1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/xul/templates/src/nsTemplateRule.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,328 @@
1.4 +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef nsTemplateRule_h__
1.10 +#define nsTemplateRule_h__
1.11 +
1.12 +#include "nsCOMPtr.h"
1.13 +#include "nsIAtom.h"
1.14 +#include "nsIRDFDataSource.h"
1.15 +#include "nsIRDFResource.h"
1.16 +#include "nsIContent.h"
1.17 +#include "nsIDOMNode.h"
1.18 +#include "nsTArray.h"
1.19 +#include "nsString.h"
1.20 +#include "nsIXULTemplateRuleFilter.h"
1.21 +#include "nsCycleCollectionParticipant.h"
1.22 +
1.23 +class nsIXULTemplateQueryProcessor;
1.24 +class nsTemplateQuerySet;
1.25 +
1.26 +class nsTemplateCondition
1.27 +{
1.28 +public:
1.29 + // relations that may be used in a rule. They may be negated with the
1.30 + // negate flag. Less and Greater are used for numeric comparisons and
1.31 + // Before and After are used for string comparisons. For Less, Greater,
1.32 + // Before, After, Startswith, Endswith, and Contains, the source is
1.33 + // conceptually on the left of the relation and the target is on the
1.34 + // right. For example, if the relation is Contains, that means Match if
1.35 + // the source contains the target.
1.36 + enum ConditionRelation {
1.37 + eUnknown,
1.38 + eEquals,
1.39 + eLess,
1.40 + eGreater,
1.41 + eBefore,
1.42 + eAfter,
1.43 + eStartswith,
1.44 + eEndswith,
1.45 + eContains
1.46 + };
1.47 +
1.48 + nsTemplateCondition(nsIAtom* aSourceVariable,
1.49 + const nsAString& aRelation,
1.50 + nsIAtom* aTargetVariable,
1.51 + bool mIgnoreCase,
1.52 + bool mNegate);
1.53 +
1.54 + nsTemplateCondition(nsIAtom* aSourceVariable,
1.55 + const nsAString& aRelation,
1.56 + const nsAString& aTargets,
1.57 + bool mIgnoreCase,
1.58 + bool mNegate,
1.59 + bool aIsMultiple);
1.60 +
1.61 + nsTemplateCondition(const nsAString& aSource,
1.62 + const nsAString& aRelation,
1.63 + nsIAtom* aTargetVariable,
1.64 + bool mIgnoreCase,
1.65 + bool mNegate);
1.66 +
1.67 + ~nsTemplateCondition() { MOZ_COUNT_DTOR(nsTemplateCondition); }
1.68 +
1.69 + nsTemplateCondition* GetNext() { return mNext; }
1.70 + void SetNext(nsTemplateCondition* aNext) { mNext = aNext; }
1.71 +
1.72 + void SetRelation(const nsAString& aRelation);
1.73 +
1.74 + bool
1.75 + CheckMatch(nsIXULTemplateResult* aResult);
1.76 +
1.77 + bool
1.78 + CheckMatchStrings(const nsAString& aLeftString,
1.79 + const nsAString& aRightString);
1.80 +protected:
1.81 +
1.82 + nsCOMPtr<nsIAtom> mSourceVariable;
1.83 + nsString mSource;
1.84 + ConditionRelation mRelation;
1.85 + nsCOMPtr<nsIAtom> mTargetVariable;
1.86 + nsTArray<nsString> mTargetList;
1.87 + bool mIgnoreCase;
1.88 + bool mNegate;
1.89 +
1.90 + nsTemplateCondition* mNext;
1.91 +};
1.92 +
1.93 +/**
1.94 + * A rule consists of:
1.95 + *
1.96 + * - Conditions, a set of unbound variables with consistency
1.97 + * constraints that specify the values that each variable can
1.98 + * assume. The conditions must be completely and consistently
1.99 + * "bound" for the rule to be considered "matched".
1.100 + *
1.101 + * - Bindings, a set of unbound variables with consistency constraints
1.102 + * that specify the values that each variable can assume. Unlike the
1.103 + * conditions, the bindings need not be bound for the rule to be
1.104 + * considered matched.
1.105 + *
1.106 + * - Content that should be constructed when the rule is "activated".
1.107 + *
1.108 + */
1.109 +class nsTemplateRule
1.110 +{
1.111 +public:
1.112 + nsTemplateRule(nsIContent* aRuleNode,
1.113 + nsIContent* aAction,
1.114 + nsTemplateQuerySet* aQuerySet);
1.115 + /**
1.116 + * The copy-constructor should only be called from nsTArray when appending
1.117 + * a new rule, otherwise things break because the copy constructor expects
1.118 + * mBindings and mConditions to be nullptr.
