issue_comments

I'm not going to do the base64 thing unless someone asks for it.

https://latest.datasette.io/fixtures?sql=select+rowid%2C+data+from+binary_data+order+by+rowid+limit+101 now looks like this:

I'm going to link to. the new .blob representation using the new ?_blob_hash=xxx argument to ensure that the content served is the expected binary blob.

This will close #1034.

Moving the CSV work to a separate issue.

Remove this xfail and import pytest: https://github.com/simonw/datasette/blob/503a5b7b4080a26ef9ceb1ecd1a4a6f4ef4ffc59/tests/test_csv.py#L83-L96

Those display_rows have already been processed by the render_cell plugin hook: https://github.com/simonw/datasette/blob/d6f9ff71378c4eab34dad181c23cfc143a4aef2d/datasette/views/database.py#L320-L346

Next challenge: link to .blob downloads from https://latest.datasette.io/fixtures?sql=select+rowid%2C+data+from+binary_data

This will be a bit tricky. Here's how that template works at the moment: https://github.com/simonw/datasette/blob/d6f9ff71378c4eab34dad181c23cfc143a4aef2d/datasette/templates/query.html#L69-L77

Relevant code: https://github.com/simonw/datasette/blob/d6f9ff71378c4eab34dad181c23cfc143a4aef2d/datasette/views/base.py#L258-L345

Idea: what if Datasette had a custom SQLite function that could be used to generate URLs to the row-level BLOB download for a value? Then custom SQL query authors could use that function to link to the relevant content.

This could be expanded to exposing other datasette.urls functionality as well.

I'll do the rest of the work on this in the pull request #1061.

I'll use hashlib.sha256 for these hashes.

The reason I like the ?_blob_hash= solution is that it feels really misleading to provide a link to "download this binary" which could conceivably download some other data.

Had an idea in https://github.com/simonw/datasette/issues/1051#issuecomment-718980659

OK, alternative idea. The .blob output renderer from #1050 gets to see multiple rows at once.

For an arbitrary SQL query, how about if I link to this?

/db.blob?sql=...&_blob_column=data&_blob_hash=bc4c24181ed3ce666

Then the output renderer loops through all of the data results that are available to it and, if one of them hashes to that value, serves up that data?

If no matches are found it can show an error message telling you that the link has expired (presumably because the underlying database has changed since the link was generated).

I think this might be the best solution to the problem.

OK, alternative idea. The .blob output renderer from #1050 gets to see multiple rows at once.

For an arbitrary SQL query, how about if I link to this?

/db.blob?sql=...&_blob_column=data&_blob_hash=bc4c24181ed3ce666

Then the output renderer loops through all of the data results that are available to it and, if one of them hashes to that value, serves up that data?

If no matches are found it can show an error message telling you that the link has expired (presumably because the underlying database has changed since the link was generated).

I think this might be the best solution to the problem.

https://docs.datasette.io/en/latest/writing_plugins.html#designing-urls-for-your-plugin

Yes, confirmed - this is a bug where if the BLOB column contains a null you get a nasty exception if you try to download it.

@thadk from that error it looks like the problem may have been that you had a BLOB column containing a null value? If so that's definitely a bug, I'll fix that.

thebe is the first time I've seen a library that requires you to set up some global JavaScript configuration before loading the script itself.

I'm hesitant to add an extra template block just to cover that one case since it's such a rare pattern. But it's important that thebelab can be used with Datasette.

Would this pattern work for you instead?

```html+jinja {% block extra_head %}

{% endblock %} ```

You could use Datasette's new {{ urls.static_plugins(...) }} template option - see https://docs.datasette.io/en/latest/internals.html#internals-datasette-urls - to generate a link to code that was bundled with the plugin:

```html+jinja {% block extra_head %}

{% endblock %} ```