Steps to reproduce

Create a serializer with an IntegerField (or a ModelSerializer for a model with an IntegerField).

In the view, set the renderer to be TemplateHTMLRenderer.

If there is a zero value stored for the field into the DB, then the input field in the generated HTML has no value set:

<input name="x" class="form-control" type="number">

This make sense if the value was None but not if the value is 0.

Expected behavior

The generated HTML code should be for 0 value:

<input name="x" class="form-control" value="0" type="number">

Actual behavior

The following HTML code is generated:

<input name="x" class="form-control" type="number">

Suspicion

I suspect the problem is in input.html, in the line

<input name="{{ field.name }}" {% if style.input_type != "file" %}class="form-control"{% endif %} type="{{ style.input_type }}" {% if style.placeholder %}placeholder="{{ style.placeholder }}"{% endif %} {% if field.value %}value="{{ field.value }}"{% endif %} {% if style.autofocus and style.input_type != "hidden" %}autofocus{% endif %}>

The {% if field.value %}value="{{ field.value }}"{% endif %} may be evaluated as False because value is 0.