Shape - OLE Object¶
An embedded Excel worksheet can appear as a shape on a slide. The shape itself is a graphics-frame, in which the worksheet “file” is embedded. The Excel binary appears as an additional part in the package. Other file types such as DOCX and PDF can also be embedded in a similar way.
Support for different file (object) types is OS dependent. For example, there is no support for embedded PPTX objects on MacOS although there is for Windows. Excel (XLSX) and Word (DOCX) are the two common denominators.
Proposed protocol¶
>>> from pptx.enum.shapes import PROG_ID
>>> shapes = prs.slides[0].shapes
>>> shape = shapes.add_ole_object(
"worksheet.xlsx", PROG_ID.EXCEL, left, top, width, height
)
>>> shape
<pptx.shapes.graphfrm.GraphicFrame instance at 0x00000008>
>>> shape.shape_type
MSO_SHAPE_TYPE.EMBEDDED_OLE_OBJECT
>>> ole_format = shape.ole_format
>>> ole_format
<pptx.shapes.graphfrm._OleFormat instance at 0x00000010>
>>> ole_format.blob
<bytes instance at 0x00000018>
>>> ole_format.prog_id
'Excel.Sheet.12'
>>> ole_format.show_as_icon
True
PowerPoint UI behaviors¶
Insert a blank object. PowerPoint allows a “new”, blank OLE object to be inserted by selecting the type. The available types appear to be determined by a set of “registered” OLE server applications.
This behavior seems quite bound to some user interaction to fill out the object and in any case is outside the abilities of python-pptx running on an arbitrary OS. This behavior will have no counterpart in python-pptx. Only the “insert-from-file” mode will be available in python-pptx.
Auto-detect `progId` from file. When the “insert-from-file” option is chosen, PowerPoint automatically detects the progId (str OLE server identifier, intuitively “file-type”) for the inserted file.
This would be a lot of work for python-pptx to accomplish and in the end would be partial at best. The base case would be that python-pptx requires progId to be specified by the caller. python-pptx will provide an Enum that provides ready access to common str progId cases like Excel Worksheet, Word Document, and PowerPoint Presentation. Other cases could be resolved by experimentation and inspecting the XML to determine the appropriate str progId value.
Show as preview. PowerPoint allows the option to show the embedded object as either a “preview” of the content or as an icon. The preview is an image (EMF for XLSX and perhaps other MS Office applications) and I expect it is provided by the OLE server application (Excel in the XLSX case) which renders to an image instead of rendering to the screen.
python-pptx has no access to an OLE server and therefore cannot request this image. Only the “display as icon” mode will be supported in python-pptx. For this reason, the python-pptx call will have no display_as_icon parameter and that “value” will always be True.
User-selectable and partially-generated icon. When “display-as-icon” is selected, PowerPoint generates a composite icon that combines a graphical icon and a caption. Together, these typically look like a file icon that appears on the user’s desktop, except the file-name portion is a generic file-type name like “Microsoft Excel Workbook”.
The icon portion can be replaced with an arbitrary icon selected by the user (Windows only). The icon can be selected from a .ico file or an icon library or from the resource area of an .exe file.
The resulting image in the PPTX package is a Windows Meta File (WMF/EMF), a vector format, perhaps to allow smooth scaling.
In the general case (i.e. non-Windows OS), python-pptx has neither the option of extracting icons from an arbitrary icon or resource library or
Link to file rather than embed. When inserting an object from a file, a user can choose to link the selected file rather than embed it. This option appears in the Windows version only.
The only difference in the slide XML is the appearance of a <p:link> element under <p:oleObj> rather than a <p:embed> element. In this case, the relationship referred to by r:id attribute of p:oleObj is an external link to the target file and no OLE object part is added to the PPTX package.
Auto-position and size. In the PowerPoint UI, the OLE object is inserted at a fixed size and in a default location. Afterward the shape can be repositioned and resized to suit. In the API, the position and size are specified in the call.
