Layout of pages


A Container manages how the contents of an HTMLElement fills the available width. The contents can be confined to a fixed width (with margins), or the contents can be fluid and expand to fill the whole width.

Sites with fluid and fixed containers showing how the contents stretch to fill the viewport or not.

Fluid vs fixed containers on a site.

Different areas of a page may be laid out using different Containers. For example, a header and footer area that both stretch the entire viewport width, with a centered, fixed content area inbetween.

Responsive layouts

A responsive layout arranges its contents differently, depending on the size of the device it is being displayed on.

For example, a Nav with many options displays on a cellphone as a list of options stacked op top of one another. On a large screen, it spreads the options in one row across the screen.

Use a ColumnLayout to control how your layout adapts to different sizes of device.

A ColumnLayout adds a number of visual columns to a Div. Add Widgets into each of the columns to control where they will display. The width of each column is stated in 1/12ths of the total width of the containing Div. If the total width of all the columns is more than 12/12ths, the extra columns flow over to a new line.

A ResponsiveSize contains all the different sizes to use for a column on different devices.


Columns with ResponsiveSize(lg=6) on a large device, defaulting to 12/12ths on a small device.

Add columns by giving a ColumnOptions instance for each column when creating the ColumnLayout:

    def add_four(self):
        layout = ColumnLayout(ColumnOptions('first', ResponsiveSize(md=6)),
                              ColumnOptions('second', ResponsiveSize(md=6)),
                              ColumnOptions('third', ResponsiveSize(md=6)),
                              ColumnOptions('fourth', ResponsiveSize(md=6)))

        div = Div(self.view).use_layout(layout)

        message = '6/12ths on md and larger, else defaults to 12/12ths'
        div.layout.columns['first'].add_child(P(self.view, text=message))
        div.layout.columns['second'].add_child(P(self.view, text=message))
        div.layout.columns['third'].add_child(P(self.view, text=message))
        div.layout.columns['fourth'].add_child(P(self.view, text=message))

Columns can also be created after the ColumnLayout has been applied:

    def add_twelve(self):
        div = Div(self.view).use_layout(ColumnLayout())

        for i in range(1, 13):
            column = div.layout.add_column(str(i), size=ResponsiveSize(md=1))
            column.add_child(P(self.view, text='1/12th on md and larger'))


ColumnLayouts need to be nested inside something with a Container layout.

Laying out a whole page

A PageLayout prepares a page so it has a header area at the top, a footer at the bottom, and a content area in between.

Use a PageLayout in conjunction with with a suitable ColumnLayout to further split the content area into different columns.

class PageLayoutPage(HTML5Page):
    def __init__(self, view):
        column_layout = ColumnLayout(ColumnOptions('left', ResponsiveSize(md=4)),
                                     ColumnOptions('right', ResponsiveSize(md=8)))

        self.layout.header.add_child(P(view, text='The header'))
        self.layout.footer.add_child(P(view, text='The footer'))

        left = column_layout.columns['left']
        left.add_child(P(view, text='To the left'))

        right = column_layout.columns['right']
        right.add_child(P(view, text='To the right'))