1.119 + */
1.120 + nsTemplateRule(const nsTemplateRule& aOtherRule);
1.121 +
1.122 + ~nsTemplateRule();
1.123 +
1.124 + /**
1.125 + * Return the <action> node that this rule was constructed from, or its
1.126 + * logical equivalent for shorthand syntaxes. That is, the parent node of
1.127 + * the content that should be generated for this rule.
1.128 + */
1.129 + nsIContent* GetAction() const { return mAction; }
1.130 +
1.131 + /**
1.132 + * Return the <rule> content node that this rule was constructed from.
1.133 + * @param aResult an out parameter, which will contain the rule node
1.134 + * @return NS_OK if no errors occur.
1.135 + */
1.136 + nsresult GetRuleNode(nsIDOMNode** aResult) const;
1.137 +
1.138 + void SetVars(nsIAtom* aRefVariable, nsIAtom* aMemberVariable)
1.139 + {
1.140 + mRefVariable = aRefVariable;
1.141 + mMemberVariable = aMemberVariable;
1.142 + }
1.143 +
1.144 + void SetRuleFilter(nsIXULTemplateRuleFilter* aRuleFilter)
1.145 + {
1.146 + mRuleFilter = aRuleFilter;
1.147 + }
1.148 +
1.149 + nsIAtom* GetTag() { return mTag; }
1.150 + void SetTag(nsIAtom* aTag) { mTag = aTag; }
1.151 +
1.152 + nsIAtom* GetMemberVariable() { return mMemberVariable; }
1.153 +
1.154 + /**
1.155 + * Set the first condition for the rule. Other conditions are linked
1.156 + * to it using the condition's SetNext method.
1.157 + */
1.158 + void SetCondition(nsTemplateCondition* aConditions);
1.159 +
1.160 + /**
1.161 + * Check if the result matches the rule by first looking at the conditions.
1.162 + * If the results is accepted by the conditions, the rule filter, if any
1.163 + * was set, is checked. If either check rejects a result, a match cannot
1.164 + * occur for this rule and result.
1.165 + */
1.166 + bool
1.167 + CheckMatch(nsIXULTemplateResult* aResult) const;
1.168 +
1.169 + /**
1.170 + * Determine if the rule has the specified binding
1.171 + */
1.172 + bool
1.173 + HasBinding(nsIAtom* aSourceVariable,
1.174 + nsAString& aExpr,
1.175 + nsIAtom* aTargetVariable) const;
1.176 +
1.177 + /**
1.178 + * Add a binding to the rule. A binding consists of an already-bound
1.179 + * source variable, and the RDF property that should be tested to
1.180 + * generate a target value. The target value is bound to a target
1.181 + * variable.
1.182 + *
1.183 + * @param aSourceVariable the source variable that will be used in
1.184 + * the RDF query.
1.185 + * @param aExpr the expression that will be used in the query.
1.186 + * @param aTargetVariable the variable whose value will be bound
1.187 + * to the RDF node that is returned when querying the binding
1.188 + * @return NS_OK if no errors occur.
1.189 + */
1.190 + nsresult AddBinding(nsIAtom* aSourceVariable,
1.191 + nsAString& aExpr,
1.192 + nsIAtom* aTargetVariable);
1.193 +
1.194 + /**
1.195 + * Inform the query processor of the bindings that are set for a rule.
1.196 + * This should be called after all the bindings for a rule are compiled.
1.197 + */
1.198 + nsresult
1.199 + AddBindingsToQueryProcessor(nsIXULTemplateQueryProcessor* aProcessor);
1.200 +
1.201 + void Traverse(nsCycleCollectionTraversalCallback &cb) const
1.202 + {
1.203 + cb.NoteXPCOMChild(mRuleNode);
1.204 + cb.NoteXPCOMChild(mAction);
1.205 + }
1.206 +
1.207 +protected:
1.208 +
1.209 + struct Binding {
1.210 + nsCOMPtr<nsIAtom> mSourceVariable;
1.211 + nsCOMPtr<nsIAtom> mTargetVariable;
1.212 + nsString mExpr;
1.213 + Binding* mNext;
1.214 + Binding* mParent;
1.215 + };
1.216 +
1.217 + // backreference to the query set which owns this rule
1.218 + nsTemplateQuerySet* mQuerySet;
1.219 +
1.220 + // the <rule> node, or the <template> node if there is no <rule>
1.221 + nsCOMPtr<nsIDOMNode> mRuleNode;
1.222 +
1.223 + // the <action> node, or, if there is no <action>, the container node
1.224 + // which contains the content to generate
1.225 + nsCOMPtr<nsIContent> mAction;
1.226 +
1.227 + // the rule filter set by the builder's SetRuleFilter function
1.228 + nsCOMPtr<nsIXULTemplateRuleFilter> mRuleFilter;
1.229 +
1.230 + // indicates that the rule will only match when generating content
1.231 + // to be inserted into a container with this tag
1.232 + nsCOMPtr<nsIAtom> mTag;
1.233 +
1.234 + // linked-list of the bindings for the rule, owned by the rule.
