Programs & Examples On #Visual studio shell

Visual Studio Shell is used to create custom tool having an integrated development environment (IDE) similar to VS.

How to specify multiple conditions in an if statement in javascript

Sometimes you can find tricks to further combine statments.

Like for example:

0 + 0 = 0

and

"" + 0 = 0

so

PageCount == 0
PageCount == ''

can be written like:

PageCount+0 == 0

In javascript 0 is just as good as false inverting ! it would turn 0 into true

!PageCount+0

for a grand total of:

if ( Type == 2 && !PageCount+0 ) PageCount = elm.value;

How do I set the figure title and axes labels font size in Matplotlib?

Others have provided answers for how to change the title size, but as for the axes tick label size, you can also use the set_tick_params method.

E.g., to make the x-axis tick label size small:

ax.xaxis.set_tick_params(labelsize='small')

or, to make the y-axis tick label large:

ax.yaxis.set_tick_params(labelsize='large')

You can also enter the labelsize as a float, or any of the following string options: 'xx-small', 'x-small', 'small', 'medium', 'large', 'x-large', or 'xx-large'.

Find and copy files

The reason for that error is that you are trying to copy a folder which requires -r option also to cp Thanks

How to send a GET request from PHP?

Depending on whether your php setup allows fopen on URLs, you could also simply fopen the url with the get arguments in the string (such as http://example.com?variable=value )

Edit: Re-reading the question I'm not certain whether you're looking to pass variables or not - if you're not you can simply send the fopen request containg http://example.com/filename.xml - feel free to ignore the variable=value part

Using ChildActionOnly in MVC

With [ChildActionOnly] attribute annotated, an action method can be called only as a child method from within a view. Here is an example for [ChildActionOnly]..

there are two action methods: Index() and MyDateTime() and corresponding Views: Index.cshtml and MyDateTime.cshtml. this is HomeController.cs

public class HomeController : Controller
 {
    public ActionResult Index()
    {
        ViewBag.Message = "This is from Index()";
        var model = DateTime.Now;
        return View(model);
    }

    [ChildActionOnly]
    public PartialViewResult MyDateTime()
    {
        ViewBag.Message = "This is from MyDateTime()";

        var model = DateTime.Now;
        return PartialView(model);
    } 
}

Here is the view for Index.cshtml.

@model DateTime
@{
    ViewBag.Title = "Index";
}
<h2>
    Index</h2>
<div>
    This is the index view for Home : @Model.ToLongTimeString()
</div>
<div>
    @Html.Action("MyDateTime")  // Calling the partial view: MyDateTime().
</div>

<div>
    @ViewBag.Message
</div>

Here is MyDateTime.cshtml partial view.

@model DateTime

<p>
This is the child action result: @Model.ToLongTimeString()
<br />
@ViewBag.Message
</p>
 if you run the application and do this request http://localhost:57803/home/mydatetime
 The result will be Server Error like so: 

enter image description here

This means you can not directly call the partial view. but it can be called via Index() view as in the Index.cshtml

     @Html.Action("MyDateTime")  // Calling the partial view: MyDateTime().
 

If you remove [ChildActionOnly] and do the same request http://localhost:57803/home/mydatetime it allows you to get the mydatetime partial view result:
This is the child action result. 12:53:31 PM 
This is from MyDateTime()

Return zero if no record is found

You can also try: (I tried this and it worked for me)

SELECT ISNULL((SELECT SUM(columnA) FROM my_table WHERE columnB = 1),0)) INTO res;

How to replace comma with a dot in the number (or any replacement)

As replace() creates/returns a new string rather than modifying the original (tt), you need to set the variable (tt) equal to the new string returned from the replace function.

tt = tt.replace(/,/g, '.')

JSFiddle

How to listen state changes in react.js?

Since React 16.8 in 2019 with useState and useEffect Hooks, following are now equivalent (in simple cases):

AngularJS:

$scope.name = 'misko'
$scope.$watch('name', getSearchResults)

<input ng-model="name" />

React:

const [name, setName] = useState('misko')
useEffect(getSearchResults, [name])

<input value={name} onChange={e => setName(e.target.value)} />

Efficiency of Java "Double Brace Initialization"?

Efficiency aside, I rarely find myself wishing for declarative collection creation outside of unit tests. I do believe that the double brace syntax is very readable.

Another way to achieve the declarative construction of lists specifically is to use Arrays.asList(T ...) like so:

List<String> aList = Arrays.asList("vanilla", "strawberry", "chocolate");

The limitation of this approach is of course that you cannot control the specific type of list to be generated.

Possible to make labels appear when hovering over a point in matplotlib?

I have made a multi-line annotation system to add to: https://stackoverflow.com/a/47166787/10302020. for the most up to date version: https://github.com/AidenBurgess/MultiAnnotationLineGraph

Simply change the data in the bottom section.

import matplotlib.pyplot as plt


def update_annot(ind, line, annot, ydata):
    x, y = line.get_data()
    annot.xy = (x[ind["ind"][0]], y[ind["ind"][0]])
    # Get x and y values, then format them to be displayed
    x_values = " ".join(list(map(str, ind["ind"])))
    y_values = " ".join(str(ydata[n]) for n in ind["ind"])
    text = "{}, {}".format(x_values, y_values)
    annot.set_text(text)
    annot.get_bbox_patch().set_alpha(0.4)


def hover(event, line_info):
    line, annot, ydata = line_info
    vis = annot.get_visible()
    if event.inaxes == ax:
        # Draw annotations if cursor in right position
        cont, ind = line.contains(event)
        if cont:
            update_annot(ind, line, annot, ydata)
            annot.set_visible(True)
            fig.canvas.draw_idle()
        else:
            # Don't draw annotations
            if vis:
                annot.set_visible(False)
                fig.canvas.draw_idle()


def plot_line(x, y):
    line, = plt.plot(x, y, marker="o")
    # Annotation style may be changed here
    annot = ax.annotate("", xy=(0, 0), xytext=(-20, 20), textcoords="offset points",
                        bbox=dict(boxstyle="round", fc="w"),
                        arrowprops=dict(arrowstyle="->"))
    annot.set_visible(False)
    line_info = [line, annot, y]
    fig.canvas.mpl_connect("motion_notify_event",
                           lambda event: hover(event, line_info))


# Your data values to plot
x1 = range(21)
y1 = range(0, 21)
x2 = range(21)
y2 = range(0, 42, 2)
# Plot line graphs
fig, ax = plt.subplots()
plot_line(x1, y1)
plot_line(x2, y2)
plt.show()

Working copy locked error in tortoise svn while committing

If this (https://stackoverflow.com/a/11764922/3045875) does not help: Check if another SVN tool is interfering and close the tool. We just struggled a couple of hours at merging using TortoiseSVN and had dozens of such lock errors. Eventually we figured that Matlabs SVN integration is interfering and after closing it all worked out.

Pass a variable to a PHP script running from the command line

These lines will convert the arguments of a CLI call like php myfile.php "type=daily&foo=bar" into the well known $_GET-array:

if (!empty($argv[1])) {
  parse_str($argv[1], $_GET);
}

Though it is rather messy to overwrite the global $_GET-array, it converts all your scripts quickly to accept CLI arguments.

See parse_str for details.

Using CSS to insert text

The answer using jQuery that everyone seems to like has a major flaw, which is it is not scalable (at least as it is written). I think Martin Hansen has the right idea, which is to use HTML5 data-* attributes. And you can even use the apostrophe correctly:

html:

<div class="task" data-task-owner="Joe">mop kitchen</div>
<div class="task" data-task-owner="Charles" data-apos="1">vacuum hallway</div>

css:

div.task:before { content: attr(data-task-owner)"'s task - " ; }
div.task[data-apos]:before { content: attr(data-task-owner)"' task - " ; }

output:

Joe's task - mop kitchen
Charles' task - vacuum hallway

Curl error 60, SSL certificate issue: self signed certificate in certificate chain

Important: This issue drove me crazy for a couple days and I couldn't figure out what was going on with my curl & openssl installations. I finally figured out that it was my intermediate certificate (in my case, GoDaddy) which was out of date. I went back to my godaddy SSL admin panel, downloaded the new intermediate certificate, and the issue disappeared.

I'm sure this is the issue for some of you.

Apparently, GoDaddy had changed their intermediate certificate at some point, due to scurity issues, as they now display this warning:

"Please be sure to use the new SHA-2 intermediate certificates included in your downloaded bundle."

Hope this helps some of you, because I was going nuts and this cleaned up the issue on ALL my servers.

Mocha / Chai expect.to.throw not catching thrown errors

And if you are already using ES6/ES2015 then you can also use an arrow function. It is basically the same as using a normal anonymous function but shorter.

expect(() => model.get('z')).to.throw('Property does not exist in model schema.');

What is the simplest C# function to parse a JSON string into an object?

Just use the Json.NET library. It lets you parse Json format strings very easily:

JObject o = JObject.Parse(@"
{
    ""something"":""value"",
    ""jagged"":
    {
        ""someother"":""value2""
    }
}");

string something = (string)o["something"];

Documentation: Parsing JSON Object using JObject.Parse

Is there a way to list open transactions on SQL Server 2000 database?

DBCC OPENTRAN helps to identify active transactions that may be preventing log truncation. DBCC OPENTRAN displays information about the oldest active transaction and the oldest distributed and nondistributed replicated transactions, if any, within the transaction log of the specified database. Results are displayed only if there is an active transaction that exists in the log or if the database contains replication information.

An informational message is displayed if there are no active transactions in the log.

DBCC OPENTRAN

EditText underline below text property

You can do it with AppCompatEditText and color selector:

            <androidx.appcompat.widget.AppCompatEditText
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:backgroundTint="@color/selector_edittext_underline" />

selector_edittext_underline.xml:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@color/focused_color" 
          android:state_focused="true" />
    <item android:color="@color/hint_color" />
</selector>

NOTE: Put this selector file in res/color folder, not res/drawable. ususually res/color does not exist and we may have to create it.

Easiest way to convert a Blob into a byte array

the mySql blob class has the following function :

blob.getBytes

use it like this:

//(assuming you have a ResultSet named RS)
Blob blob = rs.getBlob("SomeDatabaseField");

int blobLength = (int) blob.length();  
byte[] blobAsBytes = blob.getBytes(1, blobLength);

//release the blob and free up memory. (since JDBC 4.0)
blob.free();

How to import component into another root component in Angular 2

above answers In simple words, you have to register under @NgModule's

declarations: [
    AppComponent, YourNewComponentHere
  ] 

of app.module.ts

do not forget to import that component.

Replace None with NaN in pandas dataframe

If you use df.replace([None], np.nan, inplace=True), this changed all datetime objects with missing data to object dtypes. So now you may have broken queries unless you change them back to datetime which can be taxing depending on the size of your data.

If you want to use this method, you can first identify the object dtype fields in your df and then replace the None:

obj_columns = list(df.select_dtypes(include=['object']).columns.values)
df[obj_columns] = df[obj_columns].replace([None], np.nan)

Calling Scalar-valued Functions in SQL

Can do the following

PRINT dbo.[FunctionName] ( [Parameter/Argument] )

E.g.:

PRINT dbo.StringSplit('77,54')

Python read-only property

I am dissatisfied with the previous two answers to create read only properties because the first solution allows the readonly attribute to be deleted and then set and doesn't block the __dict__. The second solution could be worked around with testing - finding the value that equals what you set it two and changing it eventually.

Now, for the code.

def final(cls):
    clss = cls
    @classmethod
    def __init_subclass__(cls, **kwargs):
        raise TypeError("type '{}' is not an acceptable base type".format(clss.__name__))
    cls.__init_subclass__ = __init_subclass__
    return cls


def methoddefiner(cls, method_name):
    for clss in cls.mro():
        try:
            getattr(clss, method_name)
            return clss
        except(AttributeError):
            pass
    return None
            
            
def readonlyattributes(*attrs):
    """Method to create readonly attributes in a class
    
    Use as a decorator for a class. This function takes in unlimited 
    string arguments for names of readonly attributes and returns a
    function to make the readonly attributes readonly. 
    
    The original class's __getattribute__, __setattr__, and __delattr__ methods
    are redefined so avoid defining those methods in the decorated class
    
    You may create setters and deleters for readonly attributes, however
    if they are overwritten by the subclass, they lose access to the readonly
    attributes. 
    
    Any method which sets or deletes a readonly attribute within
    the class loses access if overwritten by the subclass besides the __new__
    or __init__ constructors.
    
