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W3C mobileOK Basic Tests 1.0
W3C Recommendation 08 December 2008
- This version:
- https://www.w3.org/TR/2008/REC-mobileOK-basic10-tests-20081208/
- Latest version:
- https://www.w3.org/TR/mobileOK-basic10-tests/
- Previous version:
- https://www.w3.org/TR/2008/PR-mobileOK-basic10-tests-20081103/
- Editors:
- Sean Owen, Google
- Jo Rabin, dotMobi (and before at Segala)
Please refer to the errata for this document, which may include some normative corrections.
See also translations.
Copyright © 2008 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply.
Abstract
This document defines the tests that provide the basis for making a claim of W3C® mobileOK™ Basic conformance and are based on W3C Mobile Web Best Practices [Best Practices]. The details of how to claim mobileOK conformance will be described separately. Providers of content which passes the tests have taken some steps to provide a functional user experience for users of basic mobile devices whose capabilities at least match those of the Default Delivery Context (DDC).
mobileOK Basic primarily assesses basic usability, efficiency and interoperability. It does not address the important goal of assessing whether users of more advanced devices enjoy a richer user experience than is possible using the DDC.
Status of this Document
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.
This document was developed by the Mobile Web Best Practices Working Group as part of the Mobile Web Initiative.
Please see the Working Group's implementation report. A complete list of the editorial changes since the previous version of this document is available.
Please send comments about this document to public-bpwg-comments@w3.org (with public archive).
This document defines machine-verifiable tests, based on the W3C Mobile Web Best Practices [Best Practices]. Although content authors are not expected to use this document directly, participants of the Working Group expect tools that implement the tests defined in this document to greatly improve the authoring of content that addresses the browsing experience of users on a broad range of devices.
This document has been reviewed by W3C Members, by software developers, and by other W3C groups and interested parties, and is endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
Table of Contents
1 Introduction
1.1 Scope
1.1.1 Relationship to Best Practices
1.1.2 Out of Scope
1.1.3 Beyond mobileOK
1.2 Applicability
1.3 Claiming mobileOK conformance
2 Conformance
2.1 Use of Terms must, should etc.
2.2 Validity of the Tests
2.3 Testing Outcomes
2.4 Conduct of Tests
2.4.1 Order of Tests
2.4.2 HTTPS
2.4.3 HTTP Request
2.4.4 HTTP Response
2.4.5 Meta http-equiv Elements
2.4.6 CSS Style
2.4.7 Included Resources
2.4.8 Linked Resources
2.4.9 Validity
2.4.10 White Space
3 mobileOK Basic Tests
3.1
AUTO_REFRESH and REDIRECTION
3.2
CACHING
3.3
CHARACTER_ENCODING_SUPPORT
and CHARACTER_ENCODING_USE
3.4
CONTENT_FORMAT_SUPPORT and
VALID_MARKUP
3.5
DEFAULT_INPUT_MODE
3.6
EXTERNAL_RESOURCES
3.7
GRAPHICS_FOR_SPACING
3.8
IMAGE_MAPS
3.9
IMAGES_RESIZING and IMAGES_SPECIFY_SIZE
3.10
LINK_TARGET_FORMAT
3.11
MEASURES
3.12
MINIMIZE
3.13
NO_FRAMES
3.14
NON-TEXT_ALTERNATIVES
3.15
OBJECTS_OR_SCRIPT
3.15.1 Object Element Processing Rule
3.16
PAGE_SIZE_LIMIT
3.17
PAGE_TITLE
3.18
POP_UPS
3.19
PROVIDE_DEFAULTS
3.20
STYLE_SHEETS_SUPPORT
3.21
STYLE_SHEETS_USE
3.22
TABLES_ALTERNATIVES
3.23
TABLES_LAYOUT
3.24
TABLES_NESTED
Appendices
A Acknowledgments (Non-Normative)
B References (Non-Normative)
C Relationship between Best Practices and mobileOK Tests (Non-Normative)
1 Introduction
mobileOK Basic is a scheme for assessing whether Web resources (Web content) can be delivered in a manner that is conformant with Mobile Web Best Practices [Best Practices] to a simple and largely hypothetical mobile user agent, the Default Delivery Context.
This document describes W3C mobileOK Basic tests for delivered content, and describes how to emulate the DDC when requesting that content.
The intention of mobileOK is to help catalyze development of Web content that provides a functional user experience in a mobile context. It is not a test for browsers, user agents or mobile devices, and is not intended to imply anything about the way these should behave.
mobileOK does not imply endorsement or suitability of content. For example, it must not be assumed that a claim that a resource is mobileOK conformant implies that it is of higher informational value, is more reliable, more trustworthy or is more appropriate for children than any other resource.
1.1 Scope
1.1.1 Relationship to Best Practices
mobileOK Basic tests are based on a limited subset of the Mobile Web Best Practices. Their outcome is machine-verifiable, hence claims of mobileOK Basic conformance are easy to check.
Content passing the tests demonstrates that the content provider has taken basic steps to provide a functional experience for mobile users.
mobileOK Basic conformance should be considered only a first step towards building a harmonized experience for mobile users. Conformance merely demonstrates that a basic experience is available, interoperable with a large number of mobile devices. mobileOK Basic conformance says nothing about richer, more sophisticated, experiences that may be available, nor does it say anything about whether other guidelines for development of Web content (such as [WCAG 1.0]) have been followed.
1.1.2 Out of Scope
Some Best Practices, like TESTING, are advisable but do not meaningfully translate into concrete tests.
The tests assess whether the content can be provided in a way that achieves basic usability, efficiency, and interoperability with mobile devices. The tests should not be understood to assess thoroughly whether the content has been well-designed for mobile devices.
1.1.3 Beyond mobileOK
The Best Practices, and hence the tests, are not promoted as guidance for achieving the optimal user experience. The capabilities of many devices exceed those defined by the DDC. It will often be possible, and generally desirable, to provide an experience designed to take advantage of the extra capabilities.
Content providers should provide an experience that is mobileOK Basic conformant to ensure a basic level of interoperability. Providers are encouraged to provide enhanced experiences as well when these are appropriate to their application and devices that are accessing them.
1.2 Applicability
The tests apply to a URI. Passing the tests means that when accessed as described in 2.4.3 HTTP Request, resolving a URI will result in mobileOK Basic conformant content that is delivered in a mobileOK Basic conformant manner.
That is, the tests do not apply solely to content or document instances. Many Best Practices relate not just to the document (e.g. VALID_MARKUP), but to how it is delivered to a mobile device (e.g. CACHING).
mobileOK Basic says nothing about what may be delivered to non-mobile devices.
1.3 Claiming mobileOK conformance
A standard mechanism will be defined that allows content providers to claim that a URI or group of URIs, such as a Web site, conforms to mobileOK Basic. It will be possible to make claims in a machine-processable form. It will also be possible to notify end users of the presence of the claim by means of a human-readable mark.
The details of the mechanism for claiming mobileOK conformance will be described separately.
2 Conformance
2.1 Use of Terms must, should etc.
Where terms are used with the meanings defined in [RFC 2119] they are highlighted in the text e.g. must.
2.2 Validity of the Tests
mobileOK tests are only meaningful when the URI under test resolves to HTML content delivered over HTTP.
2.3 Testing Outcomes
Individual tests may result in PASS or FAIL. PASS is required from all tests in order to claim mobileOK Basic conformance. In any test, PASS is achieved if and only if there are no FAILs. No specific PASS outcome is defined for any test.
Tests may also generate a number of informative warnings which do not affect whether a test has PASSed or not. A warning may indicate that it could not be conclusively determined whether the content under test conforms to a Best Practice (and thus does not FAIL), or may indicate that the content under test is close to violating a Best Practice.
2.4 Conduct of Tests
2.4.1 Order of Tests
mobileOK Basic does not prescribe the order in which tests are to be carried out as they may be executed independently. Some tests have been designed to assess aspects of the content that are disallowed by other tests; this is deliberate and is intended to allow testing environments to provide as much information as possible.
For example the test for 3.21
STYLE_SHEETS_USE
points out that
style sheets should be used in preference to markup elements such as
center, even though the center element is also
disallowed by the test for 3.4
CONTENT_FORMAT_SUPPORT and
VALID_MARKUP.
Creators of implementations of the tests described in this document are encouraged to provide as much information as possible to users of their implementations. Where possible they should not stop on FAIL and specifically they should:
Provide information about the cause of warning or failure (each warn and FAIL is individually identified);
Continue individual tests as far as is possible;
Carry out as many tests as is reasonable.
2.4.2 HTTPS
Note:
Arbitrary root certificates (including self-signed certificates) should be regarded as trusted.
When resolving a URI, if the URI has the scheme https:
If the certificate presented does not match the requested URI, FAIL
If the certificate has expired, or is not yet valid, warn
If certificate validation otherwise fails, FAIL
2.4.3 HTTP Request
The following HTTP request headers inform the server that it should deliver content that is compatible with the Default Delivery Context.
Use the HTTP
GETmethod when making requests, except for 3.10 LINK_TARGET_FORMAT where theHEADmethod may be used (See 2.4.8 Linked Resources for a discussion of thePOSTmethod).Include a
User-Agentheader which starts exactly as follows (indicating the Default Delivery Context, and which may be extended in accordance with [RFC 2616] Section 14.43, User-Agent Header) :User-Agent: W3C-mobileOK/DDC-1.0 (see https://www.w3.org/2006/07/mobileok-ddc)
Include an
Acceptheader indicating that Internet media types understood by the Default Delivery Context are accepted by sending exactly this header:Accept: application/xhtml+xml,text/html;q=0.1,application/vnd.wap.xhtml+xml;q=0.1,text/css,image/jpeg,image/gif
Include an
Accept-Charsetheader indicating that only UTF-8 is accepted by sending exactly this header:Accept-Charset: UTF-8
Do not include cookie related headers.
Include authentication information if required (see 2.4.4 HTTP Response). Once authentication information has been included in a request, subsequent requests for the same realm must include authentication information as described in Section 2 and under "domain" in Section 3.2.1 of [RFC 2617].
Implementations must support URIs with both
httpandhttpsscheme components.Note:
As noted under 2.4.7 Included Resources and 2.4.8 Linked Resources the URIs that are relevant to mobileOK are those that, when represented in an absolute form, have either the
httpor thehttpsscheme. Requests should not be made for URIs with schemes other thanhttpandhttps.
2.4.4 HTTP Response
Note:
Implementations must support basic and digest authentication.
Note:
Below, note that a 404 or 5xx response for the resource under test does not result in a FAIL in order to allow for the possibility of testing an application's error page.
Note:
If the test below results in a FAIL, do not proceed with further tests. Otherwise, the mobileOK Basic Tests should be applied to the content.
If an HTTP request does not result in a valid HTTP response (because of network-level error, DNS resolution error, or non-HTTP response), FAIL
If the HTTP status indicates redirection (status code 3xx):
Do not carry out tests on the response
If the response relates to a request for the resource under test, or any of its Included Resources (see 2.4.7 Included Resources):
Include the size of the response in the "total size" as described under 3.16 PAGE_SIZE_LIMIT
Include this response under the count as described under 3.6 EXTERNAL_RESOURCES
If there is no HTTP Location header, FAIL.
If the URI identified by the HTTP
Location header is a relative URI, create an absolute URI
by combining the value of the Location header with the
absolute URI of the request to which this is a response, warn
If the resulting URI is not a URI with the scheme
http or https, FAIL.
Re-request the resource using the URI formulated above.
If the HTTP status indicates that authentication is required (e.g. status code 401):
If the response relates to a request for the resource under test, or any of its Included Resources (see 2.4.7 Included Resources):
If authentication information was supplied in the HTTP request (i.e. authentication failed) or if no authentication information is available, FAIL
Carry out tests on the response
Include the size of the response in the "total size" as described under 3.16 PAGE_SIZE_LIMIT
Include this response under the count as described under 3.6 EXTERNAL_RESOURCES
Re-request the resource using authentication information
If the response relates to a request for a linked resource (see 2.4.8 Linked Resources):
Continue with the test (see 3.10 LINK_TARGET_FORMAT , i.e. do not re-request the resource with authentication information), warn
If the HTTP status code is 404 or 5xx
If the response relates to a request for the resource under test, continue with tests on the response and warn
If the response relates to a request for a linked resource (see 2.4.8 Linked Resources), continue with the test (see 3.10 LINK_TARGET_FORMAT ) and warn
Otherwise (i.e. for Included Resources), FAIL
If the HTTP status represents failure (4xx), other than 404, a request for authentication (e.g. 401) or a 406 when carrying out the 3.15.1 Object Element Processing Rule, FAIL
2.4.5 Meta http-equiv Elements
Documents can include meta elements with an
http-equiv attribute; these are sometimes considered
substitutes for HTTP response headers.
mobileOK Basic test implementations must ignore values specified in such elements, aside from the following:
The
Refreshheader as specified in 3.1 AUTO_REFRESH and REDIRECTIONThe
Content-Typeheader as specified in 3.3 CHARACTER_ENCODING_SUPPORT and CHARACTER_ENCODING_USEThe
Cache-Controlheader as specified in 3.2 CACHINGCheck for consistency with HTTP headers, as follows:
For each
metaelement with anhttp-equivattribute:If a matching HTTP response header does not exist, warn
If a matching HTTP response header exists but its value differs from the
contentattribute value, warn
2.4.6 CSS Style
Some tests refer to "CSS Style" information. Assemble the CSS Style by using the contents of:
the
styleattribute of any element (use of thestyleattribute is deprecated in XHTML Basic 1.1 [XHTML Basic 1.1])styleelements whosetypeattribute is "text/css", and whosemediaattribute is either not present or is present and contains values "all" or "handheld" (case-insensitive).resources linked via
linkelements andxml-stylesheetprocessing instructions, where:the
relattribute contains "stylesheet" but not "alternate" (case-insensitive)the
charsetattribute is either not present or is present with value "UTF-8" (case-insensitive)the
typeattribute is either not present or is present with value "text/css"the
mediaattribute is either not present or is present and contains value "all" or "handheld" (case-insensitive).
