Merge pull request #393 from tiritea/master

Add substring-before() and substring-after() XPath functions
getodk · Jan 2, 2019 · aa47832 · aa47832
2 parents 23ceaae + 3169603
commit aa47832
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diff --git a/src/org/javarosa/xpath/expr/XPathFuncExpr.java b/src/org/javarosa/xpath/expr/XPathFuncExpr.java
@@ -344,6 +344,18 @@ public Object eval (DataInstance model, EvaluationContext evalContext) {
             }
         } else if (name.equals("substr") && (args.length == 2 || args.length == 3)) {
             return substring(argVals[0], argVals[1], args.length == 3 ? argVals[2] : null);
+        } else if (name.equals("substring-before") && args.length == 2) {
+            String str = toString(argVals[0]);
+            String substr = toString(argVals[1]);
+            int pos = str.indexOf(substr);
+            // XPath reference states that we should return the empty string when we don't find the substring
+            return pos >= 0 ? str.substring(0, pos) : "";
+        } else if (name.equals("substring-after") && args.length == 2) {
+            String str = toString(argVals[0]);
+            String substr = toString(argVals[1]);
+            int pos = str.indexOf(substr);
+            // XPath reference states that we should return the empty string when we don't find the substring
+            return pos >= 0 ? str.substring(pos + substr.length()) : "";
         } else if (name.equals("contains") && args.length == 2) {
             return toString(argVals[0]).contains(toString(argVals[1]));
         } else if (name.equals("starts-with") && args.length == 2) {

diff --git a/test/org/javarosa/xpath/test/XPathEvalTest.java b/test/org/javarosa/xpath/test/XPathEvalTest.java
@@ -250,6 +250,16 @@ public void doTests () {
         testEval("substr('hello',1,4)", "ell");
         testEval("substr('hello',-2)", "lo");
         testEval("substr('hello',0,-1)", "hell");
+        testEval("substring-before('hello','l')", "he");
+        testEval("substring-before('hello','q')", "");
+        testEval("substring-before('hello','')", "");
+        testEval("substring-before('','')", "");
+        testEval("substring-before('','q')", "");
+        testEval("substring-after('hello','l')", "lo");
+        testEval("substring-after('hello','q')", "");
+        testEval("substring-after('hello','')", "hello");
+        testEval("substring-after('','')", "");
+        testEval("substring-after('','q')", "");
         testEval("contains('a', 'a')",      true);
         testEval("contains('a', 'b')",      false);
         testEval("contains('abc', 'b')",    true);