Programs & Examples On #Urchin

UITableView Cell selected Color?

Swift 5 - Xcode version 12.1 (12A7403)

|Step One|
Add the following to your AppDelegate.swift file

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    let colorView = UIView()
    colorView.backgroundColor = UIColor.lightGray

    UITableViewCell.appearance().selectedBackgroundView = colorView
        
    return true
}

|Step Two|
Make sure your cell's Content View background is set to "Clear Color" (and not "Default") in the Attributes Inspector. This is done to not conflict with your App Delegate setting.

How can I remove a key from a Python dictionary?

del my_dict[key] is slightly faster than my_dict.pop(key) for removing a key from a dictionary when the key exists

>>> import timeit
>>> setup = "d = {i: i for i in range(100000)}"

>>> timeit.timeit("del d[3]", setup=setup, number=1)
1.79e-06
>>> timeit.timeit("d.pop(3)", setup=setup, number=1)
2.09e-06
>>> timeit.timeit("d2 = {key: val for key, val in d.items() if key != 3}", setup=setup, number=1)
0.00786

But when the key doesn't exist if key in my_dict: del my_dict[key] is slightly faster than my_dict.pop(key, None). Both are at least three times faster than del in a try/except statement:

>>> timeit.timeit("if 'missing key' in d: del d['missing key']", setup=setup)
0.0229
>>> timeit.timeit("d.pop('missing key', None)", setup=setup)
0.0426
>>> try_except = """
... try:
...     del d['missing key']
... except KeyError:
...     pass
... """
>>> timeit.timeit(try_except, setup=setup)
0.133

How to compare 2 files fast using .NET?

Edit: This method would not work for comparing binary files!

In .NET 4.0, the File class has the following two new methods:

public static IEnumerable<string> ReadLines(string path)
public static IEnumerable<string> ReadLines(string path, Encoding encoding)

Which means you could use:

bool same = File.ReadLines(path1).SequenceEqual(File.ReadLines(path2));

Understanding __get__ and __set__ and Python descriptors

You'd see https://docs.python.org/3/howto/descriptor.html#properties

class Property(object):
    "Emulate PyProperty_Type() in Objects/descrobject.c"

    def __init__(self, fget=None, fset=None, fdel=None, doc=None):
        self.fget = fget
        self.fset = fset
        self.fdel = fdel
        if doc is None and fget is not None:
            doc = fget.__doc__
        self.__doc__ = doc

    def __get__(self, obj, objtype=None):
        if obj is None:
            return self
        if self.fget is None:
            raise AttributeError("unreadable attribute")
        return self.fget(obj)

    def __set__(self, obj, value):
        if self.fset is None:
            raise AttributeError("can't set attribute")
        self.fset(obj, value)

    def __delete__(self, obj):
        if self.fdel is None:
            raise AttributeError("can't delete attribute")
        self.fdel(obj)

    def getter(self, fget):
        return type(self)(fget, self.fset, self.fdel, self.__doc__)

    def setter(self, fset):
        return type(self)(self.fget, fset, self.fdel, self.__doc__)

    def deleter(self, fdel):
        return type(self)(self.fget, self.fset, fdel, self.__doc__)

this.getClass().getClassLoader().getResource("...") and NullPointerException

When eclipse runs the test case it will look for the file in target/classes not src/test/resources. When the resource is saved eclipse should copy it from src/test/resources to target/classes if it has changed but if for some reason this has not happened then you will get this error. Check that the file exists in target/classes to see if this is the problem.

R object identification

str(x)

It's all you need to remember for 99% of cases.

Recursive directory listing in DOS

I like to use the following to get a nicely sorted listing of the current dir:

> dir . /s /b sortorder:N

How to debug in Django, the good way?

One of your best option to debug Django code is via wdb: https://github.com/Kozea/wdb

wdb works with python 2 (2.6, 2.7), python 3 (3.2, 3.3, 3.4, 3.5) and pypy. Even better, it is possible to debug a python 2 program with a wdb server running on python 3 and vice-versa or debug a program running on a computer with a debugging server running on another computer inside a web page on a third computer! Even betterer, it is now possible to pause a currently running python process/thread using code injection from the web interface. (This requires gdb and ptrace enabled) In other words it's a very enhanced version of pdb directly in your browser with nice features.

Install and run the server, and in your code add:

import wdb
wdb.set_trace()

According to the author, main differences with respect to pdb are:

For those who don’t know the project, wdb is a python debugger like pdb, but with a slick web front-end and a lot of additional features, such as:

  • Source syntax highlighting
  • Visual breakpoints
  • Interactive code completion using jedi
  • Persistent breakpoints
  • Deep objects inspection using mouse Multithreading / Multiprocessing support
  • Remote debugging
  • Watch expressions
  • In debugger code edition
  • Popular web servers integration to break on error
  • In exception breaking during trace (not post-mortem) in contrary to the werkzeug debugger for instance
  • Breaking in currently running programs through code injection (on supported systems)

It has a great browser-based user interface. A joy to use! :)

datetime dtypes in pandas read_csv

There is a parse_dates parameter for read_csv which allows you to define the names of the columns you want treated as dates or datetimes:

date_cols = ['col1', 'col2']
pd.read_csv(file, sep='\t', header=None, names=headers, parse_dates=date_cols)

Jquery/Ajax call with timer

If you want to set something on a timer, you can use JavaScript's setTimeout or setInterval methods:

setTimeout ( expression, timeout );
setInterval ( expression, interval );

Where expression is a function and timeout and interval are integers in milliseconds. setTimeout runs the timer once and runs the expression once whereas setInterval will run the expression every time the interval passes.

So in your case it would work something like this:

setInterval(function() {
    //call $.ajax here
}, 5000); //5 seconds

As far as the Ajax goes, see jQuery's ajax() method. If you run an interval, there is nothing stopping you from calling the same ajax() from other places in your code.


If what you want is for an interval to run every 30 seconds until a user initiates a form submission...and then create a new interval after that, that is also possible:

setInterval() returns an integer which is the ID of the interval.

var id = setInterval(function() {
    //call $.ajax here
}, 30000); // 30 seconds

If you store that ID in a variable, you can then call clearInterval(id) which will stop the progression.

Then you can reinstantiate the setInterval() call after you've completed your ajax form submission.

How to mount the android img file under linux?

See the answer at: http://omappedia.org/wiki/Android_eMMC_Booting#Modifying_.IMG_Files

First you need to "uncompress" userdata.img with simg2img, then you can mount it via the loop device.

The project was not built since its build path is incomplete

Here is what made the error disappear for me:

Close eclipse, open up a terminal window and run:

$ mvn clean eclipse:clean eclipse:eclipse

Are you using Maven? If so,

  1. Right-click on the project, Build Path and go to Configure Build Path
  2. Click the libraries tab. If Maven dependencies are not in the list, you need to add it.
  3. Close the dialog.

To add it: Right-click on the project, Maven → Disable Maven Nature Right-click on the project, Configure → Convert to Maven Project.

And then clean

Edit 1:

If that doesn't resolve the issue try right-clicking on your project and select properties. Select Java Build Path → Library tab. Look for a JVM. If it's not there, click to add Library and add the default JVM. If VM is there, click edit and select the default JVM. Hopefully, that works.

Edit 2:

You can also try going into the folder where you have all your projects and delete the .metadata for eclipse (be aware that you'll have to re-import all the projects afterwards! Also all the environment settings you've set would also have to be redone). After it was deleted just import the project again, and hopefully, it works.

How to send a “multipart/form-data” POST in Android with Volley

Here is Simple Solution And Complete Example for Uploading File Using Volley Android

1) Gradle Import

compile 'dev.dworks.libs:volleyplus:+'

2)Now Create a Class RequestManager

public class RequestManager {
    private static RequestManager mRequestManager;
    /**
     * Queue which Manages the Network Requests :-)
     */
    private static RequestQueue mRequestQueue;
    // ImageLoader Instance

    private RequestManager() {

    }

    public static RequestManager get(Context context) {

        if (mRequestManager == null)
            mRequestManager = new RequestManager();

        return mRequestManager;
    }

    /**
     * @param context application context
     */
    public static RequestQueue getnstance(Context context) {

        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(context);
        }

        return mRequestQueue;

    }


}

3)Now Create a Class to handle Request for uploading File WebService

public class WebService {
    private RequestQueue mRequestQueue;
    private static WebService apiRequests = null;

    public static WebService getInstance() {
        if (apiRequests == null) {
            apiRequests = new WebService();
            return apiRequests;
        }
        return apiRequests;
    }
    public void updateProfile(Context context, String doc_name, String doc_type, String appliance_id, File file, Response.Listener<String> listener, Response.ErrorListener errorListener) {
        SimpleMultiPartRequest request = new SimpleMultiPartRequest(Request.Method.POST, "YOUR URL HERE", listener, errorListener);
//        request.setParams(data);
        mRequestQueue = RequestManager.getnstance(context);
        request.addMultipartParam("token", "text", "tdfysghfhsdfh");
        request.addMultipartParam("parameter_1", "text", doc_name);
        request.addMultipartParam("dparameter_2", "text", doc_type);
        request.addMultipartParam("parameter_3", "text", appliance_id);
            request.addFile("document_file", file.getPath());

        request.setFixedStreamingMode(true);
        mRequestQueue.add(request);
    }
}

4) And Now Call The method Like This to Hit the service

public class Main2Activity extends AppCompatActivity implements Response.ErrorListener, Response.Listener<String>{

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        Button button=(Button)findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                uploadData();
            }
        });
    }

    private void uploadData() {
        WebService.getInstance().updateProfile(getActivity(), "appl_doc", "appliance", "1", mChoosenFile, this, this);
    }

    @Override
    public void onErrorResponse(VolleyError error) {

    }

    @Override
    public void onResponse(String response) {
     //Your response here 
    }
}

Python string.join(list) on object array rather than string array

You could use a list comprehension or a generator expression instead:

', '.join([str(x) for x in list])  # list comprehension
', '.join(str(x) for x in list)    # generator expression

How to reset postgres' primary key sequence when it falls out of sync?

I spent an hour trying to get djsnowsill's answer to work with a database using Mixed Case tables and columns, then finally stumbled upon the solution thanks to a comment from Manuel Darveau, but I thought I could make it a bit clearer for everyone:

CREATE OR REPLACE FUNCTION "reset_sequence" (tablename text, columnname text)
RETURNS "pg_catalog"."void" AS
$body$
DECLARE
BEGIN
EXECUTE format('SELECT setval(pg_get_serial_sequence(''%1$I'', %2$L),
        (SELECT COALESCE(MAX(%2$I)+1,1) FROM %1$I), false)',tablename,columnname);
END;
$body$  LANGUAGE 'plpgsql';

SELECT format('%s_%s_seq',table_name,column_name), reset_sequence(table_name,column_name) 
FROM information_schema.columns WHERE column_default like 'nextval%';

This has the benefit of:

  • not assuming ID column is spelled a particular way.
  • not assuming all tables have a sequence.
  • working for Mixed Case table/column names.
  • using format to be more concise.

To explain, the problem was that pg_get_serial_sequence takes strings to work out what you're referring to, so if you do:

"TableName" --it thinks it's a table or column
'TableName' --it thinks it's a string, but makes it lower case
'"TableName"' --it works!

This is achieved using ''%1$I'' in the format string, '' makes an apostrophe 1$ means first arg, and I means in quotes

CSS get height of screen resolution

You can get the window height quite easily in pure CSS, using the units "vh", each corresponding to 1% of the window height. On the example below, let's begin to centralize block.foo by adding a margin-top half the size of the screen.

.foo{
    margin-top: 50vh;
}

But that only works for 'window' size. With a dab of javascript, you could make it more versatile.

$(':root').css("--windowHeight", $( window ).height() );

That code will create a CSS variable named "--windowHeight" that carries the height of the window. To use it, just add the rule:

.foo{
    margin-top: calc( var(--windowHeight) / 2 );
}

And why is it more versatile than simply using "vh" units? Because you can get the height of any element. Now if you want to centralize a block.foo in any container.bar, you could:

$(':root').css("--containerHeight", $( .bar ).height() );
$(':root').css("--blockHeight", $( .foo ).height() );

.foo{
    margin-top: calc( var(--containerHeight) / 2 - var(--blockHeight) / 2);
}

And finally, for it to respond to changes on the window size, you could use (in this example, the container is 50% the window height):

$( window ).resize(function() {
    $(':root').css("--containerHeight", $( .bar ).height()*0.5 );
});

get the value of input type file , and alert if empty

<script type="text/javascript">
$(document).ready(function() {
    $('#upload').bind("click",function() 
    { 
        var imgVal = $('#uploadImage').val(); 
        if(imgVal=='') 
        { 
            alert("empty input file"); 

        } 
        return false; 

    }); 
});
</script> 

<input type="file" name="image" id="uploadImage" size="30" /> 
<input type="submit" name="upload" id="upload"  class="send_upload" value="upload" /> 

Eclipse projects not showing up after placing project files in workspace/projects

Or you could try:

  1. Go to File -> Switch Workspace
  2. Select your workspace (if shown)

How to convert a Title to a URL slug in jQuery?

Combining a variety of elements from the answers here with normalize provides good coverage. Keep the order of operations to incrementally clean the url.

function clean_url(s) {
    return s.toString().normalize('NFD').replace(/[\u0300-\u036f]/g, "") //remove diacritics
            .toLowerCase()
            .replace(/\s+/g, '-') //spaces to dashes
            .replace(/&/g, '-and-') //ampersand to and
            .replace(/[^\w\-]+/g, '') //remove non-words
            .replace(/\-\-+/g, '-') //collapse multiple dashes
            .replace(/^-+/, '') //trim starting dash
            .replace(/-+$/, ''); //trim ending dash
}

normlize('NFD') breaks accented characters into their components, which are basic letters plus diacritics (the accent part). replace(/[\u0300-\u036f]/g, "") purges all the diacritics, leaving the basic letters by themselves. The rest is explained with inline comments.

How do I find out if first character of a string is a number?

Character.isDigit(string.charAt(0))

Note that this will allow any Unicode digit, not just 0-9. You might prefer:

char c = string.charAt(0);
isDigit = (c >= '0' && c <= '9');

Or the slower regex solutions:

s.substring(0, 1).matches("\\d")
// or the equivalent
s.substring(0, 1).matches("[0-9]")

However, with any of these methods, you must first be sure that the string isn't empty. If it is, charAt(0) and substring(0, 1) will throw a StringIndexOutOfBoundsException. startsWith does not have this problem.

To make the entire condition one line and avoid length checks, you can alter the regexes to the following:

s.matches("\\d.*")
// or the equivalent
s.matches("[0-9].*")

If the condition does not appear in a tight loop in your program, the small performance hit for using regular expressions is not likely to be noticeable.

Registering for Push Notifications in Xcode 8/Swift 3.0?

Heads up, you should be using the main thread for this action.

let center = UNUserNotificationCenter.current()
center.requestAuthorization(options:[.badge, .alert, .sound]) { (granted, error) in
        if granted {
            DispatchQueue.main.async(execute: {
                UIApplication.shared.registerForRemoteNotifications()
            })
        }
    }

Extracting jar to specified directory

This worked for me.

I created a folder then changed into the folder using CD option from command prompt.

Then executed the jar from there.

d:\LS\afterchange>jar xvf ..\mywar.war

How to extract the decision rules from scikit-learn decision-tree?

Codes below is my approach under anaconda python 2.7 plus a package name "pydot-ng" to making a PDF file with decision rules. I hope it is helpful.

from sklearn import tree

clf = tree.DecisionTreeClassifier(max_leaf_nodes=n)
clf_ = clf.fit(X, data_y)

feature_names = X.columns
class_name = clf_.classes_.astype(int).astype(str)

def output_pdf(clf_, name):
    from sklearn import tree
    from sklearn.externals.six import StringIO
    import pydot_ng as pydot
    dot_data = StringIO()
    tree.export_graphviz(clf_, out_file=dot_data,
                         feature_names=feature_names,
                         class_names=class_name,
                         filled=True, rounded=True,
                         special_characters=True,
                          node_ids=1,)
    graph = pydot.graph_from_dot_data(dot_data.getvalue())
    graph.write_pdf("%s.pdf"%name)

output_pdf(clf_, name='filename%s'%n)

a tree graphy show here

Replacing Numpy elements if condition is met

I am not sure I understood your question, but if you write:

mask_data[:3, :3] = 1
mask_data[3:, 3:] = 0

This will make all values of mask data whose x and y indexes are less than 3 to be equal to 1 and all rest to be equal to 0

How do I access named capturing groups in a .NET Regex?

Additionally if someone have a use case where he needs group names before executing search on Regex object he can use:

var regex = new Regex(pattern); // initialized somewhere
// ...
var groupNames = regex.GetGroupNames();

How to convert an array to object in PHP?

Actually if you want to use this with multi-dimensional arrays you would want to use some recursion.

static public function array_to_object(array $array)
{
    foreach($array as $key => $value)
    {
        if(is_array($value))
        {
            $array[$key] = self::array_to_object($value);
        }
    }
    return (object)$array;
}

How do I create a chart with multiple series using different X values for each series?

