Postfix templates help you transform expressions that you have already typed without jumping backwards — just type a dot after an expression and pick a template from the completion list.
Applying postfix templates
One of the simplest examples of postfix templates is negating a boolean expression. Suppose you have just typed a boolean expression and then realized that the comparison logic should be reversed. Normally, you have to move your caret back and change
!= or vice versa, and then return to where you were. With JetBrains Rider, you can just continue typing
.not and press Enter.
There are a lot more postfix templates that you can use to speed up coding. For example, you can wrap the current expression with
await in front of the current expression, iterate over a collection, generate a switch statement, cast the expression to a specific type, or even introduce a field or property for the expression.
Postfix template could even change your typing routine. Consider the
CheckInput method below and imagine how you would type the null-checking clause.
Now let's see how you could do it with postfix templates.
As soon as your caret is in the method body, you can start typing
input right away because that is what you want to check. When the
input is there, just continue typing
.null - a postfix template for checking the expression for
This will compare
null and wrap the comparison in an
if statement, and set your caret in the position where you can continue typing:
Now, instead of typing
throw, you can go ahead with typing the exception class name, and invoke the
.throw template after it:
After applying this template, you have the complete
throw statement, and the caret in place to enter arguments:
You could see that instead of typing frequently used language constructs manually, in many cases you can type just a couple of initial characters of a template shortcut and get everything in place, properly formatted and without typos.
To apply a postfix template
Type a dot after the current expression and check the completion list for the desired templates.
If you know the shortcut of the template that you are going to apply, start typing it — this will shrink the list of suggestions.
As soon as the desired template is selected in the suggestion list, press Enter.
- If the template has editable parameters (i.e. requires user input), JetBrains Rider deploys a hot spot session in the editor and sets the input position at the first parameter. Then you can do the following:
If JetBrains Rider suggests some values for the current parameter, use Up and Down arrow keys to navigate through the list of suggested values, or just type in a desired value.
Press Tab or Enter to accept the value and move to the input position of the next parameter. If this is the last parameter, the hot spot session completes and the caret moves to the end position defined for the session.
Press Shift+Tab to move the input focus to the input position of the previous parameter.
Press Esc to exit the hot spot session. In this case, all session parameters will be initialized with default values.
List of postfix templates
Surrounds expression with invocation
Awaits expressions of 'Task' type
Surrounds expression with cast
Checks boolean expression to be 'false'
Introduces field for expression
Iterates over collection with index
Iterates over enumerable collection
Iterates over collection in reverse with index
Checks boolean expression to be 'true'
Surrounds expression with lock block
Produces instantiation expression for type
Negates boolean expression
Checks expression to be not-null
Checks expression to be null
Parenthesizes current expression
Parses string as value of some type
Introduces property for expression
Returns expression from current function
Selects expression in editor
Produces switch statement
Throws expression of 'Exception' type
Assigns current expression to some variable
Parses string as value of some type
Wraps type usage with typeof() expression
Wraps resource with using statement
Introduces variable for expression
Iterating while boolean statement is 'true'
Yields value from iterator method