmatically in your android app.
SOLUTION FOR API < 26:
For devices < API 26. There is no public API by Android for this purpose. So, in order to work with those APIs you've to access private APIs through reflection. It is not recommended but if you've no other options left, then here's a trick.
First of all, you need to have this permission in your manifest,
<uses-permission
android:name="android.permission.WRITE_SETTINGS"
tools:ignore="ProtectedPermissions"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
Here's how you can ask it on run-time:
private boolean showWritePermissionSettings() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
&& Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
if (!Settings.System.canWrite(this)) {
Log.v("DANG", " " + !Settings.System.canWrite(this));
Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_WRITE_SETTINGS);
intent.setData(Uri.parse("package:" + this.getPackageName()));
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
this.startActivity(intent);
return false;
}
}
return true; //Permission already given
}
You can then access the setWifiEnabled
method through reflection. This returns true if the action you asked for is being process correctly i.e. enabling/disabling hotspot.
public boolean setWifiEnabled(WifiConfiguration wifiConfig, boolean enabled) {
WifiManager wifiManager;
try {
if (enabled) { //disables wifi hotspot if it's already enabled
wifiManager.setWifiEnabled(false);
}
Method method = wifiManager.getClass()
.getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
return (Boolean) method.invoke(wifiManager, wifiConfig, enabled);
} catch (Exception e) {
Log.e(this.getClass().toString(), "", e);
return false;
}
}
You can also get the wificonfiguration of your hotspot through reflection. I've answered that method for this question on StackOverflow.
P.S: If you don't want to turn on hotspot programmatically, you can start this intent and open the wifi settings screen for user to turn it on manually.
SOLUTION FOR API >= 26:
Finally, android released an official API for versions >= Oreo. You can just use the public exposed API by android i.e. startLocalOnlyHotspot
It turns on a local hotspot without internet access. Which thus can be used to host a server or transfer files.
It requires Manifest.permission.CHANGE_WIFI_STATE
and ACCESS_FINE_LOCATION
permissions.
Here's a simple example of how you can turn on hotspot using this API.
private WifiManager wifiManager;
WifiConfiguration currentConfig;
WifiManager.LocalOnlyHotspotReservation hotspotReservation;
The method to turn on hotspot:
@RequiresApi(api = Build.VERSION_CODES.O)
public void turnOnHotspot() {
wifiManager.startLocalOnlyHotspot(new WifiManager.LocalOnlyHotspotCallback() {
@Override
public void onStarted(WifiManager.LocalOnlyHotspotReservation reservation) {
super.onStarted(reservation);
hotspotReservation = reservation;
currentConfig = hotspotReservation.getWifiConfiguration();
Log.v("DANG", "THE PASSWORD IS: "
+ currentConfig.preSharedKey
+ " \n SSID is : "
+ currentConfig.SSID);
hotspotDetailsDialog();
}
@Override
public void onStopped() {
super.onStopped();
Log.v("DANG", "Local Hotspot Stopped");
}
@Override
public void onFailed(int reason) {
super.onFailed(reason);
Log.v("DANG", "Local Hotspot failed to start");
}
}, new Handler());
}
`
Here's how you can get details of the locally created hotspot
private void hotspotDetaisDialog()
{
Log.v(TAG, context.getString(R.string.hotspot_details_message) + "\n" + context.getString(
R.string.hotspot_ssid_label) + " " + currentConfig.SSID + "\n" + context.getString(
R.string.hotspot_pass_label) + " " + currentConfig.preSharedKey);
}
If it throws, a security exception even after giving the required permissions then you should try enabling your location using GPS. Here's the solution.
Recently, I've developed a demo app called Spotserve. That turns on wifi hotspot for all devices with API>=15 and hosts a demo server on that hotspot. You can check that for more details. Hope this helps!
Get current working directory in a Qt application
Thank you RedX and Kaz for your answers. I don't get why by me it gives the path of the exe. I found an other way to do it :
QString pwd("");
char * PWD;
PWD = getenv ("PWD");
pwd.append(PWD);
cout << "Working directory : " << pwd << flush;
It is less elegant than a single line... but it works for me.
Remove a specific character using awk or sed
tr
can be more concise for removing characters than sed
or awk
, especially when you want to remove different characters from a string.
Removing double quotes:
echo '"Hi"' | tr -d \"
# Produces Hi without quotes
Removing different kinds of brackets:
echo '[{Hi}]' | tr -d {}[]
# Produces Hi without brackets
-d
stands for "delete".
