forms - ExtJS 4 - Mark a red asterisk on an required field

Question

I have this problem where I need to add a red asterisk beside a fieldLabel when a field is marked as "required" (or allowBlank: false)

In ExtJS3, we can have this hack easily by overriding Ext.layout.FormLayout as follow:

Ext.override(Ext.layout.FormLayout, {
    getTemplateArgs: function(field) {
        var noLabelSep = !field.fieldLabel || field.hideLabel;
        var labelSep = (typeof field.labelSeparator == 'undefined' ? this.labelSeparator : field.labelSeparator);
        if (!field.allowBlank) labelSep += '<span style="color: rgb(255, 0, 0); padding-left: 2px;">*</span>';
        return {
            id: field.id,
            label: field.fieldLabel,
            labelStyle: field.labelStyle||this.labelStyle||'',
            elementStyle: this.elementStyle||'',
            labelSeparator: noLabelSep ? '' : labelSep,
            itemCls: (field.itemCls||this.container.itemCls||'') + (field.hideLabel ? ' x-hide-label' : ''),
            clearCls: field.clearCls || 'x-form-clear-left'
        };
    }
});

But this is impossible in ExtJS4. FormLayout is no longer applicable, and labels are in fact rendered by Ext.form.field.Base by using a mixins called Ext.form.Labelable.

Sadly, neither extending the Ext.form.Labelable or overriding Ext.form.Labelable is workable for me. The extended components from Ext.form.field.Base does not receive any effect from it. Even if I swapped the mixins, the templates still would not work.

So here come my solution, where I did a very harsh override over Ext.form.field.Base, and it works as follow (Check out my example)

This is for ExtJS 4.0.7 only. To use it on ExtJS 4.0.2a you need to modify the labelableRenderTpl according to the one found in 4.0.2a /src/form/Labelable.js

(function() {

    var overrides =  {
        labelableRenderTpl: [
            '<tpl if="!hideLabel && !(!fieldLabel && hideEmptyLabel)">',
                '<label id="{id}-labelEl"<tpl if="inputId"> for="{inputId}"</tpl> class="{labelCls}"',
                    '<tpl if="labelStyle"> style="{labelStyle}"</tpl>>',
                    '<tpl if="fieldLabel">{fieldLabel}{labelSeparator}</tpl>',
                    '<tpl if="!allowBlank"><span style="color:red">*</span></tpl>',
                '</label>',
            '</tpl>',
            '<div class="{baseBodyCls} {fieldBodyCls}" id="{id}-bodyEl" role="presentation">{subTplMarkup}</div>',
            '<div id="{id}-errorEl" class="{errorMsgCls}" style="display:none"></div>',
            '<div class="{clearCls}" role="presentation"><!-- --></div>',
            {
                compiled: true,
                disableFormats: true
            }
        ],

        /**
         * @protected
         * Generates the arguments for the field decorations {@link #labelableRenderTpl rendering template}.
         * @return {Object} The template arguments
         */
        getLabelableRenderData: function() {
            var me = this,
                labelAlign = me.labelAlign,
                labelCls = me.labelCls,
                labelClsExtra = me.labelClsExtra,
                labelPad = me.labelPad,
                labelStyle;

            // Calculate label styles up front rather than in the Field layout for speed; this
            // is safe because label alignment/width/pad are not expected to change.
            if (labelAlign === 'top') {
                labelStyle = 'margin-bottom:' + labelPad + 'px;';
            } else {
                labelStyle = 'margin-right:' + labelPad + 'px;';
                // Add the width for border-box browsers; will be set by the Field layout for content-box
                if (Ext.isBorderBox) {
                    labelStyle += 'width:' + me.labelWidth + 'px;';
                }
            }

            return Ext.copyTo(
                {
                    inputId: me.getInputId(),
                    fieldLabel: me.getFieldLabel(),
                    labelCls: labelClsExtra ? labelCls + ' ' + labelClsExtra : labelCls,
                    labelStyle: labelStyle + (me.labelStyle || ''),
                    subTplMarkup: me.getSubTplMarkup(),
                    allowBlank: me.allowBlank
                },
                me,
                'hideLabel,hideEmptyLabel,fieldBodyCls,baseBodyCls,errorMsgCls,clearCls,labelSeparator',
                true
            );
        }
    };


    //Both field.Base and FieldContainer are affected, so need to cater for.
    Ext.override(Ext.form.field.Base, overrides);
    Ext.override(Ext.form.FieldContainer, overrides);


})();

And so I have the nice asterisk added to all the required fields.

Question is, is there any easier way to achieve something like this? Overriding is pretty harsh, best if we can use mixins, but mixins cannot override the behavior

Note

The reason behind this is because I have customized fields that needed to be extended from the base Text, Combo, FieldContainer. Mixins in the extended field doesn't even mess with the template. They are just too stubborn. Perhaps the best way for now is by overriding the Base class... Check out the working example

Answer 1

I have a little bit shorter solution. I suggest to use form's 'beforeadd' event like this:

Ext.define('Ext.ux.form', {
    extend: 'Ext.form.Panel',
    initComponent: function() {
      this.on('beforeadd', function(me, field){
        if (!field.allowBlank)
          field.labelSeparator += '<span style="color: rgb(255, 0, 0); padding-left: 2px;">*</span>';
      });
      this.callParent(arguments);
    }
});

Here is demo