You need to use the Scatter chart type instead of Line. That will allow you to define separate X values for each series.

rotate image with css

I know this topic is old, but there are no correct answers.

rotation transform rotates the element from its center, so, a wider element will rotate this way:

enter image description here

Applying overflow: hidden hides the longest dimension as you can see here:

enter image description here

_x000D_
_x000D_
img{_x000D_
  border: 1px solid #000;_x000D_
  transform:          rotate(270deg);_x000D_
  -ms-transform:      rotate(270deg);_x000D_
  -moz-transform:     rotate(270deg);_x000D_
  -webkit-transform:  rotate(270deg);_x000D_
  -o-transform:       rotate(270deg);_x000D_
}_x000D_
.imagetest{_x000D_
  overflow: hidden_x000D_
}
_x000D_
<article>_x000D_
<section class="photo">_x000D_
<div></div>_x000D_
<div class="imagetest">_x000D_
<img src="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSqVNRUwpfOwZ5n4kvVXea2VHd6QZGACVVaBOl5aJ2EGSG-WAIF" width=100%/>_x000D_
</div>_x000D_
</section>_x000D_
</article>
_x000D_
_x000D_
_x000D_

So, what I do is some calculations, in my example the picture is 455px width and 111px height and we have to add some margins based on these dimensions:

  • left margin: (width - height)/2
  • top margin: (height - width)/2

in CSS:

margin: calc((455px - 111px)/2) calc((111px - 455px)/2);

Result:

enter image description here

_x000D_
_x000D_
img{_x000D_
  border: 1px solid #000;_x000D_
  transform:          rotate(270deg);_x000D_
  -ms-transform:      rotate(270deg);_x000D_
  -moz-transform:     rotate(270deg);_x000D_
  -webkit-transform:  rotate(270deg);_x000D_
  -o-transform:       rotate(270deg);_x000D_
  /* 455 * 111 */_x000D_
  margin: calc((455px - 111px)/2) calc((111px - 455px)/2);_x000D_
}
_x000D_
<article>_x000D_
<section class="photo">_x000D_
<div></div>_x000D_
<div class="imagetest">_x000D_
<img src="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSqVNRUwpfOwZ5n4kvVXea2VHd6QZGACVVaBOl5aJ2EGSG-WAIF" />_x000D_
</div>_x000D_
</section>_x000D_
</article>
_x000D_
_x000D_
_x000D_

I hope it helps someone!

DLL References in Visual C++

You need to do a couple of things to use the library:

  1. Make sure that you have both the *.lib and the *.dll from the library you want to use. If you don't have the *.lib, skip #2

  2. Put a reference to the *.lib in the project. Right click the project name in the Solution Explorer and then select Configuration Properties->Linker->Input and put the name of the lib in the Additional Dependencies property.

  3. You have to make sure that VS can find the lib you just added so you have to go to the Tools menu and select Options... Then under Projects and Solutions select VC++ Directories,edit Library Directory option. From within here you can set the directory that contains your new lib by selecting the 'Library Files' in the 'Show Directories For:' drop down box. Just add the path to your lib file in the list of directories. If you dont have a lib you can omit this, but while your here you will also need to set the directory which contains your header files as well under the 'Include Files'. Do it the same way you added the lib.

After doing this you should be good to go and can use your library. If you dont have a lib file you can still use the dll by importing it yourself. During your applications startup you can explicitly load the dll by calling LoadLibrary (see: http://msdn.microsoft.com/en-us/library/ms684175(VS.85).aspx for more info)

Cheers!

EDIT

Remember to use #include < Foo.h > as opposed to #include "foo.h". The former searches the include path. The latter uses the local project files.

How to make a function wait until a callback has been called using node.js

One way to achieve this is to wrap the API call into a promise and then use await to wait for the result.

// let's say this is the API function with two callbacks,
// one for success and the other for error
function apiFunction(query, successCallback, errorCallback) {
    if (query == "bad query") {
        errorCallback("problem with the query");
    }
    successCallback("Your query was <" + query + ">");
}

// myFunction wraps the above API call into a Promise
// and handles the callbacks with resolve and reject
function apiFunctionWrapper(query) {
    return new Promise((resolve, reject) => {
        apiFunction(query,(successResponse) => {
            resolve(successResponse);
        }, (errorResponse) => {
            reject(errorResponse);
        });
    });
}

// now you can use await to get the result from the wrapped api function
// and you can use standard try-catch to handle the errors
async function businessLogic() {
    try {
        const result = await apiFunctionWrapper("query all users");
        console.log(result);
        
        // the next line will fail
        const result2 = await apiFunctionWrapper("bad query");
    } catch(error) {
        console.error("ERROR:" + error);
    }
}

// call the main function
businessLogic();

Output:

Your query was <query all users>
ERROR:problem with the query

Removing index column in pandas when reading a csv

You can set one of the columns as an index in case it is an "id" for example. In this case the index column will be replaced by one of the columns you have chosen.

df.set_index('id', inplace=True)

What is CMake equivalent of 'configure --prefix=DIR && make all install '?

Regarding Bruce Adams answer:

Your answer creates dangerous confusion. DESTDIR is intended for installs out of the root tree. It allows one to see what would be installed in the root tree if one did not specify DESTDIR. PREFIX is the base directory upon which the real installation is based.

For example, PREFIX=/usr/local indicates that the final destination of a package is /usr/local. Using DESTDIR=$HOME will install the files as if $HOME was the root (/). If, say DESTDIR, was /tmp/destdir, one could see what 'make install' would affect. In that spirit, DESTDIR should never affect the built objects.

A makefile segment to explain it:

install:
    cp program $DESTDIR$PREFIX/bin/program

Programs must assume that PREFIX is the base directory of the final (i.e. production) directory. The possibility of symlinking a program installed in DESTDIR=/something only means that the program does not access files based upon PREFIX as it would simply not work. cat(1) is a program that (in its simplest form) can run from anywhere. Here is an example that won't:

prog.pseudo.in:
    open("@prefix@/share/prog.db")
    ...

prog:
    sed -e "s/@prefix@/$PREFIX/" prog.pseudo.in > prog.pseudo
    compile prog.pseudo

install:
    cp prog $DESTDIR$PREFIX/bin/prog
    cp prog.db $DESTDIR$PREFIX/share/prog.db

If you tried to run prog from elsewhere than $PREFIX/bin/prog, prog.db would never be found as it is not in its expected location.

Finally, /etc/alternatives really does not work this way. There are symlinks to programs installed in the root tree (e.g. vi -> /usr/bin/nvi, vi -> /usr/bin/vim, etc.).

Get first day of week in PHP?

Another way to do it....

$year = '2014';
$month = '02';
$day = '26';

$date = DateTime::createFromFormat('Y-m-d H:i:s', $year . '-' . $month . '-' . $day . '00:00:00');
$day = date('w', $date->getTimestamp());

// 0=Sunday 6=Saturday
if($day!=0){

   $newdate = $date->getTimestamp() - $day * 86400;  //86400 seconds in a day

   // Look for DST change 
   if($old = date('I', $date->getTimestamp()) != $new = date('I', $newdate)){
       if($old == 0){
           $newdate -= 3600;  //3600 seconds in an hour
       } else {
           $newdate += 3600;
       }
   }

   $date->setTimestamp($newdate);
}

echo $date->format('D Y-m-d H:i:s');

Python Linked List

The following is what I came up with. It's similer to Riccardo C.'s, in this thread, except it prints the numbers in order instead of in reverse. I also made the LinkedList object a Python Iterator in order to print the list out like you would a normal Python list.

class Node:

    def __init__(self, data=None):
        self.data = data
        self.next = None

    def __str__(self):
        return str(self.data)


class LinkedList:

    def __init__(self):
        self.head = None
        self.curr = None
        self.tail = None

    def __iter__(self):
        return self

    def next(self):
        if self.head and not self.curr:
            self.curr = self.head
            return self.curr
        elif self.curr.next:
            self.curr = self.curr.next
            return self.curr
        else:
            raise StopIteration

    def append(self, data):
        n = Node(data)
        if not self.head:
            self.head = n
            self.tail = n
        else:
            self.tail.next = n
            self.tail = self.tail.next


# Add 5 nodes
ll = LinkedList()
for i in range(1, 6):
    ll.append(i)

# print out the list
for n in ll:
    print n

"""
Example output:
$ python linked_list.py
1
2
3
4
5
"""

How do I get the name of a Ruby class?

Here's the correct answer, extracted from comments by Daniel Rikowski and pseidemann. I'm tired of having to weed through comments to find the right answer...

If you use Rails (ActiveSupport):

result.class.name.demodulize

If you use POR (plain-ol-Ruby):

result.class.name.split('::').last

overlay opaque div over youtube iframe

Is the opaque overlay for aesthetic purposes?

If so, you can use:

#overlay {
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        left: 0;
        z-index: 50;
        background: #000;
        pointer-events: none;
        opacity: 0.8;
        color: #fff;
}

'pointer-events: none' will change the overlay behavior so that it can be physically opaque. Of course, this will only work in good browsers.

Using python's eval() vs. ast.literal_eval()?

datamap = eval(input('Provide some data here: ')) means that you actually evaluate the code before you deem it to be unsafe or not. It evaluates the code as soon as the function is called. See also the dangers of eval.

ast.literal_eval raises an exception if the input isn't a valid Python datatype, so the code won't be executed if it's not.

Use ast.literal_eval whenever you need eval. You shouldn't usually evaluate literal Python statements.

How to format a duration in java? (e.g format H:MM:SS)

My library Time4J offers a pattern-based solution (similar to Apache DurationFormatUtils, but more flexible):

Duration<ClockUnit> duration =
    Duration.of(-573421, ClockUnit.SECONDS) // input in seconds only
    .with(Duration.STD_CLOCK_PERIOD); // performs normalization to h:mm:ss-structure
String fs = Duration.formatter(ClockUnit.class, "+##h:mm:ss").format(duration);
System.out.println(fs); // output => -159:17:01

This code demonstrates the capabilities to handle hour overflow and sign handling, see also the API of duration-formatter based on pattern.

PHP: Return all dates between two dates in an array

To make Mostafa's answer complete, this is definietly the simplest and most efficient way to do it:

function getDatesFromRange($start_date, $end_date, $date_format = 'Y-m-d')
   {
      $dates_array = array();
      for ($x = strtotime($start_date); $x <= strtotime($end_date); $x += 86400) {
         array_push($dates_array, date($date_format, $x));
      }

      return $dates_array;
   }

   // see the dates in the array
   print_r( getDatesFromRange('2017-02-09', '2017-02-19') );

You can even change the default output date format if you add a third parameter when you call the function, otherwise it will use the default format that's been set as 'Y-m-d'.

I hope it helps :)

When should I use Lazy<T>?

A great real-world example of where lazy loading comes in handy is with ORM's (Object Relation Mappers) such as Entity Framework and NHibernate.

Say you have an entity Customer which has properties for Name, PhoneNumber, and Orders. Name and PhoneNumber are regular strings but Orders is a navigation property that returns a list of every order the customer ever made.

You often might want to go through all your customer's and get their name and phone number to call them. This is a very quick and simple task, but imagine if each time you created a customer it automatically went and did a complex join to return thousands of orders. The worst part is that you aren't even going to use the orders so it is a complete waste of resources!

This is the perfect place for lazy loading because if the Order property is lazy it will not go fetch all the customer's order unless you actually need them. You can enumerate the Customer objects getting only their Name and Phone Number while the Order property is patiently sleeping, ready for when you need it.

SQL select join: is it possible to prefix all columns as 'prefix.*'?

It seems the answer to your question is no, however one hack you can use is to assign a dummy column to separate each new table. This works especially well if you're looping through a result set for a list of columns in a scripting language such as Python or PHP.

SELECT '' as table1_dummy, table1.*, '' as table2_dummy, table2.*, '' as table3_dummy, table3.* FROM table1
JOIN table2 ON table2.table1id = table1.id
JOIN table3 ON table3.table1id = table1.id

I realize this doesn't answer your question exactly, but if you're a coder this is a great way to separate tables with duplicate column names. Hope this helps somebody.

Error:com.android.tools.aapt2.Aapt2Exception: AAPT2 error: check logs for details

In my case I have update compile SDK and build SDK version to 30 and added

 requestLegacyPermission=true 

in android manifest file, as I was accessing the storage for reading and writing. later when I edited the compile SDK and build SDK version and get back to version 26 then I forgot to remove

requestLegacyPermission=true 

in Manifest file.

Reason:

requestLegacyPermission was introduced in Android 10 so that's the reason Manifest was not recognizing this as I updated Compile SDK and Build SDK to 26.

Submit button doesn't work

Hello from the future.

For clarity, I just wanted to add (as this was pretty high up in google) - we can now use

<button type="submit">Upload Stuff</button>

And to reset a form

<button type="reset" value="Reset">Reset</button>

Check out button types

We can also attach buttons to submit forms like this:

<button type="submit" form="myform" value="Submit">Submit</button>

How do I set the eclipse.ini -vm option?

Anything after the "vmargs" is taken to be vm arguments. Just make sure it's before that, which is the last piece in eclipse.ini.

Read Post Data submitted to ASP.Net Form

Read the Request.Form NameValueCollection and process your logic accordingly:

NameValueCollection nvc = Request.Form;
string userName, password;
if (!string.IsNullOrEmpty(nvc["txtUserName"]))
{
  userName = nvc["txtUserName"];
}

if (!string.IsNullOrEmpty(nvc["txtPassword"]))
{
  password = nvc["txtPassword"];
}

//Process login
CheckLogin(userName, password);

... where "txtUserName" and "txtPassword" are the Names of the controls on the posting page.

How can I convert an HTML element to a canvas element?

the next code can be used in 2 modes, mode 1 save the html code to a image, mode 2 save the html code to a canvas.

this code work with the library: https://github.com/tsayen/dom-to-image

*the "id_div" is the id of the element html that you want to transform.

**the "canvas_out" is the id of the div that will contain the canvas so try this code. :

   function Guardardiv(id_div){

      var mode = 2 // default 1 (save to image), mode 2 = save to canvas
      console.log("Process start");
      var node = document.getElementById(id_div);
      // get the div that will contain the canvas
      var canvas_out = document.getElementById('canvas_out');
      var canvas = document.createElement('canvas');
      canvas.width = node.scrollWidth;
      canvas.height = node.scrollHeight;

      domtoimage.toPng(node).then(function (pngDataUrl) {
          var img = new Image();
          img.onload = function () {
          var context = canvas.getContext('2d');
          context.drawImage(img, 0, 0);
        };

        if (mode == 1){ // save to image
             downloadURI(pngDataUrl, "salida.png");
        }else if (mode == 2){ // save to canvas
          img.src = pngDataUrl;
          canvas_out.appendChild(img);

        }
      console.log("Process finish");
    });

    }

so, if you want to save to image just add this function:

    function downloadURI(uri, name) {
        var link = document.createElement("a");

        link.download = name;
        link.href = uri;
        document.body.appendChild(link);
        link.click();   
    }

Example of use:

 <html>
 <head>
 </script src="/dom-to-image.js"></script>
 </head> 
 <body>
 <div id="container">
   All content that want to transform
  </div>
  <button onclick="Guardardiv('container');">Convert<button> 

 <!-- if use mode 2 -->
 <div id="canvas_out"></div>
 </html>

Comment if that work. Comenten si les sirvio :)

How to force NSLocalizedString to use a specific language

I wanted to add support for a language that isn't officially supported by iOS (not listed in Language section under system settings). By following the Apple's Internationalization Tutorial and few hints here by Brian Webster and geon, I came up with this piece of code (put it in main.m):

int main(int argc, char * argv[]) {
    @autoreleasepool {
        // Grab regional settings locale, for Slovenian this is either sl_SI or en_SI
        NSLocale *locale = [NSLocale currentLocale];
        NSString *ll = [locale localeIdentifier]; // sl_SI

        // Grab the first part of language identifier
        NSArray *comp = [ll componentsSeparatedByString:@"_"];
        NSString *ll1 = @"en";
        if (comp.count > 0) {
            ll1 = comp[0]; // sl, en, ...
        }
        // Check if we already saved language (user can manually change it inside app for example)
        if (![[NSUserDefaults standardUserDefaults] objectForKey:@"SelectedLanguage"]) {
            //   Slovenian (Slovenia),            Slovenia
            if ([ll isEqualToString:@"sl_SI"] || [ll isEqualToString:@"en_SI"]) {
                ll1 = @"sl-SI"; // This is the part of localized path for Slovenian language that Xcode generates
            }
            // Add more unsupported languages here...

