Creating reports in .NET and Java
C# Java HTML Other
Switch branches/tags
Nothing to show
Latest commit e7a687a Apr 8, 2017 @zapov zapov Templater v2.6.0
Advanced Java example which uses new sheet rename feature
Failed to load latest commit information.

Reporting for JVM and .NET

Templater is small reporting library with a minimal API.

These examples show various usages of the library.

Additional documentation is available from the official webpage.

How Templater works

Templater works by analyzing provided docx/xlsx document for tags. Tags are snippets of text written in either [[tag]] or {{tag}} format. Tags can have metadata which can be used for various customization purposes, such as formatting.

When tags are placed in resizable part of the document Templater can repeat that part of the document when collection is provided as input. An example of this is a row in a table, list, page, sheet or entire document.

Templater doesn't have it's own editor, but rather uses documents prepaired in Word/Excel/some other editor. While this works great in most cases, this means Templater must infer intention from the structure of the document/tags, which doesn't contain any Templater specific extension.

Templater has minimal API for interaction:

  • high level process method
  • low level replace, resize and clone

Usage of Templater mostly consists from passing existing model to high level API.

Data types

Most data types are processed by Templater with conversion to string. In Excel some types are converted into native Excel formats, such as numbers and dates.

Collections are usually processed by duplicating context which encapsulates all tags matching that collection.

Templater will use reflection to analyze classes, but it can work also on dynamic data types such as dictionary.

Templater has special behavior for several data types, such as:

  • image - injects image into the document
  • nested array/DataTable - invokes dynamic resize feature of the Templater
  • XML - can inject XML into Word as-is

and several others (DateTime, multiline strings, ...).


Low level resize(tags, count) API is used for duplicating part of the document. It can work for simple cases, such as single row in a table, but can be used for more complex ones:

  • multiple rows - tags can span multiple rows, which will cause multi-row copying
  • nested elements - tags can span multiple tables/lists which can be used for cloning complex document layouts
  • formula rewriting - as formulas are moved around and copied, their expressions will be adjusted accordingly
  • row/column styles - if possible styles will be maintained during horizontal or vertical resizing (horizontal resizing requires horizontal-resize metadata)
  • pushdown/pushright - elements bellow/right of tags area will be moved according to builtin rules
  • merge cells/named ranges/tables influence push rules by extending the affected region


Templater has several extensibility points. Various plugins are embedded into library, while others can be registered during library initialization.


Q: How can I inject text with special color/bolding instead of plain (or pre-formatted) text into Templater?
A: You need to use XML to inject rich text into document (and format it appropriatelly to the target document format).

Q: Documents created with Templater are reported as corrupted. What does that mean and how to fix it?
A: Corrupted document usually means that resulting document does not abide to the specification. This can be for various of reasons. Sometimes it's due to faulty input (eg Word does not support all characters ... so you need to handle what to do about special characters such as unicode 26 using low level API plugin). Sometimes it's due to bugs/missing features in Templater in which case you should report it back so we can fix the bug.

Q: Can I convert docx/xlsx to PDF?
A: Templater does not support converting documents to PDF. If MS Office can't be used to do PDF conversion next best thing (which supports most features) is to set up headless LibreOffice and do PDF conversion via it. Almost all non MS solution have some pixel perfect issues :(

Q: Is this just a fancy mail-merge library?
A: Not at all. Templater can create really complex documents, but you might need to have good knowledge of Word/Excel to create such complex documents.