Programs & Examples On #Hbase

HBase is the Hadoop database (columnar). Use it when you need random, real time read/write access to your Big Data. This project's goal is the hosting of very large tables -- billions of rows X millions of columns -- atop clusters of commodity hardware.

Hbase quickly count number of rows

You can use coprocessor what is available since HBase 0.92. See Coprocessor and AggregateProtocol and example

When to use Hadoop, HBase, Hive and Pig?

Understanding in depth

Hadoop

Hadoop is an open source project of the Apache foundation. It is a framework written in Java, originally developed by Doug Cutting in 2005. It was created to support distribution for Nutch, the text search engine. Hadoop uses Google's Map Reduce and Google File System Technologies as its foundation.

Features of Hadoop

  1. It is optimized to handle massive quantities of structured, semi-structured and unstructured data using commodity hardware.
  2. It has shared nothing architecture.
  3. It replicates its data into multiple computers so that if one goes down, the data can still be processed from another machine that stores its replica.
  4. Hadoop is for high throughput rather than low latency. It is a batch operation handling massive quantities of data; therefore the response time is not immediate.
  5. It complements Online Transaction Processing and Online Analytical Processing. However, it is not a replacement for a RDBMS.
  6. It is not good when work cannot be parallelized or when there are dependencies within the data.
  7. It is not good for processing small files. It works best with huge data files and data sets.

Versions of Hadoop

There are two versions of Hadoop available :

  1. Hadoop 1.0
  2. Hadoop 2.0

Hadoop 1.0

It has two main parts :

1. Data Storage Framework

It is a general-purpose file system called Hadoop Distributed File System (HDFS).

HDFS is schema-less

It simply stores data files and these data files can be in just about any format.

The idea is to store files as close to their original form as possible.

This in turn provides the business units and the organization the much needed flexibility and agility without being overly worried by what it can implement.

2. Data Processing Framework

This is a simple functional programming model initially popularized by Google as MapReduce.

It essentially uses two functions: MAP and REDUCE to process data.

The "Mappers" take in a set of key-value pairs and generate intermediate data (which is another list of key-value pairs).

The "Reducers" then act on this input to produce the output data.

The two functions seemingly work in isolation with one another, thus enabling the processing to be highly distributed in highly parallel, fault-tolerance and scalable way.

Limitations of Hadoop 1.0

  1. The first limitation was the requirement of MapReduce programming expertise.

  2. It supported only batch processing which although is suitable for tasks such as log analysis, large scale data mining projects but pretty much unsuitable for other kinds of projects.

  3. One major limitation was that Hadoop 1.0 was tightly computationally coupled with MapReduce, which meant that the established data management vendors where left with two opinions:

    1. Either rewrite their functionality in MapReduce so that it could be executed in Hadoop or

    2. Extract data from HDFS or process it outside of Hadoop.

None of the options were viable as it led to process inefficiencies caused by data being moved in and out of the Hadoop cluster.

Hadoop 2.0

In Hadoop 2.0, HDFS continues to be data storage framework.

However, a new and seperate resource management framework called Yet Another Resource Negotiater (YARN) has been added.

Any application capable of dividing itself into parallel tasks is supported by YARN.

YARN coordinates the allocation of subtasks of the submitted application, thereby further enhancing the flexibility, scalability and efficiency of applications.

It works by having an Application Master in place of Job Tracker, running applications on resources governed by new Node Manager.

ApplicationMaster is able to run any application and not just MapReduce.

This means it does not only support batch processing but also real-time processing. MapReduce is no longer the only data processing option.

Advantages of Hadoop

It stores data in its native from. There is no structure imposed while keying in data or storing data. HDFS is schema less. It is only later when the data needs to be processed that the structure is imposed on the raw data.

It is scalable. Hadoop can store and distribute very large datasets across hundreds of inexpensive servers that operate in parallel.

It is resilient to failure. Hadoop is fault tolerance. It practices replication of data diligently which means whenever data is sent to any node, the same data also gets replicated to other nodes in the cluster, thereby ensuring that in event of node failure,there will always be another copy of data available for use.

It is flexible. One of the key advantages of Hadoop is that it can work with any kind of data: structured, unstructured or semi-structured. Also, the processing is extremely fast in Hadoop owing to the "move code to data" paradigm.

Hadoop Ecosystem

Following are the components of Hadoop ecosystem:

HDFS: Hadoop Distributed File System. It simply stores data files as close to the original form as possible.

HBase: It is Hadoop's database and compares well with an RDBMS. It supports structured data storage for large tables.

Hive: It enables analysis of large datasets using a language very similar to standard ANSI SQL, which implies that anyone familier with SQL should be able to access data on a Hadoop cluster.

Pig: It is an easy to understand data flow language. It helps with analysis of large datasets which is quite the order with Hadoop. Pig scripts are automatically converted to MapReduce jobs by the Pig interpreter.

ZooKeeper: It is a coordination service for distributed applications.

Oozie: It is a workflow schedular system to manage Apache Hadoop jobs.

Mahout: It is a scalable machine learning and data mining library.

Chukwa: It is data collection system for managing large distributed system.

Sqoop: It is used to transfer bulk data between Hadoop and structured data stores such as relational databases.

Ambari: It is a web based tool for provisioning, managing and monitoring Hadoop clusters.

Hive

Hive is a data warehouse infrastructure tool to process structured data in Hadoop. It resides on top of Hadoop to summarize Big Data and makes querying and analyzing easy.

Hive is not

  1. A relational database

  2. A design for Online Transaction Processing (OLTP).

  3. A language for real-time queries and row-level updates.

Features of Hive

  1. It stores schema in database and processed data into HDFS.

  2. It is designed for OLAP.

  3. It provides SQL type language for querying called HiveQL or HQL.

  4. It is familier, fast, scalable and extensible.

Hive Architecture

The following components are contained in Hive Architecture:

  1. User Interface: Hive is a data warehouse infrastructure that can create interaction between user and HDFS. The User Interfaces that Hive supports are Hive Web UI, Hive Command line and Hive HD Insight(In Windows Server).

  2. MetaStore: Hive chooses respective database servers to store the schema or Metadata of tables, databases, columns in a table, their data types and HDFS mapping.

  3. HiveQL Process Engine: HiveQL is similar to SQL for querying on schema info on the Metastore. It is one of the replacements of traditional approach for MapReduce program. Instead of writing MapReduce in Java, we can write a query for MapReduce and process it.

  4. Exceution Engine: The conjunction part of HiveQL process engine and MapReduce is the Hive Execution Engine. Execution engine processes the query and generates results as same as MapReduce results. It uses the flavor of MapReduce.

  5. HDFS or HBase: Hadoop Distributed File System or HBase are the data storage techniques to store data into file system.

Hive load CSV with commas in quoted fields

keep the delimiter in single quotes it will work.

ROW FORMAT DELIMITED 
FIELDS TERMINATED BY ','
LINES TERMINATED BY '\n';

This will work

How to delete all data from solr and hbase

If you want to clean up Solr index -

you can fire http url -

http://host:port/solr/[core name]/update?stream.body=<delete><query>*:*</query></delete>&commit=true

(replace [core name] with the name of the core you want to delete from). Or use this if posting data xml data:

<delete><query>*:*</query></delete>

Be sure you use commit=true to commit the changes

Don't have much idea with clearing hbase data though.

How to remove hashbang from url?

For Vuejs 2.5 & vue-router 3.0 nothing above worked for me, however after playing around a little bit the following seems to work:

export default new Router({
  mode: 'history',
  hash: false,
  routes: [
  ...
    ,
    { path: '*', redirect: '/' }, // catch all use case
  ],
})

note that you will also need to add the catch-all path.

What is 'PermSize' in Java?

The permament pool contains everything that is not your application data, but rather things required for the VM: typically it contains interned strings, the byte code of defined classes, but also other "not yours" pieces of data.

How to do SELECT MAX in Django?

See this. Your code would be something like the following:

from django.db.models import Max
# Generates a "SELECT MAX..." query
Argument.objects.aggregate(Max('rating')) # {'rating__max': 5}

You can also use this on existing querysets:

from django.db.models import Max
args = Argument.objects.filter(name='foo') # or whatever arbitrary queryset
args.aggregate(Max('rating')) # {'rating__max': 5}

If you need the model instance that contains this max value, then the code you posted is probably the best way to do it:

arg = args.order_by('-rating')[0]

Note that this will error if the queryset is empty, i.e. if no arguments match the query (because the [0] part will raise an IndexError). If you want to avoid that behavior and instead simply return None in that case, use .first():

arg = args.order_by('-rating').first() # may return None

SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column?

I think this should work.

UPDATE QuestionTrackings
SET QuestionID = (SELECT QuestionID
                  FROM AnswerTrackings
                  WHERE AnswerTrackings.AnswerID = QuestionTrackings.AnswerID)
WHERE QuestionID IS NULL
AND AnswerID IS NOT NULL;

How to access /storage/emulated/0/

Also you can use Android Debug Bridge (adb) to copy your file from Android device to folder on your PC:

adb pull /storage/emulated/0/AudioRecorder/1436854479696.mp4 <folder_on_your_PC_e.g. c:/temp>

And you can copy from device whole AudioRecorder folder:

adb pull /storage/emulated/0/AudioRecorder <folder_on_your_PC_e.g. c:/temp>

Remove characters from NSString?

You can try this

- (NSString *)stripRemoveSpaceFrom:(NSString *)str {
    while ([str rangeOfString:@"  "].location != NSNotFound) {
        str = [str stringByReplacingOccurrencesOfString:@" " withString:@""];
    }
    return str;
}

Hope this will help you out.

Using the Jersey client to do a POST operation

Simplest:

Form form = new Form();
form.add("id", "1");    
form.add("name", "supercobra");
ClientResponse response = webResource
  .type(MediaType.APPLICATION_FORM_URLENCODED_TYPE)
  .post(ClientResponse.class, form);

Angular 6: saving data to local storage

First you should understand how localStorage works. you are doing wrong way to set/get values in local storage. Please read this for more information : How to Use Local Storage with JavaScript

How to query the permissions on an Oracle directory?

This should give you the roles, users and permissions granted on a directory:

SELECT * 
  FROM all_tab_privs 
 WHERE table_name = 'your_directory';  --> needs to be upper case

And yes, it IS in the all_TAB_privs view ;-) A better name for that view would be something like "ALL_OBJECT_PRIVS", since it also includes PL/SQL objects and their execute permissions as well.

Android: How to stretch an image to the screen width while maintaining aspect ratio?

Setting adjustViewBounds to true and using a LinearLayout view group worked very well for me. No need to subclass or ask for device metrics:

//NOTE: "this" is a subclass of LinearLayout
ImageView splashImageView = new ImageView(context);
splashImageView.setImageResource(R.drawable.splash);
splashImageView.setAdjustViewBounds(true);
addView(splashImageView);

What is the 'realtime' process priority setting for?

It would be the highest available priority setting, and would usually only be used on box that was dedicated to running that specific program. It's actually high enough that it could cause starvation of the keyboard and mouse threads to the extent that they become unresponsive.

So basicly, if you have to ask, don't use it :)

When to favor ng-if vs. ng-show/ng-hide?

The answer is not simple:

It depends on the target machines (mobile vs desktop), it depends on the nature of your data, the browser, the OS, the hardware it runs on... you will need to benchmark if you really want to know.

It is mostly a memory vs computation problem ... as with most performance issues the difference can become significant with repeated elements (n) like lists, especially when nested (n x n, or worse) and also what kind of computations you run inside these elements:

  • ng-show: If those optional elements are often present (dense), like say 90% of the time, it may be faster to have them ready and only show/hide them, especially if their content is cheap (just plain text, nothing to compute or load). This consumes memory as it fills the DOM with hidden elements, but just show/hide something which already exists is likely to be a cheap operation for the browser.

  • ng-if: If on the contrary elements are likely not to be shown (sparse) just build them and destroy them in real time, especially if their content is expensive to get (computations/sorted/filtered, images, generated images). This is ideal for rare or 'on-demand' elements, it saves memory in terms of not filling the DOM but can cost a lot of computation (creating/destroying elements) and bandwidth (getting remote content). It also depends on how much you compute in the view (filtering/sorting) vs what you already have in the model (pre-sorted/pre-filtered data).

Python convert decimal to hex

I use

"0x%X" % n

where n is the decimal number to convert.

Determine if a String is an Integer in Java

As an alternative approach to trying to parse the string and catching NumberFormatException, you could use a regex; e.g.

if (Pattern.compile("-?[0-9]+").matches(str)) {
    // its an integer
}

This is likely to be faster, especially if you precompile and reuse the regex.

However, the problem with this approach is that Integer.parseInt(str) will also fail if str represents a number that is outside range of legal int values. While it is possible to craft a regex that only matches integers in the range Integer.MIN_INT to Integer.MAX_INT, it is not a pretty sight. (And I am not going to try it ...)

On the other hand ... it may be acceptable to treat "not an integer" and "integer too large" separately for validation purposes.

PHP reindex array?

array_values does the job :

$myArray  = array_values($myArray);

Also some other php function do not preserve the keys, i.e. reset the index.

Add CSS box shadow around the whole DIV

You're offsetting the shadow, so to get it to uniformly surround the box, don't offset it:

-moz-box-shadow: 0 0 3px #ccc;
-webkit-box-shadow: 0 0 3px #ccc;
box-shadow: 0 0 3px #ccc;

How do I tell if a variable has a numeric value in Perl?

Try this:

If (($x !~ /\D/) && ($x ne "")) { ... }

ORA-12505: TNS:listener does not currently know of SID given in connect descriptor (DBD ERROR: OCIServerAttach)

The following worked for me (Windows 7):

oradim -shutdown -sid enter_sid_here
oradim -startup -sid enter_sid_here

(with enter_sid_here replaced by the SID)

Why are my CSS3 media queries not working on mobile devices?

I use a few methods depending. In the same stylesheet i use: @media (max-width: 450px), or for separate make sure you have the link in the header correctly. I had a look at your fixmeup and you have a confusing array of links to css. It acts as you say also on HTC desire S.

Print all day-dates between two dates

Essentially the same as Gringo Suave's answer, but with a generator:

from datetime import datetime, timedelta


def datetime_range(start=None, end=None):
    span = end - start
    for i in xrange(span.days + 1):
        yield start + timedelta(days=i)

Then you can use it as follows:

In: list(datetime_range(start=datetime(2014, 1, 1), end=datetime(2014, 1, 5)))
Out: 
[datetime.datetime(2014, 1, 1, 0, 0),
 datetime.datetime(2014, 1, 2, 0, 0),
 datetime.datetime(2014, 1, 3, 0, 0),
 datetime.datetime(2014, 1, 4, 0, 0),
 datetime.datetime(2014, 1, 5, 0, 0)]

Or like this:

In []: for date in datetime_range(start=datetime(2014, 1, 1), end=datetime(2014, 1, 5)):
   ...:     print date
   ...:     
2014-01-01 00:00:00
2014-01-02 00:00:00
2014-01-03 00:00:00
2014-01-04 00:00:00
2014-01-05 00:00:00

Setting active profile and config location from command line in spring boot

-Dspring.profiles.active=staging -Dspring.config.location=C:\Config

is not correct.

should be:

--spring.profiles.active=staging --spring.config.location=C:\Config

How to check "hasRole" in Java Code with Spring Security?

you can use the isUserInRole method of the HttpServletRequest object.

something like:

public String createForm(HttpSession session, HttpServletRequest request,  ModelMap   modelMap) {


    if (request.isUserInRole("ROLE_ADMIN")) {
        // code here
    }
}

How to make a copy of an object in C#

You can use MemberwiseClone

obj myobj2 = (obj)myobj.MemberwiseClone();

The copy is a shallow copy which means the reference properties in the clone are pointing to the same values as the original object but that shouldn't be an issue in your case as the properties in obj are of value types.