Hibernate JPA Sequence (non-Id)
If you are using postgresql
And i'm using in spring boot 1.5.6
@Column(columnDefinition = "serial")
@Generated(GenerationTime.INSERT)
private Integer orderID;
Difference between web server, web container and application server
The main difference between the web containers and application server is that most web containers such as Apache Tomcat implements only basic JSR like Servlet, JSP, JSTL wheres Application servers implements the entire Java EE Specification.
Every application server contains web container.
RSA Public Key format
Reference Decoder of CRL,CRT,CSR,NEW CSR,PRIVATE KEY, PUBLIC KEY,RSA,RSA Public Key Parser
RSA Public Key
-----BEGIN RSA PUBLIC KEY-----
-----END RSA PUBLIC KEY-----
Encrypted Private Key
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
-----END RSA PRIVATE KEY-----
CRL
-----BEGIN X509 CRL-----
-----END X509 CRL-----
CRT
-----BEGIN CERTIFICATE-----
-----END CERTIFICATE-----
CSR
-----BEGIN CERTIFICATE REQUEST-----
-----END CERTIFICATE REQUEST-----
NEW CSR
-----BEGIN NEW CERTIFICATE REQUEST-----
-----END NEW CERTIFICATE REQUEST-----
PEM
-----BEGIN RSA PRIVATE KEY-----
-----END RSA PRIVATE KEY-----
PKCS7
-----BEGIN PKCS7-----
-----END PKCS7-----
PRIVATE KEY
-----BEGIN PRIVATE KEY-----
-----END PRIVATE KEY-----
DSA KEY
-----BEGIN DSA PRIVATE KEY-----
-----END DSA PRIVATE KEY-----
Elliptic Curve
-----BEGIN EC PRIVATE KEY-----
-----END EC PRIVATE KEY-----
PGP Private Key
-----BEGIN PGP PRIVATE KEY BLOCK-----
-----END PGP PRIVATE KEY BLOCK-----
PGP Public Key
-----BEGIN PGP PUBLIC KEY BLOCK-----
-----END PGP PUBLIC KEY BLOCK-----
Cannot edit in read-only editor VS Code
As the @Jordan Stefanelli answer: If you encounter the same problem as me that the integrated Terminal cannot read input from user as below hanging (env. Windows 10)
my solution was to replace cygwin's gdb and g ++ with mingw64's.
then the input output are normal
also you can enable "external console" option to solve it:)
you can change it by enabling "externalConsole":true in the launch.json then you will get a pop up console window that you can type in.
Difference between 3NF and BCNF in simple terms (must be able to explain to an 8-year old)
Your pizza can have exactly three topping types:
- one type of cheese
- one type of meat
- one type of vegetable
So we order two pizzas and choose the following toppings:
Pizza Topping Topping Type
-------- ---------- -------------
1 mozzarella cheese
1 pepperoni meat
1 olives vegetable
2 mozzarella meat
2 sausage cheese
2 peppers vegetable
Wait a second, mozzarella can't be both a cheese and a meat! And sausage isn't a cheese!
We need to prevent these sorts of mistakes, to make mozzarella always be cheese. We should use a separate table for this, so we write down that fact in only one place.
Pizza Topping
-------- ----------
1 mozzarella
1 pepperoni
1 olives
2 mozzarella
2 sausage
2 peppers
Topping Topping Type
---------- -------------
mozzarella cheese
pepperoni meat
olives vegetable
sausage meat
peppers vegetable
That was the explanation that an 8 year-old might understand. Here is the more technical version.
BCNF acts differently from 3NF only when there are multiple overlapping candidate keys.
The reason is that the functional dependency X -> Y
is of course true if Y
is a subset of X
. So in any table that has only one candidate key and is in 3NF, it is already in BCNF because there is no column (either key or non-key) that is functionally dependent on anything besides that key.
Because each pizza must have exactly one of each topping type, we know that (Pizza, Topping Type) is a candidate key. We also know intuitively that a given topping cannot belong to different types simultaneously. So (Pizza, Topping) must be unique and therefore is also a candidate key. So we have two overlapping candidate keys.
I showed an anomaly where we marked mozarella as the wrong topping type. We know this is wrong, but the rule that makes it wrong is a dependency Topping -> Topping Type
which is not a valid dependency for BCNF for this table. It's a dependency on something other than a whole candidate key.
So to solve this, we take Topping Type out of the Pizzas table and make it a non-key attribute in a Toppings table.
iFrame src change event detection?
