Dont allow empty values for subset

Author: bbimber

SequenceAnalysis/resources/web/SequenceAnalysis/field/TrimmingTextArea.js

@@ -19,6 +19,16 @@ Ext4.define('SequenceAnalysis.field.TrimmingTextArea', {
         this.callParent();
     },
 
+    getErrors: function(value){
+        var errors = this.callParent(arguments);
+
+        if (!this.allowBlank && this.getSubmitValue() == null) {
+            errors = errors.concat('Must enter a value');
+        }
+
+        return errors;
+    },
+
     setValue: function(val){
         if (Ext4.isString(val)) {
             val = val.split(this.delimiter);

singlecell/src/org/labkey/singlecell/pipeline/singlecell/SubsetSeurat.java

@@ -61,6 +61,11 @@ protected List<String> loadChunkFromFile() throws PipelineJobException
     {
         ToolParameterDescriptor pd = getProvider().getParameterByName("expression");
         final String val = StringUtils.trimToNull(pd.extractValue(getPipelineCtx().getJob(), getProvider(), getStepIdx()));
+        if (val == null)
+        {
+            throw new PipelineJobException("A blank subset was provided. This should have been caught upstream");
+        }
+
         final String[] values = val.split(",");
 
         List<String> ret = new ArrayList<>();