Doc/lib/libwebbrowser.tex

   1 \section{\module{webbrowser} ---
   2          Convenient Web-browser controller}
   3
   4 \declaremodule{standard}{webbrowser}
   5 \modulesynopsis{Easy-to-use controller for Web browsers.}
   6 \moduleauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
   7 \sectionauthor{Fred L. Drake, Jr.}{fdrake@acm.org}
   8
   9 The \module{webbrowser} module provides a very high-level interface to
  10 allow displaying Web-based documents to users.  The controller objects
  11 are easy to use and are platform-independent.  Under most
  12 circumstances, simply calling the \function{open()} function from this
  13 module will do the right thing.
  14
  15 Under \UNIX, graphical browsers are preferred under X11, but text-mode
  16 browsers will be used if graphical browsers are not available or an X11
  17 display isn't available.  If text-mode browsers are used, the calling
  18 process will block until the user exits the browser.
  19
  20 Under \UNIX, if the environment variable \envvar{BROWSER} exists, it
  21 is interpreted to override the platform default list of browsers, as a
  22 colon-separated list of browsers to try in order.  When the value of
  23 a list part contains the string \code{\%s}, then it is interpreted as
  24 a literal browser command line to be used with the argument URL
  25 substituted for the \code{\%s}; if the part does not contain
  26 \code{\%s}, it is simply interpreted as the name of the browser to
  27 launch.
  28
  29 For non-\UNIX{} platforms, or when X11 browsers are available on
  30 \UNIX, the controlling process will not wait for the user to finish
  31 with the browser, but allow the browser to maintain its own window on
  32 the display.
  33
  34 The following exception is defined:
  35
  36 \begin{excdesc}{Error}
  37   Exception raised when a browser control error occurs.
  38 \end{excdesc}
  39
  40 The following functions are defined:
  41
  42 \begin{funcdesc}{open}{url\optional{, new=0}\optional{, autoraise=1}}
  43   Display \var{url} using the default browser.  If \var{new} is true,
  44   a new browser window is opened if possible.  If \var{autoraise} is
  45   true, the window is raised if possible (note that under many window
  46   managers this will occur regardless of the setting of this variable).
  47 \end{funcdesc}
  48
  49 \begin{funcdesc}{open_new}{url}
  50   Open \var{url} in a new window of the default browser, if possible,
  51   otherwise, open \var{url} in the only browser window.
  52 \end{funcdesc}
  53
  54 \begin{funcdesc}{get}{\optional{name}}
  55   Return a controller object for the browser type \var{name}.  If
  56   \var{name} is empty, return a controller for a default browser
  57   appropriate to the caller's environment.
  58 \end{funcdesc}
  59
  60 \begin{funcdesc}{register}{name, constructor\optional{, instance}}
  61   Register the browser type \var{name}.  Once a browser type is
  62   registered, the \function{get()} function can return a controller
  63   for that browser type.  If \var{instance} is not provided, or is
  64   \code{None}, \var{constructor} will be called without parameters to
  65   create an instance when needed.  If \var{instance} is provided,
  66   \var{constructor} will never be called, and may be \code{None}.
  67
  68   This entry point is only useful if you plan to either set the
  69   \envvar{BROWSER} variable or call \function{get} with a nonempty
  70   argument matching the name of a handler you declare.
  71 \end{funcdesc}
  72
  73 A number of browser types are predefined.  This table gives the type
  74 names that may be passed to the \function{get()} function and the
  75 corresponding instantiations for the controller classes, all defined
  76 in this module.
  77
  78 \begin{tableiii}{l|l|c}{code}{Type Name}{Class Name}{Notes}
  79   \lineiii{'mozilla'}{\class{Netscape('mozilla')}}{}
  80   \lineiii{'netscape'}{\class{Netscape('netscape')}}{}
  81   \lineiii{'mosaic'}{\class{GenericBrowser('mosaic \%s \&')}}{}
  82   \lineiii{'kfm'}{\class{Konqueror()}}{(1)}
  83   \lineiii{'grail'}{\class{Grail()}}{}
  84   \lineiii{'links'}{\class{GenericBrowser('links \%s')}}{}
  85   \lineiii{'lynx'}{\class{GenericBrowser('lynx \%s')}}{}
  86   \lineiii{'w3m'}{\class{GenericBrowser('w3m \%s')}}{}
  87   \lineiii{'windows-default'}{\class{WindowsDefault}}{(2)}
  88   \lineiii{'internet-config'}{\class{InternetConfig}}{(3)}
  89 \end{tableiii}
  90
  91 \noindent
  92 Notes:
  93
  94 \begin{description}
  95 \item[(1)]
  96 ``Konqueror'' is the file manager for the KDE desktop environment for
  97 UNIX, and only makes sense to use if KDE is running.  Some way of
  98 reliably detecting KDE would be nice; the \envvar{KDEDIR} variable is
  99 not sufficient.  Note also that the name ``kfm'' is used even when
 100 using the \program{konqueror} command with KDE 2 --- the
 101 implementation selects the best strategy for running Konqueror.
 102
 103 \item[(2)]
 104 Only on Windows platforms; requires the common
 105 extension modules \module{win32api} and \module{win32con}.
 106
 107 \item[(3)]
 108 Only on MacOS platforms; requires the standard MacPython \module{ic}
 109 module, described in the \citetitle[../mac/module-ic.html]{Macintosh
 110 Library Modules} manual.
 111 \end{description}
 112
 113
 114 \subsection{Browser Controller Objects \label{browser-controllers}}
 115
 116 Browser controllers provide two methods which parallel two of the
 117 module-level convenience functions:
 118
 119 \begin{funcdesc}{open}{url\optional{, new}}
 120   Display \var{url} using the browser handled by this controller.  If
 121   \var{new} is true, a new browser window is opened if possible.
 122 \end{funcdesc}
 123
 124 \begin{funcdesc}{open_new}{url}
 125   Open \var{url} in a new window of the browser handled by this
 126   controller, if possible, otherwise, open \var{url} in the only
 127   browser window.
 128 \end{funcdesc}