Note:
In the case of
xml-stylesheetprocessing instructions, attribute in this section refers to pseudo-attribute.resources linked by CSS
@importat-rules whose presentation media list is either not present or is present and contains the value "all" or "handheld"
In the course of assembling the CSS Style use only those CSS rulesets that are not restricted as to their presentation media type or whose presentation media type list contains "handheld" or "all".
2.4.7 Included Resources
Some tests refer to Included Resources, which are resources external to the resource being tested and yet vital to rendering that resource and whose URI has the "http" or "https" scheme, when represented in an absolute form. Examples include image and style sheet resources.
When retrieving resources, caching directives should be observed. Multiple references to cached resources are counted only once in regard of page weight (see 3.16 PAGE_SIZE_LIMIT ) and resource count (see 3.6 EXTERNAL_RESOURCES ).
Included Resources are defined as those that are referenced by the following:
the
srcattribute ofimgelementsthe
dataattribute ofobjectelements (see notes below)the
hrefattribute oflinkelements andxml-stylesheetprocessing instructions as defined in 2.4.6 CSS Styleimages included by
background-imageandlist-style-imageproperties in the CSS Style (see 2.4.6 CSS Style)@importdirectives in the CSS Style - providing they are unqualified as to presentation media type or qualified by presentation media type "handheld" or "all" (case-insensitive) as defined in 2.4.6 CSS Style
Note:
In some circumstances object elements may act as synonyms
for other elements such as img and iframe. In
these cases it is noted in the relevant section when to regard object
elements as equivalents for other elements.
Note:
Resources that are retrieved as references from object elements and whose Content-Type HTTP header is not set to "image/jpeg" or "image/gif" are not considered to be Included Resources as discussed under 3.15.1 Object Element Processing Rule (i.e. objects that are "tasted" to determine their Internet content type but are then discarded are not Included Resources). Their treatment, as regards 3.16
PAGE_SIZE_LIMIT
and 3.6
EXTERNAL_RESOURCES
, is described in the relevant section.
Note:
Resources referenced by descendants of an object element that itself refers to an Included Resource are not considered to be Included Resources as discussed under 3.15.1 Object Element Processing Rule (i.e. any img or object element which occurs in the fall-back of an acceptable object element is not an Included Resource).
2.4.8 Linked Resources
Linked Resources are resources linked to from the resource being tested (other than the resource itself), but which are not vital to rendering that resource whose URI begins with the "http" or "https" scheme when represented in an absolute form.
Linked resources are defined as those that are referenced by:
the
hrefattribute ofa(anchor) elements.the
actionattribute offormelements whosemethodattribute is not present or is present with value "get" (case-insensitive).Note:
Forms with
methodattribute "POST" (case-insensitive) are permissible in documents under test, but are not checked by mobileOK Basic (posting might cause side effects such as the addition of unwanted records to a database).Note:
When submitting forms use default values where supplied, otherwise supply empty values.
2.4.9 Validity
Several tests refer to the validity of aspects of a resource. This section defines specifically what this means.
- CSS
A resource is considered a valid CSS resource if it conforms to the grammar defined in [CSS Level 1], Appendix B. The presence of at-rules, properties or values or combinations of properties and values that are not specified in [CSS Level 1] does not constitute a validity failure for CSS. See 3.21 STYLE_SHEETS_USE for treatment of such values. In addition, the
@mediaat-rule and the presentation media list for the@importat-rule are taken into account when evaluating CSS.- GIF
An image is a valid GIF image if it conforms to the grammar defined in section 25 of the [GIF] specification.
- JPEG
An image is a valid JPEG image if it follows the format defined in Annex B of the [JPEG] specification
- UTF-8
A resource is considered to be valid UTF-8 if its bytes represent the valid UTF-8 encoding of some string, as defined in [RFC 3629], section 4
2.4.10 White Space
Several tests refer to white space. White space has the same definition in this document as in XML. For XML 1.0 [XML 1.0] it is defined in https://www.w3.org/TR/REC-xml/#sec-common-syn as being:
S ::= (#x20 | #x9 | #xD | #xA)+ i.e. the characters SP, TAB, CR
and LF.
3 mobileOK Basic Tests
This section describes tests for mobileOK Basic. Tests are organized alphabetically by the Best Practice from which they derive. Where a test derives from more than one Best Practice it is placed according to the one that occurs first in dictionary order.
3.1 AUTO_REFRESH and REDIRECTION
This test does not determine whether the user is able to opt out of refresh.
If a meta element is present with
http-equiv attribute value of "refresh",
If the URI specified as part of the content
attribute is not the current resource's URI, FAIL
Else, warn
If a Refresh HTTP header is present,
If the URI specified in the header value is not the current resource's URI, FAIL
Else, warn
3.2 CACHING
The purpose of the test is to alert providers to the fact that their content may not be cached, if it would be beneficial to do so.
