How do you overcome the HTML form nesting limitation?
In response to a question posted by Yar in a comment to his own answer, I present some JavaScript which will resize an iframe. For the case of a form button, it is safe to assume the iframe will be on the same domain. This is the code I use. You will have to alter the maths/constants for your own site:
function resizeIFrame(frame)
{
try {
innerDoc = ('contentDocument' in frame) ? frame.contentDocument : frame.contentWindow.document;
if('style' in frame) {
frame.style.width = Math.min(755, Math.ceil(innerDoc.body.scrollWidth)) + 'px';
frame.style.height = Math.ceil(innerDoc.body.scrollHeight) + 'px';
} else {
frame.width = Math.ceil(innerDoc.body.scrollWidth);
frame.height = Math.ceil(innerDoc.body.scrollHeight);
}
} catch(err) {
window.status = err.message;
}
}
Then call it like this:
<iframe ... frameborder="0" onload="if(window.parent && window.parent.resizeIFrame){window.parent.resizeIFrame(this);}"></iframe>
Use Mockito to mock some methods but not others
Partial mocking of a class is also supported via Spy in mockito
List list = new LinkedList();
List spy = spy(list);
//optionally, you can stub out some methods:
when(spy.size()).thenReturn(100);
//using the spy calls real methods
spy.add("one");
spy.add("two");
//size() method was stubbed - 100 is printed
System.out.println(spy.size());
Check the 1.10.19
and 2.7.22
docs for detailed explanation.
java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
This problem happens when a process tries to manipulate an Activity whose onStop()
has been called. It's not necessarily tied to fragment transaction but also other methods like onBackPressed().
In addition to AsyncTask, another source of such problem is the misplacement of bus pattern's subscription. Usually Event Bus or RxBus's subscription is registered during Activity's onCreate and de-registered in onDestroy. If a new Activity starts and publishes an event intercepted by subscribers from the previous Activity then it may produce this error. If this happens then one solution is to move subscription registration and de-registration to onStart()
and onStop()
.
Difference between `constexpr` and `const`
According to book of "The C++ Programming Language 4th Editon" by Bjarne Stroustrup
• const: meaning roughly ‘‘I promise not to change this value’’ (§7.5). This is used primarily
to specify interfaces, so that data can be passed to functions without fear of it being modified.
The compiler enforces the promise made by const.
• constexpr: meaning roughly ‘‘to be evaluated at compile time’’ (§10.4). This is used primarily to specify constants, to allow
For example:
const int dmv = 17; // dmv is a named constant
int var = 17; // var is not a constant
constexpr double max1 = 1.4*square(dmv); // OK if square(17) is a constant expression
constexpr double max2 = 1.4*square(var); // error : var is not a constant expression
const double max3 = 1.4*square(var); //OK, may be evaluated at run time
double sum(const vector<double>&); // sum will not modify its argument (§2.2.5)
vector<double> v {1.2, 3.4, 4.5}; // v is not a constant
const double s1 = sum(v); // OK: evaluated at run time
constexpr double s2 = sum(v); // error : sum(v) not constant expression
For a function to be usable in a constant expression, that is, in an expression that will be evaluated
by the compiler, it must be defined constexpr.
For example:
constexpr double square(double x) { return x*x; }
To be constexpr, a function must be rather simple: just a return-statement computing a value. A
constexpr function can be used for non-constant arguments, but when that is done the result is not a
constant expression. We allow a constexpr function to be called with non-constant-expression arguments
in contexts that do not require constant expressions, so that we don’t hav e to define essentially
the same function twice: once for constant expressions and once for variables.
In a few places, constant expressions are required by language rules (e.g., array bounds (§2.2.5,
§7.3), case labels (§2.2.4, §9.4.2), some template arguments (§25.2), and constants declared using
constexpr). In other cases, compile-time evaluation is important for performance. Independently of
performance issues, the notion of immutability (of an object with an unchangeable state) is an
important design concern (§10.4).
How do I get a substring of a string in Python?
I would like to add two points to the discussion:
You can use None
instead on an empty space to specify "from the start" or "to the end":
'abcde'[2:None] == 'abcde'[2:] == 'cde'
This is particularly helpful in functions, where you can't provide an empty space as an argument:
def substring(s, start, end):
"""Remove `start` characters from the beginning and `end`
characters from the end of string `s`.
Examples
--------
>>> substring('abcde', 0, 3)
'abc'
>>> substring('abcde', 1, None)
'bcde'
"""
return s[start:end]
Python has slice objects:
idx = slice(2, None)
'abcde'[idx] == 'abcde'[2:] == 'cde'
Update an outdated branch against master in a Git repo
Update the master branch, which you need to do regardless.
Then, one of:
Rebase the old branch against the master branch. Solve the merge conflicts during rebase, and the result will be an up-to-date branch that merges cleanly against master.
Merge your branch into master, and resolve the merge conflicts.
Merge master into your branch, and resolve the merge conflicts. Then, merging from your branch into master should be clean.
None of these is better than the other, they just have different trade-off patterns.
I would use the rebase approach, which gives cleaner overall results to later readers, in my opinion, but that is nothing aside from personal taste.
To rebase and keep the branch you would:
git checkout <branch> && git rebase <target>
In your case, check out the old branch, then
git rebase master
to get it rebuilt against master.
Difference between $.ajax() and $.get() and $.load()
$.ajax()
is the most configurable one, where you get fine grained control over HTTP headers and such. You're also able to get direct access to the XHR-object using this method. Slightly more fine-grained error-handling is also provided. Can therefore be more complicated and often unecessary, but sometimes very useful. You have to deal with the returned data yourself with a callback.
$.get()
is just a shorthand for $.ajax()
but abstracts some of the configurations away, setting reasonable default values for what it hides from you. Returns the data to a callback. It only allows GET-requests so is accompanied by the $.post()
function for similar abstraction, only for POST
.load()
is similar to $.get()
but adds functionality which allows you to define where in the document the returned data is to be inserted. Therefore really only usable when the call only will result in HTML. It is called slightly differently than the other, global, calls, as it is a method tied to a particular jQuery-wrapped DOM element. Therefore, one would do: $('#divWantingContent').load(...)
It should be noted that all $.get()
, $.post()
, .load()
are all just wrappers for $.ajax()
as it's called internally.
More details in the Ajax-documentation of jQuery: http://api.jquery.com/category/ajax/
How to use cURL to get jSON data and decode the data?
to get the object you do not need to use cURL (you are loading another dll into memory and have another dependency, unless you really need curl I'd stick with built in php functions), you can use one simple php file_get_contents(url) function:
http://il1.php.net/manual/en/function.file-get-contents.php
$unparsed_json = file_get_contents("api.php?action=getThreads&hash=123fajwersa&node_id=4&order_by=post_date&order=desc&limit=1&grab_content&content_limit=1");
$json_object = json_decode($unparsed_json);
then json_decode() parses JSON into a PHP object, or an array if you pass true
to the second parameter.
http://php.net/manual/en/function.json-decode.php
For example:
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json)); // Object
var_dump(json_decode($json, true)); // Associative array
How can I make a checkbox readonly? not disabled?
Make a fake checkbox with no name and value, force the value in an hidden field:
<input type="checkbox" disabled="disabled" checked="checked">
<input type="hidden" name="name" value="true">
Note: if you put name and value in the checkbox, it will be anyway overwritten by the input with the same name
Remove last specific character in a string c#
Dim psValue As String = "1,5,12,34,123,12"
psValue = psValue.Substring(0, psValue.LastIndexOf(","))
output:
1,5,12,34,123
Determine when a ViewPager changes pages
For ViewPager2,
viewPager.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback() {
override fun onPageSelected(position: Int) {
super.onPageSelected(position)
}
})
where OnPageChangeCallback
is a static class with three methods:
onPageScrolled(int position, float positionOffset, @Px int positionOffsetPixels),
onPageSelected(int position),
onPageScrollStateChanged(@ScrollState int state)
How to make a gap between two DIV within the same column
Please pay attention to the comments after the 2 lines.
.box1 {
display: block;
padding: 10px;
margin-bottom: 100px; /* SIMPLY SET THIS PROPERTY AS MUCH AS YOU WANT. This changes the space below box1 */
text-align: justify;
}
.box2 {
display: block;
padding: 10px;
text-align: justify;
margin-top: 100px; /* OR ADD THIS LINE AND SET YOUR PROPER SPACE as the space above box2 */
}
Multi-Line Comments in Ruby?
Despite the existence of =begin
and =end
, the normal and a more correct way to comment is to use #
's on each line. If you read the source of any ruby library, you will see that this is the way multi-line comments are done in almost all cases.
'node' is not recognized as an internal or external command
Nodejs's installation adds nodejs to the path in the environment properties incorrectly.
By default it adds the following to the path:
C:\Program Files\nodejs\
The ending \
is unnecessary. Remove the \
and everything will be beautiful again.
How to find topmost view controller on iOS
I am thinking that perhaps one thing is being overlooked here. Perhaps it is better to pass the parent viewController into the function that is using the viewController. If you are fishing around in the view hierarchy to find the top view controller that it is probably violating separation of the Model layer and UI layer and is a code smell. Just pointing this out, I did the same, then realized it was much simpler just to pass it in to function, by having the model operation return to the UI layer where I have a reference to the view controller.
Copy an entire worksheet to a new worksheet in Excel 2010
I really liked @brettdj's code, but then I found that when I added additional code to edit the copy, it overwrote my original sheet instead. I've tweaked his answer so that further code pointed at ws1
will affect the new sheet rather than the original.
Sub Test()
Dim ws1 as Worksheet
ThisWorkbook.Worksheets("Master").Copy
Set ws1 = ThisWorkbook.Worksheets("Master (2)")
End Sub
The relationship could not be changed because one or more of the foreign-key properties is non-nullable
I just had the same error.
I have two tables with a parent child relationship, but I configured a "on delete cascade" on the foreign key column in the table definition of the child table.
So when I manually delete the parent row (via SQL) in the database it will automatically delete the child rows.
However this did not work in EF, the error described in this thread showed up.
The reason for this was, that in my entity data model (edmx file) the properties of the association between the parent and the child table were not correct.
The End1 OnDelete
option was configured to be none
("End1" in my model is the end which has a multiplicity of 1).
I manually changed the End1 OnDelete
option to Cascade
and than it worked.
I do not know why EF is not able to pick this up, when I update the model from the database (I have a database first model).
For completeness, this is how my code to delete looks like:
public void Delete(int id)
{
MyType myObject = _context.MyTypes.Find(id);
_context.MyTypes.Remove(myObject);
_context.SaveChanges();
}
If I hadn´t a cascade delete defined, I would have to delete the child rows manually before deleting the parent row.
How do I find the mime-type of a file with php?
function get_mime($file) {
if (function_exists("finfo_file")) {
$finfo = finfo_open(FILEINFO_MIME_TYPE); // return mime type ala mimetype extension
$mime = finfo_file($finfo, $file);
finfo_close($finfo);
return $mime;
} else if (function_exists("mime_content_type")) {
return mime_content_type($file);
} else if (!stristr(ini_get("disable_functions"), "shell_exec")) {
// http://stackoverflow.com/a/134930/1593459
$file = escapeshellarg($file);
$mime = shell_exec("file -bi " . $file);
return $mime;
} else {
return false;
}
}
For me, nothing of this does work - mime_content_type
is deprecated, finfo
is not installed, and shell_exec
is not allowed.
$.widget is not a function
Place your widget.js after core.js, but before any other jquery that calls the widget.js file. (Example: draggable.js) Precedence (order) matters in what javascript/jquery can 'see'. Always position helper code before the code that uses the helper code.
Getting Excel to refresh data on sheet from within VBA
After a data connection update, some UDF's were not executing. Using a subroutine, I was trying to recalcuate a single column with:
Sheets("mysheet").Columns("D").Calculate
But above statement had no effect. None of above solutions helped, except kambeeks suggestion to replace formulas worked and was fast if manual recalc turned on during update. Below code solved my problem, even if not exactly responsible to OP "kluge" comment, it provided a fast/reliable solution to force recalculation of user-specified cells.
Application.Calculation = xlManual
DoEvents
For Each mycell In Sheets("mysheet").Range("D9:D750").Cells
mycell.Formula = mycell.Formula
Next
DoEvents
Application.Calculation = xlAutomatic
How to tar certain file types in all subdirectories?
One method is:
tar -cf my_archive.tar $( find -name "*.php" -or -name "*.html" )
There are some caveats with this method however:
- It will fail if there are any files or directories with spaces in them, and
- it will fail if there are so many files that the maximum command line length is full.
