#Copyright ReportLab Europe Ltd. 2000-2004 #see license.txt for license details #history http://www.reportlab.co.uk/cgi-bin/viewcvs.cgi/public/reportlab/trunk/reportlab/docs/userguide/ch6_tables.py from reportlab.tools.docco.rl_doc_utils import * from reportlab.platypus import Image import reportlab heading1("Tables and TableStyles") disc(""" The $Table$ and $LongTable$ classes derive from the $Flowable$ class and are intended as a simple textual gridding mechanisms. The $longTable$ class uses a greedy algorithm when calculating column widths and is intended for long tables where speed counts. $Table$ cells can hold anything which can be converted to a Python $string$ or $Flowables$ (or lists of $Flowables$). """) disc(""" Our present tables are a trade-off between efficient drawing and specification and functionality. We assume the reader has some familiarity with HTML tables. In brief, they have the following characteristics: """) bullet("""They can contain anything convertible to a string; flowable objects such as other tables; or entire sub-stories""") bullet("""They can work out the row heights to fit the data if you don't supply the row height. (They can also work out the widths, but generally it is better for a designer to set the width manually, and it draws faster).""") bullet("""They can split across pages if needed (see the canSplit attribute). You can specify that a number of rows at the top and bottom should be repeated after the split (e.g. show the headers again on page 2,3,4...)""") bullet("""For very wide tables, they can also split 'by column'. You can choose whether tou want to split down-and-across or across-and-down""") bullet("""They have a simple and powerful notation for specifying shading and gridlines which works well with financial or database tables, where you don't know the number of rows up front. You can easily say 'make the last row bold and put a line above it'""") bullet("""The style and data are separated, so you can declare a handful of table styles and use them for a family of reports. Styes can also 'inherit', as with paragraphs.""") disc("""There is however one main limitation compared to an HTML table. They define a simple rectangular grid. There is no simple row or column spanning; if you need to span cells, you must nest tables inside table cells instead or use a more complex scheme in which the lead cell of a span contains the actual contents.""") disc(""" $Tables$ are created by passing the constructor an optional sequence of column widths, an optional sequence of row heights, and the data in row order. Drawing of the table can be controlled by using a $TableStyle$ instance. This allows control of the color and weight of the lines (if any), and the font, alignment and padding of the text. A primitive automatic row height and or column width calculation mechanism is provided for. """) heading2('$Table$ User Methods') disc("""These are the main methods which are of interest to the client programmer.""") heading4("""$Table(data, colWidths=None, rowHeights=None, style=None, splitByRow=1, repeatRows=0, repeatCols=0)$""") disc("""The $data$ argument is a sequence of sequences of cell values each of which should be convertible to a string value using the $str$ function or should be a Flowable instance (such as a $Paragraph$) or a list (or tuple) of such instances. If a cell value is a $Flowable$ or list of $Flowables$ these must either have a determined width or the containing column must have a fixed width. The first row of cell values is in $data[0]$ i.e. the values are in row order. The $i$, $j$th. cell value is in $data[i][j]$. Newline characters $'\\n'$ in cell values are treated as line split characters and are used at draw time to format the cell into lines. """) disc("""The other arguments are fairly obvious, the $colWidths$ argument is a sequence of numbers or possibly $None$, representing the widths of the columns. The number of elements in $colWidths$ determines the number of columns in the table. A value of $None$ means that the corresponding column width should be calculated automatically.""") disc("""The $rowHeights$ argument is a sequence of numbers or possibly $None$, representing the heights of the rows. The number of elements in $rowHeights$ determines the number of rows in the table. A value of $None$ means that the corresponding row height should be calculated automatically.""") disc("""The $style$ argument can be an initial style for the table.""") disc("""The $splitByRow$ argument is only needed for tables both too tall and too wide to fit in the current context. In this case you must decide whether to 'tile' down and across, or across and then down. This parameter is a Boolean indicating that the $Table$ should split itself by row before attempting to split itself by column when too little space is available in the current drawing area and the caller wants the $Table$ to split.""") disc("""The $repeatRows$ and $repeatCols$ arguments specify the number of leading rows and columns that should be repeated when the $Table$ is asked to split itself.""") heading4('$Table.setStyle(tblStyle)$') disc(""" This method applies a particular instance of class $TableStyle$ (discussed below) to the $Table$ instance. This is the only way to get $tables$ to appear in a nicely formatted way. """) disc(""" Successive uses of the $setStyle$ method apply the styles in an additive fashion. That is, later applications override earlier ones where they overlap. """) heading2('$TableStyle$') disc(""" This class is created by passing it a sequence of commands, each command is a tuple identified by its first element which is a string; the remaining elements of the command tuple represent the start and stop cell coordinates of the command and possibly thickness and colors, etc. """) heading2("$TableStyle$ User Methods") heading3("$TableStyle(commandSequence)$") disc("""The creation method initializes the $TableStyle$ with the argument command sequence as an example:""") eg(""" LIST_STYLE = TableStyle( [('LINEABOVE', (0,0), (-1,0), 2, colors.green), ('LINEABOVE', (0,1), (-1,-1), 0.25, colors.black), ('LINEBELOW', (0,-1), (-1,-1), 2, colors.green), ('ALIGN', (1,1), (-1,-1), 'RIGHT')] ) """) heading3("$TableStyle.add(commandSequence)$") disc("""This method allows you to add commands to an existing $TableStyle$, i.e. you can build up $TableStyles$ in multiple statements. """) eg(""" LIST_STYLE.add('BACKGROUND', (0,0), (-1,0), colors.Color(0,0.7,0.7)) """) heading3("$TableStyle.getCommands()$") disc("""This method returns the sequence of commands of the instance.""") eg(""" cmds = LIST_STYLE.getCommands() """) heading2("$TableStyle$ Commands") disc("""The commands passed to $TableStyles$ come in three main groups which affect the table background, draw lines, or set cell styles. """) disc("""The first element of each command is its identifier, the second and third arguments determine the cell coordinates of the box of cells which are affected with negative coordinates counting backwards from the limit values as in Python indexing. The coordinates are given as (column, row) which follows the spreadsheet 'A1' model, but not the more natural (for mathematicians) 'RC' ordering. The top left cell is (0, 0) the bottom right is (-1, -1). Depending on the command various extra (???) occur at indices beginning at 3 on. """) heading3("""$TableStyle$ Cell Formatting Commands""") disc("""The cell formatting commands all begin with an identifier, followed by the start and stop cell definitions and the perhaps other arguments. the cell formatting commands are:""") eg(""" FONT - takes fontname, optional fontsize and optional leading. FONTNAME (or FACE) - takes fontname. FONTSIZE (or SIZE) - takes fontsize in points; leading may get out of sync. LEADING - takes leading in points. TEXTCOLOR - takes a color name or (R,G,B) tuple. ALIGNMENT (or ALIGN) - takes one of LEFT, RIGHT and CENTRE (or CENTER) or DECIMAL. LEFTPADDING - takes an integer, defaults to 6. RIGHTPADDING - takes an integer, defaults to 6. BOTTOMPADDING - takes an integer, defaults to 3. TOPPADDING - takes an integer, defaults to 3. BACKGROUND - takes a color. ROWBACKGROUNDS - takes a list of colors to be used cyclically. COLBACKGROUNDS - takes a list of colors to be used cyclically. VALIGN - takes one of TOP, MIDDLE or the default BOTTOM """) disc("""This sets the background cell color in the relevant cells. The following example shows the $BACKGROUND$, and $TEXTCOLOR$ commands in action:""") EmbeddedCode(""" data= [['00', '01', '02', '03', '04'], ['10', '11', '12', '13', '14'], ['20', '21', '22', '23', '24'], ['30', '31', '32', '33', '34']] t=Table(data) t.setStyle(TableStyle([('BACKGROUND',(1,1),(-2,-2),colors.green), ('TEXTCOLOR',(0,0),(1,-1),colors.red)])) """) disc("""To see the effects of the alignment styles we need some widths and a grid, but it should be easy to see where the styles come