If you own the source code, you can also implement ICloneable

Export specific rows from a PostgreSQL table as INSERT SQL script

For my use-case I was able to simply pipe to grep.

pg_dump -U user_name --data-only --column-inserts -t nyummy.cimory | grep "tokyo" > tokyo.sql

Uninstalling Android ADT

The only way to remove the ADT plugin from Eclipse is to go to Help > About Eclipse/About ADT > Installation Details.

Select a plug-in you want to uninstall, then click Uninstall... button at the bottom.

enter image description here

If you cannot remove ADT from this location, then your best option is probably to start fresh with a clean Eclipse install.

Safely casting long to int in Java

I think I'd do it as simply as:

public static int safeLongToInt(long l) {
    if (l < Integer.MIN_VALUE || l > Integer.MAX_VALUE) {
        throw new IllegalArgumentException
            (l + " cannot be cast to int without changing its value.");
    }
    return (int) l;
}

I think that expresses the intent more clearly than the repeated casting... but it's somewhat subjective.

Note of potential interest - in C# it would just be:

return checked ((int) l);

IOPub data rate exceeded in Jupyter notebook (when viewing image)

By typing 'jupyter notebook --NotebookApp.iopub_data_rate_limit=1.0e10' in Anaconda PowerShell or prompt, the Jupyter notebook will open with the new configuration. Try now to run your query.

Exit from app when click button in android phonegap?

navigator.app.exitApp();

add this line where you want you exit the application.

How to refresh datagrid in WPF

From MSDN -

CollectionViewSource.GetDefaultView(myGrid.ItemsSource).Refresh();

Linq : select value in a datatable column

var name = from DataRow dr in tblClassCode.Rows where (long)dr["ID"] == Convert.ToInt32(i) select (int)dr["Name"]).FirstOrDefault().ToString() 

window.onbeforeunload and window.onunload is not working in Firefox, Safari, Opera?

I got the solution for onunload in all browsers except Opera by changing the Ajax asynchronous request into synchronous request.

xmlhttp.open("POST","LogoutAction",false);

It works well for all browsers except Opera.

Push an associative item into an array in JavaScript

JavaScript doesn't have associate arrays. You need to use Objects instead:

var obj = {};
var name = "name";
var val = 2;
obj[name] = val;
console.log(obj);?

To get value you can use now different ways:

console.log(obj.name);?
console.log(obj[name]);?
console.log(obj["name"]);?

"And" and "Or" troubles within an IF statement

I like assylias' answer, however I would refactor it as follows:

Sub test()

Dim origNum As String
Dim creditOrDebit As String

origNum = "30062600006"
creditOrDebit = "D"

If creditOrDebit = "D" Then
  If origNum = "006260006" Then
    MsgBox "OK"
  ElseIf origNum = "30062600006" Then
    MsgBox "OK"
  End If
End If

End Sub

This might save you some CPU cycles since if creditOrDebit is <> "D" there is no point in checking the value of origNum.

Update:

I used the following procedure to test my theory that my procedure is faster:

Public Declare Function timeGetTime Lib "winmm.dll" () As Long

Sub DoTests2()

  Dim startTime1 As Long
  Dim endTime1 As Long
  Dim startTime2 As Long
  Dim endTime2 As Long
  Dim i As Long
  Dim msg As String

  Const numberOfLoops As Long = 10000
  Const origNum As String = "006260006"
  Const creditOrDebit As String = "D"

  startTime1 = timeGetTime
  For i = 1 To numberOfLoops
    If creditOrDebit = "D" Then
      If origNum = "006260006" Then
        ' do something here
        Debug.Print "OK"
      ElseIf origNum = "30062600006" Then
        ' do something here
        Debug.Print "OK"
      End If
    End If
  Next i
  endTime1 = timeGetTime

  startTime2 = timeGetTime
  For i = 1 To numberOfLoops
    If (origNum = "006260006" Or origNum = "30062600006") And _
      creditOrDebit = "D" Then
      ' do something here
      Debug.Print "OK"
    End If
  Next i
  endTime2 = timeGetTime

  msg = "number of iterations: " & numberOfLoops & vbNewLine
  msg = msg & "JP proc: " & Format$((endTime1 - startTime1), "#,###") & _
       " ms" & vbNewLine
  msg = msg & "assylias proc: " & Format$((endTime2 - startTime2), "#,###") & _
       " ms"

  MsgBox msg

End Sub

I must have a slow computer because 1,000,000 iterations took nowhere near ~200 ms as with assylias' test. I had to limit the iterations to 10,000 -- hey, I have other things to do :)

After running the above procedure 10 times, my procedure is faster only 20% of the time. However, when it is slower it is only superficially slower. As assylias pointed out, however, when creditOrDebit is <>"D", my procedure is at least twice as fast. I was able to reasonably test it at 100 million iterations.

And that is why I refactored it - to short-circuit the logic so that origNum doesn't need to be evaluated when creditOrDebit <> "D".

At this point, the rest depends on the OP's spreadsheet. If creditOrDebit is likely to equal D, then use assylias' procedure, because it will usually run faster. But if creditOrDebit has a wide range of possible values, and D is not any more likely to be the target value, my procedure will leverage that to prevent needlessly evaluating the other variable.

How to check if two arrays are equal with JavaScript?

Check every each value by a for loop once you checked the size of the array.

function equalArray(a, b) {
    if (a.length === b.length) {
        for (var i = 0; i < a.length; i++) {
            if (a[i] !== b[i]) {
                return false;
            }
        }
        return true;
    } else {
        return false;
    }
}

Chrome says my extension's manifest file is missing or unreadable

Some permissions issue for default sample.

I wanted to see how it works, I am creating the first extension, so I downloaded a simpler one.

Downloaded 'Typed URL History' sample from
https://developer.chrome.com/extensions/examples/api/history/showHistory.zip

which can be found at
https://developer.chrome.com/extensions/samples

this worked great, hope it helps

Network tools that simulate slow network connection

You can use dummynet ofcourse, There is extension of dummynet called KauNet. which can provide even more precise control of network conditions. It can drop/delay/re-order specific packets (that way you can perform more in-depth analysis of dropping key packets like TCP handshake to see how your web pages digest it). It also works in time domain. Usually most the emulators are tuned to work in data domain. In time domain you can specify from what time to what time you can alter the network conditions.

Implicit function declarations in C

Because of historical reasons going back to the very first version of C, functions are assumed to have an implicit definition of int function(int arg1, int arg2, int arg3, etc).

Edit: no, I was wrong about int for the arguments. Instead it passes whatever type the argument is. So it could be an int or a double or a char*. Without a prototype the compiler will pass whatever size the argument is and the function being called had better use the correct argument type to receive it.

For more details look up K&R C.

Dealing with nginx 400 "The plain HTTP request was sent to HTTPS port" error

According to wikipedia article on status codes. Nginx has a custom error code when http traffic is sent to https port(error code 497)

And according to nginx docs on error_page, you can define a URI that will be shown for a specific error.
Thus we can create a uri that clients will be sent to when error code 497 is raised.

nginx.conf

#lets assume your IP address is 89.89.89.89 and also 
#that you want nginx to listen on port 7000 and your app is running on port 3000

server {
    listen 7000 ssl;
 
    ssl_certificate /path/to/ssl_certificate.cer;
    ssl_certificate_key /path/to/ssl_certificate_key.key;
    ssl_client_certificate /path/to/ssl_client_certificate.cer;

    error_page 497 301 =307 https://89.89.89.89:7000$request_uri;

    location / {
        proxy_pass http://89.89.89.89:3000/;

        proxy_pass_header Server;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-Protocol $scheme;
    }
}

However if a client makes a request via any other method except a GET, that request will be turned into a GET. Thus to preserve the request method that the client came in via; we use error processing redirects as shown in nginx docs on error_page

And thats why we use the 301 =307 redirect.

Using the nginx.conf file shown here, we are able to have http and https listen in on the same port

How to get number of rows using SqlDataReader in C#

Per above, a dataset or typed dataset might be a good temorary structure which you could use to do your filtering. A SqlDataReader is meant to read the data very quickly. While you are in the while() loop you are still connected to the DB and it is waiting for you to do whatever you are doing in order to read/process the next result before it moves on. In this case you might get better performance if you pull in all of the data, close the connection to the DB and process the results "offline".

People seem to hate datasets, so the above could be done wiht a collection of strongly typed objects as well.

Change R default library path using .libPaths in Rprofile.site fails to work

I was looking into this because R was having issues installing into the default location and was instead just putting the packages into the temp folder. It turned out to be the latest update for Mcaffee Endpoint Security which apparently has issues with R. You can disable the threat protection while you install the packages and it will work properly.

How to post query parameters with Axios?

As of 2021 insted of null i had to add {} in order to make it work!

axios.post(
        url,
        {},
        {
          params: {
            key,
            checksum
          }
        }
      )
      .then(response => {
        return success(response);
      })
      .catch(error => {
        return fail(error);
      });

Message: Trying to access array offset on value of type null

This happens because $cOTLdata is not null but the index 'char_data' does not exist. Previous versions of PHP may have been less strict on such mistakes and silently swallowed the error / notice while 7.4 does not do this anymore.

To check whether the index exists or not you can use isset():

isset($cOTLdata['char_data'])

Which means the line should look something like this:

$len = isset($cOTLdata['char_data']) ? count($cOTLdata['char_data']) : 0;

Note I switched the then and else cases of the ternary operator since === null is essentially what isset already does (but in the positive case).

How to create a POJO?

public class UserInfo {
        String LoginId;
        String Password;
        String FirstName;
        String LastName;
        String Email;
        String Mobile;
        String Address;
        String DOB;

        public String getLoginId() {
            return LoginId;
        }

        public void setLoginId(String loginId) {
            LoginId = loginId;
        }

        public String getPassword() {
            return Password;
        }

        public void setPassword(String password) {
            Password = password;
        }

        public String getFirstName() {
            return FirstName;
        }

        public void setFirstName(String firstName) {
            FirstName = firstName;
        }

        public String getLastName() {
            return LastName;
        }

        public void setLastName(String lastName) {
            LastName = lastName;
        }

        public String getEmail() {
            return Email;
        }

        public void setEmail(String email) {
            Email = email;
        }

        public String getMobile() {
            return Mobile;
        }

        public void setMobile(String mobile) {
            Mobile = mobile;
        }

        public String getAddress() {
            return Address;
        }

        public void setAddress(String address) {
            Address = address;
        }

        public String getDOB() {
            return DOB;
        }

        public void setDOB(String DOB) {
            this.DOB = DOB;
        }
    }

How to rename a table column in Oracle 10g

The syntax of the query is as follows:

Alter table <table name> rename column <column name> to <new column name>;

Example:

Alter table employee rename column eName to empName;

To rename a column name without space to a column name with space:

Alter table employee rename column empName to "Emp Name";

To rename a column with space to a column name without space:

Alter table employee rename column "emp name" to empName;

How can I get a favicon to show up in my django app?

if you have permission then

Alias /favicon.ico /var/www/aktel/workspace1/PyBot/PyBot/static/favicon.ico

add alias to your virtual host. (in apache config file ) similarly for robots.txt

Alias /robots.txt /var/www/---your path ---/PyBot/robots.txt

How do I install jmeter on a Mac?

The easiest way to install it is using Homebrew:

brew install jmeter

Or if you need plugins also:

brew install jmeter --with-plugins

And to open it, use the following command (since it doesn't appear in your Applications):

open /usr/local/bin/jmeter

Difference between binary semaphore and mutex

As many folks here have mentioned, a mutex is used to protect a critical piece of code (AKA critical section.) You will acquire the mutex (lock), enter critical section, and release mutex (unlock) all in the same thread.

While using a semaphore, you can make a thread wait on a semaphore (say thread A), until another thread (say thread B)completes whatever task, and then sets the Semaphore for thread A to stop the wait, and continue its task.

How to list the files in current directory?

Try this,to retrieve all files inside folder and sub-folder

public static void main(String[]args)
    {
        File curDir = new File(".");
        getAllFiles(curDir);
    }
    private static void getAllFiles(File curDir) {

        File[] filesList = curDir.listFiles();
        for(File f : filesList){
            if(f.isDirectory())
                getAllFiles(f);
            if(f.isFile()){
                System.out.println(f.getName());
            }
        }

    }

To retrieve files/folder only

public static void main(String[]args)
    {
        File curDir = new File(".");
        getAllFiles(curDir);
    }
    private static void getAllFiles(File curDir) {

        File[] filesList = curDir.listFiles();
        for(File f : filesList){
            if(f.isDirectory())
                System.out.println(f.getName());
            if(f.isFile()){
                System.out.println(f.getName());
            }
        }

    }

CROSS JOIN vs INNER JOIN in SQL

CROSS JOIN = (INNER) JOIN = comma (",")

TL;DR The only difference between SQL CROSS JOIN, (INNER) JOIN and comma (",") (besides comma having lower precedence for evaluation order) is that (INNER) JOIN has an ON while CROSS JOIN and comma don't.


Re intermediate products

All three produce an intermediate conceptual SQL-style relational "Cartesian" product, aka cross join, of all possible combinations of a row from each table. It is ON and/or WHERE that reduce the number of rows. SQL Fiddle

The SQL Standard defines <comma> via product (7.5 1.b.ii), <cross join> aka CROSS JOIN via <comma> (7.7 1.a) and (INNER) JOIN ON <search condition> via <comma> plus WHERE (7.7 1.b).

As Wikipedia puts it:

Cross join
CROSS JOIN returns the Cartesian product of rows from tables in the join. In other words, it will produce rows which combine each row from the first table with each row from the second table.

Inner join
[...] The result of the join can be defined as the outcome of first taking the Cartesian product (or Cross join) of all records in the tables (combining every record in table A with every record in table B) and then returning all records which satisfy the join predicate.

The "implicit join notation" simply lists the tables for joining, in the FROM clause of the SELECT statement, using commas to separate them. Thus it specifies a cross join

Re OUTER JOIN see my answer What is the difference between “INNER JOIN” and “OUTER JOIN”?.

Re OUTER JOINs and using ON vs WHERE in them see my answer Conditions in LEFT JOIN (OUTER JOIN) vs INNER JOIN.

Why compare columns between tables?

When there are no duplicate rows:

Every table holds the rows that make a true statement from a certain fill-in-the-[named-]blanks statement template. (It makes a true proposition from--satisfies--a certain (characteristic) predicate.)

  • A base table holds the rows that make a true statement from some DBA-given statement template:

      /* rows where
      customer C.CustomerID has age C.Age and ...
      */
      FROM Customers C
    
  • A join's intermediate product holds the rows that make a true statement from the AND of its operands' templates:

      /* rows where
          customer C.CustomerID has age C.Age and ...
      AND movie M.Movie is rented by customer M.CustomerID and ...
      */
      FROM Customers C CROSS JOIN Movies M
    
  • ON & WHERE conditions are ANDed in to give a further template. The value is again the rows that satisfy that template:

      /* rows where
          customer C.CustomerID has age C.Age and ...
      AND movie M.Movie is rented by customer M.CustomerID and ...
      AND C.CustomerID = M.CustomerID
      AND C.Age >= M.[Minimum Age]
      AND C.Age = 18
      */
      FROM Customers C INNER JOIN Movies M
      ON C.CustomerID = M.CustomerID
      AND C.Age >= M.[Minimum Age]
      WHERE C.Age = 18
    

In particular, comparing columns for (SQL) equality between tables means that the rows kept from the product from the joined tables' parts of the template have the same (non-NULL) value for those columns. It's just coincidental that a lot of rows are typically removed by equality comparisons between tables--what is necessary and sufficient is to characterize the rows you want.

