Add special handling of the content type HTTP header

runtime/bin/http.dart

Index: runtime/bin/http.dart
diff --git a/runtime/bin/http.dart b/runtime/bin/http.dart
index b0d01d3d03dfc806e0627a2bfe3b9c0b455fa6bd..8679c01edf840a84b1e2cb3582592dc67c86dbd6 100644
--- a/runtime/bin/http.dart
+++ b/runtime/bin/http.dart
@@ -299,6 +299,80 @@ interface HttpHeaders default _HttpHeaders {
    * connection.
    */
   int port;
+
+  /**
+   * Gets and sets the content type.
+   */
+  ContentType contentType;

[Anders Johnsen, 2012/05/21 07:37:30]

IMO, this is a good way of exposing this.

[Søren Gjesse, 2012/05/21 11:11:06]

Thanks!

+}
+
+
+/**
+ * Representation of a header value in the form:
+ *
+ *   [:value; parameter1=value1; parameter2=value2:]
+ */
+interface HeaderValue default _HeaderValue {

[Anders Johnsen, 2012/05/21 07:37:30]

The name HeaderValue confuses me. It sounds as it should be what you get from
all HttpHeader's get methods, not something that is only associated to
ContentType. Maybe rename to ContentTypeValue?

[Mads Ager (google), 2012/05/21 07:40:39]

Should we expose this interface? At this point only ContentType extends it and
it has getters/setters for the value and parameter. It is not clear to me why
this interface is useful to the user?

[Søren Gjesse, 2012/05/21 11:11:06]

ContentType extend HeaderValue. It should be possible to use an instance of
HeaderValue to set any header. I will describe this more carefuly.

[Søren Gjesse, 2012/05/21 11:11:06]

Currently this interface is extended by ContentType. However a lot of the HTTP
headers are on this form, and HeaderValue is useful for handling headers for
which no special treatment is provided. E.g. the Accept header can have a value
like this:

  text/*;q=0.3, text/plain;q=0.7, text/html

HttpClientRequest request;

var v = new HeaderValue();
v.value = "text/*";
v.parameters["q"] = "0.3"
request.headers.add(HttpHeaders.ACCEPT, v);
v = new HeaderValue();
v.value = "text/plain";
v.parameters["q"] = "0.7"
request.headers.add(HttpHeaders.ACCEPT, v);
request.headers.add(HttpHeaders.ACCEPT, "text/html");

Likewise for parsing

HttpRequest request;
var l = request.headers[HttpHeaders.ACCEPT];
l.forEach((value) {
  HeaderValue v = new HeaderValue.fromString(value);
  ... v.value ...
  ... v.parameters ...
});

I will update the the documentation to describe this.

+  /**
+   * Creates a new header value object setting the value.
+   */
+  HeaderValue([String value]);
+
+  /**
+   * Creates a new header value object from parsing a header value.

[Mads Ager (google), 2012/05/21 07:40:39]

What is the format of the input string? Does it contain the initial "name=" part
of is it only the "value; parameter1=value1; ..." part?

Maybe explicitly give an example input string?

[Søren Gjesse, 2012/05/21 11:11:06]

Added example to interface description.

+   */
+  HeaderValue.fromString(String value);
+
+  /**
+   * Gets and sets the header value.
+   */
+  String value;

[Anders Johnsen, 2012/05/21 07:37:30]

Have a toString that maps to the full content?

[Søren Gjesse, 2012/05/21 11:11:06]

toString was already there. Documentation added.

+
+  /**
+   * Gets the map of parameters.
+   */
+  Map<String, String> get parameters();
+}
+
+
+/**
+ * Representation of a content type.
+ */
+interface ContentType extends HeaderValue default _ContentType {

[Anders Johnsen, 2012/05/21 07:37:30]

Here, I think we should have a toString as well.

[Søren Gjesse, 2012/05/21 11:11:06]

toString is now documented in the HeaderValue interface.

+  /**
+   * Creates a new content type object setting the primary type and
+   * sub type. If either is not passed their values will be the empty
+   * string.
+   */
+  ContentType([String primaryType, String subType]);
+
+  /**
+   * Creates a new content type object from parsing a Content-Type
+   * header value. As primary type, sub type and parameter names and

[Mads Ager (google), 2012/05/21 07:40:39]

Maybe give a concrete example of a Content-Type header value string?

[Søren Gjesse, 2012/05/21 11:11:06]

Done.

+   * values are not case sensitive all these values will be converted
+   * to lower case.
+   */
+  ContentType.fromString(String value);
+
+  /**
+   * Gets and sets the content type in the form "primaryType/subType".
+   */
+  String value;
+
+  /**
+   * Gets and sets the primary type.
+   */
+  String primaryType;
+
+  /**
+   * Gets and sets the sub type.
+   */
+  String subType;
+
+  /**
+   * Gets and sets the character set.

[Mads Ager (google), 2012/05/21 07:40:39]

Can we specify the valid values in the interface? Or at least add a link to the
http 1.1 docs on the character sets? Should we have a charset type? That might
be the easiest way to communicate the possible charsets.

[Søren Gjesse, 2012/05/21 11:11:06]

This is not really possible.

+   */
+  String charset;
 }