            [[NSUserDefaults standardUserDefaults] setObject:ll1 forKey:@"SelectedLanguage"]; // Save language
        }
        else {
            // Restore language as we have previously saved it
            ll1 = [[NSUserDefaults standardUserDefaults] objectForKey:@"SelectedLanguage"];
        }
        // Overwrite NSLocalizedString and StoryBoard language preference
        [[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObjects:ll1, @"en", @"fr", nil] forKey:@"AppleLanguages"];
        // Make sure settings are stored to disk
        [[NSUserDefaults standardUserDefaults] synchronize];

        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
    }
}

This works well for both Storyboard and NSLocalizedString code. The code assumes that user will have an option to manually change language inside app later on.

Of course, don't forget to add proper Storyboard translations and Localizable.strings translations (see link to Apple page above for how to do that).

"Large data" workflows using pandas

I'd like to point out the Vaex package.

Vaex is a python library for lazy Out-of-Core DataFrames (similar to Pandas), to visualize and explore big tabular datasets. It can calculate statistics such as mean, sum, count, standard deviation etc, on an N-dimensional grid up to a billion (109) objects/rows per second. Visualization is done using histograms, density plots and 3d volume rendering, allowing interactive exploration of big data. Vaex uses memory mapping, zero memory copy policy and lazy computations for best performance (no memory wasted).

Have a look at the documentation: https://vaex.readthedocs.io/en/latest/ The API is very close to the API of pandas.

Is it possible to run JavaFX applications on iOS, Android or Windows Phone 8?

Background

Invariant's answer is a good resource for how everything was started and what was the state of JavaFX on embedded and mobile in beginning of 2014. But, a lot has changed since then and the users who stumble on this thread do not get the updated information.

Most of my points are related to Invariant's answer, so I would suggest to go through it first.

Current Status of JavaFX on Mobile / Embedded

UPDATE

JavaFXPorts has been deprecated. Gluon Mobile now uses GraalVM underneath. There are multiple advantages of using GraalVM. Please check this blogpost from Gluon. The IDE plugins have been updated to use Gluon Client plugins which leverages GraalVM to AOT compile applications for Android/iOS.

Old answer with JavaFXPorts

Some bad news first:

Now, some good news:

  • JavaFX still runs on Android, iOS and most of the Embedded devices
  • JavaFXPorts SDK for android, iOS and embedded devices can be downloaded from here
  • JavaFXPorts project is still thriving and it is easier than ever to run JavaFX on mobile devices, all thanks to the IDE plugins that is built on top of these SDKs and gets you started in a few minutes without the hassle of installing any SDK
  • JavaFX 3D is now supported on mobile devices
  • GluonVM to replace RoboVM enabling Java 9 support for mobile developers. Yes, you heard it right.
  • Mobile Project has been launched by Oracle to support JDK on all major mobile platforms. It should support JavaFX as well ;)

How to get started

If you are not the DIY kind, I would suggest to install the IDE plugin on your favourite IDE and get started.

Most of the documentation on how to get started can be found here and some of the samples can be found here.

Autocompletion of @author in Intellij

You can work around that via a Live Template. Go to Settings -> Live Template, click the "Add"-Button (green plus on the right).

In the "Abbreviation" field, enter the string that should activate the template (e.g. @a), and in the "Template Text" area enter the string to complete (e.g. @author - My Name). Set the "Applicable context" to Java (Comments only maybe) and set a key to complete (on the right).

I tested it and it works fine, however IntelliJ seems to prefer the inbuild templates, so "@a + Tab" only completes "author". Setting the completion key to Space worked however.

To change the user name that is automatically inserted via the File Templates (when creating a class for example), can be changed by adding

-Duser.name=Your name

to the idea.exe.vmoptions or idea64.exe.vmoptions (depending on your version) in the IntelliJ/bin directory.

enter image description here

Restart IntelliJ

Receiving login prompt using integrated windows authentication

I encountered the same credential prompting issue, and did a quick search and nothing on the internet would fix it. It took some time to find the problem, a silly one.

In IIS -> Advance Setting -> Physical Path Credential (is empty)

As soon as i added a machine ID (domain/user) that has access to the VM/server, the password prompting would stop.

Hope this helps

Why is "forEach not a function" for this object?

Object does not have forEach, it belongs to Array prototype. If you want to iterate through each key-value pair in the object and take the values. You can do this:

Object.keys(a).forEach(function (key){
    console.log(a[key]);
});

Usage note: For an object v = {"cat":"large", "dog": "small", "bird": "tiny"};, Object.keys(v) gives you an array of the keys so you get ["cat","dog","bird"]

Border around tr element doesn't show?

Add this to the stylesheet:

table {
  border-collapse: collapse;
}

JSFiddle.

The reason why it behaves this way is actually described pretty well in the specification:

There are two distinct models for setting borders on table cells in CSS. One is most suitable for so-called separated borders around individual cells, the other is suitable for borders that are continuous from one end of the table to the other.

... and later, for collapse setting:

In the collapsing border model, it is possible to specify borders that surround all or part of a cell, row, row group, column, and column group.

Where are shared preferences stored?

Just to save some of you time...

On my Galaxy S v.2.3.3 Shared Preferences are not stored in:/data/data/YOUR_PACKAGE_NAME/shared_prefs/YOUR_PREFS_NAME.xml

but are now located in: /dbdata/databases/YOUR_PACKAGE_NAME/shared_prefs/YOUR_PREFS_NAME.xml

I believe they changed this in 2.3

Convert file: Uri to File in Android

public String getRealPathFromURI(Uri uri) {

    String result;
    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
    if (cursor == null) {
        result = uri.getPath();
        cursor.close();
        return result;
    }
    cursor.moveToFirst();
    int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
    result = cursor.getString(idx);
    cursor.close();
    return result;
}

Then using to get file from URI :

        File finalFile = newFile(getRealPathFromURI(uri));

--HOPE CAN HELP YOU----

BigDecimal to string

By using below method you can convert java.math.BigDecimal to String.

   BigDecimal bigDecimal = new BigDecimal("10.0001");
   String bigDecimalString = String.valueOf(bigDecimal.doubleValue());
   System.out.println("bigDecimal value in String: "+bigDecimalString);

Output:
bigDecimal value in String: 10.0001

Maximum size for a SQL Server Query? IN clause? Is there a Better Approach

Can you load the GUIDs into a scratch table then do a

... WHERE var IN SELECT guid FROM #scratchtable

Comparing two vectors in an if statement

I'd probably use all.equal and which to get the information you want. It's not recommended to use all.equal in an if...else block for some reason, so we wrap it in isTRUE(). See ?all.equal for more:

foo <- function(A,B){
  if (!isTRUE(all.equal(A,B))){
    mismatches <- paste(which(A != B), collapse = ",")
    stop("error the A and B does not match at the following columns: ", mismatches )
  } else {
    message("Yahtzee!")
  }
}

And in use:

> foo(A,A)
Yahtzee!
> foo(A,B)
Yahtzee!
> foo(A,C)
Error in foo(A, C) : 
  error the A and B does not match at the following columns: 2,4

Returning data from Axios API

you can populate the data you want with a simple callback function, let's say we have a list named lst that we want to populate, we have a function that pupulates pupulates list,

const lst = [];  
const populateData = (data) => {lst.push(data)} 

now we can pass the callback function to the function which is making the axios call and we can pupulate the list when we get data from response.

now we make our function that makes the request and pass populateData as a callback function.

function axiosTest (populateData) {
        axios.get(url)
       .then(function(response){
               populateData(response.data);
        })
        .catch(function(error){
               console.log(error);
         });
}   

Why do I need to explicitly push a new branch?

I couldn't find a rationale by the original developers this quickly, but I can give you an educated guess based on a few years of Git experience.

No, not every branch is something you want to push to the outside world. It might represent a private experiment.

Moreover, where should git push send all the branches? Git can work with multiple remotes and you may want to have different sets of branches on each. E.g. a central project GitHub repo may have release branches; a GitHub fork may have topic branches for review; and a local Git server may have branches containing local configuration. If git push would push all branches to the remote that the current branch tracks, this kind of scheme would be easy to screw up.

source of historical stock data

Mathematica nowoadays also offers access to both current and historical stock prices, see http://reference.wolfram.com/mathematica/ref/FinancialData.html , if you happen to have a copy of it.

How to convert CSV file to multiline JSON?

The problem with your desired output is that it is not valid json document,; it's a stream of json documents!

That's okay, if its what you need, but that means that for each document you want in your output, you'll have to call json.dumps.

Since the newline you want separating your documents is not contained in those documents, you're on the hook for supplying it yourself. So we just need to pull the loop out of the call to json.dump and interpose newlines for each document written.

import csv
import json

csvfile = open('file.csv', 'r')
jsonfile = open('file.json', 'w')

fieldnames = ("FirstName","LastName","IDNumber","Message")
reader = csv.DictReader( csvfile, fieldnames)
for row in reader:
    json.dump(row, jsonfile)
    jsonfile.write('\n')

Table fixed header and scrollable body

_x000D_
_x000D_
table {_x000D_
_x000D_
    display: block;_x000D_
}_x000D_
_x000D_
thead, tbody {_x000D_
    display: block;_x000D_
}_x000D_
tbody {_x000D_
    position: absolute;_x000D_
    height: 150px;_x000D_
    overflow-y: scroll;_x000D_
}_x000D_
td, th {_x000D_
    min-width: 100px !important;_x000D_
    height: 25px !important;_x000D_
    overflow:hidden !important;_x000D_
    text-overflow: ellipsis !important;_x000D_
    max-width: 100px !important;_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.0/jquery.min.js"></script>_x000D_
_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script>_x000D_
_x000D_
<div class="container" style="position:fixed;height:180px;overflow-x:scroll;overflow-y:hidden">_x000D_
_x000D_
_x000D_
<table>_x000D_
         <thead>_x000D_
        <tr>_x000D_
             <th>Col1</th>_x000D_
            <th>Col2</th>_x000D_
            <th>Username</th>_x000D_
            <th>Password</th>_x000D_
            <th>First Name</th>_x000D_
            <th>Last Name</th>_x000D_
            <th>Col16</th>_x000D_
            <th>Col7</th>_x000D_
            <th>Col8</th>_x000D_
            <th>Col9</th>_x000D_
            <th>Col10</th>_x000D_
            <th>Col11</th>_x000D_
            <th>Col12</th>_x000D_
            <th>Col13</th>_x000D_
            <th>Col14</th>_x000D_
            <th>Col15</th>_x000D_
            <th>Col16</th>_x000D_
            <th>Col17</th>_x000D_
            <th>Col18</th>_x000D_
        </tr>_x000D_
              </thead>_x000D_
         <tbody>_x000D_
         </tbody>_x000D_
          <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
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                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
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            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
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                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
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                      <td>Title</td>_x000D_
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            <td>Long Value</td>_x000D_
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                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
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            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
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                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
                    <tr>_x000D_
          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
          </tr>_x000D_
          _x000D_
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          <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
                      <td>Title</td>_x000D_
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                      <td>Title</td>_x000D_
            <td>Long Value</td>_x000D_
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          </tr>_x000D_
          _x000D_
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How to count certain elements in array?

I believe what you are looking for is functional approach

    const arr = ['a', 'a', 'b', 'g', 'a', 'e'];
    const count = arr.filter(elem => elem === 'a').length;
    console.log(count); // Prints 3

elem === 'a' is the condition, replace it with your own.

Compare two Timestamp in java

if(mytime.after(fromtime) && mytime.before(totime))
  //mytime is in between

Where does git config --global get written to?

It might be useful to note (for *nix platforms): some types of global git configuration/information are stored in /usr/share/git-core/, such as git autocompletion scripts and the following (default) hooks:

  • applypatch-msg
  • post-update
  • pre-commit
  • prepare-commit-msg
  • commit-msg
  • pre-applypatch
  • pre-rebase
  • update

Each of these can contain their own set of commands to execute, at the time described by their respective filenames.

How do I sort a VARCHAR column in SQL server that contains numbers?

This query is helpful for you. In this query, a column has data type varchar is arranged by good order.For example- In this column data are:- G1,G34,G10,G3. So, after running this query, you see the results: - G1,G10,G3,G34.

SELECT *,
       (CASE WHEN ISNUMERIC(column_name) = 1 THEN 0 ELSE 1 END) IsNum
FROM table_name 
ORDER BY IsNum, LEN(column_name), column_name;

Volley - POST/GET parameters

For the GET parameters there are two alternatives:

First: As suggested in a comment bellow the question you can just use String and replace the parameters placeholders with their values like:

String uri = String.format("http://somesite.com/some_endpoint.php?param1=%1$s&param2=%2$s",
                           num1,
                           num2);

StringRequest myReq = new StringRequest(Method.GET,
                                        uri,
                                        createMyReqSuccessListener(),
                                        createMyReqErrorListener());
queue.add(myReq);

where num1 and num2 are String variables that contain your values.

Second: If you are using newer external HttpClient (4.2.x for example) you can use URIBuilder to build your Uri. Advantage is that if your uri string already has parameters in it it will be easier to pass it to the URIBuilder and then use ub.setQuery(URLEncodedUtils.format(getGetParams(), "UTF-8")); to add your additional parameters. That way you will not bother to check if "?" is already added to the uri or to miss some & thus eliminating a source for potential errors.

For the POST parameters probably sometimes will be easier than the accepted answer to do it like:

StringRequest myReq = new StringRequest(Method.POST,
                                        "http://somesite.com/some_endpoint.php",
                                        createMyReqSuccessListener(),
                                        createMyReqErrorListener()) {

    protected Map<String, String> getParams() throws com.android.volley.AuthFailureError {
        Map<String, String> params = new HashMap<String, String>();
        params.put("param1", num1);
        params.put("param2", num2);
        return params;
    };
};
queue.add(myReq);

e.g. to just override the getParams() method.

You can find a working example (along with many other basic Volley examples) in the Andorid Volley Examples project.

MySQL - Meaning of "PRIMARY KEY", "UNIQUE KEY" and "KEY" when used together while creating a table

A key is just a normal index. A way over simplification is to think of it like a card catalog at a library. It points MySQL in the right direction.

A unique key is also used for improved searching speed, but it has the constraint that there can be no duplicated items (there are no two x and y where x is not y and x == y).

The manual explains it as follows:

A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. This constraint does not apply to NULL values except for the BDB storage engine. For other engines, a UNIQUE index permits multiple NULL values for columns that can contain NULL. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix.

A primary key is a 'special' unique key. It basically is a unique key, except that it's used to identify something.

The manual explains how indexes are used in general: here.

In MSSQL, the concepts are similar. There are indexes, unique constraints and primary keys.

Untested, but I believe the MSSQL equivalent is:

CREATE TABLE tmp (
  id int NOT NULL PRIMARY KEY IDENTITY,
  uid varchar(255) NOT NULL CONSTRAINT uid_unique UNIQUE,
  name varchar(255) NOT NULL,
  tag int NOT NULL DEFAULT 0,
  description varchar(255),
);

CREATE INDEX idx_name ON tmp (name);
CREATE INDEX idx_tag ON tmp (tag);

Edit: the code above is tested to be correct; however, I suspect that there's a much better syntax for doing it. Been a while since I've used SQL server, and apparently I've forgotten quite a bit :).

What's the u prefix in a Python string?

You're right, see 3.1.3. Unicode Strings.

It's been the syntax since Python 2.0.

Python 3 made them redundant, as the default string type is Unicode. Versions 3.0 through 3.2 removed them, but they were re-added in 3.3+ for compatibility with Python 2 to aide the 2 to 3 transition.

How to format a URL to get a file from Amazon S3?

Its actually formulated more like:

https://<bucket-name>.s3.amazonaws.com/<key>

See here

IPython Notebook save location

Just cd to your working folder and then start the IPython notebook server. This way you can be mobile.

Map isn't showing on Google Maps JavaScript API v3 when nested in a div tag

In my case I was getting the grey background and it turned out to be inclusion of a zoom value in the map options. Yup, makes no sense.

How to open maximized window with Javascript?

The best solution I could find at present time to open a window maximized is (Internet Explorer 11, Chrome 49, Firefox 45):

  var popup = window.open("your_url", "popup", "fullscreen");
  if (popup.outerWidth < screen.availWidth || popup.outerHeight < screen.availHeight)
  {
    popup.moveTo(0,0);
    popup.resizeTo(screen.availWidth, screen.availHeight);
  }

see https://jsfiddle.net/8xwocrp6/7/

Note 1: It does not work on Edge (13.1058686). Not sure whether it's a bug or if it's as designed (I've filled a bug report, we'll see what they have to say about it). Here is a workaround:

if (navigator.userAgent.match(/Edge\/\d+/g))
{
    return window.open("your_url", "popup", "width=" + screen.width + ",height=" + screen.height);
}

Note 2: moveTo or resizeTo will not work (Access denied) if the window you are opening is on another domain.

How do I connect to a terminal to a serial-to-USB device on Ubuntu 10.10 (Maverick Meerkat)?

You will need to set the permissions every time you plug the converter in. I use PuTTY to connect. In order to do so, I have created a little Bash script to sort out the permissions and launch PuTTY:

#!/bin/bash
sudo chmod 666 /dev/ttyUSB0

putty

P.S. I would never recommend that permissions are set to 777.

Input length must be multiple of 16 when decrypting with padded cipher

This is a very old question, but my answer may help someone.

