Add Conditional Content with If/Else Leave feedback

Overview

Conditional blocks allow you to display different content in your documents based on data values. GroupDocs.Assembly for .NET supports if/elseif/else syntax similar to C#, 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 C# expressions that return boolean values
Provide content for each condition branch
Assemble the document with your data

Note
Conditional expressions must return boolean values. You can use comparison operators (==, !=, <, >, <=, >=), logical operators (&&, ||, !), and method calls that return bool.

Simple If/Else Block

Display content based on a simple condition:

using GroupDocs.Assembly;

public class Customer
{
    public string Name { get; set; }
    public decimal Balance { get; set; }
}

public static void SimpleConditional()
{
    var customer = new Customer
    {
        Name = "John Doe",
        Balance = 1500.00m
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(customer, "customer"));
    
    Console.WriteLine("Conditional content generated successfully.");
}

Template Example for Simple If/Else

In your template (ConditionalTemplate.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>>

If/Elseif/Else Block

Use multiple conditions with elseif:

using GroupDocs.Assembly;

public class Order
{
    public decimal Amount { get; set; }
}

public static void MultipleConditions()
{
    var order = new Order
    {
        Amount = 750.00m
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(order, "order"));
    
    Console.WriteLine("Multiple conditions processed successfully.");
}

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>>

Conditional Content with Collections

Check if collections have items:

using GroupDocs.Assembly;
using System.Collections.Generic;

public class Report
{
    public List<string> Items { get; set; }
}

public static void ConditionalWithCollections()
{
    var report = new Report
    {
        Items = new List<string> { "Item 1", "Item 2", "Item 3" }
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(report, "report"));
    
    Console.WriteLine("Conditional content with collections generated successfully.");
}

Template:

<<if [report.Items.Any()]>>
Items:
<<foreach [in report.Items]>>
- <<[report.Items_Text]>>
<</foreach>>
<<else>>
No items available.
<<if>>

Conditional Content in Data Bands

Use conditional blocks within foreach loops:

using GroupDocs.Assembly;
using System.Collections.Generic;

public class Product
{
    public string Name { get; set; }
    public decimal Price { get; set; }
    public bool InStock { get; set; }
}

public static void ConditionalInDataBand()
{
    List<Product> products = new List<Product>
    {
        new Product { Name = "Laptop", Price = 999.99m, InStock = true },
        new Product { Name = "Mouse", Price = 29.99m, InStock = false },
        new Product { Name = "Keyboard", Price = 79.99m, InStock = true }
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(products, "products"));
    
    Console.WriteLine("Conditional content in data band generated successfully.");
}

Template:

<<foreach [in products]>>
<<[Name]>> - <<[Price]:"C">>
<<if [InStock]>>
✓ In Stock
<<else>>
✗ Out of Stock
<<if>>

<</foreach>>

Complex Conditions

Use logical operators for complex conditions:

using GroupDocs.Assembly;

public class Employee
{
    public int YearsOfService { get; set; }
    public decimal Salary { get; set; }
    public string Department { get; set; }
}

public static void ComplexConditions()
{
    var employee = new Employee
    {
        YearsOfService = 5,
        Salary = 75000m,
        Department = "Engineering"
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(employee, "employee"));
    
    Console.WriteLine("Complex conditions processed successfully.");
}

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>>

Conditional Formatting

Apply different formatting based on conditions:

using GroupDocs.Assembly;

public class Invoice
{
    public decimal Amount { get; set; }
    public bool IsPaid { get; set; }
}

public static void ConditionalFormatting()
{
    var invoice = new Invoice
    {
        Amount = 1500.00m,
        IsPaid = false
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(invoice, "invoice"));
    
    Console.WriteLine("Conditional formatting applied successfully.");
}

Template:

Amount: <<[invoice.Amount]:"C">>

<<if [invoice.IsPaid]>>
Status: PAID
<<else>>
Status: UNPAID - Payment Required
<<if>>

Using Methods in Conditions

Call methods that return boolean values:

using GroupDocs.Assembly;
using System.Collections.Generic;

public class Order
{
    public List<OrderItem> Items { get; set; }
    
    public bool HasItems()
    {
        return Items != null && Items.Count > 0;
    }
}

public class OrderItem
{
    public string Name { get; set; }
}

public static void ConditionalWithMethods()
{
    var order = new Order
    {
        Items = new List<OrderItem> { new OrderItem { Name = "Product" } }
    };
    
    DocumentAssembler assembler = new DocumentAssembler();
    assembler.AssembleDocument("ConditionalTemplate.docx", "ConditionalOutput.docx", 
        new DataSourceInfo(order, "order"));
    
    Console.WriteLine("Conditional with methods processed successfully.");
}

Template:

<<if [order.HasItems()]>>
Order contains items.
<<else>>
Order is empty.
<<if>>

Warning
Conditional blocks must be properly closed with <<if>>. Nested conditional blocks are supported, but ensure proper nesting and closing of all blocks.

Advanced Usage Topics

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.

More resources

GitHub Examples

You may easily run the code above and see the feature in action in our GitHub examples:

Free Online Apps

Along with the full-featured .NET 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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Add Conditional Content with If/Else Leave feedback

Overview

Simple If/Else Block

Template Example for Simple If/Else

If/Elseif/Else Block

Conditional Content with Collections

Conditional Content in Data Bands

Complex Conditions

Conditional Formatting

Using Methods in Conditions

Advanced Usage Topics

More resources

GitHub Examples

Free Online Apps

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