Programs & Examples On #Deepzoom

Deep Zoom provides the ability to interactively view high-resolution images

How to get an HTML element's style values in javascript?

You can make function getStyles that'll take an element and other arguments are properties that's values you want.

const convertRestArgsIntoStylesArr = ([...args]) => {
    return args.slice(1);
}

const getStyles = function () {
    const args = [...arguments];
    const [element] = args;

    let stylesProps = [...args][1] instanceof Array ? args[1] : convertRestArgsIntoStylesArr(args);

    const styles = window.getComputedStyle(element);
    const stylesObj = stylesProps.reduce((acc, v) => {
        acc[v] = styles.getPropertyValue(v);
        return acc;
    }, {});

    return stylesObj;
};

Now, you can use this function like this:

const styles = getStyles(document.body, "height", "width");

OR

const styles = getStyles(document.body, ["height", "width"]);

How do I calculate tables size in Oracle

First, gather optimiser stats on the table (if you haven't already):

begin
   dbms_stats.gather_table_stats('MYSCHEMA','MYTABLE');
end;
/

WARNING: As Justin says in his answer, gathering optimiser stats affects query optimisation and should not be done without due care and consideration!

Then find the number of blocks occupied by the table from the generated stats:

select blocks, empty_blocks, num_freelist_blocks
from   all_tables
where  owner = 'MYSCHEMA'
and    table_name = 'MYTABLE';
  • The total number of blocks allocated to the table is blocks + empty_blocks + num_freelist_blocks.

  • blocks is the number of blocks that actually contain data.

Multiply the number of blocks by the block size in use (usually 8KB) to get the space consumed - e.g. 17 blocks x 8KB = 136KB.

To do this for all tables in a schema at once:

begin
    dbms_stats.gather_schema_stats ('MYSCHEMA');
end;
/

select table_name, blocks, empty_blocks, num_freelist_blocks
from   user_tables;

Note: Changes made to the above after reading this AskTom thread

How to resolve the C:\fakepath?

Use

document.getElementById("file-id").files[0].name; 

instead of

document.getElementById('file-id').value

REST API Best practice: How to accept list of parameter values as input

A Step Back

First and foremost, REST describes a URI as a universally unique ID. Far too many people get caught up on the structure of URIs and which URIs are more "restful" than others. This argument is as ludicrous as saying naming someone "Bob" is better than naming him "Joe" – both names get the job of "identifying a person" done. A URI is nothing more than a universally unique name.

So in REST's eyes arguing about whether ?id=["101404","7267261"] is more restful than ?id=101404,7267261 or \Product\101404,7267261 is somewhat futile.

Now, having said that, many times how URIs are constructed can usually serve as a good indicator for other issues in a RESTful service. There are a couple of red flags in your URIs and question in general.

Suggestions

  1. Multiple URIs for the same resource and Content-Location

    We may want to accept both styles but does that flexibility actually cause more confusion and head aches (maintainability, documentation, etc.)?

    URIs identify resources. Each resource should have one canonical URI. This does not mean that you can't have two URIs point to the same resource but there are well defined ways to go about doing it. If you do decide to use both the JSON and list based formats (or any other format) you need to decide which of these formats is the main canonical URI. All responses to other URIs that point to the same "resource" should include the Content-Location header.

    Sticking with the name analogy, having multiple URIs is like having nicknames for people. It is perfectly acceptable and often times quite handy, however if I'm using a nickname I still probably want to know their full name – the "official" way to refer to that person. This way when someone mentions someone by their full name, "Nichloas Telsa", I know they are talking about the same person I refer to as "Nick".

  2. "Search" in your URI

    A more complex case is when we want to offer more complex inputs. For example, if we want to allow multiple filters on search...

    A general rule of thumb of mine is, if your URI contains a verb, it may be an indication that something is off. URI's identify a resource, however they should not indicate what we're doing to that resource. That's the job of HTTP or in restful terms, our "uniform interface".

    To beat the name analogy dead, using a verb in a URI is like changing someone's name when you want to interact with them. If I'm interacting with Bob, Bob's name doesn't become "BobHi" when I want to say Hi to him. Similarly, when we want to "search" Products, our URI structure shouldn't change from "/Product/..." to "/Search/...".

Answering Your Initial Question

  1. Regarding ["101404","7267261"] vs 101404,7267261: My suggestion here is to avoid the JSON syntax for simplicity's sake (i.e. don't require your users do URL encoding when you don't really have to). It will make your API a tad more usable. Better yet, as others have recommended, go with the standard application/x-www-form-urlencoded format as it will probably be most familiar to your end users (e.g. ?id[]=101404&id[]=7267261). It may not be "pretty", but Pretty URIs does not necessary mean Usable URIs. However, to reiterate my initial point though, ultimately when speaking about REST, it doesn't matter. Don't dwell too heavily on it.

  2. Your complex search URI example can be solved in very much the same way as your product example. I would recommend going the application/x-www-form-urlencoded format again as it is already a standard that many are familiar with. Also, I would recommend merging the two.

Your URI...

/Search?term=pumas&filters={"productType":["Clothing","Bags"],"color":["Black","Red"]}    

Your URI after being URI encoded...

/Search?term=pumas&filters=%7B%22productType%22%3A%5B%22Clothing%22%2C%22Bags%22%5D%2C%22color%22%3A%5B%22Black%22%2C%22Red%22%5D%7D

Can be transformed to...

/Product?term=pumas&productType[]=Clothing&productType[]=Bags&color[]=Black&color[]=Red

Aside from avoiding the requirement of URL encoding and making things look a bit more standard, it now homogenizes the API a bit. The user knows that if they want to retrieve a Product or List of Products (both are considered a single "resource" in RESTful terms), they are interested in /Product/... URIs.

How to prevent colliders from passing through each other?

I have a pinball prototype that also gave me much trouble in the same areas. These are all the steps I've taken to almost (but not yet entirely) solve these problems:

For fast moving objects:

  • Set the rigidbody's Interpolate to 'Interpolate' (this does not affect the actual physics simulation, but updates the rendering of the object properly - use this only on important objects from a rendering point of view, like the player, or a pinball, but not for projectiles)

  • Set Collision Detection to Continuous Dynamic

  • Attach the script DontGoThroughThings (https://www.auto.tuwien.ac.at/wordpress/?p=260) to your object. This script cleverly uses the Raycasting solution I posted in my other answer to pull back offending objects to before the collision points.

In Edit -> Project Settings -> Physics:

  • Set Min Penetration for Penalty to a very low value. I've set mine to 0.001

  • Set Solver Iteration Count to a higher value. I've set mine to 50, but you can probably do ok with much less.

All that is going to have a penalty in performace, but that's unavoidable. The defaults values are soft on performance but are not really intented for proper simulation of small and fast-moving objects.

How to remove the last character from a bash grep output

Using sed, if you don't know what the last character actually is:

$ grep company_name file.txt | cut -d '=' -f2 | sed 's/.$//'
"Abc Inc"

How do I change the text of a span element using JavaScript?

For this span

<span id="name">sdfsdf</span>

You can go like this :-

$("name").firstChild.nodeValue = "Hello" + "World";

Assign null to a SqlParameter

If you use the conditional(ternary) operator the compiler needs an implicit conversion between both types, otherwise you get an exception.

So you could fix it by casting one of both to System.Object:

planIndexParameter.Value = (AgeItem.AgeIndex== null) ? DBNull.Value : (object) AgeItem.AgeIndex;

But since the result is not really pretty and you always have to remember this casting, you could use such an extension method instead:

public static object GetDBNullOrValue<T>(this T val)
{
    bool isDbNull = true;
    Type t = typeof(T);

    if (Nullable.GetUnderlyingType(t) != null)
        isDbNull = EqualityComparer<T>.Default.Equals(default(T), val);
    else if (t.IsValueType)
        isDbNull = false;
    else
        isDbNull = val == null;

    return isDbNull ? DBNull.Value : (object) val;
}

Then you can use this concise code:

planIndexParameter.Value = AgeItem.AgeIndex.GetDBNullOrValue();

Could not read JSON: Can not deserialize instance of hello.Country[] out of START_OBJECT token

If you want to avoid using an extra Class and List<Object> genomes you could simply use a Map.

The data structure translates into Map<String, List<Country>>

String resourceEndpoint = "http://api.geonames.org/countryInfoJSON?username=volodiaL";

Map<String, List<Country>> geonames = restTemplate.getForObject(resourceEndpoint, Map.class);

List<Country> countries = geonames.get("geonames");

Build project into a JAR automatically in Eclipse

Using Thomas Bratt's answer above, just make sure your build.xml is configured properly :

<?xml version="1.0" ?>
<!-- Configuration of the Ant build system to generate a Jar file --> 
<project name="TestMain" default="CreateJar">
  <target name="CreateJar" description="Create Jar file">
        <jar jarfile="Test.jar" basedir="bin/" includes="**/*.class" />
  </target>
</project>

(Notice the double asterisk - it will tell build to look for .class files in all sub-directories.)

Where/How to getIntent().getExtras() in an Android Fragment?

What I tend to do, and I believe this is what Google intended for developers to do too, is to still get the extras from an Intent in an Activity and then pass any extra data to fragments by instantiating them with arguments.

There's actually an example on the Android dev blog that illustrates this concept, and you'll see this in several of the API demos too. Although this specific example is given for API 3.0+ fragments, the same flow applies when using FragmentActivity and Fragment from the support library.

You first retrieve the intent extras as usual in your activity and pass them on as arguments to the fragment:

public static class DetailsActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // (omitted some other stuff)

        if (savedInstanceState == null) {
            // During initial setup, plug in the details fragment.
            DetailsFragment details = new DetailsFragment();
            details.setArguments(getIntent().getExtras());
            getSupportFragmentManager().beginTransaction().add(
                    android.R.id.content, details).commit();
        }
    }
}

In stead of directly invoking the constructor, it's probably easier to use a static method that plugs the arguments into the fragment for you. Such a method is often called newInstance in the examples given by Google. There actually is a newInstance method in DetailsFragment, so I'm unsure why it isn't used in the snippet above...

Anyways, all extras provided as argument upon creating the fragment, will be available by calling getArguments(). Since this returns a Bundle, its usage is similar to that of the extras in an Activity.

public static class DetailsFragment extends Fragment {
    /**
     * Create a new instance of DetailsFragment, initialized to
     * show the text at 'index'.
     */
    public static DetailsFragment newInstance(int index) {
        DetailsFragment f = new DetailsFragment();

        // Supply index input as an argument.
        Bundle args = new Bundle();
        args.putInt("index", index);
        f.setArguments(args);

        return f;
    }

    public int getShownIndex() {
        return getArguments().getInt("index", 0);
    }

    // (other stuff omitted)

}

jQuery & CSS - Remove/Add display:none

jQuery provides you with:

$(".news").hide();
$(".news").show();

You can then easily show and hide the element(s).

How to restart VScode after editing extension's config?

You can do the following

  1. Click on extensions
  2. Type Reload
  3. Then install

It will add a reload button on your right hand at the bottom of the vs code.

How to set a value for a span using jQuery

You can do:

$("#submittername").text("testing");

or

$("#submittername").html("testing <b>1 2 3</b>");

How to override a JavaScript function

You can override any built-in function by just re-declaring it.

parseFloat = function(a){
  alert(a)
};

Now parseFloat(3) will alert 3.

How do I fix this "TypeError: 'str' object is not callable" error?

You are trying to use the string as a function:

"Your new price is: $"(float(price) * 0.1)

Because there is nothing between the string literal and the (..) parenthesis, Python interprets that as an instruction to treat the string as a callable and invoke it with one argument:

>>> "Hello World!"(42)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable

Seems you forgot to concatenate (and call str()):

easygui.msgbox("Your new price is: $" + str(float(price) * 0.1))

The next line needs fixing as well:

easygui.msgbox("Your new price is: $" + str(float(price) * 0.2))

Alternatively, use string formatting with str.format():

easygui.msgbox("Your new price is: ${:.2f}".format(float(price) * 0.1))
easygui.msgbox("Your new price is: ${:.2f}".format(float(price) * 0.2))

where {:02.2f} will be replaced by your price calculation, formatting the floating point value as a value with 2 decimals.

Get class name using jQuery

If we have a code:

<div id="myDiv" class="myClass myClass2"></div> 

to take class name by using jQuery we could define and use a simple plugin method:

$.fn.class = function(){
  return Array.prototype.slice.call( $(this)[0].classList );
}

or

 $.fn.class = function(){
   return $(this).prop('class');
 } 

The use of the method will be:

$('#myDiv').class();

We have to notice that it will return a list of classes unlike of native method element.className which returns only first class of the attached classes. Because often the element has more than one class attached to it, I recommend you not to use this native method but element.classlist or the method described above.

The first variant of it will return a list of classes as an array, the second as a string - class names separated by spaces:

// [myClass, myClass2]
// "myClass myClass2"

Another important notice is that both methods as well as jQuery method

$('div').prop('class');

return only class list of the first element caught by the jQuery object if we use a more common selector which points many other elements. In such a case we have to mark the element, we want to get his classes, by using some index, e.g.

$('div:eq(2)').prop('class');

It depends also what you need to do with these classes. If you want just to check for a class into the class list of the element with this id you should just use method "hasClass":

if($('#myDiv').hasClass('myClass')){
   // do something
}

as mentioned in the comments above. But if you could need to take all classes as a selector, then use this code:

$.fn.classes = function(){
   var o = $(this);
   return o.prop('class')? [''].concat( o.prop('class').split(' ') ).join('.') : '';
 } 

 var mySelector = $('#myDiv').classes();

The result will be:

// .myClass.myClass2

and you could get it to create dynamically a specific rewriting css rule for example.

Regards

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2

I was running into a similar error in pywikipediabot. The .decode method is a step in the right direction but for me it didn't work without adding 'ignore':

ignore_encoding = lambda s: s.decode('utf8', 'ignore')

Ignoring encoding errors can lead to data loss or produce incorrect output. But if you just want to get it done and the details aren't very important this can be a good way to move faster.

How to debug JavaScript / jQuery event bindings with Firebug or similar tools?

Here's a plugin which can list all event handlers for any given element/event:

$.fn.listHandlers = function(events, outputFunction) {
    return this.each(function(i){
        var elem = this,
            dEvents = $(this).data('events');
        if (!dEvents) {return;}
        $.each(dEvents, function(name, handler){
            if((new RegExp('^(' + (events === '*' ? '.+' : events.replace(',','|').replace(/^on/i,'')) + ')$' ,'i')).test(name)) {
               $.each(handler, function(i,handler){
                   outputFunction(elem, '\n' + i + ': [' + name + '] : ' + handler );
               });
           }
        });
    });
};

Use it like this:

// List all onclick handlers of all anchor elements:
$('a').listHandlers('onclick', console.info);

// List all handlers for all events of all elements:
$('*').listHandlers('*', console.info);

// Write a custom output function:
$('#whatever').listHandlers('click',function(element,data){
    $('body').prepend('<br />' + element.nodeName + ': <br /><pre>' + data + '<\/pre>');
});

Src: (my blog) -> http://james.padolsey.com/javascript/debug-jquery-events-with-listhandlers/

How to cut first n and last n columns?

The first part of your question is easy. As already pointed out, cut accepts omission of either the starting or the ending index of a column range, interpreting this as meaning either “from the start to column n (inclusive)” or “from column n (inclusive) to the end,” respectively:

$ printf 'this:is:a:test' | cut -d: -f-2
this:is
$ printf 'this:is:a:test' | cut -d: -f3-
a:test

It also supports combining ranges. If you want, e.g., the first 3 and the last 2 columns in a row of 7 columns:

$ printf 'foo:bar:baz:qux:quz:quux:quuz' | cut -d: -f-3,6-
foo:bar:baz:quux:quuz

However, the second part of your question can be a bit trickier depending on what kind of input you’re expecting. If by “last n columns” you mean “last n columns (regardless of their indices in the overall row)” (i.e. because you don’t necessarily know how many columns you’re going to find in advance) then sadly this is not possible to accomplish using cut alone. In order to effectively use cut to pull out “the last n columns” in each line, the total number of columns present in each line must be known beforehand, and each line must be consistent in the number of columns it contains.

If you do not know how many “columns” may be present in each line (e.g. because you’re working with input that is not strictly tabular), then you’ll have to use something like awk instead. E.g., to use awk to pull out the last 2 “columns” (awk calls them fields, the number of which can vary per line) from each line of input:

$ printf '/a\n/a/b\n/a/b/c\n/a/b/c/d\n' | awk -F/ '{print $(NF-1) FS $(NF)}'
/a
a/b
b/c
c/d

Download a working local copy of a webpage

wget is capable of doing what you are asking. Just try the following:

wget -p -k http://www.example.com/

The -p will get you all the required elements to view the site correctly (css, images, etc). The -k will change all links (to include those for CSS & images) to allow you to view the page offline as it appeared online.

From the Wget docs:

‘-k’
‘--convert-links’
After the download is complete, convert the links in the document to make them
suitable for local viewing. This affects not only the visible hyperlinks, but
any part of the document that links to external content, such as embedded images,
links to style sheets, hyperlinks to non-html content, etc.

Each link will be changed in one of the two ways:

    The links to files that have been downloaded by Wget will be changed to refer
    to the file they point to as a relative link.

    Example: if the downloaded file /foo/doc.html links to /bar/img.gif, also
    downloaded, then the link in doc.html will be modified to point to
    ‘../bar/img.gif’. This kind of transformation works reliably for arbitrary
    combinations of directories.