    This decorator doesn't support subclassing of these classes
    """
    def classrebuilder(cls):
        def __getattribute__(self, name):
            if name == '__dict__':
                    from types import MappingProxyType
                    return MappingProxyType(super(cls, self).__getattribute__('__dict__'))
            return super(cls, self).__getattribute__(name)
        def __setattr__(self, name, value): 
                if name == '__dict__' or name in attrs:
                    import inspect
                    stack = inspect.stack()
                    try:
                        the_class = stack[1][0].f_locals['self'].__class__
                    except(KeyError):
                        the_class = None
                    the_method = stack[1][0].f_code.co_name
                    if the_class != cls: 
                         if methoddefiner(type(self), the_method) != cls:
                            raise AttributeError("Cannot set readonly attribute '{}'".format(name))                        
                return super(cls, self).__setattr__(name, value)
        def __delattr__(self, name):                
                if name == '__dict__' or name in attrs:
                    import inspect
                    stack = inspect.stack()
                    try:
                        the_class = stack[1][0].f_locals['self'].__class__
                    except(KeyError):
                        the_class = None
                    the_method = stack[1][0].f_code.co_name
                    if the_class != cls:
                        if methoddefiner(type(self), the_method) != cls:
                            raise AttributeError("Cannot delete readonly attribute '{}'".format(name))                        
                return super(cls, self).__delattr__(name)
        clss = cls
        cls.__getattribute__ = __getattribute__
        cls.__setattr__ = __setattr__
        cls.__delattr__ = __delattr__
        #This line will be moved when this algorithm will be compatible with inheritance
        cls = final(cls)
        return cls
    return classrebuilder

def setreadonlyattributes(cls, *readonlyattrs):
    return readonlyattributes(*readonlyattrs)(cls)


if __name__ == '__main__':
    #test readonlyattributes only as an indpendent module
    @readonlyattributes('readonlyfield')
    class ReadonlyFieldClass(object):
        def __init__(self, a, b):
            #Prevent initalization of the internal, unmodified PrivateFieldClass
            #External PrivateFieldClass can be initalized
            self.readonlyfield = a
            self.publicfield = b
            

    attr = None
    def main():
        global attr
        pfi = ReadonlyFieldClass('forbidden', 'changable')
        ###---test publicfield, ensure its mutable---###
        try:
            #get publicfield
            print(pfi.publicfield)
            print('__getattribute__ works')
            #set publicfield
            pfi.publicfield = 'mutable'
            print('__setattr__ seems to work')
            #get previously set publicfield
            print(pfi.publicfield)
            print('__setattr__ definitely works')
            #delete publicfield
            del pfi.publicfield 
            print('__delattr__ seems to work')
            #get publicfield which was supposed to be deleted therefore should raise AttributeError
            print(pfi.publlicfield)
            #publicfield wasn't deleted, raise RuntimeError
            raise RuntimeError('__delattr__ doesn\'t work')
        except(AttributeError):
            print('__delattr__ works')
        
        
        try:
            ###---test readonly, make sure its readonly---###
            #get readonlyfield
            print(pfi.readonlyfield)
            print('__getattribute__ works')
            #set readonlyfield, should raise AttributeError
            pfi.readonlyfield = 'readonly'
            #apparently readonlyfield was set, notify user
            raise RuntimeError('__setattr__ doesn\'t work')
        except(AttributeError):
            print('__setattr__ seems to work')
            try:
                #ensure readonlyfield wasn't set
                print(pfi.readonlyfield)
                print('__setattr__ works')
                #delete readonlyfield
                del pfi.readonlyfield
                #readonlyfield was deleted, raise RuntimeError
                raise RuntimeError('__delattr__ doesn\'t work')
            except(AttributeError):
                print('__delattr__ works')
        try:
            print("Dict testing")
            print(pfi.__dict__, type(pfi.__dict__))
            attr = pfi.readonlyfield
            print(attr)
            print("__getattribute__ works")
            if pfi.readonlyfield != 'forbidden':
                print(pfi.readonlyfield)
                raise RuntimeError("__getattr__ doesn't work")
            try:
                pfi.__dict__ = {}
                raise RuntimeError("__setattr__ doesn't work")
            except(AttributeError):
                print("__setattr__ works")
            del pfi.__dict__
            raise RuntimeError("__delattr__ doesn't work")
        except(AttributeError):
            print(pfi.__dict__)
            print("__delattr__ works")
            print("Basic things work")


main()
        

There is no point to making read only attributes except when your writing library code, code which is being distributed to others as code to use in order to enhance their programs, not code for any other purpose, like app development. The __dict__ problem is solved, because the __dict__ is now of the immutable types.MappingProxyType, so attributes cannot be changed through the __dict__. Setting or deleting __dict__ is also blocked. The only way to change read only properties is through changing the methods of the class itself.

Though I believe my solution is better than of the previous two, it could be improved. These are this code's weaknesses:

  1. Doesn't allow adding to a method in a subclass which sets or deletes a readonly attribute. A method defined in a subclass is automatically barred from accessing a readonly attribute, even by calling the superclass' version of the method.

  2. The class' readonly methods can be changed to defeat the read only restrictions.

However, there is not way without editing the class to set or delete a read only attribute. This isn't dependent on naming conventions, which is good because Python isn't so consistent with naming conventions. This provides a way to make read only attributes that cannot be changed with hidden loopholes without editing the class itself. Simply list the attributes to be read only when calling the decorator as arguments and they will become read only.

Credit to Brice's answer for getting the caller classes and methods.

Database design for a survey

Having a large Answer table, in and of itself, is not a problem. As long as the indexes and constraints are well defined you should be fine. Your second schema looks good to me.

How organize uploaded media in WP?

I don't believe this can be done "out of the box" in wordpress; The closest thing is storing media uploads by date-based subfolders, as per the option Organize my uploads into month- and year-based folders on the media settings screen.

Next best might be to create a "dummy" page hierarchy that serves as your folder tree, and then attach your images to these. This would give you a logical grouping, which could exist in relative isolation from your actual page or post hierarchy. But of course this won't give you the files organised like this in the file system, eg you couldn't of course FTP to this structure.

Otherwise I think you'll need to find a plugin or write something yourself to handle this.

Some plugins I found after a quick google for "wordpress plugin media folders":

While these might not be precisely what you want, they might give you clues/direction towards implementing something yourself. (Although that first one looks promising.)

Just FYI at least one similar question has been asked over on Wordpress.stackexchange:

https://wordpress.stackexchange.com/questions/13030/media-library-plugins-for-better-file-management

It might pay to have a good hunt about over there for something more substantial . Good luck!

How to trigger Jenkins builds remotely and to pass parameters

In your Jenkins job configuration, tick the box named "This build is parameterized", click the "Add Parameter" button and select the "String Parameter" drop down value.

Now define your parameter - example:

Enter image description here

Now you can use your parameter in your job / build pipeline, example:

Enter image description here

Next to trigger the build with own/custom parameter, invoke the following URL (using either POST or GET):

http://JENKINS_SERVER_ADDRESS/job/YOUR_JOB_NAME/buildWithParameters?myparam=myparam_value

If two cells match, return value from third

All you have to do is write an IF condition in the column d like this:

=IF(A1=C1;B1;" ")

After that just apply this formula to all rows above that one.

On npm install: Unhandled rejection Error: EACCES: permission denied

sudo chown -R $(whoami) ~/.npm

sudo chown -R $(whoami) ~/.config

How to use auto-layout to move other views when a view is hidden?

For the Googlers: building on Max's answer, to solve the padding issue that many have noticed I simply increased the height of the label and used that height as the separator instead of actual padding. This idea could be expanded for any scenario with containing views.

Here's a simple example:

IB Screenshot

In this case, I map the height of the Author label to an appropriate IBOutlet:

@property (retain, nonatomic) IBOutlet NSLayoutConstraint* authorLabelHeight;

and when I set the height of the constraint to 0.0f, we preserve the "padding", because the Play button's height allows for it.

How to download a Nuget package without nuget.exe or Visual Studio extension?

To obtain the current stable version of the NuGet package use:

https://www.nuget.org/api/v2/package/{packageID}

How to update/modify an XML file in python?

What you really want to do is use an XML parser and append the new elements with the API provided.

Then simply overwrite the file.

The easiest to use would probably be a DOM parser like the one below:

http://docs.python.org/library/xml.dom.minidom.html

HTML5 Canvas Rotate Image

This is the simplest code to draw a rotated and scaled image:

function drawImage(ctx, image, x, y, w, h, degrees){
  ctx.save();
  ctx.translate(x+w/2, y+h/2);
  ctx.rotate(degrees*Math.PI/180.0);
  ctx.translate(-x-w/2, -y-h/2);
  ctx.drawImage(image, x, y, w, h);
  ctx.restore();
}

How can I get the size of an std::vector as an int?

In the first two cases, you simply forgot to actually call the member function (!, it's not a value) std::vector<int>::size like this:

#include <vector>

int main () {
    std::vector<int> v;
    auto size = v.size();
}

Your third call

int size = v.size();

triggers a warning, as not every return value of that function (usually a 64 bit unsigned int) can be represented as a 32 bit signed int.

int size = static_cast<int>(v.size());

would always compile cleanly and also explicitly states that your conversion from std::vector::size_type to int was intended.

Note that if the size of the vector is greater than the biggest number an int can represent, size will contain an implementation defined (de facto garbage) value.

A table name as a variable

You need to use the SQL Server dynamic SQL:

DECLARE @table     NVARCHAR(128),
        @sql       NVARCHAR(MAX);

SET @table = N'tableName';

SET @sql = N'SELECT * FROM ' + @table;

Use EXEC to execute any SQL:

EXEC (@sql)

Use EXEC sp_executesql to execute any SQL:

EXEC sp_executesql @sql;

Use EXECUTE sp_executesql to execute any SQL:

EXECUTE sp_executesql @sql

Can't find file executable in your configured search path for gnc gcc compiler

* How to Download and install CodeBlocks.* ( I have already downloaded )


***How to solve the CodeBlocks environment error.

  1. Go to "Settings"----"Compiler"----"Selected compiler"( GNU GCC Compiler ).

  2. Then, Selected "Toolchain executables".

  3. Now, "( C:\Program Files (x86)\CodeBlocks\MinGW )"

See Video : https://youtu.be/Tb1VnXs60Lg

Changing permissions via chmod at runtime errors with "Operation not permitted"

$ sudo chmod ...

You need to either be the owner of the file or be the superuser, i.e., user root. If you own the directory but not the file, you can copy the file, rm the original, then mv it back, and then you will be able to chown it.

The easy way to temporarily be root is to run the command via sudo. ($ man 8 sudo)

How do I get the RootViewController from a pushed controller?

Use the viewControllers property of the UINavigationController. Example code:

// Inside another ViewController
NSArray *viewControllers = self.navigationController.viewControllers;
UIViewController *rootViewController = [viewControllers objectAtIndex:viewControllers.count - 2];

This is the standard way of getting the "back" view controller. The reason objectAtIndex:0 works is because the view controller you're trying to access is also the root one, if you were deeper in the navigation, the back view would not be the same as the root view.

to_string is not a member of std, says g++ (mingw)

to_string() is only present in c++11 so if c++ version is less use some alternate methods such as sprintf or ostringstream

How can I loop through all rows of a table? (MySQL)

CURSORS are an option here, but generally frowned upon as they often do not make best use of the query engine. Consider investigating 'SET Based Queries' to see if you can achieve what it is you want to do without using a CURSOR.

Different ways of adding to Dictionary

Dictionary.Add(key, value) and Dictionary[key] = value have different purposes:

  • Use the Add method to add new key/value pair, existing keys will not be replaced (an ArgumentException is thrown).
  • Use the indexer if you don't care whether the key already exists in the dictionary, in other words: add the key/value pair if the the key is not in the dictionary or replace the value for the specified key if the key is already in the dictionary.

NoSql vs Relational database

From mongodb.com:

NoSQL databases differ from older, relational technology in four main areas:

Data models: A NoSQL database lets you build an application without having to define the schema first unlike relational databases which make you define your schema before you can add any data to the system. No predefined schema makes NoSQL databases much easier to update as your data and requirements change.

Data structure: Relational databases were built in an era where data was fairly structured and clearly defined by their relationships. NoSQL databases are designed to handle unstructured data (e.g., texts, social media posts, video, email) which makes up much of the data that exists today.

Scaling: It’s much cheaper to scale a NoSQL database than a relational database because you can add capacity by scaling out over cheap, commodity servers. Relational databases, on the other hand, require a single server to host your entire database. To scale, you need to buy a bigger, more expensive server.

Development model: NoSQL databases are open source whereas relational databases typically are closed source with licensing fees baked into the use of their software. With NoSQL, you can get started on a project without any heavy investments in software fees upfront.

PostgreSQL: FOREIGN KEY/ON DELETE CASCADE

A foreign key with a cascade delete means that if a record in the parent table is deleted, then the corresponding records in the child table will automatically be deleted. This is called a cascade delete.

You are saying in a opposite way, this is not that when you delete from child table then records will be deleted from parent table.

UPDATE 1:

ON DELETE CASCADE option is to specify whether you want rows deleted in a child table when corresponding rows are deleted in the parent table. If you do not specify cascading deletes, the default behaviour of the database server prevents you from deleting data in a table if other tables reference it.

If you specify this option, later when you delete a row in the parent table, the database server also deletes any rows associated with that row (foreign keys) in a child table. The principal advantage to the cascading-deletes feature is that it allows you to reduce the quantity of SQL statements you need to perform delete actions.

So it's all about what will happen when you delete rows from Parent table not from child table.

So in your case when user removes entries from CATs table then rows will be deleted from books table. :)

Hope this helps you :)

@Cacheable key on multiple method arguments

You can use a Spring-EL expression, for eg on JDK 1.7:

@Cacheable(value="bookCache", key="T(java.util.Objects).hash(#p0,#p1, #p2)")

Truncate string in Laravel blade templates

Laravel 6 Update:

@php
$value = 'Artificial Intelligence';
$var = Str::limit($value, $limit = 15, $end = '');
print_r($var);
@endphp

<p class="card-text">{{ Illuminate\Support\Str::limit($value, 7) }}</p>
<h2 class="main-head">{!! Str::limit($value, 5) !!}</h2>

Generate random colors (RGB)

A neat way to generate RGB triplets within the 256 (aka 8-byte) range is

color = list(np.random.choice(range(256), size=3))

color is now a list of size 3 with values in the range 0-255. You can save it in a list to record if the color has been generated before or no.

Convert string to datetime in vb.net

Pass the decode pattern to ParseExact

Dim d as string = "201210120956"
Dim dt = DateTime.ParseExact(d, "yyyyMMddhhmm", Nothing)

ParseExact is available only from Net FrameWork 2.0.
If you are still on 1.1 you could use Parse, but you need to provide the IFormatProvider adequate to your string

HTML-5 date field shows as "mm/dd/yyyy" in Chrome, even when valid date is set

I have same problem and i found solution which is given below with full datepicker using simple HTML,Javascript and CSS. In this code i prepare formate like dd/mm/yyyy but you can work any.

HTML Code:

    <body>
<input type="date" id="dt" onchange="mydate1();" hidden/>
<input type="text" id="ndt"  onclick="mydate();" hidden />
<input type="button" Value="Date" onclick="mydate();" />
</body>

CSS Code:

#dt{text-indent: -500px;height:25px; width:200px;}

Javascript Code :

function mydate()
{
  //alert("");
document.getElementById("dt").hidden=false;
document.getElementById("ndt").hidden=true;
}
function mydate1()
{
 d=new Date(document.getElementById("dt").value);
dt=d.getDate();
mn=d.getMonth();
mn++;
yy=d.getFullYear();
document.getElementById("ndt").value=dt+"/"+mn+"/"+yy
document.getElementById("ndt").hidden=false;
document.getElementById("dt").hidden=true;
}

Output:

enter image description here

How do you run multiple programs in parallel from a bash script?

