pip install failing with: OSError: [Errno 13] Permission denied on directory
We should really stop advising the use of sudo with pip install. It's better to first try pip install --user. If this fails then take a look at the top post here.
The reason you shouldn't use sudo is as follows:
When you run pip with sudo, you are running arbitrary Python code from the Internet as a root user, which is quite a big security risk. If someone puts up a malicious project on PyPI and you install it, you give an attacker root access to your machine.
ln (Natural Log) in Python
Here is the correct implementation using numpy (np.log() is the natural logarithm)
import numpy as np
p = 100
r = 0.06 / 12
FV = 4000
n = np.log(1 + FV * r/ p) / np.log(1 + r)
print ("Number of periods = " + str(n))
Output:
Number of periods = 36.55539635919235
npm install Error: rollbackFailedOptional
I had the same effect creating a react app with PhpStorm. And then at the end it just says done. Running the same command in the terminal gave me detailed errors. The project folder I've created was named react which seems to be a no-go.
Make sure your project folder is not named react.
Best way to convert string to bytes in Python 3?
Answer for a slightly different problem:
You have a sequence of raw unicode that was saved into a str variable:
s_str: str = "\x00\x01\x00\xc0\x01\x00\x00\x00\x04"
You need to be able to get the byte literal of that unicode (for struct.unpack(), etc.)
s_bytes: bytes = b'\x00\x01\x00\xc0\x01\x00\x00\x00\x04'
Solution:
s_new: bytes = bytes(s, encoding="raw_unicode_escape")
Reference (scroll up for standard encodings):
websocket closing connection automatically
This worked for me while the other solutions were not!
- Update your jupyters
- Start your jupyters via your preferred notebook or lab but add this code at the end of the line in the console: <--no-browser>
This is stopping to need to be connected to your EC2 instance all the time. Therefore even if you loose connection due to internet connection loss, whenever you gain a new wifi access it automatically re-connects to the actively working kernel.
Also, don't forget to start your jupyter in a tmux account or a ngnix or other environments like that.
Hope this helps!
Mock MVC - Add Request Parameter to test
When i analyzed your code. I have also faced the same problem but my problem is if i give value for both first and last name means it is working fine. but when i give only one value means it says 400. anyway use the .andDo(print()) method to find out the error
public void testGetUserByName() throws Exception {
String firstName = "Jack";
String lastName = "s";
this.userClientObject = client.createClient();
mockMvc.perform(get("/byName")
.sessionAttr("userClientObject", this.userClientObject)
.param("firstName", firstName)
.param("lastName", lastName)
).andDo(print())
.andExpect(status().isOk())
.andExpect(content().contentType("application/json"))
.andExpect(jsonPath("$[0].id").exists())
.andExpect(jsonPath("$[0].fn").value("Marge"));
}
If your problem is org.springframework.web.bind.missingservletrequestparameterexception you have to change your code to
@RequestMapping(value = "/byName", method = RequestMethod.GET)
@ResponseStatus(HttpStatus.OK)
public
@ResponseBody
String getUserByName(
@RequestParam( value="firstName",required = false) String firstName,
@RequestParam(value="lastName",required = false) String lastName,
@ModelAttribute("userClientObject") UserClient userClient)
{
return client.getUserByName(userClient, firstName, lastName);
}
How do you use variables in a simple PostgreSQL script?
Building on @nad2000's answer and @Pavel's answer here, this is where I ended up for my Flyway migration scripts. Handling for scenarios where the database schema was manually modified.
DO $$
BEGIN
IF NOT EXISTS(
SELECT TRUE FROM pg_attribute
WHERE attrelid = (
SELECT c.oid
FROM pg_class c
JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE
n.nspname = CURRENT_SCHEMA()
AND c.relname = 'device_ip_lookups'
)
AND attname = 'active_date'
AND NOT attisdropped
AND attnum > 0
)
THEN
RAISE NOTICE 'ADDING COLUMN';
ALTER TABLE device_ip_lookups
ADD COLUMN active_date TIMESTAMP;
ELSE
RAISE NOTICE 'SKIPPING, COLUMN ALREADY EXISTS';
END IF;
END $$;
Why use multiple columns as primary keys (composite primary key)
Another example of compound primary keys are the usage of Association tables. Suppose you have a person table that contains a set of people and a group table that contains a set of groups. Now you want to create a many to many relationship on person and group. Meaning each person can belong to many groups. Here is what the table structure would look like using a compound primary key.
Create Table Person(
PersonID int Not Null,
FirstName varchar(50),
LastName varchar(50),
Constraint PK_Person PRIMARY KEY (PersonID))
Create Table Group (
GroupId int Not Null,
GroupName varchar(50),
Constraint PK_Group PRIMARY KEY (GroupId))
Create Table GroupMember (
GroupId int Not Null,
PersonId int Not Null,
CONSTRAINT FK_GroupMember_Group FOREIGN KEY (GroupId) References Group(GroupId),
CONSTRAINT FK_GroupMember_Person FOREIGN KEY (PersonId) References Person(PersonId),
CONSTRAINT PK_GroupMember PRIMARY KEY (GroupId, PersonID))
Is an HTTPS query string secure?
Yes, from the moment on you establish a HTTPS connection everyting is secure. The query string (GET) as the POST is sent over SSL.
how do I use an enum value on a switch statement in C++
You can use a std::map to map the input to your enum:
#include <iostream>
#include <string>
#include <map>
using namespace std;
enum level {easy, medium, hard};
map<string, level> levels;
void register_levels()
{
levels["easy"] = easy;
levels["medium"] = medium;
levels["hard"] = hard;
}
int main()
{
register_levels();
string input;
cin >> input;
switch( levels[input] )
{
case easy:
cout << "easy!"; break;
case medium:
cout << "medium!"; break;
case hard:
cout << "hard!"; break;
}
}
What is the Angular equivalent to an AngularJS $watch?
Here is another approach using getter and setter functions for the model.
@Component({
selector: 'input-language',
template: `
…
<input
type="text"
placeholder="Language"
[(ngModel)]="query"
/>
`,
})
export class InputLanguageComponent {
set query(value) {
this._query = value;
console.log('query set to :', value)
}
get query() {
return this._query;
}
}
how to check for null with a ng-if values in a view with angularjs?
You should check for !test, here is a fiddle showing that.
<span ng-if="!test">null</span>
create unique id with javascript
could you not just keep a running index?
var _selectIndex = 0;
...code...
var newSelectBox = document.createElement("select");
newSelectBox.setAttribute("id","select-"+_selectIndex++);
EDIT
Upon further consideration, you may actually prefer to use array-style names for your selects...
e.g.
<select name="city[]"><option ..../></select>
<select name="city[]"><option ..../></select>
<select name="city[]"><option ..../></select>
then, on the server side in php for example:
$cities = $_POST['city']; //array of option values from selects
EDIT 2 In response to OP comment
Dynamically creating options using DOM methods can be done as follows:
var newSelectBox = document.createElement("select");
newSelectBox.setAttribute("id","select-"+_selectIndex++);
var city = null,city_opt=null;
for (var i=0, len=cities.length; i< len; i++) {
city = cities[i];
var city_opt = document.createElement("option");
city_opt.setAttribute("value",city);
city_opt.appendChild(document.createTextNode(city));
newSelectBox.appendChild(city_opt);
}
document.getElementById("example_element").appendChild(newSelectBox);
assuming that the cities array already exists
Alternatively you could use the innerHTML method.....
var newSelectBox = document.createElement("select");
newSelectBox.setAttribute("id","select-"+_selectIndex++);
document.getElementById("example_element").appendChild(newSelectBox);
var city = null,htmlStr="";
for (var i=0, len=cities.length; i< len; i++) {
city = cities[i];
htmlStr += "<option value='" + city + "'>" + city + "</option>";
}
newSelectBox.innerHTML = htmlStr;
Escape double quote in VB string
Escaping quotes in VB6 or VBScript strings is simple in theory although often frightening when viewed. You escape a double quote with another double quote.
An example:
"c:\program files\my app\app.exe"
If I want to escape the double quotes so I could pass this to the shell execute function listed by Joe or the VB6 Shell function I would write it:
escapedString = """c:\program files\my app\app.exe"""
How does this work? The first and last quotes wrap the string and let VB know this is a string. Then each quote that is displayed literally in the string has another double quote added in front of it to escape it.
It gets crazier when you are trying to pass a string with multiple quoted sections. Remember, every quote you want to pass has to be escaped.
If I want to pass these two quoted phrases as a single string separated by a space (which is not uncommon):
"c:\program files\my app\app.exe" "c:\documents and settings\steve"
I would enter this:
escapedQuoteHell = """c:\program files\my app\app.exe"" ""c:\documents and settings\steve"""
I've helped my sysadmins with some VBScripts that have had even more quotes.
It's not pretty, but that's how it works.
How to expand a list to function arguments in Python
You should use the * operator, like foo(*values) Read the Python doc unpackaging argument lists.
Also, do read this: http://www.saltycrane.com/blog/2008/01/how-to-use-args-and-kwargs-in-python/
def foo(x,y,z):
return "%d, %d, %d" % (x,y,z)
values = [1,2,3]
# the solution.
foo(*values)
json.decoder.JSONDecodeError: Extra data: line 2 column 1 (char 190)
This error can also show up if there are parts in your string that json.loads() does not recognize. An in this example string, an error will be raised at character 27 (char 27).
string = """[{"Item1": "One", "Item2": False}, {"Item3": "Three"}]"""
My solution to this would be to use the string.replace() to convert these items to a string:
import json
string = """[{"Item1": "One", "Item2": False}, {"Item3": "Three"}]"""
string = string.replace("False", '"False"')
dict_list = json.loads(string)
Select SQL Server database size
You can check how this query works following this link.
IF OBJECT_ID('tempdb..#spacetable') IS NOT NULL
DROP TABLE tempdb..#spacetable
create table #spacetable
(
database_name varchar(50) ,
total_size_data int,
space_util_data int,
space_data_left int,
percent_fill_data float,
total_size_data_log int,
space_util_log int,
space_log_left int,
percent_fill_log char(50),
[total db size] int,
[total size used] int,
[total size left] int
)
insert into #spacetable
EXECUTE master.sys.sp_MSforeachdb 'USE [?];
select x.[DATABASE NAME],x.[total size data],x.[space util],x.[total size data]-x.[space util] [space left data],
x.[percent fill],y.[total size log],y.[space util],
y.[total size log]-y.[space util] [space left log],y.[percent fill],
y.[total size log]+x.[total size data] ''total db size''
,x.[space util]+y.[space util] ''total size used'',
(y.[total size log]+x.[total size data])-(y.[space util]+x.[space util]) ''total size left''
from (select DB_NAME() ''DATABASE NAME'',
sum(size*8/1024) ''total size data'',sum(FILEPROPERTY(name,''SpaceUsed'')*8/1024) ''space util''
,case when sum(size*8/1024)=0 then ''divide by zero'' else
substring(cast((sum(FILEPROPERTY(name,''SpaceUsed''))*1.0*100/sum(size)) as CHAR(50)),1,6) end ''percent fill''
from sys.master_files where database_id=DB_ID(DB_NAME()) and type=0
group by type_desc ) as x ,
(select
sum(size*8/1024) ''total size log'',sum(FILEPROPERTY(name,''SpaceUsed'')*8/1024) ''space util''
,case when sum(size*8/1024)=0 then ''divide by zero'' else
substring(cast((sum(FILEPROPERTY(name,''SpaceUsed''))*1.0*100/sum(size)) as CHAR(50)),1,6) end ''percent fill''
from sys.master_files where database_id=DB_ID(DB_NAME()) and type=1
group by type_desc )y'
select * from #spacetable
order by database_name
drop table #spacetable
How to delete/unset the properties of a javascript object?
To blank it:
myObject["myVar"]=null;
To remove it:
delete myObject["myVar"]
as you can see in duplicate answers
Getting the document object of an iframe
Try the following
var doc=document.getElementById("frame").contentDocument;
// Earlier versions of IE or IE8+ where !DOCTYPE is not specified
var doc=document.getElementById("frame").contentWindow.document;
Note: AndyE pointed out that contentWindow is supported by all major browsers so this may be the best way to go.
Note2: In this sample you won't be able to access the document via any means. The reason is you can't access the document of an iframe with a different origin because it violates the "Same Origin" security policy
CSS center content inside div
You just do CSS changes for parent div
.parent-div {
text-align: center;
display: block;
}
pg_config executable not found
On alpine, the library containing pg_config is postgresql-dev. To install, run:
apk add postgresql-dev
How to set a DateTime variable in SQL Server 2008?
You need to enclose the date time value in quotes:
DECLARE @Test AS DATETIME
SET @Test = '2011-02-15'
PRINT @Test
What throws an IOException in Java?
Assume you were:
- Reading a network file and got disconnected.
- Reading a local file that was no longer available.
- Using some stream to read data and some other process closed the stream.
- Trying to read/write a file, but don't have permission.
- Trying to write to a file, but disk space was no longer available.
There are many more examples, but these are the most common, in my experience.
keytool error Keystore was tampered with, or password was incorrect
For me I solved it by changing passwords from Arabic letter to English letter, but first I went to the folder and deleted the generated key then it works.
Math constant PI value in C
Just define:
#define M_PI acos(-1.0)
It should give you exact PI number that math functions are working with. So if they change PI value they are working with in tangent or cosine or sine, then your program should be always up-to-dated ;)
How to update each dependency in package.json to the latest version?
The very easiest way to do this as of today is use pnpm rather than npm and simply type:
pnpm update --latest
Adding parameter to ng-click function inside ng-repeat doesn't seem to work
Also worth noting, for people who find this in their searches, is this...
<div ng-repeat="button in buttons" class="bb-button" ng-click="goTo(button.path)">
<div class="bb-button-label">{{ button.label }}</div>
<div class="bb-button-description">{{ button.description }}</div>
</div>
Note the value of ng-click. The parameter passed to goTo() is a string from a property of the binding object (the button), but it is not wrapped in quotes. Looks like AngularJS handles that for us. I got hung up on that for a few minutes.
Array.Add vs +=
If you want a dynamically sized array, then you should make a list. Not only will you get the .Add() functionality, but as @frode-f explains, dynamic arrays are more memory efficient and a better practice anyway.
And it's so easy to use.
Instead of your array declaration, try this:
$outItems = New-Object System.Collections.Generic.List[System.Object]
Adding items is simple.
$outItems.Add(1)
$outItems.Add("hi")
And if you really want an array when you're done, there's a function for that too.
$outItems.ToArray()
What is the backslash character (\\)?
\ is used for escape sequences in programming languages.
\n prints a newline
\\ prints a backslash
\" prints "
\t prints a tabulator
\b moves the cursor one back
Work with a time span in Javascript
Here a .NET C# similar implementation of a timespan class that supports days, hours, minutes and seconds. This implementation also supports negative timespans.
const MILLIS_PER_SECOND = 1000;
const MILLIS_PER_MINUTE = MILLIS_PER_SECOND * 60; // 60,000
const MILLIS_PER_HOUR = MILLIS_PER_MINUTE * 60; // 3,600,000
const MILLIS_PER_DAY = MILLIS_PER_HOUR * 24; // 86,400,000
export class TimeSpan {
private _millis: number;
private static interval(value: number, scale: number): TimeSpan {
if (Number.isNaN(value)) {
throw new Error("value can't be NaN");
}
const tmp = value * scale;
const millis = TimeSpan.round(tmp + (value >= 0 ? 0.5 : -0.5));
if ((millis > TimeSpan.maxValue.totalMilliseconds) || (millis < TimeSpan.minValue.totalMilliseconds)) {
throw new TimeSpanOverflowError("TimeSpanTooLong");
}
return new TimeSpan(millis);
}
private static round(n: number): number {
if (n < 0) {
return Math.ceil(n);
} else if (n > 0) {
return Math.floor(n);
}
return 0;
}
private static timeToMilliseconds(hour: number, minute: number, second: number): number {
const totalSeconds = (hour * 3600) + (minute * 60) + second;
if (totalSeconds > TimeSpan.maxValue.totalSeconds || totalSeconds < TimeSpan.minValue.totalSeconds) {
throw new TimeSpanOverflowError("TimeSpanTooLong");
}
return totalSeconds * MILLIS_PER_SECOND;
}
public static get zero(): TimeSpan {
return new TimeSpan(0);
}
public static get maxValue(): TimeSpan {
return new TimeSpan(Number.MAX_SAFE_INTEGER);
}
public static get minValue(): TimeSpan {
return new TimeSpan(Number.MIN_SAFE_INTEGER);
}
public static fromDays(value: number): TimeSpan {
return TimeSpan.interval(value, MILLIS_PER_DAY);
}
public static fromHours(value: number): TimeSpan {
return TimeSpan.interval(value, MILLIS_PER_HOUR);
}
public static fromMilliseconds(value: number): TimeSpan {
return TimeSpan.interval(value, 1);
}
public static fromMinutes(value: number): TimeSpan {
return TimeSpan.interval(value, MILLIS_PER_MINUTE);
}
public static fromSeconds(value: number): TimeSpan {
return TimeSpan.interval(value, MILLIS_PER_SECOND);
}
public static fromTime(hours: number, minutes: number, seconds: number): TimeSpan;
public static fromTime(days: number, hours: number, minutes: number, seconds: number, milliseconds: number): TimeSpan;
public static fromTime(daysOrHours: number, hoursOrMinutes: number, minutesOrSeconds: number, seconds?: number, milliseconds?: number): TimeSpan {
if (milliseconds != undefined) {
return this.fromTimeStartingFromDays(daysOrHours, hoursOrMinutes, minutesOrSeconds, seconds, milliseconds);
} else {
return this.fromTimeStartingFromHours(daysOrHours, hoursOrMinutes, minutesOrSeconds);
}
}
private static fromTimeStartingFromHours(hours: number, minutes: number, seconds: number): TimeSpan {
const millis = TimeSpan.timeToMilliseconds(hours, minutes, seconds);
return new TimeSpan(millis);
}
private static fromTimeStartingFromDays(days: number, hours: number, minutes: number, seconds: number, milliseconds: number): TimeSpan {
const totalMilliSeconds = (days * MILLIS_PER_DAY) +
(hours * MILLIS_PER_HOUR) +
(minutes * MILLIS_PER_MINUTE) +
(seconds * MILLIS_PER_SECOND) +
milliseconds;
if (totalMilliSeconds > TimeSpan.maxValue.totalMilliseconds || totalMilliSeconds < TimeSpan.minValue.totalMilliseconds) {
throw new TimeSpanOverflowError("TimeSpanTooLong");
}
return new TimeSpan(totalMilliSeconds);
}
constructor(millis: number) {
this._millis = millis;
}
public get days(): number {
return TimeSpan.round(this._millis / MILLIS_PER_DAY);
}
public get hours(): number {
return TimeSpan.round((this._millis / MILLIS_PER_HOUR) % 24);
}
public get minutes(): number {
return TimeSpan.round((this._millis / MILLIS_PER_MINUTE) % 60);
}
public get seconds(): number {
return TimeSpan.round((this._millis / MILLIS_PER_SECOND) % 60);
}
public get milliseconds(): number {
return TimeSpan.round(this._millis % 1000);
}
public get totalDays(): number {
return this._millis / MILLIS_PER_DAY;
}
public get totalHours(): number {
return this._millis / MILLIS_PER_HOUR;
}
public get totalMinutes(): number {
return this._millis / MILLIS_PER_MINUTE;
}
public get totalSeconds(): number {
return this._millis / MILLIS_PER_SECOND;
}
public get totalMilliseconds(): number {
return this._millis;
}
public add(ts: TimeSpan): TimeSpan {
const result = this._millis + ts.totalMilliseconds;
return new TimeSpan(result);
}
public subtract(ts: TimeSpan): TimeSpan {
const result = this._millis - ts.totalMilliseconds;
return new TimeSpan(result);
}
}
How to use
Create a new TimeSpan object
From zero
const ts = TimeSpan.zero;
const milliseconds = 10000; // 1 second
// by using the constructor
const ts1 = new TimeSpan(milliseconds);
// or as an alternative you can use the static factory method
const ts2 = TimeSpan.fromMilliseconds(milliseconds);
const seconds = 86400; // 1 day
const ts = TimeSpan.fromSeconds(seconds);
const minutes = 1440; // 1 day
const ts = TimeSpan.fromMinutes(minutes);
const hours = 24; // 1 day
const ts = TimeSpan.fromHours(hours);
const days = 1; // 1 day
const ts = TimeSpan.fromDays(days);
const hours = 1;
const minutes = 1;
const seconds = 1;
const ts = TimeSpan.fromTime(hours, minutes, seconds);
const days = 1;
const hours = 1;
const minutes = 1;
const seconds = 1;
const milliseconds = 1;
const ts = TimeSpan.fromTime(days, hours, minutes, seconds, milliseconds);
const ts = TimeSpan.maxValue;
const ts = TimeSpan.minValue;
const ts = TimeSpan.minValue;
const ts1 = TimeSpan.fromDays(1);
const ts2 = TimeSpan.fromHours(1);
const ts = ts1.add(ts2);
console.log(ts.days); // 1
console.log(ts.hours); // 1
console.log(ts.minutes); // 0
console.log(ts.seconds); // 0
console.log(ts.milliseconds); // 0
const ts1 = TimeSpan.fromDays(1);
const ts2 = TimeSpan.fromHours(1);
const ts = ts1.subtract(ts2);
console.log(ts.days); // 0
console.log(ts.hours); // 23
console.log(ts.minutes); // 0
console.log(ts.seconds); // 0
console.log(ts.milliseconds); // 0
const days = 1;
const hours = 1;
const minutes = 1;
const seconds = 1;
const milliseconds = 1;
const ts = TimeSpan.fromTime2(days, hours, minutes, seconds, milliseconds);
console.log(ts.days); // 1
console.log(ts.hours); // 1
console.log(ts.minutes); // 1
console.log(ts.seconds); // 1
console.log(ts.milliseconds); // 1
console.log(ts.totalDays) // 1.0423726967592593;
console.log(ts.totalHours) // 25.016944722222224;
console.log(ts.totalMinutes) // 1501.0166833333333;
console.log(ts.totalSeconds) // 90061.001;
console.log(ts.totalMilliseconds); // 90061001;
See also here: https://github.com/erdas/timespan
How do I write a for loop in bash
Bash 3.0+ can use this syntax:
for i in {1..10} ; do ... ; done
..which avoids spawning an external program to expand the sequence (such as seq 1 10).
Of course, this has the same problem as the for(()) solution, being tied to bash and even a particular version (if this matters to you).
convert HTML ( having Javascript ) to PDF using JavaScript
With Docmosis or JODReports you could feed your HTML and Javascript to the document render process which could produce PDF or doc or other formats. The conversion underneath is performed by OpenOffice so results will be dependent on the OpenOffice import filters. You can try manually by saving your web page to a file, then loading with OpenOffice - if that looks good enough, then these tools will be able to give you the same result as a PDF.
How to calculate distance between two locations using their longitude and latitude value
private String getDistanceOnRoad(double latitude, double longitude,
double prelatitute, double prelongitude) {
String result_in_kms = "";
String url = "http://maps.google.com/maps/api/directions/xml?origin="
+ latitude + "," + longitude + "&destination=" + prelatitute
+ "," + prelongitude + "&sensor=false&units=metric";
String tag[] = { "text" };
HttpResponse response = null;
try {
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpPost httpPost = new HttpPost(url);
response = httpClient.execute(httpPost, localContext);
InputStream is = response.getEntity().getContent();
DocumentBuilder builder = DocumentBuilderFactory.newInstance()
.newDocumentBuilder();
Document doc = builder.parse(is);
if (doc != null) {
NodeList nl;
ArrayList args = new ArrayList();
for (String s : tag) {
nl = doc.getElementsByTagName(s);
if (nl.getLength() > 0) {
Node node = nl.item(nl.getLength() - 1);
args.add(node.getTextContent());
} else {
args.add(" - ");
}
}
result_in_kms = String.format("%s", args.get(0));
}
} catch (Exception e) {
e.printStackTrace();
}
return result_in_kms;
}
nodeJS - How to create and read session with express
Hello I am trying to add new session values in node js like
req.session.portal = false
Passport.authenticate('facebook', (req, res, next) => {
next()
})(req, res, next)
On passport strategies I am not getting portal value in mozilla request but working fine with chrome and opera
FacebookStrategy: new PassportFacebook.Strategy({
clientID: Configuration.SocialChannel.Facebook.AppId,
clientSecret: Configuration.SocialChannel.Facebook.AppSecret,
callbackURL: Configuration.SocialChannel.Facebook.CallbackURL,
profileFields: Configuration.SocialChannel.Facebook.Fields,
scope: Configuration.SocialChannel.Facebook.Scope,
passReqToCallback: true
}, (req, accessToken, refreshToken, profile, done) => {
console.log(JSON.stringify(req.session));
How do I get the number of elements in a list?
Besides len you can also use operator.length_hint (requires Python 3.4+). For a normal list both are equivalent, but length_hint makes it possible to get the length of a list-iterator, which could be useful in certain circumstances:
>>> from operator import length_hint
>>> l = ["apple", "orange", "banana"]
>>> len(l)
3
>>> length_hint(l)
3
>>> list_iterator = iter(l)
>>> len(list_iterator)
TypeError: object of type 'list_iterator' has no len()
>>> length_hint(list_iterator)
3
But length_hint is by definition only a "hint", so most of the time len is better.
I've seen several answers suggesting accessing __len__. This is all right when dealing with built-in classes like list, but it could lead to problems with custom classes, because len (and length_hint) implement some safety checks. For example, both do not allow negative lengths or lengths that exceed a certain value (the sys.maxsize value). So it's always safer to use the len function instead of the __len__ method!
Twitter Bootstrap Datepicker within modal window
Add z-indez in class ui-datepicker
<style>
.ui-datepicker{ z-index:1151 !important; }
</style>
Table variable error: Must declare the scalar variable "@temp"
You should use hash (#) tables, That you actually looking for because variables value will remain till that execution only. e.g. -
declare @TEMP table (ID int, Name varchar(max))
insert into @temp SELECT ID, Name FROM Table
When above two and below two statements execute separately.
SELECT * FROM @TEMP
WHERE @TEMP.ID = 1
The error will show because the value of variable lost when you execute the batch of query second time. It definitely gives o/p when you run an entire block of code.
The hash table is the best possible option for storing and retrieving the temporary value. It last long till the parent session is alive.
How to inspect FormData?
In certain cases, the use of :
for(var pair of formData.entries(){...
is impossible.
I've used this code in replacement :
var outputLog = {}, iterator = myFormData.entries(), end = false;
while(end == false) {
var item = iterator.next();
if(item.value!=undefined) {
outputLog[item.value[0]] = item.value[1];
} else if(item.done==true) {
end = true;
}
}
console.log(outputLog);
It's not a very smart code, but it works...
Hope it's help.
How to start an application without waiting in a batch file?
I'm making a guess here, but your start invocation probably looks like this:
start "\Foo\Bar\Path with spaces in it\program.exe"
This will open a new console window, using “\Foo\Bar\Path with spaces in it\program.exe” as its title.
If you use start with something that is (or needs to be) surrounded by quotes, you need to put empty quotes as the first argument:
start "" "\Foo\Bar\Path with spaces in it\program.exe"
This is because start interprets the first quoted argument it finds as the window title for a new console window.
counting number of directories in a specific directory
A pure bash solution:
shopt -s nullglob
dirs=( /path/to/directory/*/ )
echo "There are ${#dirs[@]} (non-hidden) directories"
If you also want to count the hidden directories:
shopt -s nullglob dotglob
dirs=( /path/to/directory/*/ )
echo "There are ${#dirs[@]} directories (including hidden ones)"
Note that this will also count links to directories. If you don't want that, it's a bit more difficult with this method.
Using find:
find /path/to/directory -type d \! -name . -prune -exec printf x \; | wc -c
The trick is to output an x to stdout each time a directory is found, and then use wc to count the number of characters. This will count the number of all directories (including hidden ones), excluding links.
The methods presented here are all safe wrt to funny characters that can appear in file names (spaces, newlines, glob characters, etc.).
$_SERVER["REMOTE_ADDR"] gives server IP rather than visitor IP
Replacing:
$_SERVER["REMOTE_ADDR"];
With:
$_SERVER["HTTP_X_REAL_IP"];
Worked for me.
Open an html page in default browser with VBA?
If you want a more robust solution with ShellExecute that will open ANY file, folder or URL using the default OS associated program to do so, here is a function taken from http://access.mvps.org/access/api/api0018.htm:
'************ Code Start **********
' This code was originally written by Dev Ashish.
' It is not to be altered or distributed,
' except as part of an application.
' You are free to use it in any application,
' provided the copyright notice is left unchanged.
'
' Code Courtesy of
' Dev Ashish
'
Private Declare Function apiShellExecute Lib "shell32.dll" _
Alias "ShellExecuteA" _
(ByVal hwnd As Long, _
ByVal lpOperation As String, _
ByVal lpFile As String, _
ByVal lpParameters As String, _
ByVal lpDirectory As String, _
ByVal nShowCmd As Long) _
As Long
'***App Window Constants***
Public Const WIN_NORMAL = 1 'Open Normal
Public Const WIN_MAX = 3 'Open Maximized
Public Const WIN_MIN = 2 'Open Minimized
'***Error Codes***
Private Const ERROR_SUCCESS = 32&
Private Const ERROR_NO_ASSOC = 31&
Private Const ERROR_OUT_OF_MEM = 0&
Private Const ERROR_FILE_NOT_FOUND = 2&
Private Const ERROR_PATH_NOT_FOUND = 3&
Private Const ERROR_BAD_FORMAT = 11&
'***************Usage Examples***********************
'Open a folder: ?fHandleFile("C:\TEMP\",WIN_NORMAL)
'Call Email app: ?fHandleFile("mailto:[email protected]",WIN_NORMAL)
'Open URL: ?fHandleFile("http://home.att.net/~dashish", WIN_NORMAL)
'Handle Unknown extensions (call Open With Dialog):
' ?fHandleFile("C:\TEMP\TestThis",Win_Normal)
'Start Access instance:
' ?fHandleFile("I:\mdbs\CodeNStuff.mdb", Win_NORMAL)
'****************************************************
Function fHandleFile(stFile As String, lShowHow As Long)
Dim lRet As Long, varTaskID As Variant
Dim stRet As String
'First try ShellExecute
lRet = apiShellExecute(hWndAccessApp, vbNullString, _
stFile, vbNullString, vbNullString, lShowHow)
If lRet > ERROR_SUCCESS Then
stRet = vbNullString
lRet = -1
Else
Select Case lRet
Case ERROR_NO_ASSOC:
'Try the OpenWith dialog
varTaskID = Shell("rundll32.exe shell32.dll,OpenAs_RunDLL " _
& stFile, WIN_NORMAL)
lRet = (varTaskID <> 0)
Case ERROR_OUT_OF_MEM:
stRet = "Error: Out of Memory/Resources. Couldn't Execute!"
