Merge pull request #25 from marcjansen/templating

Pass values through a customizable function before replacing in template
terrestris · Sep 11, 2018 · e5ea486 · e5ea486
2 parents 9dd61cc + 5700ecd
commit e5ea486
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Showing 2 changed files with 29 additions and 5 deletions.
diff --git a/src/FeatureUtil/FeatureUtil.js b/src/FeatureUtil/FeatureUtil.js
@@ -33,11 +33,17 @@ class FeatureUtil {
    *
    * @param {ol.Feature} feature The feature to get the attributes from.
    * @param {String} template The template string to resolve.
-   * @param {String} noValueFoundText The text to apply, if the templated value
-   *                                  could not be found, default is to 'n.v.'.
+   * @param {String} [noValueFoundText] The text to apply, if the templated value
+   *   could not be found, default is to 'n.v.'.
+   * @param {Function} [valueAdjust] A method that will be called with each
+   *   key/value match, we'll use what this function returns for the actual
+   *   replacement. Optional, defaults to a function which will return the raw
+   *   value it received. This can be used for last minute adjustments before
+   *   replacing happens, e.g. to filter out falsy values or to do number
+   *   formatting and such.
    * @return {String} The resolved template string.
    */
-  static resolveAttributeTemplate(feature, template, noValueFoundText = 'n.v.') {
+  static resolveAttributeTemplate(feature, template, noValueFoundText = 'n.v.', valueAdjust = (key, val) => val) {
     let attributeTemplatePrefix = '\\{\\{';
     let attributeTemplateSuffix = '\\}\\}';
     let resolved = '';
@@ -63,7 +69,7 @@ class FeatureUtil {
           let attributeName = res.slice(2, res.length - 2);
 
           if (attributeName.toLowerCase() === key.toLowerCase()) {
-            template = template.replace(res, value);
+            template = template.replace(res, valueAdjust(key, value));
             break;
           } else {
             noMatchCnt++;

diff --git a/src/FeatureUtil/FeatureUtil.spec.js b/src/FeatureUtil/FeatureUtil.spec.js
@@ -24,7 +24,9 @@ describe('FeatureUtil', () => {
       name: 'Shinji Kagawa',
       address: 'Borsigplatz 9',
       city: 'Dortmund',
-      homepage: 'https://www.bvb.de/'
+      homepage: 'https://www.bvb.de/',
+      'exists-and-is-undefined': undefined,
+      'exists-and-is-null': null
     };
     feat = new OlFeature({
       geometry: geom
@@ -80,6 +82,22 @@ describe('FeatureUtil', () => {
         expect(got).toBe(template);
       });
 
+      it('can be configured wrt handling inexistant / falsy values', () => {
+        let template = '{{exists-and-is-undefined}}|{{exists-and-is-null}}|{{key-does-not-exist}}';
+        let got = FeatureUtil.resolveAttributeTemplate(feat, template);
+        expect(got).toBe('undefined|null|n.v.');
+        got = FeatureUtil.resolveAttributeTemplate(feat, template, '', (key, val) => {return val ? val : '';});
+        expect(got).toBe('||');
+        const mockFn = jest.fn(() => {return 'FOO';});
+        got = FeatureUtil.resolveAttributeTemplate(feat, template, '', mockFn);
+        expect(mockFn.mock.calls.length).toBe(2);
+        expect(mockFn.mock.calls[0][0]).toBe('exists-and-is-undefined');
+        expect(mockFn.mock.calls[0][1]).toBe(undefined);
+        expect(mockFn.mock.calls[1][0]).toBe('exists-and-is-null');
+        expect(mockFn.mock.calls[1][1]).toBe(null);
+        expect(got).toBe('FOO|FOO|');
+      });
+
       it('wraps an URL occurence with an <a> tag', () => {
         let template = '{{homepage}}';
         let got = FeatureUtil.resolveAttributeTemplate(feat, template);