I am working on a project which has a PDF editor that we have built in angular. User can drag and drop dynamic fields (user defined fields) on the PDF. These fields when are filled from a user define form, the corresponding PDF (that user has edited) gets generated in the backend. We are using Python 3.7 and Reportlab to edit and write dynamic data to the PDF.
The length of the value dynamic fields is not fixed. It can be more than the field variable's length. On PDF editor, the user decides max width of the generated dynamic text. We want to write the text till the specified width only and truncate rest of the text. For example, first_name is the variable dropped on the PDF editor. It's max width is set to 10px. If the value of the variable is "Wolfeschlegelsteinhausenbergerdorff", the text should be written till 10 px and should get truncated after that.
So far, we have managed to write the full text (irrespective of width specified). Following is the code that we are using.
........
paragraph_style.textColor = HexColor(pdf_element["font_color"])
paragraph_style.fontSize = pdf_element["font_size"]
paragraph = Paragraph(str(output_text_value), style=paragraph_style)
paragraph.drawOn(can,location_x, location_y)
........
Above code writes full text on the PDF. However, we need a way to somehow truncate the text after specified width.
Any help is greatly appreciated.
Instead of directly drawing paragraph on the canvas, use frame. Add the paragraph inside frame, Apply truncate mode to the frame and then draw frame on canvas. Your code should look like following:
frame = KeepInFrame(min_width, min_height, [paragraph], mode='truncate')
frame.width = float(min_.replace("px",""))
frame.drawOn(can, location_x, location_y)
Hope it helps. Thanks