Case ERROR_FILE_NOT_FOUND:
stRet = "Error: File not found. Couldn't Execute!"
Case ERROR_PATH_NOT_FOUND:
stRet = "Error: Path not found. Couldn't Execute!"
Case ERROR_BAD_FORMAT:
stRet = "Error: Bad File Format. Couldn't Execute!"
Case Else:
End Select
End If
fHandleFile = lRet & _
IIf(stRet = "", vbNullString, ", " & stRet)
End Function
'************ Code End **********
Just put this into a separate module and call fHandleFile() with the right parameters.
get basic SQL Server table structure information
Write the table name in the query editor select the name and press Alt+F1 and it will bring all the information of the table.
How to open an Excel file in C#?
open Excel file
System.Diagnostics.Process.Start(@"c:\document.xls");
how to make label visible/invisible?
You can set display attribute as none to hide a label.
<label id="excel-data-div" style="display: none;"></label>
How to set max and min value for Y axis
Just set the value for scaleStartValue in your options.
var options = {
// ....
scaleStartValue: 0,
}
See the documentation for this here.
Import a module from a relative path
You could also add the subdirectory to your Python path so that it imports as a normal script.
import sys
sys.path.insert(0, <path to dirFoo>)
import Bar
How do I parse a URL into hostname and path in javascript?
Just use url.js library (for web and node.js).
https://github.com/websanova/js-url
url: http://example.com?param=test#param=again
url('?param'); // test
url('#param'); // again
url('protocol'); // http
url('port'); // 80
url('domain'); // example.com
url('tld'); // com
etc...
How to convert ActiveRecord results into an array of hashes
May be?
result.map(&:attributes)
If you need symbols keys:
result.map { |r| r.attributes.symbolize_keys }
How can I modify the size of column in a MySQL table?
Have you tried this?
ALTER TABLE <table_name> MODIFY <col_name> VARCHAR(65353);
This will change the col_name's type to VARCHAR(65353)
How to add 10 minutes to my (String) time?
I used the code below to add a certain time interval to the current time.
int interval = 30;
SimpleDateFormat df = new SimpleDateFormat("HH:mm");
Calendar time = Calendar.getInstance();
Log.i("Time ", String.valueOf(df.format(time.getTime())));
time.add(Calendar.MINUTE, interval);
Log.i("New Time ", String.valueOf(df.format(time.getTime())));
How can I pad an integer with zeros on the left?
You can use Google Guava:
Maven:
<dependency>
<artifactId>guava</artifactId>
<groupId>com.google.guava</groupId>
<version>14.0.1</version>
</dependency>
Sample code:
String paddedString1 = Strings.padStart("7", 3, '0'); //"007"
String paddedString2 = Strings.padStart("2020", 3, '0'); //"2020"
Note:
Guava is very useful library, it also provides lots of features which related to Collections, Caches, Functional idioms, Concurrency, Strings, Primitives, Ranges, IO, Hashing, EventBus, etc
Ref: GuavaExplained
How to get array keys in Javascript?
Seems to work.
var widthRange = new Array();
widthRange[46] = { sel:46, min:0, max:52 };
widthRange[66] = { sel:66, min:52, max:70 };
widthRange[90] = { sel:90, min:70, max:94 };
for (var key in widthRange)
{
document.write(widthRange[key].sel + "<br />");
document.write(widthRange[key].min + "<br />");
document.write(widthRange[key].max + "<br />");
}
Playing mp3 song on python
So Far, pydub worked best for me. Modules like playsound will also do the job, But It has only one single feature. pydub has many features like slicing the song(file), Adjusting the volume etc...
It is as simple as slicing the lists in python.
So, When it comes to just playing, It is as shown as below.
from pydub import AudioSegment
from pydub.playback import play
path_to_file = r"Music/Harry Potter Theme Song.mp3"
song = AudioSegment.from_mp3(path_to_file)
play(song)
Could not find a declaration file for module 'module-name'. '/path/to/module-name.js' implicitly has an 'any' type
TypeScript is basically implementing rules and adding types to your code to make it more clear and more accurate due to the lack of constraints in Javascript. TypeScript requires you to describe your data, so that the compiler can check your code and find errors. The compiler will let you know if you are using mismatched types, if you are out of your scope or you try to return a different type.
So, when you are using external libraries and modules with TypeScript, they need to contain files that describe the types in that code. Those files are called type declaration files with an extension d.ts. Most of the declaration types for npm modules are already written and you can include them using npm install @types/module_name (where module_name is the name of the module whose types you wanna include).
However, there are modules that don't have their type definitions and in order to make the error go away and import the module using import * as module_name from 'module-name', create a folder typings in the root of your project, inside create a new folder with your module name and in that folder create a module_name.d.ts file and write declare module 'module_name'. After this just go to your tsconfig.json file and add "typeRoots": [ "../../typings", "../../node_modules/@types"] in the compilerOptions (with the proper relative path to your folders) to let TypeScript know where it can find the types definitions of your libraries and modules and add a new property "exclude": ["../../node_modules", "../../typings"] to the file.
Here is an example of how your tsconfig.json file should look like:
{
"compilerOptions": {
"module": "commonjs",
"noImplicitAny": true,
"sourceMap": true,
"outDir": "../dst/",
"target": "ESNEXT",
"typeRoots": [
"../../typings",
"../../node_modules/@types"
]
},
"lib": [
"es2016"
],
"exclude": [
"../../node_modules",
"../../typings"
]
}
By doing this, the error will go away and you will be able to stick to the latest ES6 and TypeScript rules.
Flatten List in LINQ
With query syntax:
var values =
from inner in outer
from value in inner
select value;
ERROR 1067 (42000): Invalid default value for 'created_at'
In my case, I have a file to import.
So I simply added SET sql_mode = ''; at the beginning of the file and it works!
async await return Task
You need to use the await keyword when use async and your function return type should be generic Here is an example with return value:
public async Task<object> MethodName()
{
return await Task.FromResult<object>(null);
}
Here is an example with no return value:
public async Task MethodName()
{
await Task.CompletedTask;
}
Read these:
TPL: http://msdn.microsoft.com/en-us/library/dd460717(v=vs.110).aspx and Tasks: http://msdn.microsoft.com/en-us/library/system.threading.tasks(v=vs.110).aspx
Async: http://msdn.microsoft.com/en-us/library/hh156513.aspx Await: http://msdn.microsoft.com/en-us/library/hh156528.aspx
When to use dynamic vs. static libraries
If your library is going to be shared among several executables, it often makes sense to make it dynamic to reduce the size of the executables. Otherwise, definitely make it static.
There are several disadvantages of using a dll. There is additional overhead for loading and unloading it. There is also an additional dependency. If you change the dll to make it incompatible with your executalbes, they will stop working. On the other hand, if you change a static library, your compiled executables using the old version will not be affected.
Can RDP clients launch remote applications and not desktops
RDP will not do that natively.
As other answers have said -- you'll need to do some scripting and make policy changes as a kludge to make it hard for RDP logins to run anything but the intended application.
However, as of 2008, Microsoft has released application virtualization technology via Terminal Services that will allow you to do this seamlessly.
Docker error cannot delete docker container, conflict: unable to remove repository reference
There is a difference between docker images and docker containers. Check this SO Question.
In short, a container is a runnable instance of an image. which is why you cannot delete an image if there is a running container from that image. You just need to delete the container first.
docker ps -a # Lists containers (and tells you which images they are spun from)
docker images # Lists images
docker rm <container_id> # Removes a stopped container
docker rm -f <container_id> # Forces the removal of a running container (uses SIGKILL)
docker rmi <image_id> # Removes an image
# Will fail if there is a running instance of that image i.e. container
docker rmi -f <image_id> # Forces removal of image even if it is referenced in multiple repositories,
# i.e. same image id given multiple names/tags
# Will still fail if there is a docker container referencing image
Update for Docker 1.13+ [Since Jan 2017]
In Docker 1.13, we regrouped every command to sit under the logical object it’s interacting with
Basically, above commands could also be rewritten, more clearly, as:
docker container ls -a
docker image ls
docker container rm <container_id>
docker image rm <image_id>
Also, if you want to remove EVERYTHING you could use:
docker system prune -a
WARNING! This will remove:
- all stopped containers
- all networks not used by at least one container
- all unused images
- all build cache
How do I declare a global variable in VBA?
If this function is in a module/class, you could just write them outside of the function, so it has Global Scope. Global Scope means the variable can be accessed by another function in the same module/class (if you use dim as declaration statement, use public if you want the variables can be accessed by all function in all modules) :
Dim iRaw As Integer
Dim iColumn As Integer
Function find_results_idle()
iRaw = 1
iColumn = 1
End Function
Function this_can_access_global()
iRaw = 2
iColumn = 2
End Function
How to initialize a JavaScript Date to a particular time zone
You can specify a time zone offset on new Date(), for example:
new Date('Feb 28 2013 19:00:00 EST')
or
new Date('Feb 28 2013 19:00:00 GMT-0500')
Since Date store UTC time ( i.e. getTime returns in UTC ), javascript will them convert the time into UTC, and when you call things like toString javascript will convert the UTC time into browser's local timezone and return the string in local timezone, i.e. If I'm using UTC+8:
> new Date('Feb 28 2013 19:00:00 GMT-0500').toString()
< "Fri Mar 01 2013 08:00:00 GMT+0800 (CST)"
Also you can use normal getHours/Minute/Second method:
> new Date('Feb 28 2013 19:00:00 GMT-0500').getHours()
< 8
( This 8 means after the time is converted into my local time - UTC+8, the hours number is 8. )
comparing two strings in SQL Server
There is no direct string compare function in SQL Server
CASE
WHEN str1 = str2 THEN 0
WHEN str1 < str2 THEN -1
WHEN str1 > str2 THEN 1
ELSE NULL --one of the strings is NULL so won't compare (added on edit)
END
Notes
- you can wraps this via a UDF using CREATE FUNCTION etc
- you may need NULL handling (in my code above, any NULL will report 1)
- str1 and str2 will be column names or @variables
File upload along with other object in Jersey restful web service
You can access the Image File and data from a form using MULTIPART FORM DATA By using the below code.
@POST
@Path("/UpdateProfile")
@Consumes(value={MediaType.APPLICATION_JSON,MediaType.MULTIPART_FORM_DATA})
@Produces(value={MediaType.APPLICATION_JSON,MediaType.APPLICATION_XML})
public Response updateProfile(
@FormDataParam("file") InputStream fileInputStream,
@FormDataParam("file") FormDataContentDisposition contentDispositionHeader,
@FormDataParam("ProfileInfo") String ProfileInfo,
@FormDataParam("registrationId") String registrationId) {
String filePath= "/filepath/"+contentDispositionHeader.getFileName();
OutputStream outputStream = null;
try {
int read = 0;
byte[] bytes = new byte[1024];
outputStream = new FileOutputStream(new File(filePath));
while ((read = fileInputStream.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}
outputStream.flush();
outputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch(Exception ex) {}
}
}
}
How do I select a sibling element using jQuery?
Here is a link which is useful to learn about select a siblings element in Jquery.
How do I select a sibling element using jQuery
$("selector").nextAll();
$("selector").prev();
you can also find an element using Jquery selector
$("h2").siblings('table').find('tr');
For more information, refer this link next(), nextAll(), prev(), prevAll(), find() and siblings in JQuery
pass post data with window.location.href
it's as simple as this
$.post({url: "som_page.php",
data: { data1: value1, data2: value2 }
).done(function( data ) {
$( "body" ).html(data);
});
});
I had to solve this to make a screen lock of my application where I had to pass sensitive data as user and the url where he was working. Then create a function that executes this code
Async always WaitingForActivation
I overcome this issue with if anybody interested. In myMain method i called my readasync method like
Dispatcher.BeginInvoke(new ThreadStart(() => ReadData()));
Everything is fine for me now.
jQuery removing '-' character from string
If you want to remove all - you can use:
.replace(new RegExp('-', 'g'),"")
Performance differences between ArrayList and LinkedList
In a LinkedList the elements have a reference to the element before and after it. In an ArrayList the data structure is just an array.
A LinkedList needs to iterate over N elements to get the Nth element. An ArrayList only needs to return element N of the backing array.
The backing array needs to either be reallocated for the new size and the array copied over or every element after the deleted element needs to be moved up to fill the empty space. A LinkedList just needs to set the previous reference on the element after the removed to the one before the removed and the next reference on the element before the removed element to the element after the removed element. Longer to explain, but faster to do.
Same reason as deletion here.
Where does PHP's error log reside in XAMPP?
I found it in:
\xampp\php\logs\php_error_log
pandas python how to count the number of records or rows in a dataframe
Simple method to get the records count:
df.count()[0]
Execute action when back bar button of UINavigationController is pressed
Here is the simplest possible Swift 5 solution that doesn't require you to create a custom back button and give up all that UINavigationController left button functionality you get for free.
As Brandon A recommends above, you need need to implement UINavigationControllerDelegate in the view controller you want to interact with before returning to it. A good way is to create an unwind segue that you can perform manually or automatically and reuse the same code from a custom done button or the back button.
First, make your view controller of interest (the one you want to detect returning to) a delegate of the navigation controller in its viewDidLoad:
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.delegate = self
}
Second, add an extension at the bottom of the file that overrides navigationController(willShow:animated:)
extension PickerTableViewController: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController,
willShow viewController: UIViewController,
animated: Bool) {
if let _ = viewController as? EditComicBookViewController {
let selectedItemRow = itemList.firstIndex(of: selectedItemName)
selectedItemIndex = IndexPath(row: selectedItemRow!, section: 0)
if let selectedCell = tableView.cellForRow(at: selectedItemIndex) {
performSegue(withIdentifier: "PickedItem", sender: selectedCell)
}
}
}
}
Since your question included a UITableViewController, I included a way to get the index path of the row the user tapped.
How to explicitly obtain post data in Spring MVC?
Spring MVC runs on top of the Servlet API. So, you can use HttpServletRequest#getParameter() for this:
String value1 = request.getParameter("value1");
String value2 = request.getParameter("value2");
The HttpServletRequest should already be available to you inside Spring MVC as one of the method arguments of the handleRequest() method.
Javascript Array.sort implementation?
The ECMAscript standard does not specify which sort algorithm is to be used. Indeed, different browsers feature different sort algorithms. For example, Mozilla/Firefox's sort() is not stable (in the sorting sense of the word) when sorting a map. IE's sort() is stable.
TensorFlow not found using pip
There are multiple groups of answers to this question. This answer aims to generalize one group of answers:
There may not be a version of TensorFlow that is compatible with your version of Python. This is particularly true if you're using a new release of Python. For example, there may be a delay between the release of a new version of Python and the release of TensorFlow for that version of Python.
In this case, I believe your options are to:
- Upgrade or downgrade to a different version of Python. (Virtual environments are good for this, e.g.
conda install python=3.6) - Select a specific version of tensorflow that is compatible with your version of python, e.g. if you're still using python3.4:
pip install tensorflow==2.0 - Compile TensorFlow from the source code.
- Wait for a new release of TensorFlow which is compatible with your version of Python.
Cannot find pkg-config error
for me, (OSX) the problem was solved doing this:
brew install pkg-config
How to get an object's property's value by property name?
$com1 = new-object PSobject #Task1
$com2 = new-object PSobject #Task1
$com3 = new-object PSobject #Task1
$com1 | add-member noteproperty -name user -value jindpal #Task2
$com1 | add-member noteproperty -name code -value IT01 #Task2
$com1 | add-member scriptmethod ver {[system.Environment]::oSVersion.Version} #Task3
$com2 | add-member noteproperty -name user -value singh #Task2
$com2 | add-member noteproperty -name code -value IT02 #Task2
$com2 | add-member scriptmethod ver {[system.Environment]::oSVersion.Version} #Task3
$com3 | add-member noteproperty -name user -value dhanoa #Task2
$com3 | add-member noteproperty -name code -value IT03 #Task2
$com3 | add-member scriptmethod ver {[system.Environment]::oSVersion.Version} #Task3
$arr += $com1, $com2, $com3 #Task4
write-host "windows version of computer1 is: "$com1.ver() #Task3
write-host "user name of computer1 is: "$com1.user #Task6
write-host "code of computer1 is: "$com1,code #Task5
write-host "windows version of computer2 is: "$com2.ver() #Task3
write-host "user name of computer2 is: "$com2.user #Task6
write-host "windows version of computer3 is: "$com3.ver() #Task3
write-host "user name of computer3 is: "$com1.user #Task6
write-host "code of computer3 is: "$com3,code #Task5
read-host
The term "Add-Migration" is not recognized
I had this problem in Visual Studio 2013. I reinstalled NuGet Package Manager:
https://marketplace.visualstudio.com/items?itemName=NuGetTeam.NuGetPackageManagerforVisualStudio2013
How to select element using XPATH syntax on Selenium for Python?
HTML
<div id='a'>
<div>
<a class='click'>abc</a>
</div>
</div>
You could use the XPATH as :
//div[@id='a']//a[@class='click']
output
<a class="click">abc</a>
That said your Python code should be as :
driver.find_element_by_xpath("//div[@id='a']//a[@class='click']")
How do you reinstall an app's dependencies using npm?
Follow this step to re install node modules and update them
works even if node_modules folder does not exist. now execute the following command synchronously. you can also use "npm update" but I think this'd preferred way
npm outdated // not necessary to run this command, but this will show outdated dependencies
npm install -g npm-check-updates // to install the "ncu" package
ncu -u --packageFile=package.json // to update dependencies version in package.json...don't run this command if you don't need to update the version
npm install: will install dependencies in your package.json file.
if you're okay with the version of your dependencies in your package.json file, no need to follow those steps just run
npm install
Set proxy through windows command line including login parameters
IE can set username and password proxies, so maybe setting it there and import does work
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyEnable /t REG_DWORD /d 1
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyServer /t REG_SZ /d name:port
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyUser /t REG_SZ /d username
reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings" /v ProxyPass /t REG_SZ /d password
netsh winhttp import proxy source=ie
How to get name of calling function/method in PHP?
As of php 5.4 you can use
$dbt=debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS,2);
$caller = isset($dbt[1]['function']) ? $dbt[1]['function'] : null;
This will not waste memory as it ignores arguments and returns only the last 2 backtrace stack entries, and will not generate notices as other answers here.
"unable to locate adb" using Android Studio
open Studio settings-->System settings --> Android SDK --> select SDK tool tab -->> select "Android SDK platform tool" and install
How to enable C++11 in Qt Creator?
As an alternative for handling both cases addressed in Ali's excellent answer, I usually add
# With C++11 support
greaterThan(QT_MAJOR_VERSION, 4){
CONFIG += c++11
} else {
QMAKE_CXXFLAGS += -std=c++0x
}
to my project files. This can be handy when you don't really care much about which Qt version is people using in your team, but you want them to have C++11 enabled in any case.
How to tell CRAN to install package dependencies automatically?
On your own system, try
install.packages("foo", dependencies=...)
with the dependencies= argument is documented as
dependencies: logical indicating to also install uninstalled packages
which these packages depend on/link to/import/suggest (and so
on recursively). Not used if ‘repos = NULL’. Can also be a
character vector, a subset of ‘c("Depends", "Imports",
"LinkingTo", "Suggests", "Enhances")’.
Only supported if ‘lib’ is of length one (or missing), so it
is unambiguous where to install the dependent packages. If
this is not the case it is ignored, with a warning.
The default, ‘NA’, means ‘c("Depends", "Imports",
"LinkingTo")’.
‘TRUE’ means (as from R 2.15.0) to use ‘c("Depends",
"Imports", "LinkingTo", "Suggests")’ for ‘pkgs’ and
‘c("Depends", "Imports", "LinkingTo")’ for added
dependencies: this installs all the packages needed to run
‘pkgs’, their examples, tests and vignettes (if the package
author specified them correctly).
so you probably want a value TRUE.
In your package, list what is needed in Depends:, see the
Writing R Extensions manual which is pretty clear on this.
How to access parent Iframe from JavaScript
Once id of iframe is set, you can access iframe from inner document as shown below.
var iframe = parent.document.getElementById(frameElement.id);
Works well in IE, Chrome and FF.
Console.log(); How to & Debugging javascript
Breakpoints and especially conditional breakpoints are your friends.
Also you can write small assert like function which will check values and throw exceptions if needed in debug version of site (some variable is set to true or url has some parameter)
jQuery if statement, syntax
To add to what the others are saying, A and B can be function calls as well that return boolean values. If A returns false then B would never be called.
if (A() && B()) {
// if A() returns false then B() is never called...
}
What are ABAP and SAP?
with SAP, you might be referring to a popular business software:
http://en.wikipedia.org/wiki/SAP_AG
And according to Wikipedia, ABAP is a programming language (short for Advanced Business Application Programming) created by SAP AG.
Input type number "only numeric value" validation
I had a similar problem, too: I wanted numbers and null on an input field that is not required. Worked through a number of different variations. I finally settled on this one, which seems to do the trick. You place a Directive, ntvFormValidity, on any form control that has native invalidity and that doesn't swizzle that invalid state into ng-invalid.
Sample use:
<input type="number" formControlName="num" placeholder="0" ntvFormValidity>
Directive definition:
import { Directive, Host, Self, ElementRef, AfterViewInit } from '@angular/core';
import { FormControlName, FormControl, Validators } from '@angular/forms';
@Directive({
selector: '[ntvFormValidity]'
})
export class NtvFormControlValidityDirective implements AfterViewInit {
constructor(@Host() private cn: FormControlName, @Host() private el: ElementRef) { }
/*
- Angular doesn't fire "change" events for invalid <input type="number">
- We have to check the DOM object for browser native invalid state
- Add custom validator that checks native invalidity
*/
ngAfterViewInit() {
var control: FormControl = this.cn.control;
// Bridge native invalid to ng-invalid via Validators
const ntvValidator = () => !this.el.nativeElement.validity.valid ? { error: "invalid" } : null;
const v_fn = control.validator;
control.setValidators(v_fn ? Validators.compose([v_fn, ntvValidator]) : ntvValidator);
setTimeout(()=>control.updateValueAndValidity(), 0);
}
}
The challenge was to get the ElementRef from the FormControl so that I could examine it. I know there's @ViewChild, but I didn't want to have to annotate each numeric input field with an ID and pass it to something else. So, I built a Directive which can ask for the ElementRef.
On Safari, for the HTML example above, Angular marks the form control invalid on inputs like "abc".
I think if I were to do this over, I'd probably build my own CVA for numeric input fields as that would provide even more control and make for a simple html.
Something like this:
<my-input-number formControlName="num" placeholder="0">
PS: If there's a better way to grab the FormControl for the directive, I'm guessing with Dependency Injection and providers on the declaration, please let me know so I can update my Directive (and this answer).
Is there a way to remove unused imports and declarations from Angular 2+?
If you're a heavy visual studio user, you can simply open your preference settings and add the following to your settings.json:
...
"editor.formatOnSave": true,
"editor.codeActionsOnSave": {
"source.organizeImports": true
}
....
Hopefully this can be helpful!
OSX - How to auto Close Terminal window after the "exit" command executed.
in Terminal.app
Preferences > Profiles > (Select a Profile) > Shell.
on 'When the shell exits' chosen 'Close the window'
Cancel a vanilla ECMAScript 6 Promise chain
Promise can be cancelled with the help of AbortController.
Is there a method for clearing then: yes you can reject the promise with
AbortControllerobject and then thepromisewill bypass all then blocks and go directly to the catch block.
Example:
import "abortcontroller-polyfill";
let controller = new window.AbortController();
let signal = controller.signal;
let elem = document.querySelector("#status")
let example = (signal) => {
return new Promise((resolve, reject) => {
let timeout = setTimeout(() => {
elem.textContent = "Promise resolved";
resolve("resolved")
}, 2000);
signal.addEventListener('abort', () => {
elem.textContent = "Promise rejected";
clearInterval(timeout);
reject("Promise aborted")
});
});
}
function cancelPromise() {
controller.abort()
console.log(controller);
}
example(signal)
.then(data => {
console.log(data);
})
.catch(error => {
console.log("Catch: ", error)
});
document.getElementById('abort-btn').addEventListener('click', cancelPromise);
Html
<button type="button" id="abort-btn" onclick="abort()">Abort</button>
<div id="status"> </div>
Note: need to add polyfill, not supported in all browser.
Live Example
If input value is blank, assign a value of "empty" with Javascript
This can be done using HTML5's placeHolder or using JavaScript. Checkout this post.
DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") is returning AM time instead of PM time?
Use HH for 24 hour hours format:
DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")
Or the tt format specifier for the AM/PM part:
DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss tt")
Take a look at the custom Date and Time format strings documentation.
ADB Android Device Unauthorized
It's likely that the device is no longer authorized on ADB for whatever reason.
1. Check if authorized:
<ANDROID_SDK_HOME>\platform-tools>adb devices
List of devices attached
4df798d76f98cf6d unauthorized
2. Revoke USB Debugging on phone
If the device is shown as unauthorized, go to the developer options on the phone and click "Revoke USB debugging authorization" (tested with JellyBean & Samsung GalaxyIII).
3. Restart ADB Server:
Then restarted adb server
adb kill-server
adb start-server
4. Reconnect the device
The device will ask if you are agree to connect the computer id. You need to confirm it.
5. Now Check the device
It is now authorized!
adb devices
<ANDROID_SDK_HOME>\platform-tools>adb devices
List of devices attached
4df798d76f98cf6d device
How to push files to an emulator instance using Android Studio
adb push [file path on your computer] [file path on your mobile]
Using sudo with Python script
It works in python 2.7 and 3.8:
from subprocess import Popen, PIPE
from shlex import split
proc = Popen(split('sudo -S %s' % command), bufsize=0, stdout=PIPE, stdin=PIPE, stderr=PIPE)
proc.stdin.write((password +'\n').encode()) # write as bytes
proc.stdin.flush() # need if not bufsize=0 (unbuffered stdin)
without .flush() password will not reach sudo if stdin buffered.
In python 2.7 Popen by default used bufsize=0 and stdin.flush() was not needed.
For secure using, create password file in protected directory:
mkdir --mode=700 ~/.prot_dir
nano ~/.prot_dir/passwd.txt
chmod 600 ~/.prot_dir/passwd.txt
at start your py-script read password from ~/.prot_dir/passwd.txt
with open(os.environ['HOME'] +'/.prot_dir/passwd.txt') as f:
password = f.readline().rstrip()
Shortest way to check for null and assign another value if not
You are looking for the C# coalesce operator: ??. This operator takes a left and right argument. If the left hand side of the operator is null or a nullable with no value it will return the right argument. Otherwise it will return the left.
var x = somePossiblyNullValue ?? valueIfNull;
Easy way to test a URL for 404 in PHP?
this is just and slice of code, hope works for you
$ch = @curl_init();
@curl_setopt($ch, CURLOPT_URL, 'http://example.com');
@curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1");
@curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
@curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
@curl_setopt($ch, CURLOPT_TIMEOUT, 10);
$response = @curl_exec($ch);
$errno = @curl_errno($ch);
$error = @curl_error($ch);
$response = $response;
$info = @curl_getinfo($ch);
return $info['http_code'];
Android ListView with Checkbox and all clickable
Below code will help you:
public class DeckListAdapter extends BaseAdapter{
private LayoutInflater mInflater;
ArrayList<String> teams=new ArrayList<String>();
ArrayList<Integer> teamcolor=new ArrayList<Integer>();
public DeckListAdapter(Context context) {
// Cache the LayoutInflate to avoid asking for a new one each time.
mInflater = LayoutInflater.from(context);
teams.add("Upload");
teams.add("Download");
teams.add("Device Browser");
teams.add("FTP Browser");
teams.add("Options");
teamcolor.add(Color.WHITE);
teamcolor.add(Color.LTGRAY);
teamcolor.add(Color.WHITE);
teamcolor.add(Color.LTGRAY);
teamcolor.add(Color.WHITE);
}
public int getCount() {
return teams.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.decklist, null);
holder = new ViewHolder();
holder.icon = (ImageView) convertView.findViewById(R.id.deckarrow);
holder.text = (TextView) convertView.findViewById(R.id.textname);
.......here you can use holder.text.setonclicklistner(new View.onclick.
for each textview
System.out.println(holder.text.getText().toString());
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.text.setText(teams.get(position));
if(position<teamcolor.size())
holder.text.setBackgroundColor(teamcolor.get(position));
holder.icon.setImageResource(R.drawable.arraocha);
return convertView;
}
class ViewHolder {
ImageView icon;
TextView text;
}
}
Hope this helps.
What is the difference between tree depth and height?
Another way to understand those concept is as follow: Depth: Draw a horizontal line at the root position and treat this line as ground. So the depth of the root is 0, and all its children are grow downward so each level of nodes has the current depth + 1.
Height: Same horizontal line but this time the ground position is external nodes, which is the leaf of tree and count upward.
Aligning a button to the center
For me it worked using flexbox, which is in my opinion the cleanest solution.
Add a css class around the parent div / element with :
.parent {
display: flex;
}
and for the button use:
.button {
justify-content: center;
}
You should use a parent div, otherwise the button doesn't 'know' what the middle of the page / element is.
If this is not working, try :
#wrapper {
display:flex;
justify-content: center;
}
Displaying a vector of strings in C++
Your vector<string> userString has size 0, so the loop is never entered. You could start with a vector of a given size:
vector<string> userString(10);
string word;
string sentence;
for (decltype(userString.size()) i = 0; i < userString.size(); ++i)
{
cin >> word;
userString[i] = word;
sentence += userString[i] + " ";
}
although it is not clear why you need the vector at all:
string word;
string sentence;
for (int i = 0; i < 10; ++i)
{
cin >> word;
sentence += word + " ";
}
If you don't want to have a fixed limit on the number of input words, you can use std::getline in a while loop, checking against a certain input, e.g. "q":
while (std::getline(std::cin, word) && word != "q")
{
sentence += word + " ";
}
This will add words to sentence until you type "q".
Check if list contains element that contains a string and get that element
for (int i = 0; i < myList.Length; i++)
{
if (myList[i].Contains(myString)) // (you use the word "contains". either equals or indexof might be appropriate)
{
return i;
}
}
Old fashion loops are almost always the fastest.
Click event on select option element in chrome
The easy way to change the select, and update it is this.
