How to add LocalDB to Visual Studio 2015 Community's SQL Server Object Explorer?
My App.config looks as below:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v11.0" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
</providers>
</entityFramework>
</configuration>
I noticed that there is localDB in the path that you mentioned above and has the version v11.0.
So I entered (LocalDB\V11.0) in Add Connection dialogue and it worked for me.
The network path was not found
Same problem with me. I solved this by adding @
before connection string (C# has a thing called 'String Literals') like so:
SqlConnection sconnection = new SqlConnection(@"Data Source=(Localdb)\v11.0; Initial Catalog=Mydatabase;Integrated Security=True");
sconnection.Open();
Use C# HttpWebRequest to send json to web service
First of all you missed ScriptService attribute to add in webservice.
[ScriptService]
After then try following method to call webservice via JSON.
var webAddr = "http://Domain/VBRService.asmx/callJson";
var httpWebRequest = (HttpWebRequest)WebRequest.Create(webAddr);
httpWebRequest.ContentType = "application/json; charset=utf-8";
httpWebRequest.Method = "POST";
using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = "{\"x\":\"true\"}";
streamWriter.Write(json);
streamWriter.Flush();
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
var result = streamReader.ReadToEnd();
return result;
}
EntityType has no key defined error
You don't have to use key attribute all the time. Make sure the mapping file properly addressed the key
this.HasKey(t => t.Key);
this.ToTable("PacketHistory");
this.Property(p => p.Key)
.HasColumnName("PacketHistorySK");
and don't forget to add the mapping in the Repository's OnModelCreating
modelBuilder.Configurations.Add(new PacketHistoryMap());
"Use the new keyword if hiding was intended" warning
@wdavo is correct. The same is also true for functions.
If you override a base function, like Update, then in your subclass you need:
new void Update()
{
//do stufff
}
Without the new at the start of the function decleration you will get the warning flag.
"Input string was not in a correct format."
I ran into this exact exception, except it had nothing to do with parsing numerical inputs. So this isn't an answer to the OP's question, but I think it's acceptable to share the knowledge.
I'd declared a string and was formatting it for use with JQTree which requires curly braces ({}). You have to use doubled curly braces for it to be accepted as a properly formatted string:
string measurements = string.empty;
measurements += string.Format(@"
{{label: 'Measurement Name: {0}',
children: [
{{label: 'Measured Value: {1}'}},
{{label: 'Min: {2}'}},
{{label: 'Max: {3}'}},
{{label: 'Measured String: {4}'}},
{{label: 'Expected String: {5}'}},
]
}},",
drv["MeasurementName"] == null ? "NULL" : drv["MeasurementName"],
drv["MeasuredValue"] == null ? "NULL" : drv["MeasuredValue"],
drv["Min"] == null ? "NULL" : drv["Min"],
drv["Max"] == null ? "NULL" : drv["Max"],
drv["MeasuredString"] == null ? "NULL" : drv["MeasuredString"],
drv["ExpectedString"] == null ? "NULL" : drv["ExpectedString"]);
Hopefully this will help other folks who find this question but aren't parsing numerical data.
How to change column width in DataGridView?
You could set the width of the abbrev column to a fixed pixel width, then set the width of the description column to the width of the DataGridView, minus the sum of the widths of the other columns and some extra margin (if you want to prevent a horizontal scrollbar from appearing on the DataGridView):
dataGridView1.Columns[1].Width = 108; // or whatever width works well for abbrev
dataGridView1.Columns[2].Width =
dataGridView1.Width
- dataGridView1.Columns[0].Width
- dataGridView1.Columns[1].Width
- 72; // this is an extra "margin" number of pixels
If you wanted the description column to always take up the "remainder" of the width of the DataGridView, you could put something like the above code in a Resize
event handler of the DataGridView.
Chart creating dynamically. in .net, c#
You need to attach the Form1_Load
handler to the Load
event:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;
using System.Diagnostics;
namespace WindowsFormsApplication6
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
Load += Form1_Load;
}
private void Form1_Load(object sender, EventArgs e)
{
Random rnd = new Random();
Chart mych = new Chart();
mych.Height = 100;
mych.Width = 100;
mych.BackColor = SystemColors.Highlight;
mych.Series.Add("duck");
mych.Series["duck"].SetDefault(true);
mych.Series["duck"].Enabled = true;
mych.Visible = true;
for (int q = 0; q < 10; q++)
{
int first = rnd.Next(0, 10);
int second = rnd.Next(0, 10);
mych.Series["duck"].Points.AddXY(first, second);
Debug.WriteLine(first + " " + second);
}
Controls.Add(mych);
}
}
}
How to add dll in c# project
Have you added the dll into your project references list?
If not right click on the project "References" folder and selecet "Add Reference" then use browse to locate your science.dll, select it and click ok.
edit
I can't see the image of your VS instance that some people are referring to and I note that you now say that it works in Net4.0 and VS2010.
VS2008 projects support NET 3.5 by default. I expect that is the problem as your DLL may be NET 4.0 compliant but not NET 3.5.
The type or namespace name 'DbContext' could not be found
Like the others have suggested:
- Add the correct references and directives. But it still doesn't work? Maybe you have the same problem I did:
Have a look below and see if you can tell me what is wrong:
public class PanelLengthContext : DBContext { }
??!
Make sure the class name is not misspelt - (case sensitivity)!
DbContext
is the correct spelling.
- this is how it should look:
- check the spelling. don't waste 20 min of your life like i did.
public class PanelLengthContext : DbContext {}
HTH
Int or Number DataType for DataAnnotation validation attribute
ASP.NET Core 3.1
This is my implementation of the feature, it works on server side as well as with jquery validation unobtrusive with a custom error message just like any other attribute:
The attribute:
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
public class MustBeIntegerAttribute : ValidationAttribute, IClientModelValidator
{
public void AddValidation(ClientModelValidationContext context)
{
MergeAttribute(context.Attributes, "data-val", "true");
var errorMsg = FormatErrorMessage(context.ModelMetadata.GetDisplayName());
MergeAttribute(context.Attributes, "data-val-mustbeinteger", errorMsg);
}
public override bool IsValid(object value)
{
return int.TryParse(value?.ToString() ?? "", out int newVal);
}
private bool MergeAttribute(
IDictionary<string, string> attributes,
string key,
string value)
{
if (attributes.ContainsKey(key))
{
return false;
}
attributes.Add(key, value);
return true;
}
}
Client side logic:
$.validator.addMethod("mustbeinteger",
function (value, element, parameters) {
return !isNaN(parseInt(value)) && isFinite(value);
});
$.validator.unobtrusive.adapters.add("mustbeinteger", [], function (options) {
options.rules.mustbeinteger = {};
options.messages["mustbeinteger"] = options.message;
});
And finally the Usage:
[MustBeInteger(ErrorMessage = "You must provide a valid number")]
public int SomeNumber { get; set; }
The type initializer for 'MyClass' threw an exception
The type initializer for 'CSMessageUtility.CSDetails' threw an exception.
means that the static constructor on that class threw an Exception - so you need to look either in the static constructor of the CSDetails class, or in the initialisation of any static members of that class.
Serialize an object to XML
I have a simple way to serialize an object to XML using C#, it works great and it's highly reusable. I know this is an older thread, but I wanted to post this because someone may find this helpful to them.
Here is how I call the method:
var objectToSerialize = new MyObject();
var xmlString = objectToSerialize.ToXmlString();
Here is the class that does the work:
Note: Since these are extension methods they need to be in a static class.
using System.IO;
using System.Xml.Serialization;
public static class XmlTools
{
public static string ToXmlString<T>(this T input)
{
using (var writer = new StringWriter())
{
input.ToXml(writer);
return writer.ToString();
}
}
private static void ToXml<T>(this T objectToSerialize, StringWriter writer)
{
new XmlSerializer(typeof(T)).Serialize(writer, objectToSerialize);
}
}
The type or namespace cannot be found (are you missing a using directive or an assembly reference?)
You don't have the namespace the Login class is in as a reference.
Add the following to the form that uses the Login
class:
using FootballLeagueSystem;
When you want to use a class in another namespace, you have to tell the compiler where to find it. In this case, Login
is inside the FootballLeagueSystem
namespace, or : FootballLeagueSystem.Login
is the fully qualified namespace.
As a commenter pointed out, you declare the Login class inside the FootballLeagueSystem
namespace, but you're using it in the FootballLeague
namespace.
How can I bind a background color in WPF/XAML?
You assigned a string "Red". Your Background property should be of type Color:
using System.Windows;
using System.ComponentModel;
namespace TestBackground88238
{
public partial class Window1 : Window, INotifyPropertyChanged
{
#region ViewModelProperty: Background
private Color _background;
public Color Background
{
get
{
return _background;
}
set
{
_background = value;
OnPropertyChanged("Background");
}
}
#endregion
//...//
}
Then you can use the binding to the SolidColorBrush like this:
public Window1()
{
InitializeComponent();
DataContext = this;
Background = Colors.Red;
Message = "This is the title, the background should be " + Background.toString() + ".";
}
not 100% sure about the .toString() method on Color-Object. It might tell you it is a Color-Class, but you will figur this out ;)
Getting attributes of Enum's value
In addition to AdamCrawford response, I've further created a more specialized extension methods that feed of it to get the description.
public static string GetAttributeDescription(this Enum enumValue)
{
var attribute = enumValue.GetAttributeOfType<DescriptionAttribute>();
return attribute == null ? String.Empty : attribute.Description;
}
hence, to get the description, you could either use the original extension method as
string desc = myEnumVariable.GetAttributeOfType<DescriptionAttribute>().Description
or you could simply call the the extension method here as:
string desc = myEnumVariable.GetAttributeDescription();
Which should hopefully make your code a bit more readable.
Using PropertyInfo.GetValue()
In your example propertyInfo.GetValue(this, null)
should work. Consider altering GetNamesAndTypesAndValues()
as follows:
public void GetNamesAndTypesAndValues()
{
foreach (PropertyInfo propertyInfo in allClassProperties)
{
Console.WriteLine("{0} [type = {1}] [value = {2}]",
propertyInfo.Name,
propertyInfo.PropertyType,
propertyInfo.GetValue(this, null));
}
}
Setting the default value of a DateTime Property to DateTime.Now inside the System.ComponentModel Default Value Attrbute
I think you can do this using StoreGeneratedPattern = Identity
(set in the model designer properties window).
I wouldn't have guessed that would be how to do it, but while trying to figure it out I noticed that some of my date columns were already defaulting to CURRENT_TIMESTAMP()
and some weren't. Checking the model, I see that the only difference between the two columns besides the name is that the one getting the default value has StoreGeneratedPattern
set to Identity
.
I wouldn't have expected that to be the way, but reading the description, it sort of makes sense:
Determines if the corresponding column in the database will be auto-generated during insert and update operations.
Also, while this does make the database column have a default value of "now", I guess it does not actually set the property to be DateTime.Now
in the POCO. This hasn't been an issue for me as I have a customized .tt file that already sets all of my date columns to DateTime.Now
automatically (it's actually not hard to modify the .tt file yourself, especially if you have ReSharper and get a syntax highlighting plugin. (Newer versions of VS may already syntax highlight .tt files, not sure.))
The issue for me was: how do I get the database column to have a default so that existing queries that omit that column will still work? And the above setting worked for that.
I haven't tested it yet but it's also possible that setting this will interfere with setting your own explicit value. (I only stumbled upon this in the first place because EF6 Database First wrote the model for me this way.)
Creating a constant Dictionary in C#
This is the closest thing you can get to a "CONST Dictionary":
public static int GetValueByName(string name)
{
switch (name)
{
case "bob": return 1;
case "billy": return 2;
default: return -1;
}
}
The compiler will be smart enough to build the code as clean as possible.
Winforms issue - Error creating window handle
Have you run Process Explorer or the Windows Task Manager to look at the GDI Objects, Handles, Threads and USER objects? If not, select those columns to be viewed (Task Manager choose View->Select Columns... Then run your app and take a look at those columns for that app and see if one of those is growing really large.
It might be that you've got UI components that you think are cleaned up but haven't been Disposed.
Here's a link about this that might be helpful.
Good Luck!
Hidden Features of C#?
Convert enum values to a string value
Given the enum
enum Country
{
UnitedKingdom,
UnitedStates,
UnitedArabEmirates,
}
using it:
public static void PrintEnumAsString( Country country )
{
Console.Writeline( country.ToString() );
}
will print the name of the enum value as a string, e.g. "UnitedKingdom"
Losing Session State
In my case setting AppPool->AdvancedSettings->Maximum Worker Proccesses to 1 helped.
How to return history of validation loss in Keras
I have also found that you can use verbose=2
to make keras print out the Losses:
history = model.fit(X, Y, validation_split=0.33, nb_epoch=150, batch_size=10, verbose=2)
And that would print nice lines like this:
Epoch 1/1
- 5s - loss: 0.6046 - acc: 0.9999 - val_loss: 0.4403 - val_acc: 0.9999
According to their documentation:
verbose: 0, 1, or 2. Verbosity mode. 0 = silent, 1 = progress bar, 2 = one line per epoch.
App installation failed due to application-identifier entitlement
My problem was the App ID in combination with the certificate used to create the provisioning profiles. None of my provisioning profiles were working because none of them were "Elgible" (created with a certificate that matched the App ID). I had moved development to a new machine, so perhaps this was the deeper reason. At any rate I had to create a new certificate, then new provisioning profiles with that certificate being careful to choose the right App ID when creating them. Good luck.
Batch Extract path and filename from a variable
if you want infos from the actual running batchfile,
try this :
@echo off
set myNameFull=%0
echo myNameFull %myNameFull%
set myNameShort=%~n0
echo myNameShort %myNameShort%
set myNameLong=%~nx0
echo myNameLong %myNameLong%
set myPath=%~dp0
echo myPath %myPath%
set myLogfileWpath=%myPath%%myNameShort%.log
echo myLogfileWpath %myLogfileWpath%
more samples?
C:> HELP CALL
%0 = parameter 0 = batchfile
%1 = parameter 1 - 1st par. passed to batchfile... so you can try that stuff (e.g. "~dp") between 1st (e.g. "%") and last (e.g. "1") also for parameters
Split array into two parts without for loop in java
You can use System.arraycopy()
.
int[] source = new int[1000];
int[] part1 = new int[500];
int[] part2 = new int[500];
// (src , src-offset , dest , offset, count)
System.arraycopy(source, 0 , part1, 0 , part1.length);
System.arraycopy(source, part1.length, part2, 0 , part2.length);
How to disable input conditionally in vue.js
To toggle the input's disabled attribute was surprisingly complex. The issue for me was twofold:
(1) Remember: the input's "disabled" attribute is NOT a Boolean attribute.
The mere presence of the attribute means that the input is disabled.
However, the Vue.js creators have prepared this...
https://vuejs.org/v2/guide/syntax.html#Attributes
(Thanks to @connexo for this... How to add disabled attribute in input text in vuejs?)
(2) In addition, there was a DOM timing re-rendering issue that I was having. The DOM was not updating when I tried to toggle back.
Upon certain situations, "the component will not re-render immediately. It will update in the next 'tick.'"
