Widgets Reference

Widgets are report elements to show text values on report canvas.

All widget classes can be initialized with their attributes as class arguments.

Widget

class geraldo.widgets.Widget

Path: geraldo.widgets.Widget

Base class for reports widgets, you should use it only to inherit and make your own widgets, otherwise you shouldn’t use it directly.

Attributes

  • name - Default: None

  • height - Default: 0.5*cm

  • width - Default: 5*cm

  • left - Default: 0

  • top - Default: 0

  • visible - Default: True

    Set to False if you want to make it not visible.

  • borders - Default: {‘top’: None, ‘right’: None, ‘bottom’: None, ‘left’: None, ‘all’: None}

    Borders values can be of three types:

    • Boolean (True/False) - just set if there is a border or not
    • Integer - set there is a border and what is its stroke width. New on 0.4.
    • Graphic (instance of Rect, Line, RoundRect, etc.) - set a complex graphic to put along the border

  • style - Default: {}

    This is a dictionary that uses the powerful ReportLab ParagraphStyle class to set style settings for this widget.

    Default keys are:

    • fontName - Default: ‘Times-Roman’,
    • fontSize - Default: 10,
    • leading - Default: 12,
    • leftIndent - Default: 0,
    • rightIndent - Default: 0,
    • firstLineIndent - Default: 0,
    • alignment - Default: TA_LEFT,
    • spaceBefore - Default: 0,
    • spaceAfter - Default: 0,
    • bulletFontName - Default: ‘Times-Roman’,
    • bulletFontSize - Default: 10,
    • bulletIndent - Default: 0,
    • textColor - Default: black,
    • backColor - Default: None,
    • wordWrap - Default: None,
    • allowWidows - Default: 1,
    • allowOrphans - Default: 0,

  • get_value - Default: None.

    This is the way you can easily customize the widget output. Be careful with this attribute, because each widget has its own set of arguments.

  • truncate_overflow - Default: False

    When “True”, truncate the widget to use only its defined height and widget attributes, with no word wrap. This means that those attributes are required.

Events system

  • before_print - Default: None

    Is called by do_before_print method, before generate the widget output. Expect arguments widget and generator.

  • after_print - Default: None

    Is called by do_after_print method, after generate the widget output. Expect arguments widget and generator.

Rendering attributes

They are read-only attributes you can use at render time.

  • instance - current object being rendered
  • generator - generator instance
  • report - report instance this element is in
  • band - band this element is in
  • page - current page

Label

class geraldo.widgets.Label

Path: geraldo.Label

A label is just a simple text.

Example of use

>>> Label(text='Taxes we have paid', left=1*cm, top=0.5*cm, width=10*cm, height=0.5*cm)

Attributes

  • height - Default: 0.5*cm
  • width - Default: 5*cm
  • left - Default: 0
  • top - Default: 0
  • visible - Default: True
  • style - Default: {}

get_value must have a ‘text’ argument.

ObjectValue

class geraldo.widgets.ObjectValue

Path: geraldo.ObjectValue

This shows the value from a method, field or property from objects in the queryset.

You can provide an action to show the object value or an aggregation function on it.

You can also use the ‘display_format’ attribute to set a friendly string formatting, with a mask or additional text.

‘get_value’ lambda must have an ‘instance’ argument.

Example of use

>>> ObjectValue(attribute_name='name', left=1*cm, top=0.5*cm, width=10*cm, height=0.5*cm)

Attributes

  • height - Default: 0.5*cm

  • width - Default: 5*cm

  • left - Default: 0

  • top - Default: 0

  • visible - Default: True

  • style - Default: {}

  • attribute_name - Required

    You can provide here the object attribute name you want to show in this widget. You can provide a field, common attribute, property or just a method, since it has no required argument to provide.

    You can use paths of callable or properties instead of attribute name in this attribute.

    Examples:

    attribute_name = ‘name.upper’ attribute_name = ‘customer.name’ attribute_name = ‘customer.type.name.lower’

  • action - Default: geraldo.FIELD_ACTION_VALUE

    The action is where you say what Geraldo will do with the value of this field. The default action is just to show its value and nothing more.

    But if you are using an ObjectValue in a summary or footer band of report, group or subreport, you will probably have a need for aggregation functions. This is why this attribute exists.

    Field actions are all available in the geraldo package to import from. The choices you can use in action attributes are:

    • geraldo.FIELD_ACTION_VALUE
    • geraldo.FIELD_ACTION_COUNT
    • geraldo.FIELD_ACTION_AVG
    • geraldo.FIELD_ACTION_MIN
    • geraldo.FIELD_ACTION_MAX
    • geraldo.FIELD_ACTION_SUM
    • geraldo.FIELD_ACTION_DISTINCT_COUNT

  • display_format - Default: ‘%s’

    Use simple string formatting on the field value. You could otherwise use get_value if you want something more powerful.

  • get_text - Default: None.

    This ‘lambda’ attribute is seemed to get_value because it works after value getting. It’s important to keep aware there are two moments from get a value from instance until to render it on the output generation:

      1. First the value is getted (and keeps being an unformatted value)
      1. After this, the value is formatted (and transformed to unicode string)

  • stores_text_in_cache - Default: True

    This is a boolean attribute you can set to False if you to force the text getting to run twice: on renderizing and on generating. If you keep it as True, it will store the text on the first getting and use the stored text on next time(s) it be requested.

SystemField

class geraldo.widgets.SystemField

Path: geraldo.SystemField

This shows system information, like the report title, current date/time, page number, page count, etc.

‘get_value’ must have ‘expression’ and ‘fields’ arguments.

Example of use

>>> ObjectValue(expression='%(report_title)s', left=1*cm, top=0.5*cm, width=10*cm, height=0.5*cm)

Attributes

  • height - Default: 0.5*cm

  • width - Default: 5*cm

  • left - Default: 0

  • top - Default: 0

  • visible - Default: True

  • style - Default: {}

  • expression - Default: ‘%(report_title)s’

    This is a simple string you can write with basic macros to show system field values.

    The available macros are:

    • %(report_title)s

    • %(page_number)s

    • %(first_page_number)s

    • %(last_page_number)s

    • %(page_count)s

    • %(report_author)s

    • %(now:FORMAT)s - in replace of ‘FORMAT’ you can use date formatting standard template filter date formatting. But if you are using your own Report.format_date method, this will use it.

      Examples:

      • ‘%(now:%Y)’ - shows the current year
      • ‘%(now:%m/%d/%Y)’ - shows something like ‘01/23/2009’

      Note: this is changed now. Before this function used Django template filter ‘date’ to format datetime, but once we were going to use two standards, this wouldn’t be nice. If you want to use Django’s template filter, you can override the method Report.format_date(date, expression) and use it.