Inserting Documents Dynamically

You can insert contents of outer documents to your reports dynamically using doc tags. A doc tag denotes a placeholder within a template for a document to be inserted during runtime.

Syntax of a doc tag is defined as follows.

<<doc [document_expression]>>

Note – A doc tag can be used almost anywhere in a template document except textboxes and charts.

An expression declared within a doc tag is used by the engine to load a document to be inserted during runtime. The expression must return a value of one of the following types:

• A byte array containing document data
• An InputStream instance able to read document data
• An instance of the Document class
• A string containing a document URI, path, or Base64-encoded document data

While building a report, an expression declared within a doc tag is evaluated and its result is used to load a document which content replaces the doc tag then.

Note – If an expression declared within a doc tag returns a stream object, then the stream is closed by the engine as soon as a corresponding document is loaded.

By default, while inserting content of an outer document, the engine applies corresponding styles of a template document. This makes content of a result document look more consistent. However, you can keep source formatting for content being inserted by using a sourceStyles switch as shown in the following snippet.

<<doc [document_expression] -sourceStyles>>

The engine exhibits similar behavior when dealing with list numbering. By default, numbered lists from a template document are continued when their identifiers match those from a document being inserted. However, if numbering for content being inserted should be separated and kept as is, this can be done by applying a sourceNumbering switch as follows.

<<doc [document_expression] -sourceNumbering>>

Also, you can trim the last paragraph break from a document being inserted by using an inline switch. In particular, this feature is useful for a single-paragraph document being inserted, when it is necessary to put the document’s content within the same paragraph that contains a corresponding doc tag in order to apply the paragraph’s formatting such as list numbering. The following snippet shows the template syntax for this.

<<doc [document_expression] -inline>>

By default, a document being inserted is not checked against template syntax and is not populated with data. However, you can enable this by using a build switch as follows.

<<doc [document_expression] -build>>

When a build switch is used, the engine treats a document being inserted as a template that can access the following data available at the scope of a corresponding doc tag:

• Data sources
• Variables
• A contextual object (see “Using Contextual Object Member Access” for more information)
• Known external types (see “Setting up Known External Types” for more information)

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FAQ

1. Q: How do I insert a document from a file path using a doc tag?
   A: Place a doc tag in the template and provide the file path as a string expression, e.g. <<doc ["C:/Docs/Appendix.docx"]>>. At runtime the engine loads the file and replaces the tag with its content.

2. Q: I want the inserted document to keep its original formatting. Which switch should I use?
   A: Add the -sourceStyles switch to the tag: <<doc [docExpression] -sourceStyles>>. This tells the engine to preserve the source document’s styles instead of mapping them to the template’s styles.

3. Q: My inserted document contains numbered lists, but the numbering continues from the template list. How can I keep the numbering separate?
   A: Use the -sourceNumbering switch: <<doc [docExpression] -sourceNumbering>>. This prevents the engine from merging list identifiers and retains the original numbering of the inserted document.

4. Q: Can I insert a single‑paragraph document inline so that it adopts the surrounding paragraph’s formatting?
   A: Yes. Apply the -inline switch: <<doc [docExpression] -inline>>. The engine removes the trailing paragraph break of the inserted document and places its text inside the same paragraph that contains the tag.

5. Q: How can I populate merge fields inside the inserted document with data from my report?
   A: Add the -build switch: <<doc [docExpression] -build>>. The inserted document is treated as a template and can use the same data sources, variables, and contextual objects that are available at the location of the doc tag.