feat: by default fetch metadata and make query response readable

AFFECTS PACKAGES:
@esri/arcgis-rest-feature-service
@esri/arcgis-rest-request

ISSUES CLOSED: #375

package.json

@@ -54,7 +54,7 @@
     "shelljs": "^0.7.8",
     "slug": "^0.9.1",
     "ts-node": "^3.3.0",
-    "tslint": "^5.8.0",
+    "tslint": "^5.11.0",
     "tslint-config-prettier": "^1.6.0",
     "tslint-config-standard": "^6.0.1",
     "typedoc": "^0.12.0",

packages/arcgis-rest-feature-service/src/getFeatureService.ts

@@ -0,0 +1,31 @@
+/* Copyright (c) 2018 Environmental Systems Research Institute, Inc.
+ * Apache-2.0 */
+
+import {
+  request,
+  IRequestOptions
+} from "@esri/arcgis-rest-request";
+
+import { ILayerDefinition } from "@esri/arcgis-rest-common-types";
+
+/**
+ * Layer (Feature Service) request. See the [REST Documentation](https://developers.arcgis.com/rest/services-reference/layer-feature-service-.htm) for more information.
+ *
+ * ```js
+ * import { getFeatureService } from '@esri/arcgis-rest-feature-service';
+ *
+ * const url = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/ServiceRequest/FeatureServer/0";
+ *
+ * getFeatureService(url)
+ *   .then(response) // { name: "311", id: 0, ... }
+ * ```
+ *
+ * @param requestOptions - Options for the request.
+ * @returns A Promise that will resolve with the addFeatures response.
+ */
+export function getFeatureService(
+  url: string,
+  requestOptions: IRequestOptions
+): Promise<ILayerDefinition> {
+  return request(url, requestOptions);
+}

packages/arcgis-rest-feature-service/src/index.ts

@@ -10,3 +10,4 @@ export * from "./addAttachment";
 export * from "./updateAttachment";
 export * from "./deleteAttachments";
 export * from "./queryRelated";
+export * from "./getFeatureService";

packages/arcgis-rest-feature-service/src/query.ts

@@ -11,8 +11,12 @@ import {
   IFeatureSet,
   IFeature,
   esriUnits,
-  IExtent
+  IExtent,
+  IField,
+  ILayerDefinition
 } from "@esri/arcgis-rest-common-types";
+
+import { getFeatureService } from "./getFeatureService";
 import { ISharedQueryParams } from "./helpers";
 
 /**
@@ -88,6 +92,11 @@ export interface IQueryFeaturesRequestOptions
   returnTrueCurves?: false;
   sqlFormat?: "none" | "standard" | "native";
   returnExceededLimitFeatures?: boolean;
+  // if fields false, skip metadata check, dont massage query response
+  // if fields populated, skip metadata check, make cvds and dates readable in response
+  // if fields true, fetch metadata and make cvds and dates readable
+  // if fields missing, fetch metadata and make cvds and dates readable
+  fields?: any;
 }
 
 export interface IQueryFeaturesResponse extends IFeatureSet {
@@ -143,7 +152,7 @@ export function getFeature(
  *
  * queryFeatures({
  *   url,
- *   where: "STATE_NAME = 'Alaska"
+ *   where: "STATE_NAME = 'Alaska'"
  * }).then(result => {
  *   console.log(result.features); // array of features
  * });
@@ -155,22 +164,118 @@ export function getFeature(
 export function queryFeatures(
   requestOptions: IQueryFeaturesRequestOptions
 ): Promise<IQueryFeaturesResponse | IQueryResponse> {
-  // default to a GET request
-  const options: IQueryFeaturesRequestOptions = {
+  if (
+    typeof requestOptions.fields === "undefined" ||
+    (typeof requestOptions.fields === "boolean" && requestOptions.fields)
+  ) {
+    // ensure custom fetch and authentication are passed through
+    const metadataOptions: IRequestOptions = {
+      httpMethod: "GET",
+      authentication: requestOptions.authentication || null,
+      fetch: requestOptions.fetch || null
+    };
+    // fetch metadata to retrieve information about coded value domains
+    return getFeatureService(requestOptions.url, metadataOptions).then(
+      (metadata: ILayerDefinition) => {
+        requestOptions.fields = metadata.fields;
+        return _queryFeatures(requestOptions);
+      }
+    );
+  } else {
+    return _queryFeatures(requestOptions);
+  }
+}
+
+function _queryFeatures(
+  requestOptions: IQueryFeaturesRequestOptions
+): Promise<IQueryFeaturesResponse | IQueryResponse> {
+  const queryOptions: IQueryFeaturesRequestOptions = {
     params: {},
     httpMethod: "GET",
     url: requestOptions.url,
+    fields: false,
     ...requestOptions
   };
 