From Vue.js docs: https://vuejs.org/v2/guide/reactivity.html
The solution was to use:
this.$nextTick(()=>{
this.disableInputBool = true
})
Fuller example workflow:
<div @click="allowInputOverwrite">
<input
type="text"
:disabled="disableInputBool">
</div>
<button @click="disallowInputOverwrite">
press me (do stuff in method, then disable input bool again)
</button>
<script>
export default {
data() {
return {
disableInputBool: true
}
},
methods: {
allowInputOverwrite(){
this.disableInputBool = false
},
disallowInputOverwrite(){
// accomplish other stuff here.
this.$nextTick(()=>{
this.disableInputBool = true
})
}
}
}
</script>
Excel: macro to export worksheet as CSV file without leaving my current Excel sheet
For those situations where you need a bit more customisation of the output (separator or decimal symbol), or who have large dataset (over 65k rows), I wrote the following:
Option Explicit
Sub rng2csv(rng As Range, fileName As String, Optional sep As String = ";", Optional decimalSign As String)
'export range data to a CSV file, allowing to chose the separator and decimal symbol
'can export using rng number formatting!
'by Patrick Honorez --- www.idevlop.com
Dim f As Integer, i As Long, c As Long, r
Dim ar, rowAr, sOut As String
Dim replaceDecimal As Boolean, oldDec As String
Dim a As Application: Set a = Application
ar = rng
f = FreeFile()
Open fileName For Output As #f
oldDec = Format(0, ".") 'current client's decimal symbol
replaceDecimal = (decimalSign <> "") And (decimalSign <> oldDec)
For Each r In rng.Rows
rowAr = a.Transpose(a.Transpose(r.Value))
If replaceDecimal Then
For c = 1 To UBound(rowAr)
'use isnumber() to avoid cells with numbers formatted as strings
If a.IsNumber(rowAr(c)) Then
'uncomment the next 3 lines to export numbers using source number formatting
' If r.cells(1, c).NumberFormat <> "General" Then
' rowAr(c) = Format$(rowAr(c), r.cells(1, c).NumberFormat)
' End If
rowAr(c) = Replace(rowAr(c), oldDec, decimalSign, 1, 1)
End If
Next c
End If
sOut = Join(rowAr, sep)
Print #f, sOut
Next r
Close #f
End Sub
Sub export()
Debug.Print Now, "Start export"
rng2csv shOutput.Range("a1").CurrentRegion, RemoveExt(ThisWorkbook.FullName) & ".csv", ";", "."
Debug.Print Now, "Export done"
End Sub
Styling HTML email for Gmail
Note that services and tools for sending emails may be able to inline your CSS for you, allowing CSS in <style>
tags to work in Gmail.
For instance, if you're sending emails with MailChimp, your CSS from <style>
tags will get inlined automatically by default. With Mandrill, you can enable this functionality (although it's disabled by default for performance reasons) by checking the "Inline CSS Styles in HTML Emails" box in the "Sending Defaults" section of the Settings tab:
Convert a String of Hex into ASCII in Java
So as I understand it, you need to pull out successive pairs of hex digits, then decode that 2-digit hex number and take the corresponding char:
String s = "...";
StringBuilder sb = new StringBuilder(s.length() / 2);
for (int i = 0; i < s.length(); i+=2) {
String hex = "" + s.charAt(i) + s.charAt(i+1);
int ival = Integer.parseInt(hex, 16);
sb.append((char) ival);
}
String string = sb.toString();
With CSS, use "..." for overflowed block of multi-lines
Bit late to this party but I came up with, what I think, is a unique solution. Rather than trying to insert your own ellipsis through css trickery or js I thought i'd try and roll with the single line only restriction. So I duplicate the text for every "line" and just use a negative text-indent to make sure one line starts where the last one stops. FIDDLE
CSS:
#wrapper{
font-size: 20pt;
line-height: 22pt;
width: 100%;
overflow: hidden;
padding: 0;
margin: 0;
}
.text-block-line{
height: 22pt;
display: inline-block;
max-width: 100%;
overflow: hidden;
white-space: nowrap;
width: auto;
}
.text-block-line:last-child{
text-overflow: ellipsis;
}
/*the follwing is suboptimal but neccesary I think. I'd probably just make a sass mixin that I can feed a max number of lines to and have them avialable. Number of lines will need to be controlled by server or client template which is no worse than doing a character count clip server side now. */
.line2{
text-indent: -100%;
}
.line3{
text-indent: -200%;
}
.line4{
text-indent: -300%;
}
HTML:
<p id="wrapper" class="redraw">
<span class="text-block-line line1">This text is repeated for every line that you want to be displayed in your element. This example has a max of 4 lines before the ellipsis occurs. Try scaling the preview window width to see the effect.</span>
<span class="text-block-line line2">This text is repeated for every line that you want to be displayed in your element. This example has a max of 4 lines before the ellipsis occurs. Try scaling the preview window width to see the effect.</span>
<span class="text-block-line line3">This text is repeated for every line that you want to be displayed in your element. This example has a max of 4 lines before the ellipsis occurs. Try scaling the preview window width to see the effect.</span>
<span class="text-block-line line4">This text is repeated for every line that you want to be displayed in your element. This example has a max of 4 lines before the ellipsis occurs. Try scaling the preview window width to see the effect.</span>
</p>
More details in the fiddle. There is an issue with the browser reflowing that I use a JS redraw for and such so do check it out but this is the basic concept. Any thoughts/suggestions are much appreciated.
How to downgrade from Internet Explorer 11 to Internet Explorer 10?
- Save and close all Internet Explorer windows and then, run Windows Task Manager to end the running processes in background.
- Go to Control Panel.
- Click Programs and choose the View installed updates instead.
- Locate the following Windows Internet Explorer 11 or you can type "Internet Explorer" for a quick search.
- Choose the Yes option from the following "Uninstall an update".
- Please wait while Windows Internet Explorer 10 is being restored and reconfigured automatically.
- Follow the Microsoft Windows wizard to restart your system.
Note: You can do it for as many earlier versions you want, i.e. IE9, IE8 and so on.
Java: how to initialize String[]?
String Declaration:
String str;
String Initialization
String[] str=new String[3];//if we give string[2] will get Exception insted
str[0]="Tej";
str[1]="Good";
str[2]="Girl";
String str="SSN";
We can get individual character in String:
char chr=str.charAt(0);`//output will be S`
If I want to to get individual character Ascii value like this:
System.out.println((int)chr); //output:83
Now i want to convert Ascii value into Charecter/Symbol.
int n=(int)chr;
System.out.println((char)n);//output:S
Calculate RSA key fingerprint
To see your key on Ubuntu, just enter the following command on your terminal:
ssh-add -l
You will get an output like this:
2568 0j:20:4b:88:a7:9t:wd:19:f0:d4:4y:9g:27:cf:97:23
yourName@ubuntu (RSA)
If however you get an error like; Could not open a connection to your authentication agent.
Then it means that ssh-agent is not running. You can start/run it with:
ssh-agent bash
(thanks to @Richard in the comments) and then re-run ssh-add -l
Find JavaScript function definition in Chrome
This landed in Chrome on 2012-08-26
Not sure about the exact version, I noticed it in Chrome 24.
A screenshot is worth a million words:
I am inspecting an object with methods in the Console. Clicking on the "Show function definition" takes me to the place in the source code where the function is defined. Or I can just hover over the function () {
word to see function body in a tooltip. You can easily inspect the whole prototype chain like this! CDT definitely rock!!!
Hope you all find it helpful!
how to create 100% vertical line in css
I use this css positioning for most of my vertical elements:
<div class="vertical-line" style="height: 250px;
width: 1px;
background-color: #81F781;
margin-left: 0px;
margin-top: -100px;
postion: absolute;
border-radius: 2px;">
</div>
Change the height and width to fit the page, or to make a horizontal line swap the height to width:
<div class="vertical-line" style="height: 250px;
width: 1px;
<div class="vertical-line" style="width: 250px;
height: 1px;
instead of a standard html line.
How to view user privileges using windows cmd?
Go to command prompt and enter the command,
net user <username>
Will show your local group memberships.
If you're on a domain, use localgroup instead:
net localgroup Administrators or net localgroup [Admin group name]
Check the list of local groups with localgroup on its own.
net localgroup
What is the documents directory (NSDocumentDirectory)?
You can access documents directory using this code it is basically used for storing file in plist format:
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths firstObject];
return documentsDirectory;
Run Executable from Powershell script with parameters
Here is an alternative method for doing multiple args. I use it when the arguments are too long for a one liner.
$app = 'C:\Program Files\MSBuild\test.exe'
$arg1 = '/genmsi'
$arg2 = '/f'
$arg3 = '$MySourceDirectory\src\Deployment\Installations.xml'
& $app $arg1 $arg2 $arg3
What do curly braces mean in Verilog?
As Matt said, the curly braces are for concatenation. The extra curly braces around 16{a[15]}
are the replication operator. They are described in the IEEE Standard for Verilog document (Std 1364-2005), section "5.1.14 Concatenations".
{16{a[15]}}
is the same as
{
a[15], a[15], a[15], a[15], a[15], a[15], a[15], a[15],
a[15], a[15], a[15], a[15], a[15], a[15], a[15], a[15]
}
In bit-blasted form,
assign result = {{16{a[15]}}, {a[15:0]}};
is the same as:
assign result[ 0] = a[ 0];
assign result[ 1] = a[ 1];
assign result[ 2] = a[ 2];
assign result[ 3] = a[ 3];
assign result[ 4] = a[ 4];
assign result[ 5] = a[ 5];
assign result[ 6] = a[ 6];
assign result[ 7] = a[ 7];
assign result[ 8] = a[ 8];
assign result[ 9] = a[ 9];
assign result[10] = a[10];
assign result[11] = a[11];
assign result[12] = a[12];
assign result[13] = a[13];
assign result[14] = a[14];
assign result[15] = a[15];
assign result[16] = a[15];
assign result[17] = a[15];
assign result[18] = a[15];
assign result[19] = a[15];
assign result[20] = a[15];
assign result[21] = a[15];
assign result[22] = a[15];
assign result[23] = a[15];
assign result[24] = a[15];
assign result[25] = a[15];
assign result[26] = a[15];
assign result[27] = a[15];
assign result[28] = a[15];
assign result[29] = a[15];
assign result[30] = a[15];
assign result[31] = a[15];
How different is Scrum practice from Agile Practice?
As mentioned Agile is a set of principles about how a methodology should be implemented to achieve the benefits of embracing change, close co-operation etc. These principles address some of the project management issues found in studies such as the Chaos Report by the Standish group.
Agile methodologies are created by the development and supporting teams to meet the principles. The methodology is made to fit the business and changed as appropriate.
SCRUM is a fixed set of processes to implement an incremental development methodology. Since the processes are fixed and not catered to the teams it cannot really be considered agile in the original sense of focus on individuals rather than processes.
How to add an ORDER BY clause using CodeIgniter's Active Record methods?
function getProductionGroupItems($itemId){
$this->db->select("*");
$this->db->where("id",$itemId);
$this->db->or_where("parent_item_id",$itemId);
/*********** order by *********** */
$this->db->order_by("id", "asc");
$q=$this->db->get("recipe_products");
if($q->num_rows()>0){
foreach($q->result() as $row){
$data[]=$row;
}
return $data;
}
return false;
}
Typescript: No index signature with a parameter of type 'string' was found on type '{ "A": string; }
Don't Use Any, Use Generics
// bad
const _getKeyValue = (key: string) => (obj: object) => obj[key];
// better
const _getKeyValue_ = (key: string) => (obj: Record<string, any>) => obj[key];
// best
const getKeyValue = <T extends object, U extends keyof T>(key: U) => (obj: T) =>
obj[key];
Bad - the reason for the error is the object
type is just an empty object by default. Therefore it isn't possible to use a string
type to index {}
.
Better - the reason the error disappears is because now we are telling the compiler the obj
argument will be a collection of string/value (string/any
) pairs. However, we are using the any
type, so we can do better.
Best - T
extends empty object. U
extends the keys of T
. Therefore U
will always exist on T
, therefore it can be used as a look up value.
Here is a full example:
I have switched the order of the generics (U extends keyof T
now comes before T extends object
) to highlight that order of generics is not important and you should select an order that makes the most sense for your function.
const getKeyValue = <U extends keyof T, T extends object>(key: U) => (obj: T) =>
obj[key];
interface User {
name: string;
age: number;
}
const user: User = {
name: "John Smith",
age: 20
};
const getUserName = getKeyValue<keyof User, User>("name")(user);
// => 'John Smith'
Alternative syntax
const getKeyValue = <T, K extends keyof T>(obj: T, key: K): T[K] => obj[key];
Javascript : array.length returns undefined
It looks as though it's not an array but an arbitrary object. If you have control over the PHP serialization, you might be able to change that.
As raina77ow pointed out, one way to do this in PHP would be by replacing something like this:
json_encode($something)
with something like:
json_encode(array_values($something))
But don't ignore the other answers here about Object.keys
. They should also accomplish what you want if you don't have the ability or the desire to change the serialization of your object.
Should CSS always preceed Javascript?
Here is a SUMMARY of all the major answers above (or maybe below later :)
For modern browsers, put css wherever you like it. They would analyze your html file (which they call speculative parsing) and start downloading css in parallel with html parsing.
For old browsers keep putting css on top (if you don't want to show a naked but interactive page first).
For all browsers, put javascript as farther down on the page as possible, since it will halt parsing of your html. Preferably, download it asynchronously (i.e., ajax call)
There are also, some experimental results for a particular case which claims putting javascript first (as opposed to traditional wisdom of putting CSS first) gives better performance but there is no logical reasoning given for it, and lacks validation regarding widespread applicability, so you can ignore it for now.
So, to answer the question: Yes. The recommendation to include the CSS before JS is invalid for the modern browsers. Put CSS wherever you like, and put JS towards the end, as possible.
What is the difference between `throw new Error` and `throw someObject`?
TLDR: they are equivalent Error(x) === new Error(x)
.
// this:
const x = Error('I was created using a function call!');
????// has the same functionality as this:
const y = new Error('I was constructed via the "new" keyword!');
source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error
throw and throw Error will are functionally equivalent. But when you catch them and serialize them to console.log they are not serialized exactly the same way:
throw 'Parameter is not a number!';
throw new Error('Parameter is not a number!');
throw Error('Parameter is not a number!');
Console.log(e) of the above will produce 2 different results:
Parameter is not a number!
Error: Parameter is not a number!
Error: Parameter is not a number!
How to get local server host and port in Spring Boot?
IP Address
You can get network interfaces with NetworkInterface.getNetworkInterfaces()
, then the IP addresses off the NetworkInterface objects returned with .getInetAddresses()
, then the string representation of those addresses with .getHostAddress()
.
Port
If you make a @Configuration
class which implements ApplicationListener<EmbeddedServletContainerInitializedEvent>
, you can override onApplicationEvent
to get the port number once it's set.