Note:
Where both a meta element with http-equiv attribute
and the corresponding HTTP header are found, the value of the HTTP header
must be used - see also note under 2.4.5 Meta http-equiv Elements.
If the HTTP response contains neither an
Expires nor Cache-Control header
If no meta http-equiv element is present,
referring to those headers, FAIL
Continue the test using the value from the meta
content attribute as though it were specified in the
appropriate header, warn
If a Cache-Control HTTP header is present and
contains value "no-cache", or contains value
"max-age=0", warn
If a Pragma HTTP header is present and
contains value "no-cache", warn
If an Expires and Date HTTP
header are present, and the Expires header specifies a date
which is not later than what the Date header specifies, warn
If any cache related header contains an invalid value, warn
If the HTTP response contains a Last-Modified
header,
Request the same URI again, adding an
If-Modified-Since request header whose value matches that
of the Last-Modified response header
If the HTTP response contains a Last-Modified
header and its value is again the same, and the HTTP response status is not
304 (Not Modified), warn
If the HTTP response contains an ETag header,
Request the same URI again, adding an
If-None-Match request header whose value matches that of the
ETag response header
If the HTTP response contains an ETag header
and its value is again the same, and the HTTP response status is not 304
(Not Modified), warn
3.3 CHARACTER_ENCODING_SUPPORT and CHARACTER_ENCODING_USE
The DDC is defined to support only UTF-8 encoding, and hence this test fails if a resource is not encoded in UTF-8. The test does not require that resource always be encoded in UTF-8; the test merely checks that the resource is available in UTF-8 encoding, if requested. Resources may be represented using other encodings where appropriate. This test verifies that a DDC-like device which only accepts UTF-8 encoding may access the resource in UTF-8 encoding.
This test requires that character encoding is explicitly specified and recognizes the following methods of specification:
HTTP
Content-Typeheaderapplication/xhtml+xml; charset=UTF-8
XML declaration
<?xml version="1.0" encoding="UTF-8" ?>
metaelement that is the first child of the document'sheadelement, and whosehttp-equivattribute is "Content-Type", and whosecontentattribute specifies a character encoding... <head> <meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8"/> ...
If the HTTP Content-Type header specifies a
character encoding other than UTF-8, FAIL
If the HTTP Content-Type header does not
specify a character encoding:
If there is no XML declaration, or UTF-8 character encoding is not specified in the XML declaration, FAIL
If the HTTP Content-Type header specifies an
Internet media type starting with "text/":
If there is no meta element with
http-equiv attribute that specifies UTF-8 character
encoding, FAIL
If character encoding is specified in more than one way, and not all values are the same, FAIL
If the document is not valid UTF-8 (see 2.4.9 Validity), FAIL
For each resource specified by 2.4.7 Included Resources:
Request the resource
If the HTTP Content-Type header value of the
response starts with "text/" but does not specify UTF-8
character encoding, warn
3.4 CONTENT_FORMAT_SUPPORT and VALID_MARKUP
Note:
In the following, an "html document" is a document that has "html" as its root element.
Note:
In the following, "regardless of its
stated DOCTYPE" means that when
assessing validity against the XHTML Basic 1.1 and XHTML MP 1.2 DTDs this
may be carried out by inserting a DOCTYPE if none is present,
or by replacing the given DOCTYPE with the appropriate
DOCTYPE for the DTD under test.
Note:
In the following, "a known XHTML version" means XHTML Basic 1.0, XHTML Basic 1.1, XHTML-MP 1.0, XHTML-MP 1.1 or XHTML-MP 1.2.
If the document's Internet media type, as specified in the
HTTP response Content-Type header, is not
"application/xhtml+xml",
"application/vnd.wap.xhtml+xml", or
"text/html", FAIL
If the document's Internet media type is "text/html" or "application/vnd.wap.xhtml+xml", warn
If the document does not contain a DOCTYPE
declaration, FAIL
If the document is not an HTML document, FAIL
If the DOCTYPE is not an XML
DOCTYPE, warn
If the document is an HTML
document and it has an XML DOCTYPE:
If the document does not declare the html namespace on its
html root element, FAIL
If the DOCTYPE refers to a known XHTML version, validate against that
DOCTYPE and if invalid, warn
Otherwise (if the DOCTYPE is not known), warn
If (regardless of its stated DOCTYPE) the document does not validate against the XHTML Basic 1.1 DTD:
If (regardless of its stated DOCTYPE) it does not validate against the XHTML-MP 1.2 DTD, FAIL
For each Included Resource (see 2.4.7 Included Resources):
If the response specifies an Internet media type that is not "text/css", "image/jpeg" or "image/gif", FAIL
If an image is required (see also 3.15 OBJECTS_OR_SCRIPT ) and the response specifies an Internet media type that is not "image/jpeg" or "image/gif", FAIL
If the Internet media type is "image/gif" or "image/jpeg", and the resource is not valid (see 2.4.9 Validity), FAIL
If a style sheet is required and the response specifies an Internet media type that is not "text/css", FAIL
If the Internet media type is "text/css" and the content is not valid CSS (see 2.4.9 Validity), FAIL
3.5 DEFAULT_INPUT_MODE
Note:
inputmode is part of [XHTML Basic 1.1].