    The links to files that have not been downloaded by Wget will be changed to
    include host name and absolute path of the location they point to.

    Example: if the downloaded file /foo/doc.html links to /bar/img.gif (or to
    ../bar/img.gif), then the link in doc.html will be modified to point to
    http://hostname/bar/img.gif. 

Because of this, local browsing works reliably: if a linked file was downloaded,
the link will refer to its local name; if it was not downloaded, the link will
refer to its full Internet address rather than presenting a broken link. The fact
that the former links are converted to relative links ensures that you can move
the downloaded hierarchy to another directory.

Note that only at the end of the download can Wget know which links have been
downloaded. Because of that, the work done by ‘-k’ will be performed at the end
of all the downloads. 

How to get rid of the "No bootable medium found!" error in Virtual Box?

Try this:

Go to virtual box > right click the OS > settings > under one of the many tab that I don't remember(sorry for this, i dont have vbox installed)> locate the VDI (virtual box disk image) file..

and save the settings.. then try to start the OS..

JavaScript - Getting HTML form values

Please try to change the code as below:

<form
   onSubmit={e => {
     e.preventDefault();
     e.stopPropagation();

     const elements = Array.from(e.currentTarget) as HTMLInputElement[];

     const state = elements.reduce((acc, el) => {
       if (el.name) {
         acc[el.name] = el.value;
       }

       return acc;
     }, {});

     console.log(state); // {test: '123'}
   }}
>
   <input name='test' value='123' />
</form>

ansible: lineinfile for several lines?

To add multiple lines you can use blockfile:

- name: Add mappings to /etc/hosts
  blockinfile:
    path: /etc/hosts
    block: |
      '10.10.10.10  server.example.com'
      '10.10.10.11  server1.example.com'

to Add one line you can use lininfile:

- name: server.example.com in /etc/hosts
  lineinfile:
    path: /etc/hosts
    line: '192.0.2.42 server.example.com server'
    state: present

Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?

Because a 32-bit floating-point number - such as 1.024 - is not 1.024. In a computer, 1.024 is an interval: from (1.024-e) to (1.024+e), where "e" represents an error. Some people fail to realize this and also believe that * in a*a stands for multiplication of arbitrary-precision numbers without there being any errors attached to those numbers. The reason why some people fail to realize this is perhaps the math computations they exercised in elementary schools: working only with ideal numbers without errors attached, and believing that it is OK to simply ignore "e" while performing multiplication. They do not see the "e" implicit in "float a=1.2", "a*a*a" and similar C codes.

Should majority of programmers recognize (and be able to execute on) the idea that C expression a*a*a*a*a*a is not actually working with ideal numbers, the GCC compiler would then be FREE to optimize "a*a*a*a*a*a" into say "t=(a*a); t*t*t" which requires a smaller number of multiplications. But unfortunately, the GCC compiler does not know whether the programmer writing the code thinks that "a" is a number with or without an error. And so GCC will only do what the source code looks like - because that is what GCC sees with its "naked eye".

... once you know what kind of programmer you are, you can use the "-ffast-math" switch to tell GCC that "Hey, GCC, I know what I am doing!". This will allow GCC to convert a*a*a*a*a*a into a different piece of text - it looks different from a*a*a*a*a*a - but still computes a number within the error interval of a*a*a*a*a*a. This is OK, since you already know you are working with intervals, not ideal numbers.

Get POST data in C#/ASP.NET

Try using:

string ap = c.Request["AP"];

That reads from the cookies, form, query string or server variables.

Alternatively:

string ap = c.Request.Form["AP"];

to just read from the form's data.

What rules does software version numbering follow?

The usual method I have seen is X.Y.Z, which generally corresponds to major.minor.patch:

  • Major version numbers change whenever there is some significant change being introduced. For example, a large or potentially backward-incompatible change to a software package.
  • Minor version numbers change when a new, minor feature is introduced or when a set of smaller features is rolled out.
  • Patch numbers change when a new build of the software is released to customers. This is normally for small bug-fixes or the like.

Other variations use build numbers as an additional identifier. So you may have a large number for X.Y.Z.build if you have many revisions that are tested between releases. I use a couple of packages that are identified by year/month or year/release. Thus, a release in the month of September of 2010 might be 2010.9 or 2010.3 for the 3rd release of this year.

There are many variants to versioning. It all boils down to personal preference.

For the "1.3v1.1", that may be two different internal products, something that would be a shared library / codebase that is rev'd differently from the main product; that may indicate version 1.3 for the main product, and version 1.1 of the internal library / package.

How to execute the start script with Nodemon

I have a TypeScript file called "server.ts", The following npm scripts configures Nodemon and npm to start my app and monitor for any changes on TypeScript files:

"start": "nodemon -e ts  --exec \"npm run myapp\"",
"myapp": "tsc -p . && node server.js",

I already have Nodemon on dependencies. When I run npm start, it will ask Nodemon to monitor its files using the -e switch and then it calls the myapp npm script which is a simple combination of transpiling the typescript files and then starting the resulting server.js. When I change the TypeScript file, because of -e switch the same cycle happens and new .js files will be generated and executed.

conflicting types for 'outchar'

In C, the order that you define things often matters. Either move the definition of outchar to the top, or provide a prototype at the top, like this:

#include <stdio.h> #include <stdlib.h>  void outchar(char ch);  int main() {     outchar('A');     outchar('B');     outchar('C');     return 0; }  void outchar(char ch) {     printf("%c", ch); } 

Also, you should be specifying the return type of every function. I added that for you.

How can I change the font-size of a select option?

We need a trick here...

Normal select-dropdown things won't accept styles. BUT. If there's a "size" parameter in the tag, almost any CSS will apply. With this in mind, I've created a fiddle that's practically equivalent to a normal select tag, plus the value can be edited manually like a ComboBox in visual languages (unless you put readonly in the input tag).

A simplified example:

<style>

    /* only these 2 lines are truly required */
    .stylish span {position:relative;}
    .stylish select {position:absolute;left:0px;display:none}

    /* now you can style the hell out of them */
    .stylish input    { ... }
    .stylish select   { ... }
    .stylish option   { ... }
    .stylish optgroup { ... }

</style>
...
<div class="stylish">
    <label> Choose your superhero: </label>
    <span>
        <input onclick="$(this).closest('div').find('select').slideToggle(110)">
        <br>
        <select size=15 onclick="$(this).hide().closest('div').find('input').val($(this).find('option:selected').text());">

            <optgroup label="Fantasy"></optgroup>
            <option value="gandalf">Gandalf</option>
            <option value="harry">Harry Potter</option>
            <option value="jon">Jon Snow</option>

            <optgroup label="Comics"></optgroup>
            <option value="tony">Tony Stark</option>
            <option value="steve">Steven Rogers</option>
            <option value="natasha">Natasha Romanova</option>

        </select>
    </span>
    <!--

        For the sake of simplicity, I used jQuery here.
        Today it's easy to do the same without it, now
        that we have querySelector(), closest(), etc.

    -->
</div>

A live example:

https://jsfiddle.net/7ac9us70/1052/

Note 1: Sorry for the gradients & all fancy stuff, no they're not necessary, yes I'm showing off, I know, hashtag onlyhuman, hashtag notproud.

Note 2: Those <optgroup> tags don't encapsulate the options belonging under them as they normally should; this is intentional. It's better for the styling (the well-mannered way would be a lot less stylable), and yes this is painless and works in every browser.

Spring Data JPA map the native query result to Non-Entity POJO

In my computer, I get this code works.It's a little different from Daimon's answer.

_x000D_
_x000D_
@SqlResultSetMapping(_x000D_
    name="groupDetailsMapping",_x000D_
    classes={_x000D_
        @ConstructorResult(_x000D_
            targetClass=GroupDetails.class,_x000D_
            columns={_x000D_
                @ColumnResult(name="GROUP_ID",type=Integer.class),_x000D_
                @ColumnResult(name="USER_ID",type=Integer.class)_x000D_
            }_x000D_
        )_x000D_
    }_x000D_
)_x000D_
_x000D_
@NamedNativeQuery(name="User.getGroupDetails", query="SELECT g.*, gm.* FROM group g LEFT JOIN group_members gm ON g.group_id = gm.group_id and gm.user_id = :userId WHERE g.group_id = :groupId", resultSetMapping="groupDetailsMapping")
_x000D_
_x000D_
_x000D_

How do I import an SQL file using the command line in MySQL?

If you are importing to your local database server, you can do the following:

mysql -u database_user -p < database_file.sql

For a remote database server do the follwing:

mysql -u database_user -p -h remote_server_url < database_file.sql

Double quotes within php script echo

You need to escape ", so it won't be interpreted as end of string. Use \ to escape it:

echo "<script>$('#edit_errors').html('<h3><em><font color=\"red\">Please Correct Errors Before Proceeding</font></em></h3>')</script>";

Read more: strings and escape sequences

Why does CreateProcess give error 193 (%1 is not a valid Win32 app)

Let me add an example here:

I'm trying to build Alluxio on windows platform and got the same issue, it's because the pom.xml contains below step:

      <plugin>
        <artifactId>exec-maven-plugin</artifactId>
        <groupId>org.codehaus.mojo</groupId>
        <inherited>false</inherited>
        <executions>
          <execution>
            <id>Check that there are no Windows line endings</id>
            <phase>compile</phase>
            <goals>
              <goal>exec</goal>
            </goals>
            <configuration>
              <executable>${build.path}/style/check_no_windows_line_endings.sh</executable>
            </configuration>
          </execution>
        </executions>
      </plugin>

The .sh file is not executable on windows so the error throws.

Comment it out if you do want build Alluxio on windows.

How can I view the allocation unit size of a NTFS partition in Vista?

The simple GUI way, as provided by J Y in a previous answer:

  1. Create a small file (not empty)
  2. Right-click, choose Properties
  3. Check "Size on disk" (in tab General), double-check that your file size is less than half that so that it is certainly using a single allocation unit.

This works well and reminds you of the significance of allocation unit size. But it does have a caveat: as seen in comments to previous answer, Windows will sometimes show "Size on disk" as 0 for a very small file. In my testing, NTFS filesystems with allocation unit size 4096 bytes required the file to be 800 bytes to consistently avoid this issue. On FAT32 file systems this issue seems nonexistent, even a single byte file will work - just not empty.

Creating InetAddress object in Java

ip = InetAddress.getByAddress(new byte[] {
        (byte)192, (byte)168, (byte)0, (byte)102}
);

Can't access object property, even though it shows up in a console log

I was not getting the MongoDB error message in the thrown error in my NodeJS API response, so I did the following

// It was not working
console.log(error.message) // prints the error
let response = error;
// message property was not available in the response.
/* 
{
  "status": "error",
  "error": {
    "driver": true,
    "name": "MongoError",
    "index": 0,
    "code": 11000,
    "keyPattern": {
      "event_name": 1
    },
    "keyValue": {
      "event_name": "followup"
    }
  }
}
*/
// so I did this
let message = error.message;
let response = JSON.parse(JSON.stringify(error));
response.message = message;
// message property is now available in the response.
/* 
{
  "status": "error",
  "error": {
    "driver": true,
    "name": "MongoError",
    "index": 0,
    "code": 11000,
    "keyPattern": {
      "event_name": 1
    },
    "keyValue": {
      "event_name": "followup"
    },
    "message": "E11000 duplicate key error collection: mycollections.notificationevents index: event_name_1 dup key: { event_name: \"followup\" }"
  }
}
*/

Full width image with fixed height

#image {
  width: 100%;
  height: 100px; //static
  object-fit: cover;
}

Git/GitHub can't push to master

Mark Longair's solution using git remote set-url... is quite clear. You can also get the same behavior by directly editing this section of the .git/config file:

before:

[remote "origin"]
    fetch = +refs/heads/*:refs/remotes/origin/*
    url = git://github.com/my_user_name/my_repo.git

after:

[remote "origin"]
    fetch = +refs/heads/*:refs/remotes/origin/*
    url = [email protected]:my_user_name/my_repo.git

(And conversely, the git remote set-url... invocation produces the above change.)

What are static factory methods?

static

A member declared with the keyword 'static'.

factory methods

Methods that create and return new objects.

in Java

The programming language is relevant to the meaning of 'static' but not to the definition of 'factory'.

pip install returning invalid syntax

The problem is the OS can’t find Pip. Pip helps you install packages MODIFIED SOME GREAT ANSWERS TO BE BETTER

Method 1 Go to path of python, then search for pip

  1. open cmd.exe
  2. write the following command:

E.g

cd C:\Users\Username\AppData\Local\Programs\Python\Python37-32

In this directory, search pip with python -m pip then install package

E.g

python -m pip install ipywidgets

-m module-name Searches sys.path for the named module and runs the corresponding .py file as a script.

OR

GO TO scripts from CMD. This is where Pip stays :)

cd C:\Users\User name\AppData\Local\Programs\Python\Python37-32\Scripts>

Then

pip install anypackage

How do I build an import library (.lib) AND a DLL in Visual C++?

Does your DLL project have any actual exports? If there are no exports, the linker will not generate an import library .lib file.

In the non-Express version of VS, the import libray name is specfied in the project settings here:

Configuration Properties/Linker/Advanced/Import Library

I assume it's the same in Express (if it even provides the ability to configure the name).

What does "Error: object '<myvariable>' not found" mean?

I had a similar problem with R-studio. When I tried to do my plots, this message was showing up.

Eventually I realised that the reason behind this was that my "window" for the plots was too small, and I had to make it bigger to "fit" all the plots inside!

Hope to help

How to read and write excel file

There is a new easy and very cool tool (10x to Kfir): xcelite

Write:

public class User { 

  @Column (name="Firstname")
  private String firstName;

  @Column (name="Lastname")
  private String lastName;

  @Column
  private long id; 

  @Column
  private Date birthDate; 
}

Xcelite xcelite = new Xcelite();    
XceliteSheet sheet = xcelite.createSheet("users");
SheetWriter<User> writer = sheet.getBeanWriter(User.class);
List<User> users = new ArrayList<User>();
// ...fill up users
writer.write(users); 
xcelite.write(new File("users_doc.xlsx"));

Read:

Xcelite xcelite = new Xcelite(new File("users_doc.xlsx"));
XceliteSheet sheet = xcelite.getSheet("users");
SheetReader<User> reader = sheet.getBeanReader(User.class);
Collection<User> users = reader.read();

Display the current date and time using HTML and Javascript with scrollable effects in hta application

<div id="clockbox" style="font:14pt Arial; color:#FF0000;text-align: center; border:1px solid red;background:cyan; height:50px;padding-top:12px;"></div>

Compare cell contents against string in Excel

You can use the EXACT Function for exact string comparisons.

=IF(EXACT(A1, "ENG"), 1, 0)

Execute a large SQL script (with GO commands)

To avoid third parties, regexes, memory overheads and fast work with large scripts I created my own stream-based parser. It

  • checks syntax before
  • can recognize comments with -- or /**/

    -- some commented text
     /*
    drop table Users;
    GO
       */
    
  • can recognize string literals with ' or "

    set @s =
        'create table foo(...);
        GO
        create index ...';
    
  • preserves LF and CR formatting
  • preserves comments block in object bodies (stored procedures, views etc.)
  • and other constructions such as

          gO -- commented text
    

How to use

    try
    {
        using (SqlConnection connection = new SqlConnection("Integrated Security=SSPI;Persist Security Info=True;Initial Catalog=DATABASE-NAME;Data Source=SERVER-NAME"))
        {
            connection.Open();

            int rowsAffected = SqlStatementReader.ExecuteSqlFile(
                "C:\\target-sql-script.sql",
                connection,
                // Don't forget to use the correct file encoding!!!
                Encoding.Default,
                // Indefinitely (sec)
                0
            );
        }
    }
    // implement your handlers
    catch (SqlStatementReader.SqlBadSyntaxException) { }
    catch (SqlException) { }
    catch (Exception) { }

Stream-based SQL script reader

class SqlStatementReader
{
    public class SqlBadSyntaxException : Exception
    {
        public SqlBadSyntaxException(string description) : base(description) { }
        public SqlBadSyntaxException(string description, int line) : base(OnBase(description, line, null)) { }
        public SqlBadSyntaxException(string description, int line, string filePath) : base(OnBase(description, line, filePath)) { }
        private static string OnBase(string description, int line, string filePath)
        {
            if (filePath == null)
                return string.Format("Line: {0}. {1}", line, description);
            else
                return string.Format("File: {0}\r\nLine: {1}. {2}", filePath, line, description);
        }
    }

    enum SqlScriptChunkTypes
    {
        InstructionOrUnquotedIdentifier = 0,
        BracketIdentifier = 1,
        QuotIdentifierOrLiteral = 2,
        DblQuotIdentifierOrLiteral = 3,
        CommentLine = 4,
        CommentMultiline = 5,
    }

    StreamReader _sr = null;
    string _filePath = null;
    int _lineStart = 1;
    int _lineEnd = 1;
    bool _isNextChar = false;
    char _nextChar = '\0';

    public SqlStatementReader(StreamReader sr)
    {
        if (sr == null)
            throw new ArgumentNullException("StreamReader can't be null.");

        if (sr.BaseStream is FileStream)
            _filePath = ((FileStream)sr.BaseStream).Name;

        _sr = sr;
    }

    public SqlStatementReader(StreamReader sr, string filePath)
    {
        if (sr == null)
            throw new ArgumentNullException("StreamReader can't be null.");

