New query condition to match all strings that starts with some other given strings

Parse/src/main/java/com/parse/OfflineQueryLogic.java

@@ -237,12 +237,24 @@ private static boolean matchesEqualConstraint(Object constraint, Object value) {
       return lhs.equals(rhs);
     }
 
-    return compare(constraint, value, new Decider() {
-      @Override
-      public boolean decide(Object constraint, Object value) {
-        return constraint.equals(value);
-      }
-    });
+    Decider decider;
+    if (isStartsWithRegex(constraint)) {
+      decider = new Decider() {
+        @Override
+        public boolean decide(Object constraint, Object value) {
+          return ((String) value).matches(((KeyConstraints)constraint).get("$regex").toString());
+        }
+      };
+    } else {
+      decider = new Decider() {
+        @Override
+        public boolean decide(Object constraint, Object value) {
+          return constraint.equals(value);
+        }
+      };
+    }
+
+    return compare(constraint, value, decider);
   }
 
   /**
@@ -348,6 +360,13 @@ private static boolean matchesAllConstraint(Object constraint, Object value) {
     }
 
     if (constraint instanceof Collection) {
+      if (isAnyValueRegexStartsWith((Collection<?>) constraint)) {
+        constraint = cleanRegexStartsWith((Collection<?>) constraint);
+        if (constraint == null) {
+          throw new IllegalArgumentException("All values in $all queries must be of starting with regex or non regex.");
+        }
+      }
+
       for (Object requiredItem : (Collection<?>) constraint) {
         if (!matchesEqualConstraint(requiredItem, value)) {
           return false;
@@ -358,6 +377,79 @@ private static boolean matchesAllConstraint(Object constraint, Object value) {
     throw new IllegalArgumentException("Constraint type not supported for $all queries.");
   }
 
+  /**
+   * Check if any of the collection constraints is a regex to match strings that starts with another
+   * string.
+   */
+  private static boolean isAnyValueRegexStartsWith(Collection<?> constraints) {
+    for (Object constraint : constraints) {
+      if (isStartsWithRegex(constraint)) {
+        return true;
+      }
+    };
+
+    return false;
+  }
+
+  /**
+   * Cleans all regex constraints. If any of the constraints is not a regex, then null is returned.
+   * All values in a $all constraint must be a starting with another string regex.
+   */
+  private static Collection<?> cleanRegexStartsWith(Collection<?> constraints) {
+    ArrayList<KeyConstraints> cleanedValues = new ArrayList<>();
+    for (Object constraint : constraints) {
+      if (!(constraint instanceof KeyConstraints)) {
+        return null;
+      }
+
+      KeyConstraints cleanedRegex = cleanRegexStartsWith((KeyConstraints) constraint);
+      if (cleanedRegex == null) {
+        return null;
+      }
+
+      cleanedValues.add(cleanedRegex);
+    }
+
+    return cleanedValues;
+  }
+
+  /**
+   * Creates a regex pattern to match a substring at the beginning of another string.
+   *
+   * If given string is not a regex to match a string at the beginning of another string, then null
+   * is returned.
+   */
+  private static KeyConstraints cleanRegexStartsWith(KeyConstraints regex) {
+    if (!isStartsWithRegex(regex)) {
+      return null;
+    }
+
+    // remove all instances of \Q and \E from the remaining text & escape single quotes
+    String literalizedString = ((String)regex.get("$regex"))
+        .replaceAll("([^\\\\])(\\\\E)", "$1")
+        .replaceAll("([^\\\\])(\\\\Q)", "$1")
+        .replaceAll("^\\\\E", "")
+        .replaceAll("^\\\\Q", "")
+        .replaceAll("([^'])'", "$1''")
+        .replaceAll("^'([^'])", "''$1");
+
+    regex.put("$regex", literalizedString + ".*");
+    return regex;
+  }
+
+  /**
+   * Check if given constraint is a regex to match strings that starts with another string.
+   */
+  private static boolean isStartsWithRegex(Object constraint) {
+    if (constraint == null || !(constraint instanceof KeyConstraints)) {
+      return false;
+    }
+
+    KeyConstraints keyConstraints = (KeyConstraints) constraint;
+    return keyConstraints.size() == 1 && keyConstraints.containsKey("$regex") &&
+        ((String)keyConstraints.get("$regex")).startsWith("^");
+  }
+
   /**
    * Matches $regex constraints.
    */

Parse/src/main/java/com/parse/ParseQuery.java

@@ -8,6 +8,8 @@
  */
 package com.parse;
 
