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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /dom/xul/templates/nsIXULTemplateQueryProcessor.idl | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
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Add m-esr52 at 52.6.0
Diffstat (limited to 'dom/xul/templates/nsIXULTemplateQueryProcessor.idl')
-rw-r--r-- | dom/xul/templates/nsIXULTemplateQueryProcessor.idl | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/dom/xul/templates/nsIXULTemplateQueryProcessor.idl b/dom/xul/templates/nsIXULTemplateQueryProcessor.idl new file mode 100644 index 000000000..e064cf3b8 --- /dev/null +++ b/dom/xul/templates/nsIXULTemplateQueryProcessor.idl @@ -0,0 +1,276 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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/. */ + +#include "domstubs.idl" + +interface nsIAtom; +interface nsIArray; +interface nsISimpleEnumerator; +interface nsIXULTemplateResult; +interface nsIXULTemplateRuleFilter; +interface nsIXULTemplateBuilder; + +/** + * A query processor takes a template query and generates results for it given + * a datasource and a reference point. There is a one-to-one relationship + * between a template builder and a query processor. The template builder + * creates the query processor, and there is no other means to retrieve it. + * + * A template query is the contents inside a <query> element within the + * template. The actual syntax is opaque to the template builder and defined + * by a query processor. The query is expected to consist of either text or + * DOM nodes that, when executed by a call to the generateResults method, will + * allow the generation of a list of results. + * + * The template builder will supply two variables, the reference variable and + * the member variable to further indicate what part of the datasource is to + * be examined in addition to the query itself. The reference is always + * a placeholder for the starting point and the member is always a placeholder + * for the end points (the results). + * + * The reference point is important when generating output recursively, as + * the query will be the same for each iteration, however, the reference point + * will differ. + * + * For instance, when examining an XML source, an XML query processor might + * begin at the node referred by the reference variable and end at a list of + * that node's children. + * + * Some queries may not need the reference variable if the syntax or the form + * of the data implies the value. For instance, a datasource that holds a + * table that can only produce one set of results. + * + * The reference variable may be specified in a template by setting the + * "container" attribute on the <template> element to the variable to use. The + * member variable may be specified in a similar way using the "member" + * attribute, or it may be specified in the first <action> body in the + * template as the value of a uri attribute on an element. A breadth-first + * search of the first action is performed to find this element. + * + * If unspecified, the default value of the reference variable is ?uri. + * + * For example, a query might have the following syntax: + * + * (?id, ?name, ?url) from Bookmarks where parentfolder = ?start + * + * This query might generate a result for each bookmark within a given folder. + * The variable ?start would be the reference variable, while the variable ?id + * would be the member variable, since it is the unique value that identifies + * a result. Each result will have the four variables referred to defined for + * it and the values may be retrieved using the result's getBindingFor and + * getBindingObjectFor methods. + * + * The template builder must call initializeForBuilding before the other + * methods, except for translateRef. The builder will then call compileQuery + * for each query in the template to compile the queries. When results need + * to be generated, the builder will call generateResults. The + * initializeForBuilding, compileQuery and addBinding methods may not be + * called after generateResults has been called until the builder indicates + * that the generated output is being removed by calling the done method. + * + * Currently, the datasource supplied to the methods will always be an + * nsIRDFDataSource or a DOM node, and will always be the same one in between + * calls to initializeForBuilding and done. + */ +[scriptable, uuid(C257573F-444F-468A-BA27-DE979DC55FE4)] +interface nsIXULTemplateQueryProcessor : nsISupports +{ + /** + * Retrieve the datasource to use for the query processor. The list of + * datasources in a template is specified using the datasources attribute as + * a space separated list of URIs. This list is processed by the builder and + * supplied to the query processor in the aDataSources array as a list of + * nsIURI objects or nsIDOMNode objects. This method may return an object + * corresponding to these URIs and the builder will supply this object to + * other query processor methods. For example, for an XML source, the + * datasource might be an nsIDOMNode. + * + * All of these URIs are checked by the builder so it is safe to use them, + * however note that a URI that redirects may still needs to be checked to + * ensure that the document containing aRootNode may access it. This is the + * responsibility of the query processor if it needs to load the content of + * the URI. + * + * If the query processor needs to load the datasource asynchronously, it + * may set the aShouldDelayBuilding returned parameter to true to delay + * building the template content, and call the builder's Rebuild method when + * the data is available. + * + * @param aDataSources the list of nsIURI objects and/or nsIDOMNode objects + * @param aRootNode the root node the builder is attached to + * @param aIsTrusted true if the template is in a trusted document + * @param aBuilder the template builder + * @param aShouldDelayBuilding [out] whether the builder should wait to + * build the content or not + * @returns a datasource object + */ + nsISupports getDatasource(in nsIArray aDataSources, + in nsIDOMNode aRootNode, + in boolean aIsTrusted, + in nsIXULTemplateBuilder aBuilder, + out boolean aShouldDelayBuilding); + + /** + * Initialize for query generation. This will be called before the rules are + * processed and whenever the template is rebuilt. This method must be + * called once before any of the other query processor methods except for + * translateRef. + * + * @param aDatasource datasource for the data + * @param aBuilder the template builder + * @param aRootNode the root node the builder is attached to + * + * @throws NS_ERROR_INVALID_ARG if the datasource is not supported or + * NS_ERROR_UNEXPECTED if generateResults has already been called. + */ + void initializeForBuilding(in nsISupports aDatasource, + in nsIXULTemplateBuilder aBuilder, + in nsIDOMNode aRootNode); + + /** + * Called when the template builder is being destroyed so that the query + * processor can clean up any state. The query processor should remove as + * much state as possible, such as results or references to the builder. + * This method will also be called when the template is going to be rebuilt. + */ + void done(); + + /** + * Compile a query from a node. The result of this function will later be + * passed to generateResults for result generation. If null is returned, + * the query will be ignored. + * + * The template builder will call this method once for each query within + * the template, before any results can be generated using generateResults, + * but after initializeForBuilding has been called. This method should not + * be called again for the same query unless the template is rebuilt. + * + * The reference variable may be used by the query processor as a + * placeholder for the reference point, or starting point in the query. + * + * The member variable is determined from the member attribute on the + * template, or from the uri in the first action's rule if that attribute is + * not present. A rule processor may use the member variable as a hint to + * indicate what variable is expected to contain the results. + * + * @param aBuilder the template builder + * @param aQuery <query> node to compile + * @param aRefVariable the reference variable + * @param aMemberVariable the member variable + * + * @returns a compiled query object + */ + nsISupports compileQuery(in nsIXULTemplateBuilder aBuilder, + in nsIDOMNode aQuery, + in nsIAtom aRefVariable, + in nsIAtom aMemberVariable); + + /** + * Generate the results of a query and return them in an enumerator. The + * enumerator must contain nsIXULTemplateResult objects. If there are no + * results, an empty enumerator must be returned. + * + * The datasource will be the same as the one passed to the earlier + * initializeForBuilding method. The context reference (aRef) is a reference + * point used when calculating results. + * + * The value of aQuery must be the result of a previous call to compileQuery + * from this query processor. This method may be called multiple times, + * typically with different values for aRef. + * + * @param aDatasource datasource for the data + * @param aRef context reference value used as a starting point + * @param aQuery the compiled query returned from query compilation + * + * @returns an enumerator of nsIXULTemplateResult objects as the results + * + * @throws NS_ERROR_INVALID_ARG if aQuery is invalid + */ + nsISimpleEnumerator generateResults(in nsISupports aDatasource, + in nsIXULTemplateResult aRef, + in nsISupports aQuery); + + /** + * Add a variable binding for a particular rule. A binding allows an + * additional variable to be set for a result, outside of those defined + * within the query. These bindings are always optional, in that they will + * never affect the results generated. + * + * This function will never be called after generateResults. Any bindings + * that were added should be applied to each result when the result's + * ruleMatched method is called, since the bindings are different for each + * rule. + * + * The reference aRef may be used to determine the reference when + * calculating the value for the binding, for example when a value should + * depend on the value of another variable. + * + * The syntax of the expression aExpr is defined by the query processor. If + * the syntax is invalid, the binding should be ignored. Only fatal errors + * should be thrown, or NS_ERROR_UNEXPECTED if generateResults has already + * been called. + * + * As an example, if the reference aRef is the variable '?count' which + * holds the value 5, and the expression aExpr is the string '+2', the value + * of the variable aVar would be 7, assuming the query processor considers + * the syntax '+2' to mean add two to the reference. + * + * @param aRuleNode rule to add the binding to + * @param aVar variable that will be bound + * @param aRef variable that holds reference value + * @param aExpr expression used to compute the value to assign + */ + void addBinding(in nsIDOMNode aRuleNode, + in nsIAtom aVar, + in nsIAtom aRef, + in AString aExpr); + + /** + * Translate a ref attribute string into a result. This is used as the + * reference point by the template builder when generating the first level + * of content. For recursive generation, the result from the parent + * generation phase will be used directly as the reference so a translation + * is not needed. This allows all levels to be generated using objects that + * all implement the nsIXULTemplateResult interface. + * + * This method may be called before initializeForBuilding, so the + * implementation may use the supplied datasource if it is needed to + * translate the reference. + * + * @param aDatasource datasource for the data + * @param aRefString the ref attribute string + * + * @return the translated ref + */ + nsIXULTemplateResult translateRef(in nsISupports aDatasource, + in AString aRefString); + + /** + * Compare two results to determine their order, used when sorting results. + * This method should return -1 when the left result is less than the right, + * 0 if both are equivalent, and 1 if the left is greater than the right. + * The comparison should only consider the values for the specified + * variable. + * + * If the comparison variable is null, the results may be + * sorted in a natural order, for instance, based on the order the data in + * stored in the datasource. + * + * The sort hints are the flags in nsIXULSortService. + * + * This method must only be called with results that were created by this + * query processor. + * + * @param aLeft the left result to compare + * @param aRight the right result to compare + * @param aVar variable to compare + * + * @param returns -1 if less, 0 if equal, or 1 if greater + */ + int32_t compareResults(in nsIXULTemplateResult aLeft, + in nsIXULTemplateResult aRight, + in nsIAtom aVar, + in unsigned long aSortHints); +}; |