Merge pull request #50 from adamnovak/upload-lists

Add support for lists in the web uploader

1 files changed, 121 insertions, 7 deletions

diff --git a/bh20simplewebuploader/static/main.js b/bh20simplewebuploader/static/main.js
index 96199a0..56213fa 100644
--- a/bh20simplewebuploader/static/main.js
+++ b/bh20simplewebuploader/static/main.js
@@ -34,14 +34,128 @@ let fetchAllaccessions = () => {
   fetchAPI("/api/getAllaccessions");
 };
 
+/*
+ * Make sure that only one of the manual metadata entry and metadata upload
+ * form components is *actually* a child of the form element in the DOM.
+ *
+ * Because both make use of the "required" attribute, we can't get away with
+ * just hiding the one we don't want the user to fill in. The hidden part will
+ * still have possibly empty required fields and (some) browsers will
+ * blocksubmission because of it. Moreover, the data (including file uploads)
+ * from the hidden elements will still be sent to the server, which the user
+ * may not expect.
+ */
+
+let uploadForm = document.getElementById('metadata_upload_form')
+let uploadFormSpot = document.getElementById('metadata_upload_form_spot')
+let fillForm = document.getElementById('metadata_fill_form')
+let fillFormSpot = document.getElementById('metadata_fill_form_spot') 
+
+function setUploadMode() {
+  // Make the upload form the one in use.
+  uploadFormSpot.appendChild(uploadForm)
+  // Remove the upload form from the DOM so its required-ness does not block submission.
+  fillFormSpot.removeChild(fillForm)
+}
+
+function setFillMode() {
+  // Make the fillable form the one in use
+  uploadFormSpot.removeChild(uploadForm)
+  // Remove the fillable form from the DOM so its required-ness does not block submission.
+  fillFormSpot.appendChild(fillForm)
+}
+
+function setMode() {
+  // Pick mode based on radio
+  if (document.getElementById('metadata_upload').checked) {
+    setUploadMode()
+ } else {
+    setFillMode()
+ }
+}
+
+/*
+ * Machinery for variable-length lists of input items.
+ */
+
+// Start in mode appropriate to selected form item.
+// It is important that we run this code when the page starts! The browser may
+// have set the radio button to whatever the state was on last page load,
+// instead of the default state, without raising an event, and we have to
+// handle that.
+setMode()
+
+/**
+ * Add another form field to the group this button is part of.
+ */
+function addField(e) {
+  // Find our parent field-group div
+  let fieldGroup = this.parentElement
+  
+  // Get its keypath
+  let keypath = fieldGroup.dataset.keypath
+  
+  // Find its last field child
+  let existingFields = fieldGroup.getElementsByClassName('field')
+  let templateField = existingFields[existingFields.length - 1]
+  
+  // Get its number
+  let fieldNumber = templateField.dataset.number
+  
+  // Duplicate it
+  let newField = templateField.cloneNode(true)
+  
+  // Increment the number and use the keypath and number to set IDs and cross
+  // references.
+  // TODO: Heavily dependent on the form field HTML. Maybe we want custom
+  // elements for the labeled controlsd that know how to be list items?
+  fieldNumber++
+  newField.dataset.number = fieldNumber
+  let newID = keypath + '[' + fieldNumber + ']'
+  let newControl = newField.getElementsByClassName('control')[0]
+  newControl.id = newID
+  newControl.setAttribute('name', newID)
+  let newLabel = newField.getElementsByTagName('label')[0]
+  newLabel.setAttribute('for', newID)
+  
+  // Find the minus button
+  let minusButton = fieldGroup.getElementsByClassName('remove-field')[0]
+  
+  // Put new field as a child before the minus button
+  fieldGroup.insertBefore(newField, minusButton)
+  
+  // Enable the minus button
+  minusButton.classList.remove('invisible')
+}
+
 /**
- * Show form if checked
+ * Remove the last form field from the group button is part of.
  */
-let fillFormSpot = document.getElementById('metadata_fill_form_spot');
-function displayForm() {
-  if (document.getElementById('metadata_form').checked) {
-    fillFormSpot.classList.remove("invisible");
-    return;
+function removeField(e) {
+  // Find our parent field-group div
+  let fieldGroup = this.parentElement
+  
+  // Find its field children
+  let existingFields = fieldGroup.getElementsByClassName('field')
+  
+  if (existingFields.length > 1) {
+    // There is a last field we can safely remove.
+    let lastField = existingFields[existingFields.length - 1]
+    fieldGroup.removeChild(lastField)
   }
-  fillFormSpot.classList.add("invisible");
+  
+  if (existingFields.length <= 1) {
+    // Collection auto-updates. Now there's only one element. Don't let the
+    // user remove it. If they don't want it, they can leave it empty.
+    this.classList.add('invisible')
+  }
+}
+
+// Find all the add and remove field buttons and hook up the listeners.
+for (let button of document.getElementsByClassName('add-field')) {
+  button.addEventListener('click', addField)
 }
+for (let button of document.getElementsByClassName('remove-field')) {
+  button.addEventListener('click', removeField)
+}
+