The html library provides classes for parsing and displaying HTML.
It is not intended to be a high-end HTML browser. If you are looking for something like that try http://www.mozilla.org/.
html can be used as a generic rich text viewer - for example to display a nice About Box (like those of GNOME apps) or to display the result of database searching. There is a FileSystem class which allows you to use your own virtual file systems.
mywin.LoadPage("test.htm") mywin.SetPage("htmlbody" \ "h1Error/h1" \ "Some error occurred :-H)" \ "/body/hmtl")
Because HtmlWindow is derived from ScrolledWindow and not from Frame, it doesn’t have visible frame. But the user usually wants to see the title of HTML page displayed somewhere and the frame’s titlebar is the ideal place for it.
html = wx.html.HtmlWindow(self) html.SetRelatedFrame(self, "HTML : %%s") html.SetRelatedStatusBar(0)
The first command associates the HTML object with its parent frame (this points to Frame object there) and sets the format of the title. Page title “Hello, world!” will be displayed as “HTML : Hello, world!” in this example.
The second command sets which frame’s status bar should be used to display browser’s messages (such as “Loading...” or “Done” or hypertext links).
You can customize HtmlWindow by setting font size, font face and borders (space between border of window and displayed HTML). Related functions:
The last two functions are used to store user customization info ConfigBase stuff (for example in the registry under Windows, or in a dotfile under Unix).
It lets you print HTML documents with only one command and you don’t have to worry about deriving from the Printout class at all. It is only a simple wrapper around the HtmlPrintout, normal wxPython printout class.
And finally there is the low level class HtmlDCRenderer which you can use to render HTML into a rectangular area on any DC.
It supports rendering into multiple rectangles with the same width. (The most common use of this is placing one rectangle on each page or printing into two columns.)
A book consists of three files: the header file, the contents file and the index file.
You can make a regular zip archive of these files, plus the HTML and any image files, for HTML (or helpview) to read; and the ".zip" file can optionally be renamed to ".htb".
The header file must contain these lines (and may contain additional lines which are ignored):
Contents file=filename.hhc Index file=filename.hhk Title=title of your book Default topic=default page to be displayed.htm
All filenames (including the Default topic) are relative to the location of the ".hhp" file.
For localization, in addition the ".hhp" file may contain the line:
which specifies what charset (e.g. “iso8859_1”) was used in contents and index files. Please note that this line is incompatible with MS HTML Help Workshop and it would either silently remove it or complain with some error.
Contents file has HTML syntax and it can be parsed by regular HTML parser. It contains exactly one list (<ul> ... </ul> statement):
<ul> <li><object type="text/sitemap"> <param name="Name" value="@topic name@"> <param name="ID" value=@numeric_id@> <param name="Local" value="@filename.htm@"> </object></li> <li><object type="text/sitemap"> <param name="Name" value="@topic name@"> <param name="ID" value=@numeric_id@> <param name="Local" value="@filename.htm@"> </object></li> </ul>
You can modify value attributes of param tags. The topic name is name of chapter/topic as is displayed in contents, filename.htm is the HTML page name (relative to the ".hhp" file) and numeric_id is optional - it is used only when you use Display.
Items in the list may be nested - one <li> statement may contain a <ul> sub-statement:
<ul> <li><object type="text/sitemap"> <param name="Name" value="Top node"> <param name="Local" value="top.htm"> </object></li> <ul> <li><object type="text/sitemap"> <param name="Name" value="subnode in topnode"> <param name="Local" value="subnode1.htm"> </object></li> </ul> <li><object type="text/sitemap"> <param name="Name" value="Another Top"> <param name="Local" value="top2.htm"> </object></li> </ul>
Index files have same format as contents files except that ID params are ignored and sublists are not allowed.
The html library provides a mechanism for reading and displaying files of many different file formats.
You can divide any text (or HTML) into small fragments. Let’s call these fragments cells. Cell is for example one word, horizontal line, image or any other part of document. Each cell has width and height (except special “magic” cells with zero dimensions - e.g. colour changers or font changers). See HtmlCell.
Container is kind of cell that may contain sub-cells. Its size depends on number and sizes of its sub-cells (and also depends on width of window). See HtmlContainerCell, Layout. This image shows the cells and containers:
HtmlWinParser provides a user-friendly way of managing containers. It is based on the idea of opening and closing containers.
Use OpenContainer to open new a container within an already opened container. This new container is a sub-container of the old one. (If you want to create a new container with the same depth level you can call CloseContainer(); OpenContainer(); ).
Use CloseContainer to close the container. This doesn’t create a new container with same depth level but it returns “control” to the parent container. See explanation:
There clearly must be same number of calls to OpenContainer as to CloseContainer.
This code creates a new paragraph (container at same depth level) with “Hello, world!”:
myParser.CloseContainer() c = myParser.OpenContainer() myParser.AddText("Hello, ") myParser.AddText("world!") myParser.CloseContainer() myParser.OpenContainer()
and here is image of the situation:
You can see that there was an opened container before the code was executed. We closed it, created our own container, then closed our container and opened new container.
The result was that we had same depth level after executing. This is general rule that should be followed by tag handlers: leave depth level of containers unmodified (in other words, number of OpenContainer and CloseContainer calls should be same within HandleTag ‘s body).
Notice that it would be usually better to use InsertCell instead of adding text to the parser directly.
The html library provides architecture of pluggable tag handlers. Tag handler is class that understands particular HTML tag (or tags) and is able to interpret it.
HtmlWinParser has a static table of modules. Each module contains one or more tag handlers. Each time a new HtmlWinParser object is constructed all modules are scanned and handlers are added to HtmlParser’s list of available handlers.
Common tag handler’s HandleTag method works in four steps:
See HtmlWinParser for methods for modifying parser’s state. In general you can do things like opening/closing containers, changing colors, fonts etc...