@Override
public void onApplicationEvent(EmbeddedServletContainerInitializedEvent event) {
int port = event.getEmbeddedServletContainer().getPort();
}
Javascript form validation with password confirming
Just add onsubmit
event handler for your form:
<form action="insert.php" onsubmit="return myFunction()" method="post">
Remove onclick
from button
and make it input
with type submit
<input type="submit" value="Submit">
And add boolean return statements to your function:
function myFunction() {
var pass1 = document.getElementById("pass1").value;
var pass2 = document.getElementById("pass2").value;
var ok = true;
if (pass1 != pass2) {
//alert("Passwords Do not match");
document.getElementById("pass1").style.borderColor = "#E34234";
document.getElementById("pass2").style.borderColor = "#E34234";
return false;
}
else {
alert("Passwords Match!!!");
}
return ok;
}
Change div height on button click
Just a silly mistake use quote('') in '200px'
<html>
<head>
</head>
<body >
<button type="button" onClick = "document.getElementById('chartdiv').style.height = '200px';">Click Me!</button>
<div id="chartdiv" style="width: 100%; height: 50px; background-color:#E8EDF2"></div>
</body>
Circle-Rectangle collision detection (intersection)
- do a pre-check whether a circle fully encapsulating the rectangle collides with the circle.
- check for rectangle corners within the circle.
- For each edge, see if there is a line intersection with the circle. Project the center point C onto the line AB to get a point D. If the length of CD is less than radius, there was a collision.
projectionScalar=dot(AC,AB)/(mag(AC)*mag(AB));
if(projectionScalar>=0 && projectionScalar<=1) {
D=A+AB*projectionScalar;
CD=D-C;
if(mag(CD)<circle.radius){
// there was a collision
}
}
How to filter JSON Data in JavaScript or jQuery?
You can use jQuery each function as it is explained below:
Define your data:
var jsonStr = '[{"name":"Lenovo Thinkpad 41A4298,"website":"google"},{"name":"Lenovo Thinkpad 41A2222,"website":"google"},{"name":"Lenovo Thinkpad 41Awww33,"website":"yahoo"},{"name":"Lenovo Thinkpad 41A424448,"website":"google"},{"name":"Lenovo Thinkpad 41A429rr8,"website":"ebay"},{"name":"Lenovo Thinkpad 41A429ff8,"website":"ebay"},{"name":"Lenovo Thinkpad 41A429ss8,"website":"rediff"},{"name":"Lenovo Thinkpad 41A429sg8,"website":"yahoo"}]';
Parse JSON string to JSON object:
var json = JSON.parse(jsonStr);
Iterate and filter:
$.each(JSON.parse(json), function (idx, obj) {
if (obj.website == 'yahoo') {
// do whatever you want
}
});
Get form data in ReactJS
No need to use refs, you can access using event
function handleSubmit(e) {
e.preventDefault()
const {username, password } = e.target.elements
console.log({username: username.value, password: password.value })
}
<form onSubmit={handleSubmit}>
<input type="text" id="username"/>
<input type="text" id="password"/>
<input type="submit" value="Login" />
</form>
TypeError: ObjectId('') is not JSON serializable
SOLUTION for: mongoengine + marshmallow
If you use mongoengine
and marshamallow
then this solution might be applicable for you.
Basically, I imported String
field from marshmallow, and I overwritten default Schema id
to be String
encoded.
from marshmallow import Schema
from marshmallow.fields import String
class FrontendUserSchema(Schema):
id = String()
class Meta:
fields = ("id", "email")
How to use an array list in Java?
A three line solution, but works quite well:
int[] source_array = {0,1,2,3,4,5,6,7,8,9,10,11};
ArrayList<Integer> target_list = new ArrayList<Integer>();
for(int i = 0; i < source_array.length; i++){
target_list.add(random_array[i]);
}
How to convert a single char into an int
If you are worried about encoding, you can always use a switch statement.
Just be careful with the format you keep those large numbers in. The maximum size for an integer in some systems is as low as 65,535 (32,767 signed). Other systems, you've got 2,147,483,647 (or 4,294,967,295 unsigned)
Reading a single char in Java
Here is a class 'getJ' with a static function 'chr()'. This function reads one char.
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;
class getJ {
static char chr()throws IOException{
BufferedReader bufferReader =new BufferedReader(new InputStreamReader(System.in));
return bufferReader.readLine().charAt(0);
}
}
In order to read a char use this:
anyFunc()throws IOException{
...
...
char c=getJ.chr();
}
Because of 'chr()' is static, you don't have to create 'getJ' by 'new' ; I mean
you don't need to do:
getJ ob = new getJ;
c=ob.chr();
You should remember to add 'throws IOException' to the function's head. If it's impossible, use try / catch as follows:
anyFunc(){// if it's impossible to add 'throws IOException' here
...
try
{
char c=getJ.chr(); //reads a char into c
}
catch(IOException e)
{
System.out.println("IOException has been caught");
}
Credit to:
tutorialspoint.com
See also: geeksforgeeks.
java bufferedreader input getchar char
Responsive css styles on mobile devices ONLY
Why not use a media query range.
I'm currently working on a responsive layout for my employer and the ranges I'm using are as follows:
You have your main desktop styles in the body of the CSS file (1024px and above) and then for specific screen sizes I'm using:
@media all and (min-width:960px) and (max-width: 1024px) {
/* put your css styles in here */
}
@media all and (min-width:801px) and (max-width: 959px) {
/* put your css styles in here */
}
@media all and (min-width:769px) and (max-width: 800px) {
/* put your css styles in here */
}
@media all and (min-width:569px) and (max-width: 768px) {
/* put your css styles in here */
}
@media all and (min-width:481px) and (max-width: 568px) {
/* put your css styles in here */
}
@media all and (min-width:321px) and (max-width: 480px) {
/* put your css styles in here */
}
@media all and (min-width:0px) and (max-width: 320px) {
/* put your css styles in here */
}
This will cover pretty much all devices being used - I would concentrate on getting the styling correct for the sizes at the end of the range (i.e. 320, 480, 568, 768, 800, 1024) as for all the others they will just be responsive to the size available.
Also, don't use px anywhere - use em's or %.
A project with an Output Type of Class Library cannot be started directly
.Exe
's and .dll
's are both assemblies. The key difference is that executeables define an entry point Main
which can be invoked by the runtime. The error
"Class library cannot be started directly"
is due to the fact that said .dll
's do not have a Main
. To fix this issue, change the project type to a Windows application/Console application and define an entry point. Or, add a new project that is of type Windows application/Console application and reference said .dll
.
How to use not contains() in xpath?
You can use not(expression)
function
not()
is a function in xpath (as opposed to an operator)
Example:
//a[not(contains(@id, 'xx'))]
OR
expression != true()
Android statusbar icons color
Not since Lollipop. Starting with Android 5.0, the guidelines say:
Notification icons must be entirely white.
Even if they're not, the system will only consider the alpha channel of your icon, rendering them white
Workaround
The only way to have a coloured icon on Lollipop is to lower your targetSdkVersion
to values <21
, but I think you would do better to follow the guidelines and use white icons only.
If you still however decide you want colored icons, you could use the DrawableCompat.setTint method from the new v4 support library.
How to sort by Date with DataTables jquery plugin?
You should make use of the HTML5 Data Attributes.
https://www.datatables.net/examples/advanced_init/html5-data-attributes.html
Just add the data-order element to your td element.
No plugins required.
<table class="table" id="exampleTable">
<thead>
<tr>
<th>Firstname</th>
<th>Sign Up Date</th>
</tr>
</thead>
<tbody>
<tr>
<td>Peter</td>
<td data-order="2015-11-13 12:00">13. November 2015</td>
</tr>
<tr>
<td>Daniel</td>
<td data-order="2015-08-06 13:44">06. August 2015</td>
</tr>
<tr>
<td>Michael</td>
<td data-order="2015-10-14 16:12">14. October 2015</td>
</tr>
</tbody>
</table>
<script>
$(document).ready(function() {
$('#exampleTable').DataTable();
});
</script>
how to split the ng-repeat data with three columns using bootstrap
I found myself in a similar case, wanting to generate display groups of 3 columns each. However, although I was using bootstrap, I was trying to separate these groups into different parent divs. I also wanted to make something generically useful.
I approached it with 2 ng-repeat
as below:
<div ng-repeat="items in quotes" ng-if="!($index % 3)">
<div ng-repeat="quote in quotes" ng-if="$index <= $parent.$index + 2 && $index >= $parent.$index">
... some content ...
</div>
</div>
This makes it very easy to change to a different number of columns, and separated out into several parent divs.
If statement in select (ORACLE)
So simple you can use case statement here.
CASE WHEN ISSUE_DIVISION = ISSUE_DIVISION_2 THEN
CASE WHEN ISSUE_DIVISION is null then "Null Value found" //give your option
Else 1 End
ELSE 0 END As Issue_Division_Result
UIView touch event in controller
Updating @Crashalot's answer for Swift 3.x:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
let currentPoint = touch.location(in: self)
// do something with your currentPoint
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
let currentPoint = touch.location(in: self)
// do something with your currentPoint
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
let currentPoint = touch.location(in: self)
// do something with your currentPoint
}
}
Run AVD Emulator without Android Studio
(Only for Windows)
Why to torture yourself? Make a Simple BAT file ! :
- Open Notepad
- Create the command as shown below
- Save as *.bat
- (Optional) Create a shortcut to that *.bat, rename shortcut and change icon
Here is the command:
cd /d yourSdkPath\emulator && emulator -avd yourAVDName
Example:
cd /d D:\Android_SDK\emulator && emulator -avd Nexus_5_API_28
Returning a C string from a function
A char
is only a single one-byte character. It can't store the string of characters, nor is it a pointer (which you apparently cannot have). Therefore you cannot solve your problem without using pointers (which char[]
is syntactic sugar for).
SQL Server IF NOT EXISTS Usage?
Have you verified that there is in fact a row where Staff_Id = @PersonID? What you've posted works fine in a test script, assuming the row exists. If you comment out the insert statement, then the error is raised.
set nocount on
create table Timesheet_Hours (Staff_Id int, BookedHours int, Posted_Flag bit)
insert into Timesheet_Hours (Staff_Id, BookedHours, Posted_Flag) values (1, 5.5, 0)
declare @PersonID int
set @PersonID = 1
IF EXISTS
(
SELECT 1
FROM Timesheet_Hours
WHERE Posted_Flag = 1
AND Staff_Id = @PersonID
)
BEGIN
RAISERROR('Timesheets have already been posted!', 16, 1)
ROLLBACK TRAN
END
ELSE
IF NOT EXISTS
(
SELECT 1
FROM Timesheet_Hours
WHERE Staff_Id = @PersonID
)
BEGIN
RAISERROR('Default list has not been loaded!', 16, 1)
ROLLBACK TRAN
END
ELSE
print 'No problems here'
drop table Timesheet_Hours
How to find item with max value using linq?
With EF or LINQ to SQL:
var item = db.Items.OrderByDescending(i => i.Value).FirstOrDefault();
With LINQ to Objects I suggest to use morelinq extension MaxBy
(get morelinq from nuget):
var item = items.MaxBy(i => i.Value);
How do I send an HTML email?
You can use setText(java.lang.String text,
boolean html) from MimeMessageHelper
:
MimeMessage mimeMsg = javaMailSender.createMimeMessage();
MimeMessageHelper msgHelper = new MimeMessageHelper(mimeMsg, false, "utf-8");
boolean isHTML = true;
msgHelper.setText("<h1>some html</h1>", isHTML);
But you need to:
mimeMsg.saveChanges();
Before:
javaMailSender.send(mimeMsg);
When do I need to use AtomicBoolean in Java?
Excerpt from the package description
Package java.util.concurrent.atomic description: A small toolkit of classes that support lock-free thread-safe programming on single variables.[...]
The specifications of these methods enable implementations to employ efficient machine-level atomic instructions that are available on contemporary processors.[...]
Instances of classes AtomicBoolean, AtomicInteger, AtomicLong, and AtomicReference each provide access and updates to a single variable of the corresponding type.[...]
The memory effects for accesses and updates of atomics generally follow the rules for volatiles:
- get has the memory effects of reading a volatile variable.
- set has the memory effects of writing (assigning) a volatile variable.
- weakCompareAndSet atomically reads and conditionally writes a variable, is ordered with respect to other memory operations on that variable, but otherwise acts as an ordinary non-volatile memory operation.
- compareAndSet and all other read-and-update operations such as getAndIncrement have the memory effects of both reading and writing volatile variables.
How to break out of jQuery each Loop
To break
a $.each
or $(selector).each
loop, you have to return false
in the loop callback.
Returning true
skips to the next iteration, equivalent to a continue
in a normal loop.
$.each(array, function(key, value) {
if(value === "foo") {
return false; // breaks
}
});
// or
$(selector).each(function() {
if (condition) {
return false;
}
});
Cannot find firefox binary in PATH. Make sure firefox is installed. OS appears to be: VISTA
I got this error message while running tests in Visual Studio: Firefox simply wouldn't load and I got OP's error message.
I manually opened Firefox and found out that it needed to update itself (it did so before loading). Once finished I reran the test suite and Firefox showed up nicely, the tests were properly ran. If you get this error all of a sudden please try this answer before updating anything on your machine.
Creating a fixed sidebar alongside a centered Bootstrap 3 grid
As drew_w said, you can find a good example here.
HTML
<div id="wrapper">
<div id="sidebar-wrapper">
<ul class="sidebar-nav">
<li class="sidebar-brand"><a href="#">Home</a></li>
<li><a href="#">Another link</a></li>
<li><a href="#">Next link</a></li>
<li><a href="#">Last link</a></li>
</ul>
</div>
<div id="page-content-wrapper">
<div class="page-content">
<div class="container">
<div class="row">
<div class="col-md-12">
<!-- content of page -->
</div>
</div>
</div>
</div>
</div>
</div>
CSS
#wrapper {
padding-left: 250px;
transition: all 0.4s ease 0s;
}
#sidebar-wrapper {
margin-left: -250px;
left: 250px;
width: 250px;
background: #CCC;
position: fixed;
height: 100%;
overflow-y: auto;
z-index: 1000;
transition: all 0.4s ease 0s;
}
#page-content-wrapper {
width: 100%;
}
.sidebar-nav {
position: absolute;
top: 0;
width: 250px;
list-style: none;
margin: 0;
padding: 0;
}
@media (max-width:767px) {
#wrapper {
padding-left: 0;
}
#sidebar-wrapper {
left: 0;
}
#wrapper.active {
position: relative;
left: 250px;
}
#wrapper.active #sidebar-wrapper {
left: 250px;
width: 250px;
transition: all 0.4s ease 0s;
}
}
JSFIDDLE
How do you use the "WITH" clause in MySQL?
Mysql Developers Team announced that version 8.0 will have Common Table Expressions in MySQL (CTEs). So it will be possible to write queries like this:
WITH RECURSIVE my_cte AS
(
SELECT 1 AS n
UNION ALL
SELECT 1+n FROM my_cte WHERE n<10
)
SELECT * FROM my_cte;
+------+
| n |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
| 10 |
+------+
10 rows in set (0,00 sec)
How do I read from parameters.yml in a controller in symfony2?
In Symfony 2.6 and older versions, to get a parameter in a controller - you should get the container first, and then - the needed parameter.
$this->container->getParameter('api_user');
This documentation chapter explains it.