        _sr = sr;
        _filePath = filePath;
    }

    public int LineStart { get { return _lineStart; } }
    public int LineEnd { get { return _lineEnd == 1 ? _lineEnd : _lineEnd - 1; } }

    public void LightSyntaxCheck()
    {
        while (ReadStatementInternal(true) != null) ;
    }

    public string ReadStatement()
    {
        for (string s = ReadStatementInternal(false); s != null; s = ReadStatementInternal(false))
        {
            // skip empty
            for (int i = 0; i < s.Length; i++)
            {
                switch (s[i])
                {
                    case ' ': continue;
                    case '\t': continue;
                    case '\r': continue;
                    case '\n': continue;
                    default:
                        return s;
                }
            }
        }
        return null;
    }

    string ReadStatementInternal(bool syntaxCheck)
    {
        if (_isNextChar == false && _sr.EndOfStream)
            return null;

        StringBuilder allLines = new StringBuilder();
        StringBuilder line = new StringBuilder();
        SqlScriptChunkTypes nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
        SqlScriptChunkTypes currentChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
        char ch = '\0';
        int lineCounter = 0;
        int nextLine = 0;
        int currentLine = 0;
        bool nextCharHandled = false;
        bool foundGO;
        int go = 1;

        while (ReadChar(out ch))
        {
            if (nextCharHandled == false)
            {
                currentChunk = nextChunk;
                currentLine = nextLine;

                switch (currentChunk)
                {
                    case SqlScriptChunkTypes.InstructionOrUnquotedIdentifier:

                        if (ch == '[')
                        {
                            currentChunk = nextChunk = SqlScriptChunkTypes.BracketIdentifier;
                            currentLine = nextLine = lineCounter;
                        }
                        else if (ch == '"')
                        {
                            currentChunk = nextChunk = SqlScriptChunkTypes.DblQuotIdentifierOrLiteral;
                            currentLine = nextLine = lineCounter;
                        }
                        else if (ch == '\'')
                        {
                            currentChunk = nextChunk = SqlScriptChunkTypes.QuotIdentifierOrLiteral;
                            currentLine = nextLine = lineCounter;
                        }
                        else if (ch == '-' && (_isNextChar && _nextChar == '-'))
                        {
                            nextCharHandled = true;
                            currentChunk = nextChunk = SqlScriptChunkTypes.CommentLine;
                            currentLine = nextLine = lineCounter;
                        }
                        else if (ch == '/' && (_isNextChar && _nextChar == '*'))
                        {
                            nextCharHandled = true;
                            currentChunk = nextChunk = SqlScriptChunkTypes.CommentMultiline;
                            currentLine = nextLine = lineCounter;
                        }
                        else if (ch == ']')
                        {
                            throw new SqlBadSyntaxException("Incorrect syntax near ']'.", _lineEnd + lineCounter, _filePath);
                        }
                        else if (ch == '*' && (_isNextChar && _nextChar == '/'))
                        {
                            throw new SqlBadSyntaxException("Incorrect syntax near '*'.", _lineEnd + lineCounter, _filePath);
                        }
                        break;

                    case SqlScriptChunkTypes.CommentLine:

                        if (ch == '\r' && (_isNextChar && _nextChar == '\n'))
                        {
                            nextCharHandled = true;
                            currentChunk = nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
                            currentLine = nextLine = lineCounter;
                        }
                        else if (ch == '\n' || ch == '\r')
                        {
                            currentChunk = nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
                            currentLine = nextLine = lineCounter;
                        }
                        break;

                    case SqlScriptChunkTypes.CommentMultiline:

                        if (ch == '*' && (_isNextChar && _nextChar == '/'))
                        {
                            nextCharHandled = true;
                            nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
                            nextLine = lineCounter;
                        }
                        else if (ch == '/' && (_isNextChar && _nextChar == '*'))
                        {
                            throw new SqlBadSyntaxException("Missing end comment mark '*/'.", _lineEnd + currentLine, _filePath);
                        }
                        break;

                    case SqlScriptChunkTypes.BracketIdentifier:

                        if (ch == ']')
                        {
                            nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
                            nextLine = lineCounter;
                        }
                        break;

                    case SqlScriptChunkTypes.DblQuotIdentifierOrLiteral:

                        if (ch == '"')
                        {
                            if (_isNextChar && _nextChar == '"')
                            {
                                nextCharHandled = true;
                            }
                            else
                            {
                                nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
                                nextLine = lineCounter;
                            }
                        }
                        break;

                    case SqlScriptChunkTypes.QuotIdentifierOrLiteral:

                        if (ch == '\'')
                        {
                            if (_isNextChar && _nextChar == '\'')
                            {
                                nextCharHandled = true;
                            }
                            else
                            {
                                nextChunk = SqlScriptChunkTypes.InstructionOrUnquotedIdentifier;
                                nextLine = lineCounter;
                            }
                        }
                        break;
                }
            }
            else
                nextCharHandled = false;

            foundGO = false;
            if (currentChunk == SqlScriptChunkTypes.InstructionOrUnquotedIdentifier || go >= 5 || (go == 4 && currentChunk == SqlScriptChunkTypes.CommentLine))
            {
                // go = 0 - break, 1 - begin of the string, 2 - spaces after begin of the string, 3 - G or g, 4 - O or o, 5 - spaces after GO, 6 - line comment after valid GO
                switch (go)
                {
                    case 0:
                        if (ch == '\r' || ch == '\n')
                            go = 1;
                        break;
                    case 1:
                        if (ch == ' ' || ch == '\t')
                            go = 2;
                        else if (ch == 'G' || ch == 'g')
                            go = 3;
                        else if (ch != '\n' && ch != '\r')
                            go = 0;
                        break;
                    case 2:
                        if (ch == 'G' || ch == 'g')
                            go = 3;
                        else if (ch == '\n' || ch == '\r')
                            go = 1;
                        else if (ch != ' ' && ch != '\t')
                            go = 0;
                        break;
                    case 3:
                        if (ch == 'O' || ch == 'o')
                            go = 4;
                        else if (ch == '\n' || ch == '\r')
                            go = 1;
                        else
                            go = 0;
                        break;
                    case 4:
                        if (ch == '\r' && (_isNextChar && _nextChar == '\n'))
                            go = 5;
                        else if (ch == '\n' || ch == '\r')
                            foundGO = true;
                        else if (ch == ' ' || ch == '\t')
                            go = 5;
                        else if (ch == '-' && (_isNextChar && _nextChar == '-'))
                            go = 6;
                        else
                            go = 0;
                        break;
                    case 5:
                        if (ch == '\r' && (_isNextChar && _nextChar == '\n'))
                            go = 5;
                        else if (ch == '\n' || ch == '\r')
                            foundGO = true;
                        else if (ch == '-' && (_isNextChar && _nextChar == '-'))
                            go = 6;
                        else if (ch != ' ' && ch != '\t')
                            throw new SqlBadSyntaxException("Incorrect syntax was encountered while parsing go.", _lineEnd + lineCounter, _filePath);
                        break;
                    case 6:
                        if (ch == '\r' && (_isNextChar && _nextChar == '\n'))
                            go = 6;
                        else if (ch == '\n' || ch == '\r')
                            foundGO = true;
                        break;
                    default:
                        go = 0;
                        break;
                }
            }
            else
                go = 0;

            if (foundGO)
            {
                if (ch == '\r' || ch == '\n')
                {
                    ++lineCounter;
                }
                // clear GO
                string s = line.Append(ch).ToString();
                for (int i = 0; i < s.Length; i++)
                {
                    switch (s[i])
                    {
                        case ' ': continue;
                        case '\t': continue;
                        case '\r': continue;
                        case '\n': continue;
                        default:
                            _lineStart = _lineEnd;
                            _lineEnd += lineCounter;
                            return allLines.Append(s.Substring(0, i)).ToString();
                    }
                }
                return string.Empty;
            }

            // accumulate by string
            if (ch == '\r' && (_isNextChar == false || _nextChar != '\n'))
            {
                ++lineCounter;
                if (syntaxCheck == false)
                    allLines.Append(line.Append('\r').ToString());
                line.Clear();
            }
            else if (ch == '\n')
            {
                ++lineCounter;
                if (syntaxCheck == false)
                    allLines.Append(line.Append('\n').ToString());
                line.Clear();
            }
            else
            {
                if (syntaxCheck == false)
                    line.Append(ch);
            }
        }

        // this is the end of the stream, return it without GO, if GO exists
        switch (currentChunk)
        {
            case SqlScriptChunkTypes.InstructionOrUnquotedIdentifier:
            case SqlScriptChunkTypes.CommentLine:
                break;
            case SqlScriptChunkTypes.CommentMultiline:
                if (nextChunk != SqlScriptChunkTypes.InstructionOrUnquotedIdentifier)
                    throw new SqlBadSyntaxException("Missing end comment mark '*/'.", _lineEnd + currentLine, _filePath);
                break;
            case SqlScriptChunkTypes.BracketIdentifier:
                if (nextChunk != SqlScriptChunkTypes.InstructionOrUnquotedIdentifier)
                    throw new SqlBadSyntaxException("Unclosed quotation mark [.", _lineEnd + currentLine, _filePath);
                break;
            case SqlScriptChunkTypes.DblQuotIdentifierOrLiteral:
                if (nextChunk != SqlScriptChunkTypes.InstructionOrUnquotedIdentifier)
                    throw new SqlBadSyntaxException("Unclosed quotation mark \".", _lineEnd + currentLine, _filePath);
                break;
            case SqlScriptChunkTypes.QuotIdentifierOrLiteral:
                if (nextChunk != SqlScriptChunkTypes.InstructionOrUnquotedIdentifier)
                    throw new SqlBadSyntaxException("Unclosed quotation mark '.", _lineEnd + currentLine, _filePath);
                break;
        }

        if (go >= 4)
        {
            string s = line.ToString();
            for (int i = 0; i < s.Length; i++)
            {
                switch (s[i])
                {
                    case ' ': continue;
                    case '\t': continue;
                    case '\r': continue;
                    case '\n': continue;
                    default:
                        _lineStart = _lineEnd;
                        _lineEnd += lineCounter + 1;
                        return allLines.Append(s.Substring(0, i)).ToString();
                }
            }
        }

        _lineStart = _lineEnd;
        _lineEnd += lineCounter + 1;
        return allLines.Append(line.ToString()).ToString();
    }

    bool ReadChar(out char ch)
    {
        if (_isNextChar)
        {
            ch = _nextChar;
            if (_sr.EndOfStream)
                _isNextChar = false;
            else
                _nextChar = Convert.ToChar(_sr.Read());
            return true;
        }
        else if (_sr.EndOfStream == false)
        {
            ch = Convert.ToChar(_sr.Read());
            if (_sr.EndOfStream == false)
            {
                _isNextChar = true;
                _nextChar = Convert.ToChar(_sr.Read());
            }
            return true;
        }
        else
        {
            ch = '\0';
            return false;
        }
    }

    public static int ExecuteSqlFile(string filePath, SqlConnection connection, Encoding fileEncoding, int commandTimeout)
    {
        int rowsAffected = 0;
        using (FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read))
        {
            // Simple syntax check (you can comment out these two lines below)
            new SqlStatementReader(new StreamReader(fs, fileEncoding)).LightSyntaxCheck();
            fs.Seek(0L, SeekOrigin.Begin);

            // Read statements without GO
            SqlStatementReader rd = new SqlStatementReader(new StreamReader(fs, fileEncoding));
            string stmt;
            while ((stmt = rd.ReadStatement()) != null)
            {
                using (SqlCommand cmd = connection.CreateCommand())
                {
                    cmd.CommandText = stmt;
                    cmd.CommandTimeout = commandTimeout;
                    int i = cmd.ExecuteNonQuery();
                    if (i > 0)
                        rowsAffected += i;
                }
            }
        }
        return rowsAffected;
    }
}

Mysql password expired. Can't connect

This worked for me:

ALTER USER 'root'@'localhost' IDENTIFIED BY 'yourpassword','root'@'localhost' PASSWORD EXPIRE NEVER;

Clear History and Reload Page on Login/Logout Using Ionic Framework

Reload the page isn't the best approach.

you can handle state change events for reload data without reload the view itself.

read about ionicView life-cycle here:

http://blog.ionic.io/navigating-the-changes/

and handle the event beforeEnter for data reload.

$scope.$on('$ionicView.beforeEnter', function(){
  // Any thing you can think of
});

Enable SQL Server Broker taking too long

Enabling SQL Server Service Broker requires a database lock. Stop the SQL Server Agent and then execute the following:

USE master ;
GO

ALTER DATABASE [MyDatabase] SET ENABLE_BROKER ;
GO

Change [MyDatabase] with the name of your database in question and then start SQL Server Agent.

If you want to see all the databases that have Service Broker enabled or disabled, then query sys.databases, for instance:

SELECT
    name, database_id, is_broker_enabled
FROM sys.databases

Convert base-2 binary number string to int

A recursive Python implementation:

def int2bin(n):
    return int2bin(n >> 1) + [n & 1] if n > 1 else [1] 

Room - Schema export directory is not provided to the annotation processor so we cannot export the schema

@mikejonesguy answer is perfect, just in case you plan to test room migrations (recommended), add the schema location to the source sets.

In your build.gradle file you specify a folder to place these generated schema JSON files. As you update your schema, you’ll end up with several JSON files, one for every version. Make sure you commit every generated file to source control. The next time you increase your version number again, Room will be able to use the JSON file for testing.

build.gradle

android {

    // [...]

    defaultConfig {

        // [...]

        javaCompileOptions {
            annotationProcessorOptions {
                arguments = ["room.schemaLocation": "$projectDir/schemas".toString()]
            }
        }
    }

    // add the schema location to the source sets
    // used by Room, to test migrations
    sourceSets {
        androidTest.assets.srcDirs += files("$projectDir/schemas".toString())
    }

    // [...]
}

How to keep the console window open in Visual C++?

The standard way is cin.get() before your return statement.

int _tmain(int argc, _TCHAR* argv[])
{
    cout << "Hello World";
    cin.get();
    return 0;
}

'dispatch' is not a function when argument to mapToDispatchToProps() in Redux

i am using like this.. its easy to understand first argument is mapStateToProps and second argument is mapDispatchToProps in the end connect with function/class.

const mapStateToProps = (state) => {
  return {
    todos: getVisibleTodos(state.todos, state.visibilityFilter)
  }
}

const mapDispatchToProps = (dispatch) => {
  return {
    onTodoClick: (id) => {
      dispatch(toggleTodo(id))
    }
  }
}

export default connect(mapStateToProps,mapDispatchToProps)(TodoList);

What is the use of hashCode in Java?

hashCode

Whenever you override equals(), you are also expected to override hashCode(). The hash code is used when storing the object as a key in a map.

A hash code is a number that puts instances of a class into a finite number of categories. Imagine that I gave you a deck of cards, and I told you that I was going to ask you for specific cards and I want to get the right card back quickly. You have as long as you want to prepare, but I’m in a big hurry when I start asking for cards. You might make 13 piles of cards: All of the aces in one pile, all the twos in another pile, and so forth. That way, when I ask for the five of hearts, you can just pull the right card out of the four cards in the pile with fives. It is certainly faster than going through the whole deck of 52 cards! You could even make 52 piles if you had enough space on the table.

reference : OCP Oracle Certified Professional Java SE 8 Programmer II

How to check if the docker engine and a docker container are running?

I have a more fleshed out example of using some of the work above in the context of a Gitea container, but it could easily be converted to another container based on the name. Also, you could probably use the docker ps --filter capability to set $GITEA_CONTAINER in a newer system or one without docker-compose in use.

# Set to name or ID of the container to be watched.
GITEA_CONTAINER=$(./bin/docker-compose ps |grep git|cut -f1 -d' ')

# Set timeout to the number of seconds you are willing to wait.
timeout=500; counter=0
# This first echo is important for keeping the output clean and not overwriting the previous line of output.
echo "Waiting for $GITEA_CONTAINER to be ready (${counter}/${timeout})"
#This says that until docker inspect reports the container is in a running state, keep looping.
until [[ $(docker inspect --format '{{json .State.Running}}' $GITEA_CONTAINER) == true ]]; do

  # If we've reached the timeout period, report that and exit to prevent running an infinite loop.
  if [[ $timeout -lt $counter ]]; then
    echo "ERROR: Timed out waiting for $GITEA_CONTAINER to come up."
    exit 1
  fi

  # Every 5 seconds update the status
  if (( $counter % 5 == 0 )); then
    echo -e "\e[1A\e[KWaiting for $GITEA_CONTAINER to be ready (${counter}/${timeout})"
  fi

  # Wait a second and increment the counter
  sleep 1s
  ((counter++))

done

Should C# or C++ be chosen for learning Games Programming (consoles)?

C++ is the lingua franca of the console game industry. For better or worse, you must know it to be a professional console game programmer.

Disabling submit button until all fields have values

I refactored the chosen answer here and improved on it. The chosen answer only works assuming you have one form per page. I solved this for multiple forms on same page (in my case I have 2 modals on same page) and my solution only checks for values on required fields. My solution gracefully degrades if JavaScript is disabled and includes a slick CSS button fade transition.

