Removing Paragraphs Containing Only Template Syntax Tags

What is this page about?

This page explains how to remove paragraphs that contain only template syntax tags during document generation.

While building a report, some paragraphs containing only template syntax tags can become empty after the tags are removed or replaced with empty values. To remove such paragraphs from the report, you can apply the ReportBuildOptions.RemoveEmptyParagraphs option as shown in the following example.

ReportingEngine engine = new ReportingEngine();
engine.Options | = ReportBuildOptions.RemoveEmptyParagraphs;
engine.BuildReport(...);

The difference in the engine’s behavior when the option is applied and not applied is illustrated by the following examples.

Example 1

Template document

Prefix
<<[""]>>
Suffix

Result document without ReportBuildOptions.RemoveEmptyParagraphs applied

Prefix

Suffix

Result document with ReportBuildOptions.RemoveEmptyParagraphs applied

Prefix
Suffix

Example 2

Template document

Prefix
<<if [false]>>
Text to be removed
<</if>>
Suffix

Result document without ReportBuildOptions.RemoveEmptyParagraphs applied

Prefix

Suffix

Result document with ReportBuildOptions.RemoveEmptyParagraphs applied

Prefix
Suffix

Example 3

Note – In this example, persons is assumed to be a data table having a field Name.

Template document

Prefix
<<foreach [in persons]>>
<<[Name]>>
<</foreach>>
Suffix

Result document without ReportBuildOptions.RemoveEmptyParagraphs applied

Prefix

John Doe

Jane Doe

John Smith

Suffix

Result document with ReportBuildOptions.RemoveEmptyParagraphs applied

Prefix
John Doe
Jane Doe
John Smith
Suffix

The same functionality can be applied to selective paragraphs only. To achieve this, you can prepend names of corresponding tags with exclamation marks as shown in the following template snippet instead of applying of the ReportBuildOptions.RemoveEmptyParagraphs option.

<<![...]>>
<<!doc [...]>>
<<!foreach [...]>>...<</foreach>>
<<!if [...]>>...<<elseif [...]>>...<<else>>...<</if>>

For a tag with its name prepended with an exclamation mark, the engine treats a corresponding paragraph or paragraphs as if ReportBuildOptions.RemoveEmptyParagraphs was applied. For the rest of tags, the engine behaves as if ReportBuildOptions.RemoveEmptyParagraphs was not applied.

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FAQ

1. Q: How do I enable automatic removal of empty paragraphs that contain only template tags?
   A: Set the ReportBuildOptions.RemoveEmptyParagraphs flag on the ReportingEngine.Options property before building the report. Example:

   ReportingEngine engine = new ReportingEngine();
   engine.Options |= ReportBuildOptions.RemoveEmptyParagraphs;
   engine.BuildReport(...);
   

2. Q: Can I apply the empty‑paragraph removal to only specific tags instead of the whole document?
   A: Yes. Prefix the tag name with an exclamation mark (!) in the template. The engine will treat paragraphs containing those tags as empty and remove them, while leaving other tags unaffected. Example: <<!foreach [in persons]>>.

3. Q: Why does a paragraph remain after I enabled RemoveEmptyParagraphs?
   A: The paragraph may contain invisible characters such as spaces, tabs, or line‑breaks besides the tag. The option removes a paragraph only when it consists solely of the tag (or tag with an exclamation mark). Remove any extra whitespace from the template to allow the paragraph to be deleted.

4. Q: Can ReportBuildOptions.RemoveEmptyParagraphs be combined with other ReportBuildOptions?
   A: Absolutely. Use the bitwise OR operator to combine multiple options, e.g.,

   engine.Options |= ReportBuildOptions.RemoveEmptyParagraphs | ReportBuildOptions.PreserveFormFields;
   

5. Q: Does the empty‑paragraph removal affect tables or other container elements?
   A: The option works at the paragraph level. If a table cell contains only a tag that becomes empty, the entire paragraph (and thus the cell content) is removed, which may collapse the row if it becomes empty. It does not delete the table structure itself.