changeset
[selectors] Rebase the data model onto DOM explicitly.
Tue, 22 Apr 2014 16:18:54 -0700
- author
- Tab Atkins Jr. <jackalmage@gmail.com>
- date
- Tue, 22 Apr 2014 16:18:54 -0700
- changeset 13786
- 625b67ab1d46
- parent 13785
- a423f0deea6d
- child 13787
- a310692c2ad8
[selectors] Rebase the data model onto DOM explicitly.
| selectors/Overview.bs | file | annotate | diff | comparison | revisions | |
| selectors/Overview.html | file | annotate | diff | comparison | revisions |
1.1 --- a/selectors/Overview.bs Mon Apr 21 18:53:08 2014 -0700 1.2 +++ b/selectors/Overview.bs Tue Apr 22 16:18:54 2014 -0700 1.3 @@ -20,7 +20,7 @@ 1.4 Abstract: Selectors Level 4 describes the selectors that already exist in [[!SELECT]], and further introduces new selectors for CSS and other languages that may need them. 1.5 At Risk: the column combinator 1.6 At Risk: The '':drop()'' pseudo-class 1.7 -Ignored Terms: DocumentFragment, math, h1, shadow tree, box tree, query() 1.8 +Ignored Terms: DocumentFragment, math, h1, shadow tree, box tree, query(), element tree 1.9 Link Defaults: html5 (element) a 1.10 </pre> 1.11 <style> 1.12 @@ -666,24 +666,36 @@ 1.13 <h3 id='data-model'> 1.14 Data Model</h3> 1.15 1.16 - Selectors are matched against an <dfn export>element tree</dfn>, 1.17 - which is an abstract tree structure containing elements 1.18 - having the structure defined in the <a href="http://dom.spec.whatwg.org/#trees">DOM Standard</a> [[!DOM]]. 1.19 - 1.20 - Each element may have any of: 1.21 + Selectors are evaluated against a DOM tree. [[!DOM]] 1.22 + Within this specification, 1.23 + this may be referred to as the "document tree". 1.24 + 1.25 + In addition to the information present in the document tree, 1.26 + for the purpose of selectors, 1.27 + elements are assumed to have arbitrary <a>pseudo-class</a> flags 1.28 + and <a>pseudo-element</a> slots, 1.29 + as defined by the given <a>pseudo-class</a> and <a>pseudo-element</a>. 1.30 + 1.31 + <div class='example'> 1.32 + For example, the first element child of each element 1.33 + has a flag indicating that it matches the '':first-child'' pseudo-element. 1.34 + 1.35 + For another example, 1.36 + all elements have ''::before'' pseudo-elements, 1.37 + but not only elements with <a>shadow trees</a> have ''::shadow'' pseudo-elements. 1.38 + </div> 1.39 + 1.40 + Four aspects of a DOM element are especially relevant for selectors: 1.41 1.42 <ul> 1.43 - <li>A type, which is a pair of strings: a namespace and a local name. 1.44 + <li>The element's type (also known as tagname), 1.45 + which is a pair of strings: a namespace and a local name. 1.46 <li>An ID, which is a string. 1.47 <li>Classes, which are strings. 1.48 <li>Attributes, which are pairs of strings consisting of an attribute name and an attribute value. 1.49 - <li>A list of child elements. 1.50 - <li>Arbitrary additional information, 1.51 - which isn't directly accessible, 1.52 - but can be used in the matching of pseudo-classes and pseudo-elements. 1.53 </ul> 1.54 1.55 - The first four bullet points in the list above are referred to as <dfn export title="feature">features</dfn>. 1.56 + These aspects are referred to as <dfn export title="feature">features</dfn>. 1.57 The <a>simple selectors</a> which are keyed off of them 1.58 (<a>universal selector</a>, <a>type selectors</a>, <a>ID selectors</a>, <a>class selectors</a>, and <a>attribute selectors</a>) 1.59 are called <dfn export title="feature selector">feature selectors</dfn>. 