Just write SQL for the template for the rows you want!

Re the meaning of queries (and tables vs conditions) see:
How to get matching data from another SQL table for two different columns: Inner Join and/or Union?
Is there any rule of thumb to construct SQL query from a human-readable description?

Overloading "cross join"

Unfortunately the term "cross join" gets used for:

  • The intermediate product.
  • CROSS JOIN.
  • (INNER) JOIN with an ON or WHERE that doesn't compare any columns from one table to any columns of another. (Since that tends to return so many of the intermediate product rows.)

These various meanings get confounded. (Eg as in other answers and comments here.)

Using CROSS JOIN vs (INNER) JOIN vs comma

The common convention is:

  • Use CROSS JOIN when and only when you don't compare columns between tables. That is to show that the lack of comparisons was intentional.
  • Use (INNER) JOIN with ON when and only when you compare columns between tables. (Plus possibly other conditions.)
  • Don't use comma.

Typically also conditions not on pairs of tables are kept for a WHERE. But they may have to be put in a(n INNER) JOIN ON to get appropriate rows for the argument to a RIGHT, LEFT or FULL (OUTER) JOIN.

Re "Don't use comma" Mixing comma with explicit JOIN can mislead because comma has lower precedence. But given the role of the intermediate product in the meaning of CROSS JOIN, (INNER) JOIN and comma, arguments for the convention above of not using it at all are shaky. A CROSS JOIN or comma is just like an (INNER) JOIN that's ON a TRUE condition. An intermediate product, ON and WHERE all introduce an AND in the corresponding predicate. However else INNER JOIN ON can be thought of--say, generating an output row only when finding a pair of input rows that satisfies the ON condition--it nevertheless returns the cross join rows that satisfy the condition. The only reason ON had to supplement comma in SQL was to write OUTER JOINs. Of course, an expression should make its meaning clear; but what is clear depends on what things are taken to mean.

Re Venn diagrams A Venn diagram with two intersecting circles can illustrate the difference between output rows for INNER, LEFT, RIGHT & FULL JOINs for the same input. And when the ON is unconditionally TRUE, the INNER JOIN result is the same as CROSS JOIN. Also it can illustrate the input and output rows for INTERSECT, UNION & EXCEPT. And when both inputs have the same columns, the INTERSECT result is the same as for standard SQL NATURAL JOIN, and the EXCEPT result is the same as for certain idioms involving LEFT & RIGHT JOIN. But it does not illustrate how (INNER) JOIN works in general. That just seems plausible at first glance. It can identify parts of input and/or output for special cases of ON, PKs (primary keys), FKs (foreign keys) and/or SELECT. All you have to do to see this is to identify what exactly are the elements of the sets represented by the circles. (Which muddled presentations never make clear.) Remember that in general for joins output rows have different headings from input rows. And SQL tables are bags not sets of rows with NULLs.

copy all files and folders from one drive to another drive using DOS (command prompt)

xcopy "C:\SomeFolderName" "D:\SomeFolderName" /h /i /c /k /e /r /y

Use the above command. It will definitely work.

In this command data will be copied from c:\ to D:\, even folders and system files as well. Here's what the flags do:

  • /h copies hidden and system files also
  • /i if destination does not exist and copying more than one file, assume that destination must be a directory
  • /c continue copying even if error occurs
  • /k copies attributes
  • /e copies directories and subdirectories, including empty ones
  • /r overwrites read-only files
  • /y suppress prompting to confirm whether you want to overwrite a file

Get folder up one level

You could do either:

dirname(__DIR__);

Or:

__DIR__ . '/..';

...but in a web server environment you will probably find that you are already working from current file's working directory, so you can probably just use:

'../'

...to reference the directory above. You can replace __DIR__ with dirname(__FILE__) before PHP 5.3.0.

You should also be aware what __DIR__ and __FILE__ refers to:

The full path and filename of the file. If used inside an include, the name of the included file is returned.

So it may not always point to where you want it to.

Android getResources().getDrawable() deprecated API 22

You have some options to handle this deprecation the right (and future proof) way, depending on which kind of drawable you are loading:


A) drawables with theme attributes

ContextCompat.getDrawable(getActivity(), R.drawable.name);

You'll obtain a styled Drawable as your Activity theme instructs. This is probably what you need.


B) drawables without theme attributes

ResourcesCompat.getDrawable(getResources(), R.drawable.name, null);

You'll get your unstyled drawable the old way. Please note: ResourcesCompat.getDrawable() is not deprecated!


EXTRA) drawables with theme attributes from another theme

ResourcesCompat.getDrawable(getResources(), R.drawable.name, anotherTheme);

Scripting Language vs Programming Language

The differences are becoming fewer and less important. Traditionally, scripting languages extend existing programs... I think that's the main definition of "scripting" is that it refers to writing a set of instructions for an existing entity to perform. However, where scripting languages started with proprietary and colloquial syntax, most of the prevalent ones these days owe some relationship to C.

I think the "interpreted vs compiled" distinction is really a symptom of extending an existing program (with a built in interpreter), rather than an intrinsic difference. What programmers and laymen are more concerned about is, "what is the programmer doing?" The fact that one program is interpreted and another is compiled means very little in determining the difference in activity by the creator. You don't judge a playwright on whether his plays are more commonly read aloud or performed on stage, do you?

How to install the Sun Java JDK on Ubuntu 10.10 (Maverick Meerkat)?

Update (2010/10/01): Yesss, Sun Java Finally Uploaded To The Ubuntu 10.10 Maverick Official Partner Repository.


Update (2010/09/27): Readers might want to check Sun Java6 Packages [updated]. I still expect official packages to be available in the partner repos at releast time though.


For an unknown reason, the sun-java6-jdk are not yet available in the partner repositories.

So either downloaded the required packages from http://archive.canonical.com/pool/partner/s/sun-java6/ and install them with dpkg -i.

Or temporarily replace the maverick partner repository

http://archive.canonical.com/ubuntu maverick partner

by the lucid one (replace maverick by lucid in the above line, let me know if you need more help to do this). Then, install sun-java6. And revert the change.

onKeyPress Vs. onKeyUp and onKeyDown

A few practical facts that might be useful to decide which event to handle (run the script below and focus on the input box):

_x000D_
_x000D_
$('input').on('keyup keydown keypress',e=>console.log(e.type, e.keyCode, e.which, e.key))
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<input/>
_x000D_
_x000D_
_x000D_

Pressing:

  • non inserting/typing keys (e.g. Shift, Ctrl) will not trigger a keypress. Press Ctrl and release it:

    keydown 17 17 Control

    keyup 17 17 Control

  • keys from keyboards that apply characters transformations to other characters may lead to Dead and duplicate "keys" (e.g. ~, ´) on keydown. Press ´ and release it in order to display a double ´´:

    keydown 192 192 Dead

    keydown 192 192 ´´

    keypress 180 180 ´

    keypress 180 180 ´

    keyup 192 192 Dead

Additionally, non typing inputs (e.g. ranged <input type="range">) will still trigger all keyup, keydown and keypress events according to the pressed keys.

ORA-00904: invalid identifier

I had this error when trying to save an entity through JPA.

It was because I had a column with @JoinColumn annotation that didn't have @ManyToOne annotation.

Adding @ManyToOne fixed the issue.

How to check if "Radiobutton" is checked?

If you need for espresso test the solutions is like this :

onView(withId(id)).check(matches(isChecked()));

Bye,

Display curl output in readable JSON format in Unix shell script

With :

curl <...> | xidel - -se '$json'

xidel can probably retrieve the JSON for you as well.

"Cannot send session cache limiter - headers already sent"

"Headers already sent" means that your PHP script already sent the HTTP headers, and as such it can't make modifications to them now.

Check that you don't send ANY content before calling session_start. Better yet, just make session_start the first thing you do in your PHP file (so put it at the absolute beginning, before all HTML etc).

Drop data frame columns by name

Provide the data frame and a string of comma separated names to remove:

remove_features <- function(df, features) {
  rem_vec <- unlist(strsplit(features, ', '))
  res <- df[,!(names(df) %in% rem_vec)]
  return(res)
}

Usage:

remove_features(iris, "Sepal.Length, Petal.Width")

enter image description here

ModelState.AddModelError - How can I add an error that isn't for a property?

I eventually stumbled upon an example of the usage I was looking for - to assign an error to the Model in general, rather than one of it's properties, as usual you call:

ModelState.AddModelError(string key, string errorMessage);

but use an empty string for the key:

ModelState.AddModelError(string.Empty, "There is something wrong with Foo.");

The error message will present itself in the <%: Html.ValidationSummary() %> as you'd expect.

How do you send a Firebase Notification to all devices via CURL?

I was looking solution for my Ionic Cordova app push notification.

Thanks to Syed Rafay's answer.

in app.component.ts

const options: PushOptions = {
  android: {
    topics: ['all']
  },

in Server file

"to" => "/topics/all",

How do I sort arrays using vbscript?

If you are going to output the lines anyway, you could run the output through the sort command. Not elegant, but it does not require much work:

cscript.exe //nologo YOUR-SCRIPT | Sort

Note //nologo omits the logo lines (Microsoft (R) Windows Script Host Version... blah blah blah) from appearing in the middle of your sorted output. (I guess MS does not know what stderr is for.)

See http://ss64.com/nt/sort.html for details on sort.

/+n is the most useful option if your sort key does not start in the first column.

Compares are always case-insensitive, which is lame.

How to find serial number of Android device?

I found the example class posted by @emmby above to be a great starting point. But it has a couple of flaws, as mentioned by other posters. The major one is that it persists the UUID to an XML file unnecessarily and thereafter always retrieves it from this file. This lays the class open to an easy hack: anyone with a rooted phone can edit the XML file to give themselves a new UUID.

I've updated the code so that it only persists to XML if absolutely necessary (i.e. when using a randomly generated UUID) and re-factored the logic as per @Brill Pappin's answer:

import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings.Secure;
import android.telephony.TelephonyManager;

import java.io.UnsupportedEncodingException;
import java.util.UUID;

public class DeviceUuidFactory {
    protected static final String PREFS_FILE = "device_id.xml";
    protected static final String PREFS_DEVICE_ID = "device_id";

    protected static UUID uuid;

    public DeviceUuidFactory(Context context) {

        if( uuid ==null ) {
            synchronized (DeviceUuidFactory.class) {
                if( uuid == null) {
                    final SharedPreferences prefs = context.getSharedPreferences( PREFS_FILE, 0);
                    final String id = prefs.getString(PREFS_DEVICE_ID, null );

                    if (id != null) {
                        // Use the ids previously computed and stored in the prefs file
                        uuid = UUID.fromString(id);

                    } else {

                        final String androidId = Secure.getString(context.getContentResolver(), Secure.ANDROID_ID);

                        // Use the Android ID unless it's broken, in which case fallback on deviceId,
                        // unless it's not available, then fallback on a random number which we store
                        // to a prefs file
                        try {
                             if ( "9774d56d682e549c".equals(androidId) || (androidId == null) ) {
                                final String deviceId = ((TelephonyManager) context.getSystemService( Context.TELEPHONY_SERVICE )).getDeviceId();

                                if (deviceId != null)
                                {
                                    uuid = UUID.nameUUIDFromBytes(deviceId.getBytes("utf8"));
                                }
                                else
                                {
                                    uuid = UUID.randomUUID();

                                    // Write the value out to the prefs file so it persists
                                    prefs.edit().putString(PREFS_DEVICE_ID, uuid.toString() ).commit();
                                }
                            }
                            else
                            {
                                uuid = UUID.nameUUIDFromBytes(androidId.getBytes("utf8"));
                            } 
                        } catch (UnsupportedEncodingException e) {
                            throw new RuntimeException(e);
                        }



                    }

                }
            }
        }

    }


    /**
     * Returns a unique UUID for the current android device.  As with all UUIDs, this unique ID is "very highly likely"
     * to be unique across all Android devices.  Much more so than ANDROID_ID is.
     *
     * The UUID is generated by using ANDROID_ID as the base key if appropriate, falling back on
     * TelephonyManager.getDeviceID() if ANDROID_ID is known to be incorrect, and finally falling back
     * on a random UUID that's persisted to SharedPreferences if getDeviceID() does not return a
     * usable value.
     *
     * In some rare circumstances, this ID may change.  In particular, if the device is factory reset a new device ID
     * may be generated.  In addition, if a user upgrades their phone from certain buggy implementations of Android 2.2
     * to a newer, non-buggy version of Android, the device ID may change.  Or, if a user uninstalls your app on
     * a device that has neither a proper Android ID nor a Device ID, this ID may change on reinstallation.
     *
     * Note that if the code falls back on using TelephonyManager.getDeviceId(), the resulting ID will NOT
     * change after a factory reset.  Something to be aware of.
     *
     * Works around a bug in Android 2.2 for many devices when using ANDROID_ID directly.
     *
     * @see http://code.google.com/p/android/issues/detail?id=10603
     *
     * @return a UUID that may be used to uniquely identify your device for most purposes.
     */
    public UUID getDeviceUuid() {
        return uuid;
    }

How can change width of dropdown list?

try the !important argument to make sure the CSS is not conflicting with any other styles you have specified. Also using a reset.css is good before you add your own styles.

select#wgmstr {
    max-width: 50px;
    min-width: 50px;
    width: 50px !important;
}

or

<select name="wgtmsr" id="wgtmsr" style="width: 50px !important; min-width: 50px; max-width: 50px;">

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

on a Mac you might see the image:

enter image description here

if you right click on the docker icon then you see:

enter image description here

alternatively:

docker ps

and

docker run hello-world

postgresql port confusion 5433 or 5432?

For me in PgAdmin 4 on Mac OS High Sierra, Clicking the PostrgreSQL10 database under Servers in the left column, then the Properties tab, showed 5433 as the port under Connection. (I don't know why, because I chose 5432 during install). Anyway, I clicked the Edit icon under the Properties tab, change that to 5432, saved, and that solved the problem. Go figure.

How to get a list of all files that changed between two Git commits?

  • To list all unstaged tracked changed files:

    git diff --name-only
    
  • To list all staged tracked changed files:

    git diff --name-only --staged
    
  • To list all staged and unstaged tracked changed files:

    { git diff --name-only ; git diff --name-only --staged ; } | sort | uniq
    
  • To list all untracked files (the ones listed by git status, so not including any ignored files):

    git ls-files --other --exclude-standard
    

If you're using this in a shell script, and you want to programmatically check if these commands returned anything, you'll be interested in git diff's --exit-code option.

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/core"

This is a very common error while working on JSTL.

To solve this error simply :-

  1. Download jstl-1.1.2.jar and standard-1.1.2.jar
  2. And then just paste them in lib folder under WEB-INF of your Dynamic Web App project.

You will find the error has gone now!

Hope this helps.

In Java, how to append a string more efficiently?

java.lang.StringBuilder. Use int constructor to create an initial size.

jQuery if Element has an ID?