You may want to use the onLoad
event, as in the following example:
<iframe src="http://www.google.com/" onLoad="alert('Test');"></iframe>
The alert will pop-up whenever the location within the iframe changes. It works in all modern browsers, but may not work in some very older browsers like IE5 and early Opera. (Source)
If the iframe is showing a page within the same domain of the parent, you would be able to access the location with contentWindow.location
, as in the following example:
<iframe src="/test.html" onLoad="alert(this.contentWindow.location);"></iframe>
How do I implement onchange of <input type="text"> with jQuery?
You can do this in different ways, keyup is one of them. But i am giving example below with on change.
$('input[name="vat_id"]').on('change', function() {
if($(this).val().length == 0) {
alert('Input field is empty');
}
});
NB: input[name="vat_id"] replace with your input ID or name.
What is the purpose of .PHONY in a Makefile?
The special target .PHONY:
allows to declare phony targets, so that make
will not check them as actual file names: it will work all the time even if such files still exist.
You can put several .PHONY:
in your Makefile
:
.PHONY: all
all : prog1 prog2
...
.PHONY: clean distclean
clean :
...
distclean :
...
There is another way to declare phony targets : simply put ::
without prerequisites :
all :: prog1 prog2
...
clean ::
...
distclean ::
...
The ::
has other special meanings, see here, but without prerequisites it always execute the recipes, even if the target already exists, thus acting as a phony target.
Laravel Eloquent get results grouped by days
I believe I have found a solution to this, the key is the DATE() function in mysql, which converts a DateTime into just Date:
DB::table('page_views')
->select(DB::raw('DATE(created_at) as date'), DB::raw('count(*) as views'))
->groupBy('date')
->get();
However, this is not really an Laravel Eloquent solution, since this is a raw query.The following is what I came up with in Eloquent-ish syntax. The first where clause uses carbon dates to compare.
$visitorTraffic = PageView::where('created_at', '>=', \Carbon\Carbon::now->subMonth())
->groupBy('date')
->orderBy('date', 'DESC')
->get(array(
DB::raw('Date(created_at) as date'),
DB::raw('COUNT(*) as "views"')
));
Import Excel to Datagridview
I used the following code, it's working!
using System.Data.OleDb;
using System.IO;
using System.Text.RegularExpressions;
private void btopen_Click(object sender, EventArgs e)
{
try
{
OpenFileDialog openFileDialog1 = new OpenFileDialog(); //create openfileDialog Object
openFileDialog1.Filter = "XML Files (*.xml; *.xls; *.xlsx; *.xlsm; *.xlsb) |*.xml; *.xls; *.xlsx; *.xlsm; *.xlsb";//open file format define Excel Files(.xls)|*.xls| Excel Files(.xlsx)|*.xlsx|
openFileDialog1.FilterIndex = 3;
openFileDialog1.Multiselect = false; //not allow multiline selection at the file selection level
openFileDialog1.Title = "Open Text File-R13"; //define the name of openfileDialog
openFileDialog1.InitialDirectory = @"Desktop"; //define the initial directory
if (openFileDialog1.ShowDialog() == DialogResult.OK) //executing when file open
{
string pathName = openFileDialog1.FileName;
fileName = System.IO.Path.GetFileNameWithoutExtension(openFileDialog1.FileName);
DataTable tbContainer = new DataTable();
string strConn = string.Empty;
string sheetName = fileName;
FileInfo file = new FileInfo(pathName);
if (!file.Exists) { throw new Exception("Error, file doesn't exists!"); }
string extension = file.Extension;
switch (extension)
{
case ".xls":
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
break;
case ".xlsx":
strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + pathName + ";Extended Properties='Excel 12.0;HDR=Yes;IMEX=1;'";
break;
default:
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
break;
}
OleDbConnection cnnxls = new OleDbConnection(strConn);
OleDbDataAdapter oda = new OleDbDataAdapter(string.Format("select * from [{0}$]", sheetName), cnnxls);
oda.Fill(tbContainer);
dtGrid.DataSource = tbContainer;
}
}
catch (Exception)
{
MessageBox.Show("Error!");
}
}
Java Scanner class reading strings
The reason for the error is that the nextInt only pulls the integer, not the newline. If you add a in.nextLine() before your for loop, it will eat the empty new line and allow you to enter 3 names.
int nnames;
String names[];
System.out.print("How many names are you going to save: ");
Scanner in = new Scanner(System.in);
nnames = in.nextInt();
names = new String[nnames];
in.nextLine();
for (int i = 0; i < names.length; i++){
System.out.print("Type a name: ");
names[i] = in.nextLine();
}
or just read the line and parse the value as an Integer.
int nnames;
String names[];
System.out.print("How many names are you going to save: ");
Scanner in = new Scanner(System.in);
nnames = Integer.parseInt(in.nextLine().trim());
names = new String[nnames];
for (int i = 0; i < names.length; i++){
System.out.print("Type a name: ");
names[i] = in.nextLine();
}
How to hide columns in HTML table?
you can also use:
<td style="visibility:hidden;">
or
<td style="visibility:collapse;">
The difference between them that "hidden" hides the cell but it holds the space but with "collapse" the space is not held like display:none. This is significant when hidding a whole column or row.