1.60 @@ -697,17 +709,113 @@ 1.61 also never match them. 1.62 Thus, only <a>pseudo-classes</a> or <a>pseudo-elements</a> can be used to select them. 1.63 Individual <a>featureless</a> elements may define additional restrictions on what kinds of selectors can match them. 1.64 - (For example, the <a>host element</a> in a <a>shadow tree</a> is <a>featureless</a>, 1.65 - and can't be matched by <em>any</em> <a>pseudo-class</a> except for '':host'' and '':host-context()''.) 1.66 - 1.67 - In a DOM document, 1.68 - the DOM is used as the <a>element tree</a>. 1.69 - Each DOM element is an element in the <a>element tree</a>, 1.70 - with the DOM element's namespace and local name as the type, 1.71 - and its ID, class list, attributes, and child elements 1.72 - as the ID, classes, attributes, and child elements in the <a>element tree</a>. 1.73 - The rest of the information in the DOM is also accessible 1.74 - as the arbitrary additional information in the <a>element tree</a>. 1.75 + 1.76 + <div class='example'> 1.77 + For example, the <a>host element</a> in a <a>shadow tree</a> is <a>featureless</a>, 1.78 + and can't be matched by <em>any</em> <a>pseudo-class</a> except for '':host'' and '':host-context()''.) 1.79 + </div> 1.80 + 1.81 +<h4 id='dom-mapping'> 1.82 +Guidance on Mapping Document Languages to DOM</h4> 1.83 + 1.84 + The DOM document structure is powerful and useful, 1.85 + but generic enough to model pretty much any langauge that describes tree-based data 1.86 + (or even graph-based, with a suitable interpretation). 1.87 + 1.88 + Some languages, like HTML, already have well-defined procedures 1.89 + for producing a DOM object from a resource. 1.90 + If a given language does not, 1.91 + such a procedure must be defined 1.92 + in order for Selectors to apply to documents in that language. 1.93 + 1.94 + At minimum, 1.95 + the document language must define what maps to the DOM concept of an "element". 1.96 + 1.97 + The primary one-to-many relationship between nodes-- 1.98 + parent/child in tree-based structures, 1.99 + element/neighbors in graph-based structures-- 1.100 + should be reflected as the child nodes of an element. 1.101 + 1.102 + Other features of the element should be reflected as <a>features</a> when possible, 1.103 + mapping to something that serves a similar purpose to the same feature in DOM: 1.104 + 1.105 + <dl> 1.106 + <dt>type 1.107 + <dd> 1.108 + If the elements in the document language have some notion of "type" 1.109 + as a basic distinguisher between different groups of elements, 1.110 + it should be reflected as the "type" <a>feature</a>. 1.111 + 1.112 + If this "type" can be separated into a "basic" name 1.113 + and a "namespace" that groups names into higher-level groups, 1.114 + that should be reflected in the "namespace" and "local name" divisions of the "type" <a>feature</a>. 1.115 + Otherwise, the "namespace" part should be the empty string, 1.116 + and the entire name should be in the "local name" part. 1.117 + 1.118 + <dt>id 1.119 + <dd> 1.120 + If some aspect of the element functions as a unique identifier across the document, 1.121 + it should be mapped to the "id" <a>feature</a>. 1.122 + 1.123 + Note: While HTML only allows an element to have a single ID, 1.124 + this should not be taken as a general restriction. 1.125 + The important quality of an ID is that each ID should be associated with a single element; 1.126 + a single element can validly have multiple IDs. 1.127 + 1.128 + <dt>classes and attributes 1.129 + <dd> 1.130 + Aspects of the element that are useful for identifying the element, 1.131 + but are not generally unique to elements within a document, 1.132 + should be mapped to the "class" or "attribute" <a>features</a> 1.133 + depending on if they're something equivalent to a "label" (a string by itself) 1.134 + or a "property" (a name/value pair) 1.135 + 1.136 + <dt>pseudo-classes and pseudo-attributes 1.137 + <dd> 1.138 + If any elements match any pseudo-classes or have any pseudo-elements, 1.139 + that must be explicitly defined. 