With bashj ( https://sourceforge.net/projects/bashj/ ) , you should be able to run not only multiple processes (the way others suggested) but also multiple Threads in one JVM controlled from your script. But of course this requires a java JDK. Threads consume less resource than processes.

Here is a working code:

#!/usr/bin/bashj

#!java

public static int cnt=0;

private static void loop() {u.p("java says cnt= "+(cnt++));u.sleep(1.0);}

public static void startThread()
{(new Thread(() ->  {while (true) {loop();}})).start();}

#!bashj

j.startThread()

while [ j.cnt -lt 4 ]
do
  echo "bash views cnt=" j.cnt
  sleep 0.5
done

Timing a command's execution in PowerShell

Just a word on drawing (incorrect) conclusions from any of the performance measurement commands referred to in the answers. There are a number of pitfalls that should taken in consideration aside from looking to the bare invocation time of a (custom) function or command.

Sjoemelsoftware

'Sjoemelsoftware' voted Dutch word of the year 2015
Sjoemelen means cheating, and the word sjoemelsoftware came into being due to the Volkswagen emissions scandal. The official definition is "software used to influence test results".

Personally, I think that "Sjoemelsoftware" is not always deliberately created to cheat test results but might originate from accommodating practical situation that are similar to test cases as shown below.

As an example, using the listed performance measurement commands, Language Integrated Query (LINQ)(1), is often qualified as the fasted way to get something done and it often is, but certainly not always! Anybody who measures a speed increase of a factor 40 or more in comparison with native PowerShell commands, is probably incorrectly measuring or drawing an incorrect conclusion.

The point is that some .Net classes (like LINQ) using a lazy evaluation (also referred to as deferred execution(2)). Meaning that when assign an expression to a variable, it almost immediately appears to be done but in fact it didn't process anything yet!

Let presume that you dot-source your . .\Dosomething.ps1 command which has either a PowerShell or a more sophisticated Linq expression (for the ease of explanation, I have directly embedded the expressions directly into the Measure-Command):

$Data = @(1..100000).ForEach{[PSCustomObject]@{Index=$_;Property=(Get-Random)}}

(Measure-Command {
    $PowerShell = $Data.Where{$_.Index -eq 12345}
}).totalmilliseconds
864.5237

(Measure-Command {
    $Linq = [Linq.Enumerable]::Where($Data, [Func[object,bool]] { param($Item); Return $Item.Index -eq 12345})
}).totalmilliseconds
24.5949

The result appears obvious, the later Linq command is a about 40 times faster than the first PowerShell command. Unfortunately, it is not that simple...

Let's display the results:

PS C:\> $PowerShell

Index  Property
-----  --------
12345 104123841

PS C:\> $Linq

Index  Property
-----  --------
12345 104123841

As expected, the results are the same but if you have paid close attention, you will have noticed that it took a lot longer to display the $Linq results then the $PowerShell results.
Let's specifically measure that by just retrieving a property of the resulted object:

PS C:\> (Measure-Command {$PowerShell.Property}).totalmilliseconds
14.8798
PS C:\> (Measure-Command {$Linq.Property}).totalmilliseconds
1360.9435

It took about a factor 90 longer to retrieve a property of the $Linq object then the $PowerShell object and that was just a single object!

Also notice an other pitfall that if you do it again, certain steps might appear a lot faster then before, this is because some of the expressions have been cached.

Bottom line, if you want to compare the performance between two functions, you will need to implement them in your used case, start with a fresh PowerShell session and base your conclusion on the actual performance of the complete solution.

(1) For more background and examples on PowerShell and LINQ, I recommend tihis site: High Performance PowerShell with LINQ
(2) I think there is a minor difference between the two concepts as with lazy evaluation the result is calculated when needed as apposed to deferred execution were the result is calculated when the system is idle

How to unpack an .asar file?

https://www.electronjs.org/apps/asarui

UI for Asar, Extract All, or drag extract file/directory

How do I get AWS_ACCESS_KEY_ID for Amazon?

Amit's answer tells you how to get your AWS_ACCESS_KEY_ID, but the Your Security Credentials page won't reveal your AWS_SECRET_ACCESS_KEY. As this blog points out:

Secret access keys are, as the name implies, secrets, like your password. Just as AWS doesn’t reveal your password back to you if you forgot it (you’d have to set a new password), the new security credentials page does not allowing retrieval of a secret access key after its initial creation. You should securely store your secret access keys as a security best practice, but you can always generate new access keys at any time.

So if you don't remember your AWS_SECRET_ACCESS_KEY, the blog goes on to tell how to create a new one:

  1. Create a new access key:

enter image description here

  1. "Download the .csv key file, which contains the access key ID and secret access key.":

enter image description here

As for your other questions:

  • I'm not sure about MERCHANT_ID and MARKETPLACE_ID.
  • I believe your sandbox question was addressed by Amit's point that you can play with AWS for a year without paying.

Capturing standard out and error with Start-Process

IMPORTANT:

We have been using the function as provided above by LPG.

However, this contains a bug you might encounter when you start a process that generates a lot of output. Due to this you might end up with a deadlock when using this function. Instead use the adapted version below:

Function Execute-Command ($commandTitle, $commandPath, $commandArguments)
{
  Try {
    $pinfo = New-Object System.Diagnostics.ProcessStartInfo
    $pinfo.FileName = $commandPath
    $pinfo.RedirectStandardError = $true
    $pinfo.RedirectStandardOutput = $true
    $pinfo.UseShellExecute = $false
    $pinfo.Arguments = $commandArguments
    $p = New-Object System.Diagnostics.Process
    $p.StartInfo = $pinfo
    $p.Start() | Out-Null
    [pscustomobject]@{
        commandTitle = $commandTitle
        stdout = $p.StandardOutput.ReadToEnd()
        stderr = $p.StandardError.ReadToEnd()
        ExitCode = $p.ExitCode
    }
    $p.WaitForExit()
  }
  Catch {
     exit
  }
}

Further information on this issue can be found at MSDN:

A deadlock condition can result if the parent process calls p.WaitForExit before p.StandardError.ReadToEnd and the child process writes enough text to fill the redirected stream. The parent process would wait indefinitely for the child process to exit. The child process would wait indefinitely for the parent to read from the full StandardError stream.

How To Set Up GUI On Amazon EC2 Ubuntu server

For LXDE/Lubuntu


1. connect to your instance (local forwarding port 5901)

ssh -L 5901:localhost:5901 -i "xxx.pem" [email protected]

2. Install packages

sudo apt update && sudo apt upgrade
sudo apt-get install xorg lxde vnc4server lubuntu-desktop

3. Create /etc/lightdm/lightdm.conf

sudo nano /etc/lightdm/lightdm.conf

4. Copy and paste the following into the lightdm.conf and save

[SeatDefaults]
allow-guest=false
user-session=LXDE
#user-session=Lubuntu

5. setup vncserver (you will be asked to create a password for the vncserver)

vncserver
sudo echo "lxpanel & /usr/bin/lxsession -s LXDE &" >> ~/.vnc/xstartup

6. Restart your instance and reconnect

sudo reboot
ssh -L 5901:localhost:5901 -i "xxx.pem" [email protected]

7. Start vncserver

vncserver -geometry 1280x800

8. In your Remote Desktop Client (e.g. Remmina) set Server to localhost:5901 and protocol to VNC

makefile:4: *** missing separator. Stop

Your version of Linux doesn't support this kind of functionality please go for another suitable version i.e. Kali Linux or Red Hat.

WAMP error: Forbidden You don't have permission to access /phpmyadmin/ on this server

Even I faced the same issue with my domain. If I gave an IP address it was working. But with a domain name it was not.

Then I checked my DNS A record. The domain had multiple entries with different IP addresses assigned. I removed all the wrong values, and it worked. Just one more check list if anyone faces a similar issue.

How to ftp with a batch file?

Use

ftp -s:FileName 

as decribed in Windows XP Professional Product Documentation.

The file name that you have to specify in place of FileName must contain FTP commands that you want to send to the server. Among theses commands are

  • open Computer [Port] to connect to an FTP server,
  • user UserName [Password] [Account] to authenticate with the FTP server,
  • get RemoteFile [LocalFile] to retrieve a file,
  • quit to end the FTP session and terminate the ftp program.

More commands can be found under Ftp subcommands.

Get Mouse Position

MouseInfo.getPointerInfo().getLocation() might be helpful. It returns a Point object corresponding to current mouse position.

How can I directly view blobs in MySQL Workbench

had the same problem, according to the MySQL documentation, you can select a Substring of a BLOB:

SELECT id, SUBSTRING(comment,1,2000) FROM t

HTH, glissi

What does the percentage sign mean in Python

Modulus operator; gives the remainder of the left value divided by the right value. Like:

3 % 1 would equal zero (since 3 divides evenly by 1)

3 % 2 would equal 1 (since dividing 3 by 2 results in a remainder of 1).

Angular2 - Input Field To Accept Only Numbers

Just Create a directive and add below hostlistener:

@HostListener('input', ['$event'])
    onInput(event: Event) {
        this.elementRef.nativeElement.value = (<HTMLInputElement>event.currentTarget).value.replace(/[^0-9]/g, '');
    }

Replace invalid text with empty. All keys and key combinations will now work across all browsers till IE9.

In C#, what is the difference between public, private, protected, and having no access modifier?

A graphical overview (summary in a nutshell)

Visibility

Since static classes are sealed, they cannot be inherited (except from Object), so the keyword protected is invalid on static classes.



For the defaults if you put no access modifier in front, see here:
Default visibility for C# classes and members (fields, methods, etc.)?

Non-nested

enum                              public
non-nested classes / structs      internal
interfaces                        internal
delegates in namespace            internal
class/struct member(s)            private
delegates nested in class/struct  private

Nested:

nested enum      public
nested interface public
nested class     private
nested struct    private

Also, there is the sealed-keyword, which makes a class not-inheritable.
Also, in VB.NET, the keywords are sometimes different, so here a cheat-sheet:

VB vs. CS equivalents

How to completely uninstall Visual Studio 2010?

This is the simplest way to remove all the packages. From an admin prompt:
wmic product where "name like 'microsoft visual%'" call uninstall /nointeractive

Repeat for SQL etc by replacing visual% in above command with sql.

Difference between malloc and calloc?

There's no difference in the size of the memory block allocated. calloc just fills the memory block with physical all-zero-bits pattern. In practice it is often assumed that the objects located in the memory block allocated with calloc have initilial value as if they were initialized with literal 0, i.e. integers should have value of 0, floating-point variables - value of 0.0, pointers - the appropriate null-pointer value, and so on.

From the pedantic point of view though, calloc (as well as memset(..., 0, ...)) is only guaranteed to properly initialize (with zeroes) objects of type unsigned char. Everything else is not guaranteed to be properly initialized and may contain so called trap representation, which causes undefined behavior. In other words, for any type other than unsigned char the aforementioned all-zero-bits patterm might represent an illegal value, trap representation.

Later, in one of the Technical Corrigenda to C99 standard, the behavior was defined for all integer types (which makes sense). I.e. formally, in the current C language you can initialize only integer types with calloc (and memset(..., 0, ...)). Using it to initialize anything else in general case leads to undefined behavior, from the point of view of C language.

In practice, calloc works, as we all know :), but whether you'd want to use it (considering the above) is up to you. I personally prefer to avoid it completely, use malloc instead and perform my own initialization.

Finally, another important detail is that calloc is required to calculate the final block size internally, by multiplying element size by number of elements. While doing that, calloc must watch for possible arithmetic overflow. It will result in unsuccessful allocation (null pointer) if the requested block size cannot be correctly calculated. Meanwhile, your malloc version makes no attempt to watch for overflow. It will allocate some "unpredictable" amount of memory in case overflow happens.

How to remove the last character from a string?

The described problem and proposed solutions sometimes relate to removing separators. If this is your case, then have a look at Apache Commons StringUtils, it has a method called removeEnd which is very elegant.

Example:

StringUtils.removeEnd("string 1|string 2|string 3|", "|");

Would result in: "string 1|string 2|string 3"

Handlebars/Mustache - Is there a built in way to loop through the properties of an object?

@Amit's answer is good because it will work in both Mustache and Handlebars.

As far as Handlebars-only solutions, I've seen a few and I like the each_with_key block helper at https://gist.github.com/1371586 the best.

  • It allows you to iterate over object literals without having to restructure them first, and
  • It gives you control over what you call the key variable. With many other solutions you have to be careful about using object keys named 'key', or 'property', etc.

How to order by with union in SQL?

In order to make the sort apply to only the first statement in the UNION, you can put it in a subselect with UNION ALL (both of these appear to be necessary in Oracle):

Select id,name,age FROM 
(    
 Select id,name,age
 From Student
 Where age < 15
 Order by name
)
UNION ALL
Select id,name,age
From Student
Where Name like "%a%"

Or (addressing Nicholas Carey's comment) you can guarantee the top SELECT is ordered and results appear above the bottom SELECT like this:

Select id,name,age, 1 as rowOrder
From Student
Where age < 15
UNION
Select id,name,age, 2 as rowOrder
From Student
Where Name like "%a%"
Order by rowOrder, name

Convert seconds into days, hours, minutes and seconds

With DateInterval :

$d1 = new DateTime();
$d2 = new DateTime();
$d2->add(new DateInterval('PT'.$timespan.'S'));

$interval = $d2->diff($d1);
echo $interval->format('%a days, %h hours, %i minutes and %s seconds');

// Or
echo sprintf('%d days, %d hours, %d minutes and %d seconds',
    $interval->days,
    $interval->h,
    $interval->i,
    $interval->s
);

// $interval->y => years
// $interval->m => months
// $interval->d => days
// $interval->h => hours
// $interval->i => minutes
// $interval->s => seconds
// $interval->days => total number of days

How to format a QString?

You can use QString.arg like this

QString my_formatted_string = QString("%1/%2-%3.txt").arg("~", "Tom", "Jane");
// You get "~/Tom-Jane.txt"

This method is preferred over sprintf because:

Changing the position of the string without having to change the ordering of substitution, e.g.

