e8d06e0f3e
Improve templating support for block rendering for `with` expression
that has multiline code. This improves templating support to render
multiline code conditionally.
This did not work before but works now:
```
{{ with $middleLine }}
first line
second line
{{ end }}
```
106 lines
3.5 KiB
Markdown
106 lines
3.5 KiB
Markdown
# Templating
|
|
|
|
## Benefits of templating
|
|
|
|
- Generating scripts by sharing code to increase best-practice usage and maintainability.
|
|
- Creating self-contained scripts without cross-dependencies.
|
|
- Use of pipes for writing cleaner code and letting pipes do dirty work.
|
|
|
|
## Expressions
|
|
|
|
- Expressions start and end with mustaches (double brackets, `{{` and `}}`).
|
|
- E.g. `Hello {{ $name }} !`
|
|
- Syntax is close to [Go Templates ❤️](https://pkg.go.dev/text/template) that has inspired this templating language.
|
|
- Functions enables usage of expressions.
|
|
- In script definition parts of a function, see [`Function`](./collection-files.md#Function).
|
|
- When doing a call as argument values, see [`FunctionCall`](./collection-files.md#Function).
|
|
|
|
### Parameter substitution
|
|
|
|
A simple function example:
|
|
|
|
```yaml
|
|
function: EchoArgument
|
|
parameters:
|
|
- name: 'argument'
|
|
code: Hello {{ $argument }} !
|
|
```
|
|
|
|
It would print "Hello world" if it's called in a [script](./collection-files.md#script) as following:
|
|
|
|
```yaml
|
|
script: Echo script
|
|
call:
|
|
function: EchoArgument
|
|
parameters:
|
|
argument: World
|
|
```
|
|
|
|
A function can call other functions such as:
|
|
|
|
```yaml
|
|
-
|
|
function: CallerFunction
|
|
parameters:
|
|
- name: 'value'
|
|
call:
|
|
function: EchoArgument
|
|
parameters:
|
|
argument: {{ $value }}
|
|
-
|
|
function: EchoArgument
|
|
parameters:
|
|
- name: 'argument'
|
|
code: Hello {{ $argument }} !
|
|
```
|
|
|
|
### with
|
|
|
|
Skips its "block" if the variable is absent or empty. Its "block" is between `with` start (`{{ with .. }}`) and end (`{{ end }`}) expressions.
|
|
E.g. `{{ with $parameterName }} Hi, I'm a block! {{ end }}` would only output `Hi, I'm a block!` if `parameterName` has any value..
|
|
|
|
It binds its context (value of the provided parameter value) as arbitrary `.` value. It allows you to use the argument value of the given parameter when it is provided and not empty such as:
|
|
|
|
```go
|
|
{{ with $parameterName }}Parameter value is {{ . }} here {{ end }}
|
|
```
|
|
|
|
It supports multiline text inside the block. You can have something like:
|
|
|
|
```go
|
|
{{ with $argument }}
|
|
First line
|
|
Second line
|
|
{{ end }}
|
|
```
|
|
|
|
💡 Declare parameters used for `with` condition as optional. Set `optional: true` for the argument if you use it like `{{ with $argument }} .. {{ end }}`.
|
|
|
|
Example:
|
|
|
|
```yaml
|
|
function: FunctionThatOutputsConditionally
|
|
parameters:
|
|
- name: 'argument'
|
|
optional: true
|
|
code: |-
|
|
{{ with $argument }}
|
|
Value is: {{ . }}
|
|
{{ end }}
|
|
```
|
|
|
|
### Pipes
|
|
|
|
- Pipes are functions available for handling text.
|
|
- Allows stacking actions one after another also known as "chaining".
|
|
- Like [Unix pipelines](https://en.wikipedia.org/wiki/Pipeline_(Unix)), the concept is simple: each pipeline's output becomes the input of the following pipe.
|
|
- You cannot create pipes. [A dedicated compiler](./application.md#parsing-and-compiling) provides pre-defined pipes to consume in collection files.
|
|
- You can combine pipes with other expressions such as [parameter substitution](#parameter-substitution) and [with](#with) syntax.
|
|
- ❗ Pipe names must be camelCase without any space or special characters.
|
|
- **Existing pipes**
|
|
- `inlinePowerShell`: Converts a multi-lined PowerShell script to a single line.
|
|
- `escapeDoubleQuotes`: Escapes `"` characters, allows you to use them inside double quotes (`"`).
|
|
- **Example usages**
|
|
- `{{ with $code }} echo "{{ . | inlinePowerShell }}" {{ end }}`
|
|
- `{{ with $code }} echo "{{ . | inlinePowerShell | escapeDoubleQuotes }}" {{ end }}`
|