# Creating interactive examples

It is possible to define interactive examples. Examples or parts of an example can be embedded in any page. A auto-generated link enables the visitor to open the example in a playground where she can change the template, partials, input, and so on and can see the resulting output.

# Creating examples

In order to define an example, create a new markdown file in the examples-directory. The example data is defined in the frontmatter of the referenced example page. See all-features-example-raw for a complete demonstration of all features.

The following frontmatter properties are supported:

  • layout: Must always be InteractivePlaygroundLayout
  • example: Contains the example
    • template: The main Handlebars template
    • partials: An object with on property for each registered partial, the key is the partial-name, the value is the partial content
    • preparationScript: A script that is executed before compiling and running the template. Handlebars is available as global variable in this script.
    • input: The template-input as embedded YAML-object.
    • errorExpected: A boolean (default: false) that specifies that this example is expected to throw an error. By default, examples that throw an error during execution, cause the build of the whole site to fail. If you write an example that describes an error, you need to set this flag to true.

The output of the example is automatically computed using the latest release version of Handlebars.

# Embedding parts of an example.

The <ExamplePart>-component allows you to show a part of the example in the current part.

<ExamplePart examplePage="/examples/builtin-helper-each-block" show="template"/>

will result in

template
<ul class="people_list">
  {{#each people}}
    <li>{{this}}</li>
  {{/each}}
</ul>

The props for this component are:

  • examplePage: path to the example page below the src-folder
  • show: The part of the example that should be inserted into the page. Possible values are template, input, output, error, preparationScript and partial
  • name (optional): This prop is needed only when show="partial". It defines the name of the partial that should be inserted into the example.

The component is very useful if you want to embed the parts of an example into flowing text, You can insert the input JSON by using <ExamplePart examplePage="/examples/all-features" show="input" /> and the following code snippet will appear in the page:

input
{
  persons: [
    { name: "Nils", age: 20 },
    { name: "Teddy", age: 10 },
    { name: "Nelson", age: 40 }
  ]
}

Then, in order to show the reader the template you can use show="template" with the same examplePage.

template
{{>header}}
<hr/>
{{#each persons}}
{{>person person=.}}
{{/each}}

You can render a partial using for example show=partial and name=person

partial: person
The person {{loud person.name}} is {{person.age}} years old.

If you have an example with helpers, you might also want to include the preparation script:

preparationScript
Handlebars.registerHelper('loud', function (aString) {
    return aString.toUpperCase()
})

# Horizontal layout

If you want to layout two example-parts horizontally, you can use the <Flex>-component.

<Flex>
<ExamplePart examplePage="/examples/builtin-helper-each-block" show="template"/>
<ExamplePart examplePage="/examples/builtin-helper-each-block" show="input"/>
</Flex>

becomes

template
<ul class="people_list">
  {{#each people}}
    <li>{{this}}</li>
  {{/each}}
</ul>
input
{
  people: [
    "Yehuda Katz",
    "Alan Johnson",
    "Charles Jolley"
  ]
}