// To get "~/Jane-Tom.txt"
QString my_formatted_string = QString("%1/%3-%2.txt").arg("~", "Tom", "Jane");

Or, changing the type of the arguments doesn't require changing the format string, e.g.

// To get "~/Tom-1.txt"
QString my_formatted_string = QString("%1/%2-%3.txt").arg("~", "Tom", QString::number(1));

As you can see, the change is minimal. Of course, you generally do not need to care about the type that is passed into QString::arg() since most types are correctly overloaded.

One drawback though: QString::arg() doesn't handle std::string. You will need to call: QString::fromStdString() on your std::string to make it into a QString before passing it to QString::arg(). Try to separate the classes that use QString from the classes that use std::string. Or if you can, switch to QString altogether.

UPDATE: Examples are updated thanks to Frank Osterfeld.

UPDATE: Examples are updated thanks to alexisdm.

Is there a way to cast float as a decimal without rounding and preserving its precision?

cast (field1 as decimal(53,8)
) field 1

The default is: decimal(18,0)

How to increment datetime by custom months in python without using library

since no one suggested any solution, here is how i solved so far

year, month= divmod(mydate.month+1, 12)
if month == 0: 
      month = 12
      year = year -1
next_month = datetime.datetime(mydate.year + year, month, 1)

"insufficient memory for the Java Runtime Environment " message in eclipse

In your Eclipse installation directory you should be able to find the file eclipse.ini. Open it and find the -vmargs section. Adjust the value of:

-Xmx1024m

In this example it is set to 1GB.

How do I change UIView Size?

I know that there is already a solution to this question, but I found an alternative to this issue and maybe it could help someone.

I was having trouble with setting the frame of my sub view because certain values were referring to its position within the main view. So if you don't want to update your frame by changing the whole frame via CGRect, you can simply change a value of the frame and then update it.

// keep reference to you frames
var questionView = questionFrame.frame
var answerView = answerFrame.frame

// update the values of the copy        
questionView.size.height = CGFloat(screenSize.height * 0.70)
answerView.size.height = CGFloat(screenSize.height * 0.30)

// set the frames to the new frames
questionFrame.frame = questionView
answerFrame.frame = answerView

How do I center an anchor element in CSS?

write like this:

<div class="parent">
 <a href="http://www.example.com">example</a>
</div>

CSS

.parent{
  text-align:center
}

Detect Safari using jQuery

Apparently the only reliable and accepted solution would be to do feature detection like this:

browser_treats_urls_like_safari_does = false;
var last_location_hash = location.hash;
location.hash = '"blah"';
if (location.hash == '#%22blah%22')
    browser_treats_urls_like_safari_does = true;
location.hash = last_location_hash;

What are the most useful Intellij IDEA keyboard shortcuts?

This link has everything you need. Plus in Idea 8 atleast, every shortcut is completely customizable, so it's really up to you what the most useful ones are.

Idea 8 reference PDF

How do I schedule jobs in Jenkins?

By setting the schedule period to 15 13 * * * you tell Jenkins to schedule the build every day of every month of every year at the 15th minute of the 13th hour of the day.

Jenkins used a cron expression, and the different fields are:

  1. MINUTES Minutes in one hour (0-59)
  2. HOURS Hours in one day (0-23)
  3. DAYMONTH Day in a month (1-31)
  4. MONTH Month in a year (1-12)
  5. DAYWEEK Day of the week (0-7) where 0 and 7 are sunday

If you want to schedule your build every 5 minutes, this will do the job : */5 * * * *

If you want to schedule your build every day at 8h00, this will do the job : 0 8 * * *

For the past few versions (2014), Jenkins have a new parameter, H (extract from the Jenkins code documentation):

To allow periodically scheduled tasks to produce even load on the system, the symbol H (for “hash”) should be used wherever possible.

For example, using 0 0 * * * for a dozen daily jobs will cause a large spike at midnight. In contrast, using H H * * * would still execute each job once a day, but not all at the same time, better using limited resources.

Note also that:

The H symbol can be thought of as a random value over a range, but it actually is a hash of the job name, not a random function, so that the value remains stable for any given project.

More example of using 'H'

Change some value inside the List<T>

How about list.Find(x => x.Name == "height").Value = 20; This works fine. I know its an old post, but just wondered why hasn't anyone suggested this? Is there a drawback in this code?

Reading specific columns from a text file in python

You can use a zip function with a list comprehension :

with open('ex.txt') as f:
    print zip(*[line.split() for line in f])[1]

result :

('10', '20', '30', '40', '23', '13')

Django: Display Choice Value

Others have pointed out that a get_FOO_display method is what you need. I'm using this:

def get_type(self):
    return [i[1] for i in Item._meta.get_field('type').choices if i[0] == self.type][0]

which iterates over all of the choices that a particular item has until it finds the one that matches the items type

How to pipe list of files returned by find command to cat to view all the files

I use something like this:

find . -name <filename> -print0 | xargs -0 cat | grep <word2search4>

"-print0" argument for "find" and "-0" argument for "xargs" are needed to handle whitespace in file paths/names correctly.

Logging request/response messages when using HttpClient

The easiest solution would be to use Wireshark and trace the HTTP tcp flow.

How to add a response header on nginx when using proxy_pass?

There is a module called HttpHeadersMoreModule that gives you more control over headers. It does not come with Nginx and requires additional installation. With it, you can do something like this:

location ... {
  more_set_headers "Server: my_server";
}

That will "set the Server output header to the custom value for any status code and any content type". It will replace headers that are already set or add them if unset.

How do disable paging by swiping with finger in ViewPager but still be able to swipe programmatically?

Overriding only onTouchEvent and onInterceptTouchEvent is not sufficient in case you have ViewPager itself inside another ViewPager. Child ViewPager would steal horizontal scroll touch events from parent ViewPager unless it is positioned on its first / last page.

To make this setup work properly you need to override also the canScrollHorizontally method.

See LockableViewPager implementation below.

public class LockableViewPager extends ViewPager {

    private boolean swipeLocked;

    public LockableViewPager(Context context) {
        super(context);
    }

    public LockableViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public boolean getSwipeLocked() {
        return swipeLocked;
    }

    public void setSwipeLocked(boolean swipeLocked) {
        this.swipeLocked = swipeLocked;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return !swipeLocked && super.onTouchEvent(event);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        return !swipeLocked && super.onInterceptTouchEvent(event);
    }

    @Override
    public boolean canScrollHorizontally(int direction) {
        return !swipeLocked && super.canScrollHorizontally(direction);
    }

}

$(window).scrollTop() vs. $(document).scrollTop()

I've just had some of the similar problems with scrollTop described here.

In the end I got around this on Firefox and IE by using the selector $('*').scrollTop(0);

Not perfect if you have elements you don't want to effect but it gets around the Document, Body, HTML and Window disparity. If it helps...

What is the actual use of Class.forName("oracle.jdbc.driver.OracleDriver") while connecting to a database?

This command loads class of Oracle jdbc driver to be available for DriverManager instance. After the class is loaded system can connect to Oracle using it. As an alternative you can use registerDriver method of DriverManager and pass it with instance of JDBC driver you need.

Is a Python list guaranteed to have its elements stay in the order they are inserted in?

In short, yes, the order is preserved. In long:

In general the following definitions will always apply to objects like lists:

A list is a collection of elements that can contain duplicate elements and has a defined order that generally does not change unless explicitly made to do so. stacks and queues are both types of lists that provide specific (often limited) behavior for adding and removing elements (stacks being LIFO, queues being FIFO). Lists are practical representations of, well, lists of things. A string can be thought of as a list of characters, as the order is important ("abc" != "bca") and duplicates in the content of the string are certainly permitted ("aaa" can exist and != "a").

A set is a collection of elements that cannot contain duplicates and has a non-definite order that may or may not change over time. Sets do not represent lists of things so much as they describe the extent of a certain selection of things. The internal structure of set, how its elements are stored relative to each other, is usually not meant to convey useful information. In some implementations, sets are always internally sorted; in others the ordering is simply undefined (usually depending on a hash function).

Collection is a generic term referring to any object used to store a (usually variable) number of other objects. Both lists and sets are a type of collection. Tuples and Arrays are normally not considered to be collections. Some languages consider maps (containers that describe associations between different objects) to be a type of collection as well.

This naming scheme holds true for all programming languages that I know of, including Python, C++, Java, C#, and Lisp (in which lists not keeping their order would be particularly catastrophic). If anyone knows of any where this is not the case, please just say so and I'll edit my answer. Note that specific implementations may use other names for these objects, such as vector in C++ and flex in ALGOL 68 (both lists; flex is technically just a re-sizable array).

If there is any confusion left in your case due to the specifics of how the + sign works here, just know that order is important for lists and unless there is very good reason to believe otherwise you can pretty much always safely assume that list operations preserve order. In this case, the + sign behaves much like it does for strings (which are really just lists of characters anyway): it takes the content of a list and places it behind the content of another.

If we have

list1 = [0, 1, 2, 3, 4]
list2 = [5, 6, 7, 8, 9]

Then

list1 + list2

Is the same as

[0, 1, 2, 3, 4] + [5, 6, 7, 8, 9]

Which evaluates to

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Much like

"abdcde" + "fghijk"

Produces

"abdcdefghijk"

Android Color Picker

If you want a fragment solution, I have made a fork of android-color-picker where DialogFragment is used and is re-created on configuration change. Here's the link: https://github.com/lomza/android-color-picker

Concat a string to SELECT * MySql

If you want to concatenate the fields using / as a separator, you can use concat_ws:

select concat_ws('/', col1, col2, col3) from mytable

You cannot escape listing the columns in the query though. The *-syntax works only in "select * from". You can list the columns and construct the query dynamically though.

jquery $(this).id return Undefined

$(this) and this aren't the same. The first represents a jQuery object wrapped around your element. The second is just your element. The id property exists on the element, but not the jQuery object. As such, you have a few options:

  1. Access the property on the element directly:

    this.id

  2. Access it from the jQuery object:

    $(this).attr("id")

  3. Pull the object out of jQuery:

    $(this).get(0).id; // Or $(this)[0].id

  4. Get the id from the event object:

    When events are raised, for instance a click event, they carry important information and references around with them. In your code above, you have a click event. This event object has a reference to two items: currentTarget and target.

    Using target, you can get the id of the element that raised the event. currentTarget would simply tell you which element the event is currently bubbling through. These are not always the same.

    $("#button").on("click", function(e){ console.log( e.target.id ) });

Of all of these, the best option is to just access it directly from this itself, unless you're engaged in a series of nested events, then it might be best to use the event object of each nested event (give them all unique names) to reference elements in higher or lower scopes.

Merging 2 branches together in GIT

merge is used to bring two (or more) branches together.

a little example:

# on branch A:
# create new branch B
$ git checkout -b B
# hack hack
$ git commit -am "commit on branch B"

# create new branch C from A
$ git checkout -b C A
# hack hack
$ git commit -am "commit on branch C"

# go back to branch A
$ git checkout A
# hack hack
$ git commit -am "commit on branch A"

so now there are three separate branches (namely A B and C) with different heads

to get the changes from B and C back to A, checkout A (already done in this example) and then use the merge command:

# create an octopus merge
$ git merge B C

your history will then look something like this:

…-o-o-x-------A
      |\     /|
      | B---/ |
       \     /
        C---/

if you want to merge across repository/computer borders, have a look at git pull command, e.g. from the pc with branch A (this example will create two new commits):

# pull branch B
$ git pull ssh://host/… B
# pull branch C
$ git pull ssh://host/… C

Android getting value from selected radiobutton

In case, if you want to do some job on the selection of one of the radio buttons (without having any additional OK button or something), your code is fine, updated little.

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        RadioGroup rg = (RadioGroup) findViewById(R.id.radioGroup1);

        rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() 
        {
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch(checkedId){
                    case R.id.radio0:
                        // do operations specific to this selection
                        break;
                    case R.id.radio1:
                        // do operations specific to this selection
                        break;
                    case R.id.radio2:
                        // do operations specific to this selection
                        break;
                }   
            }
        });
    }
}

Parsing boolean values with argparse

As an improvement to @Akash Desarda 's answer, you could do

import argparse
from distutils.util import strtobool

parser = argparse.ArgumentParser()
parser.add_argument("--foo", 
    type=lambda x:bool(strtobool(x)),
    nargs='?', const=True, default=False)
args = parser.parse_args()
print(args.foo)

And it supports python test.py --foo

(base) [costa@costa-pc code]$ python test.py
False
(base) [costa@costa-pc code]$ python test.py --foo 
True
(base) [costa@costa-pc code]$ python test.py --foo True
True
(base) [costa@costa-pc code]$ python test.py --foo False
False

load json into variable

_x000D_
_x000D_
var itens = null;_x000D_
$.getJSON("yourfile.json", function(data) {_x000D_
  itens = data;_x000D_
  itens.forEach(function(item) {_x000D_
    console.log(item);_x000D_
  });_x000D_
});_x000D_
console.log(itens);
_x000D_
<html>_x000D_
<head>_x000D_
<script type="text/javascript" src="http://code.jquery.com/jquery-1.7.2.min.js"></script>_x000D_
</head>_x000D_
<body>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Adding a background image to a <div> element

Use like ..

<div style="background-image: url(../images/test-background.gif); height: 200px; width: 400px; border: 1px solid black;">Example of a DIV element with a background image:</div>
<div style="background-image: url(../images/test-background.gif); height: 200px; width: 400px; border: 1px solid black;"> </div>

Changing one character in a string

This code is not mine. I couldn't recall the site form where, I took it. Interestingly, you can use this to replace one character or more with one or more charectors. Though this reply is very late, novices like me (anytime) might find it useful.

Change Text function.

mytext = 'Hello Zorld'
mytext = mytext.replace('Z', 'W')
print mytext,

How to embed fonts in CSS?

I used Ataturk's font like this. I didn't use "TTF" version. I translated orginal font version ("otf" version) to "eot" and "woof" version. Then It works in local but not working when I uploaded the files to server. So I added "TTF" version too like this. Now, It's working on Chrome and Firefox but Internet Explorer still defence. When you installed on your computer "Ataturk" font, then working IE too. But I wanted to use this font without installing.

