Show search results in context

[dcabo]

Either by default or after expanding via a link, it would be useful to show the found sentence surrounded by its context. If we had great blocks (#7) we could just show that, but that's going to take a while and we don't know how good it will be anyway. So we could:

• Show sentences in the n seconds before/after the results. I think this is a straightforward query in Elastic.

• Show n sentences before/after. We'd need to add an index to every sentence when loading.

There're subtle differences between the two approaches, but don't know which one is better: if we find the first sentence after a long silence, do we want to show the last sentence from the previous block as context or not? It probably doesn't matter much in practice though.

[dcabo]

He hecho esto, que implica hacer cambios en todas las capas: una nueva consulta a Elastic, pasar los datos a Vue, presentarlos. No me he molestado en ponerlo demasiado bonito de momento, pero el resto está.

He aprovechado para ocultar lo del vídeo embebido, que no salta al segundo correcto #27.