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Javascript Execution Command

This type of command allows us to execute JavaScript code.

With a JavaScript Execution command, we can pretty much do everything that JavaScript allows us to do. Some examples are given below.

We can still access the tp object and all the internal variables / functions from this type of command.


JavaScript Execution commands let you access global namespace variables. This means you can access things like app or moment.


Some internal functions are asynchronous. When calling such functions inside a JavaScript execution command, don't forget to use the await keyword if necessary.

How to output a value from a JavaScript Execution Command ?#

Sometimes, you may want to output something when using a JS execution command. This is possible although a raw display / interpolation command is preferable.

When the Eta templating engine generates a replacement string using all of our commands results, it is stored in a variable named tR. This is the string that will contain the processed file content. You are allowed to access that variable from a JS execution command.

This means that, to output something from a JS execution command, you just need to append what you want to output to that tR string variable.

For example, the following command: <%* tR += "test" %> will output test.


Here are some examples of things you can do using JavaScript Execution Commands:

<%* if (tp.file.title.startsWith("Hello")) { %>
This is a hello file !
<%* } else { %>
This is a normal file !
<%* } %>
<%* if (tp.frontmatter.type === "seedling") { %>
This is a seedling file !
<%* } else { %>
This is a normal file !
<%* } %>
<%* if (tp.file.tags.contains("#todo")) { %>
This is a todo file !
<%* } else { %>
This is a finished file !
<%* } %>
function log(msg) {
<%* log("Title: " + tp.file.title) %>
<%* tR += tp.file.content.replace(/stuff/, "things"); %>