What permission do I need to access Internet from an Android application?
forget about adding the permission into the manifest
Add this code as a method
public static boolean hasPermissions(Context context, String... permissions)
{
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null)
{
for (String permission : permissions)
{
if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED)
{
return false;
}
}
}
return true;
}
and write this in your Main
int PERMISSION_ALL = 1;
String[] PERMISSIONS = {Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_SMS, Manifest.permission.CAMERA};
if (!hasPermissions(this, PERMISSIONS)) {
ActivityCompat.requestPermissions(this, PERMISSIONS, PERMISSION_ALL);
}
Oracle date "Between" Query
As APC rightly pointed out, your start_date column appears to be a TIMESTAMP but it could be a TIMESTAMP WITH LOCAL TIMEZONE or TIMESTAMP WITH TIMEZONE datatype too. These could well influence any queries you were doing on the data if your database server was in a different timezone to yourself. However, let's keep this simple and assume you are in the same timezone as your server. First, to give you the confidence, check that the start_date is a TIMESTAMP data type.
Use the SQLPlus DESCRIBE command (or the equivalent in your IDE) to verify this column is a TIMESTAMP data type.
eg
DESCRIBE mytable
Should report :
Name Null? Type
----------- ----- ------------
NAME VARHAR2(20)
START_DATE TIMESTAMP
If it is reported as a Type = TIMESTAMP then you can query your date ranges with simplest TO_TIMESTAMP date conversion, one which requires no argument (or picture).
We use TO_TIMESTAMP to ensure that any index on the START_DATE column is considered by the optimizer. APC's answer also noted that a function based index could have been created on this column and that would influence the SQL predicate but we cannot comment on that in this query. If you want to know how to find out what indexes have been applied to table, post another question and we can answer that separately.
So, assuming there is an index on start_date, which is a TIMESTAMP datatype and you want the optimizer to consider it, your SQL would be :
select * from mytable where start_date between to_timestamp('15-JAN-10') AND to_timestamp('17-JAN-10')+.9999999
+.999999999 is very close to but isn't quite 1 so the conversion of 17-JAN-10 will be as close to midnight on that day as possible, therefore you query returns both rows.
The database will see the BETWEEN as from 15-JAN-10 00:00:00:0000000 to 17-JAN-10 23:59:59:99999 and will therefore include all dates from 15th,16th and 17th Jan 2010 whatever the time component of the timestamp.
Hope that helps.
Dazzer
How to change MenuItem icon in ActionBar programmatically
I resolved this problem this way:
In onCreateOptionsMenu
:
this.menu = menu;
this.menu.add("calendar");
ImageView imageView = new ImageView(getActivity());
imageView.setMinimumHeight(128);
imageView.setMinimumWidth(128);
imageView.setImageDrawable(yourDrawable);
MenuItem item = this.menu.getItem(0);
item.setActionView(imageView);
in onOptionsItemSelected
:
if (item.getOrder() == 0) {
//TODO
return true;
}
Using Switch Statement to Handle Button Clicks
Hi its quite simple to make switch between buttons using switch case:-
package com.example.browsebutton;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
Button b1,b2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b1=(Button)findViewById(R.id.button1);
b2=(Button)findViewById(R.id.button2);
b1.setOnClickListener(this);
b2.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
int id=v.getId();
switch(id) {
case R.id.button1:
Toast.makeText(getBaseContext(), "btn1", Toast.LENGTH_LONG).show();
//Your Operation
break;
case R.id.button2:
Toast.makeText(getBaseContext(), "btn2", Toast.LENGTH_LONG).show();
//Your Operation
break;
}
}}
www-data permissions?
As stated in an article by Slicehost:
User setup
So let's start by adding the main user to the Apache user group:
sudo usermod -a -G www-data demo
That adds the user 'demo' to the 'www-data' group. Do ensure you use
both the -a and the -G options with the usermod command shown above.
You will need to log out and log back in again to enable the group
change.
Check the groups now:
groups
...
# demo www-data
So now I am a member of two groups: My own (demo) and the Apache group
(www-data).
Folder setup
Now we need to ensure the public_html folder is owned by the main user
(demo) and is part of the Apache group (www-data).