See working JS fiddle example: https://jsfiddle.net/bno08c44/4/

JS

$(function(){
 function submitState(el) {

    var $form = $(el),
        $requiredInputs = $form.find('input:required'),
        $submit = $form.find('input[type="submit"]');

    $submit.attr('disabled', 'disabled');

    $requiredInputs.keyup(function () {

      $form.data('empty', 'false');

      $requiredInputs.each(function() {
        if ($(this).val() === '') {
          $form.data('empty', 'true');
        }
      });

      if ($form.data('empty') === 'true') {
        $submit.attr('disabled', 'disabled').attr('title', 'fill in all required fields');
      } else {
        $submit.removeAttr('disabled').attr('title', 'click to submit');
      }
    });
  }

  // apply to each form element individually
  submitState('#sign_up_user');
  submitState('#login_user');
});

CSS

input[type="submit"] {
  background: #5cb85c;
  color: #fff;
  transition: background 600ms;
  cursor: pointer;
}

input[type="submit"]:disabled {
  background: #555;
  cursor: not-allowed;
}

HTML

<h4>Sign Up</h4>
<form id="sign_up_user" data-empty="" action="#" method="post">
 <input type="email" name="email" placeholder="Email" required>
 <input type="password" name="password" placeholder="Password" required>
 <input type="password" name="password_confirmation" placeholder="Password Confirmation" required>
 <input type="hidden" name="secret" value="secret">
 <input type="submit" value="signup">
</form>

<h4>Login</h4>
<form id="login_user" data-empty="" action="#" method="post">
 <input type="email" name="email" placeholder="Email" required>
 <input type="password" name="password" placeholder="Password" required>
 <input type="checkbox" name="remember" value="1"> remember me
 <input type="submit" value="signup">
</form>

Adding a column to an existing table in a Rails migration

Sometimes rails generate migration add_email_to_users email:string produces a migration like this

class AddEmailToUsers < ActiveRecord::Migration[5.0]
  def change
  end
end

In that case you have to manually an add_column to change:

class AddEmailToUsers < ActiveRecord::Migration[5.0]
  def change
    add_column :users, :email, :string
  end
end

And then run rake db:migrate

How can I debug a Perl script?

If you want to do remote debugging (for CGI or if you don't want to mess output with debug command line), use this:

Given test:

use v5.14;
say 1;
say 2;
say 3;

Start a listener on whatever host and port on terminal 1 (here localhost:12345):

$ nc -v -l localhost -p 12345

For readline support use rlwrap (you can use on perl -d too):

$ rlwrap nc -v -l localhost -p 12345

And start the test on another terminal (say terminal 2):

$ PERLDB_OPTS="RemotePort=localhost:12345" perl -d test

Input/Output on terminal 1:

Connection from 127.0.0.1:42994

Loading DB routines from perl5db.pl version 1.49
Editor support available.

Enter h or 'h h' for help, or 'man perldebug' for more help.

main::(test:2):    say 1;
  DB<1> n
main::(test:3):    say 2;
  DB<1> select $DB::OUT

  DB<2> n
2
main::(test:4):    say 3;
  DB<2> n
3
Debugged program terminated.  Use q to quit or R to restart,
use o inhibit_exit to avoid stopping after program termination,
h q, h R or h o to get additional info.
  DB<2>

Output on terminal 2:

1

Note the sentence if you want output on debug terminal

select $DB::OUT

If you are Vim user, install this plugin: dbg.vim which provides basic support for Perl.

What is the use of "assert"?

The assert statement has two forms.

The simple form, assert <expression>, is equivalent to

if __?debug__:
    if not <expression>: raise AssertionError

The extended form, assert <expression1>, <expression2>, is equivalent to

if __?debug__:
    if not <expression1>: raise AssertionError, <expression2>

Generate Json schema from XML schema (XSD)

Disclaimer: I am the author of Jsonix, a powerful open-source XML<->JSON JavaScript mapping library.

Today I've released the new version of the Jsonix Schema Compiler, with the new JSON Schema generation feature.

Let's take the Purchase Order schema for example. Here's a fragment:

  <xsd:element name="purchaseOrder" type="PurchaseOrderType"/>

  <xsd:complexType name="PurchaseOrderType">
    <xsd:sequence>
      <xsd:element name="shipTo" type="USAddress"/>
      <xsd:element name="billTo" type="USAddress"/>
      <xsd:element ref="comment" minOccurs="0"/>
      <xsd:element name="items"  type="Items"/>
    </xsd:sequence>
    <xsd:attribute name="orderDate" type="xsd:date"/>
  </xsd:complexType>

You can compile this schema using the provided command-line tool:

java -jar jsonix-schema-compiler-full.jar
    -generateJsonSchema
    -p PO
    schemas/purchaseorder.xsd

The compiler generates Jsonix mappings as well the matching JSON Schema.

Here's what the result looks like (edited for brevity):

{
    "id":"PurchaseOrder.jsonschema#",
    "definitions":{
        "PurchaseOrderType":{
            "type":"object",
            "title":"PurchaseOrderType",
            "properties":{
                "shipTo":{
                    "title":"shipTo",
                    "allOf":[
                        {
                            "$ref":"#/definitions/USAddress"
                        }
                    ]
                },
                "billTo":{
                    "title":"billTo",
                    "allOf":[
                        {
                            "$ref":"#/definitions/USAddress"
                        }
                    ]
                }, ...
            }
        },
        "USAddress":{ ... }, ...
    },
    "anyOf":[
        {
            "type":"object",
            "properties":{
                "name":{
                    "$ref":"http://www.jsonix.org/jsonschemas/w3c/2001/XMLSchema.jsonschema#/definitions/QName"
                },
                "value":{
                    "$ref":"#/definitions/PurchaseOrderType"
                }
            },
            "elementName":{
                "localPart":"purchaseOrder",
                "namespaceURI":""
            }
        }
    ]
}

Now this JSON Schema is derived from the original XML Schema. It is not exactly 1:1 transformation, but very very close.

The generated JSON Schema matches the generatd Jsonix mappings. So if you use Jsonix for XML<->JSON conversion, you should be able to validate JSON with the generated JSON Schema. It also contains all the required metadata from the originating XML Schema (like element, attribute and type names).

Disclaimer: At the moment this is a new and experimental feature. There are certain known limitations and missing functionality. But I'm expecting this to manifest and mature very fast.

Links:

pandas create new column based on values from other columns / apply a function of multiple columns, row-wise

try this,

df.loc[df['eri_white']==1,'race_label'] = 'White'
df.loc[df['eri_hawaiian']==1,'race_label'] = 'Haw/Pac Isl.'
df.loc[df['eri_afr_amer']==1,'race_label'] = 'Black/AA'
df.loc[df['eri_asian']==1,'race_label'] = 'Asian'
df.loc[df['eri_nat_amer']==1,'race_label'] = 'A/I AK Native'
df.loc[(df['eri_afr_amer'] + df['eri_asian'] + df['eri_hawaiian'] + df['eri_nat_amer'] + df['eri_white']) > 1,'race_label'] = 'Two Or More'
df.loc[df['eri_hispanic']==1,'race_label'] = 'Hispanic'
df['race_label'].fillna('Other', inplace=True)

O/P:

     lname   fname rno_cd  eri_afr_amer  eri_asian  eri_hawaiian  \
0      MOST    JEFF      E             0          0             0   
1    CRUISE     TOM      E             0          0             0   
2      DEPP  JOHNNY    NaN             0          0             0   
3     DICAP     LEO    NaN             0          0             0   
4    BRANDO  MARLON      E             0          0             0   
5     HANKS     TOM    NaN             0          0             0   
6    DENIRO  ROBERT      E             0          1             0   
7    PACINO      AL      E             0          0             0   
8  WILLIAMS   ROBIN      E             0          0             1   
9  EASTWOOD   CLINT      E             0          0             0   

   eri_hispanic  eri_nat_amer  eri_white rno_defined    race_label  
0             0             0          1       White         White  
1             1             0          0       White      Hispanic  
2             0             0          1     Unknown         White  
3             0             0          1     Unknown         White  
4             0             0          0       White         Other  
5             0             0          1     Unknown         White  
6             0             0          1       White   Two Or More  
7             0             0          1       White         White  
8             0             0          0       White  Haw/Pac Isl.  
9             0             0          1       White         White 

use .loc instead of apply.

it improves vectorization.

.loc works in simple manner, mask rows based on the condition, apply values to the freeze rows.

for more details visit, .loc docs

Performance metrics:

Accepted Answer:

def label_race (row):
   if row['eri_hispanic'] == 1 :
      return 'Hispanic'
   if row['eri_afr_amer'] + row['eri_asian'] + row['eri_hawaiian'] + row['eri_nat_amer'] + row['eri_white'] > 1 :
      return 'Two Or More'
   if row['eri_nat_amer'] == 1 :
      return 'A/I AK Native'
   if row['eri_asian'] == 1:
      return 'Asian'
   if row['eri_afr_amer']  == 1:
      return 'Black/AA'
   if row['eri_hawaiian'] == 1:
      return 'Haw/Pac Isl.'
   if row['eri_white'] == 1:
      return 'White'
   return 'Other'

df=pd.read_csv('dataser.csv')
df = pd.concat([df]*1000)

%timeit df.apply(lambda row: label_race(row), axis=1)

1.15 s ± 46.5 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

My Proposed Answer:

def label_race(df):
    df.loc[df['eri_white']==1,'race_label'] = 'White'
    df.loc[df['eri_hawaiian']==1,'race_label'] = 'Haw/Pac Isl.'
    df.loc[df['eri_afr_amer']==1,'race_label'] = 'Black/AA'
    df.loc[df['eri_asian']==1,'race_label'] = 'Asian'
    df.loc[df['eri_nat_amer']==1,'race_label'] = 'A/I AK Native'
    df.loc[(df['eri_afr_amer'] + df['eri_asian'] + df['eri_hawaiian'] + df['eri_nat_amer'] + df['eri_white']) > 1,'race_label'] = 'Two Or More'
    df.loc[df['eri_hispanic']==1,'race_label'] = 'Hispanic'
    df['race_label'].fillna('Other', inplace=True)
df=pd.read_csv('s22.csv')
df = pd.concat([df]*1000)

%timeit label_race(df)

24.7 ms ± 1.7 ms per loop (mean ± std. dev. of 7 runs, 10 loops each)

Prevent WebView from displaying "web page not available"

Finally, I solved this. (It works till now..)

My solution is like this...

  1. Prepare the layout to show when an error occurred instead of Web Page (a dirty 'page not found message') The layout has one button, "RELOAD" with some guide messages.

  2. If an error occurred, Remember using boolean and show the layout we prepare.

  3. If user click "RELOAD" button, set mbErrorOccured to false. And Set mbReloadPressed to true.
  4. if mbErrorOccured is false and mbReloadPressed is true, it means webview loaded page successfully. 'Cause if error occurred again, mbErrorOccured will be set true on onReceivedError(...)

Here is my full source. Check this out.

public class MyWebViewActivity extends ActionBarActivity implements OnClickListener {

    private final String TAG = MyWebViewActivity.class.getSimpleName();
    private WebView mWebView = null;
    private final String URL = "http://www.google.com";
    private LinearLayout mlLayoutRequestError = null;
    private Handler mhErrorLayoutHide = null;

    private boolean mbErrorOccured = false;
    private boolean mbReloadPressed = false;

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_webview);

        ((Button) findViewById(R.id.btnRetry)).setOnClickListener(this);
        mlLayoutRequestError = (LinearLayout) findViewById(R.id.lLayoutRequestError);
        mhErrorLayoutHide = getErrorLayoutHideHandler();

        mWebView = (WebView) findViewById(R.id.webviewMain);
        mWebView.setWebViewClient(new MyWebViewClient());
        WebSettings settings = mWebView.getSettings();
        settings.setJavaScriptEnabled(true);
        mWebView.setWebChromeClient(getChromeClient());
        mWebView.loadUrl(URL);
    }

    @Override
    public boolean onSupportNavigateUp() {
        return super.onSupportNavigateUp();
    }

    @Override
    public void onClick(View v) {
        int id = v.getId();

        if (id == R.id.btnRetry) {
            if (!mbErrorOccured) {
                return;
            }

            mbReloadPressed = true;
            mWebView.reload();
            mbErrorOccured = false;
        }
    }

    @Override
    public void onBackPressed() {
        if (mWebView.canGoBack()) {
            mWebView.goBack();
            return;
        }
        else {
            finish();
        }

        super.onBackPressed();
    }

    class MyWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return super.shouldOverrideUrlLoading(view, url);
        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
        }

        @Override
        public void onLoadResource(WebView view, String url) {
            super.onLoadResource(view, url);
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            if (mbErrorOccured == false && mbReloadPressed) {
                hideErrorLayout();
                mbReloadPressed = false;
            }

            super.onPageFinished(view, url);
        }

        @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            mbErrorOccured = true;
            showErrorLayout();
            super.onReceivedError(view, errorCode, description, failingUrl);
        }
    }

    private WebChromeClient getChromeClient() {
        final ProgressDialog progressDialog = new ProgressDialog(MyWebViewActivity.this);
        progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        progressDialog.setCancelable(false);

        return new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                super.onProgressChanged(view, newProgress);
            }
        };
    }

    private void showErrorLayout() {
        mlLayoutRequestError.setVisibility(View.VISIBLE);
    }

    private void hideErrorLayout() {
        mhErrorLayoutHide.sendEmptyMessageDelayed(10000, 200);
    }

    private Handler getErrorLayoutHideHandler() {
        return new Handler() {
            @Override
            public void handleMessage(Message msg) {
                mlLayoutRequestError.setVisibility(View.GONE);
                super.handleMessage(msg);
            }
        };
    }
}

Addition:Here is layout....

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rLayoutWithWebView"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<WebView
    android:id="@+id/webviewMain"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<LinearLayout
    android:id="@+id/lLayoutRequestError"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_centerInParent="true"
    android:background="@color/white"
    android:gravity="center"
    android:orientation="vertical"
    android:visibility="gone" >

    <Button
        android:id="@+id/btnRetry"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:minWidth="120dp"
        android:text="RELOAD"
        android:textSize="20dp"
        android:textStyle="bold" />
</LinearLayout>

No module named 'pymysql'

fwiw, for a conda env:

 conda install -c anaconda pymysql 

Declaring functions in JSP?

You need to enclose that in <%! %> as follows:

<%!

public String getQuarter(int i){
String quarter;
switch(i){
        case 1: quarter = "Winter";
        break;

        case 2: quarter = "Spring";
        break;

        case 3: quarter = "Summer I";
        break;

        case 4: quarter = "Summer II";
        break;

        case 5: quarter = "Fall";
        break;

        default: quarter = "ERROR";
}

return quarter;
}

%>

You can then invoke the function within scriptlets or expressions:

<%
     out.print(getQuarter(4));
%>

or

<%= getQuarter(17) %>

How to override toString() properly in Java?

If you're interested in Unit-Tests, then you can declare a public "ToStringTemplate", and then you can unit test your toString. Even if you don't unit-test it, I think its "cleaner" and uses String.format.

public class Kid {

    public static final String ToStringTemplate = "KidName='%1s', Height='%2s', GregCalendar='%3s'";

    private String kidName;
    private double height;
    private GregorianCalendar gregCalendar;

    public String getKidName() {
        return kidName;
    }

    public void setKidName(String kidName) {
        this.kidName = kidName;
    }

    public double getHeight() {
        return height;
    }

    public void setHeight(double height) {
        this.height = height;
    }

    public GregorianCalendar getGregCalendar() {
        return gregCalendar;
    }

    public void setGregCalendar(GregorianCalendar gregCalendar) {
        this.gregCalendar = gregCalendar;
    }

    public String toString() { 
        return String.format(ToStringTemplate, this.getKidName(), this.getHeight(), this.getGregCalendar());
    } 
}

Now you can unit test by create the Kid, setting the properties, and doing your own string.format on the ToStringTemplate and comparing.

making ToStringTemplate static-final means "ONE VERSION" of the truth, rather than having a "copy" of the template in the unit-test.

How can I find the method that called the current method?

Another approach I have used is to add a parameter to the method in question. For example, instead of void Foo(), use void Foo(string context). Then pass in some unique string that indicates the calling context.

If you only need the caller/context for development, you can remove the param before shipping.

Classpath resource not found when running as jar

when spring boot project running as a jar and need read some file in classpath, I implement it by below code

Resource resource = new ClassPathResource("data.sql");
BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()));
reader.lines().forEach(System.out::println);

How to SUM and SUBTRACT using SQL?