A workaround to these could be to output the contents of the find command into a file, and then use the "-T, --files-from FILE" option to tar.
R: Plotting a 3D surface from x, y, z
rgl
is great, but takes a bit of experimentation to get the axes right.
If you have a lot of points, why not take a random sample from them, and then plot the resulting surface. You can add several surfaces all based on samples from the same data to see if the process of sampling is horribly affecting your data.
So, here is a pretty horrible function but it does what I think you want it to do (but without the sampling). Given a matrix (x, y, z) where z is the heights it will plot both the points and also a surface. Limitations are that there can only be one z for each (x,y) pair. So planes which loop back over themselves will cause problems.
The plot_points = T
will plot the individual points from which the surface is made - this is useful to check that the surface and the points actually meet up. The plot_contour = T
will plot a 2d contour plot below the 3d visualization. Set colour to rainbow
to give pretty colours, anything else will set it to grey, but then you can alter the function to give a custom palette. This does the trick for me anyway, but I'm sure that it can be tidied up and optimized. The verbose = T
prints out a lot of output which I use to debug the function as and when it breaks.
plot_rgl_model_a <- function(fdata, plot_contour = T, plot_points = T,
verbose = F, colour = "rainbow", smoother = F){
## takes a model in long form, in the format
## 1st column x
## 2nd is y,
## 3rd is z (height)
## and draws an rgl model
## includes a contour plot below and plots the points in blue
## if these are set to TRUE
# note that x has to be ascending, followed by y
if (verbose) print(head(fdata))
fdata <- fdata[order(fdata[, 1], fdata[, 2]), ]
if (verbose) print(head(fdata))
##
require(reshape2)
require(rgl)
orig_names <- colnames(fdata)
colnames(fdata) <- c("x", "y", "z")
fdata <- as.data.frame(fdata)
## work out the min and max of x,y,z
xlimits <- c(min(fdata$x, na.rm = T), max(fdata$x, na.rm = T))
ylimits <- c(min(fdata$y, na.rm = T), max(fdata$y, na.rm = T))
zlimits <- c(min(fdata$z, na.rm = T), max(fdata$z, na.rm = T))
l <- list (x = xlimits, y = ylimits, z = zlimits)
xyz <- do.call(expand.grid, l)
if (verbose) print(xyz)
x_boundaries <- xyz$x
if (verbose) print(class(xyz$x))
y_boundaries <- xyz$y
if (verbose) print(class(xyz$y))
z_boundaries <- xyz$z
if (verbose) print(class(xyz$z))
if (verbose) print(paste(x_boundaries, y_boundaries, z_boundaries, sep = ";"))
# now turn fdata into a wide format for use with the rgl.surface
fdata[, 2] <- as.character(fdata[, 2])
fdata[, 3] <- as.character(fdata[, 3])
#if (verbose) print(class(fdata[, 2]))
wide_form <- dcast(fdata, y ~ x, value_var = "z")
if (verbose) print(head(wide_form))
wide_form_values <- as.matrix(wide_form[, 2:ncol(wide_form)])
if (verbose) print(wide_form_values)
x_values <- as.numeric(colnames(wide_form[2:ncol(wide_form)]))
y_values <- as.numeric(wide_form[, 1])
if (verbose) print(x_values)
if (verbose) print(y_values)
wide_form_values <- wide_form_values[order(y_values), order(x_values)]
wide_form_values <- as.numeric(wide_form_values)
x_values <- x_values[order(x_values)]
y_values <- y_values[order(y_values)]
if (verbose) print(x_values)
if (verbose) print(y_values)
if (verbose) print(dim(wide_form_values))
if (verbose) print(length(x_values))
if (verbose) print(length(y_values))
zlim <- range(wide_form_values)
if (verbose) print(zlim)
zlen <- zlim[2] - zlim[1] + 1
if (verbose) print(zlen)
if (colour == "rainbow"){
colourut <- rainbow(zlen, alpha = 0)
if (verbose) print(colourut)
col <- colourut[ wide_form_values - zlim[1] + 1]
# if (verbose) print(col)
} else {
col <- "grey"
if (verbose) print(table(col2))
}
open3d()
plot3d(x_boundaries, y_boundaries, z_boundaries,
box = T, col = "black", xlab = orig_names[1],
ylab = orig_names[2], zlab = orig_names[3])
rgl.surface(z = x_values, ## these are all different because
x = y_values, ## of the confusing way that
y = wide_form_values, ## rgl.surface works! - y is the height!
coords = c(2,3,1),
color = col,
alpha = 1.0,
lit = F,
smooth = smoother)
if (plot_points){
# plot points in red just to be on the safe side!
points3d(fdata, col = "blue")
}
if (plot_contour){
# plot the plane underneath
flat_matrix <- wide_form_values
if (verbose) print(flat_matrix)
y_intercept <- (zlim[2] - zlim[1]) * (-2/3) # put the flat matrix 1/2 the distance below the lower height
flat_matrix[which(flat_matrix != y_intercept)] <- y_intercept
if (verbose) print(flat_matrix)
rgl.surface(z = x_values, ## these are all different because
x = y_values, ## of the confusing way that
y = flat_matrix, ## rgl.surface works! - y is the height!
coords = c(2,3,1),
color = col,
alpha = 1.0,
smooth = smoother)
}
}
The add_rgl_model
does the same job without the options, but overlays a surface onto the existing 3dplot.
add_rgl_model <- function(fdata){
## takes a model in long form, in the format
## 1st column x
## 2nd is y,
## 3rd is z (height)
## and draws an rgl model
##
# note that x has to be ascending, followed by y
print(head(fdata))
fdata <- fdata[order(fdata[, 1], fdata[, 2]), ]
print(head(fdata))
##
require(reshape2)
require(rgl)
orig_names <- colnames(fdata)
#print(head(fdata))
colnames(fdata) <- c("x", "y", "z")
fdata <- as.data.frame(fdata)
## work out the min and max of x,y,z
xlimits <- c(min(fdata$x, na.rm = T), max(fdata$x, na.rm = T))
ylimits <- c(min(fdata$y, na.rm = T), max(fdata$y, na.rm = T))
zlimits <- c(min(fdata$z, na.rm = T), max(fdata$z, na.rm = T))
l <- list (x = xlimits, y = ylimits, z = zlimits)
xyz <- do.call(expand.grid, l)
#print(xyz)
x_boundaries <- xyz$x
#print(class(xyz$x))
y_boundaries <- xyz$y
#print(class(xyz$y))
z_boundaries <- xyz$z
#print(class(xyz$z))
# now turn fdata into a wide format for use with the rgl.surface
fdata[, 2] <- as.character(fdata[, 2])
fdata[, 3] <- as.character(fdata[, 3])
#print(class(fdata[, 2]))
wide_form <- dcast(fdata, y ~ x, value_var = "z")
print(head(wide_form))
wide_form_values <- as.matrix(wide_form[, 2:ncol(wide_form)])
x_values <- as.numeric(colnames(wide_form[2:ncol(wide_form)]))
y_values <- as.numeric(wide_form[, 1])
print(x_values)
print(y_values)
wide_form_values <- wide_form_values[order(y_values), order(x_values)]
x_values <- x_values[order(x_values)]
y_values <- y_values[order(y_values)]
print(x_values)
print(y_values)
print(dim(wide_form_values))
print(length(x_values))
print(length(y_values))
rgl.surface(z = x_values, ## these are all different because
x = y_values, ## of the confusing way that
y = wide_form_values, ## rgl.surface works!
coords = c(2,3,1),
alpha = .8)
# plot points in red just to be on the safe side!
points3d(fdata, col = "red")
}
So my approach would be to, try to do it with all your data (I easily plot surfaces generated from ~15k points). If that doesn't work, take several smaller samples and plot them all at once using these functions.
Differences between unique_ptr and shared_ptr
When wrapping a pointer in a unique_ptr
you cannot have multiple copies of unique_ptr
. The shared_ptr
holds a reference counter which count the number of copies of the stored pointer. Each time a shared_ptr
is copied, this counter is incremented. Each time a shared_ptr
is destructed, this counter is decremented. When this counter reaches 0, then the stored object is destroyed.
Matplotlib: ValueError: x and y must have same first dimension
Changing your lists to numpy
arrays will do the job!!
import matplotlib.pyplot as plt
from scipy import stats
import numpy as np
x = np.array([0.46,0.59,0.68,0.99,0.39,0.31,1.09,0.77,0.72,0.49,0.55,0.62,0.58,0.88,0.78]) # x is a numpy array now
y = np.array([0.315,0.383,0.452,0.650,0.279,0.215,0.727,0.512,0.478,0.335,0.365,0.424,0.390,0.585,0.511]) # y is a numpy array now
xerr = [0.01]*15
yerr = [0.001]*15
plt.rc('font', family='serif', size=13)
m, b = np.polyfit(x, y, 1)
plt.plot(x,y,'s',color='#0066FF')
plt.plot(x, m*x + b, 'r-') #BREAKS ON THIS LINE
plt.errorbar(x,y,xerr=xerr,yerr=0,linestyle="None",color='black')
plt.xlabel('$\Delta t$ $(s)$',fontsize=20)
plt.ylabel('$\Delta p$ $(hPa)$',fontsize=20)
plt.autoscale(enable=True, axis=u'both', tight=False)
plt.grid(False)
plt.xlim(0.2,1.2)
plt.ylim(0,0.8)
plt.show()
How to remove leading zeros from alphanumeric text?
Using regex as some of the answers suggest is a good way to do that. If you don't want to use regex then you can use this code:
String s = "00a0a121";
while(s.length()>0 && s.charAt(0)=='0')
{
s = s.substring(1);
}
Is it possible to use jQuery to read meta tags
$("meta")
Should give you back an array of elements whose tag name is META and then you can iterate over the collection to pick out whatever attributes of the elements you are interested in.
How do I get a class instance of generic type T?
I assume that, since you have a generic class, you would have a variable like that:
private T t;
(this variable needs to take a value at the constructor)
In that case you can simply create the following method:
Class<T> getClassOfInstance()
{
return (Class<T>) t.getClass();
}
Hope it helps!
Start an activity from a fragment
If you are using getActivity() then you have to make sure that the calling activity is added already. If activity has not been added in such case so you may get null when you call getActivity()
in such cases getContext() is safe
then the code for starting the activity will be slightly changed like,
Intent intent = new Intent(getContext(), mFragmentFavorite.class);
startActivity(intent);
Activity, Service and Application extends ContextWrapper class so you can use this or getContext() or getApplicationContext() in the place of first argument.
How to create/make rounded corner buttons in WPF?
You have to create your own ControlTemplate for the Button. just have a look at the sample
created a style called RoundCorner and inside that i changed rather created my own new Control Template with Border (CornerRadius=8) for round corner and some background and other trigger effect. If you have or know Expression Blend it can be done very easily.
<Style x:Key="RoundCorner" TargetType="{x:Type Button}">
<Setter Property="HorizontalContentAlignment" Value="Center"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Padding" Value="1"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Grid x:Name="grid">
<Border x:Name="border" CornerRadius="8" BorderBrush="Black" BorderThickness="2">
<Border.Background>
<RadialGradientBrush GradientOrigin="0.496,1.052">
<RadialGradientBrush.RelativeTransform>
<TransformGroup>
<ScaleTransform CenterX="0.5" CenterY="0.5"
ScaleX="1.5" ScaleY="1.5"/>
<TranslateTransform X="0.02" Y="0.3"/>
</TransformGroup>
</RadialGradientBrush.RelativeTransform>
<GradientStop Offset="1" Color="#00000000"/>
<GradientStop Offset="0.3" Color="#FFFFFFFF"/>
</RadialGradientBrush>
</Border.Background>
<ContentPresenter HorizontalAlignment="Center"
VerticalAlignment="Center"
TextElement.FontWeight="Bold">
</ContentPresenter>
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Background" TargetName="border">
<Setter.Value>
<RadialGradientBrush GradientOrigin="0.496,1.052">
<RadialGradientBrush.RelativeTransform>
<TransformGroup>
<ScaleTransform CenterX="0.5" CenterY="0.5" ScaleX="1.5" ScaleY="1.5"/>
<TranslateTransform X="0.02" Y="0.3"/>
</TransformGroup>
</RadialGradientBrush.RelativeTransform>
<GradientStop Color="#00000000" Offset="1"/>
<GradientStop Color="#FF303030" Offset="0.3"/>
</RadialGradientBrush>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" TargetName="border" Value="#FF33962B"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Opacity" TargetName="grid" Value="0.25"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Using
<Button Style="{DynamicResource RoundCorner}"
Height="25"
VerticalAlignment="Top"
Content="Show"
Width="100"
Margin="5" />
Create a folder if it doesn't already exist
As a complement to current solutions, a utility function.
function createDir($path, $mode = 0777, $recursive = true) {
if(file_exists($path)) return true;
return mkdir($path, $mode, $recursive);
}
createDir('path/to/directory');
It returns true
if already exists or successfully created. Else it returns false.