Let's set that up:
sudo chgrp -R www-data /home/demo/public_html
As we are talking about permissions I'll add a quick note regarding
the sudo command: It's a good habit to use absolute paths
(/home/demo/public_html) as shown above rather than relative paths
(~/public_html). It ensures sudo is being used in the correct
location.
If you have a public_html folder with symlinks in place then be
careful with that command as it will follow the symlinks. In those
cases of a working public_html folder, change each folder by hand.
Setgid
Good so far, but remember the command we just gave only affects
existing folders. What about anything new?
We can set the ownership so anything new is also in the 'www-data'
group.
The first command will change the permissions for the public_html
directory to include the "setgid" bit:
sudo chmod 2750 /home/demo/public_html
That will ensure that any new files are given the group 'www-data'. If
you have subdirectories, you'll want to run that command for each
subdirectory (this type of permission doesn't work with '-R').
Fortunately new subdirectories will be created with the 'setgid' bit
set automatically.
If we need to allow write access to Apache, to an uploads directory
for example, then set the permissions for that directory like so:
sudo chmod 2770 /home/demo/public_html/domain1.com/public/uploads
The permissions only need to be set once as new files will
automatically be assigned the correct ownership.
How can I check the system version of Android?
Given you have bash
on your android device, you can use this bash function :
function androidCodeName {
androidRelease=$(getprop ro.build.version.release)
androidCodeName=$(getprop ro.build.version.codename)
# Time "androidRelease" x10 to test it as an integer
case $androidRelease in
[0-9].[0-9]|[0-9].[0-9].|[0-9].[0-9].[0-9]) androidRelease=$(echo $androidRelease | cut -d. -f1-2 | tr -d .);;
[0-9].) androidRelease=$(echo $androidRelease | sed 's/\./0/');;
[0-9]) androidRelease+="0";;
esac
[ -n "$androidRelease" ] && [ $androidCodeName = REL ] && {
# Do not use "androidCodeName" when it equals to "REL" but infer it from "androidRelease"
androidCodeName=""
case $androidRelease in
10) androidCodeName+=NoCodename;;
11) androidCodeName+="Petit Four";;
15) androidCodeName+=Cupcake;;
20|21) androidCodeName+=Eclair;;
22) androidCodeName+=FroYo;;
23) androidCodeName+=Gingerbread;;
30|31|32) androidCodeName+=Honeycomb;;
40) androidCodeName+="Ice Cream Sandwich";;
41|42|43) androidCodeName+="Jelly Bean";;
44) androidCodeName+=KitKat;;
50|51) androidCodeName+=Lollipop;;
60) androidCodeName+=Marshmallow;;
70|71) androidCodeName+=Nougat;;
80|81) androidCodeName+=Oreo;;
90) androidCodeName+=Pie;;
100) androidCodeName+=ToBeReleased;;
*) androidCodeName=unknown;;
esac
}
echo $androidCodeName
}
Understanding the Rails Authenticity Token
Minimal attack example that would be prevented: CSRF
On my website evil.com
I convince you to submit the following form:
<form action="http://bank.com/transfer" method="post">
<p><input type="hidden" name="to" value="ciro"></p>
<p><input type="hidden" name="ammount" value="100"></p>
<p><button type="submit">CLICK TO GET PRIZE!!!</button></p>
</form>
If you are logged into your bank through session cookies, then the cookies would be sent and the transfer would be made without you even knowing it.
That is were the CSRF token comes into play:
- with the GET response that that returned the form, Rails sends a very long random hidden parameter
- when the browser makes the POST request, it will send the parameter along, and the server will only accept it if it matches
So the form on an authentic browser would look like:
<form action="http://bank.com/transfer" method="post">
<p><input type="hidden" name="authenticity_token" value="j/DcoJ2VZvr7vdf8CHKsvjdlDbmiizaOb5B8DMALg6s=" ></p>
<p><input type="hidden" name="to" value="ciro"></p>
<p><input type="hidden" name="ammount" value="100"></p>
<p><button type="submit">Send 100$ to Ciro.</button></p>
</form>
Thus, my attack would fail, since it was not sending the authenticity_token
parameter, and there is no way I could have guessed it since it is a huge random number.
This prevention technique is called Synchronizer Token Pattern.
Same Origin Policy
But what if the attacker made two requests with JavaScript, one to read the token, and the second one to make the transfer?
The synchronizer token pattern alone is not enough to prevent that!
This is where the Same Origin Policy comes to the rescue, as I have explained at: https://security.stackexchange.com/questions/8264/why-is-the-same-origin-policy-so-important/72569#72569
How Rails sends the tokens
Covered at: Rails: How Does csrf_meta_tag Work?
