Create a block to display Search banter

[bobbingwide]

In the SB theme we need to display some additional Search Banter on the search results page.
For details of what the block needs to display see the Search results section in bobbingwide/sb#24

Proposed solution

• Implement a server side rendered block called bigram/search-banter.
• The code used in genesis-SB needs to be copied and cobbled to provide the banter when the main query is a search.

Implementation notes

• The bigram plugin will need to be changed to a multiple entry point plugin - similar to oik - see Update to the latest @wordpress/scripts package and rework as required oik#202
• I understand the latest version of the wp-scripts routine already supports this.
• It would be good to try updating bigram to the latest build before adding the new block.

[bobbingwide]

Steps to update the existing bigram/seen-before block

• Update wp-scripts using npm run packages-update
• Move the block's src files into separate folder within src/seen-before
• Move the block.json file into the same folder.
• Change the block's block.json file to refer to the appropriate entry-point and CSS
• Update server logic to load the block.json from the build folder
• Build using npm run dev
• Test

Not necessary since the block's not internationalized.

• Call wp_set_script_translations() for each block's editor-script
• Correct the filter function for load_script_textdomain_relative_path

Steps to add the new bigram/search-banter block

• Create a new subdirectory src/search-banter
• Copy and cobble source files from seen-before
• Add the block registration in bigram_block_block_init
• Develop the new dynamic block's server side rendering function bigram_block_dynamic_block_search_banter

[bobbingwide]

The lastest documentation for wp-scripts implies that it's possible to create multiple entry points automatically

When using the start or build commands, the source code directory ( the default is ./src) and its subdirectories are scanned for the existence of block.json files. If one or more are found, they are treated a entry points and will be output into corresponding folders in the build directory. This allows for the creation of multiple blocks that use a single build process.

See https://developer.wordpress.org/block-editor/reference-guides/packages/packages-scripts/#automatic-block-json-detection-and-the-source-code-directory

I couldn't get this to work.
No matter what value I entered for editorScript in block.json I got messages from the build and nothing was output.

In the end I used the same solution as for oik, a custom webpack.config.js, but changed the server side registration to use the build folder rather than the src folder.