What is the difference between "::" "." and "->" in c++
In C++ you can access fields or methods, using different operators, depending on it's type:
- ClassName::FieldName : class public static field and methods
- ClassInstance.FieldName : accessing a public field (or method) through class reference
- ClassPointer->FieldName : accessing a public field (or method) dereferencing a class pointer
Note that :: should be used with a class name rather than a class instance, since static fields or methods are common to all instances of a class.
class AClass{
public:
static int static_field;
int instance_field;
static void static_method();
void method();
};
then you access this way:
AClass instance;
AClass *pointer = new AClass();
instance.instance_field; //access instance_field through a reference to AClass
instance.method();
pointer->instance_field; //access instance_field through a pointer to AClass
pointer->method();
AClass::static_field;
AClass::static_method();
using href links inside <option> tag
You cant use href tags within option tags. You will need javascript to do so.
<select name="formal" onchange="javascript:handleSelect(this)">
<option value="home">Home</option>
<option value="contact">Contact</option>
</select>
<script type="text/javascript">
function handleSelect(elm)
{
window.location = elm.value+".php";
}
</script>
React Hooks useState() with Object
If anyone is searching for useState() hooks update for object
- Through Input
const [state, setState] = useState({ fName: "", lName: "" });
const handleChange = e => {
const { name, value } = e.target;
setState(prevState => ({
...prevState,
[name]: value
}));
};
<input
value={state.fName}
type="text"
onChange={handleChange}
name="fName"
/>
<input
value={state.lName}
type="text"
onChange={handleChange}
name="lName"
/>
***************************
- Through onSubmit or button click
setState(prevState => ({
...prevState,
fName: 'your updated value here'
}));
Redirect to a page/URL after alert button is pressed
You're missing semi-colons after your javascript lines. Also, window.location
should have .href
or .replace
etc to redirect - See this post for more information.
echo '<script type="text/javascript">';
echo 'alert("review your answer");';
echo 'window.location.href = "index.php";';
echo '</script>';
For clarity, try leaving PHP tags for this:
?>
<script type="text/javascript">
alert("review your answer");
window.location.href = "index.php";
</script>
<?php
NOTE: semi colons on seperate lines are optional, but encouraged - however as in the comments below, PHP won't break lines in the first example here but will in the second, so semi-colons are required in the first example.
get current url in twig template?
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) %}
The app
global view variable contains all sorts of useful shortcuts, such as app.session
and app.security.token.user
, that reference the services you might use in a controller.
How to get a random value from dictionary?
Here is a little Python code for a dictionary class that can return random keys in O(1) time. (I included MyPy types in this code for readability):
from typing import TypeVar, Generic, Dict, List
import random
K = TypeVar('K')
V = TypeVar('V')
class IndexableDict(Generic[K, V]):
def __init__(self) -> None:
self.keys: List[K] = []
self.vals: List[V] = []
self.dict: Dict[K, int] = {}
def __getitem__(self, key: K) -> V:
return self.vals[self.dict[key]]
def __setitem__(self, key: K, val: V) -> None:
if key in self.dict:
index = self.dict[key]
self.vals[index] = val
else:
self.dict[key] = len(self.keys)
self.keys.append(key)
self.vals.append(val)
def __contains__(self, key: K) -> bool:
return key in self.dict
def __len__(self) -> int:
return len(self.keys)
def random_key(self) -> K:
return self.keys[random.randrange(len(self.keys))]
Replace substring with another substring C++
If you are sure that the required substring is present in the string, then this will replace the first occurence of "abc"
to "hij"
test.replace( test.find("abc"), 3, "hij");
It will crash if you dont have "abc" in test, so use it with care.
Explicitly calling return in a function or not
Question was: Why is not (explicitly) calling return faster or better, and thus preferable?
There is no statement in R documentation making such an assumption.
The main page ?'function' says:
function( arglist ) expr
return(value)
Is it faster without calling return?
Both function()
and return()
are primitive functions and the function()
itself returns last evaluated value even without including return()
function.
Calling return()
as .Primitive('return')
with that last value as an argument will do the same job but needs one call more. So that this (often) unnecessary .Primitive('return')
call can draw additional resources.
Simple measurement however shows that the resulting difference is very small and thus can not be the reason for not using explicit return. The following plot is created from data selected this way:
bench_nor2 <- function(x,repeats) { system.time(rep(
# without explicit return
(function(x) vector(length=x,mode="numeric"))(x)
,repeats)) }
bench_ret2 <- function(x,repeats) { system.time(rep(
# with explicit return
(function(x) return(vector(length=x,mode="numeric")))(x)
,repeats)) }
maxlen <- 1000
reps <- 10000
along <- seq(from=1,to=maxlen,by=5)
ret <- sapply(along,FUN=bench_ret2,repeats=reps)
nor <- sapply(along,FUN=bench_nor2,repeats=reps)
res <- data.frame(N=along,ELAPSED_RET=ret["elapsed",],ELAPSED_NOR=nor["elapsed",])
# res object is then visualized
# R version 2.15
The picture above may slightly difffer on your platform.
Based on measured data, the size of returned object is not causing any difference, the number of repeats (even if scaled up) makes just a very small difference, which in real word with real data and real algorithm could not be counted or make your script run faster.
Is it better without calling return?
Return
is good tool for clearly designing "leaves" of code where the routine should end, jump out of the function and return value.
# here without calling .Primitive('return')
> (function() {10;20;30;40})()
[1] 40
# here with .Primitive('return')
> (function() {10;20;30;40;return(40)})()
[1] 40
# here return terminates flow
> (function() {10;20;return();30;40})()
NULL
> (function() {10;20;return(25);30;40})()
[1] 25
>
It depends on strategy and programming style of the programmer what style he use, he can use no return() as it is not required.
R core programmers uses both approaches ie. with and without explicit return() as it is possible to find in sources of 'base' functions.
Many times only return() is used (no argument) returning NULL in cases to conditially stop the function.
It is not clear if it is better or not as standard user or analyst using R can not see the real difference.
My opinion is that the question should be: Is there any danger in using explicit return coming from R implementation?
Or, maybe better, user writing function code should always ask: What is the effect in not using explicit return (or placing object to be returned as last leaf of code branch) in the function code?
Cannot deserialize the current JSON array (e.g. [1,2,3])
To read more than one json tip (array, attribute) I did the following.
var jVariable = JsonConvert.DeserializeObject<YourCommentaryClass>(jsonVariableContent);
change to
var jVariable = JsonConvert.DeserializeObject <List<YourCommentaryClass>>(jsonVariableContent);
Because you cannot see all the bits in the method used in the foreach
loop.
Example foreach loop
foreach (jsonDonanimSimple Variable in jVariable)
{
debugOutput(jVariable.Id.ToString());
debugOutput(jVariable.Header.ToString());
debugOutput(jVariable.Content.ToString());
}
I also received an error in this loop and changed it as follows.
foreach (jsonDonanimSimple Variable in jVariable)
{
debugOutput(Variable.Id.ToString());
debugOutput(Variable.Header.ToString());
debugOutput(Variable.Content.ToString());
}
How to get input text value on click in ReactJS
First of all, you can't pass to alert
second argument, use concatenation instead
alert("Input is " + inputValue);
Example
However in order to get values from input better to use states like this
_x000D_
_x000D_
var MyComponent = React.createClass({_x000D_
getInitialState: function () {_x000D_
return { input: '' };_x000D_
},_x000D_
_x000D_
handleChange: function(e) {_x000D_
this.setState({ input: e.target.value });_x000D_
},_x000D_
_x000D_
handleClick: function() {_x000D_
console.log(this.state.input);_x000D_
},_x000D_
_x000D_
render: function() {_x000D_
return (_x000D_
<div>_x000D_
<input type="text" onChange={ this.handleChange } />_x000D_
<input_x000D_
type="button"_x000D_
value="Alert the text input"_x000D_
onClick={this.handleClick}_x000D_
/>_x000D_
</div>_x000D_
);_x000D_
}_x000D_
});_x000D_
_x000D_
ReactDOM.render(_x000D_
<MyComponent />,_x000D_
document.getElementById('container')_x000D_
);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="container"></div>
_x000D_
_x000D_
_x000D_
getApplication() vs. getApplicationContext()
It seems to have to do with context wrapping. Most classes derived from Context
are actually a ContextWrapper
, which essentially delegates to another context, possibly with changes by the wrapper.
The context is a general abstraction that supports mocking and proxying. Since many contexts are bound to a limited-lifetime object such as an Activity
, there needs to be a way to get a longer-lived context, for purposes such as registering for future notifications. That is achieved by Context.getApplicationContext()
. A logical implementation is to return the global Application
object, but nothing prevents a context implementation from returning a wrapper or proxy with a suitable lifetime instead.
Activities and services are more specifically associated with an Application
object. The usefulness of this, I believe, is that you can create and register in the manifest a custom class derived from Application
and be certain that Activity.getApplication()
or Service.getApplication()
will return that specific object of that specific type, which you can cast to your derived Application
class and use for whatever custom purpose.
In other words, getApplication()
is guaranteed to return an Application
object, while getApplicationContext()
is free to return a proxy instead.
How to send POST request in JSON using HTTPClient in Android?
In this answer I am using an example posted by Justin Grammens.
About JSON
JSON stands for JavaScript Object Notation. In JavaScript properties can be referenced both like this object1.name
and like this object['name'];
. The example from the article uses this bit of JSON.
The Parts
A fan object with email as a key and [email protected] as a value
{
fan:
{
email : '[email protected]'
}
}
So the object equivalent would be fan.email;
or fan['email'];
. Both would have the same value
of '[email protected]'
.
About HttpClient Request
The following is what our author used to make a HttpClient Request. I do not claim to be an expert at all this so if anyone has a better way to word some of the terminology feel free.
public static HttpResponse makeRequest(String path, Map params) throws Exception
{
//instantiates httpclient to make request
DefaultHttpClient httpclient = new DefaultHttpClient();
//url with the post data
HttpPost httpost = new HttpPost(path);
//convert parameters into JSON object
JSONObject holder = getJsonObjectFromMap(params);
//passes the results to a string builder/entity
StringEntity se = new StringEntity(holder.toString());
//sets the post request as the resulting string
httpost.setEntity(se);
//sets a request header so the page receving the request
//will know what to do with it
httpost.setHeader("Accept", "application/json");
httpost.setHeader("Content-type", "application/json");
//Handles what is returned from the page
ResponseHandler responseHandler = new BasicResponseHandler();
return httpclient.execute(httpost, responseHandler);
}
Map
If you are not familiar with the Map
data structure please take a look at the Java Map reference. In short, a map is similar to a dictionary or a hash.
private static JSONObject getJsonObjectFromMap(Map params) throws JSONException {
//all the passed parameters from the post request
//iterator used to loop through all the parameters
//passed in the post request
Iterator iter = params.entrySet().iterator();
//Stores JSON
JSONObject holder = new JSONObject();
//using the earlier example your first entry would get email
//and the inner while would get the value which would be '[email protected]'
//{ fan: { email : '[email protected]' } }
//While there is another entry
while (iter.hasNext())
{
//gets an entry in the params
Map.Entry pairs = (Map.Entry)iter.next();
//creates a key for Map
String key = (String)pairs.getKey();
//Create a new map
Map m = (Map)pairs.getValue();
//object for storing Json
JSONObject data = new JSONObject();
//gets the value
Iterator iter2 = m.entrySet().iterator();
while (iter2.hasNext())
{
Map.Entry pairs2 = (Map.Entry)iter2.next();
data.put((String)pairs2.getKey(), (String)pairs2.getValue());
}
//puts email and '[email protected]' together in map
holder.put(key, data);
}
return holder;
}
Please feel free to comment on any questions that arise about this post or if I have not made something clear or if I have not touched on something that your still confused about... etc whatever pops in your head really.
(I will take down if Justin Grammens does not approve. But if not then thanks Justin for being cool about it.)
Update
I just happend to get a comment about how to use the code and realized that there was a mistake in the return type.
The method signature was set to return a string but in this case it wasnt returning anything. I changed the signature
to HttpResponse and will refer you to this link on Getting Response Body of HttpResponse
the path variable is the url and I updated to fix a mistake in the code.
