Build an installation page

Installation params or iparams are parameters whose values app users can set when they install an app. These parameters are presented to the app users through the Settings page. To define iparams, render the Settings page, and use iparams:

1. Configure the iparams. During app installation, the configured iparams are displayed on an installation page. App users can enter appropriate values for the iparams and click INSTALL. The entered values are validated and saved.
2. In the app logic, use the client.iparams.get(), client.iparams.get(iparam_key), or the Request method (for secure iparams), to retrieve the iparam values. Note:To prevent exposure of sensitive iparam information, secure iparams can only be retrieved through the Request method, as part of HTTPS request headers.

For serverless apps, the configured iparams are passed as part of event payloads. The app logic can retrieve the iparams’ values from the payload.

1. From your app’s root directory, navigate to the iparam.json file.
2. Configure iparams as a JSON object with the following attributes.

{
  "contact": {
    "display_name": "Contact Details",
    "description": "Please enter the contact details",
    "type": "text",
    "required": true,
    "visible": true
  }
}

{
  "apiKey": {
    "display_name": "Api Key",
    "type": "text",
    "required": true,
    "secure": true
  }
}

{
 "Age": {
   "display_name": "Age",
   "description": "Please enter your age in years",
   "type": "text",
   "regex": {
     "age-limit": "[1-9][0-9]",
     "age-limit-error": "The age must be between 10-99"
    }
  }
}

{
  "apikey": {
    "display_name": "API key",
    "description": "Please enter your account’s API key",
    "type": "text",
    "data-bind": "product.api_key",
    "required": true
  },
  "domain": {
    "display_name": "Product Domain",
    "description": "Please enter your account’s Domain",
    "type": "text",
    "data-bind": "product.domain",
    "required": true
  }
  "url": {
    "display_name": "Product URL",
    "description": "Please enter your product URL",
    "type": "text",
    "data-bind": "product.url",
    "required": true
  }
}

A single-line text field is displayed on the installation form.

A multi-line text field is displayed.

A drop-down list from which a single option can be selected is displayed. The values specified in the options attribute of the iparams.json file are used to populate the drop-down list.

A single-line text field to enter a valid email address is displayed.

A numeric field that accepts integers upto 10 digits is displayed.

A single-line text field to enter a valid phone number is displayed.

A field to enter a valid date (or pick a date by using a date picker) is displayed.

A single-line text field to enter a valid URL is displayed.

Radio buttons along with values specified in the options attribute of the iparams.json file are displayed.

A checkbox is displayed next to the iparam.

A list, from which users can select one or more options, is displayed. The values specified in the options attribute of the iparams.json file are used to populate the list.

An input box to enter the sub-domain part of a domain URL is displayed. By default, the protocol and domain name part of the URL are displayed in the input box and are not editable. The domain name is generated based on the type_attributes.product value that is specified as part of the JSON object used to define the iparam.

A single-line text box to enter the product’s API key is displayed.

Note:The iparams of the domain and api_key types are validated when the app is installed.

A dynamic installation page or Settings page enables you to present a form in which the fields and/or values of the fields are populated dynamically, on the go, based on the app user’s input to certain fields.

When you configure iparams, you can use the events attribute to build a dynamic installation page to collect values for the installation parameters.

1. From the app’s root directory, navigate to the config/iparams.json file.
2. Include the events attribute as part of the iparam configuration. Specify an HTML event and a corresponding callback function, as a JSON object of "<event name>": "<callback function name>" pair by using the following sample format.

   {
    "firstname": {
     "display_name": "First Name",
     "description": "Please enter your business name",
     "type": "text",
     "required": true,
     "events": [
       {"change": "firstnameChange"}
     ]
    },
    "multiselect": {
     "display_name": "Other Details",
     "description": "Please select values",
     "type": "multiselect",
     "required": true,
     "options": [
       "opt1",
       "opt2",
       "opt3"
     ]
    }
   }

3. From the app’s root directory, navigate to the config directory and create the assets/iparams.js file.
4. Define the callback function by using the following sample format. Note:Ensure that the callback function’s name is the <callback function name> specified in the iparams.json file.

     function firstnameChange(arg) {
       //validation logic and subsequent action performed
       //arg is the iparam value passed to the callback function
       console.log(arg);
     }

5. To set or modify the attribute value of an iparam and add validations to an iparam, based on the input value of another iparam, use utils.set(); in the callback function definition. For more information, see iparam utility methods.
6. To retrieve the value of an iparam, based on the input value of another iparam, use utils.get(); in the callback function. For more information, see iparam utility methods.
7. To validate a value entered for an iparam or use the value entered to perform some action (such as an API call), validate the value returned, and display a success or failure message, use return; in the callback function. For more information, see return;.

When an app user enters or modifies an iparam value, the change event is triggered and the iparam value is passed to the callback function. The value is validated and subsequent actions are performed. The validation and actions are based on the logic defined in the callback function.

The FDK consists of in-built utility methods that enable you to set or modify the attribute value of an iparam, add validations to an iparam, and retrieve the value of an iparam during run-time. You can use the following methods in your callback function:

• utils.set();
• utils.get();
• return;

Enables you to set or modify the iparam attributes that are displayed in the installation page or impart further validations to the iparams.

utils.set(‘<iparam_key>’, {<attribute>: <value>});

<iparam_key> identifies the iparam that is modified or validated when the change event occurs. <attribute> specifies the iparam’s installation page attribute that is modified or the validation set for the iparam. <value> specifies the value that is set for <attribute> and must adhere to the data type of <attribute>.

