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Publisherintermediate

Sub-Templates, Style Templates & Reusability

Explain how sub-templates and style templates promote reuse and consistency across many BI Publisher report layouts.

Fifty reports sharing a header means one logo change touching fifty templates — unless the shared parts are defined once.

It's like a company using a shared letterhead template for every department's correspondence instead of each department designing and hand-typing their own header from scratch — update the letterhead once, and every future letter from every department automatically uses the new version.

Key Concepts

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A sub-template is a reusable RTF fragment.
    <?import:xdoxsl:///Custom/common.xsb?>
    <?call:companyHeader?>
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The sub-template holds named blocks:
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    <?template:companyHeader?>
      ... logo, address, registration number ...
    <?end template?>
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    <?template:legalFooter?>
      ... disclaimer ...
    <?end template?>
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Change the address once and every report that calls it is correct.
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Sub-templates can hold logic, not just layout. A formatting routine — rendering an amount in words for a cheque, formatting an address block that varies by country — is defined once and called wherever needed.
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That is the more valuable use, because logic duplicated across fifty templates diverges in ways a logo cannot.
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A style template handles appearance rather than content. Fonts, sizes, colours, table borders and heading styles, applied across reports so they look like one organisation produced them.
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    sub-template   shared content and logic
    style template shared appearance
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Applying a style template to an existing report restyles it without touching its layout, which is what makes a rebrand feasible.
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Why this is asked. It is a maintainability question, and it separates someone who has built one report from someone who has maintained a hundred.
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The scenario is always the same: the legal disclaimer changes. With sub-templates it is one edit. Without, it is opening every template, and the ones that are missed are the ones that go out.
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The practical caution. A sub-template is a dependency. Changing it changes every report using it, including ones nobody has looked at for two years.
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So a sub-template change needs testing across its consumers, and knowing who those are means keeping track — which is the small cost that comes with the large saving.
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What the interviewer is probing.1. "What is the difference between a sub-template and a style template?" Probing: the distinction. Stalls: "Nothing." Moves up: a sub-template holds reusable content and logic; a style template holds shared formatting applied across reports.
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2. "What is the maintenance argument?" Probing: the value. Stalls: "Less typing." *Moves up:* a letterhead or disclaimer change is made once rather than in two hundred templates, which is the difference between an hour and a project.
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3. "How is a sub-template referenced?" Probing: the mechanics. Stalls: "By name." *Moves up:* imported by its catalog path and called by template name, so it must be deployed before the parent runs.
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4. "What is the deployment gotcha?" Probing: the practical angle. Stalls: "None." *Moves up:* the path is environment-specific, so a migration that moves folders breaks every report referencing it.
Use cases:sub-templatesreusabilitytemplate-maintenance