  • In the encrypt method, don't forget to encode your string to Base64
  • In the decrypt method, don't forget to decode your string to Base64

Below is the working code

    import java.util.Arrays;
    import java.util.Base64;

    import javax.crypto.Cipher;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.SecretKeySpec;

    public class EncryptionDecryptionUtil {

    public static String encrypt(final String secret, final String data) {


        byte[] decodedKey = Base64.getDecoder().decode(secret);

        try {
            Cipher cipher = Cipher.getInstance("AES");
            // rebuild key using SecretKeySpec
            SecretKey originalKey = new SecretKeySpec(Arrays.copyOf(decodedKey, 16), "AES");
            cipher.init(Cipher.ENCRYPT_MODE, originalKey);
            byte[] cipherText = cipher.doFinal(data.getBytes("UTF-8"));
            return Base64.getEncoder().encodeToString(cipherText);
        } catch (Exception e) {
            throw new RuntimeException(
                    "Error occured while encrypting data", e);
        }

    }

    public static String decrypt(final String secret,
            final String encryptedString) {


        byte[] decodedKey = Base64.getDecoder().decode(secret);

        try {
            Cipher cipher = Cipher.getInstance("AES");
            // rebuild key using SecretKeySpec
            SecretKey originalKey = new SecretKeySpec(Arrays.copyOf(decodedKey, 16), "AES");
            cipher.init(Cipher.DECRYPT_MODE, originalKey);
            byte[] cipherText = cipher.doFinal(Base64.getDecoder().decode(encryptedString));
            return new String(cipherText);
        } catch (Exception e) {
            throw new RuntimeException(
                    "Error occured while decrypting data", e);
        }
    }


    public static void main(String[] args) {

        String data = "This is not easy as you think";
        String key = "---------------------------------";
        String encrypted = encrypt(key, data);
        System.out.println(encrypted);
        System.out.println(decrypt(key, encrypted));
      }
  }

For Generating Key you can use below class

    import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;

import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;

public class SecretKeyGenerator {

    public static void main(String[] args) throws NoSuchAlgorithmException {

        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");

        SecureRandom secureRandom = new SecureRandom();
        int keyBitSize = 256;
        keyGenerator.init(keyBitSize, secureRandom);

        SecretKey secretKey = keyGenerator.generateKey();

 System.out.println(Base64.getEncoder().encodeToString(secretKey.getEncoded()));
    }

}

Simple way to sort strings in the (case sensitive) alphabetical order

The simple way to solve the problem is to use ComparisonChain from Guava http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/collect/ComparisonChain.html

private static Comparator<String> stringAlphabeticalComparator = new Comparator<String>() {
        public int compare(String str1, String str2) {
            return ComparisonChain.start().
                                compare(str1,str2, String.CASE_INSENSITIVE_ORDER).
                                compare(str1,str2).
                                result();
         }
 };
Collections.sort(list, stringAlphabeticalComparator);

The first comparator from the chain will sort strings according to the case insensitive order, and the second comparator will sort strings according to the case insensitive order. As excepted strings appear in the result according to the alphabetical order:

"AA","Aa","aa","Development","development"

How can I hide a TD tag using inline JavaScript or CSS?

Same way you'd hide anything: visibility: hidden;

Converting string from snake_case to CamelCase in Ruby

Most of the other methods listed here are Rails specific. If you want do do this with pure Ruby, the following is the most concise way I've come up with (thanks to @ulysse-bn for the suggested improvement)

x="this_should_be_camel_case"
x.gsub(/(?:_|^)(\w)/){$1.upcase}
    #=> "ThisShouldBeCamelCase"

'if' in prolog?

There are essentially three different ways how to express something like if-then-else in Prolog. To compare them consider char_class/2. For a and b the class should be ab and other for all other terms. One could write this clumsily like so:

char_class(a, ab).
char_class(b, ab).
char_class(X, other) :-
   dif(X, a),
   dif(X, b).

?- char_class(Ch, Class).
   Ch = a, Class = ab
;  Ch = b, Class = ab
;  Class = other,
   dif(Ch, a), dif(Ch, b).

To write things more compactly, an if-then-else construct is needed. Prolog has a built-in one:

?- ( ( Ch = a ; Ch = b ) -> Class = ab ; Class = other ).
   Ch = a, Class = ab.

While this answer is sound, it is incomplete. Just the first answer from ( Ch = a ; Ch = b ) is given. The other answers are chopped away. Not very relational, indeed.

A better construct, often called a "soft cut" (don't believe the name, a cut is a cut is a cut), gives slightly better results (this is in YAP):

?- ( ( Ch = a ; Ch = b ) *-> Class = ab ; Class = other ).
   Ch = a, Class = ab
;  Ch = b, Class = ab.

Alternatively, SICStus has if/3 with very similar semantics:

?- if( ( Ch = a ; Ch = b ), Class = ab , Class = other ).
   Ch = a, Class = ab
;  Ch = b, Class = ab.

So the last answer is still suppressed. Now enter library(reif) for SICStus, YAP, and SWI. Install it and say:

?- use_module(library(reif)).

?- if_( ( Ch = a ; Ch = b ), Class = ab , Class = other ).
   Ch = a, Class = ab
;  Ch = b, Class = ab
;  Class = other,
   dif(Ch, a), dif(Ch, b).

Note that all the if_/3 is compiled away to a wildly nested if-then-else for

char_class(Ch, Class) :-
   if_( ( Ch = a ; Ch = b ), Class = ab , Class = other ).

which expands in YAP 6.3.4 to:

char_class(A,B) :-
   ( A\=a
   ->
     ( A\=b
     ->
       B=other
     ;
       ( A==b
       ->
         B=ab
       )
     ;
       A=b,
       B=ab
     ;
       dif(A,b),
       B=other
     )
   ;
     ( A==a
     ->
       B=ab
     )
   ;
     A=a,
     B=ab
   ;
     dif(A,a),
     ( A\=b
     ->
       B=other
     ;
       ( A==b
       ->
         B=ab
       )
     ;
       A=b,
       B=ab
     ;
       dif(A,b),
       B=other
     )
   ).

"sed" command in bash

It reads Hello World (cat), replaces all (g) occurrences of % by $ and (over)writes it to /etc/init.d/dropbox as root.

Getting an odd error, SQL Server query using `WITH` clause

It should be legal to put a semicolon directly before the WITH keyword.

How to open child forms positioned within MDI parent in VB.NET?

Try Making the Child Form's StartPosition Property set to Center Parent. This you can select from the form Properties.

How to give color to each class in scatter plot in R?

Here is how I do it in 2018. Who knows, maybe an R newbie will see it one day and fall in love with ggplot2.

library(ggplot2)

ggplot(data = iris, aes(Petal.Length, Petal.Width, color = Species)) +
  geom_point() +
  scale_color_manual(values = c("setosa" = "red", "versicolor" = "blue", "virginica" = "yellow"))

UNIX export command

export is a built-in command of the bash shell and other Bourne shell variants. It is used to mark a shell variable for export to child processes.

Get to UIViewController from UIView?

I stumbled upon a situation where I have a small component I want to reuse, and added some code in a reusable view itself(it's really not much more than a button that opens a PopoverController).

While this works fine in the iPad (the UIPopoverController presents itself, therefor needs no reference to a UIViewController), getting the same code to work means suddenly referencing your presentViewController from your UIViewController. Kinda inconsistent right?

Like mentioned before, it's not the best approach to have logic in your UIView. But it felt really useless to wrap the few lines of code needed in a separate controller.

Either way, here's a swift solution, which adds a new property to any UIView:

extension UIView {

    var viewController: UIViewController? {

        var responder: UIResponder? = self

        while responder != nil {

            if let responder = responder as? UIViewController {
                return responder
            }
            responder = responder?.nextResponder()
        }
        return nil
    }
}

Why am I getting an error "Object literal may only specify known properties"?

As of TypeScript 1.6, properties in object literals that do not have a corresponding property in the type they're being assigned to are flagged as errors.

Usually this error means you have a bug (typically a typo) in your code, or in the definition file. The right fix in this case would be to fix the typo. In the question, the property callbackOnLoactionHash is incorrect and should have been callbackOnLocationHash (note the mis-spelling of "Location").

This change also required some updates in definition files, so you should get the latest version of the .d.ts for any libraries you're using.

Example:

interface TextOptions {
    alignment?: string;
    color?: string;
    padding?: number;
}
function drawText(opts: TextOptions) { ... }
drawText({ align: 'center' }); // Error, no property 'align' in 'TextOptions'

But I meant to do that

There are a few cases where you may have intended to have extra properties in your object. Depending on what you're doing, there are several appropriate fixes

Type-checking only some properties

Sometimes you want to make sure a few things are present and of the correct type, but intend to have extra properties for whatever reason. Type assertions (<T>v or v as T) do not check for extra properties, so you can use them in place of a type annotation:

interface Options {
    x?: string;
    y?: number;
}

// Error, no property 'z' in 'Options'
let q1: Options = { x: 'foo', y: 32, z: 100 };
// OK
let q2 = { x: 'foo', y: 32, z: 100 } as Options;
// Still an error (good):
let q3 = { x: 100, y: 32, z: 100 } as Options;

These properties and maybe more

Some APIs take an object and dynamically iterate over its keys, but have 'special' keys that need to be of a certain type. Adding a string indexer to the type will disable extra property checking

Before

interface Model {
  name: string;
}
function createModel(x: Model) { ... }

// Error
createModel({name: 'hello', length: 100});

After

interface Model {
  name: string;
  [others: string]: any;
}
function createModel(x: Model) { ... }

// OK
createModel({name: 'hello', length: 100});

This is a dog or a cat or a horse, not sure yet

interface Animal { move; }
interface Dog extends Animal { woof; }
interface Cat extends Animal { meow; }
interface Horse extends Animal { neigh; }

let x: Animal;
if(...) {
  x = { move: 'doggy paddle', woof: 'bark' };
} else if(...) {
  x = { move: 'catwalk', meow: 'mrar' };
} else {
  x = { move: 'gallop', neigh: 'wilbur' };
}

Two good solutions come to mind here

Specify a closed set for x

// Removes all errors
let x: Dog|Cat|Horse;

or Type assert each thing

// For each initialization
  x = { move: 'doggy paddle', woof: 'bark' } as Dog;

This type is sometimes open and sometimes not

A clean solution to the "data model" problem using intersection types:

interface DataModelOptions {
  name?: string;
  id?: number;
}
interface UserProperties {
  [key: string]: any;
}
function createDataModel(model: DataModelOptions & UserProperties) {
 /* ... */
}
// findDataModel can only look up by name or id
function findDataModel(model: DataModelOptions) {
 /* ... */
}
// OK
createDataModel({name: 'my model', favoriteAnimal: 'cat' });
// Error, 'ID' is not correct (should be 'id')
findDataModel({ ID: 32 });

See also https://github.com/Microsoft/TypeScript/issues/3755

No 'Access-Control-Allow-Origin' header is present on the requested resource - Resteasy

After facing a similar issue, below is what I did :

  • Created a class extending javax.ws.rs.core.Application and added a Cors Filter to it.

To the CORS filter, I added corsFilter.getAllowedOrigins().add("http://localhost:4200");.

Basically, you should add the URL which you want to allow Cross-Origin Resource Sharing. Ans you can also use "*" instead of any specific URL to allow any URL.

public class RestApplication
    extends Application
{
    private Set<Object> singletons = new HashSet<Object>();

    public MessageApplication()
    {
        singletons.add(new CalculatorService()); //CalculatorService is your specific service you want to add/use.
        CorsFilter corsFilter = new CorsFilter();
        // To allow all origins for CORS add following, otherwise add only specific urls.
        // corsFilter.getAllowedOrigins().add("*");
        System.out.println("To only allow restrcited urls ");
        corsFilter.getAllowedOrigins().add("http://localhost:4200");
        singletons = new LinkedHashSet<Object>();
        singletons.add(corsFilter);
    }

    @Override
    public Set<Object> getSingletons()
    {
        return singletons;
    }
}
  • And here is my web.xml:
<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    <display-name>Restful Web Application</display-name>

    <!-- Auto scan rest service -->
    <context-param>
        <param-name>resteasy.scan</param-name>
        <param-value>true</param-value>
    </context-param>

    <context-param>
        <param-name>resteasy.servlet.mapping.prefix</param-name>
        <param-value>/rest</param-value>
    </context-param>

    <listener>
        <listener-class>
            org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap
        </listener-class>
    </listener>

    <servlet>
        <servlet-name>resteasy-servlet</servlet-name>
        <servlet-class>
            org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
        </servlet-class>
        <init-param>
            <param-name>javax.ws.rs.Application</param-name>
            <param-value>com.app.RestApplication</param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>resteasy-servlet</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

</web-app>

The most important code which I was missing when I was getting this issue was, I was not adding my class extending javax.ws.rs.Application i.e RestApplication to the init-param of <servlet-name>resteasy-servlet</servlet-name>

   <init-param>
        <param-name>javax.ws.rs.Application</param-name>
        <param-value>com.app.RestApplication</param-value>
    </init-param>

And therefore my Filter was not able to execute and thus the application was not allowing CORS from the URL specified.

Writing new lines to a text file in PowerShell

You can use the Environment class's static NewLine property to get the proper newline:

$errorMsg =  "{0} Error {1}{2} key {3} expected: {4}{5} local value is: {6}" -f `
               (Get-Date),$keyPath,$value,$key,$policyValue,([Environment]::NewLine),$localValue
Add-Content -Path $logpath $errorMsg

Binary Search Tree - Java Implementation

Here is a sample implementation:

import java.util.*;

public class MyBSTree<K,V> implements MyTree<K,V>{
    private BSTNode<K,V> _root;
    private int _size;
    private Comparator<K> _comparator;
    private int mod = 0;

    public MyBSTree(Comparator<K> comparator){
        _comparator = comparator;
    }

    public Node<K,V> root(){
        return _root;
    }

    public int size(){
        return _size;
    }

    public boolean containsKey(K key){
        if(_root == null){
            return false;
        }

        BSTNode<K,V> node = _root;

        while (node != null){
            int comparison = compare(key, node.key());

            if(comparison == 0){
                return true;
            }else if(comparison <= 0){
                node = node._left;
            }else {
                node = node._right;
            }
        }

        return false;
    }

    private int compare(K k1, K k2){
        if(_comparator != null){
            return _comparator.compare(k1,k2);
        }
        else {
            Comparable<K> comparable = (Comparable<K>)k1;
            return comparable.compareTo(k2);
        }
    }


    public V get(K key){
        Node<K,V> node = node(key);

        return node != null ? node.value() : null;
    }

    private BSTNode<K,V> node(K key){
        if(_root != null){
            BSTNode<K,V> node = _root;

            while (node != null){
                int comparison = compare(key, node.key());

                if(comparison == 0){
                    return node;
                }else if(comparison <= 0){
                    node = node._left;
                }else {
                    node = node._right;
                }
            }
        }

        return null;
    }

    public void add(K key, V value){
        if(key == null){
            throw new IllegalArgumentException("key");
        }

        if(_root == null){
            _root = new BSTNode<K, V>(key, value);
        }

        BSTNode<K,V> prev = null, curr = _root;
        boolean lastChildLeft = false;
        while(curr != null){
            int comparison = compare(key, curr.key());
            prev = curr;

            if(comparison == 0){
                curr._value = value;
                return;
            }else if(comparison < 0){
                curr = curr._left;
                lastChildLeft = true;
            }
            else{
                curr = curr._right;
                lastChildLeft = false;
            }
        }

        mod++;
        if(lastChildLeft){
            prev._left = new BSTNode<K, V>(key, value);
        }else {
            prev._right = new BSTNode<K, V>(key, value);
        }
    }

    private void removeNode(BSTNode<K,V> curr){
        if(curr.left() == null && curr.right() == null){
            if(curr == _root){
                _root = null;
            }else{
                if(curr.isLeft()) curr._parent._left = null;
                else curr._parent._right = null;
            }
        }
        else if(curr._left == null && curr._right != null){
            curr._key = curr._right._key;
            curr._value = curr._right._value;
            curr._left = curr._right._left;
            curr._right = curr._right._right;
        }
        else if(curr._left != null && curr._right == null){
            curr._key = curr._left._key;
            curr._value = curr._left._value;
            curr._right = curr._left._right;
            curr._left = curr._left._left;
        }
        else { // both left & right exist
            BSTNode<K,V> x = curr._left;
            // find right-most node of left sub-tree
            while (x._right != null){ 
                x = x._right;
            }
            // move that to current
            curr._key = x._key;
            curr._value = x._value;
            // delete duplicate data
            removeNode(x);
        }
    }


    public V remove(K key){
        BSTNode<K,V> curr = _root;
        V val = null;
        while(curr != null){
            int comparison = compare(key, curr.key());
            if(comparison == 0){
                val = curr._value;
                removeNode(curr);
                mod++;
                break;
            }else if(comparison < 0){
                curr = curr._left;
            }
            else{
                curr = curr._right;
            }
        }

        return val;
    }

    public Iterator<MyTree.Node<K,V>> iterator(){
        return new MyIterator();
    }

    private class MyIterator implements Iterator<Node<K,V>>{
        int _startMod;
        Stack<BSTNode<K,V>> _stack;

        public MyIterator(){
            _startMod = MyBSTree.this.mod;
            _stack = new Stack<BSTNode<K, V>>();

            BSTNode<K,V> node = MyBSTree.this._root;
            while (node != null){
                _stack.push(node);
                node = node._left;
            }
        }

        public void remove(){
            throw new UnsupportedOperationException();
        }

        public boolean hasNext(){
            if(MyBSTree.this.mod != _startMod){
                throw new ConcurrentModificationException();
            }

            return !_stack.empty();
        }

        public Node<K,V> next(){
            if(MyBSTree.this.mod != _startMod){
                throw new ConcurrentModificationException();
            }

            if(!hasNext()){
                throw new NoSuchElementException();
            }

            BSTNode<K,V> node = _stack.pop();
            BSTNode<K,V> x = node._right;
            while (x != null){
                _stack.push(x);
                x = x._left;
            }

            return node;
        }
    }

    @Override
    public String toString(){
        if(_root == null) return "[]";

        return _root.toString();
    }

    private static class BSTNode<K,V> implements Node<K,V>{
        K _key;
        V _value;
        BSTNode<K,V> _left, _right, _parent;

        public BSTNode(K key, V value){
            if(key == null){
                throw new IllegalArgumentException("key");
            }

            _key = key;
            _value = value;
        }

        public K key(){
            return _key;
        }

        public V value(){
            return _value;
        }

        public Node<K,V> left(){
            return _left;
        }

        public Node<K,V> right(){
            return _right;
        }

        public Node<K,V> parent(){
            return _parent;
        }

        boolean isLeft(){
            if(_parent == null) return false;

            return _parent._left == this;
        }

        boolean isRight(){
            if(_parent == null) return false;

            return _parent._right == this;
        }

        @Override
        public boolean equals(Object o){
            if(o == null){
                return false;
            }

            try{
                BSTNode<K,V> node = (BSTNode<K,V>)o;
                return node._key.equals(_key) && ((_value == null && node._value == null) || (_value != null && _value.equals(node._value)));
            }catch (ClassCastException ex){
                return false;
            }
        }

        @Override
        public int hashCode(){
            int hashCode = _key.hashCode();

            if(_value != null){
                hashCode ^= _value.hashCode();
            }

            return hashCode;
        }

        @Override
        public String toString(){
            String leftStr = _left != null ? _left.toString() : "";
            String rightStr = _right != null ? _right.toString() : "";
            return "["+leftStr+" "+_key+" "+rightStr+"]";
        }
    }
}

Conda: Installing / upgrading directly from github

conda doesn't support this directly because it installs from binaries, whereas git install would be from source. conda build does support recipes that are built from git. On the other hand, if all you want to do is keep up-to-date with the latest and greatest of a package, using pip inside of Anaconda is just fine, or alternately, use setup.py develop against a git clone.

SQL Server: how to create a stored procedure

try this:

create procedure dept_count( @dept_name varchar(20), @d_count INTEGER out)

   AS
   begin
     select count(*) into d_count
     from instructor
     where instructor.dept_name=dept_count.dept_name
   end

Connection refused on docker container

In Windows, you also normally need to run command line as administrator.

As standard-user:

docker build -t myimage -f Dockerfile .
Sending build context to Docker daemon  106.8MB
Step 1/1 : FROM mcr.microsoft.com/dotnet/core/runtime:3.0
Get https://mcr.microsoft.com/v2/: dial tcp: lookup mcr.microsoft.com on [::1]:53: read udp [::1]:45540->[::1]:53: read: 
>>>connection refused

But as an administrator.

docker build -t myimage -f Dockerfile .
Sending build context to Docker daemon  106.8MB
Step 1/1 : FROM mcr.microsoft.com/dotnet/core/runtime:3.0
3.0: Pulling from dotnet/core/runtime
68ced04f60ab: Pull complete                                                                                             e936bd534ffb: Pull complete                                                                                             caf64655bcbb: Pull complete                                                                                             d1927dbcbcab: Pull complete                                                                                             Digest: sha256:e0c67764f530a9cad29a09816614c0129af8fe3bd550eeb4e44cdaddf8f5aa40
Status: Downloaded newer image for mcr.microsoft.com/dotnet/core/runtime:3.0
 ---> f059cd71a22a
Successfully built f059cd71a22a
Successfully tagged myimage:latest

Remove leading comma from a string

To remove the first character you would use:

var myOriginalString = ",'first string','more','even more'"; 
var myString = myOriginalString.substring(1);

I'm not sure this will be the result you're looking for though because you will still need to split it to create an array with it. Maybe something like:

var myString = myOriginalString.substring(1);
var myArray = myString.split(',');

Keep in mind, the ' character will be a part of each string in the split here.

AppFabric installation failed because installer MSI returned with error code : 1603

I also hit this error…

The installation msi will try to create a new task in the Windows Task scheduler to remind you to give customer feedback. This install step executes regardless of whether you do or do not click the check box to participate in customer feedback. In many corporate environments (including mine) creating new windows tasks is denied to all but domain administrators. As a result, running as a local admin is not sufficient and the entire installation fails when adding the task returns “access denied”. This shows up in the install log as a 1603.

The only workaround we could find was to manually pull all the files out of the msi, remove the “add schedule task” from the install script, and then create a new msi. After that one line change, it worked fine.

Error:Execution failed for task ':app:compileDebugKotlin'. > Compilation error. See log for more details

Below changes worked for me

I change distribution URL, located in gradle-wrapper.properties

distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zip

And

dependencies {
    classpath 'com.android.tools.build:gradle:3.2.1'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
  }

kotlin version 1.2.71

Calling Non-Static Method In Static Method In Java

It sounds like the method really should be static (i.e. it doesn't access any data members and it doesn't need an instance to be invoked on). Since you used the term "static class", I understand that the whole class is probably dedicated to utility-like methods that could be static.

However, Java doesn't allow the implementation of an interface-defined method to be static. So when you (naturally) try to make the method static, you get the "cannot-hide-the-instance-method" error. (The Java Language Specification mentions this in section 9.4: "Note that a method declared in an interface must not be declared static, or a compile-time error occurs, because static methods cannot be abstract.")

So as long as the method is present in xInterface, and your class implements xInterface, you won't be able to make the method static.

If you can't change the interface (or don't want to), there are several things you can do:

  • Make the class a singleton: make the constructor private, and have a static data member in the class to hold the only existing instance. This way you'll be invoking the method on an instance, but at least you won't be creating new instances each time you need to call the method.
  • Implement 2 methods in your class: an instance method (as defined in xInterface), and a static method. The instance method will consist of a single line that delegates to the static method.

org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]A child container failed during start

If you are not using annotation based Servlet then please remove annotation @WebServlet("/YourServletName") from the starting of the servlet. This annotation confuses the mapping with web.xml, after removing this annotation Tomcat server will work properly.

"detached entity passed to persist error" with JPA/EJB code

I know its kind of too late and proly every one got the answer. But little bit more to add to this: when GenerateType is set, persist() on an object is expected to get an id generated.

If there is a value set to the Id by user already, hibernate treats it as saved record and so it is treated as detached.

if the id is null - in this situation a null pointer exception is raised when the type is AUTO or IDENTITY etc unless the id is generated from a table or a sequece etc.

design: this happens when the table has a bean property as primary key. GenerateType must be set only when an id is autogenerated. remove this and the insert should work with the user specified id. (it is a bad design to have a property mapped to primary key field)

How do I install SciPy on 64 bit Windows?

As the transcript for SciPy told you, SciPy isn't really supposed to work on Win64:

Warning: Windows 64 bits support is experimental, and only available for
testing. You are advised not to use it for production.

So I would suggest to install the 32-bit version of Python, and stop attempting to build SciPy yourself. If you still want to try anyway, you first need to compile BLAS and LAPACK, as PiotrLegnica says. See the transcript for the places where it was looking for compiled versions of these libraries.

What is the usefulness of PUT and DELETE HTTP request methods?

Although I take the risk of not being popular I say they are not useful nowadays.

I think they were well intended and useful in the past when for example DELETE told the server to delete the resource found at supplied URL and PUT (with its sibling PATCH) told the server to do update in an idempotent manner.

Things evolved and URLs became virtual (see url rewriting for example) making resources lose their initial meaning of real folder/subforder/file and so, CRUD action verbs covered by HTTP protocol methods (GET, POST, PUT/PATCH, DELETE) lost track.

Let's take an example:

  • /api/entity/list/{id} vs GET /api/entity/{id}
  • /api/entity/add/{id} vs POST /api/entity
  • /api/entity/edit/{id} vs PUT /api/entity/{id}
  • /api/entity/delete/{id} vs DELETE /api/entity/{id}

On the left side is not written the HTTP method, essentially it doesn't matter (POST and GET are enough) and on the right side appropriate HTTP methods are used.

Right side looks elegant, clean and professional. Imagine now you have to maintain a code that's been using the elegant API and you have to search where deletion call is done. You'll search for "api/entity" and among results you'll have to see which one is doing DELETE. Or even worse, you have a junior programmer which by mistake switched PUT with DELETE and as URL is the same shit happened.

In my opinion putting the action verb in the URL has advantages over using the appropriate HTTP method for that action even if it's not so elegant. If you want to see where delete call is made you just have to search for "api/entity/delete" and you'll find it straight away.

Building an API without the whole HTTP array of methods makes it easier to be consumed and maintained afterwards

How to save/restore serializable object to/from file?

I just wrote a blog post on saving an object's data to Binary, XML, or Json. You are correct that you must decorate your classes with the [Serializable] attribute, but only if you are using Binary serialization. You may prefer to use XML or Json serialization. Here are the functions to do it in the various formats. See my blog post for more details.

Binary

/// <summary>
/// Writes the given object instance to a binary file.
/// <para>Object type (and all child types) must be decorated with the [Serializable] attribute.</para>
/// <para>To prevent a variable from being serialized, decorate it with the [NonSerialized] attribute; cannot be applied to properties.</para>
/// </summary>
/// <typeparam name="T">The type of object being written to the binary file.</typeparam>
/// <param name="filePath">The file path to write the object instance to.</param>
/// <param name="objectToWrite">The object instance to write to the binary file.</param>
/// <param name="append">If false the file will be overwritten if it already exists. If true the contents will be appended to the file.</param>
public static void WriteToBinaryFile<T>(string filePath, T objectToWrite, bool append = false)
{
    using (Stream stream = File.Open(filePath, append ? FileMode.Append : FileMode.Create))
    {
        var binaryFormatter = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
        binaryFormatter.Serialize(stream, objectToWrite);
    }
}

/// <summary>
/// Reads an object instance from a binary file.
/// </summary>
/// <typeparam name="T">The type of object to read from the binary file.</typeparam>
/// <param name="filePath">The file path to read the object instance from.</param>
/// <returns>Returns a new instance of the object read from the binary file.</returns>
public static T ReadFromBinaryFile<T>(string filePath)
{
    using (Stream stream = File.Open(filePath, FileMode.Open))
    {
        var binaryFormatter = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
        return (T)binaryFormatter.Deserialize(stream);
    }
}

XML

Requires the System.Xml assembly to be included in your project.

/// <summary>
/// Writes the given object instance to an XML file.
/// <para>Only Public properties and variables will be written to the file. These can be any type though, even other classes.</para>
/// <para>If there are public properties/variables that you do not want written to the file, decorate them with the [XmlIgnore] attribute.</para>
/// <para>Object type must have a parameterless constructor.</para>
/// </summary>
/// <typeparam name="T">The type of object being written to the file.</typeparam>
/// <param name="filePath">The file path to write the object instance to.</param>
/// <param name="objectToWrite">The object instance to write to the file.</param>
/// <param name="append">If false the file will be overwritten if it already exists. If true the contents will be appended to the file.</param>
public static void WriteToXmlFile<T>(string filePath, T objectToWrite, bool append = false) where T : new()
{
    TextWriter writer = null;
    try
    {
        var serializer = new XmlSerializer(typeof(T));
        writer = new StreamWriter(filePath, append);
        serializer.Serialize(writer, objectToWrite);
    }
    finally
    {
        if (writer != null)
            writer.Close();
    }
}

/// <summary>
/// Reads an object instance from an XML file.
/// <para>Object type must have a parameterless constructor.</para>
/// </summary>
/// <typeparam name="T">The type of object to read from the file.</typeparam>
/// <param name="filePath">The file path to read the object instance from.</param>
/// <returns>Returns a new instance of the object read from the XML file.</returns>
public static T ReadFromXmlFile<T>(string filePath) where T : new()
{
    TextReader reader = null;
    try
    {
        var serializer = new XmlSerializer(typeof(T));
        reader = new StreamReader(filePath);
        return (T)serializer.Deserialize(reader);
    }
    finally
    {
        if (reader != null)
            reader.Close();
    }
}

Json

You must include a reference to Newtonsoft.Json assembly, which can be obtained from the Json.NET NuGet Package.

/// <summary>
/// Writes the given object instance to a Json file.
/// <para>Object type must have a parameterless constructor.</para>
/// <para>Only Public properties and variables will be written to the file. These can be any type though, even other classes.</para>
/// <para>If there are public properties/variables that you do not want written to the file, decorate them with the [JsonIgnore] attribute.</para>
/// </summary>
/// <typeparam name="T">The type of object being written to the file.</typeparam>
/// <param name="filePath">The file path to write the object instance to.</param>
/// <param name="objectToWrite">The object instance to write to the file.</param>
/// <param name="append">If false the file will be overwritten if it already exists. If true the contents will be appended to the file.</param>
public static void WriteToJsonFile<T>(string filePath, T objectToWrite, bool append = false) where T : new()
{
    TextWriter writer = null;
    try
    {
        var contentsToWriteToFile = JsonConvert.SerializeObject(objectToWrite);
        writer = new StreamWriter(filePath, append);
        writer.Write(contentsToWriteToFile);
    }
    finally
    {
        if (writer != null)
            writer.Close();
    }
}

/// <summary>
/// Reads an object instance from an Json file.
/// <para>Object type must have a parameterless constructor.</para>
/// </summary>
/// <typeparam name="T">The type of object to read from the file.</typeparam>
/// <param name="filePath">The file path to read the object instance from.</param>
/// <returns>Returns a new instance of the object read from the Json file.</returns>
public static T ReadFromJsonFile<T>(string filePath) where T : new()
{
    TextReader reader = null;
    try
    {
        reader = new StreamReader(filePath);
        var fileContents = reader.ReadToEnd();
        return JsonConvert.DeserializeObject<T>(fileContents);
    }
    finally
    {
        if (reader != null)
            reader.Close();
    }
}

Example

// Write the contents of the variable someClass to a file.
WriteToBinaryFile<SomeClass>("C:\someClass.txt", object1);

// Read the file contents back into a variable.
SomeClass object1= ReadFromBinaryFile<SomeClass>("C:\someClass.txt");

What does git rev-parse do?

Just to elaborate on the etymology of the command name rev-parse, Git consistently uses the term rev in plumbing commands as short for "revision" and generally meaning the 40-character SHA1 hash for a commit. The command rev-list for example prints a list of 40-char commit hashes for a branch or whatever.

In this case the name might be expanded to parse-a-commitish-to-a-full-SHA1-hash. While the command has the several ancillary functions mentioned in Tuxdude's answer, its namesake appears to be the use case of transforming a user-friendly reference like a branch name or abbreviated hash into the unambiguous 40-character SHA1 hash most useful for many programming/plumbing purposes.

I know I was thinking it was "reverse-parse" something for quite a while before I figured it out and had the same trouble making sense of the terms "massaging" and "manipulation" :)

Anyway, I find this "parse-to-a-revision" notion a satisfying way to think of it, and a reliable concept for bringing this command to mind when I need that sort of thing. Frequently in scripting Git you take a user-friendly commit reference as user input and generally want to get it resolved to a validated and unambiguous working reference as soon after receiving it as possible. Otherwise input translation and validation tends to proliferate through the script.

NewtonSoft.Json Serialize and Deserialize class with property of type IEnumerable<ISomeInterface>

You don't need to use JsonConverterAttribute, keep your model clean, also use CustomCreationConverter, the code is simpler:

public class SampleConverter : CustomCreationConverter<ISample>
{
    public override ISample Create(Type objectType)
    {
        return new Sample();
    }
}

Then:

var sz = JsonConvert.SerializeObject( sampleGroupInstance );
JsonConvert.DeserializeObject<SampleGroup>( sz, new SampleConverter());

Documentation: Deserialize with CustomCreationConverter

Class extending more than one class Java?

Hello please note like real work.

Children can not have two mother

So in java, subclass can not have two parent class.

MVC Return Partial View as JSON

You can extract the html string from the PartialViewResult object, similar to the answer to this thread:

Render a view as a string

PartialViewResult and ViewResult both derive from ViewResultBase, so the same method should work on both.