I think this is what you're looking for. NEW_BAL is the sum of QTYs subtracted from the balance:

SELECT   master_table.ORDERNO,
         master_table.ITEM,
         SUM(master_table.QTY),
         stock_bal.BAL_QTY,
         (stock_bal.BAL_QTY - SUM(master_table.QTY)) AS NEW_BAL
FROM     master_table INNER JOIN
         stock_bal ON master_bal.ITEM = stock_bal.ITEM
GROUP BY master_table.ORDERNO,
         master_table.ITEM

If you want to update the item balance with the new balance, use the following:

UPDATE stock_bal
SET    BAL_QTY = BAL_QTY - (SELECT   SUM(QTY)
                            FROM     master_table
                            GROUP BY master_table.ORDERNO,
                                     master_table.ITEM)

This assumes you posted the subtraction backward; it subtracts the quantities in the order from the balance, which makes the most sense without knowing more about your tables. Just swap those two to change it if I was wrong:

(SUM(master_table.QTY) - stock_bal.BAL_QTY) AS NEW_BAL

Stop a youtube video with jquery?

if you have autoplay property in the iframe src it wont help to reload the src attr/prop so you have to replace the autoplay=1 to autoplay=0

  var stopVideo = function(player) {
    var vidSrc = player.prop('src').replace('autoplay=1','autoplay=0');
    player.prop('src', vidSrc);
  };

  stopVideo($('#video'));

Entityframework Join using join method and lambdas

You can find a few examples here:

// Fill the DataSet.
DataSet ds = new DataSet();
ds.Locale = CultureInfo.InvariantCulture;
FillDataSet(ds);

DataTable contacts = ds.Tables["Contact"];
DataTable orders = ds.Tables["SalesOrderHeader"];

var query =
    contacts.AsEnumerable().Join(orders.AsEnumerable(),
    order => order.Field<Int32>("ContactID"),
    contact => contact.Field<Int32>("ContactID"),
    (contact, order) => new
    {
        ContactID = contact.Field<Int32>("ContactID"),
        SalesOrderID = order.Field<Int32>("SalesOrderID"),
        FirstName = contact.Field<string>("FirstName"),
        Lastname = contact.Field<string>("Lastname"),
        TotalDue = order.Field<decimal>("TotalDue")
    });


foreach (var contact_order in query)
{
    Console.WriteLine("ContactID: {0} "
                    + "SalesOrderID: {1} "
                    + "FirstName: {2} "
                    + "Lastname: {3} "
                    + "TotalDue: {4}",
        contact_order.ContactID,
        contact_order.SalesOrderID,
        contact_order.FirstName,
        contact_order.Lastname,
        contact_order.TotalDue);
}

Or just google for 'linq join method syntax'.

I want my android application to be only run in portrait mode?

In Android Manifest File, put attribute for your <activity> that android:screenOrientation="portrait"

How to debug a referenced dll (having pdb)

Step 1: Go to Tools-->Option-->Debugging

Step 2: Uncheck Enable Just My Code

Step 3: Uncheck Require source file exactly match with original Version

Step 4: Uncheck Step over Properties and Operators

Step 5: Go to Project properties-->Debug

Step 6: Check Enable native code debugging

Difference between CLOCK_REALTIME and CLOCK_MONOTONIC?

There's one big difference between CLOCK_REALTIME and MONOTONIC. CLOCK_REALTIME can jump forward or backward according to NTP. By default, NTP allows the clock rate to be speeded up or slowed down by up to 0.05%, but NTP cannot cause the monotonic clock to jump forward or backward.

How to Make Laravel Eloquent "IN" Query?

Syntax:

$data = Model::whereIn('field_name', [1, 2, 3])->get();

Use for Users Model

$usersList = Users::whereIn('id', [1, 2, 3])->get();

Error: Jump to case label

JohannesD's answer is correct, but I feel it isn't entirely clear on an aspect of the problem.

The example he gives declares and initializes the variable i in case 1, and then tries to use it in case 2. His argument is that if the switch went straight to case 2, i would be used without being initialized, and this is why there's a compilation error. At this point, one could think that there would be no problem if variables declared in a case were never used in other cases. For example:

switch(choice) {
    case 1:
        int i = 10; // i is never used outside of this case
        printf("i = %d\n", i);
        break;
    case 2:
        int j = 20; // j is never used outside of this case
        printf("j = %d\n", j);
        break;
}

One could expect this program to compile, since both i and j are used only inside the cases that declare them. Unfortunately, in C++ it doesn't compile: as Ciro Santilli ???? ???? ??? explained, we simply can't jump to case 2:, because this would skip the declaration with initialization of i, and even though case 2 doesn't use i at all, this is still forbidden in C++.

Interestingly, with some adjustments (an #ifdef to #include the appropriate header, and a semicolon after the labels, because labels can only be followed by statements, and declarations do not count as statements in C), this program does compile as C:

// Disable warning issued by MSVC about scanf being deprecated
#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#endif

#ifdef __cplusplus
#include <cstdio>
#else
#include <stdio.h>
#endif

int main() {

    int choice;
    printf("Please enter 1 or 2: ");
    scanf("%d", &choice);

    switch(choice) {
        case 1:
            ;
            int i = 10; // i is never used outside of this case
            printf("i = %d\n", i);
            break;
        case 2:
            ;
            int j = 20; // j is never used outside of this case
            printf("j = %d\n", j);
            break;
    }
}

Thanks to an online compiler like http://rextester.com you can quickly try to compile it either as C or C++, using MSVC, GCC or Clang. As C it always works (just remember to set STDIN!), as C++ no compiler accepts it.

What is cardinality in Databases?

Definition: We have tables in database. In relational database, we have relations among the tables. These relations can be one-to-one, one-to-many or many-to-many. These relations are called 'cardinality'.

Significant of cardinality:

Many relational databases have been designed following stick business rules.When you design the database we define the cardinality based on the business rules. But every objects has its own nature as well.

When you define cardinality among object you have to consider all these things to define the correct cardinality.

How do I set up Vim autoindentation properly for editing Python files?

A simpler option: just uncomment the following part of the configuration (which is originally commented out) in the /etc/vim/vimrc file:

    if has("autocmd")
      filetype plugin indent on
    endif

Open a facebook link by native Facebook app on iOS

swift 3

if let url = URL(string: "fb://profile/<id>") {
        if #available(iOS 10, *) {
            UIApplication.shared.open(url, options: [:],completionHandler: { (success) in
                print("Open fb://profile/<id>: \(success)")
            })
        } else {
            let success = UIApplication.shared.openURL(url)
            print("Open fb://profile/<id>: \(success)")
        }
 }

Generate a random date between two other dates

Get random date between start_date and end_date. If any of them is None, then get random date between today and past 100 years.

class GetRandomDateMixin:
    def get_random_date(self, start_date=None, end_date=None):
        """
        get random date between start_date and end_date.
        If any of them is None, then get random date between
        today and past 100 years.
        :param start_date: datetime obj.
            eg: datetime.datetime(1940, 1, 1).date()
        :param end_date: datetime obj
        :return: random date
        """
        if start_date is None or end_date is None:

            end_date = datetime.datetime.today().date()
            start_date = end_date - datetime.timedelta(
                days=(100 * 365)
            )

        delta = end_date - start_date
        random_days = random.randint(1, delta.days)
        new_date = start_date + datetime.timedelta(
            days=random_days
        )

        return new_date

Service Temporarily Unavailable Magento?

I had the same issue but have not found the maintenance.flag file in my Magento root. I simply deleted cache and sessions files and all worked again.

Numpy matrix to array

If you'd like something a bit more readable, you can do this:

A = np.squeeze(np.asarray(M))

Equivalently, you could also do: A = np.asarray(M).reshape(-1), but that's a bit less easy to read.

How do you represent a JSON array of strings?

Basically yes, JSON is just a javascript literal representation of your value so what you said is correct.

You can find a pretty clear and good explanation of JSON notation on http://json.org/

Nodemailer with Gmail and NodeJS

I found the simplest method, described in this article mentioned in Greg T's answer, was to create an App Password which is available after turning on 2FA for the account.

myaccount.google.com > Sign-in & security > Signing in to Google > App Passwords

This gives you an alternative password for the account, then you just configure nodemailer as a normal SMTP service.

var smtpTransport = nodemailer.createTransport({
    host: "smtp.gmail.com",
    port: 587,
    auth: {
        user: "[email protected]",
        pass: "app password"
    }
});

While Google recommend Oauth2 as the best option, this method is easy and hasn't been mentioned in this question yet.

Extra tip: I also found you can add your app name to the "from" address and GMail does not replace it with just the account email like it does if you try to use another address. ie.

from: 'My Pro App Name <[email protected]>'

What is the purpose of Order By 1 in SQL select statement?

Also see:

http://www.techonthenet.com/sql/order_by.php

For a description of order by. I learned something! :)

I've also used this in the past when I wanted to add an indeterminate number of filters to a sql statement. Sloppy I know, but it worked. :P

PHP Session Destroy on Log Out Button

// logout

if(isset($_GET['logout'])) {
    session_destroy();
    unset($_SESSION['username']);
    header('location:login.php');
}

?>

Hide element by class in pure Javascript

Array.filter( document.getElementsByClassName('appBanner'), function(elem){ elem.style.visibility = 'hidden'; });

Forked @http://jsfiddle.net/QVJXD/

Grant SELECT on multiple tables oracle

If you want to grant to both tables and views try:

SELECT DISTINCT
    || OWNER
    || '.'
    || TABLE_NAME
    || ' to db_user;'
FROM
    ALL_TAB_COLS 
WHERE
    TABLE_NAME LIKE 'TABLE_NAME_%';

For just views try:

SELECT
    'grant select on '
    || OWNER
    || '.'
    || VIEW_NAME
    || ' to REPORT_DW;'
FROM
    ALL_VIEWS
WHERE
    VIEW_NAME LIKE 'VIEW_NAME_%';

Copy results and execute.

What's wrong with foreign keys?

I'm sure there are plenty of applications where you can get away with it, but it's not the best idea. You can't always count on your application to properly manage your database, and frankly managing the database should not be of very much concern to your application.

If you are using a relational database then it seems you ought to have some relationships defined in it. Unfortunately this attitude (you don't need foreign keys) seems to be embraced by a lot of application developers who would rather not be bothered with silly things like data integrity (but need to because their companies don't have dedicated database developers). Usually in databases put together by these types you are lucky just to have primary keys ;)

Java: how do I check if a Date is within a certain range?

For covering my case -> I've got a range start & end date, and dates list that can be as partly in provided range, as fully (overlapping).

Solution covered with tests:

/**
 * Check has any of quote work days in provided range.
 *
 * @param startDate inclusively
 * @param endDate   inclusively
 *
 * @return true if any in provided range inclusively
 */
public boolean hasAnyWorkdaysInRange(LocalDate startDate, LocalDate endDate) {
    if (CollectionUtils.isEmpty(workdays)) {
        return false;
    }

    LocalDate firstWorkDay = getFirstWorkDay().getDate();
    LocalDate lastWorkDay = getLastWorkDay().getDate();

    return (firstWorkDay.isBefore(endDate) || firstWorkDay.equals(endDate))
            && (lastWorkDay.isAfter(startDate) || lastWorkDay.equals(startDate));
}

Microsoft Visual C++ Compiler for Python 3.4

Unfortunately to be able to use the extension modules provided by others you'll be forced to use the official compiler to compile Python. These are:

Alternatively, you can use MinGw to compile extensions in a way that won't depend on others.

See: https://docs.python.org/2/install/#gnu-c-cygwin-MinGW or https://docs.python.org/3.4/install/#gnu-c-cygwin-mingw

This allows you to have one compiler to build your extensions for both versions of Python, Python 2.x and Python 3.x.

Replace all occurrences of a string in a data frame

If you are only looking to replace all occurrences of "< " (with space) with "<" (no space), then you can do an lapply over the data frame, with a gsub for replacement:

> data <- data.frame(lapply(data, function(x) {
+                  gsub("< ", "<", x)
+              }))
> data
  name var1 var2
1    a   <2   <3
2    a   <2   <3
3    a   <2   <3
4    b   <2   <3
5    b   <2   <3
6    b   <2   <3
7    c   <2   <3
8    c   <2   <3
9    c   <2   <3

How to compare dates in c#

If you have your dates in DateTime variables, they don't have a format.

You can use the Date property to return a DateTime value with the time portion set to midnight. So, if you have:

DateTime dt1 = DateTime.Parse("07/12/2011");
DateTime dt2 = DateTime.Now;

if(dt1.Date > dt2.Date)
{
     //It's a later date
}
else
{
     //It's an earlier or equal date
}

Specifying maxlength for multiline textbox

This is the same as @KeithK's answer, but with a few more details. First, create a new control based on TextBox.

using System.Web.UI;
using System.Web.UI.WebControls;

namespace MyProject
{
    public class LimitedMultiLineTextBox : System.Web.UI.WebControls.TextBox
    {
        protected override void Render(HtmlTextWriter writer)
        {
            this.TextMode = TextBoxMode.MultiLine;

            if (this.MaxLength > 0)
            {
                writer.AddAttribute(HtmlTextWriterAttribute.Maxlength, this.MaxLength.ToString());
            }

            base.Render(writer);
        }
    }
}  

Note that the code above always sets the textmode to multiline.

In order to use this, you need to register it on the aspx page. This is required because you'll need to reference it using the TagPrefix, otherwise compilation will complain about custom generic controls.

<%@ Register Assembly="MyProject" Namespace="MyProject" TagPrefix="mp" %>

<mp:LimitedMultiLineTextBox runat="server" Rows="3" ...

css display table cell requires percentage width

You just need to add 'table-layout: fixed;'

.table {
   display: table;
   height: 100px;
   width: 100%;
   table-layout: fixed;
}

http://www.w3schools.com/cssref/pr_tab_table-layout.asp

Identify if a string is a number

You can use TryParse to determine if the string can be parsed into an integer.

int i;
bool bNum = int.TryParse(str, out i);

The boolean will tell you if it worked or not.

Get the last non-empty cell in a column in Google Sheets

Calculate the difference between latest date in column A with the date in cell A2.

=MAX(A2:A)-A2

Modulo operator in Python

same as a normal modulo 3.14 % 6.28 = 3.14, just like 3.14%4 =3.14 3.14%2 = 1.14 (the remainder...)

android.content.res.Resources$NotFoundException: String resource ID Fatal Exception in Main

You tried to do a.setText(a1). a1 is an int value, but setText() requires a string value. For this reason you need use String.valueOf(a1) to pass the value of a1 as a String and not as an int to a.setText(), like so:

a.setText(String.valueOf(a1))

that was the exact solution to the problem with my case.

Access HTTP response as string in Go

string(byteslice) will convert byte slice to string, just know that it's not only simply type conversion, but also memory copy.

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

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

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

Put buttons at bottom of screen with LinearLayout?

Just add layout_weight="1" to in your linearLayout which having Buttons.

Edit :- let me make it simple

follow something like below, tags name may not be correct, it is just an Idea

<LL>// Top Parrent LinearLayout
   <LL1 height="fill_parent" weight="1" "other tags as requirement"> <TV /><Butons /></LL1> // this layout will fill your screen.
   <LL2 height="wrap_content" weight="1"  orientation="Horizontal" "other tags as requirement"> <BT1 /><BT2/ ></LL2> // this layout gonna take lower part of button height of your screen

<LL/> TOP PARENT CLOSED

jQuery post() with serialize and extra data

You can use this

var data = $("#myForm").serialize();
data += '&moreinfo='+JSON.stringify(wordlist);

How to call codeigniter controller function from view

You can call controller function from view in the following way:

Controller:

public function read() {
    $object['controller'] = $this; 
    $this->load->view('read', $object);
}

View:

// to call controller function from view, do
$controller->myOtherFunct();

jQuery: click function exclude children.

Or you can do also:

$('.example').on('click', function(e) { 
   if( e.target != this ) 
       return false;

   // ... //
});

Python: How exactly can you take a string, split it, reverse it and join it back together again?

You mean this?

from string import punctuation, digits

takeout = punctuation + digits

turnthis = "(fjskl) 234 = -345 089 abcdef"
turnthis = turnthis.translate(None, takeout)[::-1]
print turnthis

How to emulate GPS location in the Android Emulator?

If you're using Android Studio (1.3):

  • Click on Menu "Tools"
  • "Android"
  • "Android device monitor"
  • click on your current Emulator
  • Tab "Emulator Control"
  • go to "Location Controls" and enter Lat and Lon

Why I got " cannot be resolved to a type" error?

Maybe wrong path..? Check your .classpath file.

Postgres: check if array field contains value?

This should work:

select * from mytable where 'Journal'=ANY(pub_types);

i.e. the syntax is <value> = ANY ( <array> ). Also notice that string literals in postresql are written with single quotes.

Python Inverse of a Matrix

It is a pity that the chosen matrix, repeated here again, is either singular or badly conditioned:

A = matrix( [[1,2,3],[11,12,13],[21,22,23]])

By definition, the inverse of A when multiplied by the matrix A itself must give a unit matrix. The A chosen in the much praised explanation does not do that. In fact just looking at the inverse gives a clue that the inversion did not work correctly. Look at the magnitude of the individual terms - they are very, very big compared with the terms of the original A matrix...

It is remarkable that the humans when picking an example of a matrix so often manage to pick a singular matrix!

I did have a problem with the solution, so looked into it further. On the ubuntu-kubuntu platform, the debian package numpy does not have the matrix and the linalg sub-packages, so in addition to import of numpy, scipy needs to be imported also.

If the diagonal terms of A are multiplied by a large enough factor, say 2, the matrix will most likely cease to be singular or near singular. So

A = matrix( [[2,2,3],[11,24,13],[21,22,46]])

becomes neither singular nor nearly singular and the example gives meaningful results... When dealing with floating numbers one must be watchful for the effects of inavoidable round off errors.

Thanks for your contribution,

OldAl.

What is the difference between `Enum.name()` and `Enum.toString()`?

The main difference between name() and toString() is that name() is a final method, so it cannot be overridden. The toString() method returns the same value that name() does by default, but toString() can be overridden by subclasses of Enum.

Therefore, if you need the name of the field itself, use name(). If you need a string representation of the value of the field, use toString().

For instance:

public enum WeekDay {
    MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY;

    public String toString() {
        return name().charAt(0) + name().substring(1).toLowerCase();
    }
}

In this example, WeekDay.MONDAY.name() returns "MONDAY", and WeekDay.MONDAY.toString() returns "Monday".