@font-face {
    font-family: 'Ataturk';
    font-style: normal;
    font-weight: normal;
    src: url('font/ataturk.eot');
    src: local('Ataturk Regular'), url('font/ataturk.ttf') format('truetype'), 
    url('font/ataturk.woff') format('woff');
}

You can see it on my website here: http://www.canotur.com

How do I compile and run a program in Java on my Mac?

Other solutions are good enough to answer your query. However, if you are looking for just one command to do that for you -

Create a file name "run", in directory where your Java files are. And save this in your file -

javac "$1.java"
if [ $? -eq 0 ]; then
  echo "--------Run output-------"
  java "$1"
fi

give this file run permission by running -

chmod 777 

Now you can run any of your files by merely running -

./run <yourfilename> (don't add .java in filename)

What is the difference between JDK and JRE?

The JRE is the Java Runtime Environment. It is a package of everything necessary to run a compiled Java program, including the Java Virtual Machine (JVM), the Java Class Library, the java command, and other infrastructure. However, it cannot be used to create new programs.

The JDK is the Java Development Kit, the full-featured SDK for Java. It has everything the JRE has, but also the compiler (javac) and tools (like javadoc and jdb). It is capable of creating and compiling programs.

Usually, if you only care about running Java programs on computer you will only install the JRE. It's all you need. On the other hand, if you are planning to do some Java programming, you need to install the JDK instead.

Sometimes, even if you are not planning to do any Java development on a computer, you still need the JDK installed. For example, if you are deploying a web application with JSP, you are technically just running Java programs inside the application server. Why would you need the JDK then? Because the application server will convert JSP into Java servlets and needs to use the JDK to compile the servlets. I am sure that there are more examples.

Declare multiple module.exports in Node.js

You can write a function that manually delegates between the other functions:

module.exports = function(arg) {
    if(arg instanceof String) {
         return doStringThing.apply(this, arguments);
    }else{
         return doObjectThing.apply(this, arguments);
    }
};

How to set environment variables from within package.json?

{
  ...
  "scripts": {
    "start": "ENV NODE_ENV=production someapp --options"
  }
  ...
}

VBA for filtering columns

Here's a different approach. The heart of it was created by turning on the Macro Recorder and filtering the columns per your specifications. Then there's a bit of code to copy the results. It will run faster than looping through each row and column:

Sub FilterAndCopy()
Dim LastRow As Long

Sheets("Sheet2").UsedRange.Offset(0).ClearContents
With Worksheets("Sheet1")
    .Range("$A:$E").AutoFilter
    .Range("$A:$E").AutoFilter field:=1, Criteria1:="#N/A"
    .Range("$A:$E").AutoFilter field:=2, Criteria1:="=String1", Operator:=xlOr, Criteria2:="=string2"
    .Range("$A:$E").AutoFilter field:=3, Criteria1:=">0"
    .Range("$A:$E").AutoFilter field:=5, Criteria1:="Number"
    LastRow = .Range("A" & .Rows.Count).End(xlUp).Row
    .Range("A1:A" & LastRow).SpecialCells(xlCellTypeVisible).EntireRow.Copy _
            Destination:=Sheets("Sheet2").Range("A1")
End With
End Sub

As a side note, your code has more loops and counter variables than necessary. You wouldn't need to loop through the columns, just through the rows. You'd then check the various cells of interest in that row, much like you did.

How to read a text file in project's root directory?

private string _filePath = Path.GetDirectoryName(System.AppDomain.CurrentDomain.BaseDirectory);

The method above will bring you something like this:

"C:\Users\myuser\Documents\Visual Studio 2015\Projects\myProjectNamespace\bin\Debug"

From here you can navigate backwards using System.IO.Directory.GetParent:

_filePath = Directory.GetParent(_filePath).FullName;

1 time will get you to \bin, 2 times will get you to \myProjectNamespace, so it would be like this:

_filePath = Directory.GetParent(Directory.GetParent(_filePath).FullName).FullName;

Well, now you have something like "C:\Users\myuser\Documents\Visual Studio 2015\Projects\myProjectNamespace", so just attach the final path to your fileName, for example:

_filePath += @"\myfile.txt";
TextReader tr = new StreamReader(_filePath);

Hope it helps.

CSV with comma or semicolon?

Initially it was to be a comma, however as the comma is often used as a decimal point it wouldnt be such good separator, hence others like the semicolon, mostly country dependant

http://en.wikipedia.org/wiki/Comma-separated_values#Lack_of_a_standard

add class with JavaScript

In your snippet, button is an instance of NodeList, to which you can't attach an event listener directly, nor can you change the elements' className properties directly.
Your best bet is to delegate the event:

document.body.addEventListener('mouseover',function(e)
{
    e = e || window.event;
    var target = e.target || e.srcElement;
    if (target.tagName.toLowerCase() === 'img' && target.className.match(/\bnavButton\b/))
    {
        target.className += ' active';//set class
    }
},false);

Of course, my guess is that the active class needs to be removed once the mouseout event fires, you might consider using a second delegator for that, but you could just aswell attach an event handler to the one element that has the active class:

document.body.addEventListener('mouseover',function(e)
{
    e = e || window.event;
    var oldSrc, target = e.target || e.srcElement;
    if (target.tagName.toLowerCase() === 'img' && target.className.match(/\bnavButton\b/))
    {
        target.className += ' active';//set class
        oldSrc = target.getAttribute('src');
        target.setAttribute('src', 'images/arrows/top_o.png');
        target.onmouseout = function()
        {
            target.onmouseout = null;//remove this event handler, we don't need it anymore
            target.className = target.className.replace(/\bactive\b/,'').trim();
            target.setAttribute('src', oldSrc);
        };
    }
},false);

There is some room for improvements, with this code, but I'm not going to have all the fun here ;-).

Check the fiddle here

How to make java delay for a few seconds?

A couple problems, you aren't delaying by much (.sleep is milliseconds, not seconds), and you're attempting to print in your catch statement. Your code should look more like:

if (i==1) {
    try {
        System.out.println("Scanning...");
        Thread.sleep(1000); // 1 second
    } catch (InterruptedException ex) {
        // handle error
    }
}

How does cookie based authentication work?

I realize this is years late, but I thought I could expand on Conor's answer and add a little bit more to the discussion.

Can someone give me a step by step description of how cookie based authentication works? I've never done anything involving either authentication or cookies. What does the browser need to do? What does the server need to do? In what order? How do we keep things secure?

Step 1: Client > Signing up

Before anything else, the user has to sign up. The client posts a HTTP request to the server containing his/her username and password.

Step 2: Server > Handling sign up

The server receives this request and hashes the password before storing the username and password in your database. This way, if someone gains access to your database they won't see your users' actual passwords.

Step 3: Client > User login

Now your user logs in. He/she provides their username/password and again, this is posted as a HTTP request to the server.

Step 4: Server > Validating login

The server looks up the username in the database, hashes the supplied login password, and compares it to the previously hashed password in the database. If it doesn't check out, we may deny them access by sending a 401 status code and ending the request.

Step 5: Server > Generating access token

If everything checks out, we're going to create an access token, which uniquely identifies the user's session. Still in the server, we do two things with the access token:

  1. Store it in the database associated with that user
  2. Attach it to a response cookie to be returned to the client. Be sure to set an expiration date/time to limit the user's session

Henceforth, the cookies will be attached to every request (and response) made between the client and server.

Step 6: Client > Making page requests

Back on the client side, we are now logged in. Every time the client makes a request for a page that requires authorization (i.e. they need to be logged in), the server obtains the access token from the cookie and checks it against the one in the database associated with that user. If it checks out, access is granted.

This should get you started. Be sure to clear the cookies upon logout!

How to stretch the background image to fill a div

body{
  margin:0;
  background:url('image.png') no-repeat 50% 50% fixed;
  background-size: cover;
}

How to open a file for both reading and writing?

Here's how you read a file, and then write to it (overwriting any existing data), without closing and reopening:

with open(filename, "r+") as f:
    data = f.read()
    f.seek(0)
    f.write(output)
    f.truncate()

Write string to output stream

You can create a PrintStream wrapping around your OutputStream and then just call it's print(String):

final OutputStream os = new FileOutputStream("/tmp/out");
final PrintStream printStream = new PrintStream(os);
printStream.print("String");
printStream.close();

Multiple aggregate functions in HAVING clause

There is no need to do two checks, why not just check for count = 3:

GROUP BY meetingID
HAVING COUNT(caseID) = 3

If you want to use the multiple checks, then you can use:

GROUP BY meetingID
HAVING COUNT(caseID) > 2
 AND COUNT(caseID) < 4

Python way to clone a git repository

Pretty simple method is to just pass the creds in the url, can be slightly suspect though - use with caution.

import os

def getRepo(repo_url, login_object):
  '''
  Clones the passed repo to my staging dir
  '''

  path_append = r"stage\repo" # Can set this as an arg 
  os.chdir(path_append)

  repo_moddedURL = 'https://' + login_object['username'] + ':' + login_object['password'] + '@github.com/UserName/RepoName.git'
  os.system('git clone '+ repo_moddedURL)

  print('Cloned!')


if __name__ == '__main__':
    getRepo('https://github.com/UserName/RepoYouWant.git', {'username': 'userName', 'password': 'passWord'})

How can I set the opacity or transparency of a Panel in WinForms?

As far as I know a Panel can have a transparent color only, you can not control the opacity of the panel. So, you can have some parts of a panel completely transparent but not a 50% to say something.

To use transparency you must define the transparent color property.

What is apache's maximum url length?

The official length according to the offical Apache docs is 8,192, but many folks have run into trouble at ~4,000.

MS Internet Explorer is usually the limiting factor anyway, as it caps the maximum URL size at 2,048.

Add JavaScript object to JavaScript object

var jsonIssues = [
 {ID:'1',Name:'Some name',Notes:'NOTES'},
 {ID:'2',Name:'Some name 2',Notes:'NOTES 2'}
];

If you want to add to the array then you can do this

jsonIssues[jsonIssues.length] = {ID:'3',Name:'Some name 3',Notes:'NOTES 3'};

Or you can use the push technique that the other guy posted, which is also good.

nginx upload client_max_body_size issue

From the documentation:

It is necessary to keep in mind that the browsers do not know how to correctly show this error.

I suspect this is what's happening, if you inspect the HTTP to-and-fro using tools such as Firebug or Live HTTP Headers (both Firefox extensions) you'll be able to see what's really going on.

How do I get started with Node.js

You can follow these tutorials to get started

Tutorials

Developer Sites

Videos

Screencasts

Books

Courses

Blogs

Podcasts

JavaScript resources

Node.js Modules

Other

AngularJs directive not updating another directive's scope

Just wondering why you are using 2 directives?

It seems like, in this case it would be more straightforward to have a controller as the parent - handle adding the data from your service to its $scope, and pass the model you need from there into your warrantyDirective.

Or for that matter, you could use 0 directives to achieve the same result. (ie. move all functionality out of the separate directives and into a single controller).

It doesn't look like you're doing any explicit DOM transformation here, so in this case, perhaps using 2 directives is overcomplicating things.

Alternatively, have a look at the Angular documentation for directives: http://docs.angularjs.org/guide/directive The very last example at the bottom of the page explains how to wire up dependent directives.

How can I find WPF controls by name or type?

This code just fixes @CrimsonX answer's bug:

 public static T FindChild<T>(DependencyObject parent, string childName)
       where T : DependencyObject
    {    
      // Confirm parent and childName are valid. 
      if (parent == null) return null;

      T foundChild = null;

      int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
      for (int i = 0; i < childrenCount; i++)
      {
        var child = VisualTreeHelper.GetChild(parent, i);
        // If the child is not of the request child type child
        T childType = child as T;
        if (childType == null)
        {
          // recursively drill down the tree
          foundChild = FindChild<T>(child, childName);

          // If the child is found, break so we do not overwrite the found child. 
          if (foundChild != null) break;
        }
        else if (!string.IsNullOrEmpty(childName))
        {
          var frameworkElement = child as FrameworkElement;
          // If the child's name is set for search
          if (frameworkElement != null && frameworkElement.Name == childName)
          {
            // if the child's name is of the request name
            foundChild = (T)child;
            break;
          }

 // recursively drill down the tree
          foundChild = FindChild<T>(child, childName);

          // If the child is found, break so we do not overwrite the found child. 
          if (foundChild != null) break;


        else
        {
          // child element found.
          foundChild = (T)child;
          break;
        }
      }

      return foundChild;
    }  

You just need to continue calling the method recursively if types are matching but names don't (this happens when you pass FrameworkElement as T). otherwise it's gonna return null and that's wrong.

Redirect parent window from an iframe action

This will solve the misery.

<script>parent.location='http://google.com';</script>

How do I draw a shadow under a UIView?

All Answer all well but I want to add one more point

If you encounter a problem when you have table cells, Deque a new cell there is a mismatch in shadow so in this case, you need to place your shadow code in a layoutSubviews method so that it will behave nicely in all conditions.

-(void)layoutSubviews{
    [super layoutSubviews];

    [self.contentView setNeedsLayout];
    [self.contentView layoutIfNeeded];
    [VPShadow applyShadowView:self];
}

or in ViewControllers for specific view place shadow code inside the following method so that it's work well

-(void)viewDidLayoutSubviews{
    [super viewDidLayoutSubviews];

    [self.viewShadow layoutIfNeeded];
    [VPShadow applyShadowView:self.viewShadow];
}

I have modified my shadow implementation for new devs for more generalized form ex:

/*!
 @brief Add shadow to a view.

 @param layer CALayer of the view.

