List of objects for POST in Apex REST

by Patrick Connelly posted on November 29, 2016

A while ago, someone posted on the developer boards a question about how to bulk create tasks for contacts via REST. I thought it was an interesting enough problem to cover how to do it and how to format the data correctly to use it.


Before we can bulk create tasks for a contact, we need to know how to identify those contacts. To do this, I create an unique external Id field called External_Id__c. As long as your contacts are uniquely identifiable then it doesn’t matter what field you use. For this example I have two contacts under different accounts “Andy Young” with an external Id of “ayoung” and “Edna Frank” with an external Id of “efrank”

REST Endpoint

Now that our backing data has been updated let’s look at our endpoint and break it down

Incoming Data Structure

global class TaskWrapper {
    public String subject;
    public String priority;
    public String status;
    public String externalId;

    private transient Contact con;

    public Task getTask() {
        this.con = [
            select AccountId
            from Contact
            where External_Id__c = :this.externalId

        return new Task(
            Subject = this.subject,
            Priority = this.priority,
            Status = this.status,
            WhatId = con.AccountId,
            WhoId = con.Id

This wrapper class contains all the data we need to create our task. The helper method getTask will generate a new task object that we can insert in our body.

This is not the most optimal way to do this since you will be doing SOQL inside a loop. This is just a quick example. The optimal way would be to move the contact fetching outside the loop before task creation and use that to lookup the external Id to get the contact.

The POST Method

global static List<Id> doPost(List<TaskWrapper> tasks) {
    List<Task> tasksToInsert = new List<Task>();

    for (TaskWrapper task : tasks) {

    insert tasksToInsert;

    Map<Id, Task> taskMap = new Map<Id, Task>(tasksToInsert);
    return new List<Id>(taskMap.keySet());

This method iterates through all of our inbound tasks, adds them to the list and inserts them. Again, this isn’t the way I would release it to production but it show how it can be done. The entire class be seen here.


Now that we have our endpoint, we need to throw some data at it. The data structure will start with a base element of “tasks” since that’s what the variable name is to our doPost method. Since it’s a list, the “tasks” element will be an array. Then each entry in that array is going to a TaskWrapper with all of it’s elements

    "tasks": [
            "subject": "Edna's task",
            "priority": "High",
            "status": "Not Started",
            "externalId": "efrank"
        }, {
            "subject": "Andy's task",
            "priority": "Low",
            "status": "In Progress",
            "externalId": "ayoung"

Calling the Endpoint

Of course how you call this endpoint will change depending on your implementation, but the simplest way to test it us by using cURL.

curl -X POST \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer $SESSION_ID" \
    -d @/path/to/data.json

From this we’ll get back an array of Ids to use however we want.