WeekDay.valueOf(WeekDay.MONDAY.name()) returns WeekDay.MONDAY, but WeekDay.valueOf(WeekDay.MONDAY.toString()) throws an IllegalArgumentException.

Call int() function on every list element?

If you are intending on passing those integers to a function or method, consider this example:

sum(int(x) for x in numbers)

This construction is intentionally remarkably similar to list comprehensions mentioned by adamk. Without the square brackets, it's called a generator expression, and is a very memory-efficient way of passing a list of arguments to a method. A good discussion is available here: Generator Expressions vs. List Comprehension

How do I increase memory on Tomcat 7 when running as a Windows Service?

According to catalina.sh customizations should always go into your own setenv.sh (or setenv.bat respectively) eg:

CATALINA_OPTS='-Xms512m -Xmx1024m'

My guess is that setenv.bat will also be called when starting a service.I might be wrong, though, since I'm not a windows user.

instantiate a class from a variable in PHP?

If You Use Namespaces

In my own findings, I think it's good to mention that you (as far as I can tell) must declare the full namespace path of a class.

MyClass.php

namespace com\company\lib;
class MyClass {
}

index.php

namespace com\company\lib;

//Works fine
$i = new MyClass();

$cname = 'MyClass';

//Errors
//$i = new $cname;

//Works fine
$cname = "com\\company\\lib\\".$cname;
$i = new $cname;

Pointers in JavaScript?

You refer to 'x' from window object

var x = 0;

function a(key, ref) {
    ref = ref || window;  // object reference - default window
    ref[key]++;
}

a('x');                   // string
alert(x);

C# int to byte[]

using static System.Console;

namespace IntToBits
{
    class Program
    {
        static void Main()
        {
            while (true)
            {
                string s = Console.ReadLine();
                Clear();
                uint i;
                bool b = UInt32.TryParse(s, out i);
                if (b) IntPrinter(i);
            }
        }

        static void IntPrinter(uint i)
        {
            int[] iarr = new int [32];
            Write("[");
            for (int j = 0; j < 32; j++)
            {
                uint tmp = i & (uint)Math.Pow(2, j);

                iarr[j] = (int)(tmp >> j);
            }
            for (int j = 32; j > 0; j--)
            {
                if(j%8==0 && j != 32)Write("|");
                if(j%4==0 && j%8 !=0) Write("'");
                Write(iarr[j-1]);
            }
            WriteLine("]");
        }
    }
}```

Waiting till the async task finish its work

wait until this call is finish its executing

You will need to call AsyncTask.get() method for getting result back and make wait until doInBackground execution is not complete. but this will freeze Main UI thread if you not call get method inside a Thread.

To get result back in UI Thread start AsyncTask as :

String str_result= new RunInBackGround().execute().get();

How to declare local variables in postgresql?

Postgresql historically doesn't support procedural code at the command level - only within functions. However, in Postgresql 9, support has been added to execute an inline code block that effectively supports something like this, although the syntax is perhaps a bit odd, and there are many restrictions compared to what you can do with SQL Server. Notably, the inline code block can't return a result set, so can't be used for what you outline above.

In general, if you want to write some procedural code and have it return a result, you need to put it inside a function. For example:

CREATE OR REPLACE FUNCTION somefuncname() RETURNS int LANGUAGE plpgsql AS $$
DECLARE
  one int;
  two int;
BEGIN
  one := 1;
  two := 2;
  RETURN one + two;
END
$$;
SELECT somefuncname();

The PostgreSQL wire protocol doesn't, as far as I know, allow for things like a command returning multiple result sets. So you can't simply map T-SQL batches or stored procedures to PostgreSQL functions.

What does the Java assert keyword do, and when should it be used?

Assertions are a development-phase tool to catch bugs in your code. They're designed to be easily removed, so they won't exist in production code. So assertions are not part of the "solution" that you deliver to the customer. They're internal checks to make sure that the assumptions you're making are correct. The most common example is to test for null. Many methods are written like this:

void doSomething(Widget widget) {
  if (widget != null) {
    widget.someMethod(); // ...
    ... // do more stuff with this widget
  }
}

Very often in a method like this, the widget should simply never be null. So if it's null, there's a bug in your code somewhere that you need to track down. But the code above will never tell you this. So in a well-intentioned effort to write "safe" code, you're also hiding a bug. It's much better to write code like this:

/**
 * @param Widget widget Should never be null
 */
void doSomething(Widget widget) {
  assert widget != null;
  widget.someMethod(); // ...
    ... // do more stuff with this widget
}

This way, you will be sure to catch this bug early. (It's also useful to specify in the contract that this parameter should never be null.) Be sure to turn assertions on when you test your code during development. (And persuading your colleagues to do this, too is often difficult, which I find very annoying.)

Now, some of your colleagues will object to this code, arguing that you should still put in the null check to prevent an exception in production. In that case, the assertion is still useful. You can write it like this:

void doSomething(Widget widget) {
  assert widget != null;
  if (widget != null) {
    widget.someMethod(); // ...
    ... // do more stuff with this widget
  }
}

This way, your colleagues will be happy that the null check is there for production code, but during development, you're no longer hiding the bug when widget is null.

Here's a real-world example: I once wrote a method that compared two arbitrary values for equality, where either value could be null:

/**
 * Compare two values using equals(), after checking for null.
 * @param thisValue (may be null)
 * @param otherValue (may be null)
 * @return True if they are both null or if equals() returns true
 */
public static boolean compare(final Object thisValue, final Object otherValue) {
  boolean result;
  if (thisValue == null) {
    result = otherValue == null;
  } else {
    result = thisValue.equals(otherValue);
  }
  return result;
}

This code delegates the work of the equals() method in the case where thisValue is not null. But it assumes the equals() method correctly fulfills the contract of equals() by properly handling a null parameter.

A colleague objected to my code, telling me that many of our classes have buggy equals() methods that don't test for null, so I should put that check into this method. It's debatable if this is wise, or if we should force the error, so we can spot it and fix it, but I deferred to my colleague and put in a null check, which I've marked with a comment:

public static boolean compare(final Object thisValue, final Object otherValue) {
  boolean result;
  if (thisValue == null) {
    result = otherValue == null;
  } else {
    result = otherValue != null && thisValue.equals(otherValue); // questionable null check
  }
  return result;
}

The additional check here, other != null, is only necessary if the equals() method fails to check for null as required by its contract.

Rather than engage in a fruitless debate with my colleague about the wisdom of letting the buggy code stay in our code base, I simply put two assertions in the code. These assertions will let me know, during the development phase, if one of our classes fails to implement equals() properly, so I can fix it:

public static boolean compare(final Object thisValue, final Object otherValue) {
  boolean result;
  if (thisValue == null) {
    result = otherValue == null;
    assert otherValue == null || otherValue.equals(null) == false;
  } else {
    result = otherValue != null && thisValue.equals(otherValue);
    assert thisValue.equals(null) == false;
  }
  return result;
}

The important points to keep in mind are these:

  1. Assertions are development-phase tools only.

  2. The point of an assertion is to let you know if there's a bug, not just in your code, but in your code base. (The assertions here will actually flag bugs in other classes.)

  3. Even if my colleague was confident that our classes were properly written, the assertions here would still be useful. New classes will be added that might fail to test for null, and this method can flag those bugs for us.

  4. In development, you should always turn assertions on, even if the code you've written doesn't use assertions. My IDE is set to always do this by default for any new executable.

  5. The assertions don't change the behavior of the code in production, so my colleague is happy that the null check is there, and that this method will execute properly even if the equals() method is buggy. I'm happy because I will catch any buggy equals() method in development.

Also, you should test your assertion policy by putting in a temporary assertion that will fail, so you can be certain that you are notified, either through the log file or a stack trace in the output stream.

Check if two unordered lists are equal

If elements are always nearly sorted as in your example then builtin .sort() (timsort) should be fast:

>>> a = [1,1,2]
>>> b = [1,2,2]
>>> a.sort()
>>> b.sort()
>>> a == b
False

If you don't want to sort inplace you could use sorted().

In practice it might always be faster then collections.Counter() (despite asymptotically O(n) time being better then O(n*log(n)) for .sort()). Measure it; If it is important.

Iterating a JavaScript object's properties using jQuery

$.each( { name: "John", lang: "JS" }, function(i, n){
    alert( "Name: " + i + ", Value: " + n );
});

each

How does DISTINCT work when using JPA and Hibernate

@Entity
@NamedQuery(name = "Customer.listUniqueNames", 
            query = "SELECT DISTINCT c.name FROM Customer c")
public class Customer {
        ...

        private String name;

        public static List<String> listUniqueNames() {
             return = getEntityManager().createNamedQuery(
                   "Customer.listUniqueNames", String.class)
                   .getResultList();
        }
}

SVN Repository on Google Drive or DropBox

Here's one application that works for me. In our case...I wanted the Sales team to use SVN for certain docs (Price sheets and such)...but a bit over there head.

I setup an Auto SVN like this: - Created a REPO in my SVN server. - Checked out repo into a DB folder call AutoSVN. - I run EasySVN on my PC, which auto commits and updates the REPO.

With he 'Auto', there are no log comments, but not critical for these particular docs.

The Sales guys use the DB folder...and simply maintain the file name of those docs that need version control such as price sheets.

How to run cron job every 2 hours

0 */1 * * * “At minute 0 past every hour.”

0 */2 * * * “At minute 0 past every 2nd hour.”

This is the proper way to set cronjobs for every hr.

Import txt file and having each line as a list

with open('path/to/file') as infile: # try open('...', 'rb') as well
    answer = [line.strip().split(',') for line in infile]

If you want the numbers as ints:

with open('path/to/file') as infile:
    answer = [[int(i) for i in line.strip().split(',')] for line in infile]

How to close Browser Tab After Submitting a Form?

Remove onsubmit from the form tag. Change this:

<input type="submit" value="submit" />

To:

<input type="submit" value="submit" name='btnSub' />

And write this:

if(isset($_POST['btnSub']))
    echo "<script>window.close();</script>";

how to rotate a bitmap 90 degrees

By default the rotation point is the Canvas's (0,0) point, and my guess is that you may want to rotate it around the center. I did that:

protected void renderImage(Canvas canvas)
{
    Rect dest,drawRect ;

    drawRect = new Rect(0,0, mImage.getWidth(), mImage.getHeight());
    dest = new Rect((int) (canvas.getWidth() / 2 - mImage.getWidth() * mImageResize / 2), // left
                    (int) (canvas.getHeight()/ 2 - mImage.getHeight()* mImageResize / 2), // top
                    (int) (canvas.getWidth() / 2 + mImage.getWidth() * mImageResize / 2), //right
                    (int) (canvas.getWidth() / 2 + mImage.getHeight()* mImageResize / 2));// bottom

    if(!mRotate) {
        canvas.drawBitmap(mImage, drawRect, dest, null);
    } else {
        canvas.save(Canvas.MATRIX_SAVE_FLAG); //Saving the canvas and later restoring it so only this image will be rotated.
        canvas.rotate(90,canvas.getWidth() / 2, canvas.getHeight()/ 2);
        canvas.drawBitmap(mImage, drawRect, dest, null);
        canvas.restore();
    }
}

SQL like search string starts with

SELECT * from games WHERE (lower(title) LIKE 'age of empires III');

The above query doesn't return any rows because you're looking for 'age of empires III' exact string which doesn't exists in any rows.

So in order to match with this string with different string which has 'age of empires' as substring you need to use '%your string goes here%'

More on mysql string comparision

You need to try this

SELECT * from games WHERE (lower(title) LIKE '%age of empires III%');

In Like '%age of empires III%' this will search for any matching substring in your rows, and it will show in results.

LISTAGG in Oracle to return distinct values

To get around the string length issue you can use XMLAGG which is similar to listagg but it returns a clob.

You can can then parse using regexp_replace and get the unique values and then turn it back into a string using dbms_lob.substr(). If you have a huge amount of distinct values you will still run out of space this way but for a lot of cases the code below should work.

You can also change the delimiters you use. In my case I wanted '-' instead of ',' but you should be able to replace the dashes in my code and use commas if you want that.

select col1,
    dbms_lob.substr(ltrim(REGEXP_REPLACE(REPLACE(
         REPLACE(
           XMLAGG(
             XMLELEMENT("A",col2)
               ORDER BY col2).getClobVal(),
             '<A>','-'),
             '</A>',''),'([^-]*)(-\1)+($|-)', 
           '\1\3'),'-'), 4000,1) as platform_mix
from table

phpMyAdmin allow remote users

Just comment all lines in first Directory. Or you can remove these lines, but better to keep in case later you want to add some restrictions, you will uncomment.

#<Directory /usr/share/phpMyAdmin/>
#   <IfModule mod_authz_core.c>
#     # Apache 2.4
#     <RequireAny>
#       Require ip 127.0.0.1
#       Require ip ::1
#     </RequireAny>
#   </IfModule>
#   <IfModule !mod_authz_core.c>
#     # Apache 2.2
#     Order Deny,Allow
#     Deny from All
#     Allow from 127.0.0.1
#     Allow from ::1
#   </IfModule>
#</Directory>

Android Studio is slow (how to speed up)?

Click Help > Edit Custom properties and add this line:

sun.java2d.noddraw=false

... worked successfully for me to fix the speed issues (Windows 10 64-bit). It's absolute voodoo as far as I'm concerned (I haven't done any research on why that should work), and there is a warning above that property that it can cause blinking and fail to repaint on some graphics cards, but there you go. (Inspired by LairdPleng's comment, further information)

Get file size, image width and height before upload

As far as I know there is not an easy way to do this since Javascript/JQuery does not have access to the local filesystem. There are some new features in html 5 that allows you to check certain meta data such as file size but I'm not sure if you can actually get the image dimensions.

Here is an article I found regarding the html 5 features, and a work around for IE that involves using an ActiveX control. http://jquerybyexample.blogspot.com/2012/03/how-to-check-file-size-before-uploading.html

Passing HTML input value as a JavaScript Function Parameter

1 IDs are meant to be unique

2 You dont need to pass any argument as you can call them in your javascript

<form>
  a: <input type="number" name="a" id="a"><br>
  b: <input type="number" name="b" id="b"><br>
  <button onclick="add()">Add</button>
</form>
<script>
  function add() {
    var a = document.getElementById('a').value;
    var b = document.getElementById('b').value;
    var sum = a + b;
    alert(sum);
  }
</script>

Java Multiple Inheritance

Technically speaking, you can only extend one class at a time and implement multiple interfaces, but when laying hands on software engineering, I would rather suggest a problem specific solution not generally answerable. By the way, it is good OO practice, not to extend concrete classes/only extend abstract classes to prevent unwanted inheritance behavior - there is no such thing as an "animal" and no use of an animal object but only concrete animals.

How to use SearchView in Toolbar Android

Integrating SearchView with RecyclerView

1) Add SearchView Item in Menu

SearchView can be added as actionView in menu using

app:useActionClass = "android.support.v7.widget.SearchView" .

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="rohksin.com.searchviewdemo.MainActivity">
<item
    android:id="@+id/searchBar"
    app:showAsAction="always"
    app:actionViewClass="android.support.v7.widget.SearchView"
    />
</menu>

2) Implement SearchView.OnQueryTextListener in your Activity

SearchView.OnQueryTextListener has two abstract methods. So your activity skeleton would now look like this after implementing SearchView text listener.

YourActivity extends AppCompatActivity implements SearchView.OnQueryTextListener{

   public boolean onQueryTextSubmit(String query)

   public boolean onQueryTextChange(String newText) 

}

3) Set up SerchView Hint text, listener etc

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);

    MenuItem searchItem = menu.findItem(R.id.searchBar);

    SearchView searchView = (SearchView) searchItem.getActionView();
    searchView.setQueryHint("Search People");
    searchView.setOnQueryTextListener(this);
    searchView.setIconified(false);

    return true;
}

4) Implement SearchView.OnQueryTextListener

This is how you can implement abstract methods of the listener.

@Override
public boolean onQueryTextSubmit(String query) {

    // This method can be used when a query is submitted eg. creating search history using SQLite DB

    Toast.makeText(this, "Query Inserted", Toast.LENGTH_SHORT).show();
    return true;
}

@Override
public boolean onQueryTextChange(String newText) {

    adapter.filter(newText);
    return true;
}

5) Write a filter method in your RecyclerView Adapter.

You can come up with your own logic based on your requirement. Here is the sample code snippet to show the list of Name which contains the text typed in the SearchView.

public void filter(String queryText)
{
    list.clear();

    if(queryText.isEmpty())
    {
        list.addAll(copyList);
    }
    else
    {

        for(String name: copyList)
        {
            if(name.toLowerCase().contains(queryText.toLowerCase()))
            {
                list.add(name);
            }
        }

    }

    notifyDataSetChanged();
}

Full working code sample can be found > HERE
You can also check out the code on SearchView with an SQLite database in this Music App

Difference between "git add -A" and "git add ."

It's useful to have descriptions of what each flag does. By using a CLI like bit you'll have access to flag descriptions as you're typing.

How do files get into the External Dependencies in Visual Studio C++?

The External Dependencies folder is populated by IntelliSense: the contents of the folder do not affect the build at all (you can in fact disable the folder in the UI).

You need to actually include the header (using a #include directive) to use it. Depending on what that header is, you may also need to add its containing folder to the "Additional Include Directories" property and you may need to add additional libraries and library folders to the linker options; you can set all of these in the project properties (right click the project, select Properties). You should compare the properties with those of the project that does build to determine what you need to add.

