HTML Escaping

The Comprehensive Guide to HTML Escaping in Jinja n nnHTML escaping is a fundamental security practice for any web application that uses dynamic data. It involves converting special characters like <, >, &, “, and ‘ into their HTML-safe equivalents (e.g., < becomes &lt;). This prevents a common and dangerous vulnerability known as Cross-Site Scripting…

Line Statements

Line Statements in Jinja — Usage, Compatibility, and Limits nA concise guide to enabling and using line statements in Jinja, with environment notes (Python vs. Flutter) and clearly stated limits so teams can adopt the feature confidently.nn Jinja’s standard syntax uses {% … %} to define blocks and tags. For developers who prefer a more…

Jinja Expression Comparison: !=

Jinja2 Comparison Expression: != n nnThe != operator in Jinja2 is a comparison operator used to check if two objects are not equal. It is the logical inverse of the == operator and is a fundamental tool for controlling template logic. The operator returns true if the objects have different values and false if their…

Jinja Literal Expression: lists

Jinja Literal Expression: Lists n nnA list literal is a sequence of comma-separated values, enclosed in square brackets ([…]). Lists are useful for storing sequential data that you need to iterate over, such as a collection of items, user accounts, or navigation links. Lists are also mutable, meaning you can change their contents.nn nn How…

Jinja If: elif and else

Jinja elif and else Statements n n The Jinja2 elif and else statements are essential for creating templates that can handle multiple conditions. They extend the basic if statement to provide a clear, logical flow for different outcomes, much like in Python. nn n The elif Statement n The elif (short for “else if”) statement…

Jinja Imports: macros in a helper module

Jinja Macros in a Helper Module n n Jinja2’s macros are an excellent way to organize and reuse common pieces of code, especially for repetitive tasks like rendering form elements. By putting related macros into a dedicated helper module (a separate template file), you can keep your main templates clean and easy to read. This…

Jinja If: basic if statement

Jinja2 if Statement n n The Jinja2 if statement is a fundamental control structure for conditional logic in templates. It allows you to selectively render content based on whether a condition is true or false. In Jinja2, a variable is considered “truthy” if it’s defined and not empty. nn n Basic if Statement n The…

il8n Extension: translating strings in expressions

Translating Strings in Jinja Expressions n nnWhile the `trans` block is perfect for wrapping entire paragraphs and phrases for translation, what about single words or short phrases that are part of a larger expression? Jinja’s i18n extension provides a set of dedicated functions that allow you to translate strings directly within your template expressions. This…