1.235 + Binding* mBindings;
1.236 +
1.237 + nsCOMPtr<nsIAtom> mRefVariable;
1.238 + nsCOMPtr<nsIAtom> mMemberVariable;
1.239 +
1.240 + nsTemplateCondition* mConditions; // owned by nsTemplateRule
1.241 +};
1.242 +
1.243 +/** nsTemplateQuerySet
1.244 + *
1.245 + * A single <queryset> which holds the query node and the rules for it.
1.246 + * All builders have at least one queryset, which may be created with an
1.247 + * explicit <queryset> tag or implied if the tag is not used.
1.248 + *
1.249 + * These queryset objects are created and owned by the builder in its
1.250 + * mQuerySets array.
1.251 + */
1.252 +class nsTemplateQuerySet
1.253 +{
1.254 +protected:
1.255 + nsTArray<nsTemplateRule> mRules;
1.256 +
1.257 + // a number which increments for each successive queryset. It is stored so
1.258 + // it can be used as an optimization when updating results so that it is
1.259 + // known where to insert them into a match.
1.260 + int32_t mPriority;
1.261 +
1.262 +public:
1.263 +
1.264 + // <query> node
1.265 + nsCOMPtr<nsIContent> mQueryNode;
1.266 +
1.267 + // compiled opaque query object returned by the query processor's
1.268 + // CompileQuery call
1.269 + nsCOMPtr<nsISupports> mCompiledQuery;
1.270 +
1.271 + // indicates that the query will only generate content to be inserted into
1.272 + // a container with this tag
1.273 + nsCOMPtr<nsIAtom> mTag;
1.274 +
1.275 + nsTemplateQuerySet(int32_t aPriority)
1.276 + : mPriority(aPriority)
1.277 + {
1.278 + MOZ_COUNT_CTOR(nsTemplateQuerySet);
1.279 + }
1.280 +
1.281 + ~nsTemplateQuerySet()
1.282 + {
1.283 + MOZ_COUNT_DTOR(nsTemplateQuerySet);
1.284 + }
1.285 +
1.286 + int32_t Priority() const
1.287 + {
1.288 + return mPriority;
1.289 + }
1.290 +
1.291 + nsIAtom* GetTag() { return mTag; }
1.292 + void SetTag(nsIAtom* aTag) { mTag = aTag; }
1.293 +
1.294 + nsTemplateRule* NewRule(nsIContent* aRuleNode,
1.295 + nsIContent* aAction,
1.296 + nsTemplateQuerySet* aQuerySet)
1.297 + {
1.298 + // nsTemplateMatch stores the index as a 16-bit value,
1.299 + // so check to make sure for overflow
1.300 + if (mRules.Length() == INT16_MAX)
1.301 + return nullptr;
1.302 +
1.303 + return mRules.AppendElement(nsTemplateRule(aRuleNode, aAction,
1.304 + aQuerySet));
1.305 + }
1.306 +
1.307 + void RemoveRule(nsTemplateRule *aRule)
1.308 + {
1.309 + mRules.RemoveElementAt(aRule - mRules.Elements());
1.310 + }
1.311 +
1.312 + int16_t RuleCount() const
1.313 + {
1.314 + return mRules.Length();
1.315 + }
1.316 +
1.317 + nsTemplateRule* GetRuleAt(int16_t aIndex)
1.318 + {
1.319 + if (uint32_t(aIndex) < mRules.Length()) {
1.320 + return &mRules[aIndex];
1.321 + }
1.322 + return nullptr;
1.323 + }
1.324 +
1.325 + void Clear()
1.326 + {
1.327 + mRules.Clear();
1.328 + }
1.329 +};
1.330 +
1.331 +#endif // nsTemplateRule_h__