For each input element with attribute
type whose value is "text" or
"password" or whose type attribute is
missing:
If the element's inputmode attribute is
invalid according to Section 5.2 User Agent
Behavior of XHTML Basic 1.1 [XHTML Basic 1.1], FAIL
If the element's value attribute is missing
or empty, and an inputmode attribute is not present, warn
For each textarea element:
If the element's inputmode attribute is
invalid according to Section 5.2 User Agent
Behavior of XHTML Basic 1.1 [XHTML Basic 1.1], FAIL
If the element is empty and an inputmode
attribute is not present, warn
3.6 EXTERNAL_RESOURCES
Retrieve the resource under test, and add the number of retrievals required to obtain the resource (see 2.4.4 HTTP Response) to a running total.
For each unique Included Resource, as defined in 2.4.7 Included Resources:
Request the referenced resource
Add the number of HTTP requests that are required to retrieve the resource (see 2.4.4 HTTP Response) to the running total. Include in the count only those objects retrieved under the 3.15.1 Object Element Processing Rule whose type attribute is not specified, and those whose content type is either "image/jpeg" or "image/gif" irrespective of whether the type attribute is specified.
If the total exceeds 10, warn
If this total exceeds 20, FAIL
3.7 GRAPHICS_FOR_SPACING
The intent of this Best Practice is to avoid using transparent images for spacing. However, small transparent images are often used in e-commerce sites for user tracking purposes. The practice is common enough, and possibly vital enough to the business interests of mobile sites, that it is undesirable to fail sites that use such small transparent images. Therefore this machine-testable test merely warns about the presence of small (at most 2x2) transparent images and FAILs larger ones. It is believed that few if any sites would use transparent images of any significant size for tracking.
For each img element and
object element which is an Included Resource (see 2.4.7 Included Resources):
If all pixels are transparent,
If image height and width are both less than or equal to 2 pixels, warn
If either dimension exceeds 2 pixels, FAIL
If more than one image with all transparent pixels is present, warn
3.8 IMAGE_MAPS
If an input element with type
attribute set to "image" is present, FAIL
For each img element and object
element which is an Included Resource (see 2.4.7 Included Resources):
If a usemap attribute is present, FAIL
If an ismap attribute is present, FAIL
3.9 IMAGES_RESIZING and IMAGES_SPECIFY_SIZE
Note:
The height and width HTML attributes specify pixels
when they are used as a number. No unit is specified.
For each img element and
object element which is an Included Resource (see 2.4.7 Included Resources):
If the height or width attribute
are missing, FAIL
If the height or width attribute
do not specify a size in pixels, FAIL
If the value specified by either the height or width attribute is greater than the corresponding dimension of the image, warn
If the value specified by either the height or width attribute is less than the corresponding dimension of the image, FAIL
3.10 LINK_TARGET_FORMAT
Note:
404 and 5xx HTTP status do not result in failure when conducting this test.
Note:
The document body of linked resources is not examined.
For each linked resource, as defined in 2.4.8 Linked Resources:
Request the resource
If the Content-Type header value of the HTTP
response is not one of the Internet media types listed in the
Accept header in 2.4.3 HTTP Request, warn
If the Content-Type header value of the HTTP
response does not specify a charset parameter, or does but it
is not consistent with the value of the Accept-Charset header
in 2.4.3 HTTP Request, warn
For each document internal reference (links in the document under test that refer to the document itself):
If there is no target for the reference or it is invalid (e.g. '#'), warn
3.11 MEASURES
Note:
The intrinsic size of images must be specified as attributes of the
img element and not as CSS properties (see 3.9
IMAGES_RESIZING and IMAGES_SPECIFY_SIZE)
Note:
Only CSS Level 1 properties are considered in this test.
For each CSS Level 1 property in the CSS Style (see 2.4.6 CSS Style) whose value is a numeric measure of length stated together with a unit:
If the value is non-zero and the unit is not "em" or "ex" (and the value is not a percentage), and the property is not a margin, border or padding box property, FAIL
3.12 MINIMIZE
Note:
Extraneous white space characters in script and in CSS are not considered in this test. Such an extension may be considered in a future revision of this specification.
