# Typed table block

The `typed_table_block` module provides a StreamField block type for building tables consisting of mixed data types. Developers can specify a set of block types (such as `RichTextBlock` or `FloatBlock`) to be available as column types; page authors can then build up tables of any size by choosing column types from that list, in much the same way that they would insert blocks into a StreamField. Within each column, authors enter data using the standard editing control for that field (such as the Draftail editor for rich text cells).

## Installation

Add `"wagtail.contrib.typed_table_block"` to your `INSTALLED_APPS`:

```python
INSTALLED_APPS = [
    ...
    "wagtail.contrib.typed_table_block",
]
```

## Usage

`TypedTableBlock` can be imported from the module `wagtail.contrib.typed_table_block.blocks` and used within a StreamField definition. Just like `StructBlock` and `StreamBlock`, it accepts a list of `(name, block_type)` tuples to use as child blocks:

```python
from wagtail.contrib.typed_table_block.blocks import TypedTableBlock
from wagtail import blocks
from wagtail.images.blocks import ImageChooserBlock

class DemoStreamBlock(blocks.StreamBlock):
    title = blocks.CharBlock()
    paragraph = blocks.RichTextBlock()
    table = TypedTableBlock([
        ('text', blocks.CharBlock()),
        ('numeric', blocks.FloatBlock()),
        ('rich_text', blocks.RichTextBlock()),
        ('image', ImageChooserBlock())
    ])
```

To keep the UI as simple as possible for authors, it’s generally recommended to use Wagtail’s basic built-in block types as column types, as above. However, all custom block types and parameters are supported. For example, to define a ‘country’ column type consisting of a dropdown of country choices:

```python
table = TypedTableBlock([
    ('text', blocks.CharBlock()),
    ('numeric', blocks.FloatBlock()),
    ('rich_text', blocks.RichTextBlock()),
    ('image', ImageChooserBlock()),
    ('country', ChoiceBlock(choices=[
        ('be', 'Belgium'),
        ('fr', 'France'),
        ('de', 'Germany'),
        ('nl', 'Netherlands'),
        ('pl', 'Poland'),
        ('uk', 'United Kingdom'),
    ])),
])
```

On your page template, the `{% include_block %}` tag (called on either the individual block, or the StreamField value as a whole) will render any typed table blocks as an HTML `<table>` element.

```html+django
{% load wagtailcore_tags %}

{% include_block page.body %}
```

Or:

```html+django
{% load wagtailcore_tags %}

{% for block in page.body %}
    {% if block.block_type == 'table' %}
        {% include_block block %}
    {% else %}
        {# rendering for other block types #}
    {% endif %}
{% endfor %}
```

## Custom validation

As with other blocks, validation logic on `TypedTableBlock` can be customized by overriding the `clean` method (see [StreamField validation](../../advanced_topics/streamfield_validation.md#streamfield-validation)). Raising a `ValidationError` exception from this method will attach the error message to the table as a whole. To attach errors to individual cells, the exception class `wagtail.contrib.typed_table_block.blocks.TypedTableBlockValidationError` can be used - in addition to the standard `non_block_errors` argument, this accepts a `cell_errors` argument consisting of a nested dict structure where the outer keys are row indexes and the inner keys are column indexes. For example:

```python
from django.core.exceptions import ValidationError
from wagtail.blocks import IntegerBlock
from wagtail.contrib.typed_table_block.blocks import TypedTableBlock, TypedTableBlockValidationError


class LuckyTableBlock(TypedTableBlock):
    number = IntegerBlock()

    def clean(self, value):
        result = super().clean(value)
        errors = {}
        print(result.row_data)
        for row_num, row in enumerate(result.row_data):
            row_errors = {}
            for col_num, cell in enumerate(row['values']):
                if cell == 13:
                    row_errors[col_num] = ValidationError("Table cannot contain the number 13")
            if row_errors:
                errors[row_num] = row_errors

        if errors:
            raise TypedTableBlockValidationError(cell_errors=errors)

        return result
```