You can do this:

if ($(".parent a[Id]").length > 0) {

    /* then do something here */

}

How can you program if you're blind?

Keep in mind that "blind" is a range of conditions - there are some who are legally blind that could read a really large monitor or with magnification help, and then there are those who have no vision at all. I remember a classmate in college who had a special device to magnify books, and special software she could use to magnify a part of the screen. She was working hard to finish college, because her eyesight was getting worse and was going to go away completely.

Programming also has a spectrum of needs - some people are good at cranking out lots and lots of code, and some people are better at looking at the big picture and architecture. I would imagine that given the difficulty imposed by the screen interface, blindness may enhance your ability to get the big picture...

Compiling and Running Java Code in Sublime Text 2

This is code to compile and run java in sublime text 3

"shell_cmd": "javac -d . $file && java ${file_base_name}.${file_base_name}", "shell": true

Processing $http response in service

Please try the below Code

You can split the controller (PageCtrl) and service (dataService)

_x000D_
_x000D_
'use strict';_x000D_
(function () {_x000D_
    angular.module('myApp')_x000D_
        .controller('pageContl', ['$scope', 'dataService', PageContl])_x000D_
        .service('dataService', ['$q', '$http', DataService]);_x000D_
    function DataService($q, $http){_x000D_
        this.$q = $q;_x000D_
        this.$http = $http;_x000D_
        //... blob blob _x000D_
    }_x000D_
    DataService.prototype = {_x000D_
        getSearchData: function () {_x000D_
            var deferred = this.$q.defer(); //initiating promise_x000D_
            this.$http({_x000D_
                method: 'POST',//GET_x000D_
                url: 'test.json',_x000D_
                headers: { 'Content-Type': 'application/json' }_x000D_
            }).then(function(result) {_x000D_
                deferred.resolve(result.data);_x000D_
            },function (error) {_x000D_
                deferred.reject(error);_x000D_
            });_x000D_
            return deferred.promise;_x000D_
        },_x000D_
        getABCDATA: function () {_x000D_
_x000D_
        }_x000D_
    };_x000D_
    function PageContl($scope, dataService) {_x000D_
        this.$scope = $scope;_x000D_
        this.dataService = dataService; //injecting service Dependency in ctrl_x000D_
        this.pageData = {}; //or [];_x000D_
    }_x000D_
    PageContl.prototype = {_x000D_
         searchData: function () {_x000D_
             var self = this; //we can't access 'this' of parent fn from callback or inner function, that's why assigning in temp variable_x000D_
             this.dataService.getSearchData().then(function (data) {_x000D_
                 self.searchData = data;_x000D_
             });_x000D_
         }_x000D_
    }_x000D_
}());
_x000D_
_x000D_
_x000D_

Android Firebase, simply get one child object's data

just fetch specific node data and its working perfect for me

mFirebaseInstance.getReference("yourNodeName").getRef().addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {


        for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
            Log.e(TAG, "======="+postSnapshot.child("email").getValue());
            Log.e(TAG, "======="+postSnapshot.child("name").getValue());
        }
    }

    @Override
    public void onCancelled(DatabaseError error) {
        // Failed to read value
        Log.e(TAG, "Failed to read app title value.", error.toException());
    }
});

Confusing error in R: Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, : line 1 did not have 42 elements)

read.table wants to return a data.frame, which must have an element in each column. Therefore R expects each row to have the same number of elements and it doesn't fill in empty spaces by default. Try read.table("/PathTo/file.csv" , fill = TRUE ) to fill in the blanks.

e.g.

read.table( text= "Element1 Element2
Element5 Element6 Element7" , fill = TRUE , header = FALSE )
#        V1       V2       V3
#1 Element1 Element2         
#2 Element5 Element6 Element7

A note on whether or not to set header = FALSE... read.table tries to automatically determine if you have a header row thus:

header is set to TRUE if and only if the first row contains one fewer field than the number of columns

Groovy: How to check if a string contains any element of an array?

def valid = pointAddress.findAll { a ->
    validPointTypes.any { a.contains(it) }
}

Should do it

ImportError: libSM.so.6: cannot open shared object file: No such file or directory

You need to add sudo . I did the following to get it installed :

sudo apt-get install libsm6 libxrender1 libfontconfig1

and then did that (optional! maybe you won't need it)

sudo python3 -m pip install opencv-contrib-python

FINALLY got it done !

Fragment pressing back button

Still better solution could be to follow a design pattern such that the back-button press event gets propagated from active fragment down to host Activity. So, it's like.. if one of the active fragments consume the back-press, the Activity wouldn't get to act upon it, and vice-versa.

One way to do it is to have all your Fragments extend a base fragment that has an abstract 'boolean onBackPressed()' method.

@Override
public boolean onBackPressed() {
   if(some_condition)
      // Do something
      return true; //Back press consumed.
   } else {
      // Back-press not consumed. Let Activity handle it
      return false;
   }
}

Keep track of active fragment inside your Activity and inside it's onBackPressed callback write something like this

@Override
public void onBackPressed() {
   if(!activeFragment.onBackPressed())
      super.onBackPressed();
   }
}

This post has this pattern described in detail

React Native TextInput that only accepts numeric characters

This not work on IOS, setState -> render -> not change the text, but can change other. The textinput can't change itself value when textOnChange.

by the way, This work well on Android.

Java Date vs Calendar

Date is a simpler class and is mainly there for backward compatibility reasons. If you need to set particular dates or do date arithmetic, use a Calendar. Calendars also handle localization. The previous date manipulation functions of Date have since been deprecated.

Personally I tend to use either time in milliseconds as a long (or Long, as appropriate) or Calendar when there is a choice.

Both Date and Calendar are mutable, which tends to present issues when using either in an API.

R - Concatenate two dataframes?

You may use rbind but in this case you need to have the same number of columns in both tables, so try the following:

b$b<-as.double(NA) #keeping numeric format is essential for further calculations
new<-rbind(a,b)

How can I check if an InputStream is empty without reading from it?

If the InputStream you're using supports mark/reset support, you could also attempt to read the first byte of the stream and then reset it to its original position:

input.mark(1);
final int bytesRead = input.read(new byte[1]);
input.reset();
if (bytesRead != -1) {
    //stream not empty
} else {
    //stream empty
} 

If you don't control what kind of InputStream you're using, you can use the markSupported() method to check whether mark/reset will work on the stream, and fall back to the available() method or the java.io.PushbackInputStream method otherwise.

Fullscreen Activity in Android?

With kotlin this is the way I did:

class LoginActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)
        window.decorView.systemUiVisibility =
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE or
                View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN or
                View.SYSTEM_UI_FLAG_FULLSCREEN

    }
}

Immersive Mode

The immersive mode is intended for apps in which the user will be heavily interacting with the screen. Examples are games, viewing images in a gallery, or reading paginated content, like a book or slides in a presentation. For this, just add this lines:

View.SYSTEM_UI_FLAG_HIDE_NAVIGATION or
View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION

Sticky immersive

In the regular immersive mode, any time a user swipes from an edge, the system takes care of revealing the system bars—your app won't even be aware that the gesture occurred. So if the user might actually need to swipe from the edge of the screen as part of the primary app experience—such as when playing a game that requires lots of swiping or using a drawing app—you should instead enable the "sticky" immersive mode.

View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY

For more information: Enable fullscreen mode

In case your using the keyboard, sometimes happens that StatusBar shows when keyboard shows up. In that case I usually add this to my style xml

styles.xml

<style name="FullScreen" parent="AppTheme">
    <item name="android:windowFullscreen">true</item>
</style>

And also this line to my manifest

<activity
        android:name=".ui.login.LoginActivity"
        android:label="@string/title_activity_login"
        android:theme="@style/FullScreen">

jQuery Cross Domain Ajax

Here is the snippets from my code.. If it solves your problems..

Client Code :

Set jsonpCallBack : 'photos' and dataType:'jsonp'

 $('document').ready(function() {
            var pm_url = 'http://localhost:8080/diztal/rest/login/test_cor?sessionKey=4324234';
            $.ajax({
                crossDomain: true,
                url: pm_url,
                type: 'GET',
                dataType: 'jsonp',
                jsonpCallback: 'photos'
            });
        });
        function photos (data) {
            alert(data);
            $("#twitter_followers").html(data.responseCode);
        };

Server Side Code (Using Rest Easy)

@Path("/test_cor")
@GET
@Produces(MediaType.TEXT_PLAIN)
public String testCOR(@QueryParam("sessionKey") String sessionKey, @Context HttpServletRequest httpRequest) {
    ResponseJSON<LoginResponse> resp = new ResponseJSON<LoginResponse>();
    resp.setResponseCode(sessionKey);
    resp.setResponseText("Wrong Passcode");
    resp.setResponseTypeClass("Login");
    Gson gson = new Gson();
    return "photos("+gson.toJson(resp)+")"; // CHECK_THIS_LINE
}

How can I overwrite file contents with new content in PHP?

Use file_put_contents()

file_put_contents('file.txt', 'bar');
echo file_get_contents('file.txt'); // bar
file_put_contents('file.txt', 'foo');
echo file_get_contents('file.txt'); // foo

Alternatively, if you're stuck with fopen() you can use the w or w+ modes:

'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

'w+' Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

How do I open workbook programmatically as read-only?

Does this work?

Workbooks.Open Filename:=filepath, ReadOnly:=True

Or, as pointed out in a comment, to keep a reference to the opened workbook:

Dim book As Workbook
Set book = Workbooks.Open(Filename:=filepath, ReadOnly:=True)

NotificationCenter issue on Swift 3

For all struggling around with the #selector in Swift 3 or Swift 4, here a full code example:

// WE NEED A CLASS THAT SHOULD RECEIVE NOTIFICATIONS
    class MyReceivingClass {

    // ---------------------------------------------
    // INIT -> GOOD PLACE FOR REGISTERING
    // ---------------------------------------------
    init() {
        // WE REGISTER FOR SYSTEM NOTIFICATION (APP WILL RESIGN ACTIVE)

        // Register without parameter
        NotificationCenter.default.addObserver(self, selector: #selector(MyReceivingClass.handleNotification), name: .UIApplicationWillResignActive, object: nil)

        // Register WITH parameter
        NotificationCenter.default.addObserver(self, selector: #selector(MyReceivingClass.handle(withNotification:)), name: .UIApplicationWillResignActive, object: nil)
    }

    // ---------------------------------------------
    // DE-INIT -> LAST OPTION FOR RE-REGISTERING
    // ---------------------------------------------
    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    // either "MyReceivingClass" must be a subclass of NSObject OR selector-methods MUST BE signed with '@objc'

    // ---------------------------------------------
    // HANDLE NOTIFICATION WITHOUT PARAMETER
    // ---------------------------------------------
    @objc func handleNotification() {
        print("RECEIVED ANY NOTIFICATION")
    }

    // ---------------------------------------------
    // HANDLE NOTIFICATION WITH PARAMETER
    // ---------------------------------------------
    @objc func handle(withNotification notification : NSNotification) {
        print("RECEIVED SPECIFIC NOTIFICATION: \(notification)")
    }
}

In this example we try to get POSTs from AppDelegate (so in AppDelegate implement this):

// ---------------------------------------------
// WHEN APP IS GOING TO BE INACTIVE
// ---------------------------------------------
func applicationWillResignActive(_ application: UIApplication) {

    print("POSTING")

    // Define identifiyer
    let notificationName = Notification.Name.UIApplicationWillResignActive

    // Post notification
    NotificationCenter.default.post(name: notificationName, object: nil)
}

React - changing an uncontrolled input

One potential downside with setting the field value to "" (empty string) in the constructor is if the field is an optional field and is left unedited. Unless you do some massaging before posting your form, the field will be persisted to your data storage as an empty string instead of NULL.

This alternative will avoid empty strings:

constructor(props) {
    super(props);
    this.state = {
        name: null
    }
}

... 

<input name="name" type="text" value={this.state.name || ''}/>

Python import csv to list

Next is a piece of code which uses csv module but extracts file.csv contents to a list of dicts using the first line which is a header of csv table

import csv
def csv2dicts(filename):
  with open(filename, 'rb') as f:
    reader = csv.reader(f)
    lines = list(reader)
    if len(lines) < 2: return None
    names = lines[0]
    if len(names) < 1: return None
    dicts = []
    for values in lines[1:]:
      if len(values) != len(names): return None
      d = {}
      for i,_ in enumerate(names):
        d[names[i]] = values[i]
      dicts.append(d)
    return dicts
  return None

if __name__ == '__main__':
  your_list = csv2dicts('file.csv')
  print your_list

Difference between multitasking, multithreading and multiprocessing?

A multiprogramming is the process when a computer system is performing different tasks all at once in a single computer system.

Export to CSV using jQuery and html

A tiny update for @Terry Young answer, i.e. add IE 10+ support

if (window.navigator.msSaveOrOpenBlob) {
  // IE 10+
  var blob = new Blob([decodeURIComponent(encodeURI(csvString))], {
    type: 'text/csv;charset=' + document.characterSet
  });
  window.navigator.msSaveBlob(blob, filename);
} else {
  // actual real browsers
  //Data URI
  csvData = 'data:application/csv;charset=utf-8,' + encodeURIComponent(csvData);

    $(this).attr({
      'download': filename,
      'href': csvData,
      'target': '_blank'
    });
}

Using an integer as a key in an associative array in JavaScript

Sometimes I use a prefixes for my keys. For example:

var pre = 'foo',
    key = pre + 1234

obj = {};

obj[key] = val;

Now you don't have any problem accessing them.

Smooth scroll to div id jQuery

Here is my solution to smooth scroll to div / anchor using jQuery in case you have a fixed header so that it doesn't scroll underneath it. Also it works if you link it from other page.

Just replace ".site-header" to div that contains your header.

$(function() {

$('a[href*="#"]:not([href="#"])').click(function() {
var headerheight = $(".site-header").outerHeight();
if (location.pathname.replace(/^\//,'') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname) {
  var target = $(this.hash);
  target = target.length ? target : $('[name=' + this.hash.slice(1) +']');

  if (target.length) {
    $('html, body').animate({
      scrollTop: (target.offset().top - headerheight)
    }, 1000);
    return false;
  }
}
});

//Executed on page load with URL containing an anchor tag.
if($(location.href.split("#")[1])) {
var headerheight = $(".site-header").outerHeight();
  var target = $('#'+location.href.split("#")[1]);
  if (target.length) {
    $('html,body').animate({
      scrollTop: target.offset().top - headerheight
    }, 1);
    return false;
  }
}
});

How can I tell gcc not to inline a function?

You want the gcc-specific noinline attribute.

This function attribute prevents a function from being considered for inlining. If the function does not have side-effects, there are optimizations other than inlining that causes function calls to be optimized away, although the function call is live. To keep such calls from being optimized away, put asm ("");

Use it like this:

void __attribute__ ((noinline)) foo() 
{
  ...
}

What does the "assert" keyword do?

It ensures that the expression returns true. Otherwise, it throws a java.lang.AssertionError.

http://java.sun.com/docs/books/jls/third_edition/html/statements.html#14.10

Deep copy of a dict in python

I like and learned a lot from Lasse V. Karlsen. I modified it into the following example, which highlights pretty well the difference between shallow dictionary copies and deep copies:

    import copy

    my_dict = {'a': [1, 2, 3], 'b': [4, 5, 6]}
    my_copy = copy.copy(my_dict)
    my_deepcopy = copy.deepcopy(my_dict)

Now if you change

    my_dict['a'][2] = 7

and do

    print("my_copy a[2]: ",my_copy['a'][2],",whereas my_deepcopy a[2]: ", my_deepcopy['a'][2])

you get

    >> my_copy a[2]:  7 ,whereas my_deepcopy a[2]:  3

How to build an APK file in Eclipse?