1.140 + 1.141 + Issue: Some pseudo-classes are *syntactical*, 1.142 + like '':has()'' and '':matches()'', 1.143 + and thus should always work. 1.144 + Need to indicate that somewhere. 1.145 + Probably the structural pseudos always work 1.146 + whenever the child list is ordered. 1.147 + </dl> 1.148 + 1.149 + <div class='example'> 1.150 + For example, <a href>JSONSelect</a> is a library that uses selectors 1.151 + to extract information from JSON documents. 1.152 + 1.153 + <ul> 1.154 + <li> 1.155 + The "elements" of the JSON document 1.156 + are each array, object, boolean, string, number, or null. 1.157 + The array and object elements have their contents as children. 1.158 + 1.159 + <li> 1.160 + Each element's type is its JS type name: 1.161 + "array", "object", etc. 1.162 + 1.163 + <li> 1.164 + Children of an object 1.165 + have their key as a class. 1.166 + 1.167 + <li> 1.168 + Children of an array match the '':first-child'', '':nth-child()'', etc pseudo-classes. 1.169 + 1.170 + <li> 1.171 + The root object matches '':root''. 1.172 + 1.173 + <li> 1.174 + It additionally defines '':val()'' and '':contains()'' pseudo-classes, 1.175 + for matching boolean/number/string elements with a particular value 1.176 + or which contain a particular substring. 1.177 + </ul> 1.178 + 1.179 + This structure is sufficient to allow powerful, compact querying of JSON documents with selectors. 1.180 + </div> 1.181 + 1.182 1.183 1.184 <h3 id="scoping">
2.1 --- a/selectors/Overview.html Mon Apr 21 18:53:08 2014 -0700 2.2 +++ b/selectors/Overview.html Tue Apr 22 16:18:54 2014 -0700 2.3 @@ -59,7 +59,7 @@ 2.4 </p> 2.5 <h1 class="p-name no-ref" id=title>Selectors Level 4</h1> 2.6 <h2 class="no-num no-toc no-ref heading settled heading" id=subtitle><span class=content>Editor’s Draft, 2.7 - <span class=dt-updated><span class=value-title title=20140418>18 April 2014</span></span></span></h2> 2.8 + <span class=dt-updated><span class=value-title title=20140422>22 April 2014</span></span></span></h2> 2.9 <div data-fill-with=spec-metadata><dl><dt>This version:<dd><a class=u-url href=http://dev.w3.org/csswg/selectors>http://dev.w3.org/csswg/selectors</a><dt>Latest version:<dd><a href=http://www.w3.org/TR/selectors/>http://www.w3.org/TR/selectors/</a><dt>Editor’s Draft:<dd><a href=http://dev.w3.org/csswg/selectors>http://dev.w3.org/csswg/selectors</a><dt>Previous Versions:<dd><a href=http://www.w3.org/TR/2013/WD-selectors4-20130502/ rel=previous>http://www.w3.org/TR/2013/WD-selectors4-20130502/</a><dd><a href=http://www.w3.org/TR/2012/WD-selectors4-20120823/ rel=previous>http://www.w3.org/TR/2012/WD-selectors4-20120823/</a><dd><a href=http://www.w3.org/TR/2011/WD-selectors4-20110929/ rel=previous>http://www.w3.org/TR/2011/WD-selectors4-20110929/</a> 2.10 <dt>Feedback:</dt> 2.11 <dd><a href="mailto:www-style@w3.org?subject=%5Bselectors%5D%20feedback">www-style@w3.org</a> 2.12 @@ -124,6 +124,8 @@ 2.13 <li><a href=#structure><span class=secno>3.1</span> Structure and Terminology</a> 2.14 <li><a href=#evaluating-selectors><span class=secno>3.2</span> Evaluating a Selector</a> 2.15 <li><a href=#data-model><span class=secno>3.3</span> Data Model</a> 2.16 + <ul class=toc> 2.17 + <li><a href=#dom-mapping><span class=secno>3.3.1</span> Guidance on Mapping Document Languages to DOM</a></ul> 2.18 <li><a href=#scoping><span class=secno>3.4</span> Scoped Selectors</a> 2.19 <li><a href=#relative><span class=secno>3.5</span> Relative Selectors</a> 2.20 <ul class=toc> 2.21 @@ -801,7 +803,7 @@ 2.22 <p> This section describes how to <dfn data-dfn-type=dfn data-export="" id=evaluate-a-selector>evaluate a selector<a class=self-link href=#evaluate-a-selector></a></dfn> against a set of elements. 