Edit a commit message in SourceTree Windows (already pushed to remote)

On Version 1.9.6.1. For UnPushed commit.

  1. Click on previously committed description
  2. Click Commit icon
  3. Enter new commit message, and choose "Ammend latest commit" from the Commit options dropdown.
  4. Commit your message.

How do you remove the title text from the Android ActionBar?

Simply extends your java file from AppCompatActivity and do this:

ActionBar actionBar = getSupportActionBar(); // support.v7
actionBar.setTitle(" ");

#pragma pack effect

Data elements (e.g. members of classes and structs) are typically aligned on WORD or DWORD boundaries for current generation processors in order to improve access times. Retrieving a DWORD at an address which isn't divisible by 4 requires at least one extra CPU cycle on a 32 bit processor. So, if you have e.g. three char members char a, b, c;, they actually tend to take 6 or 12 bytes of storage.

#pragma allows you to override this to achieve more efficient space usage, at the expense of access speed, or for consistency of stored data between different compiler targets. I had a lot of fun with this transitioning from 16 bit to 32 bit code; I expect porting to 64 bit code will cause the same kinds of headaches for some code.

python pip: force install ignoring dependencies

pip has a --no-dependencies switch. You should use that.

For more information, run pip install -h, where you'll see this line:

--no-deps, --no-dependencies
                        Ignore package dependencies

How can I compare two lists in python and return matches

I just used the following and it worked for me:

group1 = [1, 2, 3, 4, 5]
group2 = [9, 8, 7, 6, 5]

for k in group1:
    for v in group2:
        if k == v:
            print(k)

this would then print 5 in your case. Probably not great performance wise though.

Could not insert new outlet connection: Could not find any information for the class named

None of the tips in the best answer worked for me. Was going crazy. Then noticed that the Assistant Editor had somehow gotten set to Manual and I was on the ViewController.swift (Interface) instead of the ViewController.swift file.

Changed that and problem solved. A bit embarrassing but hey, we are all learning.

enter image description here

How do you debug MySQL stored procedures?

How to debug a MySQL stored procedure.

Poor mans debugger:

  1. Create a table called logtable with two columns, id INT and log VARCHAR(255).

  2. Make the id column autoincrement.

  3. Use this procedure:

    delimiter //
    DROP PROCEDURE `log_msg`//
    CREATE PROCEDURE `log_msg`(msg VARCHAR(255))
    BEGIN
        insert into logtable select 0, msg;
    END
    
  4. Put this code anywhere you want to log a message to the table.

    call log_msg(concat('myvar is: ', myvar, ' and myvar2 is: ', myvar2));
    

It's a nice quick and dirty little logger to figure out what is going on.

Changing CSS for last <li>

I usually combine CSS and JavaScript approaches, so that it works without JavaScript in all browsers but IE6/7, and in IE6/7 with JavaScript on (but not off), since they does not support the :last-child pseudo-class.

$("li:last-child").addClass("last-child");

li:last-child,li.last-child{ /* ... */ }

how to create 100% vertical line in css

There are at least two ways to solve this.

Solution 1:

If you are okay with using an absolutely positioned element, you can use the top and bottom properties instead of height. By setting both top and bottom to 0 you force the element into taking up full height.

#menu
{
    position: absolute;
    border-right: 1px solid black;
    top: 0;
    bottom: 0;
}?

Demo

Solution 2:

Another way would be to force the HTML and BODY elements into a 100% height, to give room for a menu with 100% height:

body, html { height: 100%; }
#menu
{
    border-right: 1px solid black;
    height: 100%;
}?

Demo

Best way to repeat a character in C#

How about this:

//Repeats a character specified number of times
public static string Repeat(char character,int numberOfIterations)
{
    return "".PadLeft(numberOfIterations, character);
}

//Call the Repeat method
Console.WriteLine(Repeat('\t',40));

Hibernate: ids for this class must be manually assigned before calling save()

your id attribute is not set. this MAY be due to the fact that the DB field is not set to auto increment? what DB are you using? MySQL? is your field set to AUTO INCREMENT?

load and execute order of scripts

The browser will execute the scripts in the order it finds them. If you call an external script, it will block the page until the script has been loaded and executed.

To test this fact:

// file: test.php
sleep(10);
die("alert('Done!');");

// HTML file:
<script type="text/javascript" src="test.php"></script>

Dynamically added scripts are executed as soon as they are appended to the document.

To test this fact:

<!DOCTYPE HTML>
<html>
<head>
    <title>Test</title>
</head>
<body>
    <script type="text/javascript">
        var s = document.createElement('script');
        s.type = "text/javascript";
        s.src = "link.js"; // file contains alert("hello!");
        document.body.appendChild(s);
        alert("appended");
    </script>
    <script type="text/javascript">
        alert("final");
    </script>
</body>
</html>

Order of alerts is "appended" -> "hello!" -> "final"

If in a script you attempt to access an element that hasn't been reached yet (example: <script>do something with #blah</script><div id="blah"></div>) then you will get an error.

Overall, yes you can include external scripts and then access their functions and variables, but only if you exit the current <script> tag and start a new one.

Vertical alignment of text and icon in button

There is one rule that is set by font-awesome.css, which you need to override.

You should set overrides in your CSS files rather than inline, but essentially, the icon-ok class is being set to vertical-align: baseline; by default and which I've corrected here:

<button id="whatever" class="btn btn-large btn-primary" name="Continue" type="submit">
    <span>Continue</span>
    <i class="icon-ok" style="font-size:30px; vertical-align: middle;"></i>
</button>

Example here: http://jsfiddle.net/fPXFY/4/ and the output of which is:

enter image description here

I've downsized the font-size of the icon above in this instance to 30px, as it feels too big at 40px for the size of the button, but this is purely a personal viewpoint. You could increase the padding on the button to compensate if required:

<button id="whaever" class="btn btn-large btn-primary" style="padding: 20px;" name="Continue" type="submit">
    <span>Continue</span>
    <i class="icon-ok" style="font-size:30px; vertical-align: middle;"></i>
</button>

Producing: http://jsfiddle.net/fPXFY/5/ the output of which is:

enter image description here

SQL Developer is returning only the date, not the time. How do I fix this?

Can you try this?

Go to Tools> Preferences > Database > NLS and set the Date Format as MM/DD/YYYY HH24:MI:SS

Difference between acceptance test and functional test?

In my world, we use the terms as follows:

functional testing: This is a verification activity; did we build a correctly working product? Does the software meet the business requirements?

For this type of testing we have test cases that cover all the possible scenarios we can think of, even if that scenario is unlikely to exist "in the real world". When doing this type of testing, we aim for maximum code coverage. We use any test environment we can grab at the time, it doesn't have to be "production" caliber, so long as it's usable.

acceptance testing: This is a validation activity; did we build the right thing? Is this what the customer really needs?

This is usually done in cooperation with the customer, or by an internal customer proxy (product owner). For this type of testing we use test cases that cover the typical scenarios under which we expect the software to be used. This test must be conducted in a "production-like" environment, on hardware that is the same as, or close to, what a customer will use. This is when we test our "ilities":

  • Reliability, Availability: Validated via a stress test.

  • Scalability: Validated via a load test.

  • Usability: Validated via an inspection and demonstration to the customer. Is the UI configured to their liking? Did we put the customer branding in all the right places? Do we have all the fields/screens they asked for?

  • Security (aka, Securability, just to fit in): Validated via demonstration. Sometimes a customer will hire an outside firm to do a security audit and/or intrusion testing.

  • Maintainability: Validated via demonstration of how we will deliver software updates/patches.

  • Configurability: Validated via demonstration of how the customer can modify the system to suit their needs.

This is by no means standard, and I don't think there is a "standard" definition, as the conflicting answers here demonstrate. The most important thing for your organization is that you define these terms precisely, and stick to them.

Compare a date string to datetime in SQL Server?

In SQL Server 2008, you could use the new DATE datatype

DECLARE @pDate DATE='2008-08-14'  

SELECT colA, colB
FROM table1
WHERE convert(date, colDateTime) = @pDate  

@Guy. I think you will find that this solution scales just fine. Have a look at the query execution plan of your original query.

And for mine:

Why is IoC / DI not common in Python?

Part of it is the way the module system works in Python. You can get a sort of "singleton" for free, just by importing it from a module. Define an actual instance of an object in a module, and then any client code can import it and actually get a working, fully constructed / populated object.

This is in contrast to Java, where you don't import actual instances of objects. This means you are always having to instantiate them yourself, (or use some sort of IoC/DI style approach). You can mitigate the hassle of having to instantiate everything yourself by having static factory methods (or actual factory classes), but then you still incur the resource overhead of actually creating new ones each time.

Why does Eclipse complain about @Override on interface methods?

Even after changing the compiler compliance setting to 1.6 or 1.7 from windows tab, then prefernces, then java, then compiler and setting the compiler compliance, I was still having this issue. The idea is that we need to go the the project folder, right click, Java and set compiler compliance to 1.6 or higer. This worked for me.

css transform, jagged edges in chrome

Try 3d transform. This works like a charm!

/* Due to a bug in the anti-liasing*/
-webkit-transform-style: preserve-3d; 
-webkit-transform: rotateZ(2deg);

CodeIgniter: Unable to connect to your database server using the provided settings Error Message

I solved the problem by changing

$db['default']['pconnect'] = TRUE; TO $db['default']['pconnect'] = FALSE;

in /application/config/database.php

angular.service vs angular.factory

app.factory('fn', fn) vs. app.service('fn',fn)

Construction

With factories, Angular will invoke the function to get the result. It is the result that is cached and injected.

 //factory
 var obj = fn();
 return obj;

With services, Angular will invoke the constructor function by calling new. The constructed function is cached and injected.

  //service
  var obj = new fn();
  return obj;

Implementation

Factories typically return an object literal because the return value is what's injected into controllers, run blocks, directives, etc

  app.factory('fn', function(){
         var foo = 0;
         var bar = 0;
         function setFoo(val) {
               foo = val;
         }
         function setBar (val){
               bar = val;
         }
         return {
                setFoo: setFoo,
                serBar: setBar
         }
  });

Service functions typically do not return anything. Instead, they perform initialization and expose functions. Functions can also reference 'this' since it was constructed using 'new'.

app.service('fn', function () {
         var foo = 0;
         var bar = 0;
         this.setFoo = function (val) {
               foo = val;
         }
         this.setBar = function (val){
               bar = val;
         }
});

Conclusion

When it comes to using factories or services they are both very similar. They are injected into a controllers, directives, run block, etc, and used in client code in pretty much the same way. They are also both singletons - meaning the same instance is shared between all places where the service/factory is injected.

So which should you prefer? Either one - they are so similar that the differences are trivial. If you do choose one over the other, just be aware how they are constructed, so that you can implement them properly.

Git: Find the most recent common ancestor of two branches

You are looking for git merge-base. Usage:

$ git merge-base branch2 branch3
050dc022f3a65bdc78d97e2b1ac9b595a924c3f2

disable horizontal scroll on mobile web

I've found this answer over here on stackoverflow which works perfectly for me:

use this in style

body {
    overflow-x: hidden;
    width: 100%;
}

Use this in head tag

<meta name="viewport" content="user-scalable=no, width=device-width, initial-scale=1.0" />
<meta name="apple-mobile-web-app-capable" content="yes" />

A slight addition of mine in case your body has padding (to prevent the device from scaling to the body content-box, and thus still adding a horizontal scrollbar):

body {
    overflow-x: hidden;
    width: 100%;
    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;
}

how to make label visible/invisible?

You should be able to get it to hide/show by setting:

.style.display = 'none';
.style.display = 'inline';

How to put an image next to each other

try putting both images next to each other. Like this:

    <div id="icons"><a href="http://www.facebook.com/"><img src="images/facebook.png"></a><a href="https://twitter.com"><img src="images/twitter.png"></a>
    </div>

How to include a sub-view in Blade templates?

EDIT: Below was the preferred solution in 2014. Nowadays you should use @include, as mentioned in the other answer.


In Laravel views the dot is used as folder separator. So for example I have this code

return View::make('auth.details', array('id' => $id));

which points to app/views/auth/details.blade.php

And to include a view inside a view you do like this:

file: layout.blade.php

<html>
  <html stuff>
  @yield('content')
</html>

file: hello.blade.php

@extends('layout')

@section('content')
  <html stuff>
@stop

Why does 2 mod 4 = 2?

I think you are getting confused over how the modulo equation is read.

When we write a division equation such as 2/4 we are dividing 2 by 4.

When a modulo equation is wrote such as 2 % 4 we are dividing 2 by 4 (think 2 over 4) and returning the remainder.

Android: No Activity found to handle Intent error? How it will resolve

in my case, i was sure that the action is correct, but i was passing wrong URL, i passed the website link without the http:// in it's beginning, so it caused the same issue, here is my manifest (part of it)

<activity
        android:name=".MyBrowser"
        android:label="MyBrowser Activity" >
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <action android:name="com.dsociety.activities.MyBrowser" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:scheme="http" />
        </intent-filter>
    </activity>

when i code the following, the same Exception is thrown at run time :

Intent intent = new Intent();
intent.setAction("com.dsociety.activities.MyBrowser");
intent.setData(Uri.parse("www.google.com"));    // should be http://www.google.com
startActivity(intent);

Strings as Primary Keys in SQL Database

By default ASPNetUserIds are 128 char strings and performance is just fine.

If the key HAS to be unique in the table it should be the Key. Here's why;

primary string key = Correct DB relationships, 1 string key(The primary), and 1 string Index(The Primary).

The other option is a typical int Key, but if the string HAS to be unique you'll still probably need to add an index because of non-stop queries to validate or check that its unique.

So using an int identity key = Incorrect DB Relationships, 1 int key(Primary), 1 int index(Primary), Probably a unique string Index, and manually having to validate the same string doesn't exist(something like a sql check maybe).

To get better performance using an int over a string for the primary key, when the string HAS to be unique, it would have to be a very odd situation. I've always preferred to use string keys. And as a good rule of thumb, don't denormalize a database until you NEED to.

Missing Push Notification Entitlement

This happened to me suddenly because my app's distribution profile had expired. Xcode began using the wildcard profile instead, which did not have the push notification entitlement enabled. I didn't receive any warning. The fix was easy; I just had to generate another distribution profile for my app in the Apple Developer Member Center, download it, and double-click to install in Xcode.

apache mod_rewrite is not working or not enabled

On centOS7 I changed the file /etc/httpd/conf/httpd.conf

from AllowOverride None to AllowOverride All

Display open transactions in MySQL

How can I display these open transactions and commit or cancel them?

There is no open transaction, MySQL will rollback the transaction upon disconnect.
You cannot commit the transaction (IFAIK).

You display threads using

SHOW FULL PROCESSLIST  

See: http://dev.mysql.com/doc/refman/5.1/en/thread-information.html

It will not help you, because you cannot commit a transaction from a broken connection.

What happens when a connection breaks
From the MySQL docs: http://dev.mysql.com/doc/refman/5.0/en/mysql-tips.html

4.5.1.6.3. Disabling mysql Auto-Reconnect

If the mysql client loses its connection to the server while sending a statement, it immediately and automatically tries to reconnect once to the server and send the statement again. However, even if mysql succeeds in reconnecting, your first connection has ended and all your previous session objects and settings are lost: temporary tables, the autocommit mode, and user-defined and session variables. Also, any current transaction rolls back.

This behavior may be dangerous for you, as in the following example where the server was shut down and restarted between the first and second statements without you knowing it:

Also see: http://dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html

How to diagnose and fix this
To check for auto-reconnection:

If an automatic reconnection does occur (for example, as a result of calling mysql_ping()), there is no explicit indication of it. To check for reconnection, call mysql_thread_id() to get the original connection identifier before calling mysql_ping(), then call mysql_thread_id() again to see whether the identifier has changed.

Make sure you keep your last query (transaction) in the client so that you can resubmit it if need be.
And disable auto-reconnect mode, because that is dangerous, implement your own reconnect instead, so that you know when a drop occurs and you can resubmit that query.

Deprecated meaning?

Deprecated in general means "don't use it".
A deprecated function may or may not work, but it is not guaranteed to work.

How to add form validation pattern in Angular 2?

Now, you don't need to use FormBuilder and all this complicated valiation angular stuff. I put more details from this (Angular 2.0.8 - 3march2016): https://github.com/angular/angular/commit/38cb526

Example from repo :

<input [ngControl]="fullName" pattern="[a-zA-Z ]*">

I test it and it works :) - here is my code:

<form (ngSubmit)="onSubmit(room)" #roomForm='ngForm'  >
...
<input 
  id='room-capacity' 
  type="text" 
  class="form-control" 
  [(ngModel)]='room.capacity' 
  ngControl="capacity" 
  required
  pattern="[0-9]+" 
  #capacity='ngForm'>

Alternative approach (UPDATE June 2017)

Validation is ONLY on server side. If something is wrong then server return error code e.g HTTP 400 and following json object in response body (as example):

this.err = { 
    "capacity" : "too_small"
    "filed_name" : "error_name", 
    "field2_name" : "other_error_name",
    ... 
}

In html template I use separate tag (div/span/small etc.)

<input [(ngModel)]='room.capacity' ...>
<small *ngIf="err.capacity" ...>{{ translate(err.capacity) }}</small>

If in 'capacity' is error then tag with msg translation will be visible. This approach have following advantages:

  • it is very simple
  • avoid backend validation code duplication on frontend (for regexp validation this can either prevent or complicate ReDoS attacks)
  • control on way the error is shown (e.g. <small> tag)
  • backend return error_name which is easy to translate to proper language in frontend

Of course sometimes I make exception if validation is needed on frontend side (e.g. retypePassword field on registration is never send to server).