from.""") EmbeddedCode(""" data= [['00', '01', '02', '03', '04'], ['10', '11', '12', '13', '14'], ['20', '21', '22', '23', '24'], ['30', '31', '32', '33', '34']] t=Table(data,5*[0.4*inch], 4*[0.4*inch]) t.setStyle(TableStyle([('ALIGN',(1,1),(-2,-2),'RIGHT'), ('TEXTCOLOR',(1,1),(-2,-2),colors.red), ('VALIGN',(0,0),(0,-1),'TOP'), ('TEXTCOLOR',(0,0),(0,-1),colors.blue), ('ALIGN',(0,-1),(-1,-1),'CENTER'), ('VALIGN',(0,-1),(-1,-1),'MIDDLE'), ('TEXTCOLOR',(0,-1),(-1,-1),colors.green), ('INNERGRID', (0,0), (-1,-1), 0.25, colors.black), ('BOX', (0,0), (-1,-1), 0.25, colors.black), ])) """) heading3("""$TableStyle$ Line Commands""") disc(""" Line commands begin with the identifier, the start and stop cell coordinates and always follow this with the thickness (in points) and color of the desired lines. Colors can be names, or they can be specified as a (R, G, B) tuple, where R, G and B are floats and (0, 0, 0) is black. The line command names are: GRID, BOX, OUTLINE, INNERGRID, LINEBELOW, LINEABOVE, LINEBEFORE and LINEAFTER. BOX and OUTLINE are equivalent, and GRID is the equivalent of applying both BOX and INNERGRID. """) CPage(4.0) disc("""We can see some line commands in action with the following example. """) EmbeddedCode(""" data= [['00', '01', '02', '03', '04'], ['10', '11', '12', '13', '14'], ['20', '21', '22', '23', '24'], ['30', '31', '32', '33', '34']] t=Table(data,style=[('GRID',(1,1),(-2,-2),1,colors.green), ('BOX',(0,0),(1,-1),2,colors.red), ('LINEABOVE',(1,2),(-2,2),1,colors.blue), ('LINEBEFORE',(2,1),(2,-2),1,colors.pink), ]) """) disc("""Line commands cause problems for tables when they split; the following example shows a table being split in various positions""") EmbeddedCode(""" data= [['00', '01', '02', '03', '04'], ['10', '11', '12', '13', '14'], ['20', '21', '22', '23', '24'], ['30', '31', '32', '33', '34']] t=Table(data,style=[ ('GRID',(0,0),(-1,-1),0.5,colors.grey), ('GRID',(1,1),(-2,-2),1,colors.green), ('BOX',(0,0),(1,-1),2,colors.red), ('BOX',(0,0),(-1,-1),2,colors.black), ('LINEABOVE',(1,2),(-2,2),1,colors.blue), ('LINEBEFORE',(2,1),(2,-2),1,colors.pink), ('BACKGROUND', (0, 0), (0, 1), colors.pink), ('BACKGROUND', (1, 1), (1, 2), colors.lavender), ('BACKGROUND', (2, 2), (2, 3), colors.orange), ]) """) t=getStory()[-1] getStory().append(Spacer(0,6)) for s in t.split(4*inch,30): getStory().append(s) getStory().append(Spacer(0,6)) getStory().append(Spacer(0,6)) for s in t.split(4*inch,36): getStory().append(s) getStory().append(Spacer(0,6)) disc("""When unsplit and split at the first or second row.""") CPage(4.0) heading3("""Complex Cell Values""") disc(""" As mentioned above we can have complicated cell values including $Paragraphs$, $Images$ and other $Flowables$ or lists of the same. To see this in operation consider the following code and the table it produces. Note that the $Image$ has a white background which will obscure any background you choose for the cell. To get better results you should use a transparent background. """) import os, reportlab.platypus I = '../images/replogo.gif' EmbeddedCode(""" I = Image('%s') I.drawHeight = 1.25*inch*I.drawHeight / I.drawWidth I.drawWidth = 1.25*inch P0 = Paragraph(''' A paragraph 1''', styleSheet["BodyText"]) P = Paragraph(''' The ReportLab Left Logo Image''', styleSheet["BodyText"]) data= [['A', 'B', 'C', P0, 'D'], ['00', '01', '02', [I,P], '04'], ['10', '11', '12', [P,I], '14'], ['20', '21', '22', '23', '24'], ['30', '31', '32', '33', '34']] t=Table(data,style=[('GRID',(1,1),(-2,-2),1,colors.green), ('BOX',(0,0),(1,-1),2,colors.red), ('LINEABOVE',(1,2),(-2,2),1,colors.blue), ('LINEBEFORE',(2,1),(2,-2),1,colors.pink), ('BACKGROUND', (0, 0), (0, 1), colors.pink), ('BACKGROUND', (1, 1), (1, 2), colors.lavender), ('BACKGROUND', (2, 2), (2, 3), colors.orange), ('BOX',(0,0),(-1,-1),2,colors.black), ('GRID',(0,0),(-1,-1),0.5,colors.black), ('VALIGN',(3,0),(3,0),'BOTTOM'), ('BACKGROUND',(3,0),(3,0),colors.limegreen), ('BACKGROUND',(3,1),(3,1),colors.khaki), ('ALIGN',(3,1),(3,1),'CENTER'), ('BACKGROUND',(3,2),(3,2),colors.beige), ('ALIGN',(3,2),(3,2),'LEFT'), ]) t._argW[3]=1.5*inch """%I) heading3("""$TableStyle$ Span Commands""") disc("""Our $Table$ classes support the concept of spanning, but it isn't specified in the same way as html. The style specification """) eg(""" SPAN, (sc,sr), (ec,er) """) disc("""indicates that the cells in columns $sc$ - $ec$ and rows $sr$ - $er$ should be combined into a super cell with contents determined by the