Add Conditional Content with If/Else Leave feedback
Conditional blocks allow you to display different content in your documents based on data values. GroupDocs.Assembly for Python via .NET supports if/elseif/else syntax, enabling you to create dynamic documents that adapt their content based on conditions.
The main syntax elements are:
<<if [condition]>>- display content if condition is true<<elseif [condition]>>- display content if previous conditions are false and this condition is true<<else>>- display content if all conditions are false<</if>>- closing tag
Here are the steps to use conditional content:
- Create a template with conditional blocks
- Define conditions using expressions that return boolean values
- Provide content for each condition branch
- Assemble the document with your data
NoteConditional expressions must return boolean values. The template writes them with C# operators, also when Python calls the assembler: comparison operators (==, !=, <, >, <=, >=), logical operators (&&, ||, !), and method calls that return bool. A Pythonboolin the data is a boolean in the template.
Display content based on a simple condition:
from decimal import Decimal
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
customer = {
"Name": "Quayside Bistro",
"Balance": Decimal("1500.00"),
}
assembler = DocumentAssembler()
assembler.assemble_document("customer-status.docx", "customer-status-report.docx",
DataSourceInfo(customer, "customer"))
print("Conditional content generated successfully.")
The following sample file is used in this example: customer-status.docx
Binary file (DOCX, 7 KB)
In your template (customer-status.docx):
Customer: <<[customer.Name]>>
<<if [customer.Balance > 1000]>>
Status: Premium Customer
You have a high balance and qualify for special benefits.
<<else>>
Status: Standard Customer
Thank you for your business.
<</if>>
Use multiple conditions with elseif:
from decimal import Decimal
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
order = {"Amount": Decimal("750.00")}
assembler = DocumentAssembler()
assembler.assemble_document("order-discount.docx", "order-discount-report.docx",
DataSourceInfo(order, "order"))
print("Multiple conditions processed successfully.")
The following sample file is used in this example: order-discount.docx
Binary file (DOCX, 7 KB)
Template with elseif:
Order Amount: <<[order.Amount]:"C">>
<<if [order.Amount > 1000]>>
Discount: 10% (Large order discount)
<<elseif [order.Amount > 500]>>
Discount: 5% (Medium order discount)
<<else>>
Discount: No discount available
<</if>>
Check if collections have items. A Python list reaches the template as a .NET collection, so it has the LINQ methods Any(), Count() and the others:
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
report = {
"Items": ["Harbor Blend whole bean coffee", "Aged harbour cheddar", "Cold-pressed olive oil"],
}
assembler = DocumentAssembler()
assembler.assemble_document("report-items.docx", "report-items-report.docx",
DataSourceInfo(report, "report"))
print("Conditional content with collections generated successfully.")
The following sample file is used in this example: report-items.docx
Binary file (DOCX, 7 KB)
Template:
<<if [report.Items.Any()]>>
Items:
<<foreach [item in report.Items]>>- <<[item]>>
<</foreach>><<else>>
No items available.
<</if>>
The items are strings, so the data band names its iteration variable (item) and outputs it with <<[item]>>. The band opens in the item’s paragraph and closes at the start of the next one, so it repeats one paragraph per item; a <<foreach>> tag on a line of its own would repeat an empty paragraph too.
Use conditional blocks within foreach loops:
from decimal import Decimal
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
products = [
{"Name": "Harbor Blend whole bean coffee", "Price": Decimal("18.40"), "InStock": True},
{"Name": "Lighthouse Espresso beans", "Price": Decimal("21.75"), "InStock": False},
{"Name": "Chestnut honey", "Price": Decimal("7.80"), "InStock": True},
]
assembler = DocumentAssembler()
assembler.assemble_document("product-stock-status.docx", "product-stock-status-report.docx",
DataSourceInfo(products, "products"))
print("Conditional content in data band generated successfully.")
The following sample file is used in this example: product-stock-status.docx
Binary file (DOCX, 7 KB)
Template:
<<foreach [in products]>><<[Name]>> - <<[Price]:"C">>
<<if [InStock]>>✓ In Stock<<else>>✗ Out of Stock<</if>>
<</foreach>>
Each product gives three paragraphs: its name and price, its stock status, and an empty line.
Use logical operators for complex conditions:
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
employee = {
"Name": "Amara Osei",
"YearsOfService": 5,
"Salary": 75000,
"Department": "Engineering",
}
assembler = DocumentAssembler()
assembler.assemble_document("employee-review.docx", "employee-review-report.docx",
DataSourceInfo(employee, "employee"))
print("Complex conditions processed successfully.")
The following sample file is used in this example: employee-review.docx
Binary file (DOCX, 7 KB)
Template with complex conditions:
<<if [employee.YearsOfService >= 5 && employee.Salary > 70000]>>
Eligible for promotion
<<elseif [employee.Department == "Engineering"]>>
Consider for technical leadership
<<else>>
Standard review process
<</if>>
Apply different formatting based on conditions:
from decimal import Decimal
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
invoice = {
"Amount": Decimal("1500.00"),
"IsPaid": False,
}
assembler = DocumentAssembler()
assembler.assemble_document("invoice-payment-status.docx", "invoice-payment-status-report.docx",
DataSourceInfo(invoice, "invoice"))
print("Conditional formatting applied successfully.")
The following sample file is used in this example: invoice-payment-status.docx
Binary file (DOCX, 7 KB)
Template:
Amount: <<[invoice.Amount]:"C">>
<<if [invoice.IsPaid]>>
Status: PAID
<<else>>
Status: UNPAID - Payment Required
<</if>>
A condition can call any method of a value that returns bool, such as Items.Any() or Name.StartsWith("Q"). A Python dict carries data, not methods, so a test that a .NET class would write as its own method (order.HasItems()) is computed in Python and passed as a key:
from groupdocs.assembly import DataSourceInfo, DocumentAssembler
items = [{"Name": "Smoked sea salt"}]
order = {
"Items": items,
"HasItems": len(items) > 0,
}
assembler = DocumentAssembler()
assembler.assemble_document("order-contents.docx", "order-contents-report.docx",
DataSourceInfo(order, "order"))
print("Conditional with methods processed successfully.")
The following sample file is used in this example: order-contents.docx
Binary file (DOCX, 7 KB)
Template:
<<if [order.HasItems]>>
Order contains items.
<<else>>
Order is empty.
<</if>>
WarningConditional blocks must be properly closed with<</if>>. Nested conditional blocks are supported, but ensure proper nesting and closing of all blocks. A block closed with<<if>>instead fails with “Tag ‘if’ is not well-formed. Tag end is unexpected.”
To learn more about table-row conditional blocks, conditional formatting in different document types, and advanced conditional scenarios, please refer to the advanced usage section.
You may easily run the code above and see the feature in action in our GitHub examples:
- GroupDocs.Assembly for .NET examples, plugins, and showcase
- GroupDocs.Assembly for Java examples, plugins, and showcase
- GroupDocs.Assembly for Python via .NET examples, plugins, and showcase
Along with the full-featured library, we provide simple but powerful free online apps.
To assemble documents from templates and data sources, you can use the online apps from the GroupDocs.Assembly App Product Family.
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