Emmet expands abbreviations in limited syntaxes only: HTML, CSS, LESS, SCSS, Stylus and PostCSS.
The reason to restrict Tab handler to a limited syntax list is because it breaks native Sublime Text snippets.
If you want to abbreviation with Tab in other syntaxes (for example, JSX, HAML etc.) you have to tweak your keyboard shorcuts settings:
add expand_abbreviation_by_tab command for tab key for required syntax scope selectors.
To get current syntax scope selector, press ⇧⌃P (OSX) or Ctrl+Alt+Shift+P, it will be displayed in editor status bar.
Go to Preferences > Key Bindings — User and insert the following JSON snippet with properly configured scope selector instead of SCOPE_SELECTOR token:
{
"keys": ["tab"],
"command": "expand_abbreviation_by_tab",
// put comma-separated syntax selectors for which
// you want to expandEmmet abbreviations into "operand" key
// instead of SCOPE_SELECTOR.
// Examples: source.js, text.html - source
"context": [
{
"operand": "SCOPE_SELECTOR",
"operator": "equal",
"match_all": true,
"key": "selector"
},
// run only if there's no selected text
{
"match_all": true,
"key": "selection_empty"
},
// don't work if there are active tabstops
{
"operator": "equal",
"operand": false,
"match_all": true,
"key": "has_next_field"
},
// don't work if completion popup is visible and you
// want to insert completion with Tab. If you want to
// expand Emmet with Tab even if popup is visible --
// remove this section
{
"operand": false,
"operator": "equal",
"match_all": true,
"key": "auto_complete_visible"
},
{
"match_all": true,
"key": "is_abbreviation"
}
]
}