Using the code from the thread above, you would be able to use:

public ActionResult ReturnSpecialJsonIfInvalid(AwesomenessModel model)
{
    if (ModelState.IsValid)
    {
        if(Request.IsAjaxRequest())
            return PartialView("NotEvil", model);
        return View(model)
    }
    if(Request.IsAjaxRequest())
    {
        return Json(new { error = true, message = RenderViewToString(PartialView("Evil", model))});
    }
    return View(model);
}

A terminal command for a rooted Android to remount /System as read/write

You can run the mount command without parameter in order to get partition information before constructing your mount command. Here is an example of the mount command without parameter outputed from my HTC Hero.

$ mount
mount
rootfs / rootfs ro 0 0
tmpfs /dev tmpfs rw,mode=755 0 0
devpts /dev/pts devpts rw,mode=600 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
tmpfs /sqlite_stmt_journals tmpfs rw,size=4096k 0 0
none /dev/cpuctl cgroup rw,cpu 0 0
/dev/block/mtdblock3 /system yaffs2 rw 0 0
/dev/block/mtdblock5 /data yaffs2 rw,nosuid,nodev 0 0
/dev/block/mtdblock4 /cache yaffs2 rw,nosuid,nodev 0 0
/dev/block//vold/179:1 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=
1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,s
hortname=mixed,utf8,errors=remount-ro 0 0

Cannot simply use PostgreSQL table name ("relation does not exist")

From what I've read, this error means that you're not referencing the table name correctly. One common reason is that the table is defined with a mixed-case spelling, and you're trying to query it with all lower-case.

In other words, the following fails:

CREATE TABLE "SF_Bands" ( ... );

SELECT * FROM sf_bands;  -- ERROR!

Use double-quotes to delimit identifiers so you can use the specific mixed-case spelling as the table is defined.

SELECT * FROM "SF_Bands";

Re your comment, you can add a schema to the "search_path" so that when you reference a table name without qualifying its schema, the query will match that table name by checked each schema in order. Just like PATH in the shell or include_path in PHP, etc. You can check your current schema search path:

SHOW search_path
  "$user",public

You can change your schema search path:

SET search_path TO showfinder,public;

See also http://www.postgresql.org/docs/8.3/static/ddl-schemas.html

How to remove element from ArrayList by checking its value?

Use a iterator to loop through list and then delete the required object.

    Iterator itr = a.iterator();
    while(itr.hasNext()){
        if(itr.next().equals("acbd"))
            itr.remove();
    }

Create zip file and ignore directory structure

Use the -j option:

   -j     Store  just the name of a saved file (junk the path), and do not
          store directory names. By default, zip will store the full  path
          (relative to the current path).

Setting UILabel text to bold

Use font property of UILabel:

label.font = UIFont(name:"HelveticaNeue-Bold", size: 16.0)

or use default system font to bold text:

label.font = UIFont.boldSystemFont(ofSize: 16.0)

Vertically align text next to an image?

Not sure as to why it doesn't render it on your navigation's browser, but I normally use an snippet like this when trying to display a header with an image and a centered text, hope it helps!

https://output.jsbin.com/jeqorahupo

            <hgroup style="display:block; text-align:center;  vertical-align:middle;  margin:inherit auto; padding:inherit auto; max-height:inherit">

            <header style="background:url('http://lorempixel.com/30/30/') center center no-repeat; background-size:auto; display:inner-block; vertical-align:middle; position:relative; position:absolute; top:inherit; left:inherit; display: -webkit-box; display: -webkit-flex;display: -moz-box;display: -ms-flexbox;display: flex;-webkit-flex-align: center;-ms-flex-align: center;-webkit-align-items: center;align-items: center;">

            <image src="http://lorempixel.com/60/60/" title="Img title" style="opacity:0.35"></img>
                    http://lipsum.org</header>
                    </hgroup>

MongoDB: Server has startup warnings ''Access control is not enabled for the database''

You need to delete your old db folder and recreate new one. It will resolve your issue.

Creating a folder if it does not exists - "Item already exists"

With New-Item you can add the Force parameter

New-Item -Force -ItemType directory -Path foo

Or the ErrorAction parameter

New-Item -ErrorAction Ignore -ItemType directory -Path foo

jQuery events .load(), .ready(), .unload()

window load will wait for all resources to be loaded.

document ready waits for the document to be initialized.

unload well, waits till the document is being unloaded.

the order is: document ready, window load, ... ... ... ... window unload.

always use document ready unless you need to wait for your images to load.

shorthand for document ready:

$(function(){
    // yay!
});

Download File Using Javascript/jQuery

let args = {"data":htmlData,"filename":exampleName}

To create a HTMl file and download

window.downloadHTML = function(args) {
var data, filename, link;
var csv = args.data;
if (csv == null) return;
filename = args.filename || 'report.html';
data = 'data:text/html;charset=utf-8,' + encodeURIComponent(csv);
console.log(data);
link = document.createElement('a');
link.setAttribute('href', data);
link.setAttribute('download', filename);
document.body.appendChild(link);
link.click();
document.body.removeChild(link);}

To create and download a CSV

window.downloadCSV = function(args) {
var data, filename, link;
var csv = args.data;
if (csv == null) return;
filename = args.filename || 'report.csv';
if (!csv.match(/^data:text\/csv/i)) {
    csv = 'data:text/csv;charset=utf-8,' + csv;
}
data = encodeURI(csv);
link = document.createElement('a');
link.setAttribute('href', data);
link.setAttribute('download', filename);
document.body.appendChild(link);
link.click();
document.body.removeChild(link);

}

Date query with ISODate in mongodb doesn't seem to work

This worked for me while searching for value less than or equal than now:

db.collectionName.find({ "dt": { "$lte" : new Date() + "" } });

HTTP GET request in JavaScript?

Prototype makes it dead simple

new Ajax.Request( '/myurl', {
  method:  'get',
  parameters:  { 'param1': 'value1'},
  onSuccess:  function(response){
    alert(response.responseText);
  },
  onFailure:  function(){
    alert('ERROR');
  }
});

Can iterators be reset in Python?

I see many answers suggesting itertools.tee, but that's ignoring one crucial warning in the docs for it:

This itertool may require significant auxiliary storage (depending on how much temporary data needs to be stored). In general, if one iterator uses most or all of the data before another iterator starts, it is faster to use list() instead of tee().

Basically, tee is designed for those situation where two (or more) clones of one iterator, while "getting out of sync" with each other, don't do so by much -- rather, they say in the same "vicinity" (a few items behind or ahead of each other). Not suitable for the OP's problem of "redo from the start".

L = list(DictReader(...)) on the other hand is perfectly suitable, as long as the list of dicts can fit comfortably in memory. A new "iterator from the start" (very lightweight and low-overhead) can be made at any time with iter(L), and used in part or in whole without affecting new or existing ones; other access patterns are also easily available.

As several answers rightly remarked, in the specific case of csv you can also .seek(0) the underlying file object (a rather special case). I'm not sure that's documented and guaranteed, though it does currently work; it would probably be worth considering only for truly huge csv files, in which the list I recommmend as the general approach would have too large a memory footprint.

Full examples of using pySerial package

http://web.archive.org/web/20131107050923/http://www.roman10.net/serial-port-communication-in-python/comment-page-1/

#!/usr/bin/python

import serial, time
#initialization and open the port

#possible timeout values:
#    1. None: wait forever, block call
#    2. 0: non-blocking mode, return immediately
#    3. x, x is bigger than 0, float allowed, timeout block call

ser = serial.Serial()
#ser.port = "/dev/ttyUSB0"
ser.port = "/dev/ttyUSB7"
#ser.port = "/dev/ttyS2"
ser.baudrate = 9600
ser.bytesize = serial.EIGHTBITS #number of bits per bytes
ser.parity = serial.PARITY_NONE #set parity check: no parity
ser.stopbits = serial.STOPBITS_ONE #number of stop bits
#ser.timeout = None          #block read
ser.timeout = 1            #non-block read
#ser.timeout = 2              #timeout block read
ser.xonxoff = False     #disable software flow control
ser.rtscts = False     #disable hardware (RTS/CTS) flow control
ser.dsrdtr = False       #disable hardware (DSR/DTR) flow control
ser.writeTimeout = 2     #timeout for write

try: 
    ser.open()
except Exception, e:
    print "error open serial port: " + str(e)
    exit()

if ser.isOpen():

    try:
        ser.flushInput() #flush input buffer, discarding all its contents
        ser.flushOutput()#flush output buffer, aborting current output 
                 #and discard all that is in buffer

        #write data
        ser.write("AT+CSQ")
        print("write data: AT+CSQ")

       time.sleep(0.5)  #give the serial port sometime to receive the data

       numOfLines = 0

       while True:
          response = ser.readline()
          print("read data: " + response)

        numOfLines = numOfLines + 1

        if (numOfLines >= 5):
            break

        ser.close()
    except Exception, e1:
        print "error communicating...: " + str(e1)

else:
    print "cannot open serial port "

JSLint is suddenly reporting: Use the function form of "use strict"

Add a file .jslintrc (or .jshintrc in the case of jshint) at the root of your project with the following content:

{
    "node": true
}

Eclipse doesn't stop at breakpoints

Try to restart eclipse, that works sometimes. I guess there is some kind of cache there.

Is it better to use std::memcpy() or std::copy() in terms to performance?

In theory, memcpy might have a slight, imperceptible, infinitesimal, performance advantage, only because it doesn't have the same requirements as std::copy. From the man page of memcpy:

To avoid overflows, the size of the arrays pointed by both the destination and source parameters, shall be at least num bytes, and should not overlap (for overlapping memory blocks, memmove is a safer approach).

In other words, memcpy can ignore the possibility of overlapping data. (Passing overlapping arrays to memcpy is undefined behavior.) So memcpy doesn't need to explicitly check for this condition, whereas std::copy can be used as long as the OutputIterator parameter is not in the source range. Note this is not the same as saying that the source range and destination range can't overlap.

So since std::copy has somewhat different requirements, in theory it should be slightly (with an extreme emphasis on slightly) slower, since it probably will check for overlapping C-arrays, or else delegate the copying of C-arrays to memmove, which needs to perform the check. But in practice, you (and most profilers) probably won't even detect any difference.

Of course, if you're not working with PODs, you can't use memcpy anyway.

How do I resolve this "ORA-01109: database not open" error?

If you are using 19c then just follow the following steps

  1. Login with sys user.
  2. alter the session to the pluggable database with the following command.
  3. SQL>alter session set container=orclpdb;
  4. Next startup the database.
  5. SQL>startup After that database will not show the above error.

Undefined reference to pthread_create in Linux

If you are using cmake, you can use:

add_compile_options(-pthread)

Or

SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pthread")

Custom seekbar (thumb size, color and background)

android:minHeight android:maxHeight is important for that.

<SeekBar
    android:id="@+id/pb"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:maxHeight="2dp"
    android:minHeight="2dp"
    android:progressDrawable="@drawable/seekbar_bg"
    android:thumb="@drawable/seekbar_thumb"
    android:max="100"
    android:progress="50"/>

seekbar_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list
    xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@android:id/background">
        <shape>
            <corners android:radius="3dp" />
            <solid android:color="#ECF0F1" />
        </shape>
    </item>
    <item android:id="@android:id/secondaryProgress">
        <clip>
            <shape>
                <corners android:radius="3dp" />
                <solid android:color="#C6CACE" />
            </shape>
        </clip>
    </item>
    <item android:id="@android:id/progress">
        <clip>
            <shape>
                <corners android:radius="3dp" />
                <solid android:color="#16BC5C" />
            </shape>
        </clip>
    </item>
</layer-list>

seekbar_thumb.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <solid android:color="#16BC5C" />
    <stroke
        android:width="1dp"
        android:color="#16BC5C" />
    <size
        android:height="20dp"
        android:width="20dp" />
</shape>

Generate an integer that is not among four billion given ones

If there is no size limit, the quickest way is to take the length of the file, and generate the length of the file+1 number of random digits (or just "11111..." s). Advantage: you don't even need to read the file, and you can minimize memory use nearly to zero. Disadvantage: You will print billions of digits.

However, if the only factor was minimizing memory usage, and nothing else is important, this would be the optimal solution. It might even get you a "worst abuse of the rules" award.

How to convert a byte to its binary string representation

Get each bit of byte and convert to string. Say byte has 8 bits, and we can get them one by one via bit move. For example, we move the second bit of the byte 6 bits to right, the second bit at last of bit of 8 bits, then and(&) with 0x0001 to clean the front bits.

public static String getByteBinaryString(byte b) {
    StringBuilder sb = new StringBuilder();
    for (int i = 7; i >= 0; --i) {
        sb.append(b >>> i & 1);
    }
    return sb.toString();
}

How to get first 5 characters from string

You can get your result by simply use substr():

Syntax substr(string,start,length)

Example

<?php
$myStr = "HelloWordl";
echo substr($myStr,0,5);
?>

Output :

 Hello

tsc throws `TS2307: Cannot find module` for a local file

In VS2019, the project property page, TypeScript Build tab has a setting (dropdown) for "Module System". When I changed that from "ES2015" to CommonJS, then VS2019 IDE stopped complaining that it could find neither axios nor redux-thunk (TS2307).

tsconfig.json:

{
  "compilerOptions": {
    "allowJs": true,
    "baseUrl": "src",
    "forceConsistentCasingInFileNames": true,
    "jsx": "react",
    "lib": [
      "es6",
      "dom",
      "es2015.promise"
    ],
    "module": "esnext",
    "moduleResolution": "node",
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noUnusedLocals": true,
    "outDir": "build/dist",
    "rootDir": "src",
    "sourceMap": true,
    "strictNullChecks": true,
    "suppressImplicitAnyIndexErrors": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "target": "es5",
    "skipLibCheck": true,
    "strict": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true
  },
  "exclude": [
    "build",
    "scripts",
    "acceptance-tests",
    "webpack",
    "jest",
    "src/setupTests.ts",
    "node_modules",
    "obj",
    "**/*.spec.ts"
  ],
  "include": [
    "src",
    "src/**/*.ts",
    "@types/**/*.d.ts",
    "node_modules/axios",
    "node_modules/redux-thunk"
  ]
}

Grant execute permission for a user on all stored procedures in database?

use below code , change proper database name and user name and then take that output and execute in SSMS. FOR SQL 2005 ABOVE

USE <database_name> 
select 'GRANT EXECUTE ON ['+name+'] TO [userName]  '  
from sys.objects  
where type ='P' 
and is_ms_shipped = 0  

How to get your Netbeans project into Eclipse

One other easy way of doing it would be as follows (if you have a simple NetBeans project and not using maven for example).

  1. In Eclipse, Go to File -> New -> Java Project
  2. Give a name for your project and click finish to create your project
  3. When the project is created find the source folder in NetBeans project, drag and drop all the source files from the NetBeans project to 'src' folder of your new created project in eclipse.
  4. Move the java source files to respective package (if required)
  5. Now you should be able to run your NetBeans project in Eclipse.

Is there a default password to connect to vagrant when using `homestead ssh` for the first time?

This is the default working setup https://www.youtube.com/watch?v=XiD7JTCBdpI

Use Connection Method: standard TCP/IP over ssh

Then ssh hostname: 127.0.0.1:2222

SSH Username: vagrant password vagrant

MySQL Hostname: localhost

Username: homestead password:secret

Laravel Rule Validation for Numbers

$this->validate($request,[
        'input_field_name'=>'digits_between:2,5',
       ]);

Try this it will be work

Mockito : how to verify method was called on an object created within a method?

Solution for your example code using PowerMockito.whenNew

  • mockito-all 1.10.8
  • powermock-core 1.6.1
  • powermock-module-junit4 1.6.1
  • powermock-api-mockito 1.6.1
  • junit 4.12

FooTest.java

package foo;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

//Both @PrepareForTest and @RunWith are needed for `whenNew` to work 
@RunWith(PowerMockRunner.class)
@PrepareForTest({ Foo.class })
public class FooTest {

    // Class Under Test
    Foo cut;

    @Mock
    Bar barMock;

    @Before
    public void setUp() throws Exception {
        cut = new Foo();

    }

    @After
    public void tearDown() {
        cut = null;

    }

    @Test
    public void testFoo() throws Exception {

        // Setup
        PowerMockito.whenNew(Bar.class).withNoArguments()
                .thenReturn(this.barMock);

        // Test
        cut.foo();

        // Validations
        Mockito.verify(this.barMock, Mockito.times(1)).someMethod();

    }

}

JUnit Output JUnit Output

How to stop an animation (cancel() does not work)

You must use .clearAnimation(); method in UI thread:

runOnUiThread(new Runnable() {
    @Override
    public void run() {
        v.clearAnimation();
    }
});

JavaScript DOM remove element

In most browsers, there's a slightly more succinct way of removing an element from the DOM than calling .removeChild(element) on its parent, which is to just call element.remove(). In due course, this will probably become the standard and idiomatic way of removing an element from the DOM.