Count number of white space characters (see 2.4.10 White Space) in a sequence of more than one white space
character (not counting the first), which exist outside of a
pre, style, script element, or XML
comment.
Add to this count the number of characters comprising XML comments. This total is the number of extraneous characters in the document.
Count total number of characters in document.
If the number of extraneous characters exceeds 10% of the count of characters in the document, warn
If the number of extraneous characters exceeds 25% of the count of characters in the document, FAIL
3.13 NO_FRAMES
If the document contains a frame,
frameset or iframe element, FAIL
3.14 NON-TEXT_ALTERNATIVES
This test does not determine whether the alternative text is meaningful.
Note:
An empty alt attribute is acceptable and signifies that there is
no meaningful textual alternative, for example for images that are purely
decorative.
For each img element:
If an alt attribute is not present or
contains only white space, FAIL
3.15 OBJECTS_OR_SCRIPT
This test does not determine whether the document is still usable without the objects or scripts.
If a script element is present, warn
If any element has an "intrinsic event"
attribute (currently onload, onunload,
onclick, ondblclick, onmousedown,
onmouseup, onmouseover,
onmousemove, onmouseout, onfocus,
onblur, onkeypress, onkeydown,
onkeyup, onsubmit, onreset,
onselect, onchange), warn
For each a and link element:
If the value of the href attribute begins
with the "javascript:" scheme, FAIL
If an applet element is present, FAIL
Set the context to the root element and apply the Object Element Processing Rule
3.15.1 Object Element Processing Rule
For each img element that has no
object element ancestor (other than the context node) in this context:
Treat this image as an Included Resource (and carry out appropriate tests).
For each object element that has no object element ancestor (other than the context node) in this context:
If the object element is empty, warn
If the content of the object element consists only of
white space, FAIL
If there is no type attribute, warn
If it is not already cached (see 2.4.7 Included Resources), retrieve the referenced resource (ignoring the type attribute)
If the Internet media type of the retrieved resource, as indicated by its Content-Type HTTP header does not match that stated in the type attribute, warn
If the Internet media type indicated by the Content-Type HTTP Header of the retrieved resource is not "image/jpeg" or "image/gif", warn
Reapply this rule using the current object element as the
context
Otherwise (the object is an acceptable image):
Treat this object as an Included Resource (and carry out appropriate tests), ignore img and object elements that are descendants of the current object element.
Note:
A warning is issued when the Internet media type indicated by the type attribute is not compatible with the Default Delivery Context because some user agents do not take into account the type attribute of object elements and this may cause the user agent to retrieve large incompatible objects with consequences to performance and cost.
Note:
An HTTP 406 status on retrieval of a resource referenced by an object element does not constitute a FAIL.
3.16 PAGE_SIZE_LIMIT
Retrieve the document under test, if its size (excluding any redirections discussed under 2.4.4 HTTP Response) exceeds 10 kilobytes, FAIL
Add to a running total (total size) the size of all the HTTP response bodies that are required to retrieve the document under test (2.4.4 HTTP Response).
For each unique Included Resource, as defined in 2.4.7 Included Resources:
Add the size of all the response bodies that are required to retrieve the resource (see 2.4.4 HTTP Response) to the running total. Include in the total only those objects retrieved under the 3.15.1 Object Element Processing Rule whose type attribute is not specified, and those whose Internet media type as indicated by the Content-Type HTTP header is either "image/jpeg" or "image/gif" irrespective of whether the type attribute is specified.
If the total exceeds 20 kilobytes, FAIL
Note:
In the case of resources that are referenced more than once in the document under test, and where, as discussed under 2.4.7 Included Resources, they are cached, it is the initial retrieval of that resource (as determined by the first reference in document order) that counts towards the total.
Note:
Where the 3.15.1 Object Element Processing Rule yields a resource that is found to be cached, objects that must be assessed in the course of yielding the cached resource count towards the total.
3.17 PAGE_TITLE
This test does not determine whether the title is meaningful.
If a title element is not present in the
head element, or is empty, or contains only white space
(see 2.4.10 White Space), FAIL
3.18 POP_UPS
For each a, link,
form, and base element:
If a target attribute is present,
If its value is not one of "_self", "_parent", or "_top", FAIL
3.19 PROVIDE_DEFAULTS
For each radio button group within a form
element (input elements with type
"radio" that share the same name attribute
value):
Check that exactly one input element within
this group has its checked attribute set to
"checked", and if this is not the case, warn
For each select element:
If there is no nested option element whose
selected attribute is set to "selected",
warn
If there is more than one option element
whose selected attribute is set to
"selected", and the multiple attribute is not
set to "multiple", warn
3.20 STYLE_SHEETS_SUPPORT
If the CSS Style (see 2.4.6 CSS Style) contains rules referencing
the position, display or float
properties, warn
3.21 STYLE_SHEETS_USE
This test looks for elements in the Text Extension module defined by [XHTML Modularization], some of which are not supported in XHTML Basic [XHTML Basic 1.1]. It also looks for commonly-used elements and attributes that were deprecated in HTML 4, and are not supported, or are deprecated, in XHTML Basic.