No one mentioned this, but in conjunction to the other responses, you can also get the apk file from your bin directory to your phone or tablet by putting it on a web site and just downloading it.

Your device will complain about installing it after you download it. Your device will advise you or a risk of installing programs from unknown sources and give you the option to bypass the advice.

Your question is very specific. You don't have to pull it from your emulator, just grab the apk file from the bin folder in your project and place it on your real device.

Most people are giving you valuable information for the next step (signing and publishing your apk), you are not required to do that step to get it on your real device.

Downloading it to your real device is a simple method.

multiprocessing.Pool: When to use apply, apply_async or map?

Back in the old days of Python, to call a function with arbitrary arguments, you would use apply:

apply(f,args,kwargs)

apply still exists in Python2.7 though not in Python3, and is generally not used anymore. Nowadays,

f(*args,**kwargs)

is preferred. The multiprocessing.Pool modules tries to provide a similar interface.

Pool.apply is like Python apply, except that the function call is performed in a separate process. Pool.apply blocks until the function is completed.

Pool.apply_async is also like Python's built-in apply, except that the call returns immediately instead of waiting for the result. An AsyncResult object is returned. You call its get() method to retrieve the result of the function call. The get() method blocks until the function is completed. Thus, pool.apply(func, args, kwargs) is equivalent to pool.apply_async(func, args, kwargs).get().

In contrast to Pool.apply, the Pool.apply_async method also has a callback which, if supplied, is called when the function is complete. This can be used instead of calling get().

For example:

import multiprocessing as mp
import time

def foo_pool(x):
    time.sleep(2)
    return x*x

result_list = []
def log_result(result):
    # This is called whenever foo_pool(i) returns a result.
    # result_list is modified only by the main process, not the pool workers.
    result_list.append(result)

def apply_async_with_callback():
    pool = mp.Pool()
    for i in range(10):
        pool.apply_async(foo_pool, args = (i, ), callback = log_result)
    pool.close()
    pool.join()
    print(result_list)

if __name__ == '__main__':
    apply_async_with_callback()

may yield a result such as

[1, 0, 4, 9, 25, 16, 49, 36, 81, 64]

Notice, unlike pool.map, the order of the results may not correspond to the order in which the pool.apply_async calls were made.


So, if you need to run a function in a separate process, but want the current process to block until that function returns, use Pool.apply. Like Pool.apply, Pool.map blocks until the complete result is returned.

If you want the Pool of worker processes to perform many function calls asynchronously, use Pool.apply_async. The order of the results is not guaranteed to be the same as the order of the calls to Pool.apply_async.

Notice also that you could call a number of different functions with Pool.apply_async (not all calls need to use the same function).

In contrast, Pool.map applies the same function to many arguments. However, unlike Pool.apply_async, the results are returned in an order corresponding to the order of the arguments.

How to get HTTP response code for a URL in Java?

HttpURLConnection:

URL url = new URL("http://example.com");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("GET");
connection.connect();

int code = connection.getResponseCode();

This is by no means a robust example; you'll need to handle IOExceptions and whatnot. But it should get you started.

If you need something with more capability, check out HttpClient.

Dump a mysql database to a plaintext (CSV) backup from the command line

If you really need a "Backup" then you also need database schema, like table definitions, view definitions, store procedures and so on. A backup of a database isn't just the data.

The value of the mysqldump format for backup is specifically that it is very EASY to use it to restore mysql databases. A backup that isn't easily restored is far less useful. If you are looking for a method to reliably backup mysql data to so you can restore to a mysql server then I think you should stick with the mysqldump tool.

Mysql is free and runs on many different platforms. Setting up a new mysql server that I can restore to is simple. I am not at all worried about not being able to setup mysql so I can do a restore.

I would be far more worried about a custom backup/restore based on a fragile format like csv/tsv failing. Are you sure that all your quotes, commas, or tabs that are in your data would get escaped correctly and then parsed correctly by your restore tool?

If you are looking for a method to extract the data then see several in the other answers.

jQuery UI Datepicker - Multiple Date Selections

I needed to do the same thing, so have written some JavaScript to enable this, using the onSelect and beforeShowDay events. It maintains its own array of selected dates, so unfortunately doesn't integrate with a textbox showing the current date, etc. I'm just using it as an inline control, and I can then query the array for the currently selected dates.
I used this code as a basis.

<script type="text/javascript">
// Maintain array of dates
var dates = new Array();

function addDate(date) {
    if (jQuery.inArray(date, dates) < 0) 
        dates.push(date);
}

function removeDate(index) {
    dates.splice(index, 1);
}

// Adds a date if we don't have it yet, else remove it
function addOrRemoveDate(date) {
    var index = jQuery.inArray(date, dates);
    if (index >= 0) 
        removeDate(index);
    else 
        addDate(date);
}

// Takes a 1-digit number and inserts a zero before it
function padNumber(number) {
    var ret = new String(number);
    if (ret.length == 1) 
        ret = "0" + ret;
    return ret;
}

jQuery(function () {
    jQuery("#datepicker").datepicker({
        onSelect: function (dateText, inst) {
            addOrRemoveDate(dateText);
        },
        beforeShowDay: function (date) {
            var year = date.getFullYear();
            // months and days are inserted into the array in the form, e.g "01/01/2009", but here the format is "1/1/2009"
            var month = padNumber(date.getMonth() + 1);
            var day = padNumber(date.getDate());
            // This depends on the datepicker's date format
            var dateString = month + "/" + day + "/" + year;

            var gotDate = jQuery.inArray(dateString, dates);
            if (gotDate >= 0) {
                // Enable date so it can be deselected. Set style to be highlighted
                return [true, "ui-state-highlight"];
            }
            // Dates not in the array are left enabled, but with no extra style
            return [true, ""];
        }
    });
});
</script>

How to remove a variable from a PHP session array

Try this one:

if(FALSE !== ($key = array_search($_GET['name'],$_SESSION['name'])))
{
    unset($_SESSION['name'][$key]);
}

What is the difference between CMD and ENTRYPOINT in a Dockerfile?

Docker has a default entrypoint which is /bin/sh -c but does not have a default command.

When you run docker like this: docker run -i -t ubuntu bash the entrypoint is the default /bin/sh -c, the image is ubuntu and the command is bash.

The command is run via the entrypoint. i.e., the actual thing that gets executed is /bin/sh -c bash. This allowed Docker to implement RUN quickly by relying on the shell's parser.

Later on, people asked to be able to customize this, so ENTRYPOINT and --entrypoint were introduced.

Everything after ubuntu in the example above is the command and is passed to the entrypoint. When using the CMD instruction, it is exactly as if you were doing docker run -i -t ubuntu <cmd>. <cmd> will be the parameter of the entrypoint.

You will also get the same result if you instead type this command docker run -i -t ubuntu. You will still start a bash shell in the container because of the ubuntu Dockerfile specified a default CMD: CMD ["bash"]

As everything is passed to the entrypoint, you can have a very nice behavior from your images. @Jiri example is good, it shows how to use an image as a "binary". When using ["/bin/cat"] as entrypoint and then doing docker run img /etc/passwd, you get it, /etc/passwd is the command and is passed to the entrypoint so the end result execution is simply /bin/cat /etc/passwd.

Another example would be to have any cli as entrypoint. For instance, if you have a redis image, instead of running docker run redisimg redis -H something -u toto get key, you can simply have ENTRYPOINT ["redis", "-H", "something", "-u", "toto"] and then run like this for the same result: docker run redisimg get key.

Using "&times" word in html changes to ×

You need to escape the ampersand:

<div class="test">&amp;times</div>

&times means a multiplication sign. (Technically it should be &times; but lenient browsers let you omit the ;.)

Android; Check if file exists without creating a new one

It worked for me:

File file = new File(getApplicationContext().getFilesDir(),"whatever.txt");
    if(file.exists()){
       //Do something
    }
    else{
       //Nothing
     }

How to replace comma (,) with a dot (.) using java

Use this:

String str = " 12,12"
str = str.replaceAll("(\\d+)\\,(\\d+)", "$1.$2");
System.out.println("str:"+str); //-> str:12.12

hope help you.

How can I make a button redirect my page to another page?

try

<button onclick="window.location.href='b.php'">Click me</button>

How to move or copy files listed by 'find' command in unix?

find /PATH/TO/YOUR/FILES -name NAME.EXT -exec cp -rfp {} /DST_DIR \;

tsc is not recognized as internal or external command

If you want to run the tsc command from the integrated terminal with the TypeScript module installed locally, you can add the following to your .vscode\settings.json file.

{
  "terminal.integrated.env.windows": { "PATH": "${workspaceFolder}\\node_modules\\.bin;${env:PATH}" }
}

This will prepend the locally installed node module's binary/executable directory (where tsc.cmd is located) to the $env.PATH variable.

What can be the reasons of connection refused errors?

Connection refused means that the port you are trying to connect to is not actually open.

So either you are connecting to the wrong IP address, or to the wrong port, or the server is listening on the wrong port, or is not actually running.

A common mistake is not specifying the port number when binding or connecting in network byte order...

Django -- Template tag in {% if %} block

Sorry for comment in an old post but if you want to use an else if statement this will help you

{% if title == source %}
    Do This
{% elif title == value %}
    Do This
{% else %}
    Do This
{% endif %}

For more info see Django Documentation

Given an array of numbers, return array of products of all other numbers (no division)

To be complete here is the code in Scala:

val list1 = List(1, 2, 3, 4, 5)
for (elem <- list1) println(list1.filter(_ != elem) reduceLeft(_*_))

This will print out the following:

120
60
40
30
24

The program will filter out the current elem (_ != elem); and multiply the new list with reduceLeft method. I think this will be O(n) if you use scala view or Iterator for lazy eval.

Viewing full version tree in git

There is a very good answer to the same question.
Adding following lines to "~/.gitconfig":

[alias]
lg1 = log --graph --abbrev-commit --decorate --date=relative --format=format:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(bold yellow)%d%C(reset)' --all
lg2 = log --graph --abbrev-commit --decorate --format=format:'%C(bold blue)%h%C(reset) - %C(bold cyan)%aD%C(reset) %C(bold green)(%ar)%C(reset)%C(bold yellow)%d%C(reset)%n''          %C(white)%s%C(reset) %C(dim white)- %an%C(reset)' --all
lg = !"git lg1"

What evaluates to True/False in R?

If you think about it, comparing numbers to logical statements doesn't make much sense. However, since 0 is often associated with "Off" or "False" and 1 with "On" or "True", R has decided to allow 1 == TRUE and 0 == FALSE to both be true. Any other numeric-to-boolean comparison should yield false, unless it's something like 3 - 2 == TRUE.

How to use TLS 1.2 in Java 6

You must create your own SSLSocketFactory based on Bouncy Castle. After to use it, pass to the common HttpsConnextion for using this customized SocketFactory.

1. First : Create a TLSConnectionFactory

Here one tips:

1.1 Extend SSLConnectionFactory

1.2 Override this method :

@Override 
public Socket createSocket(Socket socket, final String host, int port, boolean arg3)

This method will call the next internal method,

1.3 Implement an internal method _createSSLSocket(host, tlsClientProtocol);

Here you must create a Socket using TlsClientProtocol . The trick is override ...startHandshake() method calling TlsClientProtocol

 private SSLSocket _createSSLSocket(final String host , final TlsClientProtocol tlsClientProtocol) {
     return new SSLSocket() {    
       .... Override and implement SSLSocket methods,  particulary: 
            startHandshake() {
             }    
     }

     

Important : The full sample how to use TLS Client Protocol is well explained here: Using BouncyCastle for a simple HTTPS query

2. Second : Use this Customized SSLConnextionFactory on common HTTPSConnection.

This is important ! In other samples you can see into the web , u see hard-coded HTTP Commands....so with a customized SSLConnectionFactory u don't need nothing more...

  URL myurl = new URL( "http:// ...URL tha only Works in TLS 1.2);
  HttpsURLConnection  con = (HttpsURLConnection )myurl.openConnection();
  con.setSSLSocketFactory(new TSLSocketConnectionFactory());

Facebook Graph API, how to get users email?

The only way to get the users e-mail address is to request extended permissions on the email field. The user must allow you to see this and you cannot get the e-mail addresses of the user's friends.

http://developers.facebook.com/docs/authentication/permissions

You can do this if you are using Facebook connect by passing scope=email in the get string of your call to the Auth Dialog.

I'd recommend using an SDK instead of file_get_contents as it makes it far easier to perform the Oauth authentication.

Find which version of package is installed with pip

The python function returning just the package version in a machine-readable format:

from importlib.metadata import version 
version('numpy')

Prior to python 3.8:

pip install importlib-metadata 
from importlib_metadata import version
version('numpy')

The bash equivalent (here also invoked from python) would be much more complex (but more robust - see caution below):

import subprocess
def get_installed_ver(pkg_name):
    bash_str="pip freeze | grep -w %s= | awk -F '==' {'print $2'} | tr -d '\n'" %(pkg_name)
    return(subprocess.check_output(bash_str, shell=True).decode())

Sample usage:

# pkg_name="xgboost"
# pkg_name="Flask"
# pkg_name="Flask-Caching"
pkg_name="scikit-learn"

print(get_installed_ver(pkg_name))
>>> 0.22

Note that in both cases pkg_name parameter should contain package name in the format as returned by pip freeze and not as used during import, e.g. scikit-learn not sklearn or Flask-Caching, not flask_caching.

Note that while invoking pip freeze in bash version may seem inefficient, only this method proves to be sufficiently robust to package naming peculiarities and inconsistencies (e.g. underscores vs dashes, small vs large caps, and abbreviations such as sklearn vs scikit-learn).

Caution: in complex environments both variants can return surprise version numbers, inconsistent with what you can actually get during import.

One such problem arises when there are other versions of the package hidden in a user site-packages subfolder. As an illustration of the perils of using version() here's a situation I encountered:

$ pip freeze | grep lightgbm
lightgbm==2.3.1

and

$ python -c "import lightgbm; print(lightgbm.__version__)"
2.3.1

vs.

$ python -c "from importlib_metadata import version; print(version(\"lightgbm\"))"
2.2.3

until you delete the subfolder with the old version (here 2.2.3) from the user folder (only one would normally be preserved by `pip` - the one installed as last with the `--user` switch):

$ ls /home/jovyan/.local/lib/python3.7/site-packages/lightgbm*
/home/jovyan/.local/lib/python3.7/site-packages/lightgbm-2.2.3.dist-info
/home/jovyan/.local/lib/python3.7/site-packages/lightgbm-2.3.1.dist-info

Another problem is having some conda-installed packages in the same environment. If they share dependencies with your pip-installed packages, and versions of these dependencies differ, you may get downgrades of your pip-installed dependencies.

