ReplaceFilter.java

package com.hubspot.jinjava.lib.filter;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.math.NumberUtils;

import com.hubspot.jinjava.doc.annotations.JinjavaDoc;
import com.hubspot.jinjava.doc.annotations.JinjavaParam;
import com.hubspot.jinjava.doc.annotations.JinjavaSnippet;
import com.hubspot.jinjava.interpret.InterpretException;
import com.hubspot.jinjava.interpret.JinjavaInterpreter;

@JinjavaDoc(
    value = "Return a copy of the value with all occurrences of a substring replaced with a new one. " +
        "The first argument is the substring that should be replaced, the second is the replacement " +
        "string. If the optional third argument count is given, only the first count occurrences are replaced",
    params = {
        @JinjavaParam(value = "s", desc = "Base string to find and replace within"),
        @JinjavaParam(value = "old", desc = "The old substring that you want to match and replace"),
        @JinjavaParam(value = "new", desc = "The new string that you replace the matched substring"),
        @JinjavaParam(value = "count", type = "number", desc = "Replace only the first N occurrences")
    },
    snippets = {
        @JinjavaSnippet(
            code = "{{ \"Hello World\"|replace(\"Hello\", \"Goodbye\") }}",
            output = "Goodbye World"),
        @JinjavaSnippet(
            code = "{{ \"aaaaargh\"|replace(\"a\", \"d'oh, \", 2) }}",
            output = "d'oh, d'oh, aaargh")
    })
public class ReplaceFilter implements Filter {

  @Override
  public String getName() {
    return "replace";
  }

  @Override
  public Object filter(Object var, JinjavaInterpreter interpreter,
      String... args) {

    if (var == null) {
      return null;
    }
    if (args.length < 2) {
      throw new InterpretException("filter " + getName() + " requires two string args");
    }

    String s = (String) var;
    String toReplace = args[0];
    String replaceWith = args[1];
    Integer count = null;

    if (args.length > 2) {
      count = NumberUtils.createInteger(args[2]);
    }

    if (count == null) {
      return StringUtils.replace(s, toReplace, replaceWith);
    }
    else {
      return StringUtils.replace(s, toReplace, replaceWith, count);
    }
  }

}