2.23 2.24 <p> APIs using this algorithm must provide a selector, 2.25 - and one or more <a data-link-type=dfn href=#element-tree title="element tree">element tree</a> root elements 2.26 + and one or more <a data-link-type=dfn title="element tree">element tree</a> root elements 2.27 indicating the trees that will be searched by the selector. 2.28 They may optionally provide: 2.29 2.30 @@ -831,7 +833,7 @@ 2.31 2.32 <p> A <a data-link-type=dfn href=#selector title=selector>selector</a> is evaluated against some initial list of elements: 2.33 the <dfn data-dfn-type=dfn data-export="" id=selector-match-list>selector match list<a class=self-link href=#selector-match-list></a></dfn>. 2.34 - The <a data-link-type=dfn href=#selector-match-list title="selector match list">selector match list</a> is initially populated with the <a data-link-type=dfn href=#element-tree title="element tree">element tree</a> roots 2.35 + The <a data-link-type=dfn href=#selector-match-list title="selector match list">selector match list</a> is initially populated with the <a data-link-type=dfn title="element tree">element tree</a> roots 2.36 provided to the algorithm, 2.37 and all elements reachable from them by traversing any number of child lists. 2.38 2.39 @@ -894,24 +896,36 @@ 2.40 <h3 class="heading settled heading" data-level=3.3 id=data-model><span class=secno>3.3 </span><span class=content> 2.41 Data Model</span><a class=self-link href=#data-model></a></h3> 2.42 2.43 -<p> Selectors are matched against an <dfn data-dfn-type=dfn data-export="" id=element-tree>element tree<a class=self-link href=#element-tree></a></dfn>, 2.44 - which is an abstract tree structure containing elements 2.45 - having the structure defined in the <a href=http://dom.spec.whatwg.org/#trees>DOM Standard</a> <a data-biblio-type=normative data-link-type=biblio href=#dom title=dom>[DOM]</a>. 2.46 - 2.47 -<p> Each element may have any of: 2.48 +<p> Selectors are evaluated against a DOM tree. <a data-biblio-type=normative data-link-type=biblio href=#dom title=dom>[DOM]</a> 2.49 + Within this specification, 2.50 + this may be referred to as the "document tree". 2.51 + 2.52 +<p> In addition to the information present in the document tree, 2.53 + for the purpose of selectors, 2.54 + elements are assumed to have arbitrary <a data-link-type=dfn href=#pseudo-class title=pseudo-class>pseudo-class</a> flags 2.55 + and <a data-link-type=dfn href=#pseudo-element title=pseudo-element>pseudo-element</a> slots, 2.56 + as defined by the given <a data-link-type=dfn href=#pseudo-class title=pseudo-class>pseudo-class</a> and <a data-link-type=dfn href=#pseudo-element title=pseudo-element>pseudo-element</a>. 2.57 + 2.58 + <div class=example> 2.59 + For example, the first element child of each element 2.60 + has a flag indicating that it matches the <a class=css data-link-type=maybe href=#first-child-pseudo title=:first-child>:first-child</a> pseudo-element. 2.61 + 2.62 +<p> For another example, 2.63 + all elements have <span class=css data-link-type=maybe title=::before>::before</span> pseudo-elements, 2.64 + but not only elements with <a data-link-type=dfn href=http://dev.w3.org/csswg/css-scoping-1/#shadow-tree title="shadow trees">shadow trees</a> have <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-scoping-1/#selectordef-shadow title=::shadow>::shadow</a> pseudo-elements. 2.65 + </div> 2.66 + 2.67 +<p> Four aspects of a DOM element are especially relevant for selectors: 2.68 2.69 <p> <ul> 2.70 - <li>A type, which is a pair of strings: a namespace and a local name. 2.71 + <li>The element’s type (also known as tagname), 2.72 + which is a pair of strings: a namespace and a local name. 2.73 <li>An ID, which is a string. 2.74 <li>Classes, which are strings. 2.75 <li>Attributes, which are pairs of strings consisting of an attribute name and an attribute value. 2.76 - <li>A list of child elements. 2.77 - <li>Arbitrary additional information, 2.78 - which isn’t directly accessible, 2.79 - but can be used in the matching of pseudo-classes and pseudo-elements. 2.80 </ul> 2.81 2.82 -<p> The first four bullet points in the list above are referred to as <dfn data-dfn-type=dfn data-export="" id=feature title=feature>features<a class=self-link href=#feature></a></dfn>. 2.83 +<p> These aspects are referred to as <dfn data-dfn-type=dfn data-export="" id=feature title=feature>features<a class=self-link href=#feature></a></dfn>. 2.84 The <a data-link-type=dfn href=#simple title="simple selectors">simple selectors</a> which are keyed off of them 2.85 (<a data-link-type=dfn href=#universal-selector0 title="universal selector">universal selector</a>, <a data-link-type=dfn href=#type-selector title="type selectors">type selectors</a>, <a data-link-type=dfn href=#id-selector title="id selectors">ID selectors</a>, <a data-link-type=dfn href=#class-selector title="class selectors">class selectors</a>, and <a data-link-type=dfn href=#attribute-selector title="attribute selectors">attribute selectors</a>) 2.86 are called <dfn data-dfn-type=dfn data-export="" id=feature-selector title="feature selector">feature selectors<a class=self-link href=#feature-selector></a></dfn>. 2.87 @@ -925,17 +939,111 @@ 2.88 also never match them. 2.89 Thus, only <a data-link-type=dfn href=#pseudo-class title=pseudo-classes>pseudo-classes</a> or <a data-link-type=dfn href=#pseudo-element title=pseudo-elements>pseudo-elements</a> can be used to select them. 2.90 Individual <a data-link-type=dfn href=#featureless title=featureless>featureless</a> elements may define additional restrictions on what kinds of selectors can match them. 2.91 - (For example, the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-scoping-1/#host-element0 title="host element">host element</a> in a <a data-link-type=dfn href=http://dev.w3.org/csswg/css-scoping-1/#shadow-tree title="shadow tree">shadow tree</a> is <a data-link-type=dfn href=#featureless title=featureless>featureless</a>, 2.92 - and can’t be matched by <em>any</em> <a data-link-type=dfn href=#pseudo-class title=pseudo-class>pseudo-class</a> except for <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-scoping-1/#selectordef-host0 title=:host>:host</a> and <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-scoping-1/#selectordef-host-context title=:host-context()>:host-context()</a>.) 2.93 - 2.94 -<p> In a DOM document, 2.95 - the DOM is used as the <a data-link-type=dfn href=#element-tree title="element tree">element tree</a>. 2.96 - Each DOM element is an element in the <a data-link-type=dfn href=#element-tree title="element tree">element tree</a>, 2.97 - with the DOM element’s namespace and local name as the type, 2.98 - and its ID, class list, attributes, and child elements 2.99 - as the ID, classes, attributes, and child elements in the <a data-link-type=dfn href=#element-tree title="element tree">element tree</a>. 2.100 - The rest of the information in the DOM is also accessible 2.101 - as the arbitrary additional information in the <a data-link-type=dfn href=#element-tree title="element tree">element tree</a>. 