// BY id
$('#select_element_selector').val('value').change();
another example:
//By tag
$('[name=selectxD]').val('value').change();
another example:
$("#select_element_selector").val('value').trigger('chosen:updated');
List of all special characters that need to be escaped in a regex
You can look at the javadoc of the Pattern class: http://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html
You need to escape any char listed there if you want the regular char and not the special meaning.
As a maybe simpler solution, you can put the template between \Q and \E - everything between them is considered as escaped.
How to hide a button programmatically?
Hidde:
BUTTON.setVisibility(View.GONE);
Show:
BUTTON.setVisibility(View.VISIBLE);
Can't Autowire @Repository annotated interface in Spring Boot
In SpringBoot, the JpaRepository are not auto-enabled by default. You have to explicitly add
@EnableJpaRepositories("packages")
@EntityScan("packages")
How can I get all a form's values that would be submitted without submitting
Depending on the type of input types you're using on your form, you should be able to grab them using standard jQuery expressions.
Example:
// change forms[0] to the form you're trying to collect elements from... or remove it, if you need all of them
var input_elements = $("input, textarea", document.forms[0]);
Check out the documentation for jQuery expressions on their site for more info: http://docs.jquery.com/Core/jQuery#expressioncontext
Maven: best way of linking custom external JAR to my project?
Change your systemPath.
<dependency>
<groupId>stuff</groupId>
<artifactId>library</artifactId>
<version>1.0</version>
<systemPath>${project.basedir}/MyLibrary.jar</systemPath>
<scope>system</scope>
</dependency>
Java error: Implicit super constructor is undefined for default constructor
Short answer: Add a constructor with no argument in base/parent/super class. i.e for example,
class Parent{
String name;
int age;
String occupation;
//empty constructor
public Parent(){
}
public Parent(String name, int age, String employment){
this.name = name;
this.age = age;
this.occupation = employment;
}
}
// You can have any additional constructors as you wish aka constructor overloading here in parent class.
If a super class does not have the no-argument constructor then you will get the compile-time error. Object does have such the constructor, so if Object is a only super class then there is no problem.
// then let's inherit
class Child extends Parent{
Child(String name, int age){
this.name = name;
this.age = age;
}
}
With super(), a super class no-argument constructor is called and with super(parameter list), a super class constructor with the matching parameter list is called.
How do I keep the screen on in my App?
Lots of answers already exist here! I am answering this question with additional and reliable solutions:
Using PowerManager.WakeLock is not so reliable a solution, as the app requires additional permissions.
<uses-permission android:name="android.permission.WAKE_LOCK" />
Also, if it accidentally remains holding the wake lock, it can leave the screen on.
So, I recommend not using the PowerManager.WakeLock solution. Instead of this, use any of the following solutions:
First:
We can use getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); in onCreate()
@Override
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
Second:
we can use keepScreenOn
1. implementation using setKeepScreenOn() in java code:
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
View v = getLayoutInflater().inflate(R.layout.driver_home, null);// or any View (incase generated programmatically )
v.setKeepScreenOn(true);
setContentView(v);
}
Docs http://developer.android.com/reference/android/view/View.html#setKeepScreenOn(boolean)
2. Adding keepScreenOn to xml layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:keepScreenOn="true" >
Docs http://developer.android.com/reference/android/view/View.html#attr_android%3akeepScreenOn
Notes (some useful points):
- It doesn't matter that
keepScreenOnshould be used on a Main/Root/Parent View. It can be used with any child view and will work the same way it works in a parent view. - The only thing that matters is that the view's visibility must be visible. Otherwise, it will not work!
jQuery - Detect value change on hidden input field
It is possible to use Object.defineProperty() in order to redefine the 'value' property of the input element and do anything during its changing.
Object.defineProperty() allows us to define a getter and setter for a property, thus controlling it.
replaceWithWrapper($("#hid1")[0], "value", function(obj, property, value) {
console.log("new value:", value)
});
function replaceWithWrapper(obj, property, callback) {
Object.defineProperty(obj, property, new function() {
var _value = obj[property];
return {
set: function(value) {
_value = value;
callback(obj, property, value)
},
get: function() {
return _value;
}
}
});
}
$("#hid1").val(4);
Why does fatal error "LNK1104: cannot open file 'C:\Program.obj'" occur when I compile a C++ project in Visual Studio?
Solution 1 (for my case): restart windows Explorer process (yes, the windows file manager).
Solution 2:
- Close Visual Studio. Windows Logoff
- Logon, reopen Visual Studio
- Build as usual. It now builds and can access the problematic file.
I presume sometimes the file system or whoever is controlling it gets lost with its permissions. Before restarting the windows session, tried to kill zombie msbuild32.exe processes, restart visual studio, check none even showing the problem file on. No build configuration issues. It happens now and then. Some internal thing in Windows does not fix up, needs a restart.
Writing image to local server
I suggest you use http-request, so that even redirects are managed.
var http = require('http-request');
var options = {url: 'http://localhost/foo.pdf'};
http.get(options, '/path/to/foo.pdf', function (error, result) {
if (error) {
console.error(error);
} else {
console.log('File downloaded at: ' + result.file);
}
});
Replace all whitespace characters
We can also use this if we want to change all multiple joined blank spaces with a single character:
str.replace(/\s+/g,'X');
See it in action here: https://regex101.com/r/d9d53G/1
Explanation
/
\s+/ g
\s+matches any whitespace character (equal to[\r\n\t\f\v ])+Quantifier — Matches between one and unlimited times, as many times as possible, giving back as needed (greedy)
- Global pattern flags
- g modifier: global. All matches (don't return after first match)
java.util.MissingResourceException: Can't find bundle for base name 'property_file name', locale en_US
Use the Resource like
ResourceBundle rb = ResourceBundle.getBundle("com//sudeep//internationalization//MyApp",locale);
or
ResourceBundle rb = ResourceBundle.getBundle("com.sudeep.internationalization.MyApp",locale);
Just give the qualified path .. Its working for me!!!
C# List<> Sort by x then y
The trick is to implement a stable sort. I've created a Widget class that can contain your test data:
public class Widget : IComparable
{
int x;
int y;
public int X
{
get { return x; }
set { x = value; }
}
public int Y
{
get { return y; }
set { y = value; }
}
public Widget(int argx, int argy)
{
x = argx;
y = argy;
}
public int CompareTo(object obj)
{
int result = 1;
if (obj != null && obj is Widget)
{
Widget w = obj as Widget;
result = this.X.CompareTo(w.X);
}
return result;
}
static public int Compare(Widget x, Widget y)
{
int result = 1;
if (x != null && y != null)
{
result = x.CompareTo(y);
}
return result;
}
}
I implemented IComparable, so it can be unstably sorted by List.Sort().
However, I also implemented the static method Compare, which can be passed as a delegate to a search method.
I borrowed this insertion sort method from C# 411:
public static void InsertionSort<T>(IList<T> list, Comparison<T> comparison)
{
int count = list.Count;
for (int j = 1; j < count; j++)
{
T key = list[j];
int i = j - 1;
for (; i >= 0 && comparison(list[i], key) > 0; i--)
{
list[i + 1] = list[i];
}
list[i + 1] = key;
}
}
You would put this in the sort helpers class that you mentioned in your question.
Now, to use it:
static void Main(string[] args)
{
List<Widget> widgets = new List<Widget>();
widgets.Add(new Widget(0, 1));
widgets.Add(new Widget(1, 1));
widgets.Add(new Widget(0, 2));
widgets.Add(new Widget(1, 2));
InsertionSort<Widget>(widgets, Widget.Compare);
foreach (Widget w in widgets)
{
Console.WriteLine(w.X + ":" + w.Y);
}
}
And it outputs:
0:1
0:2
1:1
1:2
Press any key to continue . . .
This could probably be cleaned up with some anonymous delegates, but I'll leave that up to you.
EDIT: And NoBugz demonstrates the power of anonymous methods...so, consider mine more oldschool :P
How do you fade in/out a background color using jquery?
This exact functionality (3 second glow to highlight a message) is implemented in the jQuery UI as the highlight effect
https://api.jqueryui.com/highlight-effect/
Color and duration are variable
How can I add a key/value pair to a JavaScript object?
There are two ways to add new properties to an object:
var obj = {
key1: value1,
key2: value2
};
Using dot notation:
obj.key3 = "value3";
Using square bracket notation:
obj["key3"] = "value3";
The first form is used when you know the name of the property. The second form is used when the name of the property is dynamically determined. Like in this example:
var getProperty = function (propertyName) {
return obj[propertyName];
};
getProperty("key1");
getProperty("key2");
getProperty("key3");
A real JavaScript array can be constructed using either:
The Array literal notation:
var arr = [];
The Array constructor notation:
var arr = new Array();
How can I count the number of children?
You can do this using jQuery:
This method gets a list of its children then counts the length of that list, as simple as that.
$("ul").find("*").length;
The find() method traverses DOM downwards along descendants, all the way down to the last descendant.
Note: children() method traverses a single level down the DOM tree.
Angular EXCEPTION: No provider for Http
With the Sept 14, 2016 Angular 2.0.0 release, you are using still using HttpModule. Your main app.module.ts would look something like this:
import { HttpModule } from '@angular/http';
@NgModule({
bootstrap: [ AppComponent ],
declarations: [ AppComponent ],
imports: [
BrowserModule,
HttpModule,
// ...more modules...
],
providers: [
// ...providers...
]
})
export class AppModule {}
Then in your app.ts you can bootstrap as such:
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppModule } from './app/main/app.module';
platformBrowserDynamic().bootstrapModule(AppModule);
How to execute a JavaScript function when I have its name as a string
If you want to call a function of an object instead of a global function with window["functionName"]. You can do it like;
var myObject=new Object();
myObject["functionName"](arguments);
Example:
var now=new Date();
now["getFullYear"]()
SOAP or REST for Web Services?
My general rule is that if you want a browser web client to directly connect to a service then you should probably use REST. If you want to pass structured data between back-end services then use SOAP.
SOAP can be a real pain to set up sometimes and is often overkill for simple web client and server data exchanges. Unfortunately, most simple programming examples I've seen (and learned from) somewhat reenforce this perception.
That said, SOAP really shines when you start combining multiple SOAP services together as part of a larger process driven by a data workflow (think enterprise software). This is something that many of the SOAP programming examples fail to convey because a simple SOAP operation to do something, like fetch the price of a stock, is generally overcomplicated for what it does by itself unless it is presented in the context of providing a machine readable API detailing specific functions with set data formats for inputs and outputs that is, in turn, scripted by a larger process.
This is sad, in a way, as it really gives SOAP a bad reputation because it is difficult to show the advantages of SOAP without presenting it in the full context of how the final product is used.
Concatenate chars to form String in java
If the size of the string is fixed, you might find easier to use an array of chars. If you have to do this a lot, it will be a tiny bit faster too.
char[] chars = new char[3];
chars[0] = 'i';
chars[1] = 'c';
chars[2] = 'e';
return new String(chars);
Also, I noticed in your original question, you use the Char class. If your chars are not nullable, it is better to use the lowercase char type.
Which Android IDE is better - Android Studio or Eclipse?
Both are equally good. With Android Studio you have ADT tools integrated, and with eclipse you need to integrate them manually. With Android Studio, it feels like a tool designed from the outset with Android development in mind. Go ahead, they have same features.
Error while inserting date - Incorrect date value:
This is the date format:
The DATE type is used for values with a date part but no time part. MySQL retrieves and displays DATE values in 'YYYY-MM-DD' format. The supported range is '1000-01-01' to '9999-12-31'.
Why do you insert '07-25-2012' format when MySQL format is '2012-07-25'?. Actually you get this error if the sql_mode is traditional/strict mode else it just enters 0000-00-00 and gives a warning: 1265 - Data truncated for column 'col1' at row 1.
How do I remove a submodule?
If the submodule was accidentally added because you added, committed and pushed a folder that was already a Git repository (contained .git), you won’t have a .gitmodules file to edit, or anything in .git/config. In this case all you need is :
git rm --cached subfolder
git add subfolder
git commit -m "Enter message here"
git push
FWIW, I also removed the .git folder before doing the git add.
Remove leading and trailing spaces?
Starting file:
line 1
line 2
line 3
line 4
Code:
with open("filename.txt", "r") as f:
lines = f.readlines()
for line in lines:
stripped = line.strip()
print(stripped)
Output:
line 1
line 2
line 3
line 4
Getting the source HTML of the current page from chrome extension
Here is my solution:
chrome.runtime.onMessage.addListener(function(request, sender) {
if (request.action == "getSource") {
this.pageSource = request.source;
var title = this.pageSource.match(/<title[^>]*>([^<]+)<\/title>/)[1];
alert(title)
}
});
chrome.tabs.query({ active: true, currentWindow: true }, tabs => {
chrome.tabs.executeScript(
tabs[0].id,
{ code: 'var s = document.documentElement.outerHTML; chrome.runtime.sendMessage({action: "getSource", source: s});' }
);
});
Android Studio: Default project directory
In android studio 2.3.3 (windows) you must go to C:\User\ (Name)\ .AndroidStudio2.3\config\option open recentProjects.xml And change your directory
<option name="lastProjectLocation" value="YOUR DIRECTORY" />
How to append one DataTable to another DataTable
You could let your DataAdapter do the work. DataAdapter.Fill(DataTable) will append your new rows to any existing rows in DataTable.
Joining Spark dataframes on the key
One way
// join type can be inner, left, right, fullouter
val mergedDf = df1.join(df2, Seq("keyCol"), "inner")
// keyCol can be multiple column names seperated by comma
val mergedDf = df1.join(df2, Seq("keyCol1", "keyCol2"), "left")
Another way
import spark.implicits._
val mergedDf = df1.as("d1").join(df2.as("d2"), ($"d1.colName" === $"d2.colName"))
// to select specific columns as output
val mergedDf = df1.as("d1").join(df2.as("d2"), ($"d1.colName" === $"d2.colName")).select($"d1.*", $"d2.anotherColName")
What is the difference between mocking and spying when using Mockito?
If there is an object with 8 methods and you have a test where you want to call 7 real methods and stub one method you have two options:
- Using a mock you would have to set it up by invoking 7 callRealMethod and stub one method
- Using a
spyyou have to set it up by stubbing one method
The official documentation on doCallRealMethod recommends using a spy for partial mocks.
See also javadoc spy(Object) to find out more about partial mocks. Mockito.spy() is a recommended way of creating partial mocks. The reason is it guarantees real methods are called against correctly constructed object because you're responsible for constructing the object passed to spy() method.
How to reduce a huge excel file
I save files in .XLSB format to cut size. The XLSB also allows for VBA and macros to stay with the file. I've seen 50 meg files down to less than 10 with the Binary formatting.
"Javac" doesn't work correctly on Windows 10
just add C:\Program Files\Java\jdk1.7.0_80\bin as the path in environmental variables. no need to add java.exe and javac.exe to that path. IT WORKS
Angular 2 two way binding using ngModel is not working
Angular has released its final version on 15th of September. Unlike Angular 1 you can use ngModel directive in Angular 2 for two way data binding, but you need write it in a bit different way like [(ngModel)] (Banana in a box syntax). Almost all angular2 core directives doesn't support kebab-case now instead you should use camelCase.