cell $(sc, sr)$. The other cells should be present, but should contain empty strings or you may get unexpected results. """) EmbeddedCode(""" data= [['Top\\nLeft', '', '02', '03', '04'], ['', '', '12', '13', '14'], ['20', '21', '22', 'Bottom\\nRight', ''], ['30', '31', '32', '', '']] t=Table(data,style=[ ('GRID',(0,0),(-1,-1),0.5,colors.grey), ('BACKGROUND',(0,0),(1,1),colors.palegreen), ('SPAN',(0,0),(1,1)), ('BACKGROUND',(-2,-2),(-1,-1), colors.pink), ('SPAN',(-2,-2),(-1,-1)), ]) """) disc("""notice that we don't need to be conservative with our $GRID$ command. The spanned cells are not drawn through. """) heading3("""Special $TableStyle$ Indeces""") disc("""In any style command the first row index may be set to one of the special strings $'splitlast'$ or $'splitfirst'$ to indicate that the style should be used only for the last row of a split table, or the first row of a continuation. This allows splitting tables with nicer effects around the split.""") heading1("""Other Useful $Flowables$""") heading2("""$Preformatted(text, style, bulletText = None, dedent=0)$""") disc(""" Creates a preformatted paragraph which does no wrapping, line splitting or other manipulations. No $XML$ style tags are taken account of in the text. If dedent is non zero $dedent$ common leading spaces will be removed from the front of each line. """) heading2("""$XPreformatted(text, style, bulletText = None, dedent=0, frags=None)$""") disc(""" This is a non rearranging form of the $Paragraph$ class; $XML$ tags are allowed in $text$ and have the same meanings as for the $Paragraph$ class. As for $Preformatted$, if dedent is non zero $dedent$ common leading spaces will be removed from the front of each line. """) EmbeddedCode(""" from reportlab.lib.styles import getSampleStyleSheet stylesheet=getSampleStyleSheet() normalStyle = stylesheet['Normal'] text=''' This is a non rearranging form of the Paragraph class; XML tags are allowed in text and have the same meanings as for the Paragraph class. As for Preformatted, if dedent is non zero dedent common leading spaces will be removed from the front of each line. You can have &amp; style entities as well for & < > and ". ''' t=XPreformatted(text,normalStyle,dedent=3) """) heading2("""$Image(filename, width=None, height=None)$""") disc("""Create a flowable which will contain the image defined by the data in file $filename$. The default PDF image type jpeg is supported and if the PIL extension to Python is installed the other image types can also be handled. If $width$ and or $height$ are specified then they determine the dimension of the displayed image in points. If either dimension is not specified (or specified as $None$) then the corresponding pixel dimension of the image is assumed to be in points and used. """) I=os.path.join(os.path.dirname(reportlab.__file__),'docs','images','lj8100.jpg') eg(""" Image("lj8100.jpg") """,after=0.1) disc("""will display as""") try: getStory().append(Image(I)) except: disc("""An image should have appeared here.""") disc("""whereas""") eg(""" im = Image("lj8100.jpg", width=2*inch, height=2*inch) im.hAlign = 'CENTER' """, after=0.1) disc('produces') try: im = Image(I, width=2*inch, height=2*inch) im.hAlign = 'CENTER' getStory().append(Image(I, width=2*inch, height=2*inch)) except: disc("""An image should have appeared here.""") heading2("""$Spacer(width, height)$""") disc("""This does exactly as would be expected; it adds a certain amount of space into the story. At present this only works for vertical space. """) CPage(1) heading2("""$PageBreak()$""") disc("""This $Flowable$ represents a page break. It works by effectively consuming all vertical space given to it. This is sufficient for a single $Frame$ document, but would only be a frame break for multiple frames so the $BaseDocTemplate$ mechanism detects $pageBreaks$ internally and handles them specially. """) CPage(1) heading2("""$CondPageBreak(height)$""") disc("""This $Flowable$ attempts to force a $Frame$ break if insufficient vertical space remains in the current $Frame$. It is thus probably wrongly named and should probably be renamed as $CondFrameBreak$. """) CPage(1) heading2("""$KeepTogether(flowables)$""") disc(""" This compound $Flowable$ takes a list of $Flowables$ and attempts to keep them in the same $Frame$. If the total height of the $Flowables$ in the list $flowables$ exceeds the current frame's available space then all the space is used and a frame break is forced. """)