Hello Channels COMPLETE

Managed to get map() in there after all! Thanks Rob for the feedback that got me there

hello-nextflow/hello-channels.nf

@@ -0,0 +1,31 @@
+#!/usr/bin/env nextflow
+
+/*
+ * Use echo to print 'Hello World!' to a file
+ */
+process sayHello {
+
+    publishDir 'results', mode: 'copy'
+
+    input:
+        val greeting
+
+    output:
+        path 'output.txt'
+
+    script:
+    """
+    echo '$greeting' > output.txt
+    """
+}
+
+/*
+ * Pipeline parameters
+ */
+params.greeting = 'Holà mundo!'
+
+workflow {
+
+    // emit a greeting
+    sayHello(params.greeting)
+}

hello-nextflow/hello-workflow.nf

@@ -0,0 +1,36 @@
+#!/usr/bin/env nextflow
+
+/*
+ * Use echo to print 'Hello World!' to a file
+ */
+process sayHello {
+
+    publishDir 'results', mode: 'copy'
+
+    input:
+        val greeting
+
+    output:
+        path "${greeting}-output.txt"
+
+    script:
+    """
+    echo '$greeting' > '$greeting-output.txt'
+    """
+}
+
+/*
+ * Pipeline parameters
+ */
+params.greeting = 'greetings.csv'
+
+workflow {
+
+    // create a channel for inputs from a CSV file
+    greeting_ch = Channel.fromPath(params.greeting)
+                         .splitCsv()
+                         .map { line -> line[0] }
+
+    // emit a greeting
+    sayHello(greeting_ch)
+}

hello-nextflow/solutions/2-hello-channels/greetings-4.csv

@@ -0,0 +1,3 @@
+Hello,English
+Bonjour,French
+Holà,Spanish

hello-nextflow/solutions/2-hello-channels/hello-channels-1.nf

@@ -0,0 +1,34 @@
+#!/usr/bin/env nextflow
+
+/*
+ * Use echo to print 'Hello World!' to a file
+ */
+process sayHello {
+
+    publishDir 'results', mode: 'copy'
+
+    input:
+        val greeting
+
+    output:
+        path 'output.txt'
+
+    script:
+    """
+    echo '$greeting' > output.txt
+    """
+}
+
+/*
+ * Pipeline parameters
+ */
+params.greeting = 'Holà mundo!'
+
+workflow {
+
+    // create a channel for inputs
+    greeting_ch = Channel.of('Hello Channels!')
+
+    // emit a greeting
+    sayHello(greeting_ch)
+}

hello-nextflow/solutions/2-hello-channels/hello-channels-2.nf

@@ -0,0 +1,34 @@
+#!/usr/bin/env nextflow
+
+/*
+ * Use echo to print 'Hello World!' to a file
+ */
+process sayHello {
+
+    publishDir 'results', mode: 'copy'
+
+    input:
+        val greeting
+
+    output:
+        path "${greeting}-output.txt"
+
+    script:
+    """
+    echo '$greeting' > '$greeting-output.txt'
+    """
+}
+
+/*
+ * Pipeline parameters
+ */
+params.greeting = 'Holà mundo!'
+
+workflow {
+
+    // create a channel for inputs
+    greeting_ch = Channel.of('Hello','Bonjour','Holà')
+
+    // emit a greeting
+    sayHello(greeting_ch)
+}

hello-nextflow/solutions/2-hello-channels/hello-channels-3.nf

@@ -0,0 +1,39 @@
+#!/usr/bin/env nextflow
+
+/*
+ * Use echo to print 'Hello World!' to a file
+ */
+process sayHello {
+
+    publishDir 'results', mode: 'copy'
+
+    input:
+        val greeting
+
+    output:
+        path "${greeting}-output.txt"
+
+    script:
+    """
+    echo '$greeting' > '$greeting-output.txt'
+    """
+}
+
+/*
+ * Pipeline parameters
+ */
+params.greeting = 'Holà mundo'
+
+workflow {
+
+    greetings_array = ['Hello','Bonjour','Holà']
+
+    // create a channel for inputs
+    greeting_ch = Channel.of(greetings_array)
+                     .view { "Before flatten: $it" }
+                     .flatten()
+                     .view { "After flatten: $it" }
+
+    // emit a greeting
+    sayHello(greeting_ch)
+}

hello-nextflow/solutions/2-hello-channels/hello-channels-4.nf

@@ -0,0 +1,41 @@
+#!/usr/bin/env nextflow
+
+/*
+ * Use echo to print 'Hello World!' to a file
+ */
+process sayHello {
+
+    publishDir 'results', mode: 'copy'
+
+    input:
+        val greeting
+
+    output:
+        path "${greeting}-output.txt"
+
+    script:
+    """
+    echo '$greeting' > '$greeting-output.txt'
+    """
+}
+
+/*
+ * Pipeline parameters
+ */
+params.greeting = 'greetings.csv'
+
+workflow {
+
+    greetings_array = ['Hello','Bonjour','Holà']
+
+    // create a channel for inputs from a CSV file
+    greeting_ch = Channel.fromPath(params.greeting)
+                         .view { "Before splitCsv: $it" }
+                         .splitCsv()
+                         .view { "After splitCsv: $it" }
+                         .map { line -> line[0] }
+                         .view { "After map: $it" }
+
+    // emit a greeting
+    sayHello(greeting_ch)
+}