To illustrate, the latest version of numpy available in PyPI on 04-01-2020 was 1.18.0, while at the same time Anaconda's conda-forge channel had only 1.17.3 version on numpy as their latest. So when you installed a basemap package with conda (as second), your previously pip-installed numpy would get downgraded by conda to 1.17.3, and version 1.18.0 would become unavailable to the import function. In this case version() would be right, and pip freeze/conda list wrong:

$ python -c "from importlib_metadata import version; print(version(\"numpy\"))"
1.17.3

$ python -c "import numpy; print(numpy.__version__)"
1.17.3

$ pip freeze | grep numpy
numpy==1.18.0

$ conda list | grep numpy
numpy                     1.18.0                   pypi_0    pypi

SQL Server find and replace specific word in all rows of specific column

UPDATE tblKit
SET number = REPLACE(number, 'KIT', 'CH')
WHERE number like 'KIT%'

or simply this if you are sure that you have no values like this CKIT002

UPDATE tblKit
SET number = REPLACE(number, 'KIT', 'CH')

Flask SQLAlchemy query, specify column names

session.query().with_entities(SomeModel.col1)

is the same as

session.query(SomeModel.col1)

for alias, we can use .label()

session.query(SomeModel.col1.label('some alias name'))

env: node: No such file or directory in mac

I solved it this way:

$ brew uninstall --force node
$ brew uninstall --force npm

after it

$ brew install node

which suggested me to overwrite simlinks

Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink share/doc/node/gdbinit
Target /usr/local/share/doc/node/gdbinit
already exists. You may want to remove it:
  rm '/usr/local/share/doc/node/gdbinit'

To force the link and overwrite all conflicting files:
  brew link --overwrite node

after executing

$ brew link --overwrite node

everything worked again.

Where can I get Google developer key

"Public API access" the key generated there is the key you got to paste into your public static final String DEVELOPER_KEY as part of this writing 26.12.2013 It is not the clientID but you got take the steps mentioned above to obtain one and generate the public api access key.

How to get info on sent PHP curl request

You can also use a proxy tool like Charles to capture the outgoing request headers, data, etc. by passing the proxy details through CURLOPT_PROXY to your curl_setopt_array method.

For example:

$proxy = '127.0.0.1:8888';
$opt = array (
    CURLOPT_URL => "http://www.example.com",
    CURLOPT_PROXY => $proxy,
    CURLOPT_POST => true,
    CURLOPT_VERBOSE => true,
    );

$ch = curl_init();
curl_setopt_array($ch, $opt);
curl_exec($ch);
curl_close($ch);

Sort a list of tuples by 2nd item (integer value)

Adding to Cheeken's answer, This is how you sort a list of tuples by the 2nd item in descending order.

sorted([('abc', 121),('abc', 231),('abc', 148), ('abc',221)],key=lambda x: x[1], reverse=True)

Python: How to get stdout after running os.system?

These answers didn't work for me. I had to use the following:

import subprocess
p = subprocess.Popen(["pwd"], stdout=subprocess.PIPE)
out = p.stdout.read()
print out

Or as a function (using shell=True was required for me on Python 2.6.7 and check_output was not added until 2.7, making it unusable here):

def system_call(command):
    p = subprocess.Popen([command], stdout=subprocess.PIPE, shell=True)
    return p.stdout.read()

Get free disk space

see this article!

  1. identify UNC par or local drive path by searching index of ":"

  2. if its is UNC PATH you cam map UNC path

  3. code to execute drive name is mapped drive name < UNC Mapped Drive or Local Drive>.

    using System.IO;
    
    private long GetTotalFreeSpace(string driveName)
    {
    foreach (DriveInfo drive in DriveInfo.GetDrives())
    {
        if (drive.IsReady && drive.Name == driveName)
        {
            return drive.TotalFreeSpace;
        }
    }
    return -1;
    }
    
  4. unmap after you requirement done.

Find a line in a file and remove it

    public static void deleteLine() throws IOException {
        RandomAccessFile file = new RandomAccessFile("me.txt", "rw");
        String delete;
        String task="";
        byte []tasking;
        while ((delete = file.readLine()) != null) {
            if (delete.startsWith("BAD")) {
                continue;
            }
            task+=delete+"\n";
        }
        System.out.println(task);
        BufferedWriter writer = new BufferedWriter(new FileWriter("me.txt"));
        writer.write(task);
        file.close();
        writer.close();
    }

Selenium wait until document is ready

Here's something similar, in Ruby:

wait = Selenium::WebDriver::Wait.new(:timeout => 10)
wait.until { @driver.execute_script('return document.readyState').eql?('complete') }

android layout with visibility GONE

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/activity_register_header"
    android:minHeight="50dp"
    android:orientation="vertical"
    android:visibility="gone" />

Try this piece of code..For me this code worked..

Bootstrap 4 Center Vertical and Horizontal Alignment

This work for me:

<section class="h-100">
  <header class="container h-100">
    <div class="d-flex align-items-center justify-content-center h-100">
      <div class="d-flex flex-column">
        <h1 class="text align-self-center p-2">item 1</h1>
        <h4 class="text align-self-center p-2">item 2</h4>
        <button class="btn btn-danger align-self-center p-2" type="button" name="button">item 3</button>
      </div>
    </div>
  </header>
</section>

How to select date from datetime column?

Using WHERE DATE(datetime) = '2009-10-20' has performance issues. As stated here:

  • it will calculate DATE() for all rows, including those that don't match.
  • it will make it impossible to use an index for the query.

Use BETWEEN or >, <, = operators which allow to use an index:

SELECT * FROM data 
WHERE datetime BETWEEN '2009-10-20 00:00:00' AND '2009-10-20 23:59:59'

Update: the impact on using LIKE instead of operators in an indexed column is high. These are some test results on a table with 1,176,000 rows:

  • using datetime LIKE '2009-10-20%' => 2931ms
  • using datetime >= '2009-10-20 00:00:00' AND datetime <= '2009-10-20 23:59:59' => 168ms

When doing a second call over the same query the difference is even higher: 2984ms vs 7ms (yes, just 7 milliseconds!). I found this while rewriting some old code on a project using Hibernate.

Properties order in Margin

There are three unique situations:

  • 4 numbers, e.g. Margin="a,b,c,d".
  • 2 numbers, e.g. Margin="a,b".
  • 1 number, e.g. Margin="a".

4 Numbers

If there are 4 numbers, then its left, top, right, bottom (a clockwise circle starting from the middle left margin). First number is always the "West" like "WPF":

<object Margin="left,top,right,bottom"/>

Example: if we use Margin="10,20,30,40" it generates:

enter image description here

2 Numbers

If there are 2 numbers, then the first is left & right margin thickness, the second is top & bottom margin thickness. First number is always the "West" like "WPF":

<object Margin="a,b"/> // Equivalent to Margin="a,b,a,b".

Example: if we use Margin="10,30", the left & right margin are both 10, and the top & bottom are both 30.

enter image description here

1 Number

If there is 1 number, then the number is repeated (its essentially a border thickness).

<object Margin="a"/> // Equivalent to Margin="a,a,a,a".

Example: if we use Margin="20" it generates:

enter image description here

Update 2020-05-27

Have been working on a large-scale WPF application for the past 5 years with over 100 screens. Part of a team of 5 WPF/C#/Java devs. We eventually settled on either using 1 number (for border thickness) or 4 numbers. We never use 2. It is consistent, and seems to be a good way to reduce cognitive load when developing.


The rule:

All width numbers start on the left (the "West" like "WPF") and go clockwise (if two numbers, only go clockwise twice, then mirror the rest).

Using a dictionary to select function to execute

You are wasting your time:

  1. You are about to write a lot of useless code and introduce new bugs.
  2. To execute the function, your user will need to know the P1 name anyway.
  3. Etc., etc., etc.

Just put all your functions in the .py file:

# my_module.py

def f1():
    pass

def f2():
    pass

def f3():
    pass

And use them like this:

import my_module

my_module.f1()
my_module.f2()
my_module.f3()

or:

from my_module import f1
from my_module import f2
from my_module import f3

f1()
f2()
f3()

This should be enough for starters.

Get pandas.read_csv to read empty values as empty string instead of nan

I added a ticket to add an option of some sort here:

https://github.com/pydata/pandas/issues/1450

In the meantime, result.fillna('') should do what you want

EDIT: in the development version (to be 0.8.0 final) if you specify an empty list of na_values, empty strings will stay empty strings in the result

how to create a cookie and add to http response from inside my service layer?

Following @Aravind's answer with more details

@RequestMapping("/myPath.htm")
public ModelAndView add(HttpServletRequest request, HttpServletResponse response) throws Exception{
    myServiceMethodSettingCookie(request, response);        //Do service call passing the response
    return new ModelAndView("CustomerAddView");
}

// service method
void myServiceMethodSettingCookie(HttpServletRequest request, HttpServletResponse response){
    final String cookieName = "my_cool_cookie";
    final String cookieValue = "my cool value here !";  // you could assign it some encoded value
    final Boolean useSecureCookie = false;
    final int expiryTime = 60 * 60 * 24;  // 24h in seconds
    final String cookiePath = "/";

    Cookie cookie = new Cookie(cookieName, cookieValue);

    cookie.setSecure(useSecureCookie);  // determines whether the cookie should only be sent using a secure protocol, such as HTTPS or SSL

    cookie.setMaxAge(expiryTime);  // A negative value means that the cookie is not stored persistently and will be deleted when the Web browser exits. A zero value causes the cookie to be deleted.

    cookie.setPath(cookiePath);  // The cookie is visible to all the pages in the directory you specify, and all the pages in that directory's subdirectories

    response.addCookie(cookie);
}

Related docs:

http://docs.oracle.com/javaee/7/api/javax/servlet/http/Cookie.html

http://docs.spring.io/spring-security/site/docs/3.0.x/reference/springsecurity.html

matplotlib: how to change data points color based on some variable

This is what matplotlib.pyplot.scatter is for.

As a quick example:

import matplotlib.pyplot as plt
import numpy as np

# Generate data...
t = np.linspace(0, 2 * np.pi, 20)
x = np.sin(t)
y = np.cos(t)

plt.scatter(t,x,c=y)
plt.show()

enter image description here

how to auto select an input field and the text in it on page load

Using the autofocus attribute works well with text input and checkboxes.

<input type="text" name="foo" value="boo" autofocus="autofocus"> FooBoo
<input type="checkbox" name="foo" value="boo" autofocus="autofocus"> FooBoo

Round a floating-point number down to the nearest integer?

It may be very simple, but couldn't you just round it up then minus 1? For example:

number=1.5
round(number)-1
> 1

How to get current PHP page name

In your case you can use __FILE__ variable !
It should help.
It is one of predefined.
Read more about predefined constants in PHP http://php.net/manual/en/language.constants.predefined.php

Ternary operators in JavaScript without an "else"

You could write

x = condition ? true : x;

So that x is unmodified when the condition is false.

This then is equivalent to

if (condition) x = true

EDIT:

!defaults.slideshowWidth 
      ? defaults.slideshowWidth = obj.find('img').width()+'px' 
      : null 

There are a couple of alternatives - I'm not saying these are better/worse - merely alternatives

Passing in null as the third parameter works because the existing value is null. If you refactor and change the condition, then there is a danger that this is no longer true. Passing in the exising value as the 2nd choice in the ternary guards against this:

!defaults.slideshowWidth = 
      ? defaults.slideshowWidth = obj.find('img').width()+'px' 
      : defaults.slideshowwidth 

Safer, but perhaps not as nice to look at, and more typing. In practice, I'd probably write

defaults.slideshowWidth = defaults.slideshowWidth 
               || obj.find('img').width()+'px'

How to start up spring-boot application via command line?

1.Run Spring Boot app with java -jar command

To run your Spring Boot app from a command line in a Terminal window you can use java -jar command. This is provided your Spring Boot app was packaged as an executable jar file.

java -jar target/app-0.0.1-SNAPSHOT.jar

2.Run Spring Boot app using Maven

You can also use Maven plugin to run your Spring Boot app. Use the below command to run your Spring Boot app with Maven plugin:

mvn spring-boot:run

3.Run Spring Boot App with Gradle

And if you use Gradle you can run the Spring Boot app with the following command:

gradle bootRun

Apache shows PHP code instead of executing it

open the file

/etc/apache2/httpd.conf

and change

#LoadModule php5_module libexec/apache2/libphp5.so

into

LoadModule php5_module libexec/apache2/libphp5.so

So just uncoment the PHP module load in httpd.conf

New line in JavaScript alert box

When you want to write in javascript alert from a php variable, you have to add an other "\" before "\n". Instead the alert pop-up is not working.

ex:

PHP :
$text = "Example Text : \n"
$text2 = "Example Text : \\n"

JS:
window.alert('<?php echo $text; ?>');  // not working
window.alert('<?php echo $text2; ?>');  // is working

How to find the kafka version in linux

go to kafka/libs folder we can see multiple jars search for something similar kafka_2.11-0.10.1.1.jar.asc in this case the kafka version is 0.10.1.1

How to set Java classpath in Linux?

export CLASSPATH=/home/appnetix/LOG4J_HOME/log4j-1.2.16.jar

or, if you already have some classpath set

export CLASSPATH=$CLASSPATH:/home/appnetix/LOG4J_HOME/log4j-1.2.16.jar

and, if also you want to include current directory

export CLASSPATH=$CLASSPATH:/home/appnetix/LOG4J_HOME/log4j-1.2.16.jar:.

How to monitor Java memory usage?

There are tools that let you monitor the VM's memory usage. The VM can expose memory statistics using JMX. You can also print GC statistics to see how the memory is performing over time.

Invoking System.gc() can harm the GC's performance because objects will be prematurely moved from the new to old generations, and weak references will be cleared prematurely. This can result in decreased memory efficiency, longer GC times, and decreased cache hits (for caches that use weak refs). I agree with your consultant: System.gc() is bad. I'd go as far as to disable it using the command line switch.

How to convert currentTimeMillis to a date in Java?

You can try java.time api;

        Instant date = Instant.ofEpochMilli(1549362600000l);
        LocalDateTime utc = LocalDateTime.ofInstant(date, ZoneOffset.UTC);

How to loop through an array of objects in swift

You can try using the simple NSArray in syntax for iterating over the array in swift which makes for shorter code. The following is working for me:

class ModelAttachment {
    var id: String?
    var url: String?
    var thumb: String?
}

var modelAttachementObj = ModelAttachment()
modelAttachementObj.id = "1"
modelAttachementObj.url = "http://www.google.com"
modelAttachementObj.thumb = "thumb"

var imgs: Array<ModelAttachment> = [modelAttachementObj]

for img in imgs  {
    let url = img.url
    NSLog(url!)
}

See docs here

How to implement __iter__(self) for a container object (Python)

Another option is to inherit from the appropriate abstract base class from the `collections module as documented here.

In case the container is its own iterator, you can inherit from collections.Iterator. You only need to implement the next method then.

An example is:

>>> from collections import Iterator
>>> class MyContainer(Iterator):
...     def __init__(self, *data):
...         self.data = list(data)
...     def next(self):
...         if not self.data:
...             raise StopIteration
...         return self.data.pop()
...         
...     
... 
>>> c = MyContainer(1, "two", 3, 4.0)
>>> for i in c:
...     print i
...     
... 
4.0
3
two
1

While you are looking at the collections module, consider inheriting from Sequence, Mapping or another abstract base class if that is more appropriate. Here is an example for a Sequence subclass:

>>> from collections import Sequence
>>> class MyContainer(Sequence):
...     def __init__(self, *data):
...         self.data = list(data)
...     def __getitem__(self, index):
...         return self.data[index]
...     def __len__(self):
...         return len(self.data)
...         
...     
... 
>>> c = MyContainer(1, "two", 3, 4.0)
>>> for i in c:
...     print i
...     
... 
1
two
3
4.0

NB: Thanks to Glenn Maynard for drawing my attention to the need to clarify the difference between iterators on the one hand and containers that are iterables rather than iterators on the other.