2.102 + 2.103 + <div class=example> 2.104 + For example, the <a data-link-type=dfn href=http://dev.w3.org/csswg/css-scoping-1/#host-element0 title="host element">host element</a> in a <a data-link-type=dfn href=http://dev.w3.org/csswg/css-scoping-1/#shadow-tree title="shadow tree">shadow tree</a> is <a data-link-type=dfn href=#featureless title=featureless>featureless</a>, 2.105 + and can’t be matched by <em>any</em> <a data-link-type=dfn href=#pseudo-class title=pseudo-class>pseudo-class</a> except for <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-scoping-1/#selectordef-host0 title=:host>:host</a> and <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-scoping-1/#selectordef-host-context title=:host-context()>:host-context()</a>.) 2.106 + </div> 2.107 + 2.108 +<h4 class="heading settled heading" data-level=3.3.1 id=dom-mapping><span class=secno>3.3.1 </span><span class=content> 2.109 +Guidance on Mapping Document Languages to DOM</span><a class=self-link href=#dom-mapping></a></h4> 2.110 + 2.111 +<p> The DOM document structure is powerful and useful, 2.112 + but generic enough to model pretty much any langauge that describes tree-based data 2.113 + (or even graph-based, with a suitable interpretation). 2.114 + 2.115 +<p> Some languages, like HTML, already have well-defined procedures 2.116 + for producing a DOM object from a resource. 2.117 + If a given language does not, 2.118 + such a procedure must be defined 2.119 + in order for Selectors to apply to documents in that language. 2.120 + 2.121 +<p> At minimum, 2.122 + the document language must define what maps to the DOM concept of an "element". 2.123 + 2.124 +<p> The primary one-to-many relationship between nodes—<wbr>parent/child in tree-based structures, 2.125 + element/neighbors in graph-based structures—<wbr>should be reflected as the child nodes of an element. 2.126 + 2.127 +<p> Other features of the element should be reflected as <a data-link-type=dfn href=#feature title=features>features</a> when possible, 2.128 + mapping to something that serves a similar purpose to the same feature in DOM: 2.129 + 2.130 + <dl> 2.131 + <dt>type 2.132 + <dd> 2.133 + If the elements in the document language have some notion of "type" 2.134 + as a basic distinguisher between different groups of elements, 2.135 + it should be reflected as the "type" <a data-link-type=dfn href=#feature title=feature>feature</a>. 2.136 + 2.137 +<p> If this "type" can be separated into a "basic" name 2.138 + and a "namespace" that groups names into higher-level groups, 2.139 + that should be reflected in the "namespace" and "local name" divisions of the "type" <a data-link-type=dfn href=#feature title=feature>feature</a>. 2.140 + Otherwise, the "namespace" part should be the empty string, 2.141 + and the entire name should be in the "local name" part. 2.142 + 2.143 + <dt>id 2.144 + <dd> 2.145 + If some aspect of the element functions as a unique identifier across the document, 2.146 + it should be mapped to the "id" <a data-link-type=dfn href=#feature title=feature>feature</a>. 2.147 + 2.148 +<p class=note> Note: While HTML only allows an element to have a single ID, 2.149 + this should not be taken as a general restriction. 2.150 + The important quality of an ID is that each ID should be associated with a single element; 2.151 + a single element can validly have multiple IDs. 2.152 + 2.153 + <dt>classes and attributes 2.154 + <dd> 2.155 + Aspects of the element that are useful for identifying the element, 2.156 + but are not generally unique to elements within a document, 2.157 + should be mapped to the "class" or "attribute" <a data-link-type=dfn href=#feature title=features>features</a> 2.158 + depending on if they’re something equivalent to a "label" (a string by itself) 2.159 + or a "property" (a name/value pair) 2.160 + 2.161 + <dt>pseudo-classes and pseudo-attributes 2.162 + <dd> 2.163 + If any elements match any pseudo-classes or have any pseudo-elements, 2.164 + that must be explicitly defined. 