For an iparam identified by <iparam_key>, <attribute> can be any of the following values.

Example 1: Sample code to set the value of the lastname iparam to the value the app user specifies for the firstname iparam.

{
  "firstname": {
    "display_name": "First Name",
    "description": "Please enter your business name",
    "type": "text",
    "required": true,
    "events": [
      {"change": "firstnameChange"}
    ]
  },
  "lastname": {
     "display_name": "Last Name",
     "description": "Please enter your last name",
     "type": "text",
     "required": false
  }
}

Example 2: Sample code to populate the multiselect iparam field with a list of options, if the app user specifies a value for the firstname iparam.

{
  "firstname": {
    "display_name": "First Name",
    "description": "Please enter your business name",
    "type": "text",
    "required": true,
    "events": [
      {"change": "firstnameChange"}
    ]
  },
  "multiselect": {
    "display_name": "Other Details",
    "description": "Please select values",
    "type": "multiselect",
    "required": true,
    "options": [
  	  "opt1",
  	  "opt2",
  	  "opt3"
    ]
  }
}

Example 1: Sample code to hide the lastname iparam from the installation page, if the app user specifies a value for the firstname iparam.

{
  "firstname": {
    "display_name": "First Name",
    "description": "Please enter your business name",
    "type": "text",
    "required": true,
    "events": [
      {"change": "firstnameChange"}
    ]
  },
  "lastname": {
    "display_name": "Last Name",
    "description": "Please enter your last name",
    "type": "text",
    "required": false
  }
}

Example 2: Sample code to display the lastname iparam in the installation page, if the app user enters a valid value for the firstname iparam and to hide the lastname iparam from the installation page, if the app user deletes the entered value.

{
  "firstname": {
    "display_name": "First Name",
    "description": "Please enter your business name",
    "type": "text",
    "required": true,
    "events": [
      {"change": "firstnameChange"}
    ]
  },
  "lastname": {
    "display_name": "Last Name",
    "description": "Please enter your last name",
    "type": "text",
    "required": false
  }
}

Sample code to modify the list of options available for the multiselect iparam and display_name to Hobbies, if the app user enters a value for the firstname iparam.

{
  "firstname": {
    "display_name": "First Name",
    "description": "Please enter your business name",
    "type": "text",
    "required": true,
    "events": [
      {"change": "firstnameChange"}
    ]
  },
  "lastname": {
    "display_name": "Last Name",
    "description": "Please enter your last name",
    "type": "text",
    "required": false
  }
  "multiselect": {
    "display_name": "Other Details",
    "description": "Please select values",
    "type": "multiselect",
    "required": true,
    "options": [
	    "opt1",
	    "opt2",
	    "opt3"
    ]
  }
}

Sample code to set a validation criteria and to modify display_name of the age iparam, if the app user enters a value for the firstname iparam. When the app user enters a value for the age iparam, if the value fails to meet the validation criteria, an error message is displayed.

{
  "firstname": {
    "display_name": "First Name",
    "description": "Please enter your business name",
    "type": "text",
    "required": true,
    "events": [
      {"change": "firstnameChange"}
    ]
  },
  "age": {
    "display_name": "Last Name",
    "description": "Please enter your last name",
    "type": "number",
    "required": false
  }
}

Enables you to identify an iparam and retrieve its value during run-time.

utils.get(‘<iparam_key>’);

<iparam_key> identifies the iparam whose value is retrieved when the change event occurs.

Returning an error message, clears the value entered for the iparam and thereby invalidates the field. Returning an empty string or not returning a value, passes the validation as a success.

return <validation criteria> ? ‘<Success Message>’: ‘<Error Message>’;

Example 1: Sample code to make an API call based on the value entered for the APIKey iparam, validate if an empty value is returned by the API call, and if so, display an error message.

{
  "APIKey": {
    "display_name": "API Key",
    "description": "Please enter your api key",
    "type": "api_key",
    "secure": true,
    "required": true,
    "type_attributes": {
      "product": "freshdesk"
    },
    "events": [
      {"change": "APIKeyChange"}
    ]
  }
}

Example 2: Sample code to invoke a third-party API based on the value entered for the acc_id iparam and validate the iparam field asynchronously by using the callback functionality.

{
  "acc_id": {
    "display_name": "Account ID",
    "description": "Please enter your Acc. ID",
    "type": "text",
    "required": true,
    "events": [{
      "change": "checkAccountID"
    }]
  }
}

To retrieve the configured iparams and to use them in the app components, use the following methods:

• client.iparams.get()
• client.iparams.get(iparam_key)

This method returns all the configured installation parameters except secure iparams.

client.iparams.get().then (
  function(data) {
    // success output
    // "data" is returned with the list of all the iparams
  },
  function(error) {
    console.log(error);
    // failure operation
  }
);

This method identifies an iparam by the iparam key specified and returns the value corresponding to the iparam. If you try to retrieve a secure iparam, an error message is displayed.

client.iparams.get("contact").then (
    function(data) {
      // success output
      // "data" is returned with the value of the "contact" attribute.
    },
    function(error) {
      console.log(error);
      // failure operation
    }
);

To test the configured installation parameters:

1. From the command prompt, navigate to the app project folder, and run the following command:

     fdk run

   If the app contains an Installation page, the following message is displayed:

     To test the installation page, visit - http://localhost:10001/custom_configs

2. Navigate to the specified location. The Installation page is displayed. Note:For an app, if a domain type iparam is configured, when testing the installation page, the domain part of the URL is updated as freshdesk.com
3. Enter appropriate values in the fields and click INSTALL.