Basically:
HTML helpers like form_tag
add a hidden field to the form for you if it's not a GET form
AJAX is dealt with automatically by jquery-ujs, which reads the token from the meta
elements added to your header by csrf_meta_tags
(present in the default template), and adds it to any request made.
uJS also tries to update the token in forms in outdated cached fragments.
Other prevention approaches
what is the differences between sql server authentication and windows authentication..?
Mssql Authentication is highly preferable where possible. It allows you to conform with an existing windows domain already used at your workplace, and you don't have to know your user's passwords.
However, It seems that it would not be possible for use in the occasion that the server's machine does not authenticate to your local workplace's intranet.
If you use sql authentication, security will be entirely up to you.
If you use microsoft authentication, security is essentially taken care of for you, but you'll be dealing with additional restrictions.
css3 text-shadow in IE9
I was looking for a cross-browser text-stroke solution that works when overlaid on background images. think I have a solution for this that doesn't involve extra mark-up, js and works in IE7-9 (I haven't tested 6), and doesn't cause aliasing problems.
This is a combination of using CSS3 text-shadow, which has good support except IE (http://caniuse.com/#search=text-shadow), then using a combination of filters for IE. CSS3 text-stroke support is poor at the moment.
IE Filters
The glow filter (http://www.impressivewebs.com/css3-text-shadow-ie/) looks terrible, so I didn't use that.
David Hewitt's answer involved adding dropshadow filters in a combination of directions. ClearType is then removed unfortunately so we end up with badly aliased text.
I then combined some of the elements suggested on useragentman with the dropshadow filters.
Putting it together
This example would be black text with a white stroke. I'm using conditional html classes by the way to target IE (http://paulirish.com/2008/conditional-stylesheets-vs-css-hacks-answer-neither/).
#myelement {
color: #000000;
text-shadow:
-1px -1px 0 #ffffff,
1px -1px 0 #ffffff,
-1px 1px 0 #ffffff,
1px 1px 0 #ffffff;
}
html.ie7 #myelement,
html.ie8 #myelement,
html.ie9 #myelement {
background-color: white;
filter: progid:DXImageTransform.Microsoft.Chroma(color='white') progid:DXImageTransform.Microsoft.Alpha(opacity=100) progid:DXImageTransform.Microsoft.dropshadow(color=#ffffff,offX=1,offY=1) progid:DXImageTransform.Microsoft.dropshadow(color=#ffffff,offX=-1,offY=1) progid:DXImageTransform.Microsoft.dropshadow(color=#ffffff,offX=1,offY=-1) progid:DXImageTransform.Microsoft.dropshadow(color=#ffffff,offX=-1,offY=-1);
zoom: 1;
}
How to download a file over HTTP?
You can get the progress feedback with urlretrieve as well:
def report(blocknr, blocksize, size):
current = blocknr*blocksize
sys.stdout.write("\r{0:.2f}%".format(100.0*current/size))
def downloadFile(url):
print "\n",url
fname = url.split('/')[-1]
print fname
urllib.urlretrieve(url, fname, report)
Calling C/C++ from Python?
I love cppyy, it makes it very easy to extend Python with C++ code, dramatically increasing performance when needed.
It is powerful and frankly very simple to use,
here it is an example of how you can create a numpy array and pass it to a class member function in C++.
cppyy_test.py
import cppyy
import numpy as np
cppyy.include('Buffer.h')
s = cppyy.gbl.Buffer()
numpy_array = np.empty(32000, np.float64)
s.get_numpy_array(numpy_array.data, numpy_array.size)
print(numpy_array[:20])
Buffer.h
struct Buffer {
void get_numpy_array(double *ad, int size) {
for( long i=0; i < size; i++)
ad[i]=i;
}
};
You can also create a Python module very easily (with CMake), this way you will avoid recompile the C++ code all the times.
Best way to center a <div> on a page vertically and horizontally?
Here is a script i wrote a while back (it is written using the jQuery library):
var centerIt = function (el /* (jQuery element) Element to center */) {
if (!el) {
return;
}
var moveIt = function () {
var winWidth = $(window).width();
var winHeight = $(window).height();
el.css("position","absolute").css("left", ((winWidth / 2) - (el.width() / 2)) + "px").css("top", ((winHeight / 2) - (el.height() / 2)) + "px");
};
$(window).resize(moveIt);
moveIt();
};
Entity Framework Migrations renaming tables and columns
If you don't like writing/changing the required code in the Migration class manually, you can follow a two-step approach which automatically make the RenameColumn
code which is required:
Step One Use the ColumnAttribute
to introduce the new column name and then add-migration (e.g. Add-Migration ColumnChanged
)
public class ReportPages
{
[Column("Section_Id")] //Section_Id
public int Group_Id{get;set}
}
Step-Two change the property name and again apply to same migration (e.g. Add-Migration ColumnChanged -force
) in the Package Manager Console
public class ReportPages
{
[Column("Section_Id")] //Section_Id
public int Section_Id{get;set}
}
If you look at the Migration class you can see the automatically code generated is RenameColumn
.
matplotlib has no attribute 'pyplot'
Did you import it? Importing matplotlib
is not enough.
