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10.10.3. The Writer Interface

Interfaces to create writers are dependent on the specific writer class being instantiated. The interfaces described below are the required interfaces which all writers must support once initialized. Note that while most applications can use the AbstractFormatter class as a formatter, the writer must typically be provided by the application.

new_alignment (align) -- Method on writer object
Set the alignment style. The align value can be any object, but by convention is a string or None, where None indicates that the writer's ``preferred'' alignment should be used. Conventional align values are 'left', 'center', 'right', and 'justify'.
new_font (font) -- Method on writer object
Set the font style. The value of font will be None, indicating that the device's default font should be used, or a tuple of the form (size, italic, bold, teletype). Size will be a string indicating the size of font that should be used; specific strings and their interpretation must be defined by the application. The italic, bold, and teletype values are boolean indicators specifying which of those font attributes should be used.
new_margin (margin, level) -- Method on writer object
Set the margin level to the integer level and the logical tag to margin. Interpretation of the logical tag is at the writer's discretion; the only restriction on the value of the logical tag is that it not be a false value for non-zero values of level.
new_spacing (spacing) -- Method on writer object
Set the spacing style to spacing.
new_styles (styles) -- Method on writer object
Set additional styles. The styles value is a tuple of arbitrary values; the value AS_IS should be ignored. The styles tuple may be interpreted either as a set or as a stack depending on the requirements of the application and writer implementation.
send_line_break () -- Method on writer object
Break the current line.
send_paragraph (blankline) -- Method on writer object
Produce a paragraph separation of at least blankline blank lines, or the equivelent. The blankline value will be an integer.
send_hor_rule (*args, **kw) -- Method on writer object
Display a horizontal rule on the output device. The arguments to this method are entirely application- and writer-specific, and should be interpreted with care. The method implementation may assume that a line break has already been issued via send_line_break().
send_flowing_data (data) -- Method on writer object
Output character data which may be word-wrapped and re-flowed as needed. Within any sequence of calls to this method, the writer may assume that spans of multiple whitespace characters have been collapsed to single space characters.
send_literal_data (data) -- Method on writer object
Output character data which has already been formatted for display. Generally, this should be interpreted to mean that line breaks indicated by newline characters should be preserved and no new line breaks should be introduced. The data may contain embedded newline and tab characters, unlike data provided to the send_formatted_data() interface.
send_label_data (data) -- Method on writer object
Set data to the left of the current left margin, if possible. The value of data is not restricted; treatment of non-string values is entirely application- and writer-dependent. This method will only be called at the beginning of a line.