Handle non-valid dataset paths

cli/server/getDataset.js

@@ -6,7 +6,8 @@ const setUpGetDatasetHandler = ({datasetsPath}) => {
     try {
       const availableDatasets = await getAvailable.getAvailableDatasets(datasetsPath);
       const info = helpers.interpretRequest(req, datasetsPath);
-      helpers.extendDataPathsToMatchAvailable(info, availableDatasets);
+      const redirected = helpers.redirectIfDatapathMatchFound(res, info, availableDatasets);
+      if (redirected) return;
       helpers.makeFetchAddresses(info, datasetsPath, availableDatasets);
       await helpers.sendJson(res, info);
     } catch (err) {

cli/server/getDatasetHelpers.js

@@ -46,19 +46,29 @@ const interpretRequest = (req) => {
 };
 
 /**
- * Given a request, does the dataset exist?
- * In the future, if there is no exact match but a partial one we
- * should extend this. E.g. `["flu"]` -> `["flu", "h3n2", "ha", "3y"]`
- * In that case, we should utilise `res.redirect` as we do in the nextstrain.org server
- * @throws
+ * Given a request, if the dataset does not exist then either
+ * (a) redirect to an appropriate dataset if possible & return `true`
+ * (b) throw.
+ * If the dataset existed then return `false` as no redirect necessary.
  */
-const extendDataPathsToMatchAvailable = (info, availableDatasets) => {
-  const requestStrToMatch = info.parts.join("/"); // TO DO
-  /* TODO currently there must be an _exact_ match in the available datasets */
-  if (!availableDatasets.map((d) => d.request).includes(requestStrToMatch)) {
-    throw new Error(`${requestStrToMatch} not in available datasets`);
+const redirectIfDatapathMatchFound = (res, info, availableDatasets) => {
+  let matchingDatasets = availableDatasets;
+  let i;
+  const matchDatasetRequest = (d) => d.request.split("/")[i] === info.parts[i];
+  // Filter gradually by path fragment, starting from the root
+  for (i = 0; i < info.parts.length; i++) {
+    const newMatchingDatasets = matchingDatasets.filter(matchDatasetRequest);
+    if (!newMatchingDatasets.length) break;
+    matchingDatasets = newMatchingDatasets;
+  }
+  // If root fragment does cannot be matched, throw
+  if (!i) throw new Error(`${info.parts.join("/")} not in available datasets`);
+  // If best match is not equal to path requested, redirect
+  if (matchingDatasets[0].request !== info.parts.join("/")) {
+    res.redirect(`./getDataset?prefix=/${matchingDatasets[0].request}`);
+    return true;
   }
-  /* what we want to do is modify `info.parts` to match the available dataset, if possible */
+  return false;
 };
 
 /**
@@ -157,7 +167,7 @@ const findAvailableSecondTreeOptions = (currentDatasetUrl, availableDatasetUrls)
 
 module.exports = {
   interpretRequest,
-  extendDataPathsToMatchAvailable,
+  redirectIfDatapathMatchFound,
   makeFetchAddresses,
   handleError,
   sendJson,

src/components/controls/choose-dataset-select.js

@@ -7,12 +7,6 @@ import { controlsWidth } from "../../util/globals";
 
 
 class ChooseDatasetSelect extends React.Component {
-  createDataPath(dataset) {
-    let p = (this.props.choice_tree.length > 0) ? "/" : "";
-    p += this.props.choice_tree.join("/") + "/" + dataset;
-    p = p.replace(/\/+/, "/");
-    return p;
-  }
   changeDataset(newPath) {
     // 0 analytics (optional)
     analyticsControlsEvent(`change-virus-to-${newPath.replace(/\//g, "")}`);
@@ -24,22 +18,20 @@ class ChooseDatasetSelect extends React.Component {
     }
     this.props.dispatch(changePage({path: newPath}));
   }
-  getDatasetOptions() {
-    return this.props.options ?
-      this.props.options.map((opt) => ({value: opt, label: opt})) :
-      {};
-  }
   render() {
-    const datasetOptions = this.getDatasetOptions();
     return (
       <div style={{width: controlsWidth, fontSize: 14}}>
         <Select
           value={this.props.selected}
-          options={datasetOptions}
+          options={this.props.options || []}
           clearable={false}
           searchable={false}
           multi={false}
-          onChange={(opt) => {this.changeDataset(this.createDataPath(opt.value));}}
+          onChange={(opt) => {
+            if (opt.value !== this.props.selected) {
+              this.changeDataset(`/${opt.value}`);
+            }
+          }}
         />
       </div>
     );

src/components/controls/choose-dataset.js

@@ -38,39 +38,28 @@ class ChooseDataset extends React.Component {
       .replace(/\/$/, '')
       .split(":")[0];
     const displayedDataset = displayedDatasetString.split("/");
-    const options = [[]];
 
-    this.props.available.datasets.forEach((d) => {
-      const firstField = d.request.split("/")[0];
-      if (!options[0].includes(firstField)) {
-        options[0].push(firstField);
-      }
-    });
-
-
-    for (let idx=1; idx<displayedDataset.length; idx++) {
-      /* going through the fields which comprise the current dataset
-      in order to create available alternatives for each field */
-      options[idx] = [];
-      this.props.available.datasets.forEach((singleAvailableOption) => {
-        /* if the parents (and their parents etc) of this choice match,
-        then we add that as a valid option */
-        const fields = singleAvailableOption.request.split("/");
-        if (checkEqualityOfArrays(fields, displayedDataset, idx) && options[idx].indexOf(fields[idx]) === -1) {
-          options[idx].push(fields[idx]);
-        }
-      });
-    }
+    const options = displayedDataset.map((_, i) =>
+      Array.from(
+        new Set(
+          this.props.available.datasets
+            .filter((ds) => checkEqualityOfArrays(ds.request.split("/"), displayedDataset, i))
+            .map((ds) => ds.request.split("/")[i])
+        )
+      ).map((opt) => ({
+        value: displayedDataset.slice(0, i).concat(opt).join("/"),
+        label: opt
+      }))
+    );
 
     return (
       <>
         <SidebarHeader>{t("sidebar:Dataset")}</SidebarHeader>
         {options.map((option, optionIdx) => (
           <ChooseDatasetSelect
-            key={option}
+            key={displayedDataset[optionIdx]}
             dispatch={this.props.dispatch}
-            choice_tree={displayedDataset.slice(0, optionIdx)}
-            selected={displayedDataset[optionIdx]}
+            selected={displayedDataset.slice(0, optionIdx + 1).join("/")}
             options={option}
           />
         ))}