Ext version tested:
  • Ext 4.0 rev 6
Browser versions tested against:
  • Chrome
  • When you set both multiSelect: true and forceSelection: true, the combo box does not show existing values given to the combo box, but instead shows a red line on the box showing that "this field is required". When you remove forceSelection: true, the combo box populates correctly, but then allows users to type arbitrary text in.
Test Case:
createTermComboBox : function(config) {        
        var me = this;

        Ext.override(Ext.form.field.ComboBox, {
            getSubmitData: function() {
                var val = {};

                val[this.name] = Ext.JSON.encode(this.getSubmitValue());

                return val;
        return Ext.create("Ext.form.field.ComboBox", Ext.apply({
            columnWidth: 3/4,
            name: "Categories[Terms][]",
            value: [1,2,3,4],
            allowBlank: false,
            forceSelection: true,
            store: me.termStore,
            valueField: "Id",
            displayField: "Name",
            triggerAction: "all",
            lastQuery: "",
            multiSelect: true
        }, config));