Step 2: Create A Component for User Input

Components are the building blocks of an app. They can be wired up to an Apex controller class to load your data. The component you create in this step provides a form that takes in user input about an expense, such as expense amount and date.

Click File | New | Lightning Component.
Enter form for the Name field in the New Lightning Bundle popup window. This creates a new component, form.cmp.

In the source code editor, enter this code.

The following code creates an input form that takes in user input to create an expense, which works in both a standalone app, and in Salesforce1 and Lightning Experience. For apps specific to Salesforce1 and Lightning Experience, you can use force:createRecord to open the create record page.

Note

1<aura:component implements="force:appHostable">
2  <aura:attribute name="expenses" type="Expense__c[]"/>
3  <aura:attribute name="newExpense" type="Expense__c"
4         default="{ 'sobjectType': 'Expense__c',
5                         'Name': '',
6                         'Amount__c': 0,
7                         'Client__c': '', 
8                         'Date__c': '',
9                         'Reimbursed__c': false
10                       }"/>
11  <!-- If you registered a namespace, replace the previous aura:attribute tags with the following -->
12  <!-- <aura:attribute name="expenses" type="myNamespace.Expense__c[]"/> 
13  <aura:attribute name="newExpense" type="myNamespace__Expense__c"
14               default="{ 'sobjectType': 'myNamespace__Expense__c',
15                          'Name': '',
16                          'myNamespace__Amount__c': 0,
17                          'myNamespace__Client__c': '',
18                          'myNamespace__Date__c': '',
19                          'myNamespace__Reimbursed__c': false
20                         }"/> -->
21  <!-- Attributes for Expense Counters -->
22  <aura:attribute name="total" type="Double" default="0.00" />
23  <aura:attribute name="exp" type="Double" default="0" />
24
25  <!-- Input Form using components -->
26  <div class="container">
27    <form class="slds-form--stacked">
28      <div class="slds-form-element slds-is-required">
29        <div class="slds-form-element__control">
30
31       <!-- If you registered a namespace,
32            the attributes include your namespace.
33            For example, value="{!v.newExpense.myNamespace__Amount__c}" -->
34
35          <ui:inputText aura:id="expname" label="Expense Name"
36                        class="slds-input"
37                        labelClass="slds-form-element__label"
38                        value="{!v.newExpense.Name}"
39                        required="true"/>
40         </div>
41       </div>
42       <div class="slds-form-element slds-is-required">
43         <div class="slds-form-element__control">
44           <ui:inputNumber aura:id="amount" label="Amount"
45                           class="slds-input"
46                           labelClass="slds-form-element__label"
47                           value="{!v.newExpense.Amount__c}"
48                           placeholder="20.80" required="true"/>
49          </div>
50        </div>
51        <div class="slds-form-element">
52          <div class="slds-form-element__control">
53            <ui:inputText aura:id="client" label="Client"
54                          class="slds-input"
55                          labelClass="slds-form-element__label"
56                          value="{!v.newExpense.Client__c}"
57                          placeholder="ABC Co."/>
58           </div>
59         </div>
60         <div class="slds-form-element">
61           <div class="slds-form-element__control">
62             <ui:inputDateTime aura:id="expdate" label="Expense Date"
63                               class="slds-input"
64                               labelClass="slds-form-element__label"
65                               value="{!v.newExpense.Date__c}"
66                               displayDatePicker="true"/>
67            </div>
68          </div>
69          <div class="slds-form-element">
70            <ui:inputCheckbox aura:id="reimbursed" label="Reimbursed?"
71                              class="slds-checkbox"
72                              labelClass="slds-form-element__label"
73                              value="{!v.newExpense.Reimbursed__c}"/>
74            <ui:button label="Submit" 
75                       class="slds-button slds-button--neutral"
76                       labelClass="label"
77                       press="{!c.createExpense}"/>
78           </div>
79    </form>
80  </div><!-- ./container-->
81
82  <!-- Expense Counters -->
83  <div class="container slds-p-top--medium">
84        <div class="row">
85            <div class="slds-tile ">
86                <!-- Make the counter red if total amount is more than 100 -->
87                <div class="{!v.total >= 100 
88                     ? 'slds-notify slds-notify--toast slds-theme--error slds-theme--alert-texture' 
89                     : 'slds-notify slds-notify--toast slds-theme--alert-texture'}">
90                    <p class="slds-tile__title slds-truncate">Total Expenses</p>
91                    $<ui:outputNumber class="slds-truncate" value="{!v.total}" format=".00"/>
92                </div>
93            </div>
94            <div class="slds-tile ">
95                <div class="slds-notify slds-notify--toast slds-theme--alert-texture">
96                      <p class="slds-tile__title slds-truncate">No. of Expenses</p>
97                      <ui:outputNumber class="slds-truncate" value="{!v.exp}"/>
98                  </div>
99            </div>
100        </div>
101    </div>
102          <!-- Display expense records -->
103          <div class="container slds-p-top--medium">
104              <div id="list" class="row">
105                 <aura:iteration items="{!v.expenses}" var="expense">
106
107                     <!-- If you’re using a namespace, 
108                          use the format 
109                          {!expense.myNamespace__myField__c} instead. -->
110
111                     <p>{!expense.Name}, {!expense.Client__c}, 
112                        {!expense.Amount__c}, {!expense.Date__c}, 
113                        {!expense.Reimbursed__c}</p>                     
114                </aura:iteration>
115              </div>
116          </div> 
117</aura:component>