Now
ngModeldirective belongs toFormsModule, that's why you shouldimporttheFormsModulefrom@angular/formsmodule insideimportsmetadata option ofAppModule(NgModule). Thereafter you can usengModeldirective inside on your page.
app/app.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'my-app',
template: `<h1>My First Angular 2 App</h1>
<input type="text" [(ngModel)]="myModel"/>
{{myModel}}
`
})
export class AppComponent {
myModel: any;
}
app/app.module.ts
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
@NgModule({
imports: [ BrowserModule, FormsModule ], //< added FormsModule here
declarations: [ AppComponent ],
bootstrap: [ AppComponent ]
})
export class AppModule { }
app/main.ts
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppModule } from './app.module';
const platform = platformBrowserDynamic();
platform.bootstrapModule(AppModule);
get all keys set in memcached
Bash
To get list of keys in Bash, follow the these steps.
First, define the following wrapper function to make it simple to use (copy and paste into shell):
function memcmd() {
exec {memcache}<>/dev/tcp/localhost/11211
printf "%s\n%s\n" "$*" quit >&${memcache}
cat <&${memcache}
}
Memcached 1.4.31 and above
You can use lru_crawler metadump all command to dump (most of) the metadata for (all of) the items in the cache.
As opposed to
cachedump, it does not cause severe performance problems and has no limits on the amount of keys that can be dumped.
Example command by using the previously defined function:
memcmd lru_crawler metadump all
See: ReleaseNotes1431.
Memcached 1.4.30 and below
Get list of slabs by using items statistics command, e.g.:
memcmd stats items
For each slub class, you can get list of items by specifying slub id along with limit number (0 - unlimited):
memcmd stats cachedump 1 0
memcmd stats cachedump 2 0
memcmd stats cachedump 3 0
memcmd stats cachedump 4 0
...
Note: You need to do this for each memcached server.
To list all the keys from all stubs, here is the one-liner (per one server):
for id in $(memcmd stats items | grep -o ":[0-9]\+:" | tr -d : | sort -nu); do
memcmd stats cachedump $id 0
done
Note: The above command could cause severe performance problems while accessing the items, so it's not advised to run on live.
Notes:
stats cachedumponly dumps theHOT_LRU(IIRC?), which is managed by a background thread as activity happens. This means under a new enough version which the 2Q algo enabled, you'll get snapshot views of what's in just one of the LRU's.If you want to view everything,
lru_crawler metadump 1(orlru_crawler metadump all) is the new mostly-officially-supported method that will asynchronously dump as many keys as you want. you'll get them out of order but it hits all LRU's, and unless you're deleting/replacing items multiple runs should yield the same results.
Source: GH-405.
Related:
- List all objects in memcached
- Writing a Redis client in pure bash (it's Redis, but very similar approach)
- Check other available commands at https://memcached.org/wiki
- Check out the
protocol.txtdocs file.
How to use comparison and ' if not' in python?
There are two ways. In case of doubt, you can always just try it. If it does not work, you can add extra braces to make sure, like that:
if not ((u0 <= u) and (u < u0+step)):
mySQL Error 1040: Too Many Connection
The issue noted clearly in https://dev.mysql.com/doc/refman/8.0/en/too-many-connections.html:
If clients encounter Too many connections errors when attempting to connect to the MySQL server, all available connections are in use by other clients.
I got resolved the issue after a few minutes, it seems that connection was been released by other clients, also I tried with restarting vs and workbench at same time.
how to start stop tomcat server using CMD?
you can use this trick to run tomcat using cmd and directly by tomcat bin folder.
1. set the path of jdk.
2.
To set path. go to Desktop and right click on computer icon. Click the Properties
go to Advance System Settings.
then Click Advance to Environment variables.
Click new and set path AS,
in the column Variable name=JAVA_HOME
Variable Value=C:\Program Files\Java\jdk1.6.0_19
Click ok ok.
now path is stetted.
3.
Go to tomcat folder where you installed the tomcat. go to bin folder. there are two window batch files.
1.Startup
2.Shutdown.
By using cmd if you installed the tomcate in D Drive
type on cmd screen
D:
Cd tomcat\bin then type Startup.
4. By clicking them you can start and stop the tomcat.
5.
Final step.
if you start and want to check it.
open a Browser in URL bar type.
**HTTP://localhost:8080/**
Entityframework Join using join method and lambdas
You can find a few examples here:
// Fill the DataSet. DataSet ds = new DataSet(); ds.Locale = CultureInfo.InvariantCulture; FillDataSet(ds); DataTable contacts = ds.Tables["Contact"]; DataTable orders = ds.Tables["SalesOrderHeader"]; var query = contacts.AsEnumerable().Join(orders.AsEnumerable(), order => order.Field<Int32>("ContactID"), contact => contact.Field<Int32>("ContactID"), (contact, order) => new { ContactID = contact.Field<Int32>("ContactID"), SalesOrderID = order.Field<Int32>("SalesOrderID"), FirstName = contact.Field<string>("FirstName"), Lastname = contact.Field<string>("Lastname"), TotalDue = order.Field<decimal>("TotalDue") }); foreach (var contact_order in query) { Console.WriteLine("ContactID: {0} " + "SalesOrderID: {1} " + "FirstName: {2} " + "Lastname: {3} " + "TotalDue: {4}", contact_order.ContactID, contact_order.SalesOrderID, contact_order.FirstName, contact_order.Lastname, contact_order.TotalDue); }
Or just google for 'linq join method syntax'.
Explicit Return Type of Lambda
You can have more than one statement when still return:
[]() -> your_type {return (
your_statement,
even_more_statement = just_add_comma,
return_value);}
How to migrate GIT repository from one server to a new one
If you want to migrate all branches and tags you should use the following commands:
git clone --mirror [oldUrl]
to clone the old repo with all branches
cd the_repo
git remote add remoteName newRepoUrl
to setup a new remote
git push -f --tags remoteName refs/heads/*:refs/heads/*
to push all refs under refs/heads (which is probably what you want)
How to get span tag inside a div in jQuery and assign a text?
Vanilla JS, without jQuery:
document.querySelector('#message span').innerHTML = 'hello world!'
Available in all browsers: https://caniuse.com/#search=querySelector
the easiest way to convert matrix to one row vector
Try this: B = A ( : ), or try the reshape function.
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/reshape.html
Android Studio was unable to find a valid Jvm (Related to MAC OS)
For those who were having trouble creating a script that launched on startup, as an alternative you can add this .plist to your LaunchAgents folder. This may be a more appropriate way of adding environment variables to the system since Yosemite decided to do away with launchd.conf. This should also work across user accounts due to the nature of the LaunchAgents folder, but I haven't tested that.
To do this, create a .plist file with the following name and path:
/Library/LaunchAgents/setenv.STUDIO_JDK.plist
and the contents:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>setenv.STUDIO_JDK</string>
<key>ProgramArguments</key>
<array>
<string>sh</string>
<string>-c</string>
<string>
launchctl setenv STUDIO_JDK /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk
</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>ServiceIPC</key>
<false/>
<key>LaunchOnlyOnce</key>
<true/>
<key>KeepAlive</key>
<false/>
</dict>
</plist>
Then change file properties by running the following commands in Terminal:
sudo chmod 644 /Library/LaunchAgents/setenv.STUDIO_JDK.plist
sudo chown root /Library/LaunchAgents/setenv.STUDIO_JDK.plist
sudo chgrp wheel /Library/LaunchAgents/setenv.STUDIO_JDK.plist
Notes:
1) You may need to change 'jdk1.8.0_25.jdk' to match the version that you have on your computer.
2) I tried to use "jdk1.8.*.jdk" to try and account for varying Java * versions, but when I opened Android Studio I got the no JVM error even though if you run "echo $STUDIO_JDK" it returns the correct path. Perhaps someone has some insight as to how to fix that issue.
Double % formatting question for printf in Java
Yes, %d means decimal, but it means decimal number system, not decimal point.
Further, as a complement to the former post, you can also control the number of decimal points to show. Try this,
System.out.printf("%.2f %.1f",d,f); // prints 1.20 1.2
For more please refer to the API docs.
Text File Parsing in Java
Have a look at these pages. They contain many open source CSV parsers. JSaPar is one of them.
Global variables in Javascript across multiple files
I think you should be using "local storage" rather than global variables.
If you are concerned that "local storage" may not be supported in very old browsers, consider using an existing plug-in which checks the availability of "local storage" and uses other methods if it isn't available.
I used http://www.jstorage.info/ and I'm happy with it so far.
Can't change table design in SQL Server 2008
Just go to the SQL Server Management Studio -> Tools -> Options -> Designer; and Uncheck the option "prevent saving changes that require table re-creation".
Setting HTTP headers
All of the above answers are wrong because they fail to handle the OPTIONS preflight request, the solution is to override the mux router's interface. See AngularJS $http get request failed with custom header (alllowed in CORS)
func main() {
r := mux.NewRouter()
r.HandleFunc("/save", saveHandler)
http.Handle("/", &MyServer{r})
http.ListenAndServe(":8080", nil);
}
type MyServer struct {
r *mux.Router
}
func (s *MyServer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
if origin := req.Header.Get("Origin"); origin != "" {
rw.Header().Set("Access-Control-Allow-Origin", origin)
rw.Header().Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
rw.Header().Set("Access-Control-Allow-Headers",
"Accept, Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization")
}
// Stop here if its Preflighted OPTIONS request
if req.Method == "OPTIONS" {
return
}
// Lets Gorilla work
s.r.ServeHTTP(rw, req)
}
Formatting PowerShell Get-Date inside string
You can use the -f operator
$a = "{0:D}" -f (get-date)
$a = "{0:dddd}" -f (get-date)
Spécificator Type Example (with [datetime]::now)
d Short date 26/09/2002
D Long date jeudi 26 septembre 2002
t Short Hour 16:49
T Long Hour 16:49:31
f Date and hour jeudi 26 septembre 2002 16:50
F Long Date and hour jeudi 26 septembre 2002 16:50:51
g Default Date 26/09/2002 16:52
G Long default Date and hour 26/09/2009 16:52:12
M Month Symbol 26 septembre
r Date string RFC1123 Sat, 26 Sep 2009 16:54:50 GMT
s Sortable string date 2009-09-26T16:55:58
u Sortable string date universal local hour 2009-09-26 16:56:49Z
U Sortable string date universal GMT hour samedi 26 septembre 2009 14:57:22 (oups)
Y Year symbol septembre 2002
Spécificator Type Example Output Example
dd Jour {0:dd} 10
ddd Name of the day {0:ddd} Jeu.
dddd Complet name of the day {0:dddd} Jeudi
f, ff, … Fractions of seconds {0:fff} 932
gg, … position {0:gg} ap. J.-C.
hh Hour two digits {0:hh} 10
HH Hour two digits (24 hours) {0:HH} 22
mm Minuts 00-59 {0:mm} 38
MM Month 01-12 {0:MM} 12
MMM Month shortcut {0:MMM} Sep.
MMMM complet name of the month {0:MMMM} Septembre
ss Seconds 00-59 {0:ss} 46
tt AM or PM {0:tt} ““
yy Years, 2 digits {0:yy} 02
yyyy Years {0:yyyy} 2002
zz Time zone, 2 digits {0:zz} +02
zzz Complete Time zone {0:zzz} +02:00
: Separator {0:hh:mm:ss} 10:43:20
/ Separator {0:dd/MM/yyyy} 10/12/2002
How to add buttons at top of map fragment API v2 layout
extending de Almeida's answer I am editing code little bit here. since previous code was hiding gps location icon I did following way which worked better.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<RadioGroup
android:id="@+id/radio_group_list_selector"
android:layout_width="match_parent"
android:layout_height="48dp"
android:orientation="horizontal"
android:background="#80000000"
android:padding="4dp" >
<RadioButton
android:id="@+id/radioPopular"
android:layout_width="0dp"
android:layout_height="match_parent"
android:text="@string/Popular"
android:gravity="center_horizontal|center_vertical"
android:layout_weight="1"
android:button="@null"
android:background="@drawable/shape_radiobutton"
android:textColor="@drawable/textcolor_radiobutton" />
<View
android:id="@+id/VerticalLine"
android:layout_width="1dip"
android:layout_height="match_parent"
android:background="#aaa" />
<RadioButton
android:id="@+id/radioAZ"
android:layout_width="0dp"
android:layout_height="match_parent"
android:gravity="center_horizontal|center_vertical"
android:text="@string/AZ"
android:layout_weight="1"
android:button="@null"
android:background="@drawable/shape_radiobutton2"
android:textColor="@drawable/textcolor_radiobutton" />
<View
android:id="@+id/VerticalLine"
android:layout_width="1dip"
android:layout_height="match_parent"
android:background="#aaa" />
<RadioButton
android:id="@+id/radioCategory"
android:layout_width="0dp"
android:layout_height="match_parent"
android:gravity="center_horizontal|center_vertical"
android:text="@string/Category"
android:layout_weight="1"
android:button="@null"
android:background="@drawable/shape_radiobutton2"
android:textColor="@drawable/textcolor_radiobutton" />
<View
android:id="@+id/VerticalLine"
android:layout_width="1dip"
android:layout_height="match_parent"
android:background="#aaa" />
<RadioButton
android:id="@+id/radioNearBy"
android:layout_width="0dp"
android:layout_height="match_parent"
android:gravity="center_horizontal|center_vertical"
android:text="@string/NearBy"
android:layout_weight="1"
android:button="@null"
android:background="@drawable/shape_radiobutton3"
android:textColor="@drawable/textcolor_radiobutton" />
</RadioGroup>
<fragment
xmlns:map="http://schemas.android.com/apk/res-auto"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment"
android:scrollbars="vertical" />
How is a non-breaking space represented in a JavaScript string?
Remember that .text() strips out markup, thus I don't believe you're going to find in a non-markup result.
Made in to an answer....
var p = $('<p>').html(' ');
if (p.text() == String.fromCharCode(160) && p.text() == '\xA0')
alert('Character 160');
Shows an alert, as the ASCII equivalent of the markup is returned instead.
Unable to open a file with fopen()
How are you running the file? Is it from the command line or from an IDE? The directory that your executable is in is not necessarily your working directory.
Try using the full path name in the fopen and see if that fixes it. If so, then the problem is as described.
For example:
file = fopen("c:\\MyDirectory\\TestFile1.txt", "r");
file = fopen("/full/path/to/TestFile1.txt", "r");
Or open up a command window and navigate to the directory where your executable is, then run it manually.
As an aside, you can insert a simple (for Windows or Linux/UNIX/BSD/etc respectively):
system ("cd")
system("pwd")
before the fopen to show which directory you're actually in.
Bootstrap Datepicker - Months and Years Only
For the latest bootstrap-datepicker (1.4.0 at the time of writing), you need to use this:
$('#myDatepicker').datepicker({
format: "mm/yyyy",
startView: "year",
minViewMode: "months"
})
Source: Bootstrap Datepicker Options
Using std::max_element on a vector<double>
min_element and max_element return iterators, not values. So you need *min_element... and *max_element....
How to display the value of the bar on each bar with pyplot.barh()?
I needed the bar labels too, note that my y-axis is having a zoomed view using limits on y axis. The default calculations for putting the labels on top of the bar still works using height (use_global_coordinate=False in the example). But I wanted to show that the labels can be put in the bottom of the graph too in zoomed view using global coordinates in matplotlib 3.0.2. Hope it help someone.
def autolabel(rects,data):
"""
Attach a text label above each bar displaying its height
"""
c = 0
initial = 0.091
offset = 0.205
use_global_coordinate = True
if use_global_coordinate:
for i in data:
ax.text(initial+offset*c, 0.05, str(i), horizontalalignment='center',
verticalalignment='center', transform=ax.transAxes,fontsize=8)
c=c+1
else:
for rect,i in zip(rects,data):
height = rect.get_height()
ax.text(rect.get_x() + rect.get_width()/2., height,str(i),ha='center', va='bottom')
Which language uses .pde extension?
Bad news I'm afraid (or maybe great news?) : it isn't C code, it's an example of "Processing" - an open source language aimed at programming images. Take a look here
Looks very cool.
What's the best way of scraping data from a website?
You will definitely want to start with a good web scraping framework. Later on you may decide that they are too limiting and you can put together your own stack of libraries but without a lot of scraping experience your design will be much worse than pjscrape or scrapy.
Note: I use the terms crawling and scraping basically interchangeable here. This is a copy of my answer to your Quora question, it's pretty long.
Tools
Get very familiar with either Firebug or Chrome dev tools depending on your preferred browser. This will be absolutely necessary as you browse the site you are pulling data from and map out which urls contain the data you are looking for and what data formats make up the responses.
You will need a good working knowledge of HTTP as well as HTML and will probably want to find a decent piece of man in the middle proxy software. You will need to be able to inspect HTTP requests and responses and understand how the cookies and session information and query parameters are being passed around. Fiddler (http://www.telerik.com/fiddler) and Charles Proxy (http://www.charlesproxy.com/) are popular tools. I use mitmproxy (http://mitmproxy.org/) a lot as I'm more of a keyboard guy than a mouse guy.
Some kind of console/shell/REPL type environment where you can try out various pieces of code with instant feedback will be invaluable. Reverse engineering tasks like this are a lot of trial and error so you will want a workflow that makes this easy.
Language
PHP is basically out, it's not well suited for this task and the library/framework support is poor in this area. Python (Scrapy is a great starting point) and Clojure/Clojurescript (incredibly powerful and productive but a big learning curve) are great languages for this problem. Since you would rather not learn a new language and you already know Javascript I would definitely suggest sticking with JS. I have not used pjscrape but it looks quite good from a quick read of their docs. It's well suited and implements an excellent solution to the problem I describe below.
A note on Regular expressions: DO NOT USE REGULAR EXPRESSIONS TO PARSE HTML. A lot of beginners do this because they are already familiar with regexes. It's a huge mistake, use xpath or css selectors to navigate html and only use regular expressions to extract data from actual text inside an html node. This might already be obvious to you, it becomes obvious quickly if you try it but a lot of people waste a lot of time going down this road for some reason. Don't be scared of xpath or css selectors, they are WAY easier to learn than regexes and they were designed to solve this exact problem.
Javascript-heavy sites
In the old days you just had to make an http request and parse the HTML reponse. Now you will almost certainly have to deal with sites that are a mix of standard HTML HTTP request/responses and asynchronous HTTP calls made by the javascript portion of the target site. This is where your proxy software and the network tab of firebug/devtools comes in very handy. The responses to these might be html or they might be json, in rare cases they will be xml or something else.
There are two approaches to this problem:
The low level approach:
You can figure out what ajax urls the site javascript is calling and what those responses look like and make those same requests yourself. So you might pull the html from http://example.com/foobar and extract one piece of data and then have to pull the json response from http://example.com/api/baz?foo=b... to get the other piece of data. You'll need to be aware of passing the correct cookies or session parameters. It's very rare, but occasionally some required parameters for an ajax call will be the result of some crazy calculation done in the site's javascript, reverse engineering this can be annoying.
The embedded browser approach:
Why do you need to work out what data is in html and what data comes in from an ajax call? Managing all that session and cookie data? You don't have to when you browse a site, the browser and the site javascript do that. That's the whole point.
If you just load the page into a headless browser engine like phantomjs it will load the page, run the javascript and tell you when all the ajax calls have completed. You can inject your own javascript if necessary to trigger the appropriate clicks or whatever is necessary to trigger the site javascript to load the appropriate data.
You now have two options, get it to spit out the finished html and parse it or inject some javascript into the page that does your parsing and data formatting and spits the data out (probably in json format). You can freely mix these two options as well.
Which approach is best?
That depends, you will need to be familiar and comfortable with the low level approach for sure. The embedded browser approach works for anything, it will be much easier to implement and will make some of the trickiest problems in scraping disappear. It's also quite a complex piece of machinery that you will need to understand. It's not just HTTP requests and responses, it's requests, embedded browser rendering, site javascript, injected javascript, your own code and 2-way interaction with the embedded browser process.
The embedded browser is also much slower at scale because of the rendering overhead but that will almost certainly not matter unless you are scraping a lot of different domains. Your need to rate limit your requests will make the rendering time completely negligible in the case of a single domain.
Rate Limiting/Bot behaviour
You need to be very aware of this. You need to make requests to your target domains at a reasonable rate. You need to write a well behaved bot when crawling websites, and that means respecting robots.txt and not hammering the server with requests. Mistakes or negligence here is very unethical since this can be considered a denial of service attack. The acceptable rate varies depending on who you ask, 1req/s is the max that the Google crawler runs at but you are not Google and you probably aren't as welcome as Google. Keep it as slow as reasonable. I would suggest 2-5 seconds between each page request.
Identify your requests with a user agent string that identifies your bot and have a webpage for your bot explaining it's purpose. This url goes in the agent string.
You will be easy to block if the site wants to block you. A smart engineer on their end can easily identify bots and a few minutes of work on their end can cause weeks of work changing your scraping code on your end or just make it impossible. If the relationship is antagonistic then a smart engineer at the target site can completely stymie a genius engineer writing a crawler. Scraping code is inherently fragile and this is easily exploited. Something that would provoke this response is almost certainly unethical anyway, so write a well behaved bot and don't worry about this.
Testing
Not a unit/integration test person? Too bad. You will now have to become one. Sites change frequently and you will be changing your code frequently. This is a large part of the challenge.
There are a lot of moving parts involved in scraping a modern website, good test practices will help a lot. Many of the bugs you will encounter while writing this type of code will be the type that just return corrupted data silently. Without good tests to check for regressions you will find out that you've been saving useless corrupted data to your database for a while without noticing. This project will make you very familiar with data validation (find some good libraries to use) and testing. There are not many other problems that combine requiring comprehensive tests and being very difficult to test.
The second part of your tests involve caching and change detection. While writing your code you don't want to be hammering the server for the same page over and over again for no reason. While running your unit tests you want to know if your tests are failing because you broke your code or because the website has been redesigned. Run your unit tests against a cached copy of the urls involved. A caching proxy is very useful here but tricky to configure and use properly.
You also do want to know if the site has changed. If they redesigned the site and your crawler is broken your unit tests will still pass because they are running against a cached copy! You will need either another, smaller set of integration tests that are run infrequently against the live site or good logging and error detection in your crawling code that logs the exact issues, alerts you to the problem and stops crawling. Now you can update your cache, run your unit tests and see what you need to change.
Legal Issues
The law here can be slightly dangerous if you do stupid things. If the law gets involved you are dealing with people who regularly refer to wget and curl as "hacking tools". You don't want this.
The ethical reality of the situation is that there is no difference between using browser software to request a url and look at some data and using your own software to request a url and look at some data. Google is the largest scraping company in the world and they are loved for it. Identifying your bots name in the user agent and being open about the goals and intentions of your web crawler will help here as the law understands what Google is. If you are doing anything shady, like creating fake user accounts or accessing areas of the site that you shouldn't (either "blocked" by robots.txt or because of some kind of authorization exploit) then be aware that you are doing something unethical and the law's ignorance of technology will be extraordinarily dangerous here. It's a ridiculous situation but it's a real one.
It's literally possible to try and build a new search engine on the up and up as an upstanding citizen, make a mistake or have a bug in your software and be seen as a hacker. Not something you want considering the current political reality.
Who am I to write this giant wall of text anyway?
I've written a lot of web crawling related code in my life. I've been doing web related software development for more than a decade as a consultant, employee and startup founder. The early days were writing perl crawlers/scrapers and php websites. When we were embedding hidden iframes loading csv data into webpages to do ajax before Jesse James Garrett named it ajax, before XMLHTTPRequest was an idea. Before jQuery, before json. I'm in my mid-30's, that's apparently considered ancient for this business.
I've written large scale crawling/scraping systems twice, once for a large team at a media company (in Perl) and recently for a small team as the CTO of a search engine startup (in Python/Javascript). I currently work as a consultant, mostly coding in Clojure/Clojurescript (a wonderful expert language in general and has libraries that make crawler/scraper problems a delight)
I've written successful anti-crawling software systems as well. It's remarkably easy to write nigh-unscrapable sites if you want to or to identify and sabotage bots you don't like.
I like writing crawlers, scrapers and parsers more than any other type of software. It's challenging, fun and can be used to create amazing things.
Git conflict markers
The line (or lines) between the lines beginning <<<<<<< and ====== here:
<<<<<<< HEAD:file.txt
Hello world
=======
... is what you already had locally - you can tell because HEAD points to your current branch or commit. The line (or lines) between the lines beginning ======= and >>>>>>>:
=======
Goodbye
>>>>>>> 77976da35a11db4580b80ae27e8d65caf5208086:file.txt
... is what was introduced by the other (pulled) commit, in this case 77976da35a11. That is the object name (or "hash", "SHA1sum", etc.) of the commit that was merged into HEAD. All objects in git, whether they're commits (version), blobs (files), trees (directories) or tags have such an object name, which identifies them uniquely based on their content.
R Plotting confidence bands with ggplot
require(ggplot2)
require(nlme)
set.seed(101)
mp <-data.frame(year=1990:2010)
N <- nrow(mp)
mp <- within(mp,
{
wav <- rnorm(N)*cos(2*pi*year)+rnorm(N)*sin(2*pi*year)+5
wow <- rnorm(N)*wav+rnorm(N)*wav^3
})
m01 <- gls(wow~poly(wav,3), data=mp, correlation = corARMA(p=1))
Get fitted values (the same as m01$fitted)
fit <- predict(m01)
Normally we could use something like predict(...,se.fit=TRUE) to get the confidence intervals on the prediction, but gls doesn't provide this capability. We use a recipe similar to the one shown at http://glmm.wikidot.com/faq :
V <- vcov(m01)
X <- model.matrix(~poly(wav,3),data=mp)
se.fit <- sqrt(diag(X %*% V %*% t(X)))
Put together a "prediction frame":
predframe <- with(mp,data.frame(year,wav,
wow=fit,lwr=fit-1.96*se.fit,upr=fit+1.96*se.fit))
Now plot with geom_ribbon
(p1 <- ggplot(mp, aes(year, wow))+
geom_point()+
geom_line(data=predframe)+
geom_ribbon(data=predframe,aes(ymin=lwr,ymax=upr),alpha=0.3))
It's easier to see that we got the right answer if we plot against wav rather than year:
(p2 <- ggplot(mp, aes(wav, wow))+
geom_point()+
geom_line(data=predframe)+
geom_ribbon(data=predframe,aes(ymin=lwr,ymax=upr),alpha=0.3))
It would be nice to do the predictions with more resolution, but it's a little tricky to do this with the results of poly() fits -- see ?makepredictcall.
Get value of a string after last slash in JavaScript
When I know the string is going to be reasonably short then I use the following one liner... (remember to escape backslashes)
// if str is C:\windows\file system\path\picture name.jpg
alert( str.split('\\').pop() );
alert pops up with picture name.jpg
Which version of MVC am I using?
In Mvc You can do it by opening Web.config file it comes under bottom of your project file
Accessing dict_keys element by index in Python3
In many cases, this may be an XY Problem. Why are you indexing your dictionary keys by position? Do you really need to? Until recently, dictionaries were not even ordered in Python, so accessing the first element was arbitrary.
I just translated some Python 2 code to Python 3:
keys = d.keys()
for (i, res) in enumerate(some_list):
k = keys[i]
# ...
which is not pretty, but not very bad either. At first, I was about to replace it by the monstrous
k = next(itertools.islice(iter(keys), i, None))
before I realised this is all much better written as
for (k, res) in zip(d.keys(), some_list):
which works just fine.
I believe that in many other cases, indexing dictionary keys by position can be avoided. Although dictionaries are ordered in Python 3.7, relying on that is not pretty. The code above only works because the contents of some_list had been recently produced from the contents of d.
Have a hard look at your code if you really need to access a disk_keys element by index. Perhaps you don't need to.
Remove elements from collection while iterating
Old Timer Favorite (it still works):
List<String> list;
for(int i = list.size() - 1; i >= 0; --i)
{
if(list.get(i).contains("bad"))
{
list.remove(i);
}
}
Benefits:
- It only iterates over the list once
- No extra objects created, or other unneeded complexity
- No problems with trying to use the index of a removed item, because... well, think about it!
How do you launch the JavaScript debugger in Google Chrome?
Try adding this to your source:
debugger;
It works in most, if not all browsers. Just place it somewhere in your code, and it will act like a breakpoint.
AngularJS: Service vs provider vs factory
This is very confusing part for newbie and I have tried to clarify it in easy words
AngularJS Service: is used for sharing utility functions with the service reference in the controller. Service is singleton in nature so for one service only one instance is created in the browser and the same reference is used throughout the page.
In the service, we create function names as property with this object.
AngularJS Factory: the purpose of Factory is also same as Service however in this case we create a new object and add functions as properties of this object and at the end we return this object.
AngularJS Provider: the purpose of this is again same however Provider gives the output of it's $get function.
Defining and using Service, Factory and Provider are explained at http://www.dotnetfunda.com/articles/show/3156/difference-between-angularjs-service-factory-and-provider
How can I get the class name from a C++ object?
Just write simple template:
template<typename T>
const char* getClassName(T) {
return typeid(T).name();
}
struct A {} a;
void main() {
std::cout << getClassName(a);
}
Use Mockito to mock some methods but not others
According to docs :
Foo mock = mock(Foo.class, CALLS_REAL_METHODS);
// this calls the real implementation of Foo.getSomething()
value = mock.getSomething();
when(mock.getSomething()).thenReturn(fakeValue);
// now fakeValue is returned
value = mock.getSomething();
How to make JQuery-AJAX request synchronous
try this
the solution is, work with callbacks like this
$(function() {
var jForm = $('form[name=form]');
var jPWField = $('#employee_password');
function getCheckedState() {
return jForm.data('checked_state');
};
function setChecked(s) {
jForm.data('checked_state', s);
};
jPWField.change(function() {
//reset checked thing
setChecked(null);
}).trigger('change');
jForm.submit(function(){
switch(getCheckedState()) {
case 'valid':
return true;
case 'invalid':
//invalid, don submit
return false;
default:
//make your check
var password = $.trim(jPWField.val());
$.ajax({
type: "POST",
async: "false",
url: "checkpass.php",
data: {
"password": $.trim(jPWField.val);
}
success: function(html) {
var arr=$.parseJSON(html);
setChecked(arr == "Successful" ? 'valid': 'invalid');
//submit again
jForm.submit();
}
});
return false;
}
});
});
How to get the python.exe location programmatically?
I think it depends on how you installed python. Note that you can have multiple installs of python, I do on my machine. However, if you install via an msi of a version of python 2.2 or above, I believe it creates a registry key like so:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\Python.exe
which gives this value on my machine:
C:\Python25\Python.exe
You just read the registry key to get the location.
However, you can install python via an xcopy like model that you can have in an arbitrary place, and you just have to know where it is installed.
