I have found that my arduino app will crash if I use the following logic:
if (boolA && boolB) {
doSomething();
}
In a simple program it will work, but with a sufficiently large project, I find I have to change the above to:
if (boolA) {
if (boolB) {
doSomething();
}
}
In a number of projects I have tracked the cause to this logic.
If you want to check memory, you can do so by using Available Memory.
And here I put those files into a library you can use more easily: Avalaible Memory Lib
Although, actual code would be better to try to solve your problem...
You many need to use the long hand syntax like,
if (boolA==HIGH && boolB ==HIGH) {
doSomething();
}
This may also help:
http://forum.arduino.cc/index.php/topic,43588.0.html
Related
Let's say I have these classes:
Old_Class
New_Class
If this exists ->something(new Old_Class()) or Old_Class::staticMethod() or $oldClass->methodCall() I want a code sniff to warn "Old_Class usage found, recommend using New_Class instead".
I found this sniff Generic.PHP.ForbiddenFunctions but it only seems to catch built-in php functions is_array, is_null, etc.
Do I need to write a custom sniff for this?
If so, what token should I added to the register() function to catch on?
I couldn't use a built-in one. I had to write one using T_STRING.
public function register()
{
return [
T_STRING,
];
}
public function process(PHP_CodeSniffer_File $phpcsFile, $stackPtr)
{
$tokens = $phpcsFile->getTokens();
if ($tokens[$stackPtr]['content'] === 'Old_Class') {
$error = 'Old_Class usage found, consider using New_Class instead.';
$phpcsFile->addWarning($error, $stackPtr);
}
}
I know this is a fairly old question, but there are two possible solutions I'm aware of:
The Slevomat coding standard for Codesniffer includes a sniff to report usage of any of an array of forbidden classes
Static analysis tools are another approach for this. If you mark a class with the #deprecated annotation, I know from personal experience that Psalm will flag it with the DeprecatedClass issue, and if you can't fix them all at once, you can add them to the baseline, which will suppress the issue, but keep track of it, so you can still use Psalm in continuous integration and not break on existing issues. I believe PHPStan has similar functionality.
In unity multiplayer the player prefab spawns after the scene loads, what is the best way to declare scripts that are needed and avoid the NullReferenceException error?
I'm not that familiar with multiplayer myself, but I believe this could be done through GameObject.Find("") and GetComponent.
I also stumbled across FindObjectOfType. I'm not sure if that's what you're looking for, but it doesn't hurt to post it. Good luck.
Instead of letting a script look for when the prefabs have spawned why not letting the prefabs tell the script it has spawned?
It's really hard to give any kind of example when the use-case is not specified.
Really basic example (and since you're going to use it for networking you might have to redo this a lot so you don't trust the client too much):
class ScriptA : Monobehaviour () {
List<GameObject> prefabs;
public void AddPrefab (GameObject Prefab) {
prefabs.Add (Prefab)
}
}
class Prefab : Monobehaviour () {
void Start () {
FindObjectOfType(ScriptA).AddPrefab(gameObject);
}
}
It's not the best example but the point is, you might need to rethink the architecture
I know, that to create a new path in Qt from a given absolute path, you use QDir::makepath() as dir.makepath(path), as it is suggested in this question. I do not have any trouble in using it and it works fine. My question is directed, as to why the developers would not provide a static function to call in a way like QDir::makepath("/Users/me/somepath/");. Needing to create a new QDir instance seems unnecessary to me.
I can only think of two possible reasons:
1. The developers were "lazy" or did not have time so they did not add one as it is not absolutely necessary.
2. The instance of QDir on which mkpath(path) is called, will be set to path as well, so it would be convenient for further usage - but I can not seem to find any hints that this is the actual behaviour within the docs.
I know I repeat myself, but again, I do not need help as of how to do it, but I am much interested as of why one has to do it that way.
Thanks for any reason I might have missed.
