Powershell encode JSON array in URL for RestMethod - powershell

Question

I am using Knack to solve a business process issue, however to ensure it's success I need to run a daily script to sync the data between Knack and our HR system.
Knack uses a REST API and I want to apply a filter to the GET call so that I don't have to populate a local table in order to compare the data.
Knack requires a JSON array like the example below to be encoded in the URL in order to filter the results returned. The example shows how to do this in Javascript but I cannot work out how to do this in Powershell would anyone be able to assist?
// Request route
var api_url = 'https://api.knack.com/v1/objects/object_1/records';
// Prepare filters
var filters = {
'match': 'or',
'rules': [
{
'field':'field_1',
'operator':'is',
'value':'Dodgit'
},
{
'field':'field_1',
'operator':'is blank'
}
]
};
// Add filters to route
api_url += '?filters=' + encodeURIComponent(JSON.stringify(filters));

Answer 1

You can do the following:
$api_url = 'https://api.knack.com/v1/objects/object_1/records'
$filters = #'
{
'match': 'or',
'rules': [
{
'field':'field_1',
'operator':'is',
'value':'Dodgit'
},
{
'field':'field_1',
'operator':'is blank'
}
]
}
'#
$CompressedFilters = $filters | ConvertFrom-Json | ConvertTo-Json -Depth 10 -Compress
$encodedUri = "{0}?filters={1}" -f $api_url,[System.Web.HttpUtility]::UrlEncode($CompressedFilters)
Explanation:
$filters is defined as a here-string. $filters is piped into ConvertFrom-Json and then to ConvertTo-Json in order to compress the JSON data easily. However, that does swap single quotes for double quotes.
UrlEncode() from the System.Web.HttpUtility .NET class encodes special characters in URLs.
-f is the string format operator. This helps to build your URI string. The final URI is stored in $encodedUri.
NOTE: The [System.Web.HttpUtility]::UrlEncode encodes special characters with lowercase hex characters. If your system requires uppercase hex characters, then use [System.Net.WebUtility]::UrlEncode instead.