The .remove() method was added to the DOM Living Standard in 2011 (commit), and has since been implemented by Chrome, Firefox, Safari, Opera, and Edge. It was not supported in any version of Internet Explorer.

If you want to support older browsers, you'll need to shim it. This turns out to be a little irritating, both because nobody seems to have made a all-purpose DOM shim that contains these methods, and because we're not just adding the method to a single prototype; it's a method of ChildNode, which is just an interface defined by the spec and isn't accessible to JavaScript, so we can't add anything to its prototype. So we need to find all the prototypes that inherit from ChildNode and are actually defined in the browser, and add .remove to them.

Here's the shim I came up with, which I've confirmed works in IE 8.

(function () {
    var typesToPatch = ['DocumentType', 'Element', 'CharacterData'],
        remove = function () {
            // The check here seems pointless, since we're not adding this
            // method to the prototypes of any any elements that CAN be the
            // root of the DOM. However, it's required by spec (see point 1 of
            // https://dom.spec.whatwg.org/#dom-childnode-remove) and would
            // theoretically make a difference if somebody .apply()ed this
            // method to the DOM's root node, so let's roll with it.
            if (this.parentNode != null) {
                this.parentNode.removeChild(this);
            }
        };

    for (var i=0; i<typesToPatch.length; i++) {
        var type = typesToPatch[i];
        if (window[type] && !window[type].prototype.remove) {
            window[type].prototype.remove = remove;
        }
    }
})();

This won't work in IE 7 or lower, since extending DOM prototypes isn't possible before IE 8. I figure, though, that on the verge of 2015 most people needn't care about such things.

Once you've included them shim, you'll be able to remove a DOM element element from the DOM by simply calling

element.remove();

Create list of object from another using Java 8 Streams

I prefer to solve this in the classic way, creating a new array of my desired data type:

List<MyNewType> newArray = new ArrayList<>();
myOldArray.forEach(info -> newArray.add(objectMapper.convertValue(info, MyNewType.class)));

Getting the screen resolution using PHP

I don't think you can detect the screen size purely with PHP but you can detect the user-agent..

<?php
    if ( stristr($ua, "Mobile" )) {
        $DEVICE_TYPE="MOBILE";
    }

    if (isset($DEVICE_TYPE) and $DEVICE_TYPE=="MOBILE") {
        echo '<link rel="stylesheet" href="/css/mobile.css" />'
    }
?>

Here's a link to a more detailed script: PHP Mobile Detect

How do I give ASP.NET permission to write to a folder in Windows 7?

Giving write permissions to all IIS_USRS group is a bad idea from the security point of view. You dont need to do that and you can go with giving permissions only to system user running the application pool.

If you are using II7 (and I guess you do) do the following.

  1. Open IIS7
  2. Select Website for which you need to modify permissions
  3. Go to Basic Settings and see which application pool you're using.
  4. Go to Application pools and find application pool from #3
  5. Find system account used for running this application pool (Identity column)
  6. Navigate to your storage folder in IIS, select it and click on Edit Permissions (under Actions sub menu on the right)
  7. Open security tab and add needed permissions only for user you identified in #3

Note #1: if you see ApplicationPoolIdentity in #3 you need to reference this system user like this IIS AppPool{application_pool_name} . For example IIS AppPool\DefaultAppPool

Note #2: when adding this user make sure to set correct locations in the Select Users or Groups dialog. This needs to be set to local machine because this is local account.

SQL Insert Multiple Rows

We will import the CSV file into the destination table in the simplest form. I placed my sample CSV file on the C: drive and now we will create a table which we will import data from the CSV file.

DROP TABLE IF EXISTS Sales 

CREATE TABLE [dbo].[Sales](
    [Region] [varchar](50) ,
    [Country] [varchar](50) ,
    [ItemType] [varchar](50) NULL,
    [SalesChannel] [varchar](50) NULL,
    [OrderPriority] [varchar](50) NULL,
    [OrderDate]  datetime,
    [OrderID] bigint NULL,
    [ShipDate] datetime,
    [UnitsSold]  float,
    [UnitPrice] float,
    [UnitCost] float,
    [TotalRevenue] float,
    [TotalCost]  float,
    [TotalProfit] float
)

The following BULK INSERT statement imports the CSV file to the Sales table.

BULK INSERT Sales
FROM 'C:\1500000 Sales Records.csv'
WITH (FIRSTROW = 2,
    FIELDTERMINATOR = ',',
    ROWTERMINATOR='\n' );

S3 limit to objects in a bucket

While you can store an unlimited number of files/objects in a single bucket, when you go to list a "directory" in a bucket, it will only give you the first 1000 files/objects in that bucket by default. To access all the files in a large "directory" like this, you need to make multiple calls to their API.

How do I tell if an object is a Promise?

ES6:

const promise = new Promise(resolve => resolve('olá'));

console.log(promise.toString().includes('Promise')); //true

Step out of current function with GDB

You can use the finish command.

finish: Continue running until just after function in the selected stack frame returns. Print the returned value (if any). This command can be abbreviated as fin.

(See 5.2 Continuing and Stepping.)

No connection could be made because the target machine actively refused it 127.0.0.1:3446

I had a similar issue. In my case the service would work fine on the developer machine but fail when on a QA machine. It turned out that on the QA machine the application wasn't being run as an administrator and didn't have permission to register the endpoint:

HTTP could not register URL http://+:12345/Foo.svc/]. Your process does not have access rights to this namespace (see http://go.microsoft.com/fwlink/?LinkId=70353 for details).

Refer here for how to get it working without being an admin user: https://stackoverflow.com/a/885765/38258

How to make image hover in css?

Hi you should give parent position relative and child absolute and give to height or width to absolute class as like this

Css

  .nkhome{
    margin-left:260px;
    width:59px;
    height:59px;
    margin-top:170px;
    position:relative;
    z-index:0;
}
.nkhome a:hover img{
    opacity:0.0;
}
.nkhome a:hover{
  background:url('http://www.prelovac.com/vladimir/wp-content/uploads/2008/03/example.jpg');
    width:100px;
    height:100px;
    position:absolute;
    top:0;
    z-index:1;

}

HTML

 <div class="nkhome">
        <a href="Home.html"><img src="http://dummyimage.com/100/000/fff.jpg" /></a>
    </div>
?

Live demo http://jsfiddle.net/t5FEX/7/


or this

<div class="nkhome">
        <a href="Home.html"><img src="http://dummyimage.com/100/000/fff.jpg" onmouseover="this.src='http://www.prelovac.com/vladimir/wp-content/uploads/2008/03/example.jpg'" 
            onmouseout="this.src='http://dummyimage.com/100/000/fff.jpg'"
            /></a>
    </div>?

Live demo http://jsfiddle.net/t5FEX/9/

Replacing all non-alphanumeric characters with empty strings

return value.replaceAll("[^A-Za-z0-9 ]", "");

This will leave spaces intact. I assume that's what you want. Otherwise, remove the space from the regex.

TensorFlow ValueError: Cannot feed value of shape (64, 64, 3) for Tensor u'Placeholder:0', which has shape '(?, 64, 64, 3)'

image has a shape of (64,64,3).

Your input placeholder _x have a shape of (?, 64,64,3).

The problem is that you're feeding the placeholder with a value of a different shape.

You have to feed it with a value of (1, 64, 64, 3) = a batch of 1 image.

Just reshape your image value to a batch with size one.

image = array(img).reshape(1, 64,64,3)

P.S: the fact that the input placeholder accepts a batch of images, means that you can run predicions for a batch of images in parallel. You can try to read more than 1 image (N images) and than build a batch of N image, using a tensor with shape (N, 64,64,3)

How to keep keys/values in same order as declared?

from collections import OrderedDict
list1 = ['k1', 'k2']
list2 = ['v1', 'v2']
new_ordered_dict = OrderedDict(zip(list1, list2))
print new_ordered_dict
# OrderedDict([('k1', 'v1'), ('k2', 'v2')])

How to Get a Sublist in C#

Would it be as easy as running a LINQ query on your List?

List<string> mylist = new List<string>{ "hello","world","foo","bar"};
List<string> listContainingLetterO = mylist.Where(x=>x.Contains("o")).ToList();

Reimport a module in python while interactive

Although the provided answers do work for a specific module, they won't reload submodules, as noted in This answer:

If a module imports objects from another module using from ... import ..., calling reload() for the other module does not redefine the objects imported from it — one way around this is to re-execute the from statement, another is to use import and qualified names (module.*name*) instead.

However, if using the __all__ variable to define the public API, it is possible to automatically reload all publicly available modules:

# Python >= 3.5
import importlib
import types


def walk_reload(module: types.ModuleType) -> None:
    if hasattr(module, "__all__"):
        for submodule_name in module.__all__:
            walk_reload(getattr(module, submodule_name))
    importlib.reload(module)


walk_reload(my_module)

The caveats noted in the previous answer are still valid though. Notably, modifying a submodule that is not part of the public API as described by the __all__ variable won't be affected by a reload using this function. Similarly, removing an element of a submodule won't be reflected by a reload.

How do you deploy Angular apps?

In order to deploy your Angular2 app to a production server, first and foremost, ensure your app runs locally on your machine.

Angular2 app can also be deployed as a node app.

So, create a node entry point file server.js/app.js (my example uses express)

var express = require('express'),
    path = require('path'),
    fs = require('fs');

var app = express();
var staticRoot = __dirname + '/';

app.set('port', (process.env.PORT || 3000));

app.use(express.static(staticRoot));

app.use(function(req, res, next){

    // if the request is not html then move along
    var accept = req.accepts('html', 'json', 'xml');
    if(accept !== 'html'){
        return next();
    }

    // if the request has a '.' assume that it's for a file, move along
    var ext = path.extname(req.path);
    if (ext !== ''){
        return next();
    }

    fs.createReadStream(staticRoot + 'index.html').pipe(res);

}); 

app.listen(app.get('port'), function() {
    console.log('app running on port', app.get('port'));
});

Also add express as a dependency in your package.json file.

Then deploy it on your preferred environment.

I have put together a small blog for deployment on IIS. follow link

What is the use of verbose in Keras while validating the model?

verbose: Integer. 0, 1, or 2. Verbosity mode.

Verbose=0 (silent)

Verbose=1 (progress bar)

Train on 186219 samples, validate on 20691 samples
Epoch 1/2
186219/186219 [==============================] - 85s 455us/step - loss: 0.5815 - acc: 
0.7728 - val_loss: 0.4917 - val_acc: 0.8029
Train on 186219 samples, validate on 20691 samples
Epoch 2/2
186219/186219 [==============================] - 84s 451us/step - loss: 0.4921 - acc: 
0.8071 - val_loss: 0.4617 - val_acc: 0.8168

Verbose=2 (one line per epoch)

Train on 186219 samples, validate on 20691 samples
Epoch 1/1
 - 88s - loss: 0.5746 - acc: 0.7753 - val_loss: 0.4816 - val_acc: 0.8075
Train on 186219 samples, validate on 20691 samples
Epoch 1/1
 - 88s - loss: 0.4880 - acc: 0.8076 - val_loss: 0.5199 - val_acc: 0.8046

Android ACTION_IMAGE_CAPTURE Intent

To follow up on Yenchi's comment above, the OK button will also do nothing if the camera app can't write to the directory in question.

That means that you can't create the file in a place that's only writeable by your application (for instance, something under getCacheDir()) Something under getExternalFilesDir() ought to work, however.

It would be nice if the camera app printed an error message to the logs if it could not write to the specified EXTRA_OUTPUT path, but I didn't find one.

RecyclerView - How to smooth scroll to top of item on a certain position?

  1. Extend "LinearLayout" class and override the necessary functions
  2. Create an instance of the above class in your fragment or activity
  3. Call "recyclerView.smoothScrollToPosition(targetPosition)

CustomLinearLayout.kt :

class CustomLayoutManager(private val context: Context, layoutDirection: Int):
  LinearLayoutManager(context, layoutDirection, false) {

    companion object {
      // This determines how smooth the scrolling will be
      private
      const val MILLISECONDS_PER_INCH = 300f
    }

    override fun smoothScrollToPosition(recyclerView: RecyclerView, state: RecyclerView.State, position: Int) {

      val smoothScroller: LinearSmoothScroller = object: LinearSmoothScroller(context) {

        fun dp2px(dpValue: Float): Int {
          val scale = context.resources.displayMetrics.density
          return (dpValue * scale + 0.5f).toInt()
        }

        // change this and the return super type to "calculateDyToMakeVisible" if the layout direction is set to VERTICAL
        override fun calculateDxToMakeVisible(view: View ? , snapPreference : Int): Int {
          return super.calculateDxToMakeVisible(view, SNAP_TO_END) - dp2px(50f)
        }

        //This controls the direction in which smoothScroll looks for your view
        override fun computeScrollVectorForPosition(targetPosition: Int): PointF ? {
          return this @CustomLayoutManager.computeScrollVectorForPosition(targetPosition)
        }

        //This returns the milliseconds it takes to scroll one pixel.
        override fun calculateSpeedPerPixel(displayMetrics: DisplayMetrics): Float {
          return MILLISECONDS_PER_INCH / displayMetrics.densityDpi
        }
      }
      smoothScroller.targetPosition = position
      startSmoothScroll(smoothScroller)
    }
  }

Note: The above example is set to HORIZONTAL direction, you can pass VERTICAL/HORIZONTAL during initialization.

If you set the direction to VERTICAL you should change the "calculateDxToMakeVisible" to "calculateDyToMakeVisible" (also mind the supertype call return value)

Activity/Fragment.kt :

...
smoothScrollerLayoutManager = CustomLayoutManager(context, LinearLayoutManager.HORIZONTAL)
recyclerView.layoutManager = smoothScrollerLayoutManager
.
.
.
fun onClick() {
  // targetPosition passed from the adapter to activity/fragment
  recyclerView.smoothScrollToPosition(targetPosition)
}

Rails: How can I set default values in ActiveRecord?

after_initialize method is deprecated, use the callback instead.

after_initialize :defaults

def defaults
  self.extras||={}
  self.other_stuff||="This stuff"
end

however, using :default in your migrations is still the cleanest way.

Java Enum return Int

In my opinion the most readable version

public enum PIN_PULL_RESISTANCE {
    PULL_UP {
        @Override
        public int getValue() {
            return 1;
        }
    },
    PULL_DOWN {
        @Override
        public int getValue() {
            return 0;
        }
    };

    public abstract int getValue();
}

How to run an android app in background?

You can probably start a Service here if you want your Application to run in Background. This is what Service in Android are used for - running in background and doing longtime operations.

UDPATE

You can use START_STICKY to make your Service running continuously.

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    handleCommand(intent);
    // We want this service to continue running until it is explicitly
    // stopped, so return sticky.
    return START_STICKY;
}

How do I set a textbox's value using an anchor with jQuery?

Following redsquare: You should not use in href attribute javascript code like "javascript:void();" - it is wrong. Better use for example href="#" and then in Your event handler as a last command: "return false;". And even better - use in href correct link - if user have javascript disabled, web browser follows the link - in this case Your webpage should reload with input filled with value of that link.

Using textures in THREE.js

Use TextureLoader to load a image as texture and then simply apply that texture to scene background.

 new THREE.TextureLoader();
     loader.load('https://images.pexels.com/photos/1205301/pexels-photo-1205301.jpeg' , function(texture)
                {
                 scene.background = texture;  
                });

Result:

https://codepen.io/hiteshsahu/pen/jpGLpq?editors=0011

See the Pen Flat Earth Three.JS by Hitesh Sahu (@hiteshsahu) on CodePen.

Microsoft Web API: How do you do a Server.MapPath?

The selected answer did not work in my Web API application. I had to use

System.Web.HttpRuntime.AppDomainAppPath

Show only two digit after decimal

How about String.format("%.2f", i2)?

Using JAXB to unmarshal/marshal a List<String>

I used @LiorH's example and expanded it to:


@XmlRootElement(name="List")
public class JaxbList<T>{
    protected List<T> list;

    public JaxbList(){}

    public JaxbList(List<T> list){
        this.list=list;
    }

    @XmlElement(name="Item")
    public List<T> getList(){
        return list;
    }
}

Note, that it uses generics so you can use it with other classes than String. Now, the application code is simply:


    @GET
    @Path("/test2")
    public JaxbList test2(){
        List list=new Vector();
        list.add("a");
        list.add("b");
        return new JaxbList(list);
    }

Why doesn't this simple class exist in the JAXB package? Anyone see anything like it elsewhere?

How do I measure the execution time of JavaScript code with callbacks?

For anyone want to get time elapsed value instead of console output :

use process.hrtime() as @D.Deriso suggestion, below is my simpler approach :

function functionToBeMeasured() {
    var startTime = process.hrtime();
    // do some task...
    // ......
    var elapsedSeconds = parseHrtimeToSeconds(process.hrtime(startTime));
    console.log('It takes ' + elapsedSeconds + 'seconds');
}

function parseHrtimeToSeconds(hrtime) {
    var seconds = (hrtime[0] + (hrtime[1] / 1e9)).toFixed(3);
    return seconds;
}

How to render a DateTime in a specific format in ASP.NET MVC 3?

works for me

<%=Model.MyDateTime.ToString("dd-MMM-yyyy")%>

How to do an array of hashmaps?