Let's have a look at the code of said method:
bool QDir::mkdir(const QString &dirName) const
{
const QDirPrivate* d = d_ptr.constData();
if (dirName.isEmpty()) {
qWarning("QDir::mkdir: Empty or null file name");
return false;
}
QString fn = filePath(dirName);
if (d->fileEngine.isNull())
return QFileSystemEngine::createDirectory(QFileSystemEntry(fn), false);
return d->fileEngine->mkdir(fn, false);
}
Source: http://code.qt.io/cgit/qt/qtbase.git/tree/src/corelib/io/qdir.cpp#n1381
As we can see, a static version would be simple to implement:
bool QDir::mkdir(const QString &dirName) const
{
if (dirName.isEmpty()) {
qWarning("QDir::mkdir: Empty or null file name");
return false;
}
return QFileSystemEngine::createDirectory(QFileSystemEntry(dirName), false);
}
(see also http://code.qt.io/cgit/qt/qtbase.git/tree/src/corelib/io/qdir.cpp#n681)
First, the non-static method comes with a few advantages. Obviously there is something to using the object's existing file engine. But also, I would imagine the use-case of creating several directories under a specific directory (that the QDir already points to).
So why not provide both?
Verdict (tl/dr): I think the reason is simple code hygiene. When you use the API, the difference between QDir::makepath(path); and QDir().makepath(path); is slim. The performance hit of creating the object is also negligible, as you would reuse the same object if you happen to perform the operation more often. But on the side of the code maintainers, it is arguably much more convenient (less work and less error prone) to not maintain two versions of the same method.
[Edit]
The main question here loosely translates as 'is Flex multi-threaded'? I have since found out that it is not, so I won't have data mysteriously changing half way through an operation. The code below worked, but made things awkward and confusing. I eventually fixed the problem with an architecture change, eliminating the need to suppress events. As the first commenter suggested.
Infinite loops were eliminated by changing the way events were listened to and performing certain actions explicitly rather than via events.
Collating events was made easier using a command pattern.
Basically, do not use the code below if you come across this page!
[/Edit]
I'm building some Flex applications using a simple, lightweight MVC pattern. Models extend or encapsulate a dispatcher and fire events when updated. I'm stuck with Flex 3.5.
In some situations, I'll want to suppress these events to avoid infinite loops or help collate multiple actions into a single event.
My first stab at a solution that doesn't litter the models with unnecessary and confusing code is this:
private var _suppressEvents:Boolean = false;
public function suppressEvents(callback:Function):void
{
// In case of error, ensure the suppression is turned off, then re-throw
var err:Error = null;
_suppressEvents = true;
try
{
callback();
}
catch(e:Error)
{
err = e;
}
_suppressEvents = false;
if (err)
{
throw (err);
}
}
public function dispatch(type:String, data:*):void
{
// Suppress if called from a suppress callback.
if (!_suppressEvents)
{
_dispatcher.dispatchEvent(new DataEvent(type, data));
}
}
Obviously I call 'suppressEvents' with a function containing the model code I wish to run.
My questions:
1: Is there a chance I could accidentally lose events using this technique?
2: Do I need to think about any other error edge cases when it comes to ensuring I don't accidentally end up in a suppressed state after a call?
3: Is there a cleaner way I'm missing?
Thanks!
I need to create a job with a for loop (I think) that goes through all available companies and checks for a specific value. I'm just not familiar with how I would get it to select each individual company.
Does anyone know the syntax for that?
I use the following technique in a job:
static void CountIt(Args _args)
{
DataArea DataArea;
void doIt()
{;
info(int2str((select Count(RecId) from CustTable).RecId));
}
setPrefix("Counting");
while select DataArea where !DataArea.isVirtual
{
print(DataArea.Id);
setPrefix(DataArea.Id);
changecompany (DataArea.Id)
{
doIt();
}
}
}
Please bear in mind to reset your table variables in the changecompany scope, otherwise you will get strange or no result at all.
A colleague was to do a task as yours and he got absolutely no results for the code inside the changecompany scope. I googled and found this blogpost: http://dynamics-ax-live.blogspot.se/2011/10/what-not-to-forget-when-using.html
The functionality you're looking for is called "Cross Company" data access. MSDN has a great bit of code samples here:
X++ code:
http://msdn.microsoft.com/en-us/library/cc518738.aspx
Main article:
http://msdn.microsoft.com/en-us/library/cc634544.aspx