How to build a 2 Column (Fixed - Fluid) Layout with Twitter Bootstrap?

Update 2018

Bootstrap 4

Now that BS4 is flexbox, the fixed-fluid is simple. Just set the width of the fixed column, and use the .col class on the fluid column.

.sidebar {
    width: 180px;
    min-height: 100vh;
}

<div class="row">
    <div class="sidebar p-2">Fixed width</div>
    <div class="col bg-dark text-white pt-2">
        Content
    </div>
</div>

http://www.codeply.com/go/7LzXiPxo6a

Bootstrap 3..

One approach to a fixed-fluid layout is using media queries that align with Bootstrap's breakpoints so that you only use the fixed width columns are larger screens and then let the layout stack responsively on smaller screens...

@media (min-width:768px) {
  #sidebar {
      min-width: 300px;
      max-width: 300px;
  }
  #main {
      width:calc(100% - 300px);
  }
}

Working Bootstrap 3 Fixed-Fluid Demo

Related Q&A:
Fixed width column with a container-fluid in bootstrap
How to left column fixed and right scrollable in Bootstrap 4, responsive?

How can I force a long string without any blank to be wrapped?

I don't think you can do this with CSS. Instead, at regular 'word lengths' along the string, insert an HTML soft-hyphen:

ACTGATCG&shy;AGCTGAAG&shy;CGCAGTGC&shy;GATGCTTC&shy;GATGATGC&shy;TGACGATG

This will display a hyphen at the end of the line, where it wraps, which may or may not be what you want.

Note Safari seems to wrap the long string in a <textarea> anyway, unlike Firefox.

Creating a Shopping Cart using only HTML/JavaScript

I think it is a better idea to start working with a raw data and then translate it to DOM (document object model)

I would suggest you to work with array of objects and then output it to the DOM in order to accomplish your task.

You can see working example of following code at http://www.softxml.com/stackoverflow/shoppingCart.htm

You can try following approach:

//create array that will hold all ordered products
    var shoppingCart = [];

    //this function manipulates DOM and displays content of our shopping cart
    function displayShoppingCart(){
        var orderedProductsTblBody=document.getElementById("orderedProductsTblBody");
        //ensure we delete all previously added rows from ordered products table
        while(orderedProductsTblBody.rows.length>0) {
            orderedProductsTblBody.deleteRow(0);
        }

        //variable to hold total price of shopping cart
        var cart_total_price=0;
        //iterate over array of objects
        for(var product in shoppingCart){
            //add new row      
            var row=orderedProductsTblBody.insertRow();
            //create three cells for product properties 
            var cellName = row.insertCell(0);
            var cellDescription = row.insertCell(1);
            var cellPrice = row.insertCell(2);
            cellPrice.align="right";
            //fill cells with values from current product object of our array
            cellName.innerHTML = shoppingCart[product].Name;
            cellDescription.innerHTML = shoppingCart[product].Description;
            cellPrice.innerHTML = shoppingCart[product].Price;
            cart_total_price+=shoppingCart[product].Price;
        }
        //fill total cost of our shopping cart 
        document.getElementById("cart_total").innerHTML=cart_total_price;
    }


    function AddtoCart(name,description,price){
       //Below we create JavaScript Object that will hold three properties you have mentioned:    Name,Description and Price
       var singleProduct = {};
       //Fill the product object with data
       singleProduct.Name=name;
       singleProduct.Description=description;
       singleProduct.Price=price;
       //Add newly created product to our shopping cart 
       shoppingCart.push(singleProduct);
       //call display function to show on screen
       displayShoppingCart();

    }  


    //Add some products to our shopping cart via code or you can create a button with onclick event
    //AddtoCart("Table","Big red table",50);
    //AddtoCart("Door","Big yellow door",150);
    //AddtoCart("Car","Ferrari S23",150000);






<table cellpadding="4" cellspacing="4" border="1">
    <tr>
        <td valign="top">
            <table cellpadding="4" cellspacing="4" border="0">
                <thead>
                    <tr>
                        <td colspan="2">
                            Products for sale
                        </td>
                    </tr>
                </thead>
                <tbody>
                    <tr>
                        <td>
                            Table
                        </td>
                        <td>
                            <input type="button" value="Add to cart" onclick="AddtoCart('Table','Big red table',50)"/>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Door
                        </td>
                        <td>
                            <input type="button" value="Add to cart" onclick="AddtoCart('Door','Yellow Door',150)"/>
                        </td>
                    </tr>
                    <tr>
                        <td>
                            Car
                        </td>
                        <td>
                            <input type="button" value="Add to cart" onclick="AddtoCart('Ferrari','Ferrari S234',150000)"/>
                        </td>
                    </tr>
                </tbody>

            </table>
        </td>
        <td valign="top">
            <table cellpadding="4" cellspacing="4" border="1" id="orderedProductsTbl">
                <thead>
                    <tr>
                        <td>
                            Name
                        </td>
                        <td>
                            Description
                        </td>
                        <td>
                            Price
                        </td>
                    </tr>
                </thead>
                <tbody id="orderedProductsTblBody">

                </tbody>
                <tfoot>
                    <tr>
                        <td colspan="3" align="right" id="cart_total">

                        </td>
                    </tr>
                </tfoot>
            </table>
        </td>
    </tr>
</table>

Please have a look at following free client-side shopping cart:

SoftEcart(js) is a Responsive, Handlebars & JSON based, E-Commerce shopping cart written in JavaScript with built-in PayPal integration.

Documentation

http://www.softxml.com/softecartjs-demo/documentation/SoftecartJS_free.html

Hope you will find it useful.

C# generic list <T> how to get the type of T?

Given an object which I suspect to be some kind of IList<>, how can I determine of what it's an IList<>?

Here's a reliable solution. My apologies for length - C#'s introspection API makes this suprisingly difficult.

/// <summary>
/// Test if a type implements IList of T, and if so, determine T.
/// </summary>
public static bool TryListOfWhat(Type type, out Type innerType)
{
    Contract.Requires(type != null);

    var interfaceTest = new Func<Type, Type>(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IList<>) ? i.GetGenericArguments().Single() : null);

    innerType = interfaceTest(type);
    if (innerType != null)
    {
        return true;
    }

    foreach (var i in type.GetInterfaces())
    {
        innerType = interfaceTest(i);
        if (innerType != null)
        {
            return true;
        }
    }

    return false;
}

Example usage:

    object value = new ObservableCollection<int>();
Type innerType;
TryListOfWhat(value.GetType(), out innerType).Dump();
innerType.Dump();

Returns

True
typeof(Int32)

How to close jQuery Dialog within the dialog?

Close from iframe inside a dialog:

window.parent.$('.ui-dialog-content:visible').dialog('close');

Find all files in a directory with extension .txt in Python

Use fnmatch: https://docs.python.org/2/library/fnmatch.html

import fnmatch
import os

for file in os.listdir('.'):
    if fnmatch.fnmatch(file, '*.txt'):
        print file

What is the JUnit XML format specification that Hudson supports?

The top answer of the question Anders Lindahl refers to an xsd file.

Personally I found this xsd file also very useful (I don't remember how I found that one). It looks a bit less intimidating, and as far as I used it, all the elements and attributes seem to be recognized by Jenkins (v1.451)

One thing though: when adding multiple <failure ... elements, only one was retained in Jenkins. When creating the xml file, I now concatenate all the failures in one.


Update 2016-11 The link is broken now. A better alternative is this page from cubic.org: JUnit XML reporting file format, where a nice effort has been taken to provide a sensible documented example. Example and xsd are copied below, but their page looks waay nicer.


sample JUnit XML file

<?xml version="1.0" encoding="UTF-8"?>
<!-- a description of the JUnit XML format and how Jenkins parses it. See also junit.xsd -->

<!-- if only a single testsuite element is present, the testsuites
     element can be omitted. All attributes are optional. -->
<testsuites disabled="" <!-- total number of disabled tests from all testsuites. -->
            errors=""   <!-- total number of tests with error result from all testsuites. -->
            failures="" <!-- total number of failed tests from all testsuites. -->
            name=""
            tests=""    <!-- total number of successful tests from all testsuites. -->
            time=""     <!-- time in seconds to execute all test suites. -->
        >

  <!-- testsuite can appear multiple times, if contained in a testsuites element.
       It can also be the root element. -->
  <testsuite name=""      <!-- Full (class) name of the test for non-aggregated testsuite documents.
                               Class name without the package for aggregated testsuites documents. Required -->
         tests=""     <!-- The total number of tests in the suite, required. -->
         disabled=""  <!-- the total number of disabled tests in the suite. optional -->
             errors=""    <!-- The total number of tests in the suite that errored. An errored test is one that had an unanticipated problem,
                               for example an unchecked throwable; or a problem with the implementation of the test. optional -->
             failures=""  <!-- The total number of tests in the suite that failed. A failure is a test which the code has explicitly failed
                               by using the mechanisms for that purpose. e.g., via an assertEquals. optional -->
             hostname=""  <!-- Host on which the tests were executed. 'localhost' should be used if the hostname cannot be determined. optional -->
         id=""        <!-- Starts at 0 for the first testsuite and is incremented by 1 for each following testsuite -->
         package=""   <!-- Derived from testsuite/@name in the non-aggregated documents. optional -->
         skipped=""   <!-- The total number of skipped tests. optional -->
         time=""      <!-- Time taken (in seconds) to execute the tests in the suite. optional -->
         timestamp="" <!-- when the test was executed in ISO 8601 format (2014-01-21T16:17:18). Timezone may not be specified. optional -->
         >

    <!-- Properties (e.g., environment settings) set during test
     execution. The properties element can appear 0 or once. -->
    <properties>
      <!-- property can appear multiple times. The name and value attributres are required. -->
      <property name="" value=""/>
    </properties>

    <!-- testcase can appear multiple times, see /testsuites/testsuite@tests -->
    <testcase name=""       <!-- Name of the test method, required. -->
          assertions="" <!-- number of assertions in the test case. optional -->
          classname=""  <!-- Full class name for the class the test method is in. required -->
          status=""
          time=""       <!-- Time taken (in seconds) to execute the test. optional -->
          >

      <!-- If the test was not executed or failed, you can specify one
           the skipped, error or failure elements. -->

      <!-- skipped can appear 0 or once. optional -->
      <skipped/>

      <!-- Indicates that the test errored. An errored test is one
           that had an unanticipated problem. For example an unchecked
           throwable or a problem with the implementation of the
           test. Contains as a text node relevant data for the error,
           for example a stack trace. optional -->
      <error message="" <!-- The error message. e.g., if a java exception is thrown, the return value of getMessage() -->
         type=""    <!-- The type of error that occured. e.g., if a java execption is thrown the full class name of the exception. -->
         ></error>

      <!-- Indicates that the test failed. A failure is a test which
       the code has explicitly failed by using the mechanisms for
       that purpose. For example via an assertEquals. Contains as
       a text node relevant data for the failure, e.g., a stack
       trace. optional -->
      <failure message="" <!-- The message specified in the assert. -->
           type=""    <!-- The type of the assert. -->
           ></failure>

      <!-- Data that was written to standard out while the test was executed. optional -->
      <system-out></system-out>

      <!-- Data that was written to standard error while the test was executed. optional -->
      <system-err></system-err>
    </testcase>

    <!-- Data that was written to standard out while the test suite was executed. optional -->
    <system-out></system-out>
    <!-- Data that was written to standard error while the test suite was executed. optional -->
    <system-err></system-err>
  </testsuite>
</testsuites>

JUnit XSD file

<?xml version="1.0" encoding="UTF-8" ?>
<!-- from https://svn.jenkins-ci.org/trunk/hudson/dtkit/dtkit-format/dtkit-junit-model/src/main/resources/com/thalesgroup/dtkit/junit/model/xsd/junit-4.xsd -->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

    <xs:element name="failure">
        <xs:complexType mixed="true">
            <xs:attribute name="type" type="xs:string" use="optional"/>
            <xs:attribute name="message" type="xs:string" use="optional"/>
        </xs:complexType>
    </xs:element>

    <xs:element name="error">
        <xs:complexType mixed="true">
            <xs:attribute name="type" type="xs:string" use="optional"/>
            <xs:attribute name="message" type="xs:string" use="optional"/>
        </xs:complexType>
    </xs:element>

    <xs:element name="properties">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="property" maxOccurs="unbounded"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:element name="property">
        <xs:complexType>
            <xs:attribute name="name" type="xs:string" use="required"/>
            <xs:attribute name="value" type="xs:string" use="required"/>
        </xs:complexType>
    </xs:element>

    <xs:element name="skipped" type="xs:string"/>
    <xs:element name="system-err" type="xs:string"/>
    <xs:element name="system-out" type="xs:string"/>

    <xs:element name="testcase">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="skipped" minOccurs="0" maxOccurs="1"/>
                <xs:element ref="error" minOccurs="0" maxOccurs="unbounded"/>
                <xs:element ref="failure" minOccurs="0" maxOccurs="unbounded"/>
                <xs:element ref="system-out" minOccurs="0" maxOccurs="unbounded"/>
                <xs:element ref="system-err" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
            <xs:attribute name="name" type="xs:string" use="required"/>
            <xs:attribute name="assertions" type="xs:string" use="optional"/>
            <xs:attribute name="time" type="xs:string" use="optional"/>
            <xs:attribute name="classname" type="xs:string" use="optional"/>
            <xs:attribute name="status" type="xs:string" use="optional"/>
        </xs:complexType>
    </xs:element>

    <xs:element name="testsuite">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="properties" minOccurs="0" maxOccurs="1"/>
                <xs:element ref="testcase" minOccurs="0" maxOccurs="unbounded"/>
                <xs:element ref="system-out" minOccurs="0" maxOccurs="1"/>
                <xs:element ref="system-err" minOccurs="0" maxOccurs="1"/>
            </xs:sequence>
            <xs:attribute name="name" type="xs:string" use="required"/>
            <xs:attribute name="tests" type="xs:string" use="required"/>
            <xs:attribute name="failures" type="xs:string" use="optional"/>
            <xs:attribute name="errors" type="xs:string" use="optional"/>
            <xs:attribute name="time" type="xs:string" use="optional"/>
            <xs:attribute name="disabled" type="xs:string" use="optional"/>
            <xs:attribute name="skipped" type="xs:string" use="optional"/>
            <xs:attribute name="timestamp" type="xs:string" use="optional"/>
            <xs:attribute name="hostname" type="xs:string" use="optional"/>
            <xs:attribute name="id" type="xs:string" use="optional"/>
            <xs:attribute name="package" type="xs:string" use="optional"/>
        </xs:complexType>
    </xs:element>

    <xs:element name="testsuites">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="testsuite" minOccurs="0" maxOccurs="unbounded"/>
            </xs:sequence>
            <xs:attribute name="name" type="xs:string" use="optional"/>
            <xs:attribute name="time" type="xs:string" use="optional"/>
            <xs:attribute name="tests" type="xs:string" use="optional"/>
            <xs:attribute name="failures" type="xs:string" use="optional"/>
            <xs:attribute name="disabled" type="xs:string" use="optional"/>
            <xs:attribute name="errors" type="xs:string" use="optional"/>
        </xs:complexType>
    </xs:element>

</xs:schema>

Implement specialization in ER diagram

So I assume your permissions table has a foreign key reference to admin_accounts table. If so because of referential integrity you will only be able to add permissions for account ids exsiting in the admin accounts table. Which also means that you wont be able to enter a user_account_id [assuming there are no duplicates!]