BAT file to map to network drive without running as admin
I just figured it out! What I did was I created the batch file like I had it originally:
net use P: "\\server\foldername\foldername"
I then saved it to the desktop and right clicked the properties and checked run as administrator. I then copied the file to C:\Users\"TheUser"\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup
Where "TheUser" was the desired user I wanted to add it to.
html form - make inputs appear on the same line
You can make a class for each label and inside it put:
display: inline-block;
And width the value that you need.
Iterate over values of object
In the sense I think you intended, in ES5 or ES2015, no, not without some work on your part.
In ES2016, probably with object.values.
Mind you Arrays in JavaScript are effectively a map from an integer to a value, and the values in JavaScript arrays can be enumerated directly.
['foo', 'bar'].forEach(v => console.log(v)); // foo bar
Also, in ES2015, you can make an object iterable by placing a function on a property with the name of Symbol.iterator:
var obj = {
foo: '1',
bar: '2',
bam: '3',
bat: '4',
};
obj[Symbol.iterator] = iter.bind(null, obj);
function* iter(o) {
var keys = Object.keys(o);
for (var i=0; i<keys.length; i++) {
yield o[keys[i]];
}
}
for(var v of obj) { console.log(v); } // '1', '2', '3', '4'
Also, per other answers, there are other built-ins that provide the functionality you want, like Map (but not WeakMap because it is not iterable) and Set for example (but these are not present in all browsers yet).
How to convert a DataTable to a string in C#?
public static string DataTable2String(DataTable dataTable)
{
StringBuilder sb = new StringBuilder();
if (dataTable != null)
{
string seperator = " | ";
#region get min length for columns
Hashtable hash = new Hashtable();
foreach (DataColumn col in dataTable.Columns)
hash[col.ColumnName] = col.ColumnName.Length;
foreach (DataRow row in dataTable.Rows)
for (int i = 0; i < row.ItemArray.Length; i++)
if (row[i] != null)
if (((string)row[i]).Length > (int)hash[dataTable.Columns[i].ColumnName])
hash[dataTable.Columns[i].ColumnName] = ((string)row[i]).Length;
int rowLength = (hash.Values.Count + 1) * seperator.Length;
foreach (object o in hash.Values)
rowLength += (int)o;
#endregion get min length for columns
sb.Append(new string('=', (rowLength - " DataTable ".Length) / 2));
sb.Append(" DataTable ");
sb.AppendLine(new string('=', (rowLength - " DataTable ".Length) / 2));
if (!string.IsNullOrEmpty(dataTable.TableName))
sb.AppendLine(String.Format("{0,-" + rowLength + "}", String.Format("{0," + ((rowLength + dataTable.TableName.Length) / 2).ToString() + "}", dataTable.TableName)));
#region write values
foreach (DataColumn col in dataTable.Columns)
sb.Append(seperator + String.Format("{0,-" + hash[col.ColumnName] + "}", col.ColumnName));
sb.AppendLine(seperator);
sb.AppendLine(new string('-', rowLength));
foreach (DataRow row in dataTable.Rows)
{
for (int i = 0; i < row.ItemArray.Length; i++)
{
sb.Append(seperator + String.Format("{0," + hash[dataTable.Columns[i].ColumnName] + "}", row[i]));
if (i == row.ItemArray.Length - 1)
sb.AppendLine(seperator);
}
}
#endregion write values
sb.AppendLine(new string('=', rowLength));
}
else
sb.AppendLine("================ DataTable is NULL ================");
return sb.ToString();
}
output:
======================= DataTable =======================
MyTable
| COL1 | COL2 | COL3 1000000ng name |
----------------------------------------------------------
| 1 | 2 | 3 |
| abc | Dienstag, 12. März 2013 | xyz |
| Have | a nice | day! |
==========================================================
in angularjs how to access the element that triggered the event?
if you wanna ng-model value, if you can write like this in the triggered event: $scope.searchText
What Are The Best Width Ranges for Media Queries
Try this one with retina display
/* Smartphones (portrait and landscape) ----------- */
@media only screen
and (min-device-width : 320px)
and (max-device-width : 480px) {
/* Styles */
}
/* Smartphones (landscape) ----------- */
@media only screen
and (min-width : 321px) {
/* Styles */
}
/* Smartphones (portrait) ----------- */
@media only screen
and (max-width : 320px) {
/* Styles */
}
/* iPads (portrait and landscape) ----------- */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px) {
/* Styles */
}
/* iPads (landscape) ----------- */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px)
and (orientation : landscape) {
/* Styles */
}
/* iPads (portrait) ----------- */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px)
and (orientation : portrait) {
/* Styles */
}
/* Desktops and laptops ----------- */
@media only screen
and (min-width : 1224px) {
/* Styles */
}
/* Large screens ----------- */
@media only screen
and (min-width : 1824px) {
/* Styles */
}
/* iPhone 4 ----------- */
@media
only screen and (-webkit-min-device-pixel-ratio : 1.5),
only screen and (min-device-pixel-ratio : 1.5) {
/* Styles */
}
Update
/* Smartphones (portrait and landscape) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-width: 480px) {
/* Styles */
}
/* Smartphones (landscape) ----------- */
@media only screen and (min-width: 321px) {
/* Styles */
}
/* Smartphones (portrait) ----------- */
@media only screen and (max-width: 320px) {
/* Styles */
}
/* iPads (portrait and landscape) ----------- */
@media only screen and (min-device-width: 768px) and (max-device-width: 1024px) {
/* Styles */
}
/* iPads (landscape) ----------- */
@media only screen and (min-device-width: 768px) and (max-device-width: 1024px) and (orientation: landscape) {
/* Styles */
}
/* iPads (portrait) ----------- */
@media only screen and (min-device-width: 768px) and (max-device-width: 1024px) and (orientation: portrait) {
/* Styles */
}
/* iPad 3 (landscape) ----------- */
@media only screen and (min-device-width: 768px) and (max-device-width: 1024px) and (orientation: landscape) and (-webkit-min-device-pixel-ratio: 2) {
/* Styles */
}
/* iPad 3 (portrait) ----------- */
@media only screen and (min-device-width: 768px) and (max-device-width: 1024px) and (orientation: portrait) and (-webkit-min-device-pixel-ratio: 2) {
/* Styles */
}
/* Desktops and laptops ----------- */
@media only screen and (min-width: 1224px) {
/* Styles */
}
/* Large screens ----------- */
@media only screen and (min-width: 1824px) {
/* Styles */
}
/* iPhone 4 (landscape) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-width: 480px) and (orientation: landscape) and (-webkit-min-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 4 (portrait) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-width: 480px) and (orientation: portrait) and (-webkit-min-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 5 (landscape) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 568px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 5 (portrait) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 568px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 6 (landscape) ----------- */
@media only screen and (min-device-width: 375px) and (max-device-height: 667px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 6 (portrait) ----------- */
@media only screen and (min-device-width: 375px) and (max-device-height: 667px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 6+ (landscape) ----------- */
@media only screen and (min-device-width: 414px) and (max-device-height: 736px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* iPhone 6+ (portrait) ----------- */
@media only screen and (min-device-width: 414px) and (max-device-height: 736px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* Samsung Galaxy S3 (landscape) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* Samsung Galaxy S3 (portrait) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 2) {
/* Styles */
}
/* Samsung Galaxy S4 (landscape) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 3) {
/* Styles */
}
/* Samsung Galaxy S4 (portrait) ----------- */
@media only screen and (min-device-width: 320px) and (max-device-height: 640px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 3) {
/* Styles */
}
/* Samsung Galaxy S5 (landscape) ----------- */
@media only screen and (min-device-width: 360px) and (max-device-height: 640px) and (orientation: landscape) and (-webkit-device-pixel-ratio: 3) {
/* Styles */
}
/* Samsung Galaxy S5 (portrait) ----------- */
@media only screen and (min-device-width: 360px) and (max-device-height: 640px) and (orientation: portrait) and (-webkit-device-pixel-ratio: 3) {
/* Styles */
}
jQuery onclick toggle class name
It can even be made dependent to another attribute changes. like this:
$('.classA').toggleClass('classB', $('input').prop('disabled'));
In this case, classB are added each time the input is disabled
how can I display tooltip or item information on mouse over?
Use the title attribute while alt is important for SEO stuff.
How do I append to a table in Lua
foo = {}
foo[#foo+1]="bar"
foo[#foo+1]="baz"
This works because the # operator computes the length of the list. The empty list has length 0, etc.
If you're using Lua 5.3+, then you can do almost exactly what you wanted:
foo = {}
setmetatable(foo, { __shl = function (t,v) t[#t+1]=v end })
_= foo << "bar"
_= foo << "baz"
Expressions are not statements in Lua and they need to be used somehow.
HTTP post XML data in C#
AlliterativeAlice's example helped me tremendously. In my case, though, the server I was talking to didn't like having single quotes around utf-8 in the content type. It failed with a generic "Server Error" and it took hours to figure out what it didn't like:
request.ContentType = "text/xml; encoding=utf-8";
Java 8 Stream and operation on arrays
You can turn an array into a stream by using Arrays.stream():
int[] ns = new int[] {1,2,3,4,5};
Arrays.stream(ns);
Once you've got your stream, you can use any of the methods described in the documentation, like sum() or whatever. You can map or filter like in Python by calling the relevant stream methods with a Lambda function:
Arrays.stream(ns).map(n -> n * 2);
Arrays.stream(ns).filter(n -> n % 4 == 0);
Once you're done modifying your stream, you then call toArray() to convert it back into an array to use elsewhere:
int[] ns = new int[] {1,2,3,4,5};
int[] ms = Arrays.stream(ns).map(n -> n * 2).filter(n -> n % 4 == 0).toArray();
Deleting multiple elements from a list
You can use enumerate and remove the values whose index matches the indices you want to remove:
indices = 0, 2
somelist = [i for j, i in enumerate(somelist) if j not in indices]
What MySQL data type should be used for Latitude/Longitude with 8 decimal places?
You can set your data-type as signed integer. When you storage coordinates to SQL you can set as lat*10000000 and long*10000000. And when you selecting with distance/radius you will divide storage coordinates to 10000000. I was test it with 300K rows, query response time is good. ( 2 x 2.67GHz CPU, 2 GB RAM, MySQL 5.5.49 )
Java Round up Any Number
10 years later but that problem still caught me.
So this is the answer to those that are too late as me.
This does not work
int b = (int) Math.ceil(a / 100);
Cause the result a / 100 turns out to be an integer and it's rounded so Math.ceil
can't do anything about it.
You have to avoid the rounded operation with this
int b = (int) Math.ceil((float) a / 100);
Now it works.
How to lay out Views in RelativeLayout programmatically?
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
final RelativeLayout relativeLayout = new RelativeLayout(this);
final TextView tv1 = new TextView(this);
tv1.setText("tv1 is here");
// Setting an ID is mandatory.
tv1.setId(View.generateViewId());
relativeLayout.addView(tv1);
final TextView tv2 = new TextView(this);
tv2.setText("tv2 is here");
// We are defining layout params for tv2 which will be added to its parent relativelayout.
// The type of the LayoutParams depends on the parent type.
RelativeLayout.LayoutParams tv2LayoutParams = new RelativeLayout.LayoutParams(
RelativeLayout.LayoutParams.WRAP_CONTENT,
RelativeLayout.LayoutParams.WRAP_CONTENT);
//Also, we want tv2 to appear below tv1, so we are adding rule to tv2LayoutParams.
tv2LayoutParams.addRule(RelativeLayout.BELOW, tv1.getId());
//Now, adding the child view tv2 to relativelayout, and setting tv2LayoutParams to be set on view tv2.
relativeLayout.addView(tv2);
tv2.setLayoutParams(tv2LayoutParams);
//Or we can combined the above two steps in one line of code
//relativeLayout.addView(tv2, tv2LayoutParams);
this.setContentView(relativeLayout);
}
}
Digital Certificate: How to import .cer file in to .truststore file using?
The way you import a .cer file into the trust store is the same way you'd import a .crt file from say an export from Firefox.
You do not have to put an alias and the password of the keystore, you can just type:
keytool -v -import -file somefile.crt -alias somecrt -keystore my-cacerts
Preferably use the cacerts file that is already in your Java installation (jre\lib\security\cacerts) as it contains secure "popular" certificates.
Update regarding the differences of cer and crt (just to clarify) According to Apache with SSL - How to convert CER to CRT certificates? and user @Spawnrider
CER is a X.509 certificate in binary form, DER encoded.
CRT is a binary X.509 certificate, encapsulated in text (base-64) encoding.
It is not the same encoding.
How to use img src in vue.js?
Try this:
<img v-bind:src="'/media/avatars/' + joke.avatar" />
Don't forget single quote around your path string. also in your data check you have correctly defined image variable.
joke: {
avatar: 'image.jpg'
}
A working demo here: http://jsbin.com/pivecunode/1/edit?html,js,output
Include files from parent or other directory
Had same issue earlier solved like this :
include('/../includes/config.php'); //note '/' appearing before '../includes/config.php'
Comparing double values in C#
Taking a tip from the Java code base, try using .CompareTo and test for the zero comparison. This assumes the .CompareTo function takes in to account floating point equality in an accurate manner. For instance,
System.Math.PI.CompareTo(System.Math.PI) == 0
This predicate should return true.
Difference between frontend, backend, and middleware in web development
In terms of networking and security, the Backend is by far the most (should be) secure node.
The middle-end portion, usually being a web server, will be somewhat in the wild and cut off in many respects from a company's network. The middle-end node is usually placed in the DMZ and segmented from the network with firewall settings. Most of the server-side code parsing of web pages is handled on the middle-end web server.
Getting to the backend means going through the middle-end, which has a carefully crafted set of rules allowing/disallowing access to the vital nummies which are stored on the database (backend) server.
NodeJS: How to get the server's port?
Express 4.x answer:
Express 4.x (per Tien Do's answer below), now treats app.listen() as an asynchronous operation, so listener.address() will only return data inside of app.listen()'s callback:
var app = require('express')();
var listener = app.listen(8888, function(){
console.log('Listening on port ' + listener.address().port); //Listening on port 8888
});
Express 3 answer:
I think you are looking for this(express specific?):
console.log("Express server listening on port %d", app.address().port)
You might have seen this(bottom line), when you create directory structure from express command:
alfred@alfred-laptop:~/node$ express test4
create : test4
create : test4/app.js
create : test4/public/images
create : test4/public/javascripts
create : test4/logs
create : test4/pids
create : test4/public/stylesheets
create : test4/public/stylesheets/style.less
create : test4/views/partials
create : test4/views/layout.jade
create : test4/views/index.jade
create : test4/test
create : test4/test/app.test.js
alfred@alfred-laptop:~/node$ cat test4/app.js
/**
* Module dependencies.
*/
var express = require('express');
var app = module.exports = express.createServer();
// Configuration
app.configure(function(){
app.set('views', __dirname + '/views');
app.use(express.bodyDecoder());
app.use(express.methodOverride());
app.use(express.compiler({ src: __dirname + '/public', enable: ['less'] }));
app.use(app.router);
app.use(express.staticProvider(__dirname + '/public'));
});
app.configure('development', function(){
app.use(express.errorHandler({ dumpExceptions: true, showStack: true }));
});
app.configure('production', function(){
app.use(express.errorHandler());
});
// Routes
app.get('/', function(req, res){
res.render('index.jade', {
locals: {
title: 'Express'
}
});
});
// Only listen on $ node app.js
if (!module.parent) {
app.listen(3000);
console.log("Express server listening on port %d", app.address().port)
}