ASP.NET Core 1.0 on IIS error 502.5
I got this working with a hard reset of IIS (I had only just installed the hosting package).
Turns out that just pressing 'Restart' in IIS Manager isn't enough. I just had to open a command prompt and type 'iisreset'
What is the equivalent of Java's final in C#?
Java class final and method final -> sealed.
Java member variable final -> readonly for runtime constant, const for compile time constant.
No equivalent for Local Variable final and method argument final
Fullscreen Activity in Android?
For those using AppCompact...
style.xml
<style name="Xlogo" parent="Theme.AppCompat.DayNight.NoActionBar">
<item name="android:windowNoTitle">true</item>
<item name="android:windowFullscreen">true</item>
</style>
Then put the name in your manifest...
How can I determine the status of a job?
This is what I'm using to get the running jobs (principally so I can kill the ones which have probably hung):
SELECT
job.Name, job.job_ID
,job.Originating_Server
,activity.run_requested_Date
,datediff(minute, activity.run_requested_Date, getdate()) AS Elapsed
FROM
msdb.dbo.sysjobs_view job
INNER JOIN msdb.dbo.sysjobactivity activity
ON (job.job_id = activity.job_id)
WHERE
run_Requested_date is not null
AND stop_execution_date is null
AND job.name like 'Your Job Prefix%'
As Tim said, the MSDN / BOL documentation is reasonably good on the contents of the sysjobsX tables. Just remember they are tables in MSDB.
Creating a zero-filled pandas data frame
If you would like the new data frame to have the same index and columns as an existing data frame, you can just multiply the existing data frame by zero:
df_zeros = df * 0
How to save a dictionary to a file?
Unless you really want to keep the dictionary, I think the best solution is to use the csv
Python module to read the file.
Then, you get rows of data and you can change member_phone
or whatever you want ;
finally, you can use the csv
module again to save the file in the same format
as you opened it.
Code for reading:
import csv
with open("my_input_file.txt", "r") as f:
reader = csv.reader(f, delimiter=":")
lines = list(reader)
Code for writing:
with open("my_output_file.txt", "w") as f:
writer = csv.writer(f, delimiter=":")
writer.writerows(lines)
Of course, you need to adapt your change()
function:
def change(lines):
a = input('ID')
for line in lines:
if line[0] == a:
d=str(input("phone"))
line[3]=d
break
else:
print "not"
Bulk Record Update with SQL
You can do this through a regular UPDATE
with a JOIN
UPDATE T1
SET Description = T2.Description
FROM Table1 T1
JOIN Table2 T2
ON T2.ID = T1.DescriptionId
How do I negate a condition in PowerShell?
You almost had it with Not
. It should be:
if (-Not (Test-Path C:\Code)) {
write "it doesn't exist!"
}
You can also use !
: if (!(Test-Path C:\Code)){}
Just for fun, you could also use bitwise exclusive or, though it's not the most readable/understandable method.
if ((test-path C:\code) -bxor 1) {write "it doesn't exist!"}
Unable to convert MySQL date/time value to System.DateTime
I also faced the same problem, and get the columns name and its types. Then cast(col_Name as Char) from table name. From this way i get the problem as '0000-00-00 00:00:00' then I Update as valid date and time the error gets away for my case.
Import data.sql MySQL Docker Container
combine https://stackoverflow.com/a/51837876/1078784
and answers in this question, I think the best answer is:
cat {SQL FILE NAME} | docker exec -i {MYSQL CONTAINER NAME} {MYSQL PATH IN CONTAINER} --init-command="SET autocommit=0;"
for example in my system this command should look like:
cat temp.sql | docker exec -i mysql.master /bin/mysql --init-command="SET autocommit=0;"
also you can use pv to moniter progress:
cat temp.sql | pv | docker exec -i mysql.master /bin/mysql --init-command="SET autocommit=0;"
And the most important thing here is "--init-command" which will speed up the import progress 10 times fast.
$_SERVER['HTTP_REFERER'] missing
SOLUTION
As stated by others very well, HTTP_REFERER is set by the local machine of the user, specifically the browser, which means it's not reliable for security. However, this still is entirely the way in which Google Analytics monitors where you're getting your visitors from, so, it can actually be useful to check, exclude, include, etc..
If you think you should see an HTTP_REFERER and do not, add this to your PHP code, preferably at the top:
ini_set('session.referer_check', 'TRUE');
A more appropriate long-term solution, of course, is to actually update your php.ini or equivalent file. This is a nice and quick way of verifying, though.
TESTING
Run print($_SERVER['HTTP_REFERER']);
on your site, go to google.com, inspect some text, edit it to be <a href="https://example.com">LINK!</a>
, apply the change, then click the link. If it works, all is well and running precisely!
But maybe $_SERVER is wrong, or the test above says it's broken. Update your page with this, and then test again...
<script type="text/javascript">
console.log("REFER!" + document.referrer + "|" + location.referrer + "|");
</script>
USES
I use HTTP REFERER to block spam sites in GoogleAnalytics. Below is a graph focusing on one particular website's referrals. From 0 to 44 in one day, it wasn't caused by real users. It was caused by a botted site trying to get my attention to buy their services. But it just started because php.ini was updated to ignore the referer, which meant these spam, junk garbage sites were not getting their appropriate ERROR 403, "Access Denied."
Android - shadow on text?
Draw 2 texts: one gray (it will be the shadow) and on top of it draw the second text (y coordinate 1px more then shadow text).
Is there a "standard" format for command line/shell help text?
I think there is no standard syntax for command line usage, but most use this convention:
Microsoft Command-Line Syntax, IBM has similar Command-Line Syntax
Text without brackets or braces
Items you must type as shown
<Text inside angle brackets>
Placeholder for which you must supply a value
[Text inside square brackets]
Optional items
{Text inside braces}
Set of required items; choose one
Vertical bar {a|b}
Separator for mutually exclusive items; choose one
Ellipsis <file> …
Items that can be repeated
Maven parent pom vs modules pom
From my experience and Maven best practices there are two kinds of "parent poms"
"company" parent pom - this pom contains your company specific information and configuration that inherit every pom and doesn't need to be copied. These informations are:
- repositories
- distribution managment sections
- common plugins configurations (like maven-compiler-plugin source and target versions)
- organization, developers, etc
Preparing this parent pom need to be done with caution, because all your company poms will inherit from it, so this pom have to be mature and stable (releasing a version of parent pom should not affect to release all your company projects!)
- second kind of parent pom is a multimodule parent. I prefer your first solution - this is a default maven convention for multi module projects, very often represents VCS code structure
The intention is to be scalable to a large scale build so should be scalable to a large number of projects and artifacts.
Mutliprojects have structure of trees - so you aren't arrown down to one level of parent pom. Try to find a suitable project struture for your needs - a classic exmample is how to disrtibute mutimodule projects
distibution/
documentation/
myproject/
myproject-core/
myproject-api/
myproject-app/
pom.xml
pom.xml
A few bonus questions:
- Where is the best place to define the various shared configuration as in source control, deployment directories, common plugins etc. (I'm assuming the parent but I've often been bitten by this and they've ended up in each project rather than a common one).
This configuration has to be wisely splitted into a "company" parent pom and project parent pom(s). Things related to all you project go to "company" parent and this related to current project go to project one's.
- How do the maven-release plugin, hudson and nexus deal with how you set up your multi-projects (possibly a giant question, it's more if anyone has been caught out when by how a multi-project build has been set up)?
Company parent pom have to be released first. For multiprojects standard rules applies. CI server need to know all to build the project correctly.
How to use hex color values
UIColor extension, This will greatly help you! (version:Swift 4.0)
import UIKit
extension UIColor {
/// rgb??
convenience init(r: CGFloat, g: CGFloat, b: CGFloat) {
self.init(red: r/255.0 ,green: g/255.0 ,blue: b/255.0 ,alpha:1.0)
}
/// ??(????)
convenience init(gray: CGFloat) {
self.init(red: gray/255.0 ,green: gray/255.0 ,blue: gray/255.0 ,alpha:1.0)
}
/// ???
class func randomCGColor() -> UIColor {
return UIColor(r: CGFloat(arc4random_uniform(256)), g: CGFloat(arc4random_uniform(256)), b: CGFloat(arc4random_uniform(256)))
}
/// hex??-Int
convenience init(hex:Int, alpha:CGFloat = 1.0) {
self.init(
red: CGFloat((hex & 0xFF0000) >> 16) / 255.0,
green: CGFloat((hex & 0x00FF00) >> 8) / 255.0,
blue: CGFloat((hex & 0x0000FF) >> 0) / 255.0,
alpha: alpha
)
}
/// hex??-String
convenience init(hexString: String){
var red: CGFloat = 0.0
var green: CGFloat = 0.0
var blue: CGFloat = 0.0
var alpha: CGFloat = 1.0
let scanner = Scanner(string: hexString)
var hexValue: CUnsignedLongLong = 0
if scanner.scanHexInt64(&hexValue) {
switch (hexString.characters.count) {
case 3:
red = CGFloat((hexValue & 0xF00) >> 8) / 15.0
green = CGFloat((hexValue & 0x0F0) >> 4) / 15.0
blue = CGFloat(hexValue & 0x00F) / 15.0
case 4:
red = CGFloat((hexValue & 0xF000) >> 12) / 15.0
green = CGFloat((hexValue & 0x0F00) >> 8) / 15.0
blue = CGFloat((hexValue & 0x00F0) >> 4) / 15.0
alpha = CGFloat(hexValue & 0x000F) / 15.0
case 6:
red = CGFloat((hexValue & 0xFF0000) >> 16) / 255.0
green = CGFloat((hexValue & 0x00FF00) >> 8) / 255.0
blue = CGFloat(hexValue & 0x0000FF) / 255.0
case 8:
alpha = CGFloat((hexValue & 0xFF000000) >> 24) / 255.0
red = CGFloat((hexValue & 0x00FF0000) >> 16) / 255.0
green = CGFloat((hexValue & 0x0000FF00) >> 8) / 255.0
blue = CGFloat(hexValue & 0x000000FF) / 255.0
default:
log.info("Invalid RGB string, number of characters after '#' should be either 3, 4, 6 or 8")
}
} else {
log.error("Scan hex error")
}
self.init(red:red, green:green, blue:blue, alpha:alpha)
}}
How to manually update datatables table with new JSON data
Here is solution for legacy datatable 1.9.4
var myData = [
{
"id": 1,
"first_name": "Andy",
"last_name": "Anderson"
}
];
var myData2 = [
{
"id": 2,
"first_name": "Bob",
"last_name": "Benson"
}
];
$('#table').dataTable({
// data: myData,
aoColumns: [
{ mData: 'id' },
{ mData: 'first_name' },
{ mData: 'last_name' }
]
});
$('#table').dataTable().fnClearTable();
$('#table').dataTable().fnAddData(myData2);
Cannot find the object because it does not exist or you do not have permissions. Error in SQL Server
In my case I was running under a different user than the one I was expecting.
I had 'DRIVER={SQL Server};SERVER=...;DATABASE=...;Trusted_Connection=false;User Id=XXX;Password=YYY'
as the connection string I passed to pypyodbc.connect()
, but the connection was still using the credentials of the Windows user that ran the script (I verified this using the SQL Server Profiler and by trying an invalid uid/password combination - which didn't result in an expected error).
I decided not to dig into this further, since switching to this better way of connecting fixed the issue:
conn = pypyodbc.connect(driver='{SQL Server}', server='servername', database='dbname', uid='userName', pwd='Password')
"date(): It is not safe to rely on the system's timezone settings..."
If you don't have access to the file php.ini
, create or edit a .htaccess
file in the root of your domain or sub and add this (generated by cpanel):
<IfModule mime_module>
AddType application/x-httpd-ea-php56 .php .php5 .phtml
</IfModule>
<IfModule php5_module>
php_value date.timezone "America/New_York"
</IfModule>
<IfModule lsapi_module>
php_value date.timezone "America/New_York"
</IfModule>
Best way to pass parameters to jQuery's .load()
As Davide Gualano has been told.
This one
$("#myDiv").load("myScript.php?var=x&var2=y&var3=z")
use GET method for sending the request, and this one
$("#myDiv").load("myScript.php", {var:x, var2:y, var3:z})
use POST method for sending the request. But any limitation that is applied to each method (post/get) is applied to the alternative usages that has been mentioned in the question.
For example: url length limits the amount of sending data in GET method.
How is the default max Java heap size determined?
Finally!