Note:
This test does not require that any CSS Style is used, since in some cases, no presentation information is required at all (for example, a simple page of text).
If the document contains any basefont,
bdo, center, del,
dir, font, ins, menu,
s, strike or u elements, FAIL
If the document contains any b,
big, i, small, sub,
sup or tt elements, warn
If any element has a style attribute, warn
If all styles are restricted to presentation media types other than
"handheld" or "all" by means of @media
at-rules, warn
If the CSS Style contains at-rules (other than the
@media at-rule, and the presentation media type list of the
@import at-rule), properties, or values that are not recognized
as being specified in CSS Level 1, or if the value of a recognized CSS Level 1 property is incompatible with the property, warn
3.22 TABLES_ALTERNATIVES
If a table element exists, warn
3.23 TABLES_LAYOUT
This test does not catch all cases where tables are used for layout purposes.
For each table element:
If it contains at most one tr element, FAIL
If no tr element contains more than one
td element, FAIL
For each nested td element:
If the element contains only an image (or equivalent object) whose actual dimensions are 2x2 or less, FAIL
3.24 TABLES_NESTED
For each table element:
If it contains a table element, FAIL
A Acknowledgments (Non-Normative)
The editors would like to thank members of the BPWG for contributions of various kinds.
The editors acknowledge significant written contributions from:
- Dominique Hazaël-Massieux, W3C
- Phil Archer, ICRA
- François Daoust, W3C
B References (Non-Normative)
- Best Practices
- Mobile Web Best Practices 1.0, Jo Rabin, Charles McCathieNevile, W3C Recommendation, 29 July 2008 (See https://www.w3.org/TR/2008/REC-mobile-bp-20080729/)
- CSS Level 1
- Cascading Style Sheets, level 1, Håkon Wium Lie, Bert Bos, W3C Recommendation 17 Dec 1996, revised 11 Jan 1999 (See https://www.w3.org/TR/1999/REC-CSS1-19990111/)
- GIF
- GRAPHICS INTERCHANGE FORMAT, Version 89a, CompuServe Incorporated, 1990 (See https://www.w3.org/Graphics/GIF/spec-gif89a.txt)
- JPEG
- Recommendation T.81, 18 September 1992 (See https://www.w3.org/Graphics/JPEG/itu-t81.pdf)
- RFC 2119
- Key words for use in RFCs to Indicate Requirement Levels, S. Bradner, March 1997 (See https://tools.ietf.org/html/rfc2119.txt)
- RFC 2616
- Hypertext Transfer Protocol -- HTTP/1.1 Request for Comments: 2616, R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Leach, T. Berners-Lee, June 1999 (See https://tools.ietf.org/html/rfc2616)
- RFC 2617
- HTTP Authentication: Basic and Digest Access Authentication, J. Franks, P. Hallam-Baker, J. Hostetler, S. Lawrence, P. Leach, A. Luotonen, L. Stewart, June 1999 (See https://tools.ietf.org/html/rfc2617)
- RFC 3629
- UTF-8, a transformation format of ISO 10646, F. Yergau, November 2003 (See https://tools.ietf.org/html/rfc3629)
- WCAG 1.0
- Web Content Accessibility Guidelines 1.0, W. Chisholm, G. Vanderheiden and I. Jacobs, eds., W3C Recommendation, 5 May 1999 (See https://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/)
- XHTML Basic 1.1
- XHTML™ Basic 1.1, Mark Baker, Masayasu Ishikawa, Shinichi Matsui, Peter Stark, Ted Wugofski, Toshihiko Yamakami (eds), W3C Recommendation, 29 July 2008 (See https://www.w3.org/TR/2008/REC-xhtml-basic-20080729/)
- XHTML Modularization
- XHTML™ Modularization 1.1, Daniel Austin, Subramanian Peruvemba, Shane McCarron, Masayasu Ishikawa, Mark Birbeck (eds), W3C Recommendation, 08 October 2008 (See https://www.w3.org/TR/2008/REC-xhtml-modularization-20081008/)
- XML 1.0
- Extensible Markup Language (XML) 1.0 (Fifth Edition), Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, Eve Maler, François Yergeau, W3C Recommendation 26 November 2008 (See https://www.w3.org/TR/2008/REC-xml-20081126/)
C Relationship between Best Practices and mobileOK Tests (Non-Normative)
This appendix lists all Best Practices and indicates whether each has a corresponding test in mobileOK Basic.