Hi - I'm looking for packing suggestions for women's attire in the Barcelona/Tarragona area in early July.

I think it will be pretty hot, but not entirely sure, since it is close to the sea. Are capri slacks and sandals ok for most areas? Is that too casual for a restaurant- say middle of the road restaurant (not too fancy, but not tapas bar)?

Last time I went to Spain it was winter, and the last time I went in the summer I was 7, so I'm a little lost on summer fashion in Spain. Or I should say, I at least want to be presentable.

Thanks for any suggestions!

Both Barcelona and Tarragona are "touristy" areas, and are therefore used to seeing foreigners wearing what they feel comfortable in.
In Barcelona in particular you will see many whole families dressed in Premier league football shirts. So I wouldn't worry about your capris and sandals. From my own travel experience restaurants seem to be more aware (and critical) of how men are dressed when wishing to dine.