Saving timestamp in mysql table using php

Check field type in table just save time stamp value in datatype like bigint etc.

Not datetime type

Converting .NET DateTime to JSON

If you pass a DateTime from a .Net code to a javascript code, C#:

DateTime net_datetime = DateTime.Now;

javascript treats it as a string, like "/Date(1245398693390)/":

You can convert it as fllowing:

// convert the string to date correctly
var d = eval(net_datetime.slice(1, -1))

or:

// convert the string to date correctly
var d = eval("/Date(1245398693390)/".slice(1, -1))

How to get id from URL in codeigniter?

$product_id = $this->input->get('id', TRUE);
echo $product_id;

How can I check if a scrollbar is visible?

Ugh everyone's answers on here are incomplete, and lets stop using jquery in SO answers already please. Check jquery's documentation if you want info on jquery.

Here's a generalized pure-javascript function for testing whether or not an element has scrollbars in a complete way:

// dimension - Either 'y' or 'x'
// computedStyles - (Optional) Pass in the domNodes computed styles if you already have it (since I hear its somewhat expensive)
function hasScrollBars(domNode, dimension, computedStyles) {
    dimension = dimension.toUpperCase()
    if(dimension === 'Y') {
        var length = 'Height'
    } else {
        var length = 'Width'
    }

    var scrollLength = 'scroll'+length
    var clientLength = 'client'+length
    var overflowDimension = 'overflow'+dimension

    var hasVScroll = domNode[scrollLength] > domNode[clientLength]


    // Check the overflow and overflowY properties for "auto" and "visible" values
    var cStyle = computedStyles || getComputedStyle(domNode)
    return hasVScroll && (cStyle[overflowDimension] == "visible"
                         || cStyle[overflowDimension] == "auto"
                         )
          || cStyle[overflowDimension] == "scroll"
}

Where is the Keytool application?

If you are working with a Mac... the keytool is part of the Java SDK and can be found in the following location /System/Library/Java/JavaVirtualMachines/[VERSION].jdk/Contents/Home/bin/keytool

Cannot implicitly convert type 'System.DateTime?' to 'System.DateTime'. An explicit conversion exists

you should be using the .Value of the datetime parameter. All Nullable structs have a value property which returns the concrete type of the object. but you must check to see if it is null beforehand otherwise you will get a runtime error.

i.e:

datetime.Value

but check to see if it has a value first!

if (datetime.HasValue)
{
   // work with datetime.Value
}

How to symbolicate crash log Xcode?

There is an easier way using Xcode (without using command line tools and looking up addresses one at a time)

  1. Take any .xcarchive file. If you have one from before you can use that. If you don't have one, create one by running the Product > Archive from Xcode.

  2. Right click on the .xcarchive file and select 'Show Package Contents'

  3. Copy the dsym file (of the version of the app that crashed) to the dSYMs folder

  4. Copy the .app file (of the version of the app that crashed) to the Products > Applications folder

  5. Edit the Info.plist and edit the CFBundleShortVersionString and CFBundleVersion under the ApplicationProperties dictionary. This will help you identify the archive later

  6. Double click the .xcarchive to import it to Xcode. It should open Organizer.

  7. Go back to the crash log (in Devices window in Xcode)

  8. Drag your .crash file there (if not already present)

  9. The entire crash log should now be symbolicated. If not, then right click and select 'Re-symbolicate crash log'

Changing the Git remote 'push to' default

If you did git push origin -u localBranchName:remoteBranchName and on sequentially git push commands, you get errors that then origin doesn't exist, then follow these steps:

  1. git remote -v

Check if there is any remote that I don't care. Delete them with git remote remove 'name'

  1. git config --edit

Look for possible signs of a old/non-existent remote. Look for pushdefault:

[remote]
  pushdefault = oldremote

Update oldremote value and save.

git push should work now.

gcc/g++: "No such file or directory"

this works for me, sudo apt-get install libx11-dev

Creating NSData from NSString in Swift

Swift 4

let data = myStringVariable.data(using: String.Encoding.utf8.rawValue)

How do I install cURL on cygwin?

In the Cygwin package manager, click on curl from within the "net" category. Yes, it's that simple.

Detect Browser Language in PHP

Unfortunately, none of the answers to this question takes into account some valid HTTP_ACCEPT_LANGUAGE such as:

  • q=0.8,en-US;q=0.5,en;q=0.3: having the q priority value at first place.
  • ZH-CN: old browsers that capitalise (wrongly) the whole langcode.
  • *: that basically say "serve whatever language you have".

After a comprehensive test with thousands of different Accept-Languages in my server, I ended up having this language detection method:

define('SUPPORTED_LANGUAGES', ['en', 'es']);

function detect_language() {
    foreach (preg_split('/[;,]/', $_SERVER['HTTP_ACCEPT_LANGUAGE']) as $sub) {
        if (substr($sub, 0, 2) == 'q=') continue;
        if (strpos($sub, '-') !== false) $sub = explode('-', $sub)[0];
        if (in_array(strtolower($sub), SUPPORTED_LANGUAGES)) return $sub;
    }
    return 'en';
}

Customize list item bullets using CSS

Another way of changing the size of the bullets would be:

  1. Disabling the bullets altogether
  2. Re-adding the custom bullets with the help of ::before pseudo-element.

Example:

_x000D_
_x000D_
ul {_x000D_
  list-style-type: none;_x000D_
}_x000D_
_x000D_
li::before {_x000D_
  display:          inline-block;_x000D_
  vertical-align:   middle;_x000D_
  width:            5px;_x000D_
  height:           5px;_x000D_
  background-color: #000000;_x000D_
  margin-right:     8px;_x000D_
  content:          ' '_x000D_
}
_x000D_
<ul>_x000D_
  <li>first element</li>_x000D_
  <li>second element</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

No markup changes needed

Best way to add Activity to an Android project in Eclipse?

I just use the "New Class" dialog in Eclipse and set the base class as Activity. I'm not aware of any other way to do this. What other method would you expect to be available?

How to initialize an array's length in JavaScript?

  1. Why do you want to initialize the length? Theoretically there is no need for this. It can even result in confusing behavior, because all tests that use the length to find out whether an array is empty or not will report that the array is not empty.
    Some tests show that setting the initial length of large arrays can be more efficient if the array is filled afterwards, but the performance gain (if any) seem to differ from browser to browser.

  2. jsLint does not like new Array() because the constructer is ambiguous.

    new Array(4);
    

    creates an empty array of length 4. But

    new Array('4');
    

    creates an array containing the value '4'.

Regarding your comment: In JS you don't need to initialize the length of the array. It grows dynamically. You can just store the length in some variable, e.g.

var data = [];
var length = 5; // user defined length

for(var i = 0; i < length; i++) {
    data.push(createSomeObject());
}

What's the difference between Apache's Mesos and Google's Kubernetes

Both projects aim to make it easier to deploy & manage applications inside containers in your datacenter or cloud.

In order to deploy applications on top of Mesos, one can use Marathon or Kubernetes for Mesos.

Marathon is a cluster-wide init and control system for running Linux services in cgroups and Docker containers. Marathon has a number of different canary deploy features and is a very mature project.

Marathon runs on top of Mesos, which is a highly scalable, battle tested and flexible resource manager. Marathon is proven to scale and runs in many production environments.

The Mesos and Mesosphere technology stack provides a cloud-like environment for running existing Linux workloads, but it also provides a native environment for building new distributed systems.

Mesos is a distributed systems kernel, with a full API for programming directly against the datacenter. It abstracts underlying hardware (e.g. bare metal or VMs) away and just exposes the resources. It contains primitives for writing distributed applications (e.g. Spark was originally a Mesos App, Chronos, etc.) such as Message Passing, Task Execution, etc. Thus, entirely new applications are made possible. Apache Spark is one example for a new (in Mesos jargon called) framework that was built originally for Mesos. This enabled really fast development - the developers of Spark didn't have to worry about networking to distribute tasks amongst nodes as this is a core primitive in Mesos.

To my knowledge, Kubernetes is not used inside Google in production deployments today. For production, Google uses Omega/Borg, which is much more similar to the Mesos/Marathon model. However the great thing about using Mesos as the foundation is that both Kubernetes and Marathon can run on top of it.

More resources about Marathon:

https://mesosphere.github.io/marathon/

Video: https://www.youtube.com/watch?v=hZNGST2vIds

How to get source code of a Windows executable?

If the program was written in C# you can get the source code in almost its original form using .NET Reflector. You won't be able to see comments and local variable names, but it is very readable.

If it was written C++ it's not so easy... even if you could decompile the code into valid C++ it is unlikely that it will resemble the original source because of inlined functions and optimizations which are hard to reverse.

Please note that by reverse engineering and modifying the source code you might breaking the terms of use of the programs unless you wrote them yourself or have permission from the author.

Prevent linebreak after </div>

.label, .text {display: inline}

Although if you use that, you might as well change the div's to span's.

ORA-28040: No matching authentication protocol exception

Here is some text I found at experts-exchange:

Bug 14575666

In 12.1, the default value for the SQLNET.ALLOWED_LOGON_VERSION parameter has been updated to 11. This means that database clients using pre-11g JDBC thin drivers cannot authenticate to 12.1 database servers unless theSQLNET.ALLOWED_LOGON_VERSION parameter is set to the old default of 8.

This will cause a 10.2.0.5 Oracle RAC database creation using DBCA to fail with the ORA-28040: No matching authentication protocol error in 12.1 Oracle ASM and Oracle Grid Infrastructure environments.

Workaround: Set SQLNET.ALLOWED_LOGON_VERSION=8 in the oracle/network/admin/sqlnet.ora file.

gnuplot plotting multiple line graphs

andyras is completely correct. One minor addition, try this (for example)

plot 'ls.dat' using 4:xtic(1)

This will keep your datafile in the correct order, but also preserve your version tic labels on the x-axis.

Bootstrap: Collapse other sections when one is expanded

The Method Works Properly For me:

var lanopt = $(".language-option");

lanopt.on("show.bs.collapse",".collapse", function(){
   lanopt.find(".collapse.in").collapse("hide");
});

How to measure time taken by a function to execute

It may help you.

var t0 = date.now(); doSomething(); var t1 = date.now(); console.log("Call to doSomething took approximate" + (t1 - t0)/1000 + " seconds.")

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known

Another reason this can sometimes come up is due to a misconfiguration in your docker-compose (if you're using it) whereby the mysql container is not on the same network that your app servers are on.

If the network flag is forgotten or incorrect docker won't add the mysql to the DNS for the app server and therefore throw an error like this.

How to get jSON response into variable from a jquery script

You should use data.response in your JS instead of json.response.

How to drop columns by name in a data frame

df2 <- df[!names(df) %in% c("c1", "c2")]

Understanding dispatch_async

The main reason you use the default queue over the main queue is to run tasks in the background.

For instance, if I am downloading a file from the internet and I want to update the user on the progress of the download, I will run the download in the priority default queue and update the UI in the main queue asynchronously.

dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void){
    //Background Thread
    dispatch_async(dispatch_get_main_queue(), ^(void){
        //Run UI Updates
    });
});

Copy tables from one database to another in SQL Server

  1. Script the create table in management studio, run that script in bar to create the table. (Right click table in object explorer, script table as, create to...)

  2. INSERT bar.[schema].table SELECT * FROM foo.[schema].table

How to gzip all files in all sub-directories into one compressed file in bash

there are lots of compression methods that work recursively command line and its good to know who the end audience is.

i.e. if it is to be sent to someone running windows then zip would probably be best:

zip -r file.zip folder_to_zip

unzip filenname.zip

for other linux users or your self tar is great

tar -cvzf filename.tar.gz folder

tar -cvjf filename.tar.bz2 folder  # even more compression

#change the -c to -x to above to extract

One must be careful with tar and how things are tarred up/extracted, for example if I run

cd ~
tar -cvzf passwd.tar.gz /etc/passwd
tar: Removing leading `/' from member names
/etc/passwd


pwd

/home/myusername

tar -xvzf passwd.tar.gz

this will create /home/myusername/etc/passwd

unsure if all versions of tar do this:

 Removing leading `/' from member names

How do I find the PublicKeyToken for a particular dll?

Answer is very simple use the .NET Framework tools sn.exe. So open the Visual Studio 2008 Command Prompt and then point to the dll’s folder you want to get the public key,

Use the following command,

sn –T myDLL.dll

This will give you the public key token. Remember one thing this only works if the assembly has to be strongly signed.

Example

C:\WINNT\Microsoft.NET\Framework\v3.5>sn -T EdmGen.exe

Microsoft (R) .NET Framework Strong Name Utility  Version 3.5.21022.8
Copyright (c) Microsoft Corporation.  All rights reserved.

Public key token is b77a5c561934e089

How to update nested state properties in React

i saw following in a book:

this.setState(state => state.someProperty.falg = false);

but i'm not sure if it's right..

Putting an if-elif-else statement on one line?

People have already mentioned ternary expressions. Sometimes with a simple conditional assignment as your example, it is possible to use a mathematical expression to perform the conditional assignment. This may not make your code very readable, but it does get it on one fairly short line. Your example could be written like this:

x = 2*(i>100) | 1*(i<100)

The comparisons would be True or False, and when multiplying with numbers would then be either 1 or 0. One could use a + instead of an | in the middle.

Oracle: SQL select date with timestamp

Answer provided by Nicholas Krasnov

SELECT *
FROM BOOKING_SESSION
WHERE TO_CHAR(T_SESSION_DATETIME, 'DD-MM-YYYY') ='20-03-2012';

Add a column to existing table and uniquely number them on MS SQL Server

And the Postgres equivalent (second line is mandatory only if you want "id" to be a key):

ALTER TABLE tableName ADD id SERIAL;
ALTER TABLE tableName ADD PRIMARY KEY (id);

How to use variables in a command in sed?

Say:

sed "s|\$ROOT|${HOME}|" abc.sh

Note:

  • Use double quotes so that the shell would expand variables.
  • Use a separator different than / since the replacement contains /
  • Escape the $ in the pattern since you don't want to expand it.

EDIT: In order to replace all occurrences of $ROOT, say

sed "s|\$ROOT|${HOME}|g" abc.sh

Disabled href tag

Letting a parent have pointer-events: none will disable the child a-tag like this (requires that the div covers the a and hasn't 0 width/height):

<div class="disabled">
   <a href="/"></a>
</div>

where:

.disabled {
    pointer-events: none;
}

You must enable the openssl extension to download files via https

I also had the same issue while playing around Zend Framework 2 and composer. I'm using PHP 5.4 (installed via macports) and my solution was to install openssl for PHP 5.4 via macports as well.

sudo port install php54-openssl

Entity Framework VS LINQ to SQL VS ADO.NET with stored procedures?

your question is basically O/RM's vs hand writing SQL

Using an ORM or plain SQL?

Take a look at some of the other O/RM solutions out there, L2S isn't the only one (NHibernate, ActiveRecord)

http://en.wikipedia.org/wiki/List_of_object-relational_mapping_software

to address the specific questions:

  1. Depends on the quality of the O/RM solution, L2S is pretty good at generating SQL
  2. This is normally much faster using an O/RM once you grok the process
  3. Code is also usually much neater and more maintainable
  4. Straight SQL will of course get you more flexibility, but most O/RM's can do all but the most complicated queries
  5. Overall I would suggest going with an O/RM, the flexibility loss is negligable