As of Java 8u191 you now have the options:
-XX:InitialRAMPercentage
-XX:MaxRAMPercentage
-XX:MinRAMPercentage
that can be used to size the heap as a percentage of the usable physical RAM. (which is same as the RAM installed less what the kernel uses).
See Release Notes for Java8 u191 for more information. Note that the options are mentioned under a Docker heading but in fact they apply whether you are in Docker environment or in a traditional environment.
The default value for MaxRAMPercentage
is 25%. This is extremely conservative.
My own rule: If your host is more or less dedicated to running the given java application, then you can without problems increase dramatically. If you are on Linux, only running standard daemons and have installed RAM from somewhere around 1 Gb and up then I wouldn't hesitate to use 75% for the JVM's heap. Again, remember that this is 75% of the RAM available, not the RAM installed. What is left is the other user land processes that may be running on the host and the other types of memory that the JVM needs (eg for stack). All together, this will typically fit nicely in the 25% that is left. Obviously, with even more installed RAM the 75% is a safer and safer bet. (I wish the JDK folks had implemented an option where you could specify a ladder)
Setting the MaxRAMPercentage
option look like this:
java -XX:MaxRAMPercentage=75.0 ....
Note that these percentage values are of 'double' type and therefore you must specify them with a decimal dot. You get a somewhat odd error if you use "75" instead of "75.0".
Cannot make a static reference to the non-static method
Since getText()
is non-static you cannot call it from a static method.
To understand why, you have to understand the difference between the two.
Instance (non-static) methods work on objects that are of a particular type (the class). These are created with the new like this:
SomeClass myObject = new SomeClass();
To call an instance method, you call it on the instance (myObject
):
myObject.getText(...)
However a static method/field can be called only on the type directly, say like this:
The previous statement is not correct. One can also refer to static fields with an object reference like myObject.staticMethod()
but this is discouraged because it does not make it clear that they are class variables.
... = SomeClass.final
And the two cannot work together as they operate on different data spaces (instance data and class data)
Let me try and explain. Consider this class (psuedocode):
class Test {
string somedata = "99";
string getText() { return somedata; }
static string TTT = "0";
}
Now I have the following use case:
Test item1 = new Test();
item1.somedata = "200";
Test item2 = new Test();
Test.TTT = "1";
What are the values?
Well
in item1 TTT = 1 and somedata = 200
in item2 TTT = 1 and somedata = 99
In other words, TTT
is a datum that is shared by all the instances of the type. So it make no sense to say
class Test {
string somedata = "99";
string getText() { return somedata; }
static string TTT = getText(); // error there is is no somedata at this point
}
So the question is why is TTT static or why is getText() not static?
Remove the static
and it should get past this error - but without understanding what your type does it's only a sticking plaster till the next error. What are the requirements of getText()
that require it to be non-static?
Internal Error 500 Apache, but nothing in the logs?
If your Internal Server Error information doesn't show up in log files, you probably need to restart the Apache service.
I've found that Apache 2.4 (at least on Windows platform) tends to stubbornly refuse to flush log files—instead, logged data remains in memory for quite a while. It's a good idea from the performance point of view but it can be confusing when developing.
SQL Server String Concatenation with Null
In Sql Server:
insert into Table_Name(PersonName,PersonEmail) values(NULL,'[email protected]')
PersonName is varchar(50), NULL is not a string, because we are not passing with in single codes, so it treat as NULL.
Code Behind:
string name = (txtName.Text=="")? NULL : "'"+ txtName.Text +"'";
string email = txtEmail.Text;
insert into Table_Name(PersonName,PersonEmail) values(name,'"+email+"')
TypeScript, Looping through a dictionary
Ians Answer is good, but you should use const instead of let for the key because it never gets updated.
for (const key in myDictionary) {
let value = myDictionary[key];
// Use `key` and `value`
}
Connect to sqlplus in a shell script and run SQL scripts
This should handle issue:
- WHENEVER SQLERROR EXIT SQL.SQLCODE
- SPOOL ${SPOOL_FILE}
- $RC returns oracle's exit code
- cat from $SPOOL_FILE explains error
SPOOL_FILE=${LOG_DIR}/${LOG_FILE_NAME}.spool
SQLPLUS_OUTPUT=`sqlplus -s "$SFDC_WE_CORE" <<EOF
SET HEAD OFF
SET AUTOPRINT OFF
SET TERMOUT OFF
SET SERVEROUTPUT ON
SPOOL ${SPOOL_FILE}
WHENEVER SQLERROR EXIT SQL.SQLCODE
DECLARE
BEGIN
foooo
--rollback;
END;
/
EOF`
RC=$?
if [[ $RC != 0 ]] ; then
echo " RDBMS exit code : $RC " | tee -a ${LOG_FILE}
cat ${SPOOL_FILE} | tee -a ${LOG_FILE}
cat ${LOG_FILE} | mail -s "Script ${INIT_EXE} failed on $SFDC_ENV" $SUPPORT_LIST
exit 3
fi
Insert HTML with React Variable Statements (JSX)
You don't need any special library or "dangerous" attribute. You can just use React Refs to manipulate the DOM:
class MyComponent extends React.Component {
constructor(props) {
super(props);
this.divRef = React.createRef();
this.myHTML = "<p>Hello World!</p>"
}
componentDidMount() {
this.divRef.current.innerHTML = this.myHTML;
}
render() {
return (
<div ref={this.divRef}></div>
);
}
}
A working sample can be found here:
https://codepen.io/bemipefe/pen/mdEjaMK
How to compare two dates in php
benchmark comparison
date_create, strtotime, DateTime, and direct
direct is faster
$f1="2014-12-12";
$f2="2014-12-13";
$diff=false;
$this->bench('a');
for ($i=0; $i < 20000; $i++) {
$date1=date_create($f1);
$date2=date_create($f2);
$diff=date_diff($date1,$date2);
}
$this->bench('a','b');
for ($i=0; $i < 20000; $i++) {
$date1=strtotime($f1);
$date2=strtotime($f2);
if ($date1>$date2) {
$diff=true;
}
}
$this->bench('b','c');
for ($i=0; $i < 20000; $i++) {
$date1 = new DateTime($f1);
$date2 = new DateTime($f2);
if ($date1>$date2) {
$diff=true;
}
}
$diff=false;
$this->bench('c','d');
for ($i=0; $i < 20000; $i++) {
if ($f1>$f2) {
$diff=true;
}
}
$this->bench('d','e');
var_dump($diff);
$this->dumpr($this->benchs);
results:
[a] => 1610415241.4687
[b] => 1610415242.8759
[a-b] => 1.407194852829
[c] => 1610415243.5672
[b-c] => 0.69137716293335
[d] => 1610415244.7036
[c-d] => 1.1363649368286
[e] => 1610415244.7109
[d-e] => 0.0073208808898926
How to change date format (MM/DD/YY) to (YYYY-MM-DD) in date picker
I used this approach to perform the same operation in my app.
var varDate = $("#dateStart").val();
var DateinISO = $.datepicker.parseDate('mm/dd/yy', varDate);
var DateNewFormat = $.datepicker.formatDate( "yy-mm-dd", new Date( DateinISO ) );
$("#dateStartNewFormat").val(DateNewFormat);
Change multiple files
You could use grep and sed together. This allows you to search subdirectories recursively.
Linux: grep -r -l <old> * | xargs sed -i 's/<old>/<new>/g'
OS X: grep -r -l <old> * | xargs sed -i '' 's/<old>/<new>/g'
For grep:
-r recursively searches subdirectories
-l prints file names that contain matches
For sed:
-i extension (Note: An argument needs to be provided on OS X)
Set maxlength in Html Textarea
<p>
<textarea id="msgc" onkeyup="cnt(event)" rows="1" cols="1"></textarea>
</p>
<p id="valmess2" style="color:red" ></p>
function cnt(event)
{
document.getElementById("valmess2").innerHTML=""; // init and clear if b < max
allowed character
a = document.getElementById("msgc").value;
b = a.length;
if (b > 400)
{
document.getElementById("valmess2").innerHTML="the max length of 400 characters is
reached, you typed in " + b + "characters";
}
}
maxlength is only valid for HTML5. For HTML/XHTML you have to use JavaScript and/or PHP. With PHP you can use strlen for example.This example indicates only the max length, it's NOT blocking the input.
Comparing two branches in Git?
git diff branch_1..branch_2
That will produce the diff between the tips of the two branches. If you'd prefer to find the diff from their common ancestor to test, you can use three dots instead of two:
git diff branch_1...branch_2
Create list or arrays in Windows Batch
@echo off
setlocal
set "list=a b c d"
(
for %%i in (%list%) do (
echo(%%i
echo(
)
)>file.txt
You don't need - actually, can't "declare" variables in batch. Assigning a value to a variable creates it, and assigning an empty string deletes it. Any variable name that doesn't have an assigned value HAS a value of an empty string. ALL variables are strings - WITHOUT exception. There ARE operations that appear to perform (integer) mathematical functions, but they operate by converting back and forth from strings.
Batch is sensitive to spaces in variable names, so your assignment as posted would assign the string "A B C D"
- including the quotes, to the variable "list "
- NOT including the quotes, but including the space. The syntax set "var=string"
is used to assign the value string
to var
whereas set var=string
will do the same thing. Almost. In the first case, any stray trailing spaces after the closing quote are EXCLUDED from the value assigned, in the second, they are INCLUDED. Spaces are a little hard to see when printed.
ECHO
echoes strings. Clasically, it is followed by a space - one of the default separators used by batch (the others are TAB, COMMA, SEMICOLON - any of these do just as well BUT TABS often get transformed to a space-squence by text-editors and the others have grown quirks of their own over the years.) Other characters following the O
in ECHO
have been found to do precisely what the documented SPACE should do. DOT is common. Open-parenthesis (
is probably the most useful since the command
ECHO.%emptyvalue%
will produce a report of the ECHO
state (ECHO is on/off
) whereas
ECHO(%emptyvalue%
will produce an empty line.
The problem with ECHO(
is that the result "looks" unbalanced.
Can I draw rectangle in XML?
Quick and dirty way:
<View
android:id="@+id/colored_bar"
android:layout_width="48dp"
android:layout_height="3dp"
android:background="@color/bar_red" />
Postgres: check if array field contains value?
With ANY operator you can search for only one value.
For example,
select * from mytable where 'Book' = ANY(pub_types);
If you want to search multiple values, you can use @> operator.
For example,
select * from mytable where pub_types @> '{"Journal", "Book"}';
You can specify in which ever order you like.
PHP split alternative?
split
is deprecated since it is part of the family of functions which make use of POSIX regular expressions; that entire family is deprecated in favour of the PCRE (preg_*
) functions.
If you do not need the regular expression functionality, then explode
is a very good choice (and would have been recommended over split
even if that were not deprecated), if on the other hand you do need to use regular expressions then the PCRE alternate is simply preg_split
.
Get User Selected Range
Selection
is its own object within VBA. It functions much like a Range
object.
Selection and Range do not share all the same properties and methods, though, so for ease of use it might make sense just to create a range and set it equal to the Selection, then you can deal with it programmatically like any other range.
Dim myRange as Range
Set myRange = Selection
For further reading, check out the MSDN article.
