Home/ Questions/Q 8605761
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-12T02:55:10+00:00

This seems like a very basic problem but I can’t figure it out. I’m

  • 0

This seems like a very basic problem but I can’t figure it out. I’m passing a list of URLs into an HTML page and trying to print each one out in an href tag. I’m using Flask to run the test server, and can confirm that the variables are being passed in correctly (I can print out the entire list or elements from it).

My app route:

import doaudit # separate Py script that gets these urls

@app.route('/audit', methods = ['GET'])
def audit():
    return render_template('audit.html', listOfUrls = doaudit.listOfUrls)

My template:

<html>
    <head>
        <title>Data Audit</title>   
</head>
<body>

        {% for url in listOfUrls %}        
        <script language="JavaScript">
            document.write( "<a href=\"" + url + "\">linktext</a>" );
        </script>
        {% endfor %}

    </body>
</html>

I’ve tried variations on:

document.write( "<a href=\"" + '{{ listOfUrls[i] }}' + "\">linktext</a>" );

and iterating over all the i’s but that doesn’t work either.

The length of the list can vary, so I need an iterative solution. Thanks in advance.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    This is what you want:

    {% for url in listOfUrls %}        
    <script language="JavaScript">
        document.write( "<a href=\"" + {{ url|tojson|safe }} + "\">linktext</a>" );
    </script>
{% endfor %}

    The {{ url }} part tells Jinja2 (the template engine) that this url is actually the variable that you called so in the for url in blabla. Without it, it’s printed as is. You can see it when viewing the source in your browser. This means it will be interpreted as a JS variable, which will be undefined, equivalent to an empty string, which you then see.

    EDIT: added the tojson|safe calls, to make sure it will not break the JS code. You could do it this way : <a href=\"{{ url }}\">linktext</a>. But then a " would break your html/js code.

    EDIT 2: what the tojson filter does, is make it suitable to be put inside JS code. and the safe filter tells the rendering engine that it should not treat it as any text (which should be escaped to show properly in HTML), but treat it as safe text (HTML or not).

    • 0