IDE Snippets

The Gambas IDE provides a modifiable set of coding shortcuts that an ease typing effort in the IDE considerably. Entering a code shortcut at the beginning of a line and pressing the TAB key will automatically expand the shortcut into a defined piece of code.

The standard shortcuts provided with the IDE can be seen on the Code formatting tab of the Preferences form. At the bottom of the tab is a scrollable list of trigger strings and the associated expansion macros.

Using IDE Snippets

Activating / Deactivating

In order to use IDE Snippets when coding, the Activate Code Snippets checkbox must be selected in the Preferences. If not then pressing a TAB after entering a trigger string will simply insert a TAB character on the current code line.

IDE Snippets expand and include the inbuilt code completion features of Gambas.

A Few Commonly Used Examples

p TAB will insert a property declaration. The cursor will be positioned at the point where the property name can be inserted. The selected text can simply be over-typed. Pressing TAB again will position the cursor at the point for entry of the property data type. Finally pressing Enter will commit the snippet expansion and return usage of the IDE editor back to its' "normal" state.

f TAB will insert a function declaration block. Again the cursor will be positioned for entry of the function name. However in this case, pressing the TAB more times will move through the entry points for the function name, the signature, the return type and finally to the point of entry of your first line of code for the function. Note that in this case, the IDE editor has appeared to return to "normal operations". In fact, the snippet parser is still in operation and remains so until you move the cursor outside the function block. So, for example, if you overlooked entering the return type, positioning the cursor back anywhere on the declaration line and pressing Tab will highlight that overlooked expansion macro token.

A few other triggers you may like to investigate are:

  • main TAB : generates a Main sub.

  • fe TAB : generates a For Each ... Next block

  • d TAB and di tab and other derivatives : generates Dim lines

  • (my favorite!) gpl Tab : generates the GPL short statement

Finally, if the initial expansion isn't what you wanted at all, just press Ctrl + z to get back your original typing.

Expansion Macros

You can define your own IDE Snippets!

Again, on the Preferences form, Code formatting tab next to the list of snippets are the buttons to create, change or delete custom snippets (it will also let you see the standard ones in read-only mode - handy if you want to copy the existing macro). To create a new snippet click the New... button. You are presented with a form containing two controls, a textbox for entering the trigger string and an editor for entering the expansion macro.

If you attempt to use a trigger string that is already defined, the IDE will pop up a balloon "This trigger string is already in use." when you try to save the snippet.

Syntax

The syntax for IDE Snippets is very simple but can take some getting used to. There are two parts, as indicated above, the trigger string and the expansion macro.

Trigger Strings

The trigger string can be any character string without inner spaces. However, it is probably safer to use lower case alpha or alpha+numeric strings. Not too difficult eh!

Expansion Macros

Expansion macros have three aspects.

Literal code

which is any sequence of characters and escaped characters not included below. So text like

If IsInteger(sText) Then

Return False

will be inserted as is including the leading spaces, newlines and tabs (that you will see as escape sequences in the Preferences list). In fact, inserting escape sequences in the macro should be avoided unless they are part of a literal string, as they will be double escaped in the internal macro code.

(Yes, even the typo will be entered verbatim.)

Insertion points

indicate where the cursor will be positioned after expansion. They are indicated by a sub-string ${n:lit_token} in the code where n is the ordinal cursor position of the token and lit_token is the text that will be displayed and highlighted for that token. So

? ${1:Variable}

will result in

? Variable

(which will automatically expand to "Print ..." when you leave that line.)

Project Metadata

The macro expansion also allows you to insert a few bits of project metadata in your macro. The metadata currently available is:

  • The project title. (use a ${n:$TITLE} token)

  • The project description. (use a ${n:$DESCRIPTION) token), and

  • The project author. (use a ${n:$AUTHOR} token)