How can I login to a website with Python?
import cookielib
import urllib
import urllib2
url = 'http://www.someserver.com/auth/login'
values = {'email-email' : '[email protected]',
'password-clear' : 'Combination',
'password-password' : 'mypassword' }
data = urllib.urlencode(values)
cookies = cookielib.CookieJar()
opener = urllib2.build_opener(
urllib2.HTTPRedirectHandler(),
urllib2.HTTPHandler(debuglevel=0),
urllib2.HTTPSHandler(debuglevel=0),
urllib2.HTTPCookieProcessor(cookies))
response = opener.open(url, data)
the_page = response.read()
http_headers = response.info()
# The login cookies should be contained in the cookies variable
For more information visit: https://docs.python.org/2/library/urllib2.html
show more/Less text with just HTML and JavaScript
This is my pure HTML & Javascript solution:
var setHeight = function (element, height) {
if (!element) {;
return false;
}
else {
var elementHeight = parseInt(window.getComputedStyle(element, null).height, 10),
toggleButton = document.createElement('a'),
text = document.createTextNode('...Show more'),
parent = element.parentNode;
toggleButton.src = '#';
toggleButton.className = 'show-more';
toggleButton.style.float = 'right';
toggleButton.style.paddingRight = '15px';
toggleButton.appendChild(text);
parent.insertBefore(toggleButton, element.nextSibling);
element.setAttribute('data-fullheight', elementHeight);
element.style.height = height;
return toggleButton;
}
}
var toggleHeight = function (element, height) {
if (!element) {
return false;
}
else {
var full = element.getAttribute('data-fullheight'),
currentElementHeight = parseInt(element.style.height, 10);
element.style.height = full == currentElementHeight ? height : full + 'px';
}
}
var toggleText = function (element) {
if (!element) {
return false;
}
else {
var text = element.firstChild.nodeValue;
element.firstChild.nodeValue = text == '...Show more' ? '...Show less' : '...Show more';
}
}
var applyToggle = function(elementHeight){
'use strict';
return function(){
toggleHeight(this.previousElementSibling, elementHeight);
toggleText(this);
}
}
var modifyDomElements = function(className, elementHeight){
var elements = document.getElementsByClassName(className);
var toggleButtonsArray = [];
for (var index = 0, arrayLength = elements.length; index < arrayLength; index++) {
var currentElement = elements[index];
var toggleButton = setHeight(currentElement, elementHeight);
toggleButtonsArray.push(toggleButton);
}
for (var index=0, arrayLength=toggleButtonsArray.length; index<arrayLength; index++){
toggleButtonsArray[index].onclick = applyToggle(elementHeight);
}
}
You can then call modifyDomElements function to apply text shortening on all the elements that have shorten-text class name. For that you would need to specify the class name and the height that you would want your elements to be shortened to:
modifyDomElements('shorten-text','50px');
Lastly, in your your html, just set the class name on the element you would want your text to get shorten:
<div class="shorten-text">Your long text goes here...</div>
How to display an image stored as byte array in HTML/JavaScript?
Try putting this HTML snippet into your served document:
<img id="ItemPreview" src="">
Then, on JavaScript side, you can dynamically modify image's src
attribute with so-called Data URL.
document.getElementById("ItemPreview").src = "data:image/png;base64," + yourByteArrayAsBase64;
Alternatively, using jQuery:
$('#ItemPreview').attr('src', `data:image/png;base64,${yourByteArrayAsBase64}`);
This assumes that your image is stored in PNG format, which is quite popular. If you use some other image format (e.g. JPEG), modify the MIME type ("image/..."
part) in the URL accordingly.
Similar Questions:
Set folder browser dialog start location
Set the SelectedPath property before you call ShowDialog ...
folderBrowserDialog1.SelectedPath = @"c:\temp\";
folderBrowserDialog1.ShowDialog();
Will start them at C:\Temp
HTTP Basic Authentication - what's the expected web browser experience?
You can use Postman a plugin for chrome.
It gives the ability to choose the authentication type you need for each of the requests.
In that menu you can configure user and password.
Postman will automatically translate the config to a authentication header that will be sent with your request.
Speed comparison with Project Euler: C vs Python vs Erlang vs Haskell
I made the assumption that the number of factors is only large if the numbers involved have many small factors. So I used thaumkid's excellent algorithm, but first used an approximation to the factor count that is never too small. It's quite simple: Check for prime factors up to 29, then check the remaining number and calculate an upper bound for the nmber of factors. Use this to calculate an upper bound for the number of factors, and if that number is high enough, calculate the exact number of factors.
The code below doesn't need this assumption for correctness, but to be fast. It seems to work; only about one in 100,000 numbers gives an estimate that is high enough to require a full check.
Here's the code:
// Return at least the number of factors of n.
static uint64_t approxfactorcount (uint64_t n)
{
uint64_t count = 1, add;
#define CHECK(d) \
do { \
if (n % d == 0) { \
add = count; \
do { n /= d; count += add; } \
while (n % d == 0); \
} \
} while (0)
CHECK ( 2); CHECK ( 3); CHECK ( 5); CHECK ( 7); CHECK (11); CHECK (13);
CHECK (17); CHECK (19); CHECK (23); CHECK (29);
if (n == 1) return count;
if (n < 1ull * 31 * 31) return count * 2;
if (n < 1ull * 31 * 31 * 37) return count * 4;
if (n < 1ull * 31 * 31 * 37 * 37) return count * 8;
if (n < 1ull * 31 * 31 * 37 * 37 * 41) return count * 16;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43) return count * 32;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47) return count * 64;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47 * 53) return count * 128;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47 * 53 * 59) return count * 256;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47 * 53 * 59 * 61) return count * 512;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47 * 53 * 59 * 61 * 67) return count * 1024;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47 * 53 * 59 * 61 * 67 * 71) return count * 2048;
if (n < 1ull * 31 * 31 * 37 * 37 * 41 * 43 * 47 * 53 * 59 * 61 * 67 * 71 * 73) return count * 4096;
return count * 1000000;
}
// Return the number of factors of n.
static uint64_t factorcount (uint64_t n)
{
uint64_t count = 1, add;
CHECK (2); CHECK (3);
uint64_t d = 5, inc = 2;
for (; d*d <= n; d += inc, inc = (6 - inc))
CHECK (d);
if (n > 1) count *= 2; // n must be a prime number
return count;
}
// Prints triangular numbers with record numbers of factors.
static void printrecordnumbers (uint64_t limit)
{
uint64_t record = 30000;
uint64_t count1, factor1;
uint64_t count2 = 1, factor2 = 1;
for (uint64_t n = 1; n <= limit; ++n)
{
factor1 = factor2;
count1 = count2;
factor2 = n + 1; if (factor2 % 2 == 0) factor2 /= 2;
count2 = approxfactorcount (factor2);
if (count1 * count2 > record)
{
uint64_t factors = factorcount (factor1) * factorcount (factor2);
if (factors > record)
{
printf ("%lluth triangular number = %llu has %llu factors\n", n, factor1 * factor2, factors);
record = factors;
}
}
}
}
This finds the 14,753,024th triangular with 13824 factors in about 0.7 seconds, the 879,207,615th triangular number with 61,440 factors in 34 seconds, the 12,524,486,975th triangular number with 138,240 factors in 10 minutes 5 seconds, and the 26,467,792,064th triangular number with 172,032 factors in 21 minutes 25 seconds (2.4GHz Core2 Duo), so this code takes only 116 processor cycles per number on average. The last triangular number itself is larger than 2^68, so
Quick Sort Vs Merge Sort
It is not true that quicksort is better. ALso, it depends on what you mean better, memory consumption, or speed.
In terms of memory consumption, in worst case, but quicksort can use n^2 memory (i.e. each partition is 1 to n-1), whereas merge sort uses nlogn.
The above follows in terms of speed.
How to write and read a file with a HashMap?
The simplest solution that I can think of is using Properties class.
Saving the map:
Map<String, String> ldapContent = new HashMap<String, String>();
Properties properties = new Properties();
for (Map.Entry<String,String> entry : ldapContent.entrySet()) {
properties.put(entry.getKey(), entry.getValue());
}
properties.store(new FileOutputStream("data.properties"), null);
Loading the map:
Map<String, String> ldapContent = new HashMap<String, String>();
Properties properties = new Properties();
properties.load(new FileInputStream("data.properties"));
for (String key : properties.stringPropertyNames()) {
ldapContent.put(key, properties.get(key).toString());
}
EDIT:
if your map contains plaintext values, they will be visible if you open file data via any text editor, which is not the case if you serialize the map:
ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("data.ser"));
out.writeObject(ldapContent);
out.close();
EDIT2:
instead of for loop (as suggested by OldCurmudgeon) in saving example:
properties.putAll(ldapContent);
however, for the loading example this is the best that can be done:
ldapContent = new HashMap<Object, Object>(properties);
Join/Where with LINQ and Lambda
1 equals 1 two different table join
var query = from post in database.Posts
join meta in database.Post_Metas on 1 equals 1
where post.ID == id
select new { Post = post, Meta = meta };
Accept server's self-signed ssl certificate in Java client
The accepted answer needs an Option 3
ALSO
Option 2 is TERRIBLE. It should NEVER be used (esp. in production) since it provides a FALSE sense of security. Just use HTTP instead of Option 2.
OPTION 3
Use the self-signed certificate to make the Https connection.
Here is an example:
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManagerFactory;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.KeyStore;
/*
* Use a SSLSocket to send a HTTP GET request and read the response from an HTTPS server.
* It assumes that the client is not behind a proxy/firewall
*/
public class SSLSocketClientCert
{
private static final String[] useProtocols = new String[] {"TLSv1.2"};
public static void main(String[] args) throws Exception
{
URL inputUrl = null;
String certFile = null;
if(args.length < 1)
{
System.out.println("Usage: " + SSLSocketClient.class.getName() + " <url>");
System.exit(1);
}
if(args.length == 1)
{
inputUrl = new URL(args[0]);
}
else
{
inputUrl = new URL(args[0]);
certFile = args[1];
}
SSLSocket sslSocket = null;
PrintWriter outWriter = null;
BufferedReader inReader = null;
try
{
SSLSocketFactory sslSocketFactory = getSSLSocketFactory(certFile);
sslSocket = (SSLSocket) sslSocketFactory.createSocket(inputUrl.getHost(), inputUrl.getPort() == -1 ? inputUrl.getDefaultPort() : inputUrl.getPort());
String[] enabledProtocols = sslSocket.getEnabledProtocols();
System.out.println("Enabled Protocols: ");
for(String enabledProtocol : enabledProtocols) System.out.println("\t" + enabledProtocol);
String[] supportedProtocols = sslSocket.getSupportedProtocols();
System.out.println("Supported Protocols: ");
for(String supportedProtocol : supportedProtocols) System.out.println("\t" + supportedProtocol + ", ");
sslSocket.setEnabledProtocols(useProtocols);
/*
* Before any data transmission, the SSL socket needs to do an SSL handshake.
* We manually initiate the handshake so that we can see/catch any SSLExceptions.
* The handshake would automatically be initiated by writing & flushing data but
* then the PrintWriter would catch all IOExceptions (including SSLExceptions),
* set an internal error flag, and then return without rethrowing the exception.
*
* This means any error messages are lost, which causes problems here because
* the only way to tell there was an error is to call PrintWriter.checkError().
*/
sslSocket.startHandshake();
outWriter = sendRequest(sslSocket, inputUrl);
readResponse(sslSocket);
closeAll(sslSocket, outWriter, inReader);
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
closeAll(sslSocket, outWriter, inReader);
}
}
private static PrintWriter sendRequest(SSLSocket sslSocket, URL inputUrl) throws IOException
{
PrintWriter outWriter = new PrintWriter(new BufferedWriter(new OutputStreamWriter(sslSocket.getOutputStream())));
outWriter.println("GET " + inputUrl.getPath() + " HTTP/1.1");
outWriter.println("Host: " + inputUrl.getHost());
outWriter.println("Connection: Close");
outWriter.println();
outWriter.flush();
if(outWriter.checkError()) // Check for any PrintWriter errors
System.out.println("SSLSocketClient: PrintWriter error");
return outWriter;
}
private static void readResponse(SSLSocket sslSocket) throws IOException
{
BufferedReader inReader = new BufferedReader(new InputStreamReader(sslSocket.getInputStream()));
String inputLine;
while((inputLine = inReader.readLine()) != null)
System.out.println(inputLine);
}
// Terminate all streams
private static void closeAll(SSLSocket sslSocket, PrintWriter outWriter, BufferedReader inReader) throws IOException
{
if(sslSocket != null) sslSocket.close();
if(outWriter != null) outWriter.close();
if(inReader != null) inReader.close();
}
// Create an SSLSocketFactory based on the certificate if it is available, otherwise use the JVM default certs
public static SSLSocketFactory getSSLSocketFactory(String certFile)
throws CertificateException, KeyStoreException, IOException, NoSuchAlgorithmException, KeyManagementException
{
if (certFile == null) return (SSLSocketFactory) SSLSocketFactory.getDefault();
Certificate certificate = CertificateFactory.getInstance("X.509").generateCertificate(new FileInputStream(new File(certFile)));
KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
keyStore.load(null, null);
keyStore.setCertificateEntry("server", certificate);
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
trustManagerFactory.init(keyStore);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, trustManagerFactory.getTrustManagers(), null);
return sslContext.getSocketFactory();
}
}
Eclipse : Maven search dependencies doesn't work
For me for this issue worked to:
- remove ~/.m2
- enable "Full Index Enabled" in maven repository view on central repository
- "Rebuild Index" on central maven repository
After eclipse restart everything worked well.
How to sort in-place using the merge sort algorithm?
It really isn't easy or efficient, and I suggest you don't do it unless you really have to (and you probably don't have to unless this is homework since the applications of inplace merging are mostly theoretical). Can't you use quicksort instead? Quicksort will be faster anyway with a few simpler optimizations and its extra memory is O(log N).