>>> import matplotlib
>>> matplotlib.pyplot
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'pyplot'
but
>>> import matplotlib.pyplot
>>> matplotlib.pyplot
works.
pyplot is a submodule of matplotlib and not immediately imported when you import matplotlib.
The most common form of importing pyplot is
import matplotlib.pyplot as plt
Thus, your statements won't be too long, e.g.
plt.plot([1,2,3,4,5])
instead of
matplotlib.pyplot.plot([1,2,3,4,5])
And: pyplot
is not a function, it's a module! So don't call it, use the functions defined inside this module instead. See my example above
Check if all checkboxes are selected
I think the easiest way is checking for this condition:
$('.abc:checked').length == $('.abc').length
You could do it every time a new checkbox is checked:
$(".abc").change(function(){
if ($('.abc:checked').length == $('.abc').length) {
//do something
}
});
How to call JavaScript function instead of href in HTML
Your should also separate the javascript from the HTML.
HTML:
<a href="#" id="function-click"><img title="next page" alt="next page" src="/themes/me/img/arrn.png"></a>
javascript:
myLink = document.getElementById('function-click');
myLink.onclick = ShowOld(2367,146986,2);
Just make sure the last line in the ShowOld function is:
return false;
as this will stop the link from opening in the browser.
Get Image Height and Width as integer values?
getimagesize('image.jpg')
function works only if allow_url_fopen
is set to 1 or On inside php.ini file on the server,
if it is not enabled, one should use
ini_set('allow_url_fopen',1);
on top of the file where getimagesize() function is used.
Get List of connected USB Devices
Adel Hazzah's answer gives working code, Daniel Widdis's and Nedko's comments mention that you need to query Win32_USBControllerDevice and use its Dependent property, and Daniel's answer gives a lot of detail without code.
Here's a synthesis of the above discussion to provide working code that lists the directly accessible PNP device properties of all connected USB devices:
using System;
using System.Collections.Generic;
using System.Management; // reference required
namespace cSharpUtilities
{
class UsbBrowser
{
public static void PrintUsbDevices()
{
IList<ManagementBaseObject> usbDevices = GetUsbDevices();
foreach (ManagementBaseObject usbDevice in usbDevices)
{
Console.WriteLine("----- DEVICE -----");
foreach (var property in usbDevice.Properties)
{
Console.WriteLine(string.Format("{0}: {1}", property.Name, property.Value));
}
Console.WriteLine("------------------");
}
}
public static IList<ManagementBaseObject> GetUsbDevices()
{
IList<string> usbDeviceAddresses = LookUpUsbDeviceAddresses();
List<ManagementBaseObject> usbDevices = new List<ManagementBaseObject>();
foreach (string usbDeviceAddress in usbDeviceAddresses)
{
// query MI for the PNP device info
// address must be escaped to be used in the query; luckily, the form we extracted previously is already escaped
ManagementObjectCollection curMoc = QueryMi("Select * from Win32_PnPEntity where PNPDeviceID = " + usbDeviceAddress);
foreach (ManagementBaseObject device in curMoc)
{
usbDevices.Add(device);
}
}
return usbDevices;
}
public static IList<string> LookUpUsbDeviceAddresses()
{
// this query gets the addressing information for connected USB devices
ManagementObjectCollection usbDeviceAddressInfo = QueryMi(@"Select * from Win32_USBControllerDevice");
List<string> usbDeviceAddresses = new List<string>();
foreach(var device in usbDeviceAddressInfo)
{
string curPnpAddress = (string)device.GetPropertyValue("Dependent");
// split out the address portion of the data; note that this includes escaped backslashes and quotes
curPnpAddress = curPnpAddress.Split(new String[] { "DeviceID=" }, 2, StringSplitOptions.None)[1];
usbDeviceAddresses.Add(curPnpAddress);
}
return usbDeviceAddresses;
}
// run a query against Windows Management Infrastructure (MI) and return the resulting collection
public static ManagementObjectCollection QueryMi(string query)
{
ManagementObjectSearcher managementObjectSearcher = new ManagementObjectSearcher(query);
ManagementObjectCollection result = managementObjectSearcher.Get();
managementObjectSearcher.Dispose();
return result;
}
}
}
You'll need to add exception handling if you want it. Consult Daniel's answer if you want to figure out the device tree and such.