Exception in thread "main" java.util.NoSuchElementException

simply don't close in

remove in.close() from your code.

How can I protect my .NET assemblies from decompilation?

We use {SmartAssembly} for .NET protection of an enterprise level distributed application, and it has worked great for us.

Where to download Microsoft Visual c++ 2003 redistributable

Storm's answer is not correct. No hard feelings Storm, and apologies to the OP as I'm a bit late to the party here (wish I could have helped sooner, but I didn't run into the problem until today, or this stack overflow answer until I was figuring out a solution.)

The Visual C++ 2003 runtime was not available as a seperate download because it was included with the .NET 1.1 runtime.

If you install the .NET 1.1 runtime you will get msvcr71.dll installed, and in addition added to C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322.

The .NET 1.1 runtime is available here: http://www.microsoft.com/downloads/en/details.aspx?familyid=262d25e3-f589-4842-8157-034d1e7cf3a3&displaylang=en (23.1 MB)

If you are looking for a file that ends with a "P" such as msvcp71.dll, this indicates that your file was compiled against a C++ runtime (as opposed to a C runtime), in some situations I noticed these files were only installed when I installed the full SDK. If you need one of these files, you may need to install the full .NET 1.1 SDK as well, which is available here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=9b3a2ca6-3647-4070-9f41-a333c6b9181d (106.2 MB)

After installing the SDK I now have both msvcr71.dll and msvcp71.dll in my System32 folder, and the application I'm trying to run (boomerang c++ decompiler) works fine without any missing DLL errors.

Also on a side note: be VERY aware of the difference between a Hotfix Update and a Regular Update. As noted in the linked KB932298 download (linked below by Storm): "Please be aware this Hotfix has not gone through full Microsoft product regression testing nor has it been tested in combination with other Hotfixes."

Hotfixes are NOT meant for general users, but rather users who are facing a very specific problem. As described in the article only install that Hotfix if you are have having specific daylight savings time issues with the rules that changed in 2007. -- Likely this was a pre-release for customers who "just couldn't wait" for the official update (probably for some business critical application) -- for regular users Windows Update should be all you need.

Thanks, and I hope this helps others who run into this issue!

How to pass the id of an element that triggers an `onclick` event to the event handling function

Here's a non-standard but cross-browser method that may be useful if you don't want to pass any arguments:-

Html:

<div onclick=myHandler() id="my element's id">&rarr; Click Here! &larr;</div>

Script:

function myHandler(){
    alert(myHandler.caller.arguments[0].target.id)
}

Demo: http://codepen.io/mrmoje/pen/ouJtk

How to get std::vector pointer to the raw data?

Take a pointer to the first element instead:

process_data (&something [0]);

What is "Advanced" SQL?

I suppose subqueries and PIVOT would qualify, as well as multiple joins, unions and the like.

Char array to hex string C++

You can try this code for converting bytes from packet to a null-terminated string and store to "string" variable for processing.

const int buffer_size = 2048;
// variable for storing buffer as printable HEX string
char data[buffer_size*2];
// receive message from socket
int ret = recvfrom(sock, buffer, sizeofbuffer, 0, reinterpret_cast<SOCKADDR *>(&from), &size);
// bytes converting cycle
for (int i=0,j=0; i<ret; i++,j+=2){ 
    char res[2]; 
    itoa((buffer[i] & 0xFF), res, 16);
        if (res[1] == 0) {
            data[j] = 0x30; data[j+1] = res[0];
        }else {
            data[j] = res[0]; data[j + 1] = res[1];
        }
}
// Null-Terminating the string with converted buffer
data[(ret * 2)] = 0;

When we send message with hex bytes 0x01020E0F, variable "data" had char array with string "01020e0f".

SQL Server dynamic PIVOT query?

There's my solution cleaning up the unnecesary null values

DECLARE @cols AS NVARCHAR(MAX),
@maxcols AS NVARCHAR(MAX),
@query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT ',' + QUOTENAME(CodigoFormaPago) 
                from PO_FormasPago
                order by CodigoFormaPago
        FOR XML PATH(''), TYPE
        ).value('.', 'NVARCHAR(MAX)') 
    ,1,1,'')

select @maxcols = STUFF((SELECT ',MAX(' + QUOTENAME(CodigoFormaPago) + ') as ' + QUOTENAME(CodigoFormaPago)
                from PO_FormasPago
                order by CodigoFormaPago
        FOR XML PATH(''), TYPE
        ).value('.', 'NVARCHAR(MAX)')
    ,1,1,'')

set @query = 'SELECT CodigoProducto, DenominacionProducto, ' + @maxcols + '
            FROM
            (
                SELECT 
                CodigoProducto, DenominacionProducto,
                ' + @cols + ' from 
                 (
                    SELECT 
                        p.CodigoProducto as CodigoProducto,
                        p.DenominacionProducto as DenominacionProducto,
                        fpp.CantidadCuotas as CantidadCuotas,
                        fpp.IdFormaPago as IdFormaPago,
                        fp.CodigoFormaPago as CodigoFormaPago
                    FROM
                        PR_Producto p
                        LEFT JOIN PR_FormasPagoProducto fpp
                            ON fpp.IdProducto = p.IdProducto
                        LEFT JOIN PO_FormasPago fp
                            ON fpp.IdFormaPago = fp.IdFormaPago
                ) xp
                pivot 
                (
                    MAX(CantidadCuotas)
                    for CodigoFormaPago in (' + @cols + ')
                ) p 
            )  xx 
            GROUP BY CodigoProducto, DenominacionProducto'

t @query;

execute(@query);

What's the difference between HTML 'hidden' and 'aria-hidden' attributes?

A hidden attribute is a boolean attribute (True/False). When this attribute is used on an element, it removes all relevance to that element. When a user views the html page, elements with the hidden attribute should not be visible.

Example:

    <p hidden>You can't see this</p>

Aria-hidden attributes indicate that the element and ALL of its descendants are still visible in the browser, but will be invisible to accessibility tools, such as screen readers.

Example:

    <p aria-hidden="true">You can't see this</p>

Take a look at this. It should answer all your questions.

Note: ARIA stands for Accessible Rich Internet Applications

Sources: Paciello Group

Bash: Echoing a echo command with a variable in bash

The immediate problem is you have is with quoting: by using double quotes ("..."), your variable references are instantly expanded, which is probably not what you want.

Use single quotes instead - strings inside single quotes are not expanded or interpreted in any way by the shell.

(If you want selective expansion inside a string - i.e., expand some variable references, but not others - do use double quotes, but prefix the $ of references you do not want expanded with \; e.g., \$var).

However, you're better off using a single here-doc[ument], which allows you to create multi-line stdin input on the spot, bracketed by two instances of a self-chosen delimiter, the opening one prefixed by <<, and the closing one on a line by itself - starting at the very first column; search for Here Documents in man bash or at http://www.gnu.org/software/bash/manual/html_node/Redirections.html.

If you quote the here-doc delimiter (EOF in the code below), variable references are also not expanded. As @chepner points out, you're free to choose the method of quoting in this case: enclose the delimiter in single quotes or double quotes, or even simply arbitrarily escape one character in the delimiter with \:

echo "creating new script file."

cat <<'EOF'  > "$servfile"
#!/bin/bash
read -p "Please enter a service: " ser
servicetest=`getsebool -a | grep ${ser}` 
if [ $servicetest > /dev/null ]; then 
  echo "we are now going to work with ${ser}"
else
  exit 1
fi
EOF

As @BruceK notes, you can prefix your here-doc delimiter with - (applied to this example: <<-"EOF") in order to have leading tabs stripped, allowing for indentation that makes the actual content of the here-doc easier to discern. Note, however, that this only works with actual tab characters, not leading spaces.

Employing this technique combined with the afterthoughts regarding the script's content below, we get (again, note that actual tab chars. must be used to lead each here-doc content line for them to get stripped):

cat <<-'EOF' > "$servfile"
    #!/bin/bash
    read -p "Please enter a service name: " ser
    if [[ -n $(getsebool -a | grep "${ser}") ]]; then 
      echo "We are now going to work with ${ser}."
    else
      exit 1
    fi
EOF

Finally, note that in bash even normal single- or double-quoted strings can span multiple lines, but you won't get the benefits of tab-stripping or line-block scoping, as everything inside the quotes becomes part of the string.

Thus, note how in the following #!/bin/bash has to follow the opening ' immediately in order to become the first line of output:

echo '#!/bin/bash
read -p "Please enter a service: " ser
servicetest=$(getsebool -a | grep "${ser}")
if [[ -n $servicetest ]]; then 
  echo "we are now going to work with ${ser}"
else
  exit 1
fi' > "$servfile"

Afterthoughts regarding the contents of your script:

  • The syntax $(...) is preferred over `...` for command substitution nowadays.
  • You should double-quote ${ser} in the grep command, as the command will likely break if the value contains embedded spaces (alternatively, make sure that the valued read contains no spaces or other shell metacharacters).
  • Use [[ -n $servicetest ]] to test whether $servicetest is empty (or perform the command substitution directly inside the conditional) - [[ ... ]] - the preferred form in bash - protects you from breaking the conditional if the $servicetest happens to have embedded spaces; there's NEVER a need to suppress stdout output inside a conditional (whether [ ... ] or [[ ... ]], as no stdout output is passed through; thus, the > /dev/null is redundant (that said, with a command substitution inside a conditional, stderr output IS passed through).

Using FileUtils in eclipse

FileUtils is class from apache org.apache.commons.io package, you need to download org.apache.commons.io.jar and then configure that jar file in your class path.

Running AMP (apache mysql php) on Android

I think this is what you're looking for: PAW Server from http://paw-android.fun2code.de/

hope it works

What is C# analog of C++ std::pair?

Depending on what you want to accomplish, you might want to try out KeyValuePair.

The fact that you cannot change the key of an entry can of course be rectified by simply replacing the entire entry by a new instance of KeyValuePair.

await vs Task.Wait - Deadlock?

Some important facts were not given in other answers:

"async await" is more complex at CIL level and thus costs memory and CPU time.

Any task can be canceled if the waiting time is unacceptable.

In the case "async await" we do not have a handler for such a task to cancel it or monitoring it.

Using Task is more flexible then "async await".

Any sync functionality can by wrapped by async.

public async Task<ActionResult> DoAsync(long id) 
{ 
    return await Task.Run(() => { return DoSync(id); } ); 
} 

"async await" generate many problems. We do not now is await statement will be reached without runtime and context debugging. If first await not reached everything is blocked. Some times even await seems to be reached still everything is blocked:

https://github.com/dotnet/runtime/issues/36063

I do not see why I'm must live with the code duplication for sync and async method or using hacks.

Conclusion: Create Task manually and control them is much better. Handler to Task give more control. We can monitor Tasks and manage them:

https://github.com/lsmolinski/MonitoredQueueBackgroundWorkItem

Sorry for my english.

Reversing a linked list in Java, recursively

Inspired by an article discussing immutable implementations of recursive data structures I put an alternate solution together using Swift.

The leading answer documents solution by highlighting the following topics:

  1. What is the reverse of nil (the empty list)?
    • Does not matter here, because we have nil protection in Swift.
  2. What is the reverse of a one element list?
    • The element itself
  3. What is the reverse of an n element list?
    • The reverse of the second element on followed by the first element.

I have called these out where applicable in the solution below.

/**
 Node is a class that stores an arbitrary value of generic type T 
 and a pointer to another Node of the same time.  This is a recursive 
 data structure representative of a member of a unidirectional linked
 list.
 */
public class Node<T> {
    public let value: T
    public let next: Node<T>?

    public init(value: T, next: Node<T>?) {
        self.value = value
        self.next = next
    }

    public func reversedList() -> Node<T> {
        if let next = self.next {
            // 3. The reverse of the second element on followed by the first element.
            return next.reversedList() + value
        } else {
            // 2. Reverse of a one element list is itself
            return self
        }
    }
}

/**
 @return Returns a newly created Node consisting of the lhs list appended with rhs value.
 */
public func +<T>(lhs: Node<T>, rhs: T) -> Node<T> {
    let tail: Node<T>?
    if let next = lhs.next {
        // The new tail is created recursively, as long as there is a next node.
        tail = next + rhs
    } else {
        // If there is not a next node, create a new tail node to append
        tail = Node<T>(value: rhs, next: nil)
    }
    // Return a newly created Node consisting of the lhs list appended with rhs value.
    return Node<T>(value: lhs.value, next: tail)
}

How does the vim "write with sudo" trick work?

I'd like to suggest another approach to the "Oups I forgot to write sudo while opening my file" issue:

Instead of receiving a permission denied, and having to type :w!!, I find it more elegant to have a conditional vim command that does sudo vim if file owner is root.

This is as easy to implement (there might even be more elegant implementations, I'm clearly not a bash-guru):

function vim(){
  OWNER=$(stat -c '%U' $1)
  if [[ "$OWNER" == "root" ]]; then
    sudo /usr/bin/vim $*;
  else
    /usr/bin/vim $*;
  fi
}

And it works really well.

This is a more bash-centered approach than a vim-one so not everybody might like it.

Of course:

  • there are use cases where it will fail (when file owner is not root but requires sudo, but the function can be edited anyway)
  • it doesn't make sense when using vim for reading-only a file (as far as I'm concerned, I use tail or cat for small files)

But I find this brings a much better dev user experience, which is something that IMHO tends to be forgotten when using bash. :-)

How to commit a change with both "message" and "description" from the command line?

In case you want to improve the commit message with header and body after you created the commit, you can reword it. This approach is more useful because you know what the code does only after you wrote it.

git rebase -i origin/master

Then, your commits will appear:

pick e152ce2 Update framework
pick ffcf91e Some magic
pick fa672e1 Update comments

Select the commit you want to reword and save.

pick e152ce2 Update framework
reword ffcf91e Some magic
pick fa672e1 Update comments

Now, you have the opportunity to add header and body, where the first line will be the header.

Create perpetuum mobile

Redesign laws of physics with a pinch of imagination. Open a wormhole in 23 dimensions. Add protection to avoid high instability.

How do you round a number to two decimal places in C#?

  public double RoundDown(double number, int decimalPlaces)
        {
            return Math.Floor(number * Math.Pow(10, decimalPlaces)) / Math.Pow(10, decimalPlaces);
        }

Ruby's File.open gives "No such file or directory - text.txt (Errno::ENOENT)" error

Ditto Casper's answer:

puts Dir.pwd

As soon as you know current working directory, specify the file path relatively to that directory.

For example, if your working directory is project root, you can open a file under it directly like this

json_file = File.read(myfile.json)

Is there a better jQuery solution to this.form.submit();?

Similar to Matthew's answer, I just found that you can do the following:

$(this).closest('form').submit();

Wrong: The problem with using the parent functionality is that the field needs to be immediately within the form to work (not inside tds, labels, etc).

I stand corrected: parents (with an s) also works. Thxs Paolo for pointing that out.

Adobe Acrobat Pro make all pages the same dimension

The page sizes are looking different in your PDF because the images were originally set to different DPI (even if images are identical HxW in pixels). The good news is - it's only a display issue - and can be fixed easily.

An image with a higher DPI value would display smaller in a PDF (displays at the 'print-size' of the image). To avoid this, open each image in an image editor like GIMP or Photoshop. Open relevant image print control dialog box and set a suitable uniform DPI info for all the images. Remake the PDF with these new images. If in the new PDF images are too big - redo the DPI setting for each to a higher value. If in the new PDF pages are too small to read on-screen without zooming, again - redo DPI adjustment, this time put a lower DPI value. Ideally, 150 DPI should be good enough for images of 2500X2500 pixel - on a 17 inch monitor set to 1366x768 resolution.

BTW, the PDF file shall print each page at the specified DPI of that page. If all images are same DPI, you'll get a uniform printing.

Hope this helps :)

Python: most idiomatic way to convert None to empty string?

Variation on the above if you need to be compatible with Python 2.4

xstr = lambda s: s is not None and s or ''

How to delete rows from a pandas DataFrame based on a conditional expression

In pandas you can do str.len with your boundary and using the Boolean result to filter it .

df[df['column name'].str.len().lt(2)]

Update records using LINQ

Just as an addition to the accepted answer, you might find your code looking more consistent when using the LINQ method syntax:

Context.person_account_portfolio
.Where(p => person_id == personId)
.ToList()
.ForEach(x => x.is_default = false);

.ToList() is neccessary because .ForEach() is defined only on List<T>, not on IEnumerable<T>. Just be aware .ToList() is going to execute the query and load ALL matching rows from database before executing the loop.

Can I call methods in constructor in Java?

The constructor is called only once, so you can safely do what you want, however the disadvantage of calling methods from within the constructor, rather than directly, is that you don't get direct feedback if the method fails. This gets more difficult the more methods you call.

One solution is to provide methods that you can call to query the 'health' of the object once it's been constructed. For example the method isConfigOK() can be used to see if the config read operation was OK.

Another solution is to throw exceptions in the constructor upon failure, but it really depends on how 'fatal' these failures are.

class A
{
    Map <String,String> config = null;
    public A()
    {
        readConfig();
    }

    protected boolean readConfig()
    {
        ...
    }

    public boolean isConfigOK()
    {
        // Check config here
        return true;
    }
};