Components provide a rich set of attributes and browser event support. Attributes are typed fields that are set on a specific instance of a component, and can be referenced using an expression syntax. All aura:attribute tags have name and type values. For more information, see Supported aura:attribute Types.

The attributes and expressions here will become clearer as you build the app. {!v.exp} evaluates the number of expenses records and {!v.total} evaluates the total amount. {!c.createExpense} represents the client-side controller action that runs when the Submit button (1) is clicked, which creates a new expense. The press event in ui:button enables you to wire up the action when the button is pressed.

Clicking the Submit button creates a new expense.

The expression {!v.expenses} wires up the component to the expenses object. var="expense" denotes the name of the variable to use for each item inside the iteration. {!expense.Client__c} represents data binding to the client field in the expense object.

The default value for newExpense of type Expense__c must be initialized with the correct fields, including sobjectType. Initializing the default value ensures that the expense is saved in the correct format.

Note

Click STYLE in the sidebar to create a new resource named form.css. Enter these CSS rule sets.
1.THIS .uiInputDateTime .datePicker-openIcon { 2 position: absolute; 3 left: 45%; 4 top: 45%; 5} 6 7.THIS .uiInputDateTime .timePicker-openIcon { 8 position: absolute; 9 left: 95%; 10 top: 70%; 11} 12 13.THIS .uiInputDefaultError li { 14 list-style: none; 15}
THIS is a keyword that adds namespacing to CSS to prevent any conflicts with another component’s styling. The .uiInputDefaultError selector styles the default error component when you add field validation in Step 5: Enable Input for New Expenses.
Note

Add the component to the app. In expenseTracker.app, add the new component to the markup.

This step adds <c:form /> to the markup. If you’re using a namespace, you can use <myNamespace:form /> instead. If you haven’t set a namespace prefix for your organization, use the default namespace c when referencing components that you’ve created.

1<aura:application extends="force:slds">  
2    <div class="slds">
3        <div class="slds-page-header">
4          <div class="slds-grid">
5            <div class="slds-col slds-has-flexi-truncate">
6              <p class="slds-text-heading--label">Expenses</p>
7              <div class="slds-grid">
8                <div class="slds-grid slds-type-focus slds-no-space">
9                  <h1 class="slds-text-heading--medium slds-truncate" title="My Expenses">My Expenses</h1>
10                </div>
11              </div>
12            </div>
13          </div>
14        </div>
15        
16        <div class="slds-col--padded slds-p-top--large">
17            <c:form />
18        </div>
19    </div>
20    </aura:application>

Save your changes and click Update Preview in the sidebar to preview your app. Alternatively, reload your browser.

In this step, the component you created doesn’t display any data since you haven’t created the Apex controller class yet.
Note

Good job! You created a component that provides an input form and view of your expenses. Next, you’ll create the logic to display your expenses.

Lightning Components Developer Guide

Step 2: Create A Component for User Input

See Also: