MACROMEDIA COLDFUSION 4.5-CFML LANGUAGE Manual do Utilizador descarregar pdf (Página 34)

34 CHAPTER 30 Extending ColdFusion with CFX

NOTE

The atof() function returns 0 if it encounters a string that can’t be parsed into a number. It doesn’t generate an error. This means

that this CFX tag will treat anything other than a number as a 0, which will affect the tag’s computations. In other words, the tag is

smart enough to skip over null values, but it is not smart enough to skip over other non-numeric data points. This should not be a

problem because a column would not typically include both numbers and strings.

Compiling Your New CFX Tag

To compile the tag, simply choose the Build option from the Build menu in Visual C++, or use the

Build toolbar button. Assuming there are no syntax or other problems with the code, the compiler

should be able to compile the tag in a few seconds. The result will be a Dynamic Link Library (.dll)

ﬁle, located in either the project\Debug or project\Release subfolder of Visual Studio’s My Projects

folder (where the project part is most likely the name of your CFX tag).

It’s worth noting that you will be building a Debug version of the DLL by default. I recommend

switching to the Win32 Release conﬁguration before compiling the tag. You may use the default

Win32 Debug conﬁguration if you wish during testing, but you will probably be doing most of your

debugging via

pRequest->WriteDebug() rather than conventional debugging methods, so the Win32

Debug build is unlikely to do you much good in terms of actual debugging. To switch to the Win32

Release conﬁguration, choose Build, Set Active Conﬁguration from the Visual C++ menu.

NOTE

Either type of build should perform the same way in your ColdFusion pages, but the debug version will be larger and cannot be

deployed to ColdFusion servers that don’t contain Microsoft’s debugging symbols. In general, the debugging symbols are only

installed on machines that have Visual C++ installed on them, which means that debug builds of CFX tags will probably only work on

the ColdFusion server installed on your local machine (if any).

Registering the New Tag

Once the tag has been compiled, you need to register it in the ColdFusion Administrator. The reg-

istration process is simple and very similar to the process for Java CFX tags. Just follow these steps:

1. Open the ColdFusion Administrator and navigate to the CFX Tags page.

Click the Register C++ CFX button. The Add/Edit C++ CFX Tag page appears (Figure 30.9).

3. In the Tag Name ﬁeld, enter the name of the tag, including the CFX_ part. This does not

have to be the same as the tag name you used while creating the C++ code, but I

recommend that you keep them consistent to keep from getting confused. The tag name

is not case sensitive.

4. In the Server Library ﬁeld, provide the location of the .dll ﬁle that represents the compiled

version of your CFX tag. If you are registering the tag on a ColdFusion server installed

on the same machine that you compiled the tag on, you can just specify the DLL’s current

location within Visual Studio’s directory tree. That way, whenever you rebuild the tag,

the server will automatically be looking at the newly built version. If the server is not on

your local development machine, you will need to copy the DLL to the server’s local

drive ﬁrst (you can place the DLL in whatever location you wish).

1 2 ... 29 30 31 32 33 34 35 36 37 38 39 ... 43 44

Sem comentários

MACROMEDIA COLDFUSION 4.5-CFML LANGUAGE Manual do Utilizador Página 34