render as html

[srijani-smsrc]

so i have used render as html , and i have put span in custom sql metric in table chart m but when i am downloading as excel or csv , the value and the span code is getting downloaded not just the value

@dosu

[dosubot[bot]]

This is expected behavior — "Render as HTML" only controls how values are displayed in the browser. When you export to CSV/Excel, Superset pulls the raw query results directly, so your <span> tags come through as-is in the export [1].

Recommended fix: Use Conditional Formatting instead

If your goal is just coloring values, use Superset's built-in Conditional Formatting (under the "Customize" tab in the Table chart). This applies colors natively without injecting HTML into the metric, so exports will contain only clean values.

Other workarounds:

1. Post-process in Excel — Use Find & Replace or =SUBSTITUTE() to strip the span tags after export.
2. Backend modification — If you want to strip HTML globally for all exports, you can modify superset/common/query_context_processor.py in the get_data() method by adding regex-based HTML stripping before the CSV/Excel conversion:

import re

# Add after verbose_map processing, before CSV/Excel conversion:
for col in df.columns:
    if df[col].dtype == "object":
        df[col] = df[col].apply(
            lambda x: re.sub(r'<[^>]+>', '', x) if isinstance(x, str) else x
        )

[1]

The conditional formatting approach is the cleanest solution since it separates styling from data entirely.

To reply, just mention @dosu.

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[FrancescoCastaldi]

This happens because "Render as HTML" in the Table chart is strictly a client-side frontend display feature.

Why the HTML tags appear in exports

When you click Download CSV or Download Excel, Superset does not scrape the rendered browser DOM. Instead, it sends an API request directly to /api/v1/chart/data with format csv or xlsx. The backend database query executes, and the raw SQL result set is exported directly to file. Because your <span> tags were generated inside the SQL metric string, the CSV/Excel file receives the raw SQL string.

How to achieve styled display in the browser and clean exports

Solution 1: Use Native Conditional Formatting instead of HTML in SQL (Best Solution)

Instead of embedding <span> tags in your Custom SQL, write your metric to return the pure, clean numeric or string value (e.g., SUM(sales)).

Then, use Superset's native formatting controls:

1. In the Table chart configuration in Explore, switch to the Customize tab.
2. Scroll to the Conditional Formatting section.
3. Click Add color formatting rule.
4. Configure your visual logic (for example: if value > 100, color green; if value < 0, color red).

Result: The browser displays rich color highlights and badges, while CSV and Excel exports download 100% clean numbers without HTML markup.

Solution 2: Expose Separate Display and Export Columns

If you require complex HTML that conditional formatting cannot replicate:

1. In your dataset, maintain two columns:
   • metric_raw: clean numeric or plain text value.
   • metric_html: contains the formatted <span ...>...</span> string.
2. In the Table chart, you can display metric_html for online dashboard users, and provide an alternate export-oriented view or use SQL REPLACE() / regex stripping in a custom export post-processor.