Passing Data from Flask to JavaScript in Templates

Your application utilizes an API to retrieve data that is stored in a dictionary. Your goal is to pass specific information, namely the longitude and latitude coordinates, from this dictionary to JavaScript within the view. To understand how this can be achieved, it is essential to comprehend Flask's process of passing variables to templates.

Flask utilizes the render_template function to send variables to a template that is rendered in a browser. Using the Jinja2 template engine, these variables can be accessed and displayed within the HTML markup.

To make the variable available to JavaScript, you can utilize Jinja2's ability to embed Python expressions directly into your templates. Simply enclose the variable name within double curly braces ({{ variable_name }}). For instance, you can pass the geocode to JavaScript using the following code snippet:

This code snippet assigns the value of geocode[1] to the JavaScript variable myGeocode. Note that you can access any variable passed to the template using this syntax, regardless of its position within the HTML document.

For more complex data structures like lists, you can utilize the join() function to construct a comma-separated string and pass it as an array to JavaScript. Here's an example: