--- a/qiime2/qiime_dada2_denoise-single.xml	Wed Jul 17 01:53:11 2019 -0400
+++ b/qiime2/qiime_dada2_denoise-single.xml	Tue Aug 13 07:40:25 2019 -0400
@@ -8,17 +8,20 @@
 qiime dada2 denoise-single
 
 --i-demultiplexed-seqs=$idemultiplexedseqs
---p-trunc-len="$ptrunclen"
 
-#if $ptrimleft:
+#if str($ptrunclen):
+ --p-trunc-len="$ptrunclen"
+#end if
+
+#if str($ptrimleft):
  --p-trim-left=$ptrimleft
 #end if
 
-#if $pmaxee:
+#if str($pmaxee):
  --p-max-ee=$pmaxee
 #end if
 
-#if $ptruncq:
+#if str($ptruncq):
  --p-trunc-q=$ptruncq
 #end if
 
@@ -26,7 +29,7 @@
  --p-chimera-method=$pchimeramethod
 #end if
 
-#if $pminfoldparentoverabundance:
+#if str($pminfoldparentoverabundance):
  --p-min-fold-parent-over-abundance=$pminfoldparentoverabundance
 #end if
 
@@ -36,11 +39,11 @@
 #end if
 
 
-#if $pnreadslearn:
+#if str($pnreadslearn):
  --p-n-reads-learn=$pnreadslearn
 #end if
 
-#if $pnohashedfeatureids:
+#if str($pnohashedfeatureids):
  --p-no-hashed-feature-ids
 #end if
 
@@ -66,7 +69,7 @@
 		</param>
 		<param label="--p-min-fold-parent-over-abundance: NUMBER The minimum abundance of potential parents of a sequence being tested as chimeric, expressed as a fold-change versus the abundance of the sequence being tested. Values should be greater than or equal to 1 (i.e. parents should be more abundant than the sequence being tested). This parameter has no effect if chimera-method is 'none'.           [default: 1.0]" name="pminfoldparentoverabundance" optional="True" type="float" value="1.0"/>
 		<param label="--p-n-reads-learn: INTEGER The number of reads to use when training the error model. Smaller numbers will result in a shorter run time but a less reliable error model. [default: 1000000]" name="pnreadslearn" optional="True" type="integer" value="1000000"/>
-		<param label="--p-no-hashed-feature-ids: If false, the feature ids in the resulting table will be presented as hashes of the sequences defining each feature. The hash will always be the same for the same sequence so this allows feature tables to be merged across runs of this method. You should only merge tables if the exact same parameters are used for each run.                         [default: Fales]" name="pnohashedfeatureids" selected="False" type="boolean"/>
+		<param label="--p-no-hashed-feature-ids: If false, the feature ids in the resulting table will be presented as hashes of the sequences defining each feature. The hash will always be the same for the same sequence so this allows feature tables to be merged across runs of this method. You should only merge tables if the exact same parameters are used for each run.                         [default: False]" name="pnohashedfeatureids" selected="False" type="boolean"/>
 	</inputs>
 	<outputs>
 		<data format="qza" label="${tool.name} on ${on_string}: table.qza" name="otable"/>