-  appendCustomParams(requestOptions, options);
+  appendCustomParams(requestOptions, queryOptions);
 
   // set default query parameters
-  if (!options.params.where) {
-    options.params.where = "1=1";
+  if (!queryOptions.params.where) {
+    queryOptions.params.where = "1=1";
   }
-  if (!options.params.outFields) {
-    options.params.outFields = "*";
+  if (!queryOptions.params.outFields) {
+    queryOptions.params.outFields = "*";
   }
-  return request(`${options.url}/query`, options);
+
+  if (!requestOptions.fields) {
+    return request(`${queryOptions.url}/query`, queryOptions);
+  } else {
+    // turn the fields array into a POJO to avoid multiple calls to Array.find()
+    const fieldsObject: any = {};
+    queryOptions.fields.forEach((field: IField) => {
+      fieldsObject[field.name] = field;
+    });
+
+    return request(`${queryOptions.url}/query`, queryOptions).then(response => {
+      response.features.forEach((feature: IFeature) => {
+        for (const key in feature.attributes) {
+          if (!feature.attributes.hasOwnProperty(key)) continue;
+          feature.attributes[key] = convertAttribute(
+            feature.attributes,
+            fieldsObject[key]
+          );
+        }
+      });
+      return response;
+    });
+  }
+}
+
+/**
+ * ripped off from https://github.com/GeoXForm/esri-to-geojson/blob/55d32955d8ef0acb26de70025539e7c7a37d838e/src/index.js#L193-L220
+ *
+ * Decodes an attributes CVD and standardizes any date fields
+ *
+ * @params {object} attribute - a single esri feature attribute
+ * @params {object} field - the field metadata describing that attribute
+ * @returns {object} outAttribute - the converted attribute
+ * @private
+ */
+
+function convertAttribute(attribute: any, field: IField) {
+  const inValue = attribute[field.name];
+  let value;
+
+  if (inValue === null) return inValue;
+
+  if (field.domain && field.domain.type === "codedValue") {
+    value = cvd(inValue, field);
+  } else if (field.type === "esriFieldTypeDate") {
+    try {
+      value = new Date(inValue).toISOString();
+    } catch (e) {
+      value = inValue;
+    }
+  } else {
+    value = inValue;
+  }
+  return value;
+}
+
+/**
+ * also ripped off from https://github.com/GeoXForm/esri-to-geojson/blob/55d32955d8ef0acb26de70025539e7c7a37d838e/src/index.js#L222-L235
+ *
+ * Looks up a value from a coded domain
+ *
+ * @params {integer} value - The original field value
+ * @params {object} field - metadata describing the attribute field
+ * @returns {string/integerfloat} - The decoded field value
+ * @private
+ */
+
+function cvd(value: any, field: IField) {
+  const domain = field.domain.codedValues.find((d: any) => {
+    return value === d.code;
+  });
+  return domain ? domain.name : value;
 }

packages/arcgis-rest-feature-service/test/features.test.ts

@@ -52,7 +52,8 @@ describe("feature", () => {
 
   it("should supply default query parameters", done => {
     const requestOptions = {
-      url: serviceUrl
+      url: serviceUrl,
+      fields: false
     };
     fetchMock.once("*", queryResponse);
     queryFeatures(requestOptions)
@@ -74,7 +75,8 @@ describe("feature", () => {
     const requestOptions = {
       url: serviceUrl,
       where: "Condition='Poor'",
-      outFields: ["FID", "Tree_ID", "Cmn_Name", "Condition"]
+      outFields: ["FID", "Tree_ID", "Cmn_Name", "Condition"],
+      fields: false
     };
     fetchMock.once("*", queryResponse);
     queryFeatures(requestOptions)

packages/arcgis-rest-request/src/utils/append-custom-params.ts

@@ -20,7 +20,8 @@ export function appendCustomParams(
       key !== "fetch" &&
       key !== "portal" &&
       key !== "maxUrlLength" &&
-      key !== "endpoint"
+      key !== "endpoint" &&
+      key !== "fields"
     ) {
       newOptions.params[key] = (oldOptions as { [key: string]: any })[key];
     }

tslint.json

@@ -10,6 +10,7 @@
     "only-arrow-functions": [false],
     "object-literal-sort-keys": false,
     "interface-name": [true, "always-prefix"],
-    "no-string-literal": false
+    "no-string-literal": false,
+    "no-console": false
   }
 }