Jinja2 template not rendering if-elif-else statement properly

Matty picture Matty · Feb 25, 2014 · Viewed 204.3k times · Source

I am trying to set the text color using css in a jinja2 template. In the following code I want to set the output string to print in a specific font color if the variable contains a string. Everytime the template is generated though it prints in red due to the else statement, it never see the first two conditions even though the output should be matched, I can tell what the output from the variable is when the table generates and it is as expected. I know my css is correct due to the printing of the string in red by default.

My first thought was to enclose the string I was checking for in quotes but that didn't work. Next was that jinja was not expanding RepoOutput[RepoName.index(repo)] but the for loop above it works, RepoName is expanded upon properly. I know if I add the braces it will print the variable which I am fairly certain will either break the template or just not work.

I tried looking at these sites and went through the list of global expressions as well but couldn't find any examples similar to mine or a direction in which to look further.

http://jinja.pocoo.org/docs/templates/#if

http://wsgiarea.pocoo.org/jinja/docs/conditions.html

   {% for repo in RepoName %}
       <tr>
          <td> <a href="http://mongit201.be.monster.com/icinga/{{ repo }}">{{ repo }}</a> </td>
       {% if error in RepoOutput[RepoName.index(repo)] %}
          <td id=error> {{ RepoOutput[RepoName.index(repo)] }} </td> <!-- I want this in green if it is up-to-date, otherwise I want it in red -->
       {% elif Already in RepoOutput[RepoName.index(repo) %}
          <td id=good> {{ RepoOutput[RepoName.index(repo)] }} </td>   <!-- I want this in green if it is up-to-date, otherwise I want it in red -->
       {% else %}
            <td id=error> {{ RepoOutput[RepoName.index(repo)] }} </td> <!-- I want this in green if it is up-to-date, otherwise I want it in red -->
       </tr>

       {% endif %}
   {% endfor %}

Thanks

Answer

Martijn Pieters picture Martijn Pieters · Feb 25, 2014

You are testing if the values of the variables error and Already are present in RepoOutput[RepoName.index(repo)]. If these variables don't exist then an undefined object is used.

Both of your if and elif tests therefore are false; there is no undefined object in the value of RepoOutput[RepoName.index(repo)].

I think you wanted to test if certain strings are in the value instead:

{% if "error" in RepoOutput[RepoName.index(repo)] %}
    <td id="error"> {{ RepoOutput[RepoName.index(repo)] }} </td>
{% elif "Already" in RepoOutput[RepoName.index(repo) %}
    <td id="good"> {{ RepoOutput[RepoName.index(repo)] }} </td>
{% else %}
    <td id="error"> {{ RepoOutput[RepoName.index(repo)] }} </td>
{% endif %}
</tr>

Other corrections I made:

  • Used {% elif ... %} instead of {$ elif ... %}.
  • moved the </tr> tag out of the if conditional structure, it needs to be there always.
  • put quotes around the id attribute

Note that most likely you want to use a class attribute instead here, not an id, the latter must have a value that must be unique across your HTML document.

Personally, I'd set the class value here and reduce the duplication a little:

{% if "Already" in RepoOutput[RepoName.index(repo)] %}
    {% set row_class = "good" %}
{% else %}
    {% set row_class = "error" %}
{% endif %}
<td class="{{ row_class }}"> {{ RepoOutput[RepoName.index(repo)] }} </td>