mediawiki-extensions-Visual.../modules/parser/ext.core.TemplateHandler.js
2012-02-13 14:17:03 +00:00

533 lines
16 KiB
JavaScript

/**
* Template and template argument handling, first cut.
*
* AsyncTokenTransformManager objects provide preprocessor-frame-like
* functionality once template args etc are fully expanded, and isolate
* individual transforms from concurrency issues. Template expansion is
* controlled using a tplExpandData structure created independently for each
* handled template tag.
*
* @author Gabriel Wicke <gwicke@wikimedia.org>
* @author Brion Vibber <brion@wikimedia.org>
*/
var $ = require('jquery'),
request = require('request'),
events = require('events'),
qs = require('querystring'),
ParserFunctions = require('./ext.core.ParserFunctions.js').ParserFunctions,
AttributeTransformManager = require('./mediawiki.TokenTransformManager.js')
.AttributeTransformManager,
defines = require('./mediawiki.parser.defines.js');
function TemplateHandler ( manager ) {
this.reset();
this.register( manager );
this.parserFunctions = new ParserFunctions( manager );
}
TemplateHandler.prototype.reset = function ( token ) {
return {token: token};
};
// constants
TemplateHandler.prototype.rank = 1.1;
TemplateHandler.prototype.register = function ( manager ) {
this.manager = manager;
// Register for template and templatearg tag tokens
manager.addTransform( this.onTemplate.bind(this),
this.rank, 'tag', 'template' );
// Template argument expansion
manager.addTransform( this.onTemplateArg.bind(this),
this.rank, 'tag', 'templatearg' );
};
/**
* Main template token handler
*
* Expands target and arguments (both keys and values) and either directly
* calls or sets up the callback to _expandTemplate, which then fetches and
* processes the template.
*/
TemplateHandler.prototype.onTemplate = function ( token, frame, cb ) {
//console.log('onTemplate! ' + JSON.stringify( token, null, 2 ) +
// ' args: ' + JSON.stringify( this.manager.args ));
// create a new temporary frame for argument and title expansions
var tplExpandData = {
args: {},
manager: this.manager,
cb: cb,
origToken: token,
resultTokens: [],
attribsAsync: true,
overallAsync: false,
expandDone: false
},
transformCB,
i = 0,
res;
var attributes = [token.attribs.shift()];
if( token.attribs.length ) {
attributes = attributes.concat( this._nameArgs( token.attribs ) );
}
this.manager.env.dp( 'before AttributeTransformManager: ' +
JSON.stringify( attributes, null, 2 ) );
new AttributeTransformManager(
this.manager,
this._returnAttributes.bind( this, tplExpandData )
).process( attributes );
// Unblock finish
if ( ! tplExpandData.attribsAsync ) {
// Attributes were transformed synchronously
this.manager.env.dp (
'sync attribs for ' + JSON.stringify( tplExpandData.target ),
tplExpandData.expandedArgs
);
// All attributes are fully expanded synchronously (no IO was needed)
return this._expandTemplate ( tplExpandData );
} else {
// Async attribute expansion is going on
this.manager.env.dp( 'async return for ' + JSON.stringify( token ));
tplExpandData.overallAsync = true;
return { async: true };
}
};
/**
* Create positional (number) keys for arguments without explicit keys
*/
TemplateHandler.prototype._nameArgs = function ( attribs ) {
var n = 1,
out = [];
for ( var i = 0, l = attribs.length; i < l; i++ ) {
// FIXME: Also check for whitespace-only named args!
if ( ! attribs[i].k.length ) {
out.push( {k: [ n.toString() ], v: attribs[i].v } );
n++;
} else {
out.push( attribs[i] );
}
}
this.manager.env.dp( '_nameArgs: ' + JSON.stringify( out ) );
return out;
};
/**
* Callback for argument (including target) expansion in AttributeTransformManager
*/
TemplateHandler.prototype._returnAttributes = function ( tplExpandData,
attributes )
{
this.manager.env.dp( 'TemplateHandler._returnAttributes: ' + JSON.stringify(attributes) );
// Remove the target from the attributes
tplExpandData.attribsAsync = false;
tplExpandData.target = attributes[0].v;
attributes.shift();
tplExpandData.expandedArgs = attributes;
if ( tplExpandData.overallAsync ) {
this._expandTemplate ( tplExpandData );
}
};
/**
* Fetch, tokenize and token-transform a template after all arguments and the
* target were expanded.
