Update Record via @RestResource class, return related SObject

Question

I'm trying to create a REST API class that will allow the following:

• POST Object ID
• Update(ObjId); ('Touching' the record, fires triggers on Salesforce)
• Find SObjects on a custom object that have been created, with Relationship__c = ObjId
• Return entire SObjects via JSON

I found some general examples here, and also read up on the describeSObjectResult class, but so far I have not been able to put all of these pieces together.

Thank you for any advice or sample code!

Answer 1

Assuming you want the original object returning together with its related children the code below should provide a starting point. Note that to call the code you will need to include authentication information. The code assumes you will pass the object id in the URL e.g.:

/services/apexrest/xyz/a00i000000AnlOC.json

The code:

@RestResource(urlMapping='/xyz/*')
global with sharing class ParentRest {
    @HttpPost
    global static SObject doPost() {
        Id parentId = extractId(RestContext.request.requestURI);
        // Fire triggers by updating
        update parentId.getSObjectType().newSObject(parentId);
        // Query parent and children in one go so all serialized
        return query(parentId);
    }
    private static SObject query(Id parentId) {
        // Query all parent fields
        DescribeSObjectResult pd = parentId.getSObjectType().getDescribe();
        String soql = 'select ' + csvs(pd.fields.getMap().keySet());
        for (ChildRelationship cr : pd.getChildRelationships()) {
            if (String.valueOf(cr.getChildSObject()).endsWithIgnoreCase('__c')) {
                // Query all child fields of each child
                DescribeSObjectResult cd = cr.getChildSObject().getDescribe();
                soql += ', (select ' + csvs(cd.fields.getMap().keySet())
                        + ' from ' + cr.getRelationshipName() + ')';
            }
        }
        soql += ' from ' + parentId.getSObjectType();
        soql += ' where Id = :parentId';
        System.debug('>>> soql=' + soql);
        return Database.query(soql);
    }
    private static String csvs(Set<String> strings) {
        return String.join(new List<String>(strings), ',');
    }
    private static Id extractId(String uri) {
        String prefix = '/xyz/';
        Integer s = uri.indexOf(prefix);
        if (s != -1) {
            s += prefix.length();
            Integer f = uri.indexOf('.', s);
            if (f == -1) {
                f = uri.length();
            }
            return (Id) uri.substring(s, f);
        }
        return null;
    }
}

An example of the sort of JSON returned:

{
  "attributes":{
    "type":"Parent__c",
    "url":"/services/data/v29.0/sobjects/Parent__c/a00i000000AnlOCAAZ"
  },
  "Name":"Parent 1",
  "LastViewedDate":"2013-11-12T21:43:10.000+0000",
  "LastReferencedDate":"2013-11-12T21:43:10.000+0000",
  "LastModifiedById":"005i0000001PYqgAAG",
  "SystemModstamp":"2013-11-12T21:43:10.000+0000",
  "CreatedById":"005i0000001PYqgAAG",
  "OwnerId":"005i0000001PYqgAAG",
  "CreatedDate":"2013-11-12T21:25:43.000+0000",
  "LastModifiedDate":"2013-11-12T21:43:10.000+0000",
  "IsDeleted":false,
  "Id":"a00i000000AnlOCAAZ",
  "Children__r":{
    "totalSize":3,
    "done":true,
    "records":[
      {
        "attributes":{
          "type":"Child__c",
          "url":"/services/data/v29.0/sobjects/Child__c/a01i0000007AfA9AAK"
        },
        "Name":"Child 2",
        "LastModifiedById":"005i0000001PYqgAAG",
        "SystemModstamp":"2013-11-12T21:26:13.000+0000",
        "CreatedById":"005i0000001PYqgAAG",
        "CreatedDate":"2013-11-12T21:26:13.000+0000",
        "LastModifiedDate":"2013-11-12T21:26:13.000+0000",
        "IsDeleted":false,
        "Id":"a01i0000007AfA9AAK",
        "Parent__c":"a00i000000AnlOCAAZ"
      },
      {
        "attributes":{
          "type":"Child__c",
          "url":"/services/data/v29.0/sobjects/Child__c/a01i0000007AfAmAAK"
        },
        "Name":"Child 3",
        "LastModifiedById":"005i0000001PYqgAAG",
        "SystemModstamp":"2013-11-12T21:26:22.000+0000",
        "CreatedById":"005i0000001PYqgAAG",
        "CreatedDate":"2013-11-12T21:26:22.000+0000",
        "LastModifiedDate":"2013-11-12T21:26:22.000+0000",
        "IsDeleted":false,
        "Id":"a01i0000007AfAmAAK",
        "Parent__c":"a00i000000AnlOCAAZ"
      },
      {
        "attributes":{
          "type":"Child__c",
          "url":"/services/data/v29.0/sobjects/Child__c/a01i0000007AfAhAAK"
        },
        "Name":"Child 1",
        "LastModifiedById":"005i0000001PYqgAAG",
        "SystemModstamp":"2013-11-12T21:25:57.000+0000",
        "CreatedById":"005i0000001PYqgAAG",
        "CreatedDate":"2013-11-12T21:25:57.000+0000",
        "LastModifiedDate":"2013-11-12T21:25:57.000+0000",
        "IsDeleted":false,
        "Id":"a01i0000007AfAhAAK",
        "Parent__c":"a00i000000AnlOCAAZ"
      }
    ]
  }
}

You can filter out fields as you build the query to simplify the response. If you want more control over the response structure, you can create your own bean classes and populate them from the query result.