add date answer space

for now, this is just a simple date picker done via the html input type
"date". Unfortunately, that's not supported by Safari, so the rust util
now prints out a warning if it's used.

I'm not sure if there's any other reasonable option which would go
around this that's not "using a web framework" or "hacking a fallback
date picker which just consists of a couple of combo boxes".

5 files changed, 38 insertions, 2 deletions

diff --git a/example-config.dhall b/example-config.dhall
index ae12897..2dbaf30 100644
--- a/example-config.dhall
+++ b/example-config.dhall
@@ -17,5 +17,6 @@
           , "third possible answer"
           ]
     }
+  , { question = "fourth question", name = "question4", space = Answers.Date }
   ]
 }
diff --git a/site/examples/example.json b/site/examples/example.json
index fcd09d8..140fe7f 100644
--- a/site/examples/example.json
+++ b/site/examples/example.json
@@ -1 +1 @@
-{"title":"Test Survey","description":"This is a test survey.","questions":[{"question":"first question","name":"question1","space":"YesOrNo"},{"question":"second question","name":"question2","space":{"Freeform":"test"}},{"question":"third question","name":"question3","space":{"Multiple":["first possible answer","second possible answer","third possible answer"]}}],"pubkey":"age1f380w6eaeuydey65mmu88h4kqv50dda96pxlgkal78sufpnngypqnetmuu","lang":"en"}
\ No newline at end of file
+{"title":"Test Survey","description":"This is a test survey.","questions":[{"question":"first question","name":"question1","space":"YesOrNo"},{"question":"second question","name":"question2","space":{"Freeform":"test"}},{"question":"third question","name":"question3","space":{"Multiple":["first possible answer","second possible answer","third possible answer"]}},{"question":"fourth question","name":"question4","space":"Date"}],"pubkey":"age1f380w6eaeuydey65mmu88h4kqv50dda96pxlgkal78sufpnngypqnetmuu","lang":"en"}
\ No newline at end of file
diff --git a/site/index.html b/site/index.html
index 6141163..1555a21 100644
--- a/site/index.html
+++ b/site/index.html
@@ -125,6 +125,32 @@
          ];
      }
 
+     function mkDatePicker (name) {
+         let [input, label] = mkOption("date", name);
+         let errormsg = setErrormsg(
+             mkElement("div","","error"),
+             null
+         );
+         let div = appendChildren (
+             mkElement("div"),
+             [label,
+              mkElement("span", " "),
+              input,
+              errormsg]
+         );
+         return [
+             div,
+             () => {
+                 let date = input.valueAsDate;
+                 let [ret, error] = date !== null && !isNaN(date.valueOf())
+                                  ? [date.toISOString(), null]
+                                  : [null, _("Please pick a date")]
+                 setErrormsg (errormsg, error);
+                 return ret;
+             }
+         ]
+     }
+
      // essentially a case - of statement over the answerspace type.
      // since there is no validation of the config json, it may turn
      // out to be a partial function in practice.
@@ -132,6 +158,8 @@
          let space = question.space;
          if (space === "YesOrNo") {
              return mkListSpace("radio", ["yes", "no"], question.name, question.question);
+         } if (space === "Date") {
+             return mkDatePicker(question.name);
          } if ("Single" in space) {
              return mkListSpace("radio", space.Single, question.name, question.question);
          } if ("Multiple" in space) {
diff --git a/site/style.css b/site/style.css
index 08f22a6..9c4f668 100644
--- a/site/style.css
+++ b/site/style.css
@@ -22,6 +22,7 @@ li {
 
 .error {
     color: red;
+    margin-top: 0.5em;
 }
 
 textarea {
diff --git a/utils/src/main.rs b/utils/src/main.rs
index 4428ac3..cafb4f9 100644
--- a/utils/src/main.rs
+++ b/utils/src/main.rs
@@ -34,12 +34,13 @@ struct Question {
     space: AnswerSpace,
 }
 
-#[derive(Deserialize, Serialize, StaticType, Debug)]
+#[derive(Deserialize, Serialize, StaticType, Debug, PartialEq)]
 enum AnswerSpace {
     Single(Vec<String>),
     Multiple(Vec<String>),
     YesOrNo,
     Freeform(String),
+    Date,
 }
 
 #[derive(StructOpt, Debug)]
@@ -79,6 +80,11 @@ fn main () {
             std::process::exit(1);
         },
         Ok(data) => {
+            if data.questions.iter().any(|q| q.space == AnswerSpace::Date) {
+                eprintln!(">> Warning: html input type date is not supported by Safari and Internet Explorer.\n   See https://caniuse.com/input-datetime for details.");
+            }
+
+
             let json = json::to_string(&data).unwrap();
 
             // if a public key is given to encrypt the survey, ad-hoc typecheck it