Dialogs are designed to help you gather multi-part input from end-users in a structured way; think, for example, of a helpdesk ticket that contains a freeform description of an issue, but also requires some category labels for triage.
They're best used for quick, contextual work: brief tasks that get some benefit from being completed in the context of a channel or conversation. Here are some tips on how to make them most useful and usable.
Dialogs appear as a modal window inside Slack. Within that modal, you can add one or many input fields in the form of single line text inputs, text areas, and dropdowns.
In general, the easier it is to enter information into a dialog, the more likely your users are to fill them out to completion. Wherever possible, favor structured inputs over freeform text, and work to keep the total length relatively short.
In order to look best on mobile as well as desktop, we suggest that modal titles be short. Our tips on choosing words for messages generally apply: keep modal titles sentence-cased; pick action verbs for buttons that confirm what the user is doing.
placeholder value for all field elements to better communicate purpose independent of the user's interface.
These are best used for concise answers with established bounds or options, e.g. office location, age range, or dietary preference. Keep dropdown options short, and remember to test how they render on mobile devices.
Text input fields are capped at 150 characters, and are best used for concise freeform answers, like name or ticket title.
If inputs are better served with pre-selected answers (e.g. age ranges, department), consider using a dropdown. If you expect input to be longer than 150 characters, consider using a text area.
Text areas are good for open-ended questions that need more room, like meeting notes or interview feedback. Most dialogs should not have more than one or two text areas; remember that keeping the input brief and contextual will help ensure that people complete the forms.
Not like this: