gecko-dev/dom/xul/templates/nsTemplateRule.h

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef nsTemplateRule_h__
#define nsTemplateRule_h__
#include "nsCOMPtr.h"
#include "nsIAtom.h"
#include "nsIRDFDataSource.h"
#include "nsIRDFResource.h"
#include "nsIContent.h"
#include "nsIDOMNode.h"
#include "nsTArray.h"
#include "nsString.h"
#include "nsIXULTemplateRuleFilter.h"
#include "nsCycleCollectionParticipant.h"
class nsIXULTemplateQueryProcessor;
class nsTemplateQuerySet;
class nsTemplateCondition
{
public:
// relations that may be used in a rule. They may be negated with the
// negate flag. Less and Greater are used for numeric comparisons and
// Before and After are used for string comparisons. For Less, Greater,
// Before, After, Startswith, Endswith, and Contains, the source is
// conceptually on the left of the relation and the target is on the
// right. For example, if the relation is Contains, that means Match if
// the source contains the target.
enum ConditionRelation {
eUnknown,
eEquals,
eLess,
eGreater,
eBefore,
eAfter,
eStartswith,
eEndswith,
eContains
};
nsTemplateCondition(nsIAtom* aSourceVariable,
const nsAString& aRelation,
nsIAtom* aTargetVariable,
bool mIgnoreCase,
bool mNegate);
nsTemplateCondition(nsIAtom* aSourceVariable,
const nsAString& aRelation,
const nsAString& aTargets,
bool mIgnoreCase,
bool mNegate,
bool aIsMultiple);
nsTemplateCondition(const nsAString& aSource,
const nsAString& aRelation,
nsIAtom* aTargetVariable,
bool mIgnoreCase,
bool mNegate);
~nsTemplateCondition() { MOZ_COUNT_DTOR(nsTemplateCondition); }
nsTemplateCondition* GetNext() { return mNext; }
void SetNext(nsTemplateCondition* aNext) { mNext = aNext; }
void SetRelation(const nsAString& aRelation);
bool
CheckMatch(nsIXULTemplateResult* aResult);
bool
CheckMatchStrings(const nsAString& aLeftString,
const nsAString& aRightString);
protected:
nsCOMPtr<nsIAtom> mSourceVariable;
nsString mSource;
ConditionRelation mRelation;
nsCOMPtr<nsIAtom> mTargetVariable;
nsTArray<nsString> mTargetList;
bool mIgnoreCase;
bool mNegate;
nsTemplateCondition* mNext;
};
/**
* A rule consists of:
*
* - Conditions, a set of unbound variables with consistency
* constraints that specify the values that each variable can
* assume. The conditions must be completely and consistently
* "bound" for the rule to be considered "matched".
*
* - Bindings, a set of unbound variables with consistency constraints
* that specify the values that each variable can assume. Unlike the
* conditions, the bindings need not be bound for the rule to be
* considered matched.
*
* - Content that should be constructed when the rule is "activated".
*
*/
class nsTemplateRule
{
public:
nsTemplateRule(nsIContent* aRuleNode,
nsIContent* aAction,
nsTemplateQuerySet* aQuerySet);
/**
* The copy-constructor should only be called from nsTArray when appending
* a new rule, otherwise things break because the copy constructor expects
* mBindings and mConditions to be nullptr.
*/
nsTemplateRule(const nsTemplateRule& aOtherRule);
~nsTemplateRule();
/**
* Return the <action> node that this rule was constructed from, or its
* logical equivalent for shorthand syntaxes. That is, the parent node of
* the content that should be generated for this rule.
*/
nsIContent* GetAction() const { return mAction; }
/**
* Return the <rule> content node that this rule was constructed from.
* @param aResult an out parameter, which will contain the rule node
* @return NS_OK if no errors occur.
*/
nsresult GetRuleNode(nsIDOMNode** aResult) const;
void SetVars(nsIAtom* aRefVariable, nsIAtom* aMemberVariable)
{
mRefVariable = aRefVariable;
mMemberVariable = aMemberVariable;
}
void SetRuleFilter(nsIXULTemplateRuleFilter* aRuleFilter)
{
mRuleFilter = aRuleFilter;
}
nsIAtom* GetTag() { return mTag; }
void SetTag(nsIAtom* aTag) { mTag = aTag; }
nsIAtom* GetMemberVariable() { return mMemberVariable; }
/**
* Set the first condition for the rule. Other conditions are linked
* to it using the condition's SetNext method.
*/
void SetCondition(nsTemplateCondition* aConditions);
/**
* Check if the result matches the rule by first looking at the conditions.
* If the results is accepted by the conditions, the rule filter, if any
* was set, is checked. If either check rejects a result, a match cannot
* occur for this rule and result.
*/
bool
CheckMatch(nsIXULTemplateResult* aResult) const;
/**
* Determine if the rule has the specified binding
*/
bool
HasBinding(nsIAtom* aSourceVariable,
nsAString& aExpr,
nsIAtom* aTargetVariable) const;
/**
* Add a binding to the rule. A binding consists of an already-bound
* source variable, and the RDF property that should be tested to
* generate a target value. The target value is bound to a target
* variable.
*
* @param aSourceVariable the source variable that will be used in
* the RDF query.
* @param aExpr the expression that will be used in the query.
* @param aTargetVariable the variable whose value will be bound
* to the RDF node that is returned when querying the binding
* @return NS_OK if no errors occur.
*/
nsresult AddBinding(nsIAtom* aSourceVariable,
nsAString& aExpr,
nsIAtom* aTargetVariable);
/**
* Inform the query processor of the bindings that are set for a rule.
* This should be called after all the bindings for a rule are compiled.
*/
nsresult
AddBindingsToQueryProcessor(nsIXULTemplateQueryProcessor* aProcessor);
void Traverse(nsCycleCollectionTraversalCallback &cb) const
{
cb.NoteXPCOMChild(mRuleNode);
cb.NoteXPCOMChild(mAction);
}
protected:
struct Binding {
nsCOMPtr<nsIAtom> mSourceVariable;
nsCOMPtr<nsIAtom> mTargetVariable;
nsString mExpr;
Binding* mNext;
Binding* mParent;
};
// backreference to the query set which owns this rule
nsTemplateQuerySet* mQuerySet;
// the <rule> node, or the <template> node if there is no <rule>
nsCOMPtr<nsIDOMNode> mRuleNode;
// the <action> node, or, if there is no <action>, the container node
// which contains the content to generate
nsCOMPtr<nsIContent> mAction;
// the rule filter set by the builder's SetRuleFilter function
nsCOMPtr<nsIXULTemplateRuleFilter> mRuleFilter;
// indicates that the rule will only match when generating content
// to be inserted into a container with this tag
nsCOMPtr<nsIAtom> mTag;
// linked-list of the bindings for the rule, owned by the rule.
Binding* mBindings;
nsCOMPtr<nsIAtom> mRefVariable;
nsCOMPtr<nsIAtom> mMemberVariable;
nsTemplateCondition* mConditions; // owned by nsTemplateRule
};
/** nsTemplateQuerySet
*
* A single <queryset> which holds the query node and the rules for it.
* All builders have at least one queryset, which may be created with an
* explicit <queryset> tag or implied if the tag is not used.
*
* These queryset objects are created and owned by the builder in its
* mQuerySets array.
*/
class nsTemplateQuerySet
{
protected:
nsTArray<nsTemplateRule> mRules;
// a number which increments for each successive queryset. It is stored so
// it can be used as an optimization when updating results so that it is
// known where to insert them into a match.
int32_t mPriority;
public:
// <query> node
nsCOMPtr<nsIContent> mQueryNode;
// compiled opaque query object returned by the query processor's
// CompileQuery call
nsCOMPtr<nsISupports> mCompiledQuery;
// indicates that the query will only generate content to be inserted into
// a container with this tag
nsCOMPtr<nsIAtom> mTag;
explicit nsTemplateQuerySet(int32_t aPriority)
: mPriority(aPriority)
{
MOZ_COUNT_CTOR(nsTemplateQuerySet);
}
~nsTemplateQuerySet()
{
MOZ_COUNT_DTOR(nsTemplateQuerySet);
}
int32_t Priority() const
{
return mPriority;
}
nsIAtom* GetTag() { return mTag; }
void SetTag(nsIAtom* aTag) { mTag = aTag; }
nsTemplateRule* NewRule(nsIContent* aRuleNode,
nsIContent* aAction,
nsTemplateQuerySet* aQuerySet)
{
// nsTemplateMatch stores the index as a 16-bit value,
// so check to make sure for overflow
if (mRules.Length() == INT16_MAX)
return nullptr;
return mRules.AppendElement(nsTemplateRule(aRuleNode, aAction,
aQuerySet));
}
void RemoveRule(nsTemplateRule *aRule)
{
mRules.RemoveElementAt(aRule - mRules.Elements());
}
int16_t RuleCount() const
{
return mRules.Length();
}
nsTemplateRule* GetRuleAt(int16_t aIndex)
{
if (uint32_t(aIndex) < mRules.Length()) {
return &mRules[aIndex];
}
return nullptr;
}
void Clear()
{
mRules.Clear();
}
};
#endif // nsTemplateRule_h__