Anyway, if you must do it then you must. Here's what I found: one and two. I'm not familiar with the inplace merge sort, but it seems like the basic idea is to use rotations to facilitate merging two arrays without using extra memory.
Note that this is slower even than the classic merge sort that's not inplace.
Converting std::__cxx11::string to std::string
Is it possible that you are using GCC 5?
If you get linker errors about undefined references to symbols that involve types in the std::__cxx11 namespace or the tag [abi:cxx11] then it probably indicates that you are trying to link together object files that were compiled with different values for the _GLIBCXX_USE_CXX11_ABI macro. This commonly happens when linking to a third-party library that was compiled with an older version of GCC. If the third-party library cannot be rebuilt with the new ABI then you will need to recompile your code with the old ABI.
Source: GCC 5 Release Notes/Dual ABI
Defining the following macro before including any standard library headers should fix your problem: #define _GLIBCXX_USE_CXX11_ABI 0
Necessary to add link tag for favicon.ico?
The bottom line is not all browsers will actually look for your favicon.ico file. Some browsers allow users to choose whether or not it should automatically look. Therefore, in order to ensure that it will always appear and get looked at, you do have to define it.
Add event handler for body.onload by javascript within <body> part
body.addEventListener("load", init(), false);
That init() is saying run this function now and assign whatever it returns to the load event.
What you want is to assign the reference to the function, not the result. So you need to drop the ().
body.addEventListener("load", init, false);
Also you should be using window.onload and not body.onload
addEventListener
is supported in most browsers except IE 8.
How to get option text value using AngularJS?
Also you can do like this:
<select class="form-control postType" ng-model="selectedProd">
<option ng-repeat="product in productList" value="{{product}}">{{product.name}}</option>
</select>
where "selectedProd" will be selected product.
Converting file into Base64String and back again
If you want for some reason to convert your file to base-64 string. Like if you want to pass it via internet, etc... you can do this
Byte[] bytes = File.ReadAllBytes("path");
String file = Convert.ToBase64String(bytes);
And correspondingly, read back to file:
Byte[] bytes = Convert.FromBase64String(b64Str);
File.WriteAllBytes(path, bytes);
How to change to an older version of Node.js
run this:
rm -rf node_modules && npm cache clear && npm install
Node will install from whatever is cached. So if you clear everything out first, then NPM use 0.10.xx, it will revert properly.
Which is faster: Stack allocation or Heap allocation
Usually stack allocation just consists of subtracting from the stack pointer register. This is tons faster than searching a heap.
Sometimes stack allocation requires adding a page(s) of virtual memory. Adding a new page of zeroed memory doesn't require reading a page from disk, so usually this is still going to be tons faster than searching a heap (especially if part of the heap was paged out too). In a rare situation, and you could construct such an example, enough space just happens to be available in part of the heap which is already in RAM, but allocating a new page for the stack has to wait for some other page to get written out to disk. In that rare situation, the heap is faster.
How can one pull the (private) data of one's own Android app?
Does that mean that one could chmod the directory from world:--x to world:r-x long enough to be able to fetch the files?
Yes, exactly. Weirdly enough, you also need the file to have the x
bit set. (at least on Android 2.3)
chmod 755
all the way down worked to copy a file (but you should revert permissions afterwards, if you plan to continue using the device).
How to pass multiple checkboxes using jQuery ajax post
Just came across this trying to find a solution for the same problem. Implementing Paul's solution I've made a few tweaks to make this function properly.
var data = { 'venue[]' : []};
$("input:checked").each(function() {
data['venue[]'].push($(this).val());
});
In short the addition of input:checked as opposed to :checked limits the fields input into the array to just the checkboxes on the form. Paul is indeed correct with this
needing to be enclosed as $(this)
Text in Border CSS HTML
You can use a fieldset tag.
_x000D_
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<body>_x000D_
_x000D_
<form>_x000D_
<fieldset>_x000D_
<legend>Personalia:</legend>_x000D_
Name: <input type="text"><br>_x000D_
Email: <input type="text"><br>_x000D_
Date of birth: <input type="text">_x000D_
</fieldset>_x000D_
</form>_x000D_
_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_
Check this link: HTML Tag
Get local href value from anchor (a) tag
This code works for me to get all links of the document
var links=document.getElementsByTagName('a'), hrefs = [];
for (var i = 0; i<links.length; i++)
{
hrefs.push(links[i].href);
}
How to use bitmask?
Let's say I have 32-bit ARGB value with 8-bits per channel. I want to replace the alpha component with another alpha value, such as 0x45
unsigned long alpha = 0x45
unsigned long pixel = 0x12345678;
pixel = ((pixel & 0x00FFFFFF) | (alpha << 24));
The mask turns the top 8 bits to 0, where the old alpha value was. The alpha value is shifted up to the final bit positions it will take, then it is OR-ed into the masked pixel value. The final result is 0x45345678 which is stored into pixel.
ADB No Devices Found
There could be two reasons why adb devices
command is not working for you. Either your phones USB drivers are not installed properly or you have not enabled USB debugging mode.
I created a tool that makes installing USB drivers a one click thing.
Just connect your phone in USB debugging mode to PC.
Run my tool
It will detect and install drivers specific to your phone and also install the latest ADB & Fastboot binaries with it.
The tool is available at my GitHub Repo
How can a Javascript object refer to values in itself?
This is not JSON. JSON was designed to be simple; allowing arbitrary expressions is not simple.
In full JavaScript, I don't think you can do this directly. You cannot refer to this
until the object called obj
is fully constructed. So you need a workaround, that someone with more JavaScript-fu than I will provide.
Where does Hive store files in HDFS?
Hive tables may not necessarily be stored in a warehouse (since you can create tables located anywhere on the HDFS).
You should use DESCRIBE FORMATTED <table_name>
command.
hive -S -e "describe formatted <table_name> ;" | grep 'Location' | awk '{ print $NF }'
Please note that partitions may be stored in different places and to get the location of the alpha=foo/beta=bar
partition you'd have to add partition(alpha='foo',beta='bar')
after <table_name>
.
Routing with multiple Get methods in ASP.NET Web API
using Routing.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
namespace Routing.Controllers
{
public class StudentsController : ApiController
{
static List<Students> Lststudents =
new List<Students>() { new Students { id=1, name="kim" },
new Students { id=2, name="aman" },
new Students { id=3, name="shikha" },
new Students { id=4, name="ria" } };
[HttpGet]
public IEnumerable<Students> getlist()
{
return Lststudents;
}
[HttpGet]
public Students getcurrentstudent(int id)
{
return Lststudents.FirstOrDefault(e => e.id == id);
}
[HttpGet]
[Route("api/Students/{id}/course")]
public IEnumerable<string> getcurrentCourse(int id)
{
if (id == 1)
return new List<string>() { "emgili", "hindi", "pun" };
if (id == 2)
return new List<string>() { "math" };
if (id == 3)
return new List<string>() { "c#", "webapi" };
else return new List<string>() { };
}
[HttpGet]
[Route("api/students/{id}/{name}")]
public IEnumerable<Students> getlist(int id, string name)
{ return Lststudents.Where(e => e.id == id && e.name == name).ToList(); }
[HttpGet]
public IEnumerable<string> getlistcourse(int id, string name)
{
if (id == 1 && name == "kim")
return new List<string>() { "emgili", "hindi", "pun" };
if (id == 2 && name == "aman")
return new List<string>() { "math" };
else return new List<string>() { "no data" };
}
}
}
Entity Framework - Generating Classes
1) First you need to generate EDMX
model using your database. To do that you should add new item to your project:
- Select
ADO.NET Entity Data Model
from the Templates list.
- On the Choose Model Contents page, select the Generate from Database option and click Next.
- Choose your database.
- On the Choose Your Database Objects page, check the Tables. Choose Views or Stored Procedures if you need.
So now you have Model1.edmx
file in your project.
2) To generate classes using your model:
- Open your
EDMX
model designer.
- On the design surface Right Click –> Add Code Generation Item…
- Select Online templates.
- Select
EF 4.x DbContext Generator for C#
.
- Click ‘Add’.
Notice that two items are added to your project:
Model1.tt
(This template generates very simple POCO classes for each entity in your model)
Model1.Context.tt
(This template generates a derived DbContext to use for querying and persisting data)
3) Read/Write Data example:
var dbContext = new YourModelClass(); //class derived from DbContext
var contacts = from c in dbContext.Contacts select c; //read data
contacts.FirstOrDefault().FirstName = "Alex"; //edit data
dbContext.SaveChanges(); //save data to DB
Don't forget that you need 4.x version of EntityFramework. You can download EF 4.1 here: Entity Framework 4.1.
How can I perform static code analysis in PHP?
Run php
in lint mode from the command line to validate syntax without execution:
php -l FILENAME
Higher-level static analyzers include:
Lower-level analyzers include:
Runtime analyzers, which are more useful for some things due to PHP's dynamic nature, include:
The documentation libraries phpdoc and Doxygen perform a kind of code analysis. Doxygen, for example, can be configured to render nice inheritance graphs with Graphviz.
Another option is xhprof, which is similar to Xdebug, but lighter, making it suitable for production servers. The tool includes a PHP-based interface.
How to encode text to base64 in python
To compatibility with both py2 and py3
import six
import base64
def b64encode(source):
if six.PY3:
source = source.encode('utf-8')
content = base64.b64encode(source).decode('utf-8')
How do I pass a string into subprocess.Popen (using the stdin argument)?
"""
Ex: Dialog (2-way) with a Popen()
"""
p = subprocess.Popen('Your Command Here',
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
stdin=PIPE,
shell=True,
bufsize=0)
p.stdin.write('START\n')
out = p.stdout.readline()
while out:
line = out
line = line.rstrip("\n")
if "WHATEVER1" in line:
pr = 1
p.stdin.write('DO 1\n')
out = p.stdout.readline()
continue
if "WHATEVER2" in line:
pr = 2
p.stdin.write('DO 2\n')
out = p.stdout.readline()
continue
"""
..........
"""
out = p.stdout.readline()
p.wait()
How to use GNU Make on Windows?
user1594322 gave a correct answer but when I tried it I ran into admin/permission problems. I was able to copy 'mingw32-make.exe' and paste it, over-ruling/by-passing admin issues and then editing the copy to 'make.exe'. On VirtualBox in a Win7 guest.
Check if enum exists in Java
I don't know why anyone told you that catching runtime exceptions was bad.
Use valueOf
and catching IllegalArgumentException
is fine for converting/checking a string to an enum.
.attr("disabled", "disabled") issue
Thank you all for your contribution! I found the problem:
ITS A FIREBUG BUG !!!
My code works. I have asked the PHP Dev to change the input types hidden in to input type text.
The disabled feature works. But the firebug console does not update this status!
you can test out this firebug bug by your self here http://jsbin.com/uneti3/3#. Thx to aSeptik for the example page.
update: 2. June 2012: Firebug in FF11 still has this bug.
Read specific columns from a csv file with csv module?
Context: For this type of work you should use the amazing python petl library. That will save you a lot of work and potential frustration from doing things 'manually' with the standard csv module. AFAIK, the only people who still use the csv module are those who have not yet discovered better tools for working with tabular data (pandas, petl, etc.), which is fine, but if you plan to work with a lot of data in your career from various strange sources, learning something like petl is one of the best investments you can make. To get started should only take 30 minutes after you've done pip install petl. The documentation is excellent.
Answer: Let's say you have the first table in a csv file (you can also load directly from the database using petl). Then you would simply load it and do the following.
from petl import fromcsv, look, cut, tocsv
#Load the table
table1 = fromcsv('table1.csv')
# Alter the colums
table2 = cut(table1, 'Song_Name','Artist_ID')
#have a quick look to make sure things are ok. Prints a nicely formatted table to your console
print look(table2)
# Save to new file
tocsv(table2, 'new.csv')
Failed to create provisioning profile
Check these things.
1.A device is connected to your system or not.
2.Deployment target in xcode. (General->Deployment info->Deployment target)
It should match with the ios version of your device.
3.Change your bundle identifier. Follow general rules of setting a unique bundle identifier for yourproject while running in device.
See this what is correct format of bundle identifier in iOS?
Also be careful with the number of bundle identifiers you set in the project. Please remember all bundle identifiers or note it down somewhere. Since you are using a free account you have limited access to the number of bundle id's.
You should also disable push notifications in the "Capabilities" section of the project. Try changing "App groups" as well in the format of group.com.someString.
These things helped me run my app in real device without any errors.
