FileType

This class holds information about a given file type.

File type is the same as MIME type under Unix, but under Windows it corresponds more to an extension than to MIME type (in fact, several extensions may correspond to a file type).

This object may be created in several different ways: the program might know the file extension and wish to find out the corresponding MIME type or, conversely, it might want to find the right extension for the file to which it writes the contents of given MIME type. Depending on how it was created some fields may be unknown so the return value of all the accessors must be checked: False will be returned if the corresponding information couldn’t be found.

The objects of this class are never created by the application code but are returned by MimeTypesManager.GetFileTypeFromMimeType and MimeTypesManager.GetFileTypeFromExtension methods. But it is your responsibility to delete the returned pointer when you’re done with it!

A brief reminder about what the MIME types are (see the RFC 1341 for more information): basically, it is just a pair category/type (for example, “text/plain”) where the category is a basic indication of what a file is. Examples of categories are “application”, “image”, “text”, “binary”, and type is a precise definition of the document format: “plain” in the example above means just ASCII text without any formatting, while “text/html” is the HTML document source.

A MIME type may have one or more associated extensions: “text/plain” will typically correspond to the extension ”.txt”, but may as well be associated with ”.ini” or ”.conf”.

MessageParameters class

One of the most common usages of MIME is to encode an e-mail message. The MIME type of the encoded message is an example of a message parameter. These parameters are found in the message headers (“Content-XXX”). At the very least, they must specify the MIME type and the version of MIME used, but almost always they provide additional information about the message such as the original file name or the charset (for the text documents). These parameters may be useful to the program used to open, edit, view or print the message, so, for example, an e-mail client program will have to pass them to this program. Because FileType itself cannot know about these parameters, it uses MessageParameters class to query them. The default implementation only requires the caller to provide the file name (always used by the program to be called - it must know which file to open) and the MIME type and supposes that there are no other parameters. If you wish to supply additional parameters, you must derive your own class from MessageParameters and override GetParamValue() function, for example:

# provide the message parameters for the MIME type manager
class MailMessageParameters(wx.FileType.MessageParameters):

    def __init__(self, filename, mimetype):

        wx.FileType.MessageParameters.__init__(self, filename, mimetype)


    def GetParamValue(self, name):

        # parameter names are not case-sensitive
        if name.lower() == "charset":
            return "US-ASCII"
        else:
            return wx.FileType.MessageParameters.GetParamValue(name)

Now you only need to create an object of this class and pass it to, for example, GetOpenCommand like this:

if filetype.GetOpenCommand(MailMessageParameters("foo.txt", "text/plain")):

    # the full command for opening the text documents is in 'command'
    # (it might be "notepad foo.txt" under Windows or "cat foo.txt" under Unix)
    HandleCommand()

else:

    # we don't know how to handle such files...
    pass

Windows: As only the file name is used by the program associated with the given extension anyhow (but no other message parameters), there is no need to ever derive from MessageParameters class for a Windows-only program.

See also

MimeTypesManager

Inheritance Diagram

Inheritance diagram for class FileType

Methods Summary

__init__	Copy constructor.
ExpandCommand	This function is primarily intended for GetOpenCommand and GetPrintCommand usage but may be also used by the application directly if, for example, you want to use some non-default command to open the file.
GetAllCommands	Returns the number of commands for this mime type, and fills the verbs and commands arrays with the command information.
GetIconLocation	Returns a wx.IconLocation that can be used to fetch the icon for this mime type.
GetOpenCommand	With the first version of this method, if the True is returned, the string pointed to by command is filled with the command which must be executed (see Execute) in order to open the file of the given type.

Properties Summary

Description	See GetDescription
Extensions	See GetExtensions
Icon	See GetIcon
IconLocation	See GetIconLocation
MimeType	See GetMimeType
MimeTypes	See GetMimeTypes
OpenCommand	See GetOpenCommand
PrintCommand	See GetPrintCommand

Class API

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class FileType(object)

This class holds information about a given file type.

Possible constructors:

FileType(ftInfo)

Methods

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__init__(self, ftInfo)

Copy constructor.

Parameters:ftInfo (FileTypeInfo) –

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static ExpandCommand(command, params)

This function is primarily intended for GetOpenCommand and GetPrintCommand usage but may be also used by the application directly if, for example, you want to use some non-default command to open the file.

The function replaces all occurrences of:

• s with the full file name
• t with the MIME type
• %{param} with the value of the parameter param using the MessageParameters object you pass to it.

If there is no ‘s’ in the command string (and the string is not empty), it is assumed that the command reads the data on stdin and so the effect is the same as ” %s” were appended to the string.

Unlike all other functions of this class, there is no error return for this function.

Parameters:

• command (string) –
• params (MessageParameters) –

Return type:

string

---

GetAllCommands(self, params)

Returns the number of commands for this mime type, and fills the verbs and commands arrays with the command information.

Parameters:params (FileType.MessageParameters) – Return type:tuple Returns:( size_t, verbs, commands )

---

GetIconLocation(self)

Returns a wx.IconLocation that can be used to fetch the icon for this mime type.

Return type: IconLocation

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GetOpenCommand(self, *args, **kw)

Overloaded Implementations:

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GetOpenCommand (self, filename)

With the first version of this method, if the True is returned, the string pointed to by command is filled with the command which must be executed (see Execute) in order to open the file of the given type.

In this case, the name of the file as well as any other parameters is retrieved from MessageParameters() class.

In the second case, only the filename is specified and the command to be used to open this kind of file is returned directly. An empty string is returned to indicate that an error occurred (typically meaning that there is no standard way to open this kind of files).

Parameters:filename (string) – Return type:string

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GetOpenCommand (self, params)

Returns the command which must be executed (see wx.Execute()) in order to open the file of the given type. The name of the file as well as any other parameters is retrieved from MessageParameters() class.

Return type:string

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Properties

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Description

See GetDescription

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Extensions

See GetExtensions

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Icon

See GetIcon

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IconLocation

See GetIconLocation

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MimeType

See GetMimeType

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MimeTypes

See GetMimeTypes

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OpenCommand

See GetOpenCommand

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PrintCommand

See GetPrintCommand