While $this->get()
method in a controller will load a service (doc)
In Symfony 2.7 and newer versions, to get a parameter in a controller you can use the following:
$this->getParameter('api_user');
Define css class in django Forms
Here is another solution for adding class definitions to the widgets after declaring the fields in the class.
def __init__(self, *args, **kwargs):
super(SampleClass, self).__init__(*args, **kwargs)
self.fields['name'].widget.attrs['class'] = 'my_class'
Test class with a new() call in it with Mockito
You can use a factory to create the login context. Then you can mock the factory and return whatever you want for your test.
public class TestedClass {
private final LoginContextFactory loginContextFactory;
public TestedClass(final LoginContextFactory loginContextFactory) {
this.loginContextFactory = loginContextFactory;
}
public LoginContext login(String user, String password) {
LoginContext lc = loginContextFactory.createLoginContext();
}
}
public interface LoginContextFactory {
public LoginContext createLoginContext();
}
Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL?
All of these are kinds of indices.
primary: must be unique, is an index, is (likely) the physical index, can be only one per table.
unique: as it says. You can't have more than one row with a tuple of this value. Note that since a unique key can be over more than one column, this doesn't necessarily mean that each individual column in the index is unique, but that each combination of values across these columns is unique.
index: if it's not primary or unique, it doesn't constrain values inserted into the table, but it does allow them to be looked up more efficiently.
fulltext: a more specialized form of indexing that allows full text search. Think of it as (essentially) creating an "index" for each "word" in the specified column.
Hiding a password in a python script (insecure obfuscation only)
More homegrown appraoch rather than converting authentication / passwords / username to encrytpted details. FTPLIB is just the example.
"pass.csv" is the csv file name
Save password in CSV like below :
user_name
user_password
(With no column heading)
Reading the CSV and saving it to a list.
Using List elelments as authetntication details.
Full code.
import os
import ftplib
import csv
cred_detail = []
os.chdir("Folder where the csv file is stored")
for row in csv.reader(open("pass.csv","rb")):
cred_detail.append(row)
ftp = ftplib.FTP('server_name',cred_detail[0][0],cred_detail[1][0])
While, Do While, For loops in Assembly Language (emu8086)
For-loops:
For-loop in C:
for(int x = 0; x<=3; x++)
{
//Do something!
}
The same loop in 8086 assembler:
xor cx,cx ; cx-register is the counter, set to 0
loop1 nop ; Whatever you wanna do goes here, should not change cx
inc cx ; Increment
cmp cx,3 ; Compare cx to the limit
jle loop1 ; Loop while less or equal
That is the loop if you need to access your index (cx). If you just wanna to something 0-3=4 times but you do not need the index, this would be easier:
mov cx,4 ; 4 iterations
loop1 nop ; Whatever you wanna do goes here, should not change cx
loop loop1 ; loop instruction decrements cx and jumps to label if not 0
If you just want to perform a very simple instruction a constant amount of times, you could also use an assembler-directive which will just hardcore that instruction
times 4 nop
Do-while-loops
Do-while-loop in C:
int x=1;
do{
//Do something!
}
while(x==1)
The same loop in assembler:
mov ax,1
loop1 nop ; Whatever you wanna do goes here
cmp ax,1 ; Check wether cx is 1
je loop1 ; And loop if equal
While-loops
While-loop in C:
while(x==1){
//Do something
}
The same loop in assembler:
jmp loop1 ; Jump to condition first
cloop1 nop ; Execute the content of the loop
loop1 cmp ax,1 ; Check the condition
je cloop1 ; Jump to content of the loop if met
For the for-loops you should take the cx-register because it is pretty much standard. For the other loop conditions you can take a register of your liking. Of course replace the no-operation instruction with all the instructions you wanna perform in the loop.
How to import a csv file into MySQL workbench?
It seems a little tricky since it really had bothered me for a long time.
You just need to open the table (right click the "Select Rows- Limit 10000") and you will open a new window. In this new window, you will find "import icon".
SELECT * FROM multiple tables. MySQL
You will have the duplicate values for name and price here. And ids are duplicate in the drinks_photos table.There is no way you can avoid them.Also what exactly you want the output ?
Difference between Static methods and Instance methods
The basic paradigm in Java is that you write classes, and that those classes are instantiated. Instantiated objects (an instance of a class) have attributes associated with them (member variables) that affect their behavior; when the instance has its method executed it will refer to these variables.
However, all objects of a particular type might have behavior that is not dependent at all on member variables; these methods are best made static. By being static, no instance of the class is required to run the method.
You can do this to execute a static method:
MyClass.staticMethod(); // Simply refers to the class's static code
But to execute a non-static method, you must do this:
MyClass obj = new MyClass();//Create an instance
obj.nonstaticMethod(); // Refer to the instance's class's code
On a deeper level the compiler, when it puts a class together, collects pointers to methods and attaches them to the class. When those methods are executed it follows the pointers and executes the code at the far end. If a class is instantiated, the created object contains a pointer to the "virtual method table", which points to the methods to be called for that particular class in the inheritance hierarchy. However, if the method is static, no "virtual method table" is needed: all calls to that method go to the exact same place in memory to execute the exact same code. For that reason, in high-performance systems it's better to use a static method if you are not reliant on instance variables.
NSDate get year/month/day
Here's the solution in Swift:
let todayDate = NSDate()
let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
// Use a mask to extract the required components. Extract only the required components, since it'll be expensive to compute all available values.
let components = calendar.components(.CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay, fromDate: todayDate)
var (year, month, date) = (components.year, components.month, components.day)
How to dump a table to console?
Format as JSON (you can "beautify" in IDE later):
local function format_any_value(obj, buffer)
local _type = type(obj)
if _type == "table" then
buffer[#buffer + 1] = '{"'
for key, value in next, obj, nil do
buffer[#buffer + 1] = tostring(key) .. '":'
format_any_value(value, buffer)
buffer[#buffer + 1] = ',"'
end
buffer[#buffer] = '}' -- note the overwrite
elseif _type == "string" then
buffer[#buffer + 1] = '"' .. obj .. '"'
elseif _type == "boolean" or _type == "number" then
buffer[#buffer + 1] = tostring(obj)
else
buffer[#buffer + 1] = '"???' .. _type .. '???"'
end
end
Usage:
local function format_as_json(obj)
if obj == nil then return "null" else
local buffer = {}
format_any_value(obj, buffer)
return table.concat(buffer)
end
end
local function print_as_json(obj)
print(_format_as_json(obj))
end
print_as_json {1, 2, 3}
print_as_json(nil)
print_as_json("string")
print_as_json {[1] = 1, [2] = 2, three = { { true } }, four = "four"}
BTW, I also wrote several other solutions: a very fast one, and one with special characters escaping: https://github.com/vn971/fast_json_encode
Can I simultaneously declare and assign a variable in VBA?
In some cases the whole need for declaring a variable can be avoided by using With
statement.
For example,
Dim fd As Office.FileDialog
Set fd = Application.FileDialog(msoFileDialogSaveAs)
If fd.Show Then
'use fd.SelectedItems(1)
End If
this can be rewritten as
With Application.FileDialog(msoFileDialogSaveAs)
If .Show Then
'use .SelectedItems(1)
End If
End With
ActiveXObject is not defined and can't find variable: ActiveXObject
ActiveXObject
is non-standard and only supported by Internet Explorer on Windows.
There is no native cross browser way to write to the file system without using plugins, even the draft File API gives read only access.
If you want to work cross platform, then you need to look at such things as signed Java applets (keeping in mind that that will only work on platforms for which the Java runtime is available).
Download File Using jQuery
Here's a nice article that shows many ways of hiding files from search engines:
http://antezeta.com/news/avoid-search-engine-indexing
JavaScript isn't a good way not to index a page; it won't prevent users from linking directly to your files (and thus revealing it to crawlers), and as Rob mentioned, wouldn't work for all users.
An easy fix is to add the rel="nofollow"
attribute, though again, it's not complete without robots.txt.
<a href="uploads/file.doc" rel="nofollow">Download Here</a>
Jenkins Host key verification failed
Jenkins is a service account, it doesn't have a shell by design. It is generally accepted that service accounts. shouldn't be able to log in interactively.
To resolve "Jenkins Host key verification failed", do the following steps. I have used mercurial with jenkins.
1)Execute following commands on terminal
$ sudo su -s /bin/bash jenkins
provide password
2)Generate public private key using the following command:
ssh-keygen
you can see output as ::
Generating public/private rsa key pair.
Enter file in which to save the key (/var/lib/jenkins/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
3)Press Enter --> Do not give any passphrase--> press enter
Key has been generated
4) go to --> cat /var/lib/jenkins/.ssh/id_rsa.pub
5) Copy key from id_rsa.pub
6)Exit from bash
7) ssh@yourrepository
8) vi .ssh/authorized_keys
9) Paste the key
10) exit
11)Manually login to mercurial server
Note: Pls do manually login otherwise jenkins will again give error "host verification failed"
12)once manually done, Now go to Jenkins and give build
Enjoy!!!
Good Luck
EXEC sp_executesql with multiple parameters
maybe this help :
declare
@statement AS NVARCHAR(MAX)
,@text1 varchar(50)='hello'
,@text2 varchar(50)='world'
set @statement = '
select '''+@text1+''' + '' beautifull '' + ''' + @text2 + '''
'
exec sp_executesql @statement;
this is same as below :
select @text1 + ' beautifull ' + @text2
Transpose a matrix in Python
If we wanted to return the same matrix we would write:
return [[ m[row][col] for col in range(0,width) ] for row in range(0,height) ]
What this does is it iterates over a matrix m by going through each row and returning each element in each column.
So the order would be like:
[[1,2,3],
[4,5,6],
[7,8,9]]
Now for question 3, we instead want to go column by column, returning each element in each row.
So the order would be like:
[[1,4,7],
[2,5,8],
[3,6,9]]
Therefore just switch the order in which we iterate:
return [[ m[row][col] for row in range(0,height) ] for col in range(0,width) ]
Merge two HTML table cells
Add an attribute colspan
(abbriviation for 'column span') in your top cell (<td>
) and set its value to 2.
Your table should resembles the following;
<table>
<tr>
<td colspan = "2">
<!-- Merged Columns -->
</td>
</tr>
<tr>
<td>
<!-- Column 1 -->
</td>
<td>
<!-- Column 2 -->
</td>
</tr>
</table>
See also
W3 official docs on HTML Tables
MVC Form not able to post List of objects
Your model is null
because the way you're supplying the inputs to your form means the model binder has no way to distinguish between the elements. Right now, this code:
@foreach (var planVM in Model)
{
@Html.Partial("_partialView", planVM)
}
is not supplying any kind of index to those items. So it would repeatedly generate HTML output like this:
<input type="hidden" name="yourmodelprefix.PlanID" />
<input type="hidden" name="yourmodelprefix.CurrentPlan" />
<input type="checkbox" name="yourmodelprefix.ShouldCompare" />
However, as you're wanting to bind to a collection, you need your form elements to be named with an index, such as:
<input type="hidden" name="yourmodelprefix[0].PlanID" />
<input type="hidden" name="yourmodelprefix[0].CurrentPlan" />
<input type="checkbox" name="yourmodelprefix[0].ShouldCompare" />
<input type="hidden" name="yourmodelprefix[1].PlanID" />
<input type="hidden" name="yourmodelprefix[1].CurrentPlan" />
<input type="checkbox" name="yourmodelprefix[1].ShouldCompare" />
That index is what enables the model binder to associate the separate pieces of data, allowing it to construct the correct model. So here's what I'd suggest you do to fix it. Rather than looping over your collection, using a partial view, leverage the power of templates instead. Here's the steps you'd need to follow:
- Create an
EditorTemplates
folder inside your view's current folder (e.g. if your view is Home\Index.cshtml
, create the folder Home\EditorTemplates
).
- Create a strongly-typed view in that directory with the name that matches your model. In your case that would be
PlanCompareViewModel.cshtml
.
Now, everything you have in your partial view wants to go in that template:
@model PlanCompareViewModel
<div>
@Html.HiddenFor(p => p.PlanID)
@Html.HiddenFor(p => p.CurrentPlan)
@Html.CheckBoxFor(p => p.ShouldCompare)
<input type="submit" value="Compare"/>
</div>
Finally, your parent view is simplified to this:
@model IEnumerable<PlanCompareViewModel>
@using (Html.BeginForm("ComparePlans", "Plans", FormMethod.Post, new { id = "compareForm" }))
{
<div>
@Html.EditorForModel()
</div>
}
DisplayTemplates
and EditorTemplates
are smart enough to know when they are handling collections. That means they will automatically generate the correct names, including indices, for your form elements so that you can correctly model bind to a collection.
What is the preferred syntax for initializing a dict: curly brace literals {} or the dict() function?
Curly braces. Passing keyword arguments into dict()
, though it works beautifully in a lot of scenarios, can only initialize a map if the keys are valid Python identifiers.
This works:
a = {'import': 'trade', 1: 7.8}
a = dict({'import': 'trade', 1: 7.8})
This won't work:
a = dict(import='trade', 1=7.8)
It will result in the following error:
a = dict(import='trade', 1=7.8)
^
SyntaxError: invalid syntax
jQuery how to bind onclick event to dynamically added HTML element
A little late to the party but I thought I would try to clear up some common misconceptions in jQuery event handlers. As of jQuery 1.7, .on()
should be used instead of the deprecated .live()
, to delegate event handlers to elements that are dynamically created at any point after the event handler is assigned.
That said, it is not a simple of switching live
for on
because the syntax is slightly different:
New method (example 1):
$(document).on('click', '#someting', function(){
});
Deprecated method (example 2):
$('#something').live(function(){
});
As shown above, there is a difference. The twist is .on()
can actually be called similar to .live()
, by passing the selector to the jQuery function itself:
Example 3:
$('#something').on('click', function(){
});
However, without using $(document)
as in example 1, example 3 will not work for dynamically created elements. The example 3 is absolutely fine if you don't need the dynamic delegation.
Should $(document).on() be used for everything?
It will work but if you don't need the dynamic delegation, it would be more appropriate to use example 3 because example 1 requires slightly more work from the browser. There won't be any real impact on performance but it makes sense to use the most appropriate method for your use.
Should .on() be used instead of .click() if no dynamic delegation is needed?
Not necessarily. The following is just a shortcut for example 3:
$('#something').click(function(){
});
The above is perfectly valid and so it's really a matter of personal preference as to which method is used when no dynamic delegation is required.
References:
Should image size be defined in the img tag height/width attributes or in CSS?
I'm using contentEditable
to allow rich text editing in my app. I don't know how it slips through, but when an image is inserted, and then resized (by dragging the anchors on its side), it generates something like this:
<img style="width:55px;height:55px" width="100" height="100" src="pic.gif" border=0/>
(subsequent testing shown that inserted images did not contain this "rogue" style attr+param).
When rendered by the browser (IE7), the width and height in the style overrides the img width/height param (so the image is shown like how I wanted it.. resized to 55px x 55px. So everything went well so it seems.
When I output the page to a ms-word document via setting the mime type application/msword or pasting the browser rendering to msword document, all the images reverted back to its default size. I finally found out that msword is discarding the style and using the img width and height tag (which has the value of the original image size).