How to use "Share image using" sharing Intent to share images in android?
Bitmap icon = mBitmap;
Intent share = new Intent(Intent.ACTION_SEND);
share.setType("image/jpeg");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
icon.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
File f = new File(Environment.getExternalStorageDirectory() + File.separator + "temporary_file.jpg");
try {
f.createNewFile();
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
} catch (IOException e) {
e.printStackTrace();
}
share.putExtra(Intent.EXTRA_STREAM, Uri.parse("file:///sdcard/temporary_file.jpg"));
startActivity(Intent.createChooser(share, "Share Image"));
Matplotlib scatter plot with different text at each data point
I would love to add that you can even use arrows /text boxes to annotate the labels. Here is what I mean:
import random
import matplotlib.pyplot as plt
y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]
fig, ax = plt.subplots()
ax.scatter(z, y)
ax.annotate(n[0], (z[0], y[0]), xytext=(z[0]+0.05, y[0]+0.3),
arrowprops=dict(facecolor='red', shrink=0.05))
ax.annotate(n[1], (z[1], y[1]), xytext=(z[1]-0.05, y[1]-0.3),
arrowprops = dict( arrowstyle="->",
connectionstyle="angle3,angleA=0,angleB=-90"))
ax.annotate(n[2], (z[2], y[2]), xytext=(z[2]-0.05, y[2]-0.3),
arrowprops = dict(arrowstyle="wedge,tail_width=0.5", alpha=0.1))
ax.annotate(n[3], (z[3], y[3]), xytext=(z[3]+0.05, y[3]-0.2),
arrowprops = dict(arrowstyle="fancy"))
ax.annotate(n[4], (z[4], y[4]), xytext=(z[4]-0.1, y[4]-0.2),
bbox=dict(boxstyle="round", alpha=0.1),
arrowprops = dict(arrowstyle="simple"))
plt.show()
Which will generate the following graph:
Support for "border-radius" in IE
A workaround and a handy tool:
CSS3Pie uses .htc files and the behavior property to implement CSS3 into IE 6 - 8.
Modernizr is a bit of javascript that will put classes on your html element, allowing you to serve different style definitions to different browsers based on their capabilities.
Obviously, these both add more overhead, but with IE9 due to only run on Vista/7 we might be stuck for quite awhile. As of August 2010 Windows XP still accounts for 48% of web client OSes.
How to finish current activity in Android
You need to call finish()
from the UI thread, not a background thread. The way to do this is to declare a Handler and ask the Handler to run a Runnable on the UI thread. For example:
public class LoadingScreen extends Activity{
private LoadingScreen loadingScreen;
Intent i = new Intent(this, HomeScreen.class);
Handler handler;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
handler = new Handler();
setContentView(R.layout.loading);
CountDownTimer timer = new CountDownTimer(10000, 1000) //10seceonds Timer
{
@Override
public void onTick(long l)
{
}
@Override
public void onFinish()
{
handler.post(new Runnable() {
public void run() {
loadingScreen.finishActivity(0);
startActivity(i);
}
});
};
}.start();
}
}
Biggest advantage to using ASP.Net MVC vs web forms
If you're working with other developers, such as PHP or JSP (and i'm guessing rails) - you're going to have a much easier time converting or collaborating on pages because you wont have all those 'nasty' ASP.NET events and controls everywhere.
(Built-in) way in JavaScript to check if a string is a valid number
The accepted answer for this question has quite a few flaws (as highlighted by couple of other users). This is one of the easiest & proven way to approach it in javascript:
function isNumeric(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}
Below are some good test cases:
console.log(isNumeric(12345678912345678912)); // true
console.log(isNumeric('2 ')); // true
console.log(isNumeric('-32.2 ')); // true
console.log(isNumeric(-32.2)); // true
console.log(isNumeric(undefined)); // false
// the accepted answer fails at these tests:
console.log(isNumeric('')); // false
console.log(isNumeric(null)); // false
console.log(isNumeric([])); // false
How do you create a static class in C++?
As it has been noted here, a better way of achieving this in C++ might be using namespaces. But since no one has mentioned the final
keyword here, I'm posting what a direct equivalent of static class
from C# would look like in C++11 or later:
class BitParser final
{
public:
BitParser() = delete;
static bool GetBitAt(int buffer, int pos);
};
bool BitParser::GetBitAt(int buffer, int pos)
{
// your code
}