The Java Language Specification, section 15.10, states:

An array creation expression creates an object that is a new array whose elements are of the type specified by the PrimitiveType or ClassOrInterfaceType. It is a compile-time error if the ClassOrInterfaceType does not denote a reifiable type (§4.7).

and

The rules above imply that the element type in an array creation expression cannot be a parameterized type, other than an unbounded wildcard.

The closest you can do is use an unchecked cast, either from the raw type, as you have done, or from an unbounded wildcard:

 HashMap<String, String>[] responseArray = (Map<String, String>[]) new HashMap<?,?>[games.size()];

Your version is clearly better :-)

Emulating a do-while loop in Bash

We can emulate a do-while loop in Bash with while [[condition]]; do true; done like this:

while [[ current_time <= $cutoff ]]
    check_if_file_present
    #do other stuff
do true; done

For an example. Here is my implementation on getting ssh connection in bash script:

#!/bin/bash
while [[ $STATUS != 0 ]]
    ssh-add -l &>/dev/null; STATUS="$?"
    if [[ $STATUS == 127 ]]; then echo "ssh not instaled" && exit 0;
    elif [[ $STATUS == 2 ]]; then echo "running ssh-agent.." && eval `ssh-agent` > /dev/null;
    elif [[ $STATUS == 1 ]]; then echo "get session identity.." && expect $HOME/agent &> /dev/null;
    else ssh-add -l && git submodule update --init --recursive --remote --merge && return 0; fi
do true; done

It will give the output in sequence as below:

Step #0 - "gcloud": intalling expect..
Step #0 - "gcloud": running ssh-agent..
Step #0 - "gcloud": get session identity..
Step #0 - "gcloud": 4096 SHA256:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX /builder/home/.ssh/id_rsa (RSA)
Step #0 - "gcloud": Submodule '.google/cloud/compute/home/chetabahana/.docker/compose' ([email protected]:chetabahana/compose) registered for path '.google/cloud/compute/home/chetabahana/.docker/compose'
Step #0 - "gcloud": Cloning into '/workspace/.io/.google/cloud/compute/home/chetabahana/.docker/compose'...
Step #0 - "gcloud": Warning: Permanently added the RSA host key for IP address 'XXX.XX.XXX.XXX' to the list of known hosts.
Step #0 - "gcloud": Submodule path '.google/cloud/compute/home/chetabahana/.docker/compose': checked out '24a28a7a306a671bbc430aa27b83c09cc5f1c62d'
Finished Step #0 - "gcloud"

Load image from resources area of project in C#

Or you could use this line when dealing with WPF or Silverlight, especially where you have the source string already in the XAML markup:

(ImageSource)new ImageSourceConverter().ConvertFromString(ImagePath);

Where the ImagePath is something like:

string ImagePath  = "/ProjectName;component/Resource/ImageName.png";

Changing button color programmatically

I have finally found a working code - try this:

document.getElementById("button").style.background='#000000';

Is there any kind of hash code function in JavaScript?

My solution introduces a static function for the global Object object.

(function() {
    var lastStorageId = 0;

    this.Object.hash = function(object) {
        var hash = object.__id;

        if (!hash)
             hash = object.__id = lastStorageId++;

        return '#' + hash;
    };
}());

I think this is more convenient with other object manipulating functions in JavaScript.

Reading/writing an INI file

There is an Ini Parser available in CommonLibrary.NET

This has various very convenient overloads for getting sections/values and is very light weight.

Fetch first element which matches criteria

This might be what you are looking for:

yourStream
    .filter(/* your criteria */)
    .findFirst()
    .get();

And better, if there's a possibility of matching no element, in which case get() will throw a NPE. So use:

yourStream
    .filter(/* your criteria */)
    .findFirst()
    .orElse(null); /* You could also create a default object here */


An example:
public static void main(String[] args) {
    class Stop {
        private final String stationName;
        private final int    passengerCount;

        Stop(final String stationName, final int passengerCount) {
            this.stationName    = stationName;
            this.passengerCount = passengerCount;
        }
    }

    List<Stop> stops = new LinkedList<>();

    stops.add(new Stop("Station1", 250));
    stops.add(new Stop("Station2", 275));
    stops.add(new Stop("Station3", 390));
    stops.add(new Stop("Station2", 210));
    stops.add(new Stop("Station1", 190));

    Stop firstStopAtStation1 = stops.stream()
            .filter(e -> e.stationName.equals("Station1"))
            .findFirst()
            .orElse(null);

    System.out.printf("At the first stop at Station1 there were %d passengers in the train.", firstStopAtStation1.passengerCount);
}

Output is:

At the first stop at Station1 there were 250 passengers in the train.

Using NOT operator in IF conditions

try like this

if (!(a | b)) {
    //blahblah
}

It's same with

if (a | b) {}
else {
    // blahblah
}

How to make a browser display a "save as dialog" so the user can save the content of a string to a file on his system?

This is possible using this cross browser javascript implementation of the HTML5 saveAs function: https://github.com/koffsyrup/FileSaver.js

If all you want to do is save text then the above script works in all browsers(including all versions of IE), using nothing but JS.

AWS EFS vs EBS vs S3 (differences & when to use?)

In simple words

Amazon EBS provides block level storage .

Amazon EFS provides network-attached shared file storage.

Amazon S3 provides object storage .

What is the use of the init() usage in JavaScript?

In JavaScript when you create any object through a constructor call like below

step 1 : create a function say Person..

function Person(name){
this.name=name;
}
person.prototype.print=function(){
console.log(this.name);
}

step 2 : create an instance for this function..

var obj=new Person('venkat')

//above line will instantiate this function(Person) and return a brand new object called Person {name:'venkat'}

if you don't want to instantiate this function and call at same time.we can also do like below..

var Person = {
  init: function(name){
    this.name=name;
  },
  print: function(){
    console.log(this.name);
  }
};
var obj=Object.create(Person);
obj.init('venkat');
obj.print();

in the above method init will help in instantiating the object properties. basically init is like a constructor call on your class.

How do I use two submit buttons, and differentiate between which one was used to submit the form?

You can use it as follows,

<td>

<input type="submit" name="save" class="noborder" id="save" value="Save" alt="Save" 
tabindex="4" />

</td>

<td>

<input type="submit" name="publish" class="noborder" id="publish" value="Publish" 
alt="Publish" tabindex="5" />

</td>

And in PHP,

<?php
if($_POST['save'])
{
   //Save Code
}
else if($_POST['publish'])
{
   //Publish Code
}
?>

PHP Convert String into Float/Double

Try using

$string = "2968789218";
$float = (double)$string;

How to create new div dynamically, change it, move it, modify it in every way possible, in JavaScript?

This covers the basics of DOM manipulation. Remember, element addition to the body or a body-contained node is required for the newly created node to be visible within the document.

How to implement a secure REST API with node.js

I just finished a sample app that does this in a pretty basic, but clear way. It uses mongoose with mongodb to store users and passport for auth management.

https://github.com/Khelldar/Angular-Express-Train-Seed

Creating temporary files in bash

Yes, use mktemp.

It will create a temporary file inside a folder that is designed for storing temporary files, and it will guarantee you a unique name. It outputs the name of that file:

> mktemp
/tmp/tmp.xx4mM3ePQY
>

CFLAGS vs CPPFLAGS

To add to those who have mentioned the implicit rules, it's best to see what make has defined implicitly and for your env using:

make -p

For instance:

%.o: %.c
    $(COMPILE.c) $(OUTPUT_OPTION) $<

which expands

COMPILE.c = $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c

This will also print # environment data. Here, you will find GCC's include path among other useful info.

C_INCLUDE_PATH=/usr/include

In make, when it comes to search, the paths are many, the light is one... or something to that effect.

  1. C_INCLUDE_PATH is system-wide, set it in your shell's *.rc.
  2. $(CPPFLAGS) is for the preprocessor include path.
  3. If you need to add a general search path for make, use:
VPATH = my_dir_to_search

... or even more specific

vpath %.c src
vpath %.h include

make uses VPATH as a general search path so use cautiously. If a file exists in more than one location listed in VPATH, make will take the first occurrence in the list.

Loop through a Map with JSTL

You can loop through a hash map like this

<%
ArrayList list = new ArrayList();
TreeMap itemList=new TreeMap();
itemList.put("test", "test");
list.add(itemList);
pageContext.setAttribute("itemList", list);                            
%>

  <c:forEach items="${itemList}" var="itemrow">
   <input  type="text"  value="<c:out value='${itemrow.test}'/>"/>
  </c:forEach>               

For more JSTL functionality look here

How to find which columns contain any NaN value in Pandas dataframe

You can use df.isnull().sum(). It shows all columns and the total NaNs of each feature.

Using an array as needles in strpos

If you just want to check if certain characters are actually in the string or not, use strtok:

$string = 'abcdefg';
if (strtok($string, 'acd') === $string) {
    // not found
} else {
    // found
}

Loading inline content using FancyBox

The way I figured this out was going through the example index.html/style.css that comes packaged with the Fancybox installation.

If you view the code that is used for the demo website and basically copy/paste, you'll be fine.

To get an inline Fancybox working, you will need to have this code present in your index.html file:

  <head>
    <link href="./fancybox/jquery.fancybox-1.3.4.css" rel="stylesheet" type="text/css" media="screen" />
    <script>!window.jQuery && document.write('<script src="jquery-1.4.3.min.js"><\/script>');</script>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
    <script type="text/javascript" src="./fancybox/jquery.fancybox-1.3.4.pack.js"></script>
    <script type="text/javascript">
    $(document).ready(function() {

    $("#various1").fancybox({
            'titlePosition'     : 'inside',
            'transitionIn'      : 'none',
            'transitionOut'     : 'none'
        });
    });
    </script>
  </head>

 <body>

    <a id="various1" href="#inline1" title="Put a title here">Name of Link Here</a>
    <div style="display: none;">
        <div id="inline1" style="width:400px;height:100px;overflow:auto;">
                   Write whatever text you want right here!!
        </div>
    </div> 

</body>

Remember to be precise about what folders your script files are placed in and where you are pointing to in the Head tag; they must correspond.

How to increase Neo4j's maximum file open limit (ulimit) in Ubuntu?

I am using Debian but this solution should work fine with Ubuntu.
You have to add a line in the neo4j-service script.
Here is what I have done :

nano /etc/init.d/neo4j-service
Add « ulimit –n 40000 » just before the start-stop-daemon line in the do_start section

Note that I am using version 2.0 Enterprise edition. Hope this will help you.

For loop example in MySQL

While loop syntax example in MySQL:

delimiter //

CREATE procedure yourdatabase.while_example()
wholeblock:BEGIN
  declare str VARCHAR(255) default '';
  declare x INT default 0;
  SET x = 1;

  WHILE x <= 5 DO
    SET str = CONCAT(str,x,',');
    SET x = x + 1;
  END WHILE;

  select str;
END//

Which prints:

mysql> call while_example();
+------------+
| str        |
+------------+
| 1,2,3,4,5, |
+------------+

REPEAT loop syntax example in MySQL:

delimiter //

CREATE procedure yourdb.repeat_loop_example()
wholeblock:BEGIN
  DECLARE x INT;
  DECLARE str VARCHAR(255);
  SET x = 5;
  SET str = '';

  REPEAT
    SET str = CONCAT(str,x,',');
    SET x = x - 1;
    UNTIL x <= 0
  END REPEAT;

  SELECT str;
END//

Which prints:

mysql> call repeat_loop_example();
+------------+
| str        |
+------------+
| 5,4,3,2,1, |
+------------+

FOR loop syntax example in MySQL:

delimiter //

CREATE procedure yourdatabase.for_loop_example()
wholeblock:BEGIN
  DECLARE x INT;
  DECLARE str VARCHAR(255);
  SET x = -5;
  SET str = '';

  loop_label: LOOP
    IF x > 0 THEN
      LEAVE loop_label;
    END IF;
    SET str = CONCAT(str,x,',');
    SET x = x + 1;
    ITERATE loop_label;
  END LOOP;

  SELECT str;

END//

Which prints:

mysql> call for_loop_example();
+-------------------+
| str               |
+-------------------+
| -5,-4,-3,-2,-1,0, |
+-------------------+
1 row in set (0.00 sec)

Do the tutorial: http://www.mysqltutorial.org/stored-procedures-loop.aspx

If I catch you pushing this kind of MySQL for-loop constructs into production, I'm going to shoot you with the foam missile launcher. You can use a pipe wrench to bang in a nail, but doing so makes you look silly.

How to add meta tag in JavaScript

Try

_x000D_
_x000D_
document.head.innerHTML += '<meta http-equiv="X-UA-..." content="IE=edge">'
_x000D_
_x000D_
_x000D_

CSS force image resize and keep aspect ratio

I would suggest for a responsive approach the best practice would be using the Viewport units and min/max attributes as follows:

img{
  display: block;
  width: 12vw;
  height:12vw;
  max-width:100%;
  min-width:100px;
  min-height:100px;
  object-fit:contain;
}

How to find all positions of the maximum value in a list?

>>> max(enumerate([1,2,3,32,1,5,7,9]),key=lambda x: x[1])
>>> (3, 32)

regex pattern to match the end of a string

Should be

~/([^/]*)$~

Means: Match a / and then everything, that is not a / ([^/]*) until the end ($, "end"-anchor).

I use the ~ as delimiter, because now I don't need to escape the forward-slash /.

Regex to accept alphanumeric and some special character in Javascript?

use:

/^[ A-Za-z0-9_@./#&+-]*$/

You can also use the character class \w to replace A-Za-z0-9_

Android emulator doesn't take keyboard input - SDK tools rev 20

Recreating an AVD with the Hardware Keyboard + setting the boolean to true was the only solution that worked for me; the other two main solutions (terminal or editing an existing AVD via GUI) both resulted in software/emulator crashes on my Mac. Making a new AVD resulted in the keyboard working just fine.

Python 2.7.10 error "from urllib.request import urlopen" no module named request

from urllib.request import urlopen, Request

Should solve everything

How to change language of app when user selects language?

Good solutions explained pretty well here. But Here is one more.

Create your own CustomContextWrapper class extending ContextWrapper and use it to change Locale setting for the complete application. Here is a GIST with usage.

And then call the CustomContextWrapper with saved locale identifier e.g. 'hi' for Hindi language in activity lifecycle method attachBaseContext. Usage here:

@Override
protected void attachBaseContext(Context newBase) {
    // fetch from shared preference also save the same when applying. Default here is en = English
    String language = MyPreferenceUtil.getInstance().getString("saved_locale", "en");
    super.attachBaseContext(MyContextWrapper.wrap(newBase, language));
}

Should I use JSLint or JSHint JavaScript validation?

Foreword: Well, that escalated quickly. But decided to pull it through. May this answer be helpful to you and other readers.

I got a bit carried away here

Code Hinting

While JSLint and JSHint are good tools to use, over the years I've come to appreciate what my friend @ugly_syntax calls:

smaller design space.

This is a general principle, much like a "zen monk", limiting the choices one has to make, one can be more productive and creative.

Therefore my current favourite zero-config JS code style:

StandardJS.

UPDATE:

Flow has improved a lot. With it, you can add types to your JS with will help you prevent a lot of bugs. But it can also stay out of your way, for instance when interfacing untyped JS. Give it a try!

Quickstart / TL;DR

Add standard as a dependency to you project

npm install --save standard

Then in package.json, add the following test script:

"scripts": {
    "test": "node_modules/.bin/standard && echo put further tests here"
},

For snazzier output while developing, npm install --global snazzy and run it instead of npm test.

Note: Type checking versus Heuristics

My friend when mentioning design space referred to Elm and I encourage you to give that language a try.

Why? JS is in fact inspired by LISP, which is a special class of languages, which happens to be untyped. Language such as Elm or Purescript are typed functional programming languages.

Type restrict your freedom in order for the compiler to be able to check and guide you when you end up violation the language or your own program's rules; regardless of the size (LOC) of your program.

We recently had a junior colleague implement a reactive interface twice: once in Elm, once in React; have a look to get some idea of what I'm talking about.

Compare Main.elm (typed) ? index.js (untyped, no tests)

(ps. note that the React code is not idiomatic and could be improved)

One final remark,

the reality is that JS is untyped. Who am I to suggest typed programming to you?

See, with JS we are in a different domain: freed from types, we can easily express things that are hard or impossible to give a proper type (which can certainly be an advantage).

But without types there is little to keep our programs in check, so we are forced to introduce tests and (to a lesser extend) code styles.

I recommend you look at LISP (e.g. ClojureScript) for inspiration and invest in testing your codes. Read The way of the substack to get an idea.

Peace.

How to disable mouse scroll wheel scaling with Google Maps API

Keep it simple! Original Google maps variable, none of the extra stuff.

 var mapOptions = {
     zoom: 16,
     center: myLatlng,
     scrollwheel: false

}