 */
+(void)applyShadowOnView:(CALayer *)layer OffsetX:(CGFloat)x OffsetY:(CGFloat)y blur:(CGFloat)radius opacity:(CGFloat)alpha RoundingCorners:(CGFloat)cornerRadius{
    UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRoundedRect:layer.bounds cornerRadius:cornerRadius];
    layer.masksToBounds = NO;
    layer.shadowColor = [UIColor blackColor].CGColor;
    layer.shadowOffset = CGSizeMake(x,y);// shadow x and y
    layer.shadowOpacity = alpha;
    layer.shadowRadius = radius;// blur effect
    layer.shadowPath = shadowPath.CGPath;
}

XML element with attribute and content using JAXB

Updated Solution - using the schema solution that we were debating. This gets you to your answer:

Sample Schema:

<?xml version="1.0" encoding="UTF-8"?>
<schema xmlns="http://www.w3.org/2001/XMLSchema" 
targetNamespace="http://www.example.org/Sport"
xmlns:tns="http://www.example.org/Sport" 
elementFormDefault="qualified"
xmlns:jaxb="http://java.sun.com/xml/ns/jaxb" 
jaxb:version="2.0">

<complexType name="sportType">
    <attribute name="type" type="string" />
    <attribute name="gender" type="string" />
</complexType>

<element name="sports">
    <complexType>
        <sequence>
            <element name="sport" minOccurs="0" maxOccurs="unbounded"
                type="tns:sportType" />
        </sequence>
    </complexType>
</element>

Code Generated

SportType:

package org.example.sport; 

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlType;


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "sportType")
public class SportType {

    @XmlAttribute
    protected String type;
    @XmlAttribute
    protected String gender;

    public String getType() {
        return type;
    }


    public void setType(String value) {
        this.type = value;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String value) {
        this.gender = value;
    }

}

Sports:

package org.example.sport;

import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;


@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
        "sport"
})
@XmlRootElement(name = "sports")
public class Sports {

    protected List<SportType> sport;

    public List<SportType> getSport() {
        if (sport == null) {
            sport = new ArrayList<SportType>();
        }
        return this.sport;
    }

}

Output class files are produced by running xjc against the schema on the command line

Is it possible to set UIView border properties from interface builder?

Similar answer to iHulk's one, but in Swift

Add a file named UIView.swift in your project (or just paste this in any file) :

import UIKit

@IBDesignable extension UIView {
    @IBInspectable var borderColor: UIColor? {
        set {
            layer.borderColor = newValue?.cgColor
        }
        get {
            guard let color = layer.borderColor else {
                return nil
            }
            return UIColor(cgColor: color)
        }
    }
    @IBInspectable var borderWidth: CGFloat {
        set {
            layer.borderWidth = newValue
        }
        get {
            return layer.borderWidth
        }
    }
    @IBInspectable var cornerRadius: CGFloat {
        set {
            layer.cornerRadius = newValue
            clipsToBounds = newValue > 0
        }
        get {
            return layer.cornerRadius
        }
    }
}

Then this will be available in Interface Builder for every button, imageView, label, etc. in the Utilities Panel > Attributes Inspector :

Attributes Inspector

Note: the border will only appear at runtime.

How to submit http form using C#

I needed to have a button handler that created a form post to another application within the client's browser. I landed on this question but didn't see an answer that suited my scenario. This is what I came up with:

      protected void Button1_Click(object sender, EventArgs e)
        {

            var formPostText = @"<html><body><div>
<form method=""POST"" action=""OtherLogin.aspx"" name=""frm2Post"">
  <input type=""hidden"" name=""field1"" value=""" + TextBox1.Text + @""" /> 
  <input type=""hidden"" name=""field2"" value=""" + TextBox2.Text + @""" /> 
</form></div><script type=""text/javascript"">document.frm2Post.submit();</script></body></html>
";
            Response.Write(formPostText);
        }

C# Reflection: How to get class reference from string?

You can use Type.GetType(string), but you'll need to know the full class name including namespace, and if it's not in the current assembly or mscorlib you'll need the assembly name instead. (Ideally, use Assembly.GetType(typeName) instead - I find that easier in terms of getting the assembly reference right!)

For instance:

// "I know String is in the same assembly as Int32..."
Type stringType = typeof(int).Assembly.GetType("System.String");

// "It's in the current assembly"
Type myType = Type.GetType("MyNamespace.MyType");

// "It's in System.Windows.Forms.dll..."
Type formType = Type.GetType ("System.Windows.Forms.Form, " + 
    "System.Windows.Forms, Version=2.0.0.0, Culture=neutral, " + 
    "PublicKeyToken=b77a5c561934e089");

Removing duplicate elements from an array in Swift

Slightly more succinct syntax version of Daniel Krom's Swift 2 answer, using a trailing closure and shorthand argument name, which appears to be based on Airspeed Velocity's original answer:

func uniq<S: SequenceType, E: Hashable where E == S.Generator.Element>(source: S) -> [E] {
  var seen = [E: Bool]()
  return source.filter { seen.updateValue(true, forKey: $0) == nil }
}

Example of implementing a custom type that can be used with uniq(_:) (which must conform to Hashable, and thus Equatable, because Hashable extends Equatable):

func ==(lhs: SomeCustomType, rhs: SomeCustomType) -> Bool {
  return lhs.id == rhs.id // && lhs.someOtherEquatableProperty == rhs.someOtherEquatableProperty
}

struct SomeCustomType {

  let id: Int

  // ...

}

extension SomeCustomType: Hashable {

  var hashValue: Int {
    return id
  }

}

In the above code...

id, as used in the overload of ==, could be any Equatable type (or method that returns an Equatable type, e.g., someMethodThatReturnsAnEquatableType()). The commented-out code demonstrates extending the check for equality, where someOtherEquatableProperty is another property of an Equatable type (but could also be a method that returns an Equatable type).

id, as used in the hashValue computed property (required to conform to Hashable), could be any Hashable (and thus Equatable) property (or method that returns a Hashable type).

Example of using uniq(_:):

var someCustomTypes = [SomeCustomType(id: 1), SomeCustomType(id: 2), SomeCustomType(id: 3), SomeCustomType(id: 1)]

print(someCustomTypes.count) // 4

someCustomTypes = uniq(someCustomTypes)

print(someCustomTypes.count) // 3

SQL: capitalize first letter only

select replace(wm_concat(new),',','-') exp_res from (select distinct initcap(substr(name,decode(level,1,1,instr(name,'-',1,level-1)+1),decode(level,(length(name)-length(replace(name,'-','')))+1,9999,instr(name,'-',1,level)-1-decode(level,1,0,instr(name,'-',1,level-1))))) new from table;
connect by level<= (select (length(name)-length(replace(name,'-','')))+1 from table));

What does the term "Tuple" Mean in Relational Databases?

A tuple is used to define a slice of data from a cube; it is composed of an ordered collection of one member from one or more dimensions. A tuple is used to identify specific sections of multidimensional data from a cube; a tuple composed of one member from each dimension in a cube completely describes a cell value.

Can't push to the heroku

There has to be a .git directory in the root of your project.

If you don't see that directory run git init and then re-associate your remote.

Like so:

heroku git:remote -a herokuAppName
git push heroku master

bower command not found

Alternatively, you can use npx which comes along with the npm > 5.6.

npx bower install

How to disable gradle 'offline mode' in android studio?

On Windows:-

Go to File -> Settings.

And open the 'Build,Execution,Deployment'. Then open the

Build Tools -> Gradle

Then uncheck -> Offline work on the right.

Click the OK button.

Then Rebuild the Project.

On Mac OS:-

go to Android Studio -> Preferences, and the rest is the same. OR follow steps given in the image

[For Mac go 1

enter image description here

Create a zip file and download it

Add Content-length header describing size of zip file in bytes.

header("Content-type: application/zip"); 
header("Content-Disposition: attachment; filename=$archive_file_name");
header("Content-length: " . filesize($archive_file_name));
header("Pragma: no-cache"); 
header("Expires: 0"); 
readfile("$archive_file_name");

Also make sure that there is absolutely no white space before <? and after ?>. I see a space here:

?

 <?php
$file_names = array('iMUST Operating Manual V1.3a.pdf','iMUST Product Information Sheet.pdf');

External resource not being loaded by AngularJs

Whitelist the resource with $sceDelegateProvider

This is caused by a new security policy put in place in Angular 1.2. It makes XSS harder by preventing a hacker from dialling out (i.e. making a request to a foreign URL, potentially containing a payload).

To get around it properly you need to whitelist the domains you want to allow, like this:

angular.module('myApp',['ngSanitize']).config(function($sceDelegateProvider) {
  $sceDelegateProvider.resourceUrlWhitelist([
    // Allow same origin resource loads.
    'self',
    // Allow loading from our assets domain.  Notice the difference between * and **.
    'http://srv*.assets.example.com/**'
  ]);

  // The blacklist overrides the whitelist so the open redirect here is blocked.
  $sceDelegateProvider.resourceUrlBlacklist([
    'http://myapp.example.com/clickThru**'
  ]);
});

This example is lifted from the documentation which you can read here:

https://docs.angularjs.org/api/ng/provider/$sceDelegateProvider

Be sure to include ngSanitize in your app to make this work.

Disabling the feature

If you want to turn off this useful feature, and you're sure your data is secure, you can simply allow **, like so:

angular.module('app').config(function($sceDelegateProvider) {
  $sceDelegateProvider.resourceUrlWhitelist(['**']);
});

Window vs Page vs UserControl for WPF navigation?

  • Window is like Windows.Forms.Form, so just a new window
  • Page is, according to online documentation:

    Encapsulates a page of content that can be navigated to and hosted by Windows Internet Explorer, NavigationWindow, and Frame.

    So you basically use this if going you visualize some HTML content

  • UserControl is for cases when you want to create some reusable component (but not standalone one) to use it in multiple different Windows

Difference between abstract class and interface in Python

In general, interfaces are used only in languages that use the single-inheritance class model. In these single-inheritance languages, interfaces are typically used if any class could use a particular method or set of methods. Also in these single-inheritance languages, abstract classes are used to either have defined class variables in addition to none or more methods, or to exploit the single-inheritance model to limit the range of classes that could use a set of methods.

Languages that support the multiple-inheritance model tend to use only classes or abstract base classes and not interfaces. Since Python supports multiple inheritance, it does not use interfaces and you would want to use base classes or abstract base classes.

http://docs.python.org/library/abc.html

Check a collection size with JSTL

As suggested by @Joel and @Mark Chorley in earlier comments:

${empty companies}

This checks for null and empty lists/collections/arrays. It doesn't get you the length but it satisfies the example in the OP. If you can get away with it this is just cleaner than importing a tag library and its crusty syntax like gt.

Phone Number Validation MVC

Try for simple regular expression for Mobile No

[Required (ErrorMessage="Required")]
[RegularExpression(@"^(\d{10})$", ErrorMessage = "Wrong mobile")]
public string Mobile { get; set; }

Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

From the Server Manager's Features node, you can also remove some of the sub-items under the .NET Framework 3.5.1 Features that are installed by the activation of some of the other roles.

For instance, removed the WCF Activation Features as follows and our websites came back:

  • [x] .NET Framework 3.5.1 Features
    • [x] .NET Framework 3.5.1
    • [ ] WCF Activation
      • [ ] HTTP Activation
      • [ ] Non-HTTP Activation

Note: this did not require a restart for us.

Calling a function on bootstrap modal open

you can use show instead of shown for making the function to load just before modal open, instead of after modal open.

$('#code').on('show.bs.modal', function (e) {
  // do something...
})

Android: resizing imageview in XML

for example:

<ImageView android:id="@+id/image_view"     
  android:layout_width="wrap_content"  
  android:layout_height="wrap_content"  
  android:adjustViewBounds="true"  
  android:maxWidth="42dp"  
  android:maxHeight="42dp"  
  android:scaleType="fitCenter"  
  android:layout_marginLeft="3dp"  
  android:src="@drawable/icon"  
  /> 

Add property android:scaleType="fitCenter" and android:adjustViewBounds="true".

How to get day of the month?

LocalDate date = new Date(); date.lengthOfMonth()

or

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("YYYY-MM-dd");

DateTimeFormatter monthFormatter = DateTimeFormatter.ofPattern("MMM");

String stringDate = formatter.format(date);

String month = monthFormatter.format(date);

How to use global variable in node.js?

Most people advise against using global variables. If you want the same logger class in different modules you can do this

logger.js

  module.exports = new logger(customConfig);

foobar.js

  var logger = require('./logger');
  logger('barfoo');

If you do want a global variable you can do:

global.logger = new logger(customConfig);

Is it possible to Turn page programmatically in UIPageViewController?

Yes it is possible with the method:

- (void)setViewControllers:(NSArray *)viewControllers 
                 direction:(UIPageViewControllerNavigationDirection)direction 
                  animated:(BOOL)animated 
                completion:(void (^)(BOOL finished))completion;`

That is the same method used for setting up the first view controller on the page. Similar, you can use it to go to other pages.

Wonder why viewControllers is an array, and not a single view controller?

That's because a page view controller could have a "spine" (like in iBooks), displaying 2 pages of content at a time. If you display 1 page of content at a time, then just pass in a 1-element array.

An example in Swift:

pageContainer.setViewControllers([displayThisViewController], direction: .Forward, animated: true, completion: nil)

How can I create download link in HTML?

To link to the file, do the same as any other page link:

<a href="...">link text</a>

To force things to download even if they have an embedded plugin (Windows + QuickTime = ugh), you can use this in your htaccess / apache2.conf:

AddType application/octet-stream EXTENSION

How do I get the HTML code of a web page in PHP?

Also if you want to manipulate the retrieved page somehow, you might want to try some php DOM parser. I find PHP Simple HTML DOM Parser very easy to use.

Android emulator failed to allocate memory 8

This following solution worked for me. In the following configuration file:

C:\Users\<user>\.android\avd\<avd-profile-name>.avd\config.ini

Replace

hw.ramSize=1024

by

hw.ramSize=1024MB

How to get a date in YYYY-MM-DD format from a TSQL datetime field?

In case someone wants to do it the other way around and finds this.

select convert(datetime, '12.09.2014', 104)

This converts a string in the German date format to a datetime object.

Why 104? See here: http://msdn.microsoft.com/en-us/library/ms187928.aspx

anchor jumping by using javascript

You can get the coordinate of the target element and set the scroll position to it. But this is so complicated.

Here is a lazier way to do that:

function jump(h){
    var url = location.href;               //Save down the URL without hash.
    location.href = "#"+h;                 //Go to the target element.
    history.replaceState(null,null,url);   //Don't like hashes. Changing it back.
}

This uses replaceState to manipulate the url. If you also want support for IE, then you will have to do it the complicated way:

function jump(h){
    var top = document.getElementById(h).offsetTop; //Getting Y of target element
    window.scrollTo(0, top);                        //Go there directly or some transition
}?