MS API Protocol¶
Shapes.AddOLEObject(
Left, Top, Width, Height,
ClassName,
FileName,
DisplayAsIcon,
IconFileName,
IconIndex,
IconLabel,
Link,
)
Left, Top, Width and Height specify the position and size of the graphic-frame object. They also specify the size of the icon image when display_as_icon is True and the size of the preview image when display_as_icon is False or omitted. These are all optional, and are determined by PowerPoint if not specified. I believe the shape is placed centered in the slide if the position is not specified and the size is determined by the icon or preview graphic if not specified.
PowerPoint updates these values in the icon-image element to track those of the graphic-frame shape when the user changes the size of the graphic-frame shape, but it seems to ignore these values when they don’t agree.
ClassName identifies the “file-type” or more precisely, the OLE server (program) used to “open” the embedded or linked file. This is used only when a new, empty object is being added because otherwise PowerPoint derives this from the file specified with FileName
This can be either the OLE long class name or the ProgID for the object that’s to be created, but a class-name ends up being converted to a ProgID. Either the ClassName or FileName argument for the object must be specified, but not both. ClassName triggers the “insert-newly-created-object” mode and FileName triggers “insert-existing-object” mode.
DisplayAsIcon (optional boolean) determines whether the OLE object will be displayed as an icon or as a “preview”. The default is False.
IconFileName allows the user to specify an icon file containing the icon to display when DisplayAsIcon is True. If not specified, a default icon for the OLE class is used. Note that this file can contain a collection of images, which is why the IconIndex parameter is available. These icon files are Windows specific and would not typically be found in other operating systems.
IconIndex specifies the index of the desired icon within IconFileName. The first icon in the file has the index number 0 (zero). If an icon with the given index number doesn’t exist in IconFileName, the icon with the index number 1 (the second icon in the file) is used. The default value is 0 (zero).
IconLabel is a str label (caption) to be displayed beneath the icon. By default, this is like “Microsoft Excel Worksheet”. This caption is integrated into the specified “display-as-icon” image.
Link is a boolean flag that determines whether the OLE object will be linked to the file from which it was created (rather than embedded). If you specified a value for ClassName, this argument must be msoFalse (linking is not an option in “insert-newly-created-object” mode).
Candiate protocol¶
SlideShapes.add_ole_object(
object_file,
prog_id,
left,
top,
width=None,
height=None,
icon=None,
link=False,
)
python-pptx only supports adding an OLE object in “display-as-icon” mode. It has no way of soliciting a preview image from an OLE server application, so that option is not practical for us.
object_file is the file containing the object to be inserted. It may be either a str path to the file or a (binary) file-like object (typically io.Bytes) containing the bytes of the file and implementing file-object semantics like .read() and .seek().
prog_id is a PROG_ID Enum member or str identifier like “Excel.Sheet.12” specifying the “type” of the object in terms of what application is used to “open” it. In Microsoft parlance, this identifies the OLE server called upon to operate on this object.
The pptx.enum.shapes.PROG_ID enumeration defines these values for common cases like an Excel workbook, an Word document, or another PowerPoint presentation. Probably we should also include PDFs and any other common cases we can think of.
A regular str value can be discovered by inspecting the XML of an example presentation and these will work just the same as a PROG_ID Enum value, allowing ready expansion to other OLE object types.
I expect that a file of any type could be included, even if it doesn’t have an OLE server application and it could then at least be accessed via python-pptx, although I don’t suppose it would do anything useful from the PowerPoint UI. In any case, I don’t believe it would raise an error and there wouldn’t be anything we could (or would probably want) to do to stop someone from doing that.
left and top are each an Emu object (or an int interpreted as Emu) and specify the position of the inserted-object shape.
width and height are optional Emu/int objects and together specify the size of the graphic-frame object. Their use is not required and perhaps even discouraged unless the defaults of 1.00” (914400 EMU) wide and .84” (771480 EMU) tall do not suit for some reason, perhaps because the provided icon image is a non-standard size. The default size is that when a user inserts an object displayed as an icon in the PowerPoint UI and I at least have been unable to make it look better by resizing it.
icon is an arbitrary image that appears in the graphic-frame object in lieu of the inserted object. It is optional, because a default icon is provided for each of the members of PROG_ID and this image need not be specified when prog_id is an instance of PROG_ID. Like an image object used in SlideShapes.add_picture(), this object can be either a str path or a file-like object (typically io.BytesIO) containing the image.
