knotx-handlebars-extension

Custom Knot.x Handlebars Helpers.

To build run:

• mvn clean package

To use extensions simply add knotx-handlebars-extension-x.y.z.jar to classpath together with Knot.x instance.

Helpers

• ElementHelper
• Conditions checks
  • AND
  • OR
• Math helpers
  • EqualHelper
  • GreaterEqualHelper
  • GreaterThanHelper
  • LessEqualHelper
  • LessThanHelper
• Regex helpers
  • EachSplitHelper
  • MatchHelper
• Uri helpers
  • DecodeHelper

ElementHelper

Get the n-th element from a json array.

Usage

{{element array n}}

Example

{
  locales: ["en_us", "pl_pl", "en_uk"]
}

{{element locales 2}}

Output: en_uk

Conditions checks

AND

Checks if all values are not 'falsy' (if it is false, null, 0 or empty list/array)

Usage

{{#and value1 value2 ... }}
  all values not empty
{{else}}
  some or all values empty
{{/and}}

Example

{
  "image": {
    "imageLink": "/assets/tv-set-1323122.png",
    "title": "Super TV Set with remote",
    "id": "1323122",
    "products": ["Super TV Set", "Remote"]
  }
}

{{#and image.id image.products}}
  {{#each image.products}}
     <span>{{this}}</span> 
  {{/each}}
{{else}}
  No product for image {{image.title}}
{{/and}}

Output:

<span>Super TV Set</span>
<span>Remote</span>

OR

Checks if any value is not 'falsy' (if it is false, null, 0 or empty list/array).

Usage

{{#or value1 value2 ... }}
  some value not empty
{{else}}
  all values empty
{{/or}}

Example

{
  "product": {
    "imageLink": "/assets/tv-set-1323122.png",
    "name": "Super TV",
    "technicalDescription": "OLED, 4K, WiFi",
    "producerDescription": "",
    "parts": ["Super TV Set", "Remote"]
  }
}

{{#or product.technicalDescription product.producerDescription}}
     <span>{{product.technicalDescription}}</span> 
     <span>{{product.producerDescription}}</span> 
{{else}}
  This product has no description.
{{/or}}

Output:

<span>OLED, 4K, WiFi</span>
<span></span>

Math helpers

EqualHelper

Checks if value1 and value2 are equal.

Usage

{{#eq value1 value2}}
  equal
{{else}}
  not equal
{{/eq}}

Examples

{
  "someIntA": 1,
  "someIntB": 5,
  "someDoubleA": 5.14,
  "someDoubleB": 3.14
}

{{#eq someIntA someIntB}}
  equal
{{else}}
  not equal
{{/eq}}

Output: not equal

GreaterEqualHelper

Checks if value1 is greater or equal to value2.

Usage

{{#ge value1 value2}}
  greater or equal
{{else}}
  less
{{/ge}}

Examples

{
  "someIntA": 1,
  "someIntB": 5,
  "someDoubleA": 5.14,
  "someDoubleB": 3.14
}

{{#ge someIntA someIntB}}
  greater or equal
{{else}}
  less
{{/ge}}

Output: less

{{#ge someDoubleA someDoubleB}}
  greater or equal
{{else}}
  less
{{/ge}}

Output: greater or equal

GreaterThanHelper

Checks if value1 is greater than value2. Usage

{{#gt value1 value2}}
  greater 
{{else}}
  less or equal
{{/gt}}

Examples

{
  "someIntA": 1,
  "someIntB": 5,
  "someIntC": 5
}

{{#gt someIntB someIntC}}
  greater 
{{else}}
  less or equal
{{/gt}}

Output: less or equal

LessEqualHelper

Checks if value1 is smaller or equal to value2. Usage

 {{#le value1 value2}}
         smaller or equal
 {{else}}
         greater
 {{/le}}

Examples

{
  "someIntA": 1,
  "someIntB": 5
}

{{#le someIntA someIntB}}
  less or equal 
{{else}}
  greater
{{/le}}

Output: less or equal

LessThanHelper

Checks if value1 is smaller than value2.

Usage

 {{#lt value1 value2}}
         less 
 {{else}}
         greater or equal
 {{/lt}}

Examples

{
  "someIntA": 1,
  "someIntB": 5
}

{{#lt someIntA someIntB}}
  less 
{{else}}
  greater or equal
{{/lt}}

Output: less

Regex helpers

EachSplitHelper

Splits a value using regex delimiter, and iterates over the result.

Usage

   {{each-split value delimiter_pattern}}

Examples

{
  "someString":"value1,value2,value3"
}

{{#each-split someString "\,"}}
  <td>{{this}}</td>
{{/each-split}}

Output:

  <td>value1</td>
  <td>value2</td>
  <td>value3</td>

MatchHelper

Finds a matching string using Matcher.find method.

Usage

   {{match value pattern [index] [group]}}

Examples

{
  "someString":"value1,value2,value3"
}

{{#match someString "[a-z]+[0-9]"}}

Output: value1

{{#match someString "[a-z]+[0-9]" 2}}

Output: value3

{{#match someString "[a-z]+([0-9])" 1 1}}

Output: 2

Uri helpers

DecodeHelper

Decodes given value as in URLDecoder.decode method with UTF-8 encoding.

Usage

   {{decode_uri value}}

Examples

{
  "imageData": {
    "pageUrl":"/images/?image=Some-Image-Name&id=xyz=&#x3D"
  }
}

<link rel="canonical" href="{{decode_uri imageData.pageUrl}}" />

Output: <link rel="canonical" href="/images/?image=Some-Image-Name&id=xyz%3D%3D">

EncodeHelper

Encodes given value as in URLEncoder.encode method with UTF-8 encoding.

Usage

   {{encode_uri value}}

Examples

{
  "field": "ex@mple string"
}

{{encode_uri field}}

Output: ex%40mple+string

String helpers

StringEqualsHelper

Checks if current value and given parameter are equal as Strings.

Usage

{{#string_equals value "parameter"}}
  equal
{{else}}
  not equal
{{/string_equals}}

Examples

response : {
  "statusCode": "302"
}

{{#string_equals response.statusCode "200"}}
  equal
{{else}}
  not equal
{{/string_equals}}

Output: not equal