Demo: http://jsfiddle.net/DerekL/rEpPA/
Another one w/ transition: http://jsfiddle.net/DerekL/x3edvp4t/

You can also use .scrollIntoView:

document.getElementById(h).scrollIntoView();   //Even IE6 supports this

(Well I lied. It's not complicated at all.)

Cannot authenticate into mongo, "auth fails"

This fixed my issue:

Go to terminal shell and type mongo.

Then type use db_name.

Then type:

 db.createUser(
   {
     user: "mongodb",
     pwd: "dogmeatsubparflavour1337",
     roles: [ { role: "dbOwner", db: "db_name" } ]
   }
 )

Also try: db.getUsers()

Quick sample:

const MongoClient = require('mongodb').MongoClient;

// MongoDB Connection Info
const url = 'mongodb://mongodb:[email protected]:27017/?authMechanism=DEFAULT&authSource=db_name';
// Additional options: https://docs.mongodb.com/manual/reference/connection-string/#connection-string-options

// Use Connect Method to connect to the Server
MongoClient.connect(url)
  .then((db) => {
    console.log(db);
    console.log('Casually connected correctly to server.');
    // Be careful with db.close() when working asynchronously
    db.close();
  })
  .catch((error) => {
    console.log(error);
  });

Installing pip packages to $HOME folder

While you can use a virtualenv, you don't need to. The trick is passing the PEP370 --user argument to the setup.py script. With the latest version of pip, one way to do it is:

pip install --user mercurial

This should result in the hg script being installed in $HOME/.local/bin/hg and the rest of the hg package in $HOME/.local/lib/pythonx.y/site-packages/.

Note, that the above is true for Python 2.6. There has been a bit of controversy among the Python core developers about what is the appropriate directory location on Mac OS X for PEP370-style user installations. In Python 2.7 and 3.2, the location on Mac OS X was changed from $HOME/.local to $HOME/Library/Python. This might change in a future release. But, for now, on 2.7 (and 3.2, if hg were supported on Python 3), the above locations will be $HOME/Library/Python/x.y/bin/hg and $HOME/Library/Python/x.y/lib/python/site-packages.

Check whether a value exists in JSON object

You could improve on the answer from Ponmudi VN:

  • Shorter Code
  • Look for a key and a value

See this fiddle: https://jsfiddle.net/solarbaypilot/sn3wtea2/

function _isContains(json, keyname, value) {

return Object.keys(json).some(key => {
        return typeof json[key] === 'object' ? 
        _isContains(json[key], keyname, value) : key === keyname && json[key] === value;
    });
}

var JSONObject = {"animals": [{name:"cat"}, {name:"dog"}]};


document.getElementById('dog').innerHTML = _isContains(JSONObject, "name", "dog");
document.getElementById('puppy').innerHTML = _isContains(JSONObject, "name", "puppy");

Get the IP address of the machine

As the question specifies Linux, my favourite technique for discovering the IP-addresses of a machine is to use netlink. By creating a netlink socket of the protocol NETLINK_ROUTE, and sending an RTM_GETADDR, your application will received a message(s) containing all available IP addresses. An example is provided here.

In order to simply parts of the message handling, libmnl is convenient. If you are curios in figuring out more about the different options of NETLINK_ROUTE (and how they are parsed), the best source is the source code of iproute2 (especially the monitor application) as well as the receive functions in the kernel. The man page of rtnetlink also contains useful information.

How to set the thumbnail image on HTML5 video?

Add poster="placeholder.png" to the video tag.

<video width="470" height="255" poster="placeholder.png" controls>
    <source src="video.mp4" type="video/mp4">
    <source src="video.ogg" type="video/ogg">
    <source src="video.webm" type="video/webm">
    <object data="video.mp4" width="470" height="255">
    <embed src="video.swf" width="470" height="255">
    </object>
</video>

Does that work?

How to open link in new tab on html?

If anyone is looking out for using it to apply on the react then you can follow the code pattern given below. You have to add extra property which is rel.

<a href="mysite.com" target="_blank" rel="noopener noreferrer" >Click me to open in new Window</a>

Reading file input from a multipart/form-data POST

The guy who solved this posted it as LGPL and you're not allowed to modify it. I didn't even click on it when I saw that. Here's my version. This needs to be tested. There are probably bugs. Please post any updates. No warranty. You can modify this all you want, call it your own, print it out on a piece of paper and use it for kennel scrap, ... don't care.

using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.Net;
using System.Text;
using System.Web;

namespace DigitalBoundaryGroup
{
    class HttpNameValueCollection
    {
        public class File
        {
            private string _fileName;
            public string FileName { get { return _fileName ?? (_fileName = ""); } set { _fileName = value; } }

            private string _fileData;
            public string FileData { get { return _fileData ?? (_fileName = ""); } set { _fileData = value; } }

            private string _contentType;
            public string ContentType { get { return _contentType ?? (_contentType = ""); } set { _contentType = value; } }
        }

        private NameValueCollection _post;
        private Dictionary<string, File> _files;
        private readonly HttpListenerContext _ctx;

        public NameValueCollection Post { get { return _post ?? (_post = new NameValueCollection()); } set { _post = value; } }
        public NameValueCollection Get { get { return _ctx.Request.QueryString; } }
        public Dictionary<string, File> Files { get { return _files ?? (_files = new Dictionary<string, File>()); } set { _files = value; } }

        private void PopulatePostMultiPart(string post_string)
        {
            var boundary_index = _ctx.Request.ContentType.IndexOf("boundary=") + 9;
            var boundary = _ctx.Request.ContentType.Substring(boundary_index, _ctx.Request.ContentType.Length - boundary_index);

            var upper_bound = post_string.Length - 4;

            if (post_string.Substring(2, boundary.Length) != boundary)
                throw (new InvalidDataException());

            var current_string = new StringBuilder();

            for (var x = 4 + boundary.Length; x < upper_bound; ++x)
            {
                if (post_string.Substring(x, boundary.Length) == boundary)
                {
                    x += boundary.Length + 1;

                    var post_variable_string = current_string.Remove(current_string.Length - 4, 4).ToString();

                    var end_of_header = post_variable_string.IndexOf("\r\n\r\n");

                    if (end_of_header == -1) throw (new InvalidDataException());

                    var filename_index = post_variable_string.IndexOf("filename=\"", 0, end_of_header);
                    var filename_starts = filename_index + 10;
                    var content_type_starts = post_variable_string.IndexOf("Content-Type: ", 0, end_of_header) + 14;
                    var name_starts = post_variable_string.IndexOf("name=\"") + 6;
                    var data_starts = end_of_header + 4;

                    if (filename_index != -1)
                    {
                        var filename = post_variable_string.Substring(filename_starts, post_variable_string.IndexOf("\"", filename_starts) - filename_starts);
                        var content_type = post_variable_string.Substring(content_type_starts, post_variable_string.IndexOf("\r\n", content_type_starts) - content_type_starts);
                        var file_data = post_variable_string.Substring(data_starts, post_variable_string.Length - data_starts);
                        var name = post_variable_string.Substring(name_starts, post_variable_string.IndexOf("\"", name_starts) - name_starts);
                        Files.Add(name, new File() { FileName = filename, ContentType = content_type, FileData = file_data });
                    }
                    else
                    {
                        var name = post_variable_string.Substring(name_starts, post_variable_string.IndexOf("\"", name_starts) - name_starts);
                        var value = post_variable_string.Substring(data_starts, post_variable_string.Length - data_starts);
                        Post.Add(name, value);
                    }

                    current_string.Clear();
                    continue;
                }

                current_string.Append(post_string[x]);
            }
        }

        private void PopulatePost()
        {
            if (_ctx.Request.HttpMethod != "POST" || _ctx.Request.ContentType == null) return;

            var post_string = new StreamReader(_ctx.Request.InputStream, _ctx.Request.ContentEncoding).ReadToEnd();

            if (_ctx.Request.ContentType.StartsWith("multipart/form-data"))
                PopulatePostMultiPart(post_string);
            else
                Post = HttpUtility.ParseQueryString(post_string);

        }

        public HttpNameValueCollection(ref HttpListenerContext ctx)
        {
            _ctx = ctx;
            PopulatePost();
        }


    }
}

How to read a text file?

It depends on what you are trying to do.

file, err := os.Open("file.txt")
fmt.print(file)

The reason it outputs &{0xc082016240}, is because you are printing the pointer value of a file-descriptor (*os.File), not file-content. To obtain file-content, you may READ from a file-descriptor.


To read all file content(in bytes) to memory, ioutil.ReadAll

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "log"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


  b, err := ioutil.ReadAll(file)
  fmt.Print(b)
}

But sometimes, if the file size is big, it might be more memory-efficient to just read in chunks: buffer-size, hence you could use the implementation of io.Reader.Read from *os.File

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


    buf := make([]byte, 32*1024) // define your buffer size here.

    for {
        n, err := file.Read(buf)

        if n > 0 {
            fmt.Print(buf[:n]) // your read buffer.
        }

        if err == io.EOF {
            break
        }
        if err != nil {
            log.Printf("read %d bytes: %v", n, err)
            break
        }
    }

}

Otherwise, you could also use the standard util package: bufio, try Scanner. A Scanner reads your file in tokens: separator.

By default, scanner advances the token by newline (of course you can customise how scanner should tokenise your file, learn from here the bufio test).

package main

import (
    "fmt"
    "os"
    "log"
    "bufio"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()

    scanner := bufio.NewScanner(file)

    for scanner.Scan() {             // internally, it advances token based on sperator
        fmt.Println(scanner.Text())  // token in unicode-char
        fmt.Println(scanner.Bytes()) // token in bytes

    }
}

Lastly, I would also like to reference you to this awesome site: go-lang file cheatsheet. It encompassed pretty much everything related to working with files in go-lang, hope you'll find it useful.

How can I reconcile detached HEAD with master/origin?

Just do this:

git checkout master

Or, if you have changes that you want to keep, do this:

git checkout -b temp
git checkout -B master temp

"pip install json" fails on Ubuntu

json is a built-in module, you don't need to install it with pip.

How do you specify table padding in CSS? ( table, not cell padding )

CSS doesn't really allow you to do this on a table level. Generally, I specify cellspacing="3" when I want to achieve this effect. Obviously not a css solution, so take it for what it's worth.

Spring Boot - inject map from application.yml

I run into the same problem today, but unfortunately Andy's solution didn't work for me. In Spring Boot 1.2.1.RELEASE it's even easier, but you have to be aware of a few things.

Here is the interesting part from my application.yml:

oauth:
  providers:
    google:
     api: org.scribe.builder.api.Google2Api
     key: api_key
     secret: api_secret
     callback: http://callback.your.host/oauth/google

providers map contains only one map entry, my goal is to provide dynamic configuration for other OAuth providers. I want to inject this map into a service that will initialize services based on the configuration provided in this yaml file. My initial implementation was:

@Service
@ConfigurationProperties(prefix = 'oauth')
class OAuth2ProvidersService implements InitializingBean {

    private Map<String, Map<String, String>> providers = [:]

    @Override
    void afterPropertiesSet() throws Exception {
       initialize()
    }

    private void initialize() {
       //....
    }
}

After starting the application, providers map in OAuth2ProvidersService was not initialized. I tried the solution suggested by Andy, but it didn't work as well. I use Groovy in that application, so I decided to remove private and let Groovy generates getter and setter. So my code looked like this:

@Service
@ConfigurationProperties(prefix = 'oauth')
class OAuth2ProvidersService implements InitializingBean {

    Map<String, Map<String, String>> providers = [:]

    @Override
    void afterPropertiesSet() throws Exception {
       initialize()
    }

    private void initialize() {
       //....
    }
}

After that small change everything worked.

Although there is one thing that might be worth mentioning. After I make it working I decided to make this field private and provide setter with straight argument type in the setter method. Unfortunately it wont work that. It causes org.springframework.beans.NotWritablePropertyException with message:

Invalid property 'providers[google]' of bean class [com.zinvoice.user.service.OAuth2ProvidersService]: Cannot access indexed value in property referenced in indexed property path 'providers[google]'; nested exception is org.springframework.beans.NotReadablePropertyException: Invalid property 'providers[google]' of bean class [com.zinvoice.user.service.OAuth2ProvidersService]: Bean property 'providers[google]' is not readable or has an invalid getter method: Does the return type of the getter match the parameter type of the setter?

Keep it in mind if you're using Groovy in your Spring Boot application.

Does a TCP socket connection have a "keep alive"?

TCP keepalive and HTTP keepalive are very different concepts. In TCP, the keepalive is the administrative packet sent to detect stale connection. In HTTP, keepalive means the persistent connection state.

This is from TCP specification,

Keep-alive packets MUST only be sent when no data or acknowledgement packets have been received for the connection within an interval. This interval MUST be configurable and MUST default to no less than two hours.

As you can see, the default TCP keepalive interval is too long for most applications. You might have to add keepalive in your application protocol.

Error: [$resource:badcfg] Error in resource configuration. Expected response to contain an array but got an object?

Also, if your service is sending an object instead of an array add isArray:false to its declaration.

'query': {method: 'GET', isArray: false }

Error inflating class android.support.v7.widget.Toolbar?

In the case of Xamarin in VS, you must add

Theme = "@style/MyThemesss"

to youractivity.cs.

I add this and go on.

How to configure heroku application DNS to Godaddy Domain?

You can't use the naked domain of your-domain.com if it is not redirected to the www.your-domain.com. Heroku use the www.yourdomain.com which act here as a subdomain. So when you follow the default instruction to use your-domain.com then you will need to assign both of them.

We can actually assign only the naked domain without the www.your-domain.com. Use only your-domain.com when the domain's dns provider (NameServers) support ALIAS or ANAME for the @ Record to example.herokuapp.com without CNAME www.your-domain.com to it.

It will let you to point www.your-domain.com to other hosting separately (independent).

