Mustache flow-node
3 minute read
The following sections describe Mustache flow-node methods, parameters, and outputs.
The Mustache flow-node plugin is currently not included in the default application, but it can be installed manually with:
npm install --no-optional @axway/api-builder-plugin-fn-mustache
Method
The Mustache flow-node has a single method called Format string. It composes a string by evaluating a template using Mustache. For additional information, refer to the Mustache template language.
Parameters
The Format string method parameters are:
| Parameter | Type | Description | Configuration selection |
|---|---|---|---|
| data | any | The value to assign to the “data” variable in the template. | Any |
| template | string | The Mustache template. For example: Hi {{data.user}} |
Selector, String |
The data parameter refers to content which is provided to the template when it is evaluated at runtime. It is the selector or value that you want to pass to the Mustache template engine to provide dynamic values to the resulting string.
Providing dynamic data using a JSONPath selector
In API Builder flows, the $ is a JSONPath selector that selects data from the whole runtime context. You can also modify the selector to choose and pass specific data elements. For example, you can use $.params.username to refer to the username parameter in the flow. At design time, it is useful to have an understanding of the data that you are querying and an understanding of what the JSONPath selector will return.
The template parameter refers to the Mustache template, which is a string that contains a mixture of static and dynamic content. Both the template and data parameters are fed into the template engine at runtime. The data parameter is referred to as "data" within the template. Dynamic content is evaluated inside double curly brackets {{}}. In this example, "My name is {{data.username}}", the string "My name is" is static content and "{{data.username}}"is calculated dynamically based on the data parameter passed into the template at runtime.
Outputs
The Format string method outputs are:
| Output | Type | Description | Save output value as: |
|---|---|---|---|
| Next | string | The formatted string. | $.value |
| Error | object | The error object thrown when evaluating an invalid template. | $.error |
Examples
In this section, some examples are shown. The examples show what the Output would be for specific values for data and template parameters.
Example 1: Property “data” set to “$”
| data | template | Output |
|---|---|---|
{ params: { "username": "Joe" } } |
My name is {{data.params.username}} |
My name is Joe |
Example 2: Property “data” set to “$.param”
| data | template | Output |
|---|---|---|
{ "username": "Joe" } |
My name is {{data.username}} |
My name is Joe |
Example 3: Property “data” set to a custom object
| data | template | Output |
|---|---|---|
{ "firstname": "John", "lastname": "Doe" } |
My name is {{data.firstname}} {{data.lastname}} |
My name is John Doe |
Example 4: Greet example
This is the Greet example that comes with the newly scaffolded service.
The data property is set to “$" which has access to the config and params properties.
| data | template | Output |
|---|---|---|
{ "config": { "helloworld": { "salutation": "Howdy" }}, "params":{ "username": "John" } } |
{{data.config.helloworld.salutation}}, {{data.params.username}}! |
Howdy, John! |
Example 5: Data with array property
| data | template | Output |
|---|---|---|
{"usernames": ["John", "Jay"]} |
Hello {{data.usernames}}! |
Hello John, Jay! |
Example 6: Sections
| data | template | Output |
|---|---|---|
{ "firstname": "John", "lastname": "Doe" } |
{#data}Hi {{firstname}} {{lastname}}{/data} |
Hi John Doe |
Example 7: Array of objects
By wrapping a template in a section ({{#variable}}inner{{/variable}}), where variable is an array, the inner template content will be repeated once for each item in the array.
| data | template | Output |
|---|---|---|
[{ "item": "Oranges", "price": 10 }, { "item": "Apples": "price": 5 }]} |
My Items:{{#data}}{{item}}: £{{price}}{{/data}} |
My Items: Oranges: £10 Apples: £5 |