Form Handling

When handling the data of a submitted form, you can use ObjectUtil.inject() to convert the query parameters into an object.

For example, assume we have a form as follows:

<form action="search">
      <td colspan="2">Search</td>
      <td colspan="2"><input name="text" autofocus="true" size="60"/></td>
      <td><input name="since" type="date"/></td>
      <td><input name="within" type="number"/> days</td>
      <td colspan="2"><input type="checkbox" name="hasAttachment" id="hatt"/>
        <label for="hatt">Has attachment</label></td>
      <td colspan="2" align="right"><input type="submit"></td>

Then, you can implement a class called Criteria to hold the information as follows:

class Criteria {
  String text = "";
  DateTime since;
  int within;
  bool hasAttachment = false;

Then, you can implement a request handling for the action called search in the above example as follows:

Future search(HttpConnect connect) {
  final criteria = new Criteria();
  ObjectUtil.inject(criteria, connect.request.queryParameters, silent: true);
  return searchResult(connect, criteria: criteria);

For a runnable example, you can refer to the features example.

For more complicated examples of injection, you can refer to these examples.

Custom coercion

By default, ObjectUtil.inject() will coerce the basic types, such as int, num, double, String, bool, DateTime, and Color automatically. If you need to coerce the custom types, you can implement the coercion and pass to the coerce parameter.


You can validate the values in a closure by passing it to the validate parameter when calling ObjectUtil.inject().

Notice that the validation is called after the value is coerced successfully, and before it is assigned to the target object.

Handle POST requests

Notice that HttpRequest.queryParameters includes only the parameters found in the query string. In other words, if the method of the form is POST (i.e., <form method="POST"...), you have to parse the body of the POST request. It can be done easily by use of HttpUtil.decodePostedParameters:

  HttpUtil.decodePostedParameters(request, request.queryParameters)
  .then((Map<String, String> params) {
    //handle params

If the body is a JSON string, you can use readAsJson instead. For example,

import "package:rikulo_commons/convert.dart";

Future login(HttpConnect connect) {
  return readAsJson(connect.request).then((Map<String, String> data) {
      String username = data["username"];
      String password = data["password"];