Placeholders in new slide¶

Topic of inquiry¶

What placeholder shapes are added to a new slide when it is added to a presentation?

Abstract¶

Slides were created based on a variety of slide layouts so their placeholder elements could be inspected to reveal slide construction behaviors that depend on the slide layout chosen. A placeholder shape appeared in each slide corresponding to each of the placeholder shapes in the slide layout, excepting those of footer, date, and slide number type. Placeholder shapes were <p:sp> elements for all placeholder types rather than matching the element type of the shape they hold a place for. Each slide-side placeholder had a <p:ph> element that exactly matched the corresponding element in the slide layout, with the exception that a hasCustomPrompt attribute, if present in the slide layout, did not appear in the slide. Placeholders in the slide were named and numbered differently. All placeholders in the slide layout had a <p:txBody> element, but only certain types had one in the slide. All placeholders were locked against grouping.

Procedure¶

This procedure was run using PowerPoint for Mac 2011 running on an Intel-based Mac Pro running Mountain Lion 10.8.2.

Create a new presentation based on the “White” theme.
Add a new slide layout and add placeholders of the following types. The new slide layout is (automatically) named Custom Layout.
- Chart
- Table
- SmartArt Graphic
- Media
- Clip Art
Add a new slide for each of the following layouts. Do not enter any content into the placeholders.
- Title Slide (added automatically on File > New)
- Title and Content
- Two Content
- Comparison
- Content with Caption
- Picture with Caption
- Vertical Title and Text
- Custom Layout
Save and unpack the presentation. This command works on OS X: unzip white.pptx -d white
Inspect the slide.xml files and compare placeholders with those present in their corresponding slideLayout.xml file.

Observations¶

Typical XML for a placeholder:

<p:sp>
  <p:nvSpPr>
    <p:cNvPr id="2" name="Title 1"/>
    <p:cNvSpPr>
      <a:spLocks noGrp="1"/>
    </p:cNvSpPr>
    <p:nvPr>
      <p:ph type="ctrTitle"/>
    </p:nvPr>
  </p:nvSpPr>
  <p:spPr/>
  <p:txBody>
    <a:bodyPr/>
    <a:lstStyle/>
    <a:p>
      <a:endParaRPr lang="en-US"/>
    </a:p>
  </p:txBody>
</p:sp>

elements¶

Placeholder shapes WERE created corresponding to layout placeholders of the following types in the slide layout:
- 'title'
- 'body'
- 'ctrTitle'
- 'subTitle'
- 'obj'
- 'chart'
- 'tbl'
- 'clipArt'
- 'dgm' (SmartArt Graphic, perhaps abbreviation of ‘diagram’)
- 'media'
- 'pic'
- None (type attribute default is 'obj')
Placeholder shapes WERE NOT created corresponding to layout placeholders of these types in the slide layout:
- 'dt' (date)
- 'sldNum' (slide number)
- 'ftr' (footer)
The following placeholder types do not apply to slides (they apply to notes pages and/or handouts).
- 'hdr'
- 'sldImg'
<p:txBody> element. Placeholder shapes of the following types had a <p:txBody> element. Placeholders of all other types did not have a <p:txBody> element.
- 'title'
- 'body'
- 'ctrTitle'
- 'subTitle'
- 'obj' (and those without a type attribute)
<p:cNvPr> element. Each placeholder shape in each slide had a <p:cNvPr> element (it is a required element) populated with id and name attributes.
- The value of the id attribute of p:cNvPr does not correspond to its value in the slide layout. Shape ids were renumbered starting from 2 and proceeding in sequence (e.g. 2, 3, 4, 5, …). Note that id=”1” belongs to the spTree element, at /p:sld/p:cSld/p:spTree/p:nvGrpSpPr/p:cNvPr@id.
- The value of the name attribute is of the form ‘%s %d’ % (type_name, num), where type_name is determined by the placeholder type (e.g. ‘Media Placeholder’) and num appears to default to id - 1. The assigned name in each case was similar to its counterpart in the slide layout (same type_name), but its number was generally different.
<p:cNvSpPr> element. Placeholder shapes of all types had the element <a:spLocks noGrp="1"/> specifying the placeholder could not be grouped with any other shapes.
<p:spPr> element. All placeholder shapes had an empty <p:spPr> element.

attributes¶

type. The type attribute of the <p:ph> element was copied without change. Where no type attribute appeared (defaults to “obj”, indicating a “content” placeholder), no type attribute was added to the <p:ph> element.
orient. The orient attribute of the <p:ph> element was copied without change. Where no orient attribute appeared (defaults to “horz”), no orient attribute was added to the <p:ph> element.
sz. The sz (size) attribute of the <p:ph> element was copied without change. Where no sz attribute appeared (defaults to “full”), no sz attribute was added to the <p:ph> element.
idx. The idx attribute of the <p:ph> element was copied without change. Where no idx attribute appeared (defaults to “0”, indicating the singleton title placeholder), no idx attribute was added to the <p:ph> element.
hasCustomPrompt. The hasCustomPrompt attribute of the <p:ph> element was NOT copied from the slide layout to the slide.

Other observations¶

Placeholders created from the slide layout were always <p:sp> elements, even when they were a placeholder for a shape of another type, e.g. <p:graphicFrame>. When the on-screen placeholder for a table was clicked to add a table, the <p:sp element was replaced by a <p:graphicFrame> element containing the table. The <p:ph> element was retained in the new shape. Reapplying the layout to the slide caused the table to move to the original location of the placeholder (the idx may have been used for matching). Deleting the table caused the original placeholder to reappear in its original position.

Conclusions¶

Placeholder shapes are added to new slides based on the placeholders present in the slide layout specified on slide creation.
Placeholders for footer, slide number, and date are excluded.
Each new placeholder is assigned an id starting from 2 and proceeding in increments of 1 (e.g. 2, 3, 4, …).
Each new placeholder is named based on its type and the id assigned.
Placeholders are locked against grouping.
Placeholders of selected types get a minimal <p:txBody> element.
Slide placeholders receive an exact copy of the <p:ph> element in the corresponding slide layout placeholder, except that the optional hasCustomPrompt attribute, if present, is not copied.

Open Questions¶

None.