Table footer about django-tables2

[bradleyayers]

What was your specific use-case? The first one that comes to mind for me, would be a totals row, however I think this would appear strange if the table was paginated. In the context of pagination, should the footer show data specific to the current data on the page, or specific to all data in the table?

Just a few problems that come to mind, thoughts? Any ideas on an API for this?

[bradleyayers]

This can be achieved now in v0.8.0 by writing a custom template:

{% extends "django_tables2/table.html" %}

{% block table.tfoot %}
<tfoot>
    <tr>
        <td colspan="3">three column spanning footer</td>
    </tr>
</tfoot>    
{% endblock %}

It can be hooked up to the table via:

class FootedTable(tables.Table):
    # ... columns

    class Meta:
        template = "path/to/footed_template.html"

[blite]

I think this is still needed, but as a special type of row that totals up the whole dataset

[bradleyayers]

Could you propose an API for this

[blite]

just a quick look over this it seems like you'd need different column types to be able to automatically calculate it. You could however quite easily insert a hook into the iter method of BoundRows to return a total if a certain function existed

def render_total(self, columns):
    #columns is a dict of all the columns with initial value set to None
    #render None as N/A
    return columns   

[bradleyayers]

Perhaps a render_footer method on Column that would return HTML for a footer cell, and allow subclasses to extend it. However this raises a few questions:

• How does render_footer access data to use to calculate an output value.
• In the context of pagination, should the footer be for the current page, or all pages.
• Should (and if so how) multiple footer rows be supported.

[blite]

that's definitely better because you could re-use some of the logic to actually render the values. I don't think multiple footer rows would be that common, but if you wanted to build it in a way to support them you could just consider the footer to be similar to rows. I don't personally use the pagination, but I think it would be more intuitive to total the rows currently displayed.

{% block table.tfoot %}
<tfoot>

    {% for row in table.footer %}
      <tr>  
      {% for column, cell in row.items %}
          <th>{{ cell }}</th>
      {% endfor %}
      </tr>    
    {% endfor %}

</tfoot>    
{% endblock %}  

[blite]

for now I ended up doing the above plus this:

    def __init__(self, form, request, *args, **kwargs):
        rf_values = form.get_values()
        rf_annotations = form.get_annotations()
        rf_filter = form.get_filter()
        rf_calculations = form.get_calculations()                  
        data = list(HourlyStat.objects.filter(**rf_filter
                    ).values(*rf_values
                    ).annotate(**rf_annotations).order_by('-clicks')) 
        super(StatsTable, self).__init__(data, *args, **kwargs)      
        columns = rf_values + rf_annotations.keys() + rf_calculations
        for col in columns:
            self.base_columns[col] = tables.Column()
        f_data = dict.fromkeys(columns, 0)
        for k in f_data.keys():
            if k in rf_annotations.keys():
                f_data[k] = sum([x[k] for x in data])
        self.footer_data = self.TableDataClass(data=[f_data], table=self)
        self.footer = BoundRows(self.footer_data)    

[thebookworm101]

I'm in need of a way to create a totals column row in m my table, is there a way to do that yet? im unable to follow the code snippets by blite above

[bradleyayers]

I assume you mean a totals row, and if so, what should its behavior be in regards to pagination?

[thebookworm101]

um, yes that's what meant to say, thanks for the correction, about pagination im thinking the totals should occur at the very end of the table (im not expecting anything else to make sense for my use-case since its a time delta column with float values) , or but since i have different tables, i could have them on a per table basis, something like that.
EDIT:
Is there a way of accessing the column data so i can add it up or is there already a way of doing that?

[bradleyayers]

So you mean you'd only see the totals row on the last page?

[thebookworm101]

yes, only on the last page