2.165 + 2.166 +<p class=issue id=issue-66b7c28d><a class=self-link href=#issue-66b7c28d></a> Some pseudo-classes are *syntactical*, 2.167 + like <span class=css data-link-type=maybe title=:has()>:has()</span> and <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a>, 2.168 + and thus should always work. 2.169 + Need to indicate that somewhere. 2.170 + Probably the structural pseudos always work 2.171 + whenever the child list is ordered. 2.172 + </dl> 2.173 + 2.174 + <div class=example> 2.175 + For example, <a href="">JSONSelect</a> is a library that uses selectors 2.176 + to extract information from JSON documents. 2.177 + 2.178 +<p> <ul> 2.179 + <li> 2.180 + The "elements" of the JSON document 2.181 + are each array, object, boolean, string, number, or null. 2.182 + The array and object elements have their contents as children. 2.183 + 2.184 + <li> 2.185 + Each element’s type is its JS type name: 2.186 + "array", "object", etc. 2.187 + 2.188 + <li> 2.189 + Children of an object 2.190 + have their key as a class. 2.191 + 2.192 + <li> 2.193 + Children of an array match the <a class=css data-link-type=maybe href=#first-child-pseudo title=:first-child>:first-child</a>, <a class=css data-link-type=maybe href=#nth-child-pseudo title=:nth-child()>:nth-child()</a>, etc pseudo-classes. 2.194 + 2.195 + <li> 2.196 + The root object matches <a class=css data-link-type=maybe href=#root-pseudo title=:root>:root</a>. 2.197 + 2.198 + <li> 2.199 + It additionally defines <span class=css data-link-type=maybe title=:val()>:val()</span> and <span class=css data-link-type=maybe title=:contains()>:contains()</span> pseudo-classes, 2.200 + for matching boolean/number/string elements with a particular value 2.201 + or which contain a particular substring. 2.202 + </ul> 2.203 + 2.204 +<p> This structure is sufficient to allow powerful, compact querying of JSON documents with selectors. 2.205 + </div> 2.206 + 2.207 2.208 2.209 <h3 class="heading settled heading" data-level=3.4 id=scoping><span class=secno>3.4 </span><span class=content> 2.210 @@ -3631,7 +3739,6 @@ 2.211 <li>:disabled, <a href=#disabled-pseudo title="section 11.1.1">11.1.1</a> 2.212 <li>:drop(), <a href=#selectordef-drop title="section 9.4">9.4</a> 2.213 <li>:drop, <a href=#selectordef-drop0 title="section 9.4">9.4</a> 2.214 -<li>element tree, <a href=#element-tree title="section 3.3">3.3</a> 2.215 <li>:empty, <a href=#empty-pseudo title="section 12.2">12.2</a> 2.216 <li>:enabled, <a href=#enabled-pseudo title="section 11.1.1">11.1.1</a> 2.217 <li>evaluate a selector, <a href=#evaluate-a-selector title="section 3.2">3.2</a> 2.218 @@ -3742,7 +3849,13 @@ 2.219 before something <em>is</em> exposed. 2.220 2.221 2.222 -<a href=#issue-1bcc9de6> ↵ </a></div><div class=issue> 2.223 +<a href=#issue-1bcc9de6> ↵ </a></div><div class=issue> Some pseudo-classes are *syntactical*, 2.224 + like <span class=css data-link-type=maybe title=:has()>:has()</span> and <a class=css data-link-type=maybe href=#matches-pseudo title=:matches()>:matches()</a>, 2.225 + and thus should always work. 2.226 + Need to indicate that somewhere. 2.227 + Probably the structural pseudos always work 2.228 + whenever the child list is ordered. 2.229 + <a href=#issue-66b7c28d> ↵ </a></div><div class=issue> 2.230 I’ve switched over to defaulting to allowing. 2.231 Is that okay, 2.232 or should we stick with defaulting to *not* allowing,
