The Linux Page

object

Convert XML tags and text to a String

Today I started testing a lot of my JavaScript / jQuery code from a website I am building for a customer. I got an error, at some point, saying:

SCRIPT5007: Unable to get property 'replace' of undefined or null reference

The error was in link with the 'replace' function being referenced on an innerHTML of an element. More specifically, one of those XML element (probably the top most one.)

The fact is that Internet Explorer does not support innerHTML in an XML document. Not to be too surprised about that, XML is not HTML so there is really no reason why innerHTML should be ...

Classes in JavaScript (from complex objects to proper classes)

When creating objects (commonly called JavaScript classes) in your JavaScript code, you want to use the prototype. This is the only clean way of doing it. In JavaScript, you can create objects on the fly, but those are not considered safe.

Quick and Dirty

The quick way is to create an object directly. This works, but it has potential problems with used against a powerful optimized such as the Google Closure Compiler.

All the Quick and Dirty examples can make use of this in their myFunc examples. However, the closure compiler will warning about all of them because it doesn't know for ...

tripwire while updating the policy settings: Error: Policy Update Changed Object.

As I was trying to remove some annoying entries in my Tripwire policy, I started getting errors. The first time I did not pay close attention, but the next day the policy had not changed! So I looked at it closer and noticed that if a file changed since the last update, then tripwire refuses to update the policy. That is, if the secure mode is set to high.

So to update my tripwire policy I was running:

sudo tripwire -m p -p /etc/tripwire/tw.pol --secure-mode low /etc/tripwire/twpol.txt

which now (at least since 13.04, maybe in 12.10?) means the secure mode is left alone and is marked as ...

Using QDateTime to output a date string and UTC

As I'm working on a server I need dates in UTC. By default, the QDateTime object generates dates in local time.

How do you change that? There is a toUTC() but my input data is already UTC so using toUTC() would mess up the date and I'd get the same result anyway.

The idea is actually pretty simple. The toUTC() creates a QDateTime object in UTC mode. This is done like this:

QDateTime utc(QDateTime().toUTC());

Now the utc object is in UTC mode and can be used with your Unix dates as in:

utc.setTime_t(time(NULL));

and the string output can be generated with toString() as in:

 ...

Designing a rotating wheel to ask users to wait while working in the background

Large version of the waiting wheelAs I'm working on a new feature for our Snap! Website system I wanted to have a turning wheel that asks users to wait while the computer does work.

The graphic is very simple: a rectangle with a border and a background color that rotates. However, I do not have a tool (that I know of) which could create the graphics automatically. So I did it with quite a bit of manual labor, but it was fun to learn a few things along the way.

I use inkscape to create such graphics. First I created the rectangle on the left. With that I had to have it rotated going 360 degrees repeating the rectangle 24 ...

MS-Access: Application-defined or object defined error

Today I got this weird error: Application-defined or object defined error.

Looking into it, I could not find the right answer.

The failing code was in a sub-form and when called it generated the error immediately. The code I wrote was:

Parent.NewSelection

And of course, in the parent I had the NewSelection function defined:

Private Sub NewSelection
    DoSomething
End Sub

The DoSomething would update a button as required...

For real MS-Access pros, you may already have noticed what the problem was. What's really annoying is that the error we get is not capable of telling ...

The C++ delete operator, will it do what you expect?

It has always been weird to me to see that the delete operator was not actually going to call all the destructor on objects. That is, if you create a class B that derives from a class A, deleting an object when cast to A does not (by default) call the destructor defined in class B.

The result is that ALL classes should define their destructor as virtual. This doesn't make sense because you shouldn't have to have a virtual table in all your objects just for the destructor to work right. On the other hand, class A has no way to know that it will be derived by class B so its destructor

unresolved external symbol "public: virtual struct QMetaObject const *__thiscall MyClass::metaObject[...]"

Got a problem with Qt today... and it took me a little time to figure out again and I'm sure some people have something about it, but I couldn't find the right answer anywhere.

Qt has those objects named QObject. You can derive them that class and to complete the object, you want to add a Q_OBJECT inside the class. Something like this:

  class MyClass : public QObject
  {
    Q_OBJECT
    [...your object definitions...]
  };

That Q_OBJECT is what makes your object visible in the Qt environment (i.e. a Find by name will find your object if you give it a name with setObjectName().

QtTest and "Cannot create a QWidget when no GUI is being used"

Problem

I have to use Qt these days. It's a good system, but there are a few tricks to know about.

As I was starting to write a test, the test needed a lot of numbers but nothing much otherwise. So I decided to limit the #include to a minimum by deleting all of those that I did not need.

The result was this error:

"Cannot create a QWidget when no GUI is being used"

I looked into it and sure enough people talking about it say: Well... where is your GUI?

Great, but I don't see how that helps me in fixing the problem, does it do it for you? Neither?!

Solution

...

MS-Access variable types that do not exist?!

Problem

I worked on a project with many functions that access the database. These functions will generally have a Recordset variable. Yet, when I tried to run a script with the recordset declaration, it would fail with the error Undefined variable type.

  Dim rcd As Recordset

Since that definition was not required for the software to work, I ignored the error for a long time.

Syndicate content Syndicate content

SMS From Me Logo

SMS From Me

To automatically start one on one conversations with your online leads.

     

   

Terms of Site Index

Find the page/content you are looking for with our index.

  • Internet Explorer

    Internet Explorer is the browser offered by Microsoft to browse your file system and the Internet. It is based on the old free software called Mosaic. Now it is borrowing parts of other free software such as Konqueror. It first used Visual Basic as a language, now it supports Javascript very well too. It was a great browser in competition with Netscape 5.x from the start (trying to undermine the company named Netscape.)

  • nested

    In computing, nested means an item defined inside another. It is most often used for loops, a loop can be declared inside another. The one inside is called the nested loop. In particular, two loops can be defined one after another or one inside the other. There is no other way to declare a loop.

  • option
  • support
  • variable