Took me a while to found this out. Anyway... I've coded a javascript function to traverse all tags and "transferring" the img style.width and style.height values into the img.width and img.height, then clearing both the values in style, before I proceed saving this piece of html/richtext data into the database.
cheers.
opps.. my answer is.. no. leave both attributes directly under img, rather than style.
How can I get sin, cos, and tan to use degrees instead of radians?
You can use a function like this to do the conversion:
function toDegrees (angle) {
return angle * (180 / Math.PI);
}
Note that functions like sin
, cos
, and so on do not return angles, they take angles as input. It seems to me that it would be more useful to you to have a function that converts a degree input to radians, like this:
function toRadians (angle) {
return angle * (Math.PI / 180);
}
which you could use to do something like tan(toRadians(45))
.
How to parse this string in Java?
public class Test {
public static void main(String args[]) {
String s = "pre/fix/dir1/dir2/dir3/dir4/..";
String prefix = "pre/fix";
String[] tokens = s.substring(prefix.length()).split("/");
for (int i=0; i<tokens.length; i++) {
System.out.println(tokens[i]);
}
}
}
Django request.GET
Here is a good way to do it.
from django.utils.datastructures import MultiValueDictKeyError
try:
message = 'You submitted: %r' % request.GET['q']
except MultiValueDictKeyError:
message = 'You submitted nothing!'
You don't need to check again if q is in GET request. The call in the QueryDict.get already does that to you.
SQL Server - inner join when updating
This should do it:
UPDATE ProductReviews
SET ProductReviews.status = '0'
FROM ProductReviews
INNER JOIN products
ON ProductReviews.pid = products.id
WHERE ProductReviews.id = '17190'
AND products.shopkeeper = '89137'
difference between width auto and width 100 percent
The initial width of a block level element like div or p is auto.
Use width:auto to undo explicitly specified widths.
if you specify width:100%, the element’s total width will be 100% of its containing block plus any horizontal margin, padding and border.
So, next time you find yourself setting the width of a block level element to 100% to make it occupy all available width, consider if what you really want is setting it to auto.
Passing array in GET for a REST call
Instead of using http GET, use http POST. And JSON. Or XML
This is how your request stream to the server would look like.
POST /appointments HTTP/1.0
Content-Type: application/json
Content-Length: (calculated by your utility)
{users: [user:{id:id1}, user:{id:id2}]}
Or in XML,
POST /appointments HTTP/1.0
Content-Type: application/json
Content-Length: (calculated by your utility)
<users><user id='id1'/><user id='id2'/></users>
You could certainly continue using GET as you have proposed, as it is certainly simpler.
/appointments?users=1d1,1d2
Which means you would have to keep your data structures very simple.
However, if/when your data structure gets more complex, http GET and without JSON, your programming and ability to recognise the data gets very difficult.
Therefore,unless you could keep your data structure simple, I urge you adopt a data transfer framework. If your requests are browser based, the industry usual practice is JSON. If your requests are server-server, than XML is the most convenient framework.
JQuery
If your client is a browser and you are not using GWT, you should consider using jquery REST. Google on RESTful services with jQuery.
Difference between links and depends_on in docker_compose.yml
The post needs an update after the links
option is deprecated.
Basically, links
is no longer needed because its main purpose, making container reachable by another by adding environment variable, is included implicitly with network
. When containers are placed in the same network, they are reachable by each other using their container name and other alias as host.
For docker run
, --link
is also deprecated and should be replaced by a custom network.
docker network create mynet
docker run -d --net mynet --name container1 my_image
docker run -it --net mynet --name container1 another_image
depends_on
expresses start order (and implicitly image pulling order), which was a good side effect of links
.
How to show/hide if variable is null
To clarify, the above example does work, my code in the example did not work for unrelated reasons.
If myvar is false, null or has never been used before (i.e. $scope.myvar or $rootScope.myvar never called), the div will not show. Once any value has been assigned to it, the div will show, except if the value is specifically false.
The following will cause the div to show:
$scope.myvar = "Hello World";
or
$scope.myvar = true;
The following will hide the div:
$scope.myvar = null;
or
$scope.myvar = false;
Can overridden methods differ in return type?
YES it can be possible
class base {
base show(){
System.out.println("base class");
return new base();
}
}
class sub extends base{
sub show(){
System.out.println("sub class");
return new sub();
}
}
class inheritance{
public static void main(String []args) {
sub obj=new sub();
obj.show();
}
}
dbms_lob.getlength() vs. length() to find blob size in oracle
length
and dbms_lob.getlength
return the number of characters when applied to a CLOB (Character LOB). When applied to a BLOB (Binary LOB), dbms_lob.getlength
will return the number of bytes, which may differ from the number of characters in a multi-byte character set.
As the documentation doesn't specify what happens when you apply length
on a BLOB, I would advise against using it in that case. If you want the number of bytes in a BLOB, use dbms_lob.getlength
.
Where do I find the definition of size_t?
This way you always know what the size is, because a specific type is dedicated to sizes. The very own question shows that it can be an issue: is it an int
or an unsigned int
? Also, what is the magnitude (short
, int
, long
, etc.)?
Because there is a specific type assigned, you don't have to worry about the length or the signed-ness.
The actual definition can be found in the C++ Reference Library, which says:
Type: size_t
(Unsigned integral type)
Header: <cstring>
size_t
corresponds to the integral data type returned by the language operator sizeof
and is defined in the <cstring>
header file (among others) as an unsigned integral type.
In <cstring>
, it is used as the type of the parameter num
in the functions memchr
, memcmp
, memcpy
, memmove
, memset
, strncat
, strncmp
, strncpy
and strxfrm
, which in all cases it is used to specify the maximum number of bytes or characters the function has to affect.
It is also used as the return type for strcspn
, strlen
, strspn
and strxfrm
to return sizes and lengths.
Plot data in descending order as appears in data frame
You want reorder()
. Here is an example with dummy data
set.seed(42)
df <- data.frame(Category = sample(LETTERS), Count = rpois(26, 6))
require("ggplot2")
p1 <- ggplot(df, aes(x = Category, y = Count)) +
geom_bar(stat = "identity")
p2 <- ggplot(df, aes(x = reorder(Category, -Count), y = Count)) +
geom_bar(stat = "identity")
require("gridExtra")
grid.arrange(arrangeGrob(p1, p2))
Giving:
Use reorder(Category, Count)
to have Category
ordered from low-high.
ReactJS - Add custom event listener to component
I recommend using React.createRef()
and ref=this.elementRef
to get the DOM element reference instead of ReactDOM.findDOMNode(this)
. This way you can get the reference to the DOM element as an instance variable.
import React, { Component } from 'react';
import ReactDOM from 'react-dom';
class MenuItem extends Component {
constructor(props) {
super(props);
this.elementRef = React.createRef();
}
handleNVFocus = event => {
console.log('Focused: ' + this.props.menuItem.caption.toUpperCase());
}
componentDidMount() {
this.elementRef.addEventListener('nv-focus', this.handleNVFocus);
}
componentWillUnmount() {
this.elementRef.removeEventListener('nv-focus', this.handleNVFocus);
}
render() {
return (
<element ref={this.elementRef} />
)
}
}
export default MenuItem;
EntityType has no key defined error
The reason why EF framework prompt 'no key' is that EF framework needs a primary key in database. To declaratively tell EF which property the key is, you add a [Key]
annotation. Or, the quickest way, add an ID
property. Then, the EF framework will take ID
as the primary key by default.
Iterating over Numpy matrix rows to apply a function each?
Here's my take if you want to try using multiprocesses to process each row of numpy array,
from multiprocessing import Pool
import numpy as np
def my_function(x):
pass # do something and return something
if __name__ == '__main__':
X = np.arange(6).reshape((3,2))
pool = Pool(processes = 4)
results = pool.map(my_function, map(lambda x: x, X))
pool.close()
pool.join()
pool.map take in a function and an iterable.
I used 'map' function to create an iterator over each rows of the array.
Maybe there's a better to create the iterable though.
How to stop a PowerShell script on the first error?
You need slightly different error handling for powershell functions and for calling exe's, and you need to be sure to tell the caller of your script that it has failed. Building on top of Exec
from the library Psake, a script that has the structure below will stop on all errors, and is usable as a base template for most scripts.
Set-StrictMode -Version latest
$ErrorActionPreference = "Stop"
# Taken from psake https://github.com/psake/psake
<#
.SYNOPSIS
This is a helper function that runs a scriptblock and checks the PS variable $lastexitcode
to see if an error occcured. If an error is detected then an exception is thrown.
This function allows you to run command-line programs without having to
explicitly check the $lastexitcode variable.
.EXAMPLE
exec { svn info $repository_trunk } "Error executing SVN. Please verify SVN command-line client is installed"
#>
function Exec
{
[CmdletBinding()]
param(
[Parameter(Position=0,Mandatory=1)][scriptblock]$cmd,
[Parameter(Position=1,Mandatory=0)][string]$errorMessage = ("Error executing command {0}" -f $cmd)
)
& $cmd
if ($lastexitcode -ne 0) {
throw ("Exec: " + $errorMessage)
}
}
Try {
# Put all your stuff inside here!
# powershell functions called as normal and try..catch reports errors
New-Object System.Net.WebClient
# call exe's and check their exit code using Exec
Exec { setup.exe }
} Catch {
# tell the caller it has all gone wrong
$host.SetShouldExit(-1)
throw
}
struct.error: unpack requires a string argument of length 4
The struct module mimics C structures. It takes more CPU cycles for a processor to read a 16-bit word on an odd address or a 32-bit dword on an address not divisible by 4, so structures add "pad bytes" to make structure members fall on natural boundaries. Consider:
struct { 11
char a; 012345678901
short b; ------------
char c; axbbcxxxdddd
int d;
};
This structure will occupy 12 bytes of memory (x being pad bytes).
Python works similarly (see the struct documentation):
>>> import struct
>>> struct.pack('BHBL',1,2,3,4)
'\x01\x00\x02\x00\x03\x00\x00\x00\x04\x00\x00\x00'
>>> struct.calcsize('BHBL')
12
Compilers usually have a way of eliminating padding. In Python, any of =<>! will eliminate padding:
>>> struct.calcsize('=BHBL')
8
>>> struct.pack('=BHBL',1,2,3,4)
'\x01\x02\x00\x03\x04\x00\x00\x00'
Beware of letting struct handle padding. In C, these structures:
struct A { struct B {
short a; int a;
char b; char b;
}; };
are typically 4 and 8 bytes, respectively. The padding occurs at the end of the structure in case the structures are used in an array. This keeps the 'a' members aligned on correct boundaries for structures later in the array. Python's struct module does not pad at the end:
>>> struct.pack('LB',1,2)
'\x01\x00\x00\x00\x02'
>>> struct.pack('LBLB',1,2,3,4)
'\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00\x04'
how to make a specific text on TextView BOLD
Here is better solution if you want to make multiple text to bold. I've improved Eitan's code. thanks Eitan.
public static SpannableStringBuilder makeSectionOfTextBold(String text, String... textToBold) {
SpannableStringBuilder builder = new SpannableStringBuilder(text);
for (String textItem :
textToBold) {
if (textItem.length() > 0 && !textItem.trim().equals("")) {
//for counting start/end indexes
String testText = text.toLowerCase(Locale.US);
String testTextToBold = textItem.toLowerCase(Locale.US);
int startingIndex = testText.indexOf(testTextToBold);
int endingIndex = startingIndex + testTextToBold.length();
if (startingIndex >= 0 && endingIndex >= 0) {
builder.setSpan(new StyleSpan(Typeface.BOLD), startingIndex, endingIndex, 0);
}
}
}
return builder;
}
get current url in twig template?
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) %}
The app
global view variable contains all sorts of useful shortcuts, such as app.session
and app.security.token.user
, that reference the services you might use in a controller.
invalid operands of types int and double to binary 'operator%'
Because %
is only defined for integer types. That's the modulus operator.
5.6.2 of the standard:
The operands of * and / shall have arithmetic or enumeration type; the
operands of % shall have integral or enumeration type. [...]
As Oli pointed out, you can use fmod()
. Don't forget to include math.h
.
How to make a transparent HTML button?
**add the icon top button like this **
_x000D_
_x000D_
#copy_btn{_x000D_
align-items: center;_x000D_
position: absolute;_x000D_
width: 30px;_x000D_
height: 30px;_x000D_
background-color: Transparent;_x000D_
background-repeat:no-repeat;_x000D_
border: none;_x000D_
cursor:pointer;_x000D_
overflow: hidden;_x000D_
outline:none;_x000D_
}_x000D_
.icon_copy{_x000D_
position: absolute;_x000D_
padding: 0px;_x000D_
top:0;_x000D_
left: 0;_x000D_
width: 25px;_x000D_
height: 35px;_x000D_
_x000D_
}
_x000D_
<button id="copy_btn">_x000D_
_x000D_
<img class="icon_copy" src="./assest/copy.svg" alt="Copy Text">_x000D_
</button>
_x000D_
_x000D_
_x000D_
Can I set state inside a useEffect hook
Generally speaking, using setState
inside useEffect
will create an infinite loop that most likely you don't want to cause. There are a couple of exceptions to that rule which I will get into later.
useEffect
is called after each render and when setState
is used inside of it, it will cause the component to re-render which will call useEffect
and so on and so on.
One of the popular cases that using useState
inside of useEffect
will not cause an infinite loop is when you pass an empty array as a second argument to useEffect
like useEffect(() => {....}, [])
which means that the effect function should be called once: after the first mount/render only. This is used widely when you're doing data fetching in a component and you want to save the request data in the component's state.
Wait for shell command to complete
what you proposed with a change at the parenthesis at the Run command worked fine with VBA for me
Dim wsh As Object
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1
Dim errorCode As Integer
wsh.Run "C:\folder\runbat.bat", windowStyle, waitOnReturn
How do I manually configure a DataSource in Java?
One thing you might want to look at is the Commons DBCP project. It provides a BasicDataSource that is configured fairly similarly to your example. To use that you need the database vendor's JDBC JAR in your classpath and you have to specify the vendor's driver class name and the database URL in the proper format.
Edit:
If you want to configure a BasicDataSource
for MySQL, you would do something like this:
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName("com.mysql.jdbc.Driver");
dataSource.setUsername("username");
dataSource.setPassword("password");
dataSource.setUrl("jdbc:mysql://<host>:<port>/<database>");
dataSource.setMaxActive(10);
dataSource.setMaxIdle(5);
dataSource.setInitialSize(5);
dataSource.setValidationQuery("SELECT 1");
Code that needs a DataSource
can then use that.
Can Flask have optional URL parameters?
I know this post is really old but I worked on a package that does this called flask_optional_routes. The code is located at: https://github.com/sudouser2010/flask_optional_routes.
from flask import Flask
from flask_optional_routes import OptionalRoutes
app = Flask(__name__)
optional = OptionalRoutes(app)
@optional.routes('/<user_id>/<user_name>?/')
def foobar(user_id, user_name=None):
return 'it worked!'
if __name__ == "__main__":
app.run(host='0.0.0.0', port=5000)
Load HTML file into WebView
The easiest way would probably be to put your web resources into the assets folder then call:
webView.loadUrl("file:///android_asset/filename.html");
For Complete Communication between Java and Webview See This
Update: The assets folder is usually the following folder:
<project>/src/main/assets
This can be changed in the asset folder configuration setting in your <app>.iml
file as:
<option name=”ASSETS_FOLDER_RELATIVE_PATH” value=”/src/main/assets” />
See Article Where to place the assets folder in Android Studio
Get value when selected ng-option changes
I had the same issue and found a unique solution. This is not best practice, but it may prove simple/helpful for someone. Just use jquery on the id or class or your select tag and you then have access to both the text and the value in the change function. In my case I'm passing in option values via sails/ejs:
<select id="projectSelector" class="form-control" ng-model="ticket.project.id" ng-change="projectChange(ticket)">
<% _.each(projects, function(project) { %>
<option value="<%= project.id %>"><%= project.title %></option>
<% }) %>
</select>
Then in my Angular controller my ng-change function looks like this:
$scope.projectChange = function($scope) {
$scope.project.title=$("#projectSelector option:selected").text();
};
Plot yerr/xerr as shaded region rather than error bars
Ignoring the smooth interpolation between points in your example graph (that would require doing some manual interpolation, or just have a higher resolution of your data), you can use pyplot.fill_between()
:
from matplotlib import pyplot as plt
import numpy as np
x = np.linspace(0, 30, 30)
y = np.sin(x/6*np.pi)
error = np.random.normal(0.1, 0.02, size=y.shape)
y += np.random.normal(0, 0.1, size=y.shape)
plt.plot(x, y, 'k-')
plt.fill_between(x, y-error, y+error)
plt.show()
See also the matplotlib examples.
What does "both" mean in <div style="clear:both">
Clear:both gives you that space between them.
For example your code:
<div style="float:left">Hello</div>
<div style="float:right">Howdy dere pardner</div>
Will currently display as :
Hello ................... Howdy dere pardner
If you add the following to above snippet,
<div style="clear:both"></div>
In between them it will display as:
Hello ................
Howdy dere pardner
giving you that space between hello and Howdy dere pardner.
Js fiiddle http://jsfiddle.net/Qk5vR/1/
How can I make Bootstrap columns all the same height?
alot of css here...
jQuery
$(document).ready(function() {
// Get height of original column you want to match
var box-height = $('.panel:nth-child(1)').outerHeight();
// Output same height on particular element or element(s)
$('.panel').height(box-height);
});
Really simple code no need to play with css, although all options above are perfectly usable.
Jsfiddle
Embed HTML5 YouTube video without iframe?
Here is a example of embedding without an iFrame:
_x000D_
_x000D_
<div style="width: 560px; height: 315px; float: none; clear: both; margin: 2px auto;">
<embed
src="https://www.youtube.com/embed/J---aiyznGQ?autohide=1&autoplay=1"
wmode="transparent"
type="video/mp4"
width="100%" height="100%"
allow="autoplay; encrypted-media; picture-in-picture"
allowfullscreen
title="Keyboard Cat"
>
</div>
_x000D_
_x000D_
_x000D_
compare to regular iframe "embed" code from YouTube:
_x000D_
_x000D_
<iframe
width="560"
height="315"
src="https://www.youtube.com/embed/J---aiyznGQ?autoplay=1"
frameborder="0"
allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture"
allowfullscreen>
</iframe>
_x000D_
_x000D_
_x000D_
and as far as HTML5 goes, use <object>
tag like so (corrected):
_x000D_
_x000D_
<object
style="width: 820px; height: 461.25px; float: none; clear: both; margin: 2px auto;"
data="http://www.youtube.com/embed/J---aiyznGQ?autoplay=1">
</object>
_x000D_
_x000D_
_x000D_
Add colorbar to existing axis
Couldn't add this as a comment, but in case anyone is interested in using the accepted answer with subplots, the divider should be formed on specific axes object (rather than on the numpy.ndarray returned from plt.subplots)
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable
data = np.arange(100, 0, -1).reshape(10, 10)
fig, ax = plt.subplots(ncols=2, nrows=2)
for row in ax:
for col in row:
im = col.imshow(data, cmap='bone')
divider = make_axes_locatable(col)
cax = divider.append_axes('right', size='5%', pad=0.05)
fig.colorbar(im, cax=cax, orientation='vertical')
plt.show()
How to code a modulo (%) operator in C/C++/Obj-C that handles negative numbers
Here is a C function that handles positive OR negative integer OR fractional values for BOTH OPERANDS
#include <math.h>
float mod(float a, float N) {return a - N*floor(a/N);} //return in range [0, N)
This is surely the most elegant solution from a mathematical standpoint. However, I'm not sure if it is robust in handling integers. Sometimes floating point errors creep in when converting int -> fp -> int.
I am using this code for non-int s, and a separate function for int.
NOTE: need to trap N = 0!
Tester code:
#include <math.h>
#include <stdio.h>
float mod(float a, float N)
{
float ret = a - N * floor (a / N);
printf("%f.1 mod %f.1 = %f.1 \n", a, N, ret);
return ret;
}
int main (char* argc, char** argv)
{
printf ("fmodf(-10.2, 2.0) = %f.1 == FAIL! \n\n", fmodf(-10.2, 2.0));
float x;
x = mod(10.2f, 2.0f);
x = mod(10.2f, -2.0f);
x = mod(-10.2f, 2.0f);
x = mod(-10.2f, -2.0f);
return 0;
}
(Note: You can compile and run it straight out of CodePad: http://codepad.org/UOgEqAMA)
Output:
fmodf(-10.2, 2.0) = -0.20 == FAIL!
10.2 mod 2.0 = 0.2
10.2 mod -2.0 = -1.8
-10.2 mod 2.0 = 1.8
-10.2 mod -2.0 = -0.2
Vim: insert the same characters across multiple lines
Updated January 2016
Whilst the accepted answer is a great solution, this is actually slightly fewer keystrokes, and scales better - based in principle on the accepted answer.
- Move the cursor to the
n
in name
.
- Enter visual block mode (ctrlv).
- Press 3j
- Press
I
.
- Type in
vendor_
.
- Press esc.
Note, this has fewer keystrokes than the accepted answer provided (compare Step 3). We just count the number of j actions to perform.
If you have line numbers enabled (as illustrated above), and know the line number you wish to move to, then step 3 can be changed to #G where # is the wanted line number.
In our example above, this would be 4G. However when dealing with just a few line numbers an explicit count works well.
Getting the IP address of the current machine using Java
Posting here tested IP ambiguity workaround code from https://issues.apache.org/jira/browse/JCS-40 (InetAddress.getLocalHost() ambiguous on Linux systems):
/**
* Returns an <code>InetAddress</code> object encapsulating what is most likely the machine's LAN IP address.
* <p/>
* This method is intended for use as a replacement of JDK method <code>InetAddress.getLocalHost</code>, because
* that method is ambiguous on Linux systems. Linux systems enumerate the loopback network interface the same
* way as regular LAN network interfaces, but the JDK <code>InetAddress.getLocalHost</code> method does not
* specify the algorithm used to select the address returned under such circumstances, and will often return the
* loopback address, which is not valid for network communication. Details
* <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4665037">here</a>.
* <p/>
* This method will scan all IP addresses on all network interfaces on the host machine to determine the IP address
* most likely to be the machine's LAN address. If the machine has multiple IP addresses, this method will prefer
* a site-local IP address (e.g. 192.168.x.x or 10.10.x.x, usually IPv4) if the machine has one (and will return the
* first site-local address if the machine has more than one), but if the machine does not hold a site-local
* address, this method will return simply the first non-loopback address found (IPv4 or IPv6).
* <p/>
* If this method cannot find a non-loopback address using this selection algorithm, it will fall back to
* calling and returning the result of JDK method <code>InetAddress.getLocalHost</code>.
* <p/>
*
* @throws UnknownHostException If the LAN address of the machine cannot be found.
*/
private static InetAddress getLocalHostLANAddress() throws UnknownHostException {
try {
InetAddress candidateAddress = null;
// Iterate all NICs (network interface cards)...
for (Enumeration ifaces = NetworkInterface.getNetworkInterfaces(); ifaces.hasMoreElements();) {
NetworkInterface iface = (NetworkInterface) ifaces.nextElement();
// Iterate all IP addresses assigned to each card...
for (Enumeration inetAddrs = iface.getInetAddresses(); inetAddrs.hasMoreElements();) {
InetAddress inetAddr = (InetAddress) inetAddrs.nextElement();
if (!inetAddr.isLoopbackAddress()) {
if (inetAddr.isSiteLocalAddress()) {
// Found non-loopback site-local address. Return it immediately...
return inetAddr;
}
else if (candidateAddress == null) {
// Found non-loopback address, but not necessarily site-local.
// Store it as a candidate to be returned if site-local address is not subsequently found...
candidateAddress = inetAddr;
// Note that we don't repeatedly assign non-loopback non-site-local addresses as candidates,
// only the first. For subsequent iterations, candidate will be non-null.
}
}
}
}
if (candidateAddress != null) {
// We did not find a site-local address, but we found some other non-loopback address.
// Server might have a non-site-local address assigned to its NIC (or it might be running
// IPv6 which deprecates the "site-local" concept).
// Return this non-loopback candidate address...
return candidateAddress;
}
// At this point, we did not find a non-loopback address.
// Fall back to returning whatever InetAddress.getLocalHost() returns...
InetAddress jdkSuppliedAddress = InetAddress.getLocalHost();
if (jdkSuppliedAddress == null) {
throw new UnknownHostException("The JDK InetAddress.getLocalHost() method unexpectedly returned null.");
}
return jdkSuppliedAddress;
}
catch (Exception e) {
UnknownHostException unknownHostException = new UnknownHostException("Failed to determine LAN address: " + e);
unknownHostException.initCause(e);
throw unknownHostException;
}
}
splitting a number into the integer and decimal parts
I have come up with two statements that can divide positive and negative numbers into integers and fractions without compromising accuracy (bit overflow) and speed.
x = 100.1323 # A number to be divided into integers and fractions
# The two statement to divided a number into integers and fractions
i = int(x) # A positive or negative integer
f = (x*1e17-i*1e17)/1e17 # A positive or negative fraction
E.g. 100.1323
-> 100
, 0.1323
or -100.1323
-> -100
, -0.1323
Speedtest
The performance test shows that the two statements are faster than math.modf
, as long as they are not put into their own function or method.
test.py
:
#!/usr/bin/env python
import math
import cProfile
""" Get the performance of both statements and math.modf. """
X = -100.1323 # The number to be divided into integers and fractions
LOOPS = range(5*10**6) # Number of loops
def scenario_a():
""" The integers (i) and the fractions (f)
come out as integer and float. """
for _ in LOOPS:
i = int(X) # -100
f = (X*1e17-i*1e17)/1e17 # -0.1323
def scenario_b():
""" The integers (i) and the fractions (f)
come out as float.
NOTE: The only difference between this
and math.modf is the accuracy. """
for _ in LOOPS:
i = int(X) # -100
i, f = float(i), (X*1e17-i*1e17)/1e17 # (-100.0, -0.1323)
def scenario_c():
""" Performance test of the statements in a function. """
def modf(x):
i = int(x)
return i, (x*1e17-i*1e17)/1e17
for _ in LOOPS:
i, f = modf(X) # (-100, -0.1323)
def scenario_d():
for _ in LOOPS:
f, i = math.modf(X) # (-100.0, -0.13230000000000075)
def scenario_e():
""" Convert the integer part to real integer. """
for _ in LOOPS:
f, i = math.modf(X) # (-100.0, -0.13230000000000075)
i = int(i) # -100
if __name__ == '__main__':
cProfile.run('scenario_a()')
cProfile.run('scenario_b()')
cProfile.run('scenario_c()')
cProfile.run('scenario_d()')
cProfile.run('scenario_e()')
Output:
4 function calls in 1.312 seconds
Ordered by: standard name
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 1.312 1.312 <string>:1(<module>)
1 1.312 1.312 1.312 1.312 test.py:10(scenario_a)
1 0.000 0.000 1.312 1.312 {built-in method builtins.exec}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
4 function calls in 1.887 seconds
Ordered by: standard name
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 1.887 1.887 <string>:1(<module>)
1 1.887 1.887 1.887 1.887 test.py:18(scenario_b)
1 0.000 0.000 1.887 1.887 {built-in method builtins.exec}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
5000004 function calls in 2.797 seconds
Ordered by: standard name
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 2.797 2.797 <string>:1(<module>)
1 1.261 1.261 2.797 2.797 test.py:27(scenario_c)
5000000 1.536 0.000 1.536 0.000 test.py:31(modf)
1 0.000 0.000 2.797 2.797 {built-in method builtins.exec}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
5000004 function calls in 1.852 seconds
Ordered by: standard name
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 1.852 1.852 <string>:1(<module>)
1 1.050 1.050 1.852 1.852 test.py:38(scenario_d)
1 0.000 0.000 1.852 1.852 {built-in method builtins.exec}
5000000 0.802 0.000 0.802 0.000 {built-in method math.modf}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
5000004 function calls in 2.467 seconds
Ordered by: standard name
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 2.467 2.467 <string>:1(<module>)
1 1.652 1.652 2.467 2.467 test.py:42(scenario_e)
1 0.000 0.000 2.467 2.467 {built-in method builtins.exec}
5000000 0.815 0.000 0.815 0.000 {built-in method math.modf}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}
NOTE:
The statement can be faster with modulo, but modulo can not be used to split negative numbers into integer and fraction parts.
i, f = int(x), x*1e17%1e17/1e17 # x can not be negative
Error while retrieving information from the server RPC:s-7:AEC-0 in Google play?
Check that the application on the test device and Google Play developer console really match.
I might have a bit of a special case but it might help someone: First, I had uploaded a package to Google Play that I had created with an ant build script. Second, on the test device, I debugged the same application (or so I thought). I got the "Error while retrieving information from server. [RPC:S-7:AEC-0]", and logcat displayed:
Class not found when unmarshalling: com.google.android.finsky.billing.lightpurchase.PurchaseParams, e: java.lang.ClassNotFoundException: com.google.android.finsky.billing.lightpurchase.PurchaseParams
The problem was that in the ant script, I have aapt
command for modifying the package name. However, Eclipse does not run that command, so there was a package name mismatch between the applications in Google Play and the test device.
What tool to use to draw file tree diagram
The advice to use Graphviz is good: you can generate the dot file and it will do the hard work of measuring strings, doing the layout, etc. Plus it can output the graphs in lot of formats, including vector ones.
I found a Perl program doing precisely that, in a mailing list, but I just can't find it back! I copied the sample dot file and studied it, since I don't know much of this declarative syntax and I wanted to learn a bit more.
Problem: with latest Graphviz, I have errors (or rather, warnings, as the final diagram is generated), both in the original graph and the one I wrote (by hand). Some searches shown this error was found in old versions and disappeared in more recent versions. Looks like it is back.
I still give the file, maybe it can be a starting point for somebody, or maybe it is enough for your needs (of course, you still have to generate it).
digraph tree
{
rankdir=LR;
DirTree [label="Directory Tree" shape=box]
a_Foo_txt [shape=point]
f_Foo_txt [label="Foo.txt", shape=none]
a_Foo_txt -> f_Foo_txt
a_Foo_Bar_html [shape=point]
f_Foo_Bar_html [label="Foo Bar.html", shape=none]
a_Foo_Bar_html -> f_Foo_Bar_html
a_Bar_png [shape=point]
f_Bar_png [label="Bar.png", shape=none]
a_Bar_png -> f_Bar_png
a_Some_Dir [shape=point]
d_Some_Dir [label="Some Dir", shape=ellipse]
a_Some_Dir -> d_Some_Dir
a_VBE_C_reg [shape=point]
f_VBE_C_reg [label="VBE_C.reg", shape=none]
a_VBE_C_reg -> f_VBE_C_reg
a_P_Folder [shape=point]
d_P_Folder [label="P Folder", shape=ellipse]
a_P_Folder -> d_P_Folder
a_Processing_20081117_7z [shape=point]
f_Processing_20081117_7z [label="Processing-20081117.7z", shape=none]
a_Processing_20081117_7z -> f_Processing_20081117_7z
a_UsefulBits_lua [shape=point]
f_UsefulBits_lua [label="UsefulBits.lua", shape=none]
a_UsefulBits_lua -> f_UsefulBits_lua
a_Graphviz [shape=point]
d_Graphviz [label="Graphviz", shape=ellipse]
a_Graphviz -> d_Graphviz
a_Tree_dot [shape=point]
f_Tree_dot [label="Tree.dot", shape=none]
a_Tree_dot -> f_Tree_dot
{
rank=same;
DirTree -> a_Foo_txt -> a_Foo_Bar_html -> a_Bar_png -> a_Some_Dir -> a_Graphviz [arrowhead=none]
}
{
rank=same;
d_Some_Dir -> a_VBE_C_reg -> a_P_Folder -> a_UsefulBits_lua [arrowhead=none]
}
{
rank=same;
d_P_Folder -> a_Processing_20081117_7z [arrowhead=none]
}
{
rank=same;
d_Graphviz -> a_Tree_dot [arrowhead=none]
}
}
> dot -Tpng Tree.dot -o Tree.png
Error: lost DirTree a_Foo_txt edge
Error: lost a_Foo_txt a_Foo_Bar_html edge
Error: lost a_Foo_Bar_html a_Bar_png edge
Error: lost a_Bar_png a_Some_Dir edge
Error: lost a_Some_Dir a_Graphviz edge
Error: lost d_Some_Dir a_VBE_C_reg edge
Error: lost a_VBE_C_reg a_P_Folder edge
Error: lost a_P_Folder a_UsefulBits_lua edge
Error: lost d_P_Folder a_Processing_20081117_7z edge
Error: lost d_Graphviz a_Tree_dot edge
I will try another direction, using Cairo, which is also able to export a number of formats. It is more work (computing positions/offsets) but the structure is simple, shouldn't be too hard.
grep without showing path/file:line
No need to find
. If you are just looking for a pattern within a specific directory, this should suffice:
grep -hn FOO /your/path/*.bar
Where -h
is the parameter to hide the filename, as from man grep
:
-h, --no-filename
Suppress the prefixing of file names on output. This is the default
when there is only one file (or only standard input) to search.
Note that you were using
-H, --with-filename
Print the file name for each match. This is the default when there is
more than one file to search.
How do I drop a function if it already exists?
Here's my take on this:
if(object_id(N'[dbo].[fn_Nth_Pos]', N'FN')) is not null
drop function [dbo].[fn_Nth_Pos];
GO
CREATE FUNCTION [dbo].[fn_Nth_Pos]
(
@find char, --char to find
@search varchar(max), --string to process
@nth int --occurrence
)
RETURNS int
AS
BEGIN
declare @pos int --position of nth occurrence
--init
set @pos = 0
while(@nth > 0)
begin
set @pos = charindex(@find,@search,@pos+1)
set @nth = @nth - 1
end
return @pos
END
GO
--EXAMPLE
declare @files table(name varchar(max));
insert into @files(name) values('abc_1_2_3_4.gif');
insert into @files(name) values('zzz_12_3_3_45.gif');
select
f.name,
dbo.fn_Nth_Pos('_', f.name, 1) as [1st],
dbo.fn_Nth_Pos('_', f.name, 2) as [2nd],
dbo.fn_Nth_Pos('_', f.name, 3) as [3rd],
dbo.fn_Nth_Pos('_', f.name, 4) as [4th]
from
@files f;
AltGr key not working, instead I have to use Ctrl+AltGr
I found a solution for my problem while writing my question !
Going into my remote session i tried two key combinations, and it solved the problem on my Desktop : Alt+Enter and Ctrl+Enter (i don't know which one solved the problem though)
I tried to reproduce the problem, but i couldn't... but i'm almost sure it's one of the key combinations described in the question above (since i experienced this problem several times)
So it seems the problem comes from the use of RDP (windows7 and 8)
Update 2017: Problem occurs on Windows 10 aswell.
What are the best PHP input sanitizing functions?
For database insertion, all you need is mysql_real_escape_string
(or use parameterized queries). You generally don't want to alter data before saving it, which is what would happen if you used htmlentities
. That would lead to a garbled mess later on when you ran it through htmlentities
again to display it somewhere on a webpage.
Use htmlentities
when you are displaying the data on a webpage somewhere.
Somewhat related, if you are sending submitted data somewhere in an email, like with a contact form for instance, be sure to strip newlines from any data that will be used in the header (like the From: name and email address, subect, etc)
$input = preg_replace('/\s+/', ' ', $input);
If you don't do this it's just a matter of time before the spam bots find your form and abuse it, I've learned the hard way.
Linq Syntax - Selecting multiple columns
As the other answers have indicated, you need to use an anonymous type.
As far as syntax is concerned, I personally far prefer method chaining. The method chaining equivalent would be:-
var employee = _db.EMPLOYEEs
.Where(x => x.EMAIL == givenInfo || x.USER_NAME == givenInfo)
.Select(x => new { x.EMAIL, x.ID });
AFAIK, the declarative LINQ syntax is converted to a method call chain similar to this when it is compiled.
UPDATE
If you want the entire object, then you just have to omit the call to Select()
, i.e.
var employee = _db.EMPLOYEEs
.Where(x => x.EMAIL == givenInfo || x.USER_NAME == givenInfo);
CSS transition when class removed
CSS transitions work by defining two states for the object using CSS. In your case, you define how the object looks when it has the class "saved"
and you define how it looks when it doesn't have the class "saved"
(it's normal look). When you remove the class "saved"
, it will transition to the other state according to the transition settings in place for the object without the "saved"
class.
If the CSS transition settings apply to the object (without the "saved"
class), then they will apply to both transitions.
We could help more specifically if you included all relevant CSS you're using to with the HTML you've provided.
My guess from looking at your HTML is that your transition CSS settings only apply to .saved
and thus when you remove it, there are no controls to specify a CSS setting. You may want to add another class ".fade"
that you leave on the object all the time and you can specify your CSS transition settings on that class so they are always in effect.
JQuery/Javascript: check if var exists
It is impossible to determine whether a variable has been declared or not other than using try..catch to cause an error if it hasn't been declared. Test like:
if (typeof varName == 'undefined')
do not tell you if varName
is a variable in scope, only that testing with typeof returned undefined. e.g.
var foo;
typeof foo == 'undefined'; // true
typeof bar == 'undefined'; // true
In the above, you can't tell that foo was declared but bar wasn't. You can test for global variables using in
:
var global = this;
...
'bar' in global; // false
But the global object is the only variable object* you can access, you can't access the variable object of any other execution context.
The solution is to always declare variables in an appropriate context.
- The global object isn't really a variable object, it just has properties that match global variables and provide access to them so it just appears to be one.
Adding an external directory to Tomcat classpath
See also question: Can I create a custom classpath on a per application basis in Tomcat
Tomcat 7 Context hold Loader element. According to docs deployment descriptor (what in <Context>
tag) can be placed in:
$CATALINA_BASE/conf/server.xml
- bad - require server restarts in order to reread config
$CATALINA_BASE/conf/context.xml
- bad - shared across all applications
$CATALINA_BASE/work/$APP.war:/META-INF/context.xml
- bad - require repackaging in order to change config
$CATALINA_BASE/work/[enginename]/[hostname]/$APP/META-INF/context.xml
- nice, but see last option!!
$CATALINA_BASE/webapps/$APP/META-INF/context.xml
- nice, but see last option!!
$CATALINA_BASE/conf/[enginename]/[hostname]/$APP.xml
- best - completely out of application and automatically scanned for changes!!!
Here my config which demonstrate how to use development version of project files out of $CATALINA_BASE
hierarchy (note that I place this file into src/test/resources
dir and intruct Maven to preprocess ${basedir}
placeholders through pom.xml
<filtering>true</filtering>
so after build in new environment I copy it to $CATALINA_BASE/conf/Catalina/localhost/$APP.xml
):
<Context docBase="${basedir}/src/main/webapp"
reloadable="true">
<!-- http://tomcat.apache.org/tomcat-7.0-doc/config/context.html -->
<Resources className="org.apache.naming.resources.VirtualDirContext"
extraResourcePaths="/WEB-INF/classes=${basedir}/target/classes,/WEB-INF/lib=${basedir}/target/${project.build.finalName}/WEB-INF/lib"/>
<Loader className="org.apache.catalina.loader.VirtualWebappLoader"
virtualClasspath="${basedir}/target/classes;${basedir}/target/${project.build.finalName}/WEB-INF/lib"/>
<JarScanner scanAllDirectories="true"/>
<!-- Use development version of JS/CSS files. -->
<Parameter name="min" value="dev"/>
<Environment name="app.devel.ldap" value="USER" type="java.lang.String" override="true"/>
<Environment name="app.devel.permitAll" value="true" type="java.lang.String" override="true"/>
</Context>
UPDATE Tomcat 8 change syntax for <Resources>
and <Loader>
elements, corresponding part now look like:
<Resources>
<PostResources className="org.apache.catalina.webresources.DirResourceSet"
webAppMount="/WEB-INF/classes" base="${basedir}/target/classes" />
<PostResources className="org.apache.catalina.webresources.DirResourceSet"
webAppMount="/WEB-INF/lib" base="${basedir}/target/${project.build.finalName}/WEB-INF/lib" />
</Resources>
How to get the current location in Google Maps Android API v2?
To get the location when the user clicks on a button call this method in the onClick-
void getCurrentLocation() {
Location myLocation = mMap.getMyLocation();
if(myLocation!=null)
{
double dLatitude = myLocation.getLatitude();
double dLongitude = myLocation.getLongitude();
Log.i("APPLICATION"," : "+dLatitude);
Log.i("APPLICATION"," : "+dLongitude);
mMap.addMarker(new MarkerOptions().position(
new LatLng(dLatitude, dLongitude)).title("My Location").icon(BitmapDescriptorFactory.fromBitmap(Utils.getBitmap("pointer_icon.png"))));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(dLatitude, dLongitude), 8));
}
else
{
Toast.makeText(this, "Unable to fetch the current location", Toast.LENGTH_SHORT).show();
}
}
Also make sure that the
setMyLocationEnabled
is set to true.
Try and see if this works...
Min / Max Validator in Angular 2 Final
In my template driven form (Angular 6) I have the following workaround:
<div class='col-sm-2 form-group'>
<label for='amount'>Amount</label>
<input type='number'
id='amount'
name='amount'
required
[ngModel] = 1
[pattern] = "'^[1-9][0-9]*$'"
class='form-control'
#amountInput='ngModel'/>
<span class='text-danger' *ngIf="amountInput.touched && amountInput.invalid">
<p *ngIf="amountInput.errors?.required">This field is <b>required</b>!</p>
<p *ngIf="amountInput.errors?.pattern">This minimum amount is <b>1</b>!</p>
</span>
</div>
Alot of the above examples make use of directives and custom classes which do scale better in more complex forms, but if your looking for a simple numeric min, utilize pattern
as a directive and impose a regex restriction on positive numbers only.
how to call a function from another function in Jquery
wrap you shared code into another function:
<script>
function myFun () {
//do something
}
$(document).ready(function(){
//Load City by State
$(document).on('change', '#billing_state_id', function() {
myFun ();
});
$(document).on('click', '#click_me', function() {
//do something
myFun();
});
});
</script>
How to permanently export a variable in Linux?
A particular example:
I have Java 7 and Java 6 installed, I need to run some builds with 6, others with 7. Therefore I need to dynamically alter JAVA_HOME
so that maven picks up what I want for each build. I did the following:
- created
j6.sh
script which simply does export JAVA_HOME=...
path to j6 install...
- then, as suggested by one of the comments above, whenever I need J6 for a build, I run source
j6.sh
in that respective command terminal. By default, my JAVA_HOME
is set to J7.
Hope this helps.
How to convert Moment.js date to users local timezone?
You do not need to use moment-timezone for this. The main moment.js library has full functionality for working with UTC and the local time zone.
var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).local();
From there you can use any of the functions you might expect:
var s = localDate.format("YYYY-MM-DD HH:mm:ss");
var d = localDate.toDate();
// etc...
Note that by passing testDateUtc
, which is a moment
object, back into the moment()
constructor, it creates a clone. Otherwise, when you called .local()
, it would also change the testDateUtc
value, instead of just the localDate
value. Moments are mutable.
Also note that if your original input contains a time zone offset such as +00:00
or Z
, then you can just parse it directly with moment
. You don't need to use .utc
or .local
. For example:
var localDate = moment("2015-01-30T10:00:00Z");
Java2D: Increase the line width
You should use setStroke
to set a stroke of the Graphics2D
object.
The example at http://www.java2s.com gives you some code examples.
The following code produces the image below:
import java.awt.*;
import java.awt.geom.Line2D;
import javax.swing.*;
public class FrameTest {
public static void main(String[] args) {
JFrame jf = new JFrame("Demo");
Container cp = jf.getContentPane();
cp.add(new JComponent() {
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setStroke(new BasicStroke(10));
g2.draw(new Line2D.Float(30, 20, 80, 90));
}
});
jf.setSize(300, 200);
jf.setVisible(true);
}
}
(Note that the setStroke
method is not available in the Graphics
object. You have to cast it to a Graphics2D
object.)
This post has been rewritten as an article here.
How to ignore ansible SSH authenticity checking?
Use the parameter named as validate_certs to ignore the ssh validation
- ec2_ami:
instance_id: i-0661fa8b45a7531a7
wait: yes
name: ansible
validate_certs: false
tags:
Name: ansible
Service: TestService
By doing this it ignores the ssh validation process
What size should apple-touch-icon.png be for iPad and iPhone?
Yes, bigger than 60x60 are supported. For simplicity, create icons of these 4 sizes:
1) 60x60 <= default
2) 76x76
3) 120x120
4) 152x152
Now, it's preferable to add them as links in your HTML as:
<link rel="apple-touch-icon" href="touch-icon-iphone.png">
<link rel="apple-touch-icon" sizes="76x76" href="touch-icon-ipad.png">
<link rel="apple-touch-icon" sizes="120x120" href="touch-icon-iphone-retina.png">
<link rel="apple-touch-icon" sizes="152x152" href="touch-icon-ipad-retina.png">
You can choose to not declare the 4 links above but just declare a single link, in which case give the highest size of 152x152
or even a size higher than that, say 196x196
. It will always trim down the size for re-purposing. Ensure you mention the size
.
You can also choose not to declare even a single link. Apple mentions that in this scenario, it will lookup the server root first for the size immediately higher that the size it wants (naming format: apple-touch-icon-<size>.png
), and if that's not found then it will next look for the default file:
apple-touch-icon.png
. It's preferable that you define the link(s) as that will minimize the browser querying your server.
Icon necessities:
- use PNG, avoid interlaced
- use 24-bit PNG
- not necessary to use web-safe colors
In versions older than iOS 7, if you don't want it to add effects to your icons, then just add the suffix -precomposed.png
to the file name. (iOS 7 doesn't add effects even without it).
Include headers when using SELECT INTO OUTFILE?
You can use prepared statement with lucek's answer and export dynamically table with columns name in CSV :
--If your table has too many columns
SET GLOBAL group_concat_max_len = 100000000;
--Prepared statement
SET @SQL = ( select CONCAT('SELECT * INTO OUTFILE \'YOUR_PATH\' FIELDS TERMINATED BY \',\' OPTIONALLY ENCLOSED BY \'"\' ESCAPED BY \'\' LINES TERMINATED BY \'\\n\' FROM (SELECT ', GROUP_CONCAT(CONCAT("'",COLUMN_NAME,"'")),' UNION select * from YOUR_TABLE) as tmp') from INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'YOUR_TABLE' AND TABLE_SCHEMA = 'YOUR_SCHEMA' order BY ORDINAL_POSITION );
--Execute it
PREPARE stmt FROM @SQL;
EXECUTE stmt;
Thank lucek.
How to make button fill table cell
For starters:
<p align='center'>
<table width='100%'>
<tr>
<td align='center'><form><input type=submit value="click me" style="width:100%"></form></td>
</tr>
</table>
</p>
Note, if the width of the input button is 100%, you wont need the attribute "align='center'" anymore.
This would be the optimal solution:
<p align='center'>
<table width='100%'>
<tr>
<td><form><input type=submit value="click me" style="width:100%"></form></td>
</tr>
</table>
</p>
How to edit default.aspx on SharePoint site without SharePoint Designer
Go to view all content of the site (http://yourdmain.sharepoint/sitename/_layouts/viewlsts.aspx). Select the document library "Pages" (the "Pages" library are named based on the language you created the site in. I.E. in norwegian the library is named "Sider"). Download the default.aspx to you computer and fix it (remove the web part and the <%Register tag). Save it and upload it back to the library (remember to check in the file).
EDIT:
ahh.. you are not using a publishing site template. Go to site action -> site settings. Under "site administration" select the menu "content and structure" you should now see your default.aspx page. But you cant do much with it...(delete, copy or move)
workaround:
Enable publishing feature to the root web. Add the fixed default.aspx file to the Pages library and change the welcome page to this. Disable the publishing feature (this will delete all other list create from this feature but not the Pages library since one page is in use.). You will now have a new default.aspx page for the root web but the url is changed from sitename/default.aspx to sitename/Pages/default.aspx.
workaround II
Use a feature to change the default.aspx file. The solution is explained here: http://wssguy.com/blogs/dan/archive/2008/10/29/how-to-change-the-default-page-of-a-sharepoint-site-using-a-feature.aspx
jQuery: find element by text
In jQuery documentation it says:
The matching text can appear directly within the selected element, in
any of that element's descendants, or a combination
Therefore it is not enough that you use :contains()
selector, you also need to check if the text you search for is the direct content of the element you are targeting for, something like that:
function findElementByText(text) {
var jSpot = $("b:contains(" + text + ")")
.filter(function() { return $(this).children().length === 0;})
.parent(); // because you asked the parent of that element
return jSpot;
}
How to calculate difference in hours (decimal) between two dates in SQL Server?
Just subtract the two datetime values and multiply by 24:
Select Cast((@DateTime2 - @DateTime1) as Float) * 24.0
a test script might be:
Declare @Dt1 dateTime Set @Dt1 = '12 Jan 2009 11:34:12'
Declare @Dt2 dateTime Set @Dt2 = getdate()
Select Cast((@Dt2 - @Dt1) as Float) * 24.0
This works because all datetimes are stored internally as a pair of integers, the first integer is the number of days since 1 Jan 1900, and the second integer (representing the time) is the number of (1) ticks since Midnight. (For SmallDatetimes the time portion integer is the number of minutes since midnight). Any arithmetic done on the values uses the time portion as a fraction of a day. 6am = 0.25, noon = 0.5, etc... See MSDN link here for more details.
So Cast((@Dt2 - @Dt1) as Float) gives you total days between two datetimes. Multiply by 24 to convert to hours. If you need total minutes, Multiple by Minutes per day (24 * 60 = 1440) instead of 24...
NOTE 1: This is not the same as a dotNet or javaScript tick - this tick is about 3.33 milliseconds.
Php - testing if a radio button is selected and get the value
my form:
<form method="post" action="radio.php">
select your gender:
<input type="radio" name="radioGender" value="female">
<input type="radio" name="radioGender" value="male">
<input type="submit" name="btnSubmit" value="submit">
</form>
my php:
<?php
if (isset($_POST["btnSubmit"])) {
if (isset($_POST["radioGender"])) {
$answer = $_POST['radioGender'];
if ($answer == "female") {
echo "female";
} else {
echo "male";
}
}else{
echo "please select your gender";
}
}
?>
Multiprocessing a for loop?
You can simply use multiprocessing.Pool
:
from multiprocessing import Pool
def process_image(name):
sci=fits.open('{}.fits'.format(name))
<process>
if __name__ == '__main__':
pool = Pool() # Create a multiprocessing Pool
pool.map(process_image, data_inputs) # process data_inputs iterable with pool
Anaconda Navigator won't launch (windows 10)
I was working on my Windows 10 machine and I'm not sure which package "broke" Spyder and Anaconda Navigator, but could have been either, or, or both Kivy-1.10.1 and moviepy-0.2.3.5 which gave me problems. I installed with either pip or conda.
So of course I looked on this site to see what to do to fix. I found how pyqt was probably the issue. I uninstalled pyqt, kivy, and moviepy by using "pip uninstall ". I found where/or how they were installed by "pip list" and "conda list". After they were uninstalled I used "conda install - c anaconda pyqt" to reinstall pyqt. After installing pyqt I launched Spyder with no problems.
How to access the elements of a 2D array?
If you have
a=[[1,1],[2,1],[3,1]]
b=[[1,2],[2,2],[3,2]]
Then
a[1][1]
Will work fine. It points to the second column, second row just like you wanted.
I'm not sure what you did wrong.
To multiply the cells in the third column you can just do
c = [a[2][i] * b[2][i] for i in range(len(a[2]))]
Which will work for any number of rows.
Edit: The first number is the column, the second number is the row, with your current layout. They are both numbered from zero. If you want to switch the order you can do
a = zip(*a)
or you can create it that way:
a=[[1, 2, 3], [1, 1, 1]]
Change the "From:" address in Unix "mail"
In my version of mail ( Debian linux 4.0 ) the following options work for controlling the source / reply addresses
- the -a switch, for additional headers to apply, supplying a From: header on the command line that will be appended to the outgoing mail header
- the $REPLYTO environment variable specifies a Reply-To: header
so the following sequence
export [email protected]
mail -aFrom:[email protected] -s 'Testing'
The result, in my mail clients, is a mail from [email protected], which any replies to will default to [email protected]
NB: Mac OS users: you don't have -a , but you do have $REPLYTO
NB(2): CentOS users, many commenters have added that you need to use -r
not -a
NB(3): This answer is at least ten years old(1), please bear that in mind when you're coming in from Google.
Mongoose and multiple database in single node.js project
A bit optimized(for me atleast) solution. write this to a file db.js and require this to wherever required and call it with a function call and you are good to go.
const MongoClient = require('mongodb').MongoClient;
async function getConnections(url,db){
return new Promise((resolve,reject)=>{
MongoClient.connect(url, { useUnifiedTopology: true },function(err, client) {
if(err) { console.error(err)
resolve(false);
}
else{
resolve(client.db(db));
}
})
});
}
module.exports = async function(){
let dbs = [];
dbs['db1'] = await getConnections('mongodb://localhost:27017/','db1');
dbs['db2'] = await getConnections('mongodb://localhost:27017/','db2');
return dbs;
};
How to print without newline or space?
Using functools.partial to create a new function called printf
>>> import functools
>>> printf = functools.partial(print, end="")
>>> printf("Hello world\n")
Hello world
Easy way to wrap a function with default parameters.
How do I use CMake?
I don't know about Windows (never used it), but on a Linux system you just have to create a build directory (in the top source directory)
mkdir build-dir
go inside it
cd build-dir
then run cmake
and point to the parent directory
cmake ..
and finally run make
make
Notice that make
and cmake
are different programs. cmake
is a Makefile
generator, and the make
utility is governed by a Makefile
textual file. See cmake & make wikipedia pages.
NB: On Windows, cmake
might operate so could need to be used differently. You'll need to read the documentation (like I did for Linux)
Text to speech(TTS)-Android
// variable declaration
TextToSpeech tts;
// TextToSpeech initialization, must go within the onCreate method
tts = new TextToSpeech(getActivity(), new TextToSpeech.OnInitListener() {
@Override
public void onInit(int i) {
if (i == TextToSpeech.SUCCESS) {
int result = tts.setLanguage(Locale.US);
if (result == TextToSpeech.LANG_MISSING_DATA ||
result == TextToSpeech.LANG_NOT_SUPPORTED) {
Log.e("TTS", "Lenguage not supported");
}
} else {
Log.e("TTS", "Initialization failed");
}
}
});
// method call
public void buttonSpeak().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
speak();
}
});
}
private void speak() {
tts.speak("Text to Speech Test", TextToSpeech.QUEUE_ADD, null);
}
@Override
public void onDestroy() {
if (tts != null) {
tts.stop();
tts.shutdown();
}
super.onDestroy();
}
taken from: Text to Speech Youtube Tutorial
How to copy files between two nodes using ansible
If you want to do rsync and use custom user and custom ssh key, you need to write this key in rsync options.
---
- name: rsync
hosts: serverA,serverB,serverC,serverD,serverE,serverF
gather_facts: no
vars:
ansible_user: oracle
ansible_ssh_private_key_file: ./mykey
src_file: "/path/to/file.txt"
tasks:
- name: Copy Remote-To-Remote from serverA to server{B..F}
synchronize:
src: "{{ src_file }}"
dest: "{{ src_file }}"
rsync_opts:
- "-e ssh -i /remote/path/to/mykey"
delegate_to: serverA
Count character occurrences in a string in C++
Try
#include <iostream>
#include <string>
using namespace std;
int WordOccurrenceCount( std::string const & str, std::string const & word )
{
int count(0);
std::string::size_type word_pos( 0 );
while ( word_pos!=std::string::npos )
{
word_pos = str.find(word, word_pos );
if ( word_pos != std::string::npos )
{
++count;
// start next search after this word
word_pos += word.length();
}
}
return count;
}
int main()
{
string sting1="theeee peeeearl is in theeee riveeeer";
string word1="e";
cout<<word1<<" occurs "<<WordOccurrenceCount(sting1,word1)<<" times in ["<<sting1 <<"] \n\n";
return 0;
}
How to convert a std::string to const char* or char*?
Use the .c_str()
method for const char *
.
You can use &mystring[0]
to get a char *
pointer, but there are a couple of gotcha's: you won't necessarily get a zero terminated string, and you won't be able to change the string's size. You especially have to be careful not to add characters past the end of the string or you'll get a buffer overrun (and probable crash).
There was no guarantee that all of the characters would be part of the same contiguous buffer until C++11, but in practice all known implementations of std::string
worked that way anyway; see Does “&s[0]” point to contiguous characters in a std::string?.
Note that many string
member functions will reallocate the internal buffer and invalidate any pointers you might have saved. Best to use them immediately and then discard.
HTML Script tag: type or language (or omit both)?
HTML4/XHTML1 requires
<script type="...">...</script>
HTML5 faces the fact that there is only one scripting language on the web, and allows
<script>...</script>
The latter works in any browser that supports scripting (NN2+).
How to stash my previous commit?
If you've not pushed either commit to your remote repository, you could use interactive rebasing to 'reorder' your commits and stash the (new) most recent commit's changes only.
Assuming you have the tip of your current branch (commit 111 in your example) checked out, execute the following:
git rebase -i HEAD~2
This will open your default editor, listing most recent 2 commits and provide you with some instructions. Be very cautious as to what you do here, as you are going to effectively 'rewrite' the history of your repository, and can potentially lose work if you aren't careful (make a backup of the whole repository first if necessary). I've estimated commit hashes/titles below for example
pick 222 commit to be stashed
pick 111 commit to be pushed to remote
# Rebase 111..222 onto 333
#
# Commands:
# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.
#
# However, if you remove everything, the rebase will be aborted.
#
# Note that empty commits are commented out
Reorder the two commits (they are listed oldest => newest) like this:
pick 111 commit to be pushed to remote
pick 222 commit to be stashed
Save and exit, at which point git will do some processing to rewrite the two commits you have changed. Assuming no issues, you should have reversed the order of your two changesets. This can be confirmed with git log --oneline -5
which will output newest-first.
At this point, you can simply do a soft-reset on the most recent commit, and stash your working changes:
git reset --soft HEAD~1
git stash
It's important to mention that this option is only really viable if you have not previously pushed any of these changes to your remote, otherwise it can cause issues for everyone using the repository.
JavaScript: SyntaxError: missing ) after argument list
You have an extra closing }
in your function.
var nav = document.getElementsByClassName('nav-coll');
for (var i = 0; i < button.length; i++) {
nav[i].addEventListener('click',function(){
console.log('haha');
} // <== remove this brace
}, false);
};
You really should be using something like JSHint or JSLint to help find these things. These tools integrate with many editors and IDEs, or you can just paste a code fragment into the above web sites and ask for an analysis.
Git diff -w ignore whitespace only at start & end of lines
This is an old question, but is still regularly viewed/needed. I want to post to caution readers like me that whitespace as mentioned in the OP's question is not the same as Regex's definition, to include newlines, tabs, and space characters -- Git asks you to be explicit. See some options here: https://git-scm.com/book/en/v2/Customizing-Git-Git-Configuration
As stated, git diff -b
or git diff --ignore-space-change
will ignore spaces at line ends. If you desire that setting to be your default behavior, the following line adds that intent to your .gitconfig file, so it will always ignore the space at line ends:
git config --global core.whitespace trailing-space
In my case, I found this question because I was interested in ignoring "carriage return whitespace differences", so I needed this:
git diff --ignore-cr-at-eol
or
git config --global core.whitespace cr-at-eol
from here.
You can also make it the default only for that repo by omitting the --global parameter, and checking in the settings file for that repo. For the CR problem I faced, it goes away after check-in if warncrlf or autocrlf = true in the [core] section of the .gitconfig file.