AppCode 2020.3 Help

Code completion

This section covers various techniques of context-aware code completion that allow you to speed up your coding process.

Basic completion

Basic code completion helps you complete the names of classes, methods, and keywords within the visibility scope. When you invoke code completion, AppCode analyses the context and suggests the choices that are reachable from the current caret position (suggestions also include Live templates).

Invoke basic completion

  1. Start typing a name. By default, AppCode displays the code completion popup automatically as you type. If automatic completion is disabled, press ⌃Space or choose Code | Code Completion | Basic from the main menu.

  2. To narrow down the suggestions list, type any part of the expected name or keyword (even characters from somewhere in the middle are accepted) or invoke code completion after a dot separator. AppCode shows the suggestions that include the typed characters in any positions.

    In case of CamelCase or snake_case names, you can type the initial letters only, and AppCode will show appropriate suggestions.

    Basic completion with camel case
  3. Accept an appropriate suggestion pressing . You can also do the following:

    • Double-click a list item to insert it to the left of the caret.

    • Press to replace the characters to the right from the caret.

    • Use ⌃⇧⏎ to make the current code construct syntactically correct (balance parentheses, add missing braces and semicolons, and so on).

Smart completion

Smart code completion filters the suggestions list and shows only the types applicable to the current context. For example, it can suggest a constructor or factory method of a class expected.

Invoke smart completion

  1. Start typing. By default, AppCode displays the code completion popup automatically as you type. If automatic completion is disabled, press ⌃⇧Space or choose Code | Code Completion | SmartType from the main menu.

  2. Press ⌃⇧Space or choose Code | Code Completion | SmartType from the main menu.

    Smart type completion

  3. If necessary, press ⌃⇧Space once again. AppCode will look up values of the expected type which can be retrieved through a chained method call.

Statement completion

You can create syntactically correct code constructs by using statement completion. It inserts the necessary syntax elements (parentheses, braces, and semicolons) and gets you in a position where you can start typing the next statement.

Complete a method declaration

  • Start typing a method declaration and press ⌃⇧⏎.

    Complete a method declaration

Complete a code construct

  • Start typing a code construct and press ⌃⇧⏎.

    AppCode automatically completes the construct and adds the required punctuation. The caret is placed at the next editing position.

    Complete a code construct

Hippie completion

Hippie completion is a completion engine that analyses your text in the visible scope and generates suggestions from the current context. It helps you complete any word from any of the currently opened files.

Hippie completion

Expand a string at caret to an existing word

  1. Type the initial string and do one of the following:

    • Press ⌥/ or choose Code | Code Completion | Cyclic Expand Word to search for matching words before the caret.

    • Press ⌥⇧/ or choose Code | Code Completion | Cyclic Expand Word (Backward) to search for matching words after the caret and in other open files.

    The first suggested value appears, and the prototype is highlighted in the source code.

  2. Accept the suggestion, or hold the Alt key and keep pressing / until the desired word is found.

Postfix code completion

Postfix code completion helps you reduce backward caret jumps as you write code. You can transform an already-typed expression to a different one based on a postfix you type after the dot, the type of expression, and its context.

  • To view a full list of available postfix templates, in the Preferences dialog ⌃⌥S, go to Editor | General | Postfix Completion.

  • Select , Space, or to expand postfix templates.

Transform a statement with a postfix

  • Type an expression and then type a postfix after a dot, for example, .if:

    function m(arg) { arg.if }

    The initial expression gets wrapped with an if statement:

    function m(arg) { if (arg) { } }

You can edit the predefined postfix templates, for example, to replace a long key with a shorter one, or to expand the list of applicable expression types.

Create custom postfix templates

  1. In the Preferences dialog ⌃⌥S, go to Editor | General | Postfix Completion.

  2. Click the Add button (the Add button) on the toolbar.

  3. Specify the Key that is the combination of symbols that will invoke the template. Select which expression types the new template will be applicable to, and type the target expression in the following format: $EXPR$ <target_expression>, for example, $EXPR$ =!null.

Completion of tags and attributes

AppCode automatically completes names and values of tags and attributes in many file types:

Completion of tags and attribute names is based on the DTD or Schema the file is associated with. If there is no schema association, AppCode will use the file content (tag and attribute names and their values) to complete your input.

Complete tag names

  1. Press < and start typing the tag name. AppCode displays the list of tag names appropriate in the current context.

    Tags completion

    Use the Up and Down buttons to scroll through the list.

  2. Press to accept a selection from the list. If your file is associated with a schema or a DTD, AppCode automatically inserts the mandatory attributes according to it.

Configure code completion settings

Configure completion options

  1. In the Preferences dialog ⌃⌥S, select Editor | General | Code Completion.

    • To automatically display the suggestions list, select the Show suggestions as you type checkbox. If the checkbox is cleared, you have to call code completion explicitly by pressing ⌃Space for basic completion or ⌃⇧Space for smart completion.

      You can also choose to automatically insert suggestions when there's just one option: select the completion type under Automatically insert single suggestions for.

    • To sort suggestions in the alphabetical order, instead of sorting them by relevance, select the Sort suggestions alphabetically checkbox.

      You can also toggle these modes by clicking the Sort Alphabetically button or the Sort by Relevance button respectively in the lower-right corner of the suggestions list.

    • If you want word case not to be taken into account (like in Xcode, for example), uncheck Match case.

    • If you want the documentation popup to be displayed automatically for each item in the suggestions list as you scroll it, select the Show documentation popup in option. In the field to the right, specify the delay (in milliseconds), after which the popup should appear.

Completion tips and tricks

View reference

  • You can use the Definitions by pressing ⌃⇧I when you select an entry in the suggestions list:

    Quick definition in completion
  • You can use the Quick Information view by pressing ⌃Q when you select an entry in the suggestions list:

    Quick documentation

Use method parameters placeholders

When you choose a method call from the suggestions list, the IDE inserts placeholders for argument values that include a name and a type of a parameter:

Parameters placeholders

Upon completing selection from the suggestion list, you can replace the placeholders with the actual arguments values.


    If code completion doesn't work, this may be due to one of the following reasons:

    • The Power Save Mode is on (File | Power Save Mode ). Turning it on minimizes power consumption of your laptop by eliminating the background operations, including error highlighting, on-the-fly inspections, and code completion.

    • An SDK is not configured for your project.

    • Your file doesn't reside in a content root, so it doesn't get the required class definitions and resources needed for code completion.

    • A file containing classes and functions that you want to appear in completion suggestions list is marked as a plain text file.

    • External libraries that contain functions that you want to appear in the completion suggestions list are not added as dependencies or global libraries.

    Last modified: 15 March 2021