Text Substitution

In Xano, variable text substitution allows you to dynamically replace parts of text with values from inputs, variables, or other sources. This feature is incredibly useful for creating dynamic content, personalizing messages, and building flexible APIs. In this guide, we'll explore three powerful methods for variable text substitution: Sprintf, Replace, and RegexReplace.

Sprintf: Substituting Text and Numeric Values

The `Sprintf` filter is a versatile tool for replacing placeholders in text with variable values. It uses the following placeholders:

• `%s` for substituting text values
• `%d` for enforcing numeric values

Here's how to use `Sprintf`:

1. Create a text variable or input field containing placeholders (e.g., `%s jumped over %s`).
2. Add the `Sprintf` filter to the variable.
3. Define the arguments (variables or inputs) to replace the placeholders in the order they appear.

For example, let's say you have two inputs: `thing1` and `thing2`. You can create a variable with the text `%s jumped over %s` and apply the `Sprintf` filter with `thing1` and `thing2` as arguments. If `thing1` is "the cat" and `thing2` is "the moon", the result will be "the cat jumped over the moon".

The `%d` placeholder is useful when you need to enforce a numeric value substitution. Simply replace `%s` with `%d` in the text, and provide a numeric argument in the corresponding position.

Sprintf is particularly handy for constructing dynamic headers (e.g., `Authorization: Bearer %s`) or building URLs with variable parameters.

Replace: Substituting Fixed Phrases

The `Replace` filter is ideal when you need to replace a fixed phrase or word with another value throughout a text. It takes two arguments:

1. The search phrase to be replaced
2. The replacement value

Here's how to use the `Replace` filter:

1. Create a text variable or input field containing the phrase you want to replace (e.g., "name enjoys warm weather").
2. Add the `Replace` filter to the variable.
3. In the "Search" field, enter the phrase you want to replace (e.g., "name").
4. In the "Replace" field, enter the value you want to substitute (e.g., an input variable like `thing1`).

For instance, if you have a text variable containing "name enjoys warm weather and beachy vibes when name isn't at the beach, name enjoys relaxing by enjoying a movie", you can replace all instances of "name" with an input value (e.g., "Jordan") using the `Replace` filter.

The `Replace` filter is particularly useful when you need to consistently substitute a fixed phrase with dynamic values throughout a text.

RegexReplace: Substituting with Regular Expressions

The `RegexReplace` filter is a powerful tool for finding and replacing text patterns using regular expressions. It takes two arguments:

1. The regular expression pattern to search for
2. The replacement value

Here's how to use the `RegexReplace` filter:

1. Create a text variable or input field containing the text you want to modify.
2. Add the `RegexReplace` filter to a new variable.
3. In the "Subject" field, enter the variable containing the original text.
4. In the "Value" field, enter the regular expression pattern you want to search for.
5. In the "Replace" field, enter the value you want to substitute for the matched patterns.

For example, let's say you have a variable containing "Jordan enjoys warm weather and beachy vibes when Jordan isn't at the beach, Jordan enjoys relaxing by enjoying a movie". You can use the `RegexReplace` filter to replace all instances of "Jordan" with "Michael" by setting the "Value" field to `Jordan` and the "Replace" field to `Michael`.

The `RegexReplace` filter is incredibly powerful, allowing you to search for and replace complex patterns based on regular expressions. However, it does require some familiarity with regular expression syntax.

By mastering these three methods for variable text substitution in Xano, you'll be able to create dynamic, personalized content and build flexible APIs tailored to your specific needs. Whether you're substituting fixed phrases, enforcing numeric values, or searching for complex patterns, Xano's variable text substitution capabilities empower you to build robust and adaptable applications without writing a single line of code.