What does the phrase "dann doch noch schnell" mean? As in
Ich habe mir heute dann doch noch schnell einen neuen Hartschalenkoffer gekauft.
is this some kind of an idiom?
EN-A: I bought a new hard-shell suitcase.
(Here dann/then is an adverb used to denote a point in time or a conjunctive with antecedent implied.)
EN-B: I then bought a new hard-shell suitcase.
(doch is a modal particle.)
EN-C1: I then bought a new hard-shell suitcase , after all.
EN-C2: I went and bought a new hard-shell suitcase , after all.
So far, so good.
EN-D: At the last minute, I did buy a new hard-shell suitcase.
Translating (A) through (C) was straightforward, but (D) required some rearranging. The import of the modal particle doch that before was translated to after all now is expressed by the auxiliary verb did, used as a marker for emphasis.
What happened to dann? Airbrushed out of the picture in the English translation... but no one misses it :) More seriously, the character of dann changed about halfway through this little sequence of constructive exercises, from a likely marker of a point in time to an enhancer for the modal particle doch.
But as with enhancers in food preparation (monosodium glutamate being the best known among them) opinions may differ as to their relevance. Some people complain if you leave MSG out, some get a headache, and others simply don't care or don't notice a difference.
If you asked a sample of Germans whether they would prefer the sentence DE-D with or without dann, most would prefer it with. They would justify their choice by explaining that dann intensifies doch and is therefore performing a function. However, if you asked them to come up with a situation where leaving out dann would make a difference in communication, they would be unable to come up with an example. Hence I think that people prefer dann doch to doch alone because they feel it rolls off the tounge more nicely and not because it changes the message in any way.
Although the Question did not ask specifically about translation into English, I used the above translation exercises in order to build from the simple to the complex. Hence it may not be out of place to note that [dann doch] is a good example of why it makes sense not to translate slavishly word for word.
Es ist keine fest stehende Phrase, wie man leicht zeigen kann. Ausgangspunkt ist dieser Satz:
bei dem das
Wir können nun jedes einzelne Wort der Kombination entfernen, und erhalten immer wieder übliche Aussagen, die nur leicht modifiziert sind durch das jeweils fehlende Wort:
Ebenso kann man zwei Wörter streichen:
Auch drei Wörter lassen sich löschen:
Und auch alle vier:
Das zeigt, dass
Summing up my comments to the other answers, "dann doch noch schnell" means:
I should add that this is my subjective opinion of what I want to say when I use that phrase. Other users might come from a different meaning and express it in the same words. Language, after all, is not an exact science.
You have to break it down: dann | doch noch | schnell
dann = then, schnell = quickly/swiftly/in passing/
The collocation 'doch noch' (roughly: 'yet still, after all') is used to express that an action or event takes place unexpectedly after it had already been deemed unlikely, impossible, or undesirable given particular circumstances or a development of a situation, e.g. time running out, a bad start, a previous negative decision, prognosis, or a desired state.
In your example sentence, the narrator might have previously decided that they had no time to buy a suitcase or that it wasn't necessary, but still bought one in spite of that.
However, 'doch noch' can occur outside this collocation, e.g.: «Aber ich habe doch | noch nie | etwas Böses getan!» (But I've | never yet | done anything evil!) Here the main collocation is 'noch nie' (never yet), while 'doch' has the role of a modal particle as used in colloquial speech to emphasize the claim expressed in the sentence ('But, I've never yet/ever done anything evil as a matter of fact, so, why would I be blamed/punished?')
Here is my try. All in italic is what the following [words] express/ feel like to me.
Well, after all (and despite previous plans) [dann and doch] I (actually) did [doch again] buy a suitcase just/right [schnell] before I did that other thing else/something else happened (that the listener probably knows about[noch].
I tried to capture the tone that each word adds. I am aware of the fact that this isn't really what an English native speaker would say.
So according to Eugene Seidel's and TehMacDawg's answer, there are two possible ways to interpret and consequently structure and translate "dann doch noch schnell".
The difference is small:
Although undecidable in written form, both forms can possibly be differentiated in verbal form:
Is like "by the way" and can have can have several meanings.
For example: you thought about buying something but declined it. But when you are shopping and see the thing you did not want to buy but suddenly buy it, you can say "dann doch noch schnell".
I gave you example with buying because your example was about buying something. You can transfer it to several things like doing something, organizing, watching...
And it is an idiom in context of a phrase.
I hope my answer was clear and helpful :D