How to make an embedded video not autoplay
I had the same problem and came across this post. Nothing worked. After randomly playing around, I found that <embed ........ play="false">
stopped it from playing automatically. I now have the problem that I can't get a controller to appear, so can't start the movie! :S
MySQL LIMIT on DELETE statement
DELETE t.* FROM test t WHERE t.name = 'foo' LIMIT 1
@Andre If I understood what you are asking, I think the only thing missing is the t.* before FROM
.
HTTP Range header
As Wrikken suggested, it's a valid request. It's also quite common when the client is requesting media or resuming a download.
A client will often test to see if the server handles ranged requests other than just looking for an Accept-Ranges
response. Chrome always sends a Range: bytes=0-
with its first GET request for a video, so it's something you can't dismiss.
Whenever a client includes Range:
in its request, even if it's malformed, it's expecting a partial content (206) response. When you seek forward during HTML5 video playback, the browser only requests the starting point. For example:
Range: bytes=3744-
So, in order for the client to play video properly, your server must be able to handle these incomplete range requests.
You can handle the type of 'range' you specified in your question in two ways:
First, You could reply with the requested starting point given in the response, then the total length of the file minus one (the requested byte range is zero-indexed). For example:
Request:
GET /BigBuckBunny_320x180.mp4
Range: bytes=100-
Response:
206 Partial Content
Content-Type: video/mp4
Content-Length: 64656927
Accept-Ranges: bytes
Content-Range: bytes 100-64656926/64656927
Second, you could reply with the starting point given in the request and an open-ended file length (size). This is for webcasts or other media where the total length is unknown. For example:
Request:
GET /BigBuckBunny_320x180.mp4
Range: bytes=100-
Response:
206 Partial Content
Content-Type: video/mp4
Content-Length: 64656927
Accept-Ranges: bytes
Content-Range: bytes 100-64656926/*
Tips:
You must always respond with the content length included with the range. If the range is complete, with start to end, then the content length is simply the difference:
Request:
Range: bytes=500-1000
Response:
Content-Range: bytes 500-1000/123456
Remember that the range is zero-indexed, so Range: bytes=0-999
is actually requesting 1000 bytes, not 999, so respond with something like:
Content-Length: 1000
Content-Range: bytes 0-999/123456
Or:
Content-Length: 1000
Content-Range: bytes 0-999/*
But, avoid the latter method if possible because some media players try to figure out the duration from the file size. If your request is for media content, which is my hunch, then you should include its duration in the response. This is done with the following format:
X-Content-Duration: 63.23
This must be a floating point. Unlike Content-Length
, this value doesn't have to be accurate. It's used to help the player seek around the video. If you are streaming a webcast and only have a general idea of how long it will be, it's better to include your estimated duration rather than ignore it altogether. So, for a two-hour webcast, you could include something like:
X-Content-Duration: 7200.00
With some media types, such as webm, you must also include the content-type, such as:
Content-Type: video/webm
All of these are necessary for the media to play properly, especially in HTML5. If you don't give a duration, the player may try to figure out the duration (to allow for seeking) from its file size, but this won't be accurate. This is fine, and necessary for webcasts or live streaming, but not ideal for playback of video files. You can extract the duration using software like FFMPEG and save it in a database or even the filename.
X-Content-Duration
is being phased out in favor of Content-Duration
, so I'd include that too. A basic, response to a "0-" request would include at least the following:
HTTP/1.1 206 Partial Content
Date: Sun, 08 May 2013 06:37:54 GMT
Server: Apache/2.0.52 (Red Hat)
Accept-Ranges: bytes
Content-Length: 3980
Content-Range: bytes 0-3979/3980
Content-Type: video/webm
X-Content-Duration: 2054.53
Content-Duration: 2054.53
One more point: Chrome always starts its first video request with the following:
Range: bytes=0-
Some servers will send a regular 200 response as a reply, which it accepts (but with limited playback options), but try to send a 206 instead to show than your server handles ranges. RFC 2616 says it's acceptable to ignore range headers.
How to call a method after a delay in Android
I created simpler method to call this.
public static void CallWithDelay(long miliseconds, final Activity activity, final String methodName)
{
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
try {
Method method = activity.getClass().getMethod(methodName);
method.invoke(activity);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}, miliseconds);
}
To use it, just call : .CallWithDelay(5000, this, "DoSomething");
C# : Passing a Generic Object
It doesn't compile because T could be anything, and not everything will have the myvar
field.
You could make myvar
a property on ITest
:
public ITest
{
string myvar{get;}
}
and implement it on the classes as a property:
public class MyClass1 : ITest
{
public string myvar{ get { return "hello 1"; } }
}
and then put a generic constraint on your method:
public void PrintGeneric<T>(T test) where T : ITest
{
Console.WriteLine("Generic : " + test.myvar);
}
but in that case to be honest you are better off just passing in an ITest:
public void PrintGeneric(ITest test)
{
Console.WriteLine("Generic : " + test.myvar);
}
Comparing two arrays & get the values which are not common
Look at Compare-Object
Compare-Object $a1 $b1 | ForEach-Object { $_.InputObject }
Or if you would like to know where the object belongs to, then look at SideIndicator:
$a1=@(1,2,3,4,5,8)
$b1=@(1,2,3,4,5,6)
Compare-Object $a1 $b1
How to get a shell environment variable in a makefile?
If you've exported the environment variable:
export demoPath=/usr/local/demo
you can simply refer to it by name in the makefile
(make
imports all the environment variables you have set):
DEMOPATH = ${demoPath} # Or $(demoPath) if you prefer.
If you've not exported the environment variable, it is not accessible until you do export it, or unless you pass it explicitly on the command line:
make DEMOPATH="${demoPath}" …
If you are using a C shell derivative, substitute setenv demoPath /usr/local/demo
for the export
command.
Why do we assign a parent reference to the child object in Java?
Let's say you'd like to have an array of instances of Parent class, and a set of child classes Child1, Child2, Child3 extending Parent. There're situations when you're only interested with the parent class implementation, which is more general, and do not care about more specific stuff introduced by child classes.
Height equal to dynamic width (CSS fluid layout)
[Update: Although I discovered this trick independently, I’ve since learned that Thierry Koblentz beat me to it. You can find his 2009 article on A List Apart. Credit where credit is due.]
I know this is an old question, but I encountered a similar problem that I did solve only with CSS. Here is my blog post that discusses the solution. Included in the post is a live example. Code is reposted below.
_x000D_
_x000D_
#container {
display: inline-block;
position: relative;
width: 50%;
}
#dummy {
margin-top: 75%;
/* 4:3 aspect ratio */
}
#element {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
background-color: silver/* show me! */
}
_x000D_
<div id="container">
<div id="dummy"></div>
<div id="element">
some text
</div>
</div>
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How to add a single item to a Pandas Series
Here is another thought n for appending multiple items in one line without changing the name of series. However, this may be not as efficient as the other answer.
>>> df = pd.Series(np.random.random(5), name='random')
>>> df
0 0.363885
1 0.402623
2 0.450449
3 0.172917
4 0.983481
Name: random, dtype: float64
>>> df.to_frame().T.assign(a=3, b=2, c=5).squeeze()
0 0.363885
1 0.402623
2 0.450449
3 0.172917
4 0.983481
a 3.000000
b 2.000000
c 5.000000
Name: random, dtype: float64
Get an object's class name at runtime
In Angular2, this can help to get components name:
getName() {
let comp:any = this.constructor;
return comp.name;
}
comp:any is needed because TypeScript compiler will issue errors since Function initially does not have property name.
Correct way to write loops for promise.
Using the standard promise object, and having the promise return the results.
function promiseMap (data, f) {
const reducer = (promise, x) =>
promise.then(acc => f(x).then(y => acc.push(y) && acc))
return data.reduce(reducer, Promise.resolve([]))
}
var emails = []
function getUser(email) {
return db.getUser(email)
}
promiseMap(emails, getUser).then(emails => {
console.log(emails)
})
How to compare each item in a list with the rest, only once?
This code will count frequency and remove duplicate elements:
from collections import Counter
str1='the cat sat on the hat hat'
int_list=str1.split();
unique_list = []
for el in int_list:
if el not in unique_list:
unique_list.append(el)
else:
print "Element already in the list"
print unique_list
c=Counter(int_list)
c.values()
c.keys()
print c
Git pull till a particular commit
I've found the updated answer from this video, the accepted answer didn't work for me.
First clone the latest repo from git (if haven't) using
git clone <HTTPs link of the project>
(or using SSH) then go to the desire branch using
git checkout <branch name>
.
Use the command
git log
to check the latest commits.
Copy the shal of the particular commit. Then use the command
git fetch origin <Copy paste the shal here>
After pressing enter key. Now use the command
git checkout FETCH_HEAD
Now the particular commit will be available to your local. Change anything and push the code using git push origin <branch name>
. That's all.
Check the video for reference.
c++ bool question
false == 0
and true = !false
i.e. anything that is not zero and can be converted to a boolean is not false
, thus it must be true
.
Some examples to clarify:
if(0) // false
if(1) // true
if(2) // true
if(0 == false) // true
if(0 == true) // false
if(1 == false) // false
if(1 == true) // true
if(2 == false) // false
if(2 == true) // false
cout << false // 0
cout << true // 1
true
evaluates to 1
, but any int
that is not false
(i.e. 0
) evaluates to true
but is not equal to true
since it isn't equal to 1
.
VBA Excel sort range by specific column
Try this code:
Dim lastrow As Long
lastrow = Cells(Rows.Count, 2).End(xlUp).Row
Range("A3:D" & lastrow).Sort key1:=Range("B3:B" & lastrow), _
order1:=xlAscending, Header:=xlNo
Where should I put <script> tags in HTML markup?
Just before the closing body tag, as stated on
http://developer.yahoo.com/performance/rules.html#js_bottom
Put Scripts at the Bottom
The problem caused by scripts is that they block parallel downloads. The HTTP/1.1 specification suggests that browsers download no more than two components in parallel per hostname. If you serve your images from multiple hostnames, you can get more than two downloads to occur in parallel. While a script is downloading, however, the browser won't start any other downloads, even on different hostnames.
How to set JAVA_HOME in Linux for all users
1...Using the short cut Ctlr
+ Alt
+ T
to open terminal
2...Execute the below command:
echo export JAVA_HOME='$(readlink -f /usr/bin/javac | sed "s:/bin/javac::")' | sudo tee /etc/profile.d/jdk_home.sh > /dev/null
3...(Recommended) Restart your VM / computer. You can use source /etc/source
if don't want to restart computer
4...Using the short cut Ctlr
+ Alt
+ T
to open terminal
5...Verified JAVA_HOME installment with
echo $JAVA_HOME
One-liner copy from flob, credit to them
How to validate inputs dynamically created using ng-repeat, ng-show (angular)
Added more complex example with "custom validation" on the side of controller http://jsfiddle.net/82PX4/3/
<div class='line' ng-repeat='line in ranges' ng-form='lineForm'>
low: <input type='text'
name='low'
ng-pattern='/^\d+$/'
ng-change="lowChanged(this, $index)" ng-model='line.low' />
up: <input type='text'
name='up'
ng-pattern='/^\d+$/'
ng-change="upChanged(this, $index)"
ng-model='line.up' />
<a href ng-if='!$first' ng-click='removeRange($index)'>Delete</a>
<div class='error' ng-show='lineForm.$error.pattern'>
Must be a number.
</div>
<div class='error' ng-show='lineForm.$error.range'>
Low must be less the Up.
</div>
</div>
Integer expression expected error in shell script
This error can also happen if the variable you are comparing has hidden characters that are not numbers/digits.
For example, if you are retrieving an integer from a third-party script, you must ensure that the returned string does not contain hidden characters, like "\n"
or "\r"
.
For example:
#!/bin/bash
# Simulate an invalid number string returned
# from a script, which is "1234\n"
a='1234
'
if [ "$a" -gt 1233 ] ; then
echo "number is bigger"
else
echo "number is smaller"
fi
This will result in a script error : integer expression expected
because $a
contains a non-digit newline character "\n"
. You have to remove this character using the instructions here: How to remove carriage return from a string in Bash
So use something like this:
#!/bin/bash
# Simulate an invalid number string returned
# from a script, which is "1234\n"
a='1234
'
# Remove all new line, carriage return, tab characters
# from the string, to allow integer comparison
a="${a//[$'\t\r\n ']}"
if [ "$a" -gt 1233 ] ; then
echo "number is bigger"
else
echo "number is smaller"
fi
You can also use set -xv
to debug your bash script and reveal these hidden characters. See https://www.linuxquestions.org/questions/linux-newbie-8/bash-script-error-integer-expression-expected-934465/