*/
TemplateHandler.prototype._expandTemplate = function ( tplExpandData ) {
//console.log('TemplateHandler.expandTemplate: ' +
// JSON.stringify( tplExpandData, null, 2 ) );
var res;
if ( ! tplExpandData.target ) {
this.manager.env.dp( 'No target! ' +
JSON.stringify( tplExpandData, null, 2 ) );
console.trace();
}
// TODO:
// check for 'subst:'
// check for variable magic names
// check for msg, msgnw, raw magics
// check for parser functions
// First, check the target for loops
var target = this.manager.env.tokensToString( tplExpandData.target ).trim();
var args = this.manager.env.KVtoHash( tplExpandData.expandedArgs );
this.manager.env.dp( 'argHash: ', args );
var prefix = target.split(':', 1)[0].toLowerCase().trim();
if ( prefix && 'pf_' + prefix in this.parserFunctions ) {
var funcArg = target.substr( prefix.length + 1 );
this.manager.env.tp( 'func prefix: ' + prefix +
' args=' + JSON.stringify( tplExpandData.expandedArgs, null, 2) +
' funcArg=' + funcArg);
//this.manager.env.dp( 'entering prefix', funcArg, args );
res = this.parserFunctions[ 'pf_' + prefix ]( funcArg,
tplExpandData.expandedArgs, args );
// XXX: support async parser functions!
if ( tplExpandData.overallAsync ) {
this.manager.env.dp( 'TemplateHandler._expandTemplate: calling back ' +
'after parser func ' + prefix + ' with res:' + JSON.stringify( res ) );
return tplExpandData.cb( res, false );
} else {
this.manager.env.dp( 'TemplateHandler._expandTemplate: sync return ' +
'after parser func ' + prefix + ' with res:' + JSON.stringify( res ) );
return { tokens: res };
//data.reset();
}
}
this.manager.env.tp( 'template target: ' + target );
// now normalize the target before template processing
target = this.manager.env.normalizeTitle( target );
var checkRes = this.manager.loopAndDepthCheck.check( target, this.manager.env.maxDepth );
if( checkRes ) {
// Loop detected or depth limit exceeded, abort!
res = [
checkRes,
new TagTk( 'a', [{k: 'href', v: target}] ),
target,
new EndTagTk( 'a' )
];
if ( tplExpandData.overallAsync ) {
return tplExpandData.cb( res, false );
} else {
return { tokens: res };
}
}
// Get a nested transformation pipeline for the input type. The input
// pipeline includes the tokenizer, synchronous stage-1 transforms for
// 'text/wiki' input and asynchronous stage-2 transforms).
var inputPipeline = this.manager.newChildPipeline(
this.manager.inputType || 'text/wiki',
args,
tplExpandData.target
);
// Hook up the inputPipeline output events to our handlers
inputPipeline.addListener( 'chunk', this._onChunk.bind ( this, tplExpandData ) );
inputPipeline.addListener( 'end', this._onEnd.bind ( this, tplExpandData ) );
// Resolve a possibly relative link
var templateName = this.manager.env.resolveTitle(
target,
'Template'
);
// XXX: notes from brion's mediawiki.parser.environment
// resolve template name
// load template w/ canonical name
// load template w/ variant names (language variants)
// For now, just fetch the template and pass the callback for further
// processing along.
this._fetchTemplateAndTitle(
templateName,
this._processTemplateAndTitle.bind( this, inputPipeline ),
tplExpandData
);
// If nothing was async so far and the template source was retrieved and
// fully processed without async requests (using the cache), then
// expandDone is set to true in our _onEnd handler.
if ( tplExpandData.overallAsync ||
! tplExpandData.expandDone ) {
tplExpandData.overallAsync = true;
this.manager.env.dp( 'Async return from _expandTemplate for ' +
JSON.stringify ( tplExpandData.target ) );
return { async: true };
} else {
this.manager.env.dp( 'Sync return from _expandTemplate for ' +
JSON.stringify( tplExpandData.target ) + ' : ' +
JSON.stringify( tplExpandData.result )
);
return tplExpandData.result;
}
};
/**
* Handle chunk emitted from the input pipeline after feeding it a template
*/
TemplateHandler.prototype._onChunk = function( tplExpandData, chunk ) {
// We encapsulate the output by default, so collect tokens here.
this.manager.env.dp( 'TemplateHandler._onChunk' + JSON.stringify( chunk ) );
tplExpandData.resultTokens = tplExpandData.resultTokens.concat( chunk );
};
/**
* Handle the end event emitted by the parser pipeline after fully processing
* the template source.
*/
TemplateHandler.prototype._onEnd = function( tplExpandData, token ) {
this.manager.env.dp( 'TemplateHandler._onEnd' + JSON.stringify( tplExpandData.resultTokens ) );
tplExpandData.expandDone = true;
var res = tplExpandData.resultTokens;
// Strip 'end' tokens and trailing newlines
var l = res[res.length - 1];
while ( res.length &&
( l.type === 'END' || l.constructor === NlTk )
)
{
this.manager.env.dp( 'TemplateHandler, stripping end or whitespace tokens' );
res.pop();
l = res[res.length - 1];
}
// Could also encapsulate the template tokens here, if that turns out
// better for the editor.
//console.log( 'TemplateHandler._onEnd: ' + JSON.stringify( res, null, 2 ) );
if ( tplExpandData.overallAsync ) {
this.manager.env.dp( 'TemplateHandler._onEnd: calling back with res:' +
JSON.stringify( res ) );
tplExpandData.cb( res, false );
} else {
this.manager.env.dp( 'TemplateHandler._onEnd: synchronous return!' );
tplExpandData.result = { tokens: res };
//data.reset();
}
};
/**
* Process a fetched template