How to change the pop-up position of the jQuery DatePicker control

fix show position problem daterangepicker.jQuery.js

//Original Code
//show, hide, or toggle rangepicker
    function showRP() {
        if (rp.data('state') == 'closed') {
            rp.data('state', 'open');
            rp.fadeIn(300);
            options.onOpen();
        }
    }


//Fixed
//show, hide, or toggle rangepicker
    function showRP() {
        rp.parent().css('left', rangeInput.offset().left);
        rp.parent().css('top', rangeInput.offset().top + rangeInput.outerHeight());
        if (rp.data('state') == 'closed') {
            rp.data('state', 'open');
            rp.fadeIn(300);
            options.onOpen();
        }
    }

java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication Maven

I had the same problem and tried most of the solutions suggested above, but none worked for me. Eventually, I rebuild my entire com.springframework (maven) repository (by simply deleting .m2/org/springworkframework directory).

It worked for me.

How to access the contents of a vector from a pointer to the vector in C++?

vector <int> numbers {10,20,30,40};
vector <int> *ptr {nullptr};

ptr = &numbers;

for(auto num: *ptr){
 cout << num << endl;
}


cout << (*ptr).at(2) << endl; // 20

cout << "-------" << endl;

cout << ptr -> at(2) << endl; // 20

Getting the PublicKeyToken of .Net assemblies

Open a command prompt and type one of the following lines according to your Visual Studio version and Operating System Architecture :

VS 2008 on 32bit Windows :

"%ProgramFiles%\Microsoft SDKs\Windows\v6.0A\bin\sn.exe" -T <assemblyname>

VS 2008 on 64bit Windows :

"%ProgramFiles(x86)%\Microsoft SDKs\Windows\v6.0A\bin\sn.exe" -T <assemblyname>

VS 2010 on 32bit Windows :

"%ProgramFiles%\Microsoft SDKs\Windows\v7.0A\bin\sn.exe" -T <assemblyname>

VS 2010 on 64bit Windows :

"%ProgramFiles(x86)%\Microsoft SDKs\Windows\v7.0A\bin\sn.exe" -T <assemblyname>

VS 2012 on 32bit Windows :

"%ProgramFiles%\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools\sn.exe" -T <assemblyname>

VS 2012 on 64bit Windows :

"%ProgramFiles(x86)%\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools\sn.exe" -T <assemblyname>

VS 2015 on 64bit Windows :

"%ProgramFiles(x86)%\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6.1 Tools\sn.exe" -T <assemblyname>

Note that for the versions VS2012+, sn.exe application isn't anymore in bin but in a sub-folder. Also, note that for 64bit you need to specify (x86) folder.

If you prefer to use Visual Studio command prompt, just type :

sn -T <assembly> 

where <assemblyname> is a full file path to the assembly you're interested in, surrounded by quotes if it has spaces.

You can add this as an external tool in VS, as shown here:
http://blogs.msdn.com/b/miah/archive/2008/02/19/visual-studio-tip-get-public-key-token-for-a-stong-named-assembly.aspx

Can't check signature: public key not found

You need the public key in your gpg key ring. To import the public key into your public keyring, place the public key block in a text file with a .gpg extension, and then issue the following command:

gpg --import <your-file>.gpg

The entity that encrypted the file should provide you with such a block. For example, ftp://ftp.gnu.org/gnu/gnu-keyring.gpg has the block for gnu.org.

For an even more in-depth explanation see Verifying files with GPG, without a .sig or .asc file?

pip not working in Python Installation in Windows 10

instead of typing in "python". try using "py". for ex:

py -m pip install    packagename
py -m pip --install  packagename
py -m pip --upgrade  packagename
py -m pip upgrade    packagename

note: this should be done in the command prompt "cmd" and not in python idle. also FYI pip is installed with python 3.6 automatically.

Complex numbers usage in python

In python, you can put ‘j’ or ‘J’ after a number to make it imaginary, so you can write complex literals easily:

>>> 1j
1j
>>> 1J
1j
>>> 1j * 1j
(-1+0j)

The ‘j’ suffix comes from electrical engineering, where the variable ‘i’ is usually used for current. (Reasoning found here.)

The type of a complex number is complex, and you can use the type as a constructor if you prefer:

>>> complex(2,3)
(2+3j)

A complex number has some built-in accessors:

>>> z = 2+3j
>>> z.real
2.0
>>> z.imag
3.0
>>> z.conjugate()
(2-3j)

Several built-in functions support complex numbers:

>>> abs(3 + 4j)
5.0
>>> pow(3 + 4j, 2)
(-7+24j)

The standard module cmath has more functions that handle complex numbers:

>>> import cmath
>>> cmath.sin(2 + 3j)
(9.15449914691143-4.168906959966565j)

Failed to execute 'postMessage' on 'DOMWindow': The target origin provided does not match the recipient window's origin ('null')

In My Case, Im trying to pass messages from Salesforce Marketing Cloud Custom Activity(Domain 1) to Heroku(Domain 2) on load.

The Error Appeared in console, when I loaded my original html page from where message is being passed.

Issue I noticed after reading many blogs is that, the receiver page is not loaded yet. i.e

I need to debug from my receiver page not from sender page.

Simple but glad if it helps anyone.

Java String import

Everything in the java.lang package is implicitly imported (including String) and you do not need to do so yourself. This is simply a feature of the Java language. ArrayList and HashMap are however in the java.util package, which is not implicitly imported.

The package java.lang mostly includes essential features, such a class version of primitives, basic exceptions and the Object class. This being integral to most programs, forcing people to import them is redundant and thus the contents of this package are implicitly imported.

Restful API service

Also when I hit the post(Config.getURL("login"), values) the app seems to pause for a while (seems weird - thought the idea behind a service was that it runs on a different thread!)

In this case its better to use asynctask, which runs on a different thread and return result back to the ui thread on completion.

Better way to right align text in HTML Table

A number of years ago (in the IE only days) I was using the <col align="right"> tag, but I just tested it and and it seems to be an IE only feature:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>Test</title>
</head>
<body>
    <table width="100%" border="1">
        <col align="left" />
        <col align="left" />
        <col align="right" />
        <tr>
            <th>ISBN</th>
            <th>Title</th>
            <th>Price</th>
        </tr>
        <tr>
            <td>3476896</td>
            <td>My first HTML</td>
            <td>$53</td>
        </tr>
    </table>
</body>
</html>

The snippet is taken from www.w3schools.com. Of course, it should not be used (unless for some reason you really target the IE rendering engine only), but I thought it would be interesting to mention it.

Edit:

Overall, I don't understand the reasoning behing abandoning this tag. It would appear to be very useful (at least for manual HTML publishing).

Why don't self-closing script elements work?

In case anyone's curious, the ultimate reason is that HTML was originally a dialect of SGML, which is XML's weird older brother. In SGML-land, elements can be specified in the DTD as either self-closing (e.g. BR, HR, INPUT), implicitly closeable (e.g. P, LI, TD), or explicitly closeable (e.g. TABLE, DIV, SCRIPT). XML, of course, has no concept of this.

The tag-soup parsers used by modern browsers evolved out of this legacy, although their parsing model isn't pure SGML anymore. And of course, your carefully-crafted XHTML is being treated as badly-written SGML-inspired tag-soup unless you send it with an XML mime type. This is also why...

<p><div>hello</div></p>

...gets interpreted by the browser as:

<p></p><div>hello</div><p></p>

...which is the recipe for a lovely obscure bug that can throw you into fits as you try to code against the DOM.

Stretch background image css?

This works flawlessly @ 2019

.marketing-panel  {
    background-image: url("../images/background.jpg");
    background-repeat: no-repeat;
    background-size: auto;
    background-position: center;
}

Appending a line to a file only if it does not already exist

This would be a clean, readable and reusable solution using grep and echo to add a line to a file only if it doesn't already exist:

LINE='include "/configs/projectname.conf"'
FILE='lighttpd.conf'
grep -qF -- "$LINE" "$FILE" || echo "$LINE" >> "$FILE"

If you need to match the whole line use grep -xqF

Add -s to ignore errors when the file does not exist, creating a new file with just that line.

Getting return value from stored procedure in C#

retval.Direction = ParameterDirection.Output;

ParameterDirection.ReturnValue should be used for the "return value" of the procedure, not output parameters. It gets the value returned by the SQL RETURN statement (with the parameter named @RETURN_VALUE).

Instead of RETURN @b you should SET @b = something

By the way, return value parameter is always int, not string.

UIView touch event in controller

Updating @Crashalot's answer for Swift 3.x:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let currentPoint = touch.location(in: self)
        // do something with your currentPoint
    }
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let currentPoint = touch.location(in: self)
        // do something with your currentPoint
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let currentPoint = touch.location(in: self)
        // do something with your currentPoint
    }
}

Copying the cell value preserving the formatting from one cell to another in excel using VBA

Copying the Bold Text From one sheet to another sheet in excel By using VBScript 'Create instance Object

Set oXL = CreateObject("Excel.application")
oXL.Visible = True

Set oWB = oXL.Workbooks.Open("FilePath.xlsx")
Set oSheet = oWB.Worksheets("Sheet1")         'Source Sheet in workbook
Set oDestSheet = oWB.Worksheets("Sheet2")       'Destination sheet in workbook

r = oSheet.usedrange.rows.Count
c = oSheet.usedrange.columns.Count

For i = 1 To r
    For j = 1 To c
        If oSheet.Cells(i,j).font.Bold = True Then

            oSheet.cells(i,j).copy
            oDestSheet.Cells(i,j).pastespecial
        End If
    Next
Next

oWB.Close
oXL.Quit

Linq to Entities - SQL "IN" clause

Seriously? You folks have never used

where (t.MyTableId == 1 || t.MyTableId == 2 || t.MyTableId == 3)

How to get single value of List<object>

You can access the fields by indexing the object array:

foreach (object[] item in selectedValues)
{
  idTextBox.Text = item[0];
  titleTextBox.Text = item[1];
  contentTextBox.Text = item[2];
}

That said, you'd be better off storing the fields in a small class of your own if the number of items is not dynamic:

public class MyObject
{
    public int Id { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
}

Then you can do:

foreach (MyObject item in selectedValues)
{
  idTextBox.Text = item.Id;
  titleTextBox.Text = item.Title;
  contentTextBox.Text = item.Content;
}

How do I access the $scope variable in browser's console using AngularJS?

Somewhere in your controller (often the last line is a good place), put

console.log($scope);

If you want to see an inner/implicit scope, say inside an ng-repeat, something like this will work.

<li ng-repeat="item in items">
   ...
   <a ng-click="showScope($event)">show scope</a>
</li>

Then in your controller

function MyCtrl($scope) {
    ...
    $scope.showScope = function(e) {
        console.log(angular.element(e.srcElement).scope());
    }
}

Note that above we define the showScope() function in the parent scope, but that's okay... the child/inner/implicit scope can access that function, which then prints out the scope based on the event, and hence the scope associated with the element that fired the event.

@jm-'s suggestion also works, but I don't think it works inside a jsFiddle. I get this error on jsFiddle inside Chrome:

> angular.element($0).scope()
ReferenceError: angular is not defined

How to convert UTF-8 byte[] to string?

Try this console app:

static void Main(string[] args)
{
    //Encoding _UTF8 = Encoding.UTF8;
    string[] _mainString = { "Héllo World" };
    Console.WriteLine("Main String: " + _mainString);

    //Convert a string to utf-8 bytes.
    byte[] _utf8Bytes = Encoding.UTF8.GetBytes(_mainString[0]);

    //Convert utf-8 bytes to a string.
    string _stringuUnicode = Encoding.UTF8.GetString(_utf8Bytes);
    Console.WriteLine("String Unicode: " + _stringuUnicode);
}

How can I pass selected row to commandLink inside dataTable or ui:repeat?

In JSF 1.2 this was done by <f:setPropertyActionListener> (within the command component). In JSF 2.0 (EL 2.2 to be precise, thanks to BalusC) it's possible to do it like this: action="${filterList.insert(f.id)}

How to approach a "Got minus one from a read call" error when connecting to an Amazon RDS Oracle instance

I got this error message from using an oracle database in a docker despite the fact i had publish port to host option "-p 1521:1521". I was using jdbc url that was using ip address 127.0.0.1, i changed it to the host machine real ip address and everything worked then.

How to pass arguments to Shell Script through docker run

With Docker, the proper way to pass this sort of information is through environment variables.

So with the same Dockerfile, change the script to

#!/bin/bash
echo $FOO

After building, use the following docker command:

docker run -e FOO="hello world!" test

Change image onmouseover

<a href="" onMouseOver="document.MyImage.src='http://icons.iconarchive.com/icons/uiconstock/round-edge-social/72/ask-icon.png';" onMouseOut="document.MyImage.src='http://icons.iconarchive.com/icons/uiconstock/round-edge-social/72/arto-icon.png';">
<img src="http://icons.iconarchive.com/icons/uiconstock/round-edge-social/72/arto-icon.png" name="MyImage">

Demo http://jsfiddle.net/W6zs5/

req.body empty on posts

I discovered, that it works when sending with content type

"application/json"

in combination with server-side

app.use(bodyParser.json());

Now I can send via

var data = {name:"John"}
var xmlHttp = new XMLHttpRequest();
xmlHttp.open("POST", theUrl, false); // false for synchronous request
xmlHttp.setRequestHeader("Content-type", "application/json");
xmlHttp.send(data);

and the result is available in request.body.name on the server.

HTML text input field with currency symbol

Put the '$' in front of the text input field, instead of inside it. It makes validation for numeric data a lot easier because you don't have to parse out the '$' after submit.

You can, with JQuery.validate() (or other), add some client-side validation rules that handle currency. That would allow you to have the '$' inside the input field. But you still have to do server-side validation for security and that puts you back in the position of having to remove the '$'.

How Can I Truncate A String In jQuery?

  function truncateString(str, length) {
     return str.length > length ? str.substring(0, length - 3) + '...' : str
  }

Android M Permissions: onRequestPermissionsResult() not being called

private void showContacts() {
    if (getActivity().checkSelfPermission(Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {
        requestPermissions(new String[]{Manifest.permission.READ_CONTACTS}, PERMISSIONS_REQUEST_READ_CONTACTS);
    } else {
        doShowContacts();
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    if (requestCode == PERMISSIONS_REQUEST_READ_CONTACTS && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        doShowContacts();
    }
}