This is a small library that can be used in Salesforce to update & deploy changes to custom metadata types (CMDT) from Apex and Flow.
The included lwc custom-metadata-table is designed to work specifically with CMDT records. It includes 3 properties that you can set within Flow or your own lightning component
records- an instance ofList<SObject>in Apex, or a 'record collection' within Flow, containing the CMDT records to display within the table.- All of the 
SObjectrecords must be of the sameSObject Type. - You can create or query the list of CMDT records - see README for details on how to create CMDT records in Apex and Flow.
 - When creating new CMDT records, you must populate both fields 
DeveloperNameandMasterLabelin order to successfully deploy the new records. 
- All of the 
 fieldToDisplay- a comma-separated list of field API names that should be shown in the table.- When the parameter 
enableEditing == true, all fields, exceptDeveloperNameand lookup fields, will be editable within the table. This is done via thelightning-datatable's inline-editing functionality 
- When the parameter 
 enableEditing- Boolean value to control if CMDT records are displayed in read-only mode (enableEditing == false) or with inline-editing enabled (enableEditing == true)
Users can use this component to edit the CMDT records and simply click 'Save' to deploy any changes to the current org. The component then displays a loading-spinner while the deployment runs - it continues to check the deployment status until the deployment is done (either it suceeds or it fails).
In order to check the deployment's status, the component makes callouts to the REST API in your org - this is necessary because the deployment status cannot be checked natively within Apex. Depending on your org, some additional configuration may be needed to allow the callouts:
- Org uses "My Domain": no additional changes should be required in your org - orgs with the "My Domain" feature configured can already make callouts to the same org without any additional configuration
 - Org does not use "My Domain": in your org, configure a Remote Site Setting - the URL of the remote site setting should be the URL of your Salesforce org
 
This screenshot shows an example of the table, using the include CMDT object CustomMetadataDeployTest__mdt
Within Flow, you can leverage the lwc custom-metadata-table in 2 steps
- 
Query the list of CMDT records to display and store them in a record collection variable
 - 
Add a screen to display the
custom-metadata-tablecomponent - here, you will provide the CMDT record collection variable and a comma-separated list of fields to display 
Deploying CMDT changes from Flow consists of 2 actions
- Create a New Custom Metadata Record (
FlowCustomMetadataCreator.newInstance(List<FlowInput> inputs)) - this action creates a new in-memory instance of the specified CMDT object. This is needed because Salesforce does not allow you to create a new CMDT record directly in Flow. Each input has 3 attributes, and theSObjectinstance of the new CMDT record is returned.String customMetadataTypeName- The API name of the CMDT objectString masterLabel- The value to use as the new CMDT record's labelString developerName- The value to use as the new CMDT record's unique name
 
- Update your CMDT records using Flow - Once you have either created a new CMDT record, or queried for existing CMDT records, you can use standard Flow assignments & loops to make changes to the CMDT records.
 
- Deploy Changes to Custom Metadata Records (
CustomMetadataSaver.deploy(List<SObject> cmdtRecords)- this action will asynchronously deploy any pending changes made to CMDT records. Simply pass in your collection of new and/or updated CMDT records, and the Apex action will deploy the changes.List<SObject> cmdtRecords- The collection of custom metadata records to deploy
 
Since Apex can already update custom metadata records (it just can't save the changes using DML statements), it's fairly straightforward process to deploy the changes from Apex.
- First, create or query for the CMDT records you want to update
 - Next, set any desired fields on your CMDT records
 - Finally, call the method 
CustomMetadataSaver.deploy(List<SObject> cmdtRecords)to deploy your records 
    // Create new CMDT record (or you can query existing records)
    CustomMetadataDeployTest__mdt myExampleCMDT = new CustomMetadataDeployTest__mdt();
    myExampleCMDT.MasterLabel = 'My CMDT Record';
    myExampleCMDT.DeveloperName = 'My_CMDT_Record';
    myExampleCMDT.ExampleTextField__c = 'Some value';
    // Add the new CMDT record to a list
    List<CustomMetadataDeployTest__mdt> records = new List<CustomMetadataDeployTest__mdt>{myExampleCMDT};
    // Finally, deploy your changes
    CustomMetadataSaver.deploy(records);
    // Bonus, get the deployment job IDs if you want to monitor them
    List<Id> deploymentJobIds = CustomMetadataSaver.getDeploymentJobIds();When deploying metadata through Apex, Salesforce provides the ability to create a callback class using Metadata.DeployCallback.
Out-of-the-box, this CustomMetadataSaver uses a private inner class, CustomMetadataSaver.DefaultDeployCallback, when deploying CMDT records. It provides 2 options:
sendEmailOnError- sends an email to the current user when there are 1 or more deployment errorssendEmailOnSuccess- sends an email to the current user when there are no deployment errors
To use your own custom Apex class for the callback, first create your class similar to this example
public class ExampleCallback implements Metadata.DeployCallback {
    public void handleResult(Metadata.DeployResult result, Metadata.DeployCallbackContext context) {
        System.debug('ExampleCallback is running!');
    }
}Within Apex, you can then pass an instance of your class as a parameter to the method CustomMetadataSaver.deploy()
// Create your CMDT records
List<CustomMetadataDeployTest__mdt> myCMDTRecords = new List<CustomMetadataDeployTest__mdt>();
CustomMetadataDeployTest__mdt myExampleCMDT = new CustomMetadataDeployTest__mdt();
myExampleCMDT.MasterLabel = 'My CMDT Record';
myExampleCMDT.DeveloperName = 'My_CMDT_Record';
myExampleCMDT.ExampleTextField__c = 'Some value';
myCMDTRecords.add(myExampleCMDT);
// Create an instance of your custom callback class
ExampleCallback myCustomCallback = new ExampleCallback();
// Pass the CMDT records and your custom callback to CustomMetadataSaver
CustomMetadataSaver.deploy(myCMDTRecords, myCustomCallback);Within Flow, you can also specify a custom callback class by specifying the Apex class name within the deploy action