This parameter is technically optional, but is required when prog_id is not an member of PROG_ID (because in that case we have no default icon available). The caller can always specify a custom icon image, even when inserting an object type available in PROG_ID. In that case, the image provided is used instead of the default icon.
link is a boolean indicating the object should be linked rather than embedded. Linking probably only works in a Windows environment. This option may not be implemented in the initial release and this parameter will not appear in that case.
>>> shapes = slide.shapes
>>> embedded_xlsx_shape = shapes.AddOLEObject(left, top, width, height, file_name)
XML specimens¶
relationships:
<?xml version='1.0' encoding='UTF-8' standalone='yes'?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
<Relationship Id="x" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/image" Target="../media/image4.emf"/>
<Relationship Id="x" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/notesSlide" Target="../notesSlides/notesSlide1.xml"/>
<Relationship Id="x" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/package" Target="../embeddings/Microsoft_Excel_Worksheet.xlsx"/>
<Relationship Id="x" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/slideLayout" Target="../slideLayouts/slideLayout14.xml"/>
<Relationship Id="x" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/vmlDrawing" Target="../drawings/vmlDrawing1.vml"/>
</Relationships>
simple column chart:
<p:graphicFrame>
<p:nvGraphicFramePr>
<p:cNvPr id="2" name="Object 1">
<a:extLst>
<a:ext uri="{FF2B5EF4-FFF2-40B4-BE49-F238E27FC236}">
<a16:creationId xmlns:a16="http://schemas.microsoft.com/office/drawing/2014/main" id="{9DA7C2C3-4766-419F-9ED0-2856E43424DD}"/>
</a:ext>
</a:extLst>
</p:cNvPr>
<p:cNvGraphicFramePr>
<a:graphicFrameLocks noChangeAspect="1"/>
</p:cNvGraphicFramePr>
<p:nvPr>
<p:extLst>
<p:ext uri="{D42A27DB-BD31-4B8C-83A1-F6EECF244321}">
<p14:modId xmlns:p14="http://schemas.microsoft.com/office/powerpoint/2010/main" val="2099550745"/>
</p:ext>
</p:extLst>
</p:nvPr>
</p:nvGraphicFramePr>
<p:xfrm>
<a:off x="1792101" y="2202989"/>
<a:ext cx="659686" cy="1371600"/>
</p:xfrm>
<a:graphic>
<a:graphicData uri="http://schemas.openxmlformats.org/presentationml/2006/ole">
<mc:AlternateContent xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
<mc:Choice xmlns:v="urn:schemas-microsoft-com:vml" Requires="v">
<p:oleObj spid="_x0000_s1058" name="Worksheet" showAsIcon="1" r:id="rId4" imgW="381148" imgH="792690" progId="Excel.Sheet.12">
<p:embed/>
</p:oleObj>
</mc:Choice>
<mc:Fallback>
<p:oleObj name="Worksheet" showAsIcon="1" r:id="rId4" imgW="381148" imgH="792690" progId="Excel.Sheet.12">
<p:embed/>
<p:pic>
<p:nvPicPr>
<p:cNvPr id="0" name=""/>
<p:cNvPicPr/>
<p:nvPr/>
</p:nvPicPr>
<p:blipFill>
<a:blip r:embed="rId5"/>
<a:stretch>
<a:fillRect/>
</a:stretch>
</p:blipFill>
<p:spPr>
<a:xfrm>
<a:off x="1792101" y="2202989"/>
<a:ext cx="659686" cy="1371600"/>
</a:xfrm>
<a:prstGeom prst="rect">
<a:avLst/>
</a:prstGeom>
</p:spPr>
</p:pic>
</p:oleObj>
</mc:Fallback>
</mc:AlternateContent>
</a:graphicData>
</a:graphic>
</p:graphicFrame>