+import android.support.annotation.NonNull;
+
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ -1673,10 +1675,6 @@ public ParseQuery<T> whereContainedIn(String key, Collection<? extends Object> v
   }
 
   /**
-   * Add a constraint to the query that requires a particular key's value match another
-   * {@code ParseQuery}.
-   * <p/>
-   * This only works on keys whose values are {@link ParseObject}s or lists of {@link ParseObject}s.
    * Add a constraint to the query that requires a particular key's value to contain every one of
    * the provided list of values.
    *
@@ -1708,6 +1706,27 @@ public ParseQuery<T> whereFullText(String key, String text) {
     return this;
   }
 
+  /**
+   * Add a constraint to the query that requires a particular key's value to contain each one of
+   * the provided list of strings entirely or just starting with given strings.
+   *
+   * @param key
+   *          The key to check. This key's value must be an array.
+   * @param values
+   *          The values that will match entirely or starting with them.
+   * @return this, so you can chain this call.
+   */
+  public ParseQuery<T> whereContainsAllStartsWith(String key, Collection<String> values) {
+    ArrayList<KeyConstraints> startsWithConstraints = new ArrayList<>();
+    for (String value : values) {
+      KeyConstraints keyConstraints = new KeyConstraints();
+      keyConstraints.put("$regex", buildStartsWithRegex(value));
+      startsWithConstraints.add(keyConstraints);
+    }
+
+    return whereContainsAll(key, startsWithConstraints);
+  }
+
   /**
    * Add a constraint to the query that requires a particular key's value match another
    * {@code ParseQuery}.
@@ -1988,7 +2007,7 @@ public ParseQuery<T> whereContains(String key, String substring) {
    * @return this, so you can chain this call.
    */
   public ParseQuery<T> whereStartsWith(String key, String prefix) {
-    String regex = "^" + Pattern.quote(prefix);
+    String regex = buildStartsWithRegex(prefix);
     whereMatches(key, regex);
     return this;
   }
@@ -2192,4 +2211,15 @@ public ParseQuery<T> setTrace(boolean shouldTrace) {
     builder.setTracingEnabled(shouldTrace);
     return this;
   }
+
+  /**
+   * Helper method to convert a string to regex for start word matching.
+   *
+   * @param prefix String to use as prefix in regex.
+   * @return The string converted as regex for start word matching.
+   */
+  @NonNull
+  private String buildStartsWithRegex(String prefix) {
+    return "^" + Pattern.quote(prefix);
+  }
 }

Parse/src/test/java/com/parse/OfflineQueryLogicTest.java

@@ -8,6 +8,8 @@
  */
 package com.parse;
 
+import android.support.annotation.NonNull;
+
 import org.json.JSONArray;
 import org.json.JSONObject;
 import org.junit.After;
@@ -23,6 +25,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.regex.Pattern;
 
 import bolts.Task;
 
@@ -419,6 +422,112 @@ public void testMatchesAll() throws Exception {
     assertFalse(matches(logic, query, object));
   }
 
+  @Test
+  public void testMatchesAllStartingWith() throws Exception {
+    ParseObject object = new ParseObject("TestObject");
+    object.put("foo", Arrays.asList("foo", "bar"));
+
+    ParseQuery.State<ParseObject> query;
+    OfflineQueryLogic logic = new OfflineQueryLogic(null);
+
+    query = new ParseQuery.State.Builder<>("TestObject")
+        .addCondition("foo", "$all",
+            Arrays.asList(
+                buildStartsWithRegexKeyConstraint("foo"),
+                buildStartsWithRegexKeyConstraint("bar")))
+        .build();
+    assertTrue(matches(logic, query, object));
+
+    query = new ParseQuery.State.Builder<>("TestObject")
+        .addCondition("foo", "$all",
+            Arrays.asList(
+                buildStartsWithRegexKeyConstraint("fo"),
+                buildStartsWithRegexKeyConstraint("b")))
+        .build();
+    assertTrue(matches(logic, query, object));
+
+    query = new ParseQuery.State.Builder<>("TestObject")
+        .addCondition("foo", "$all",
+            Arrays.asList(
+                buildStartsWithRegexKeyConstraint("foo"),
+                buildStartsWithRegexKeyConstraint("bar"),
+                buildStartsWithRegexKeyConstraint("qux")))
+        .build();
+    assertFalse(matches(logic, query, object));
+
+    // Non-existant key
+    object = new ParseObject("TestObject");
+    assertFalse(matches(logic, query, object));
+    object.put("foo", JSONObject.NULL);
+    assertFalse(matches(logic, query, object));
+
+    thrown.expect(IllegalArgumentException.class);
+    object.put("foo", "bar");
+    assertFalse(matches(logic, query, object));
+  }
+
+  @Test
+  public void testMatchesAllStartingWithParameters() throws Exception {
+    ParseObject object = new ParseObject("TestObject");
+    object.put("foo", Arrays.asList("foo", "bar"));
+
+    ParseQuery.State<ParseObject> query;
+    OfflineQueryLogic logic = new OfflineQueryLogic(null);
+
+    query = new ParseQuery.State.Builder<>("TestObject")
+        .addCondition("foo", "$all",
+            Arrays.asList(
+                buildStartsWithRegexKeyConstraint("foo"),
+                buildStartsWithRegexKeyConstraint("bar")))
+        .build();
+    assertTrue(matches(logic, query, object));
+
+    query = new ParseQuery.State.Builder<>("TestObject")
+        .addCondition("foo", "$all",
+            Arrays.asList(
+                buildStartsWithRegexKeyConstraint("fo"),
+                buildStartsWithRegex("ba"),
+                "b"))
+        .build();
+    thrown.expect(IllegalArgumentException.class);
+    assertFalse(matches(logic, query, object));
+
+    query = new ParseQuery.State.Builder<>("TestObject")
+        .addCondition("foo", "$all",
+            Arrays.asList(
+                buildStartsWithRegexKeyConstraint("fo"),
+                "b"))
+        .build();
+    thrown.expect(IllegalArgumentException.class);
+    assertFalse(matches(logic, query, object));
+  }
+
+  /**
+   * Helper method to convert a string to a key constraint to match strings that starts with given
+   * string.
+   *
+   * @param prefix String to use as prefix in regex.
+   * @return The key constraint for word matching at the beginning of a string.
+   */
+  @NonNull
+  private ParseQuery.KeyConstraints buildStartsWithRegexKeyConstraint(String prefix) {
+    ParseQuery.KeyConstraints constraint = new ParseQuery.KeyConstraints();
+    constraint.put("$regex", buildStartsWithRegex(prefix));
+    return constraint;
+  }
+
+  /**
+   * Helper method to convert a string to regex for start word matching.
+   *
+   * @param prefix String to use as prefix in regex.
+   * @return The string converted as regex for start word matching.
+   */
+  @NonNull
+  private String buildStartsWithRegex(String prefix) {
+    return "^" + Pattern.quote(prefix);
+  }
+
+
   @Test
   public void testMatchesNearSphere() throws Exception {
     ParseGeoPoint fb = new ParseGeoPoint(37.481689f, -122.154949f);

Parse/src/test/java/com/parse/ParseQueryTest.java

@@ -8,6 +8,8 @@
  */
 package com.parse;
 
+import android.support.annotation.NonNull;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -389,6 +391,25 @@ public void testWhereContainsAll() throws Exception {
     verifyCondition(query, "key", "$all", values);
   }
 
+  @Test
+  public void testWhereContainsAllStartingWith() throws Exception {
+    ParseQuery<ParseObject> query = new ParseQuery<>("Test");
+    String value = "value";
+    String valueAgain = "valueAgain";
+    List<String> values = Arrays.asList(value, valueAgain);
+
+    ParseQuery.KeyConstraints valueConverted = new ParseQuery.KeyConstraints();
+    valueConverted.put("$regex", buildStartsWithPattern(value));
+    ParseQuery.KeyConstraints valueAgainConverted = new ParseQuery.KeyConstraints();
+    valueAgainConverted.put("$regex", buildStartsWithPattern(valueAgain));
+    List<ParseQuery.KeyConstraints> valuesConverted =
+        Arrays.asList(valueConverted, valueAgainConverted);
+
+    query.whereContainsAllStartsWith("key", values);
+
+    verifyCondition(query, "key", "$all", valuesConverted);
+  }
+
   @Test
   public void testWhereNotContainedIn() throws Exception {
     ParseQuery<ParseObject> query = new ParseQuery<>("Test");
@@ -425,7 +446,7 @@ public void testWhereStartsWith() throws Exception {
     String value = "prefix";
     query.whereStartsWith("key", value);
 
-    verifyCondition(query, "key", "$regex", "^" + Pattern.quote(value));
+    verifyCondition(query, "key", "$regex", buildStartsWithPattern(value));
   }
 
   @Test
@@ -904,4 +925,9 @@ public Task<Void> then(Task<Void> task) throws Exception {
       })).cast();
     }
   }
+
+  @NonNull
+  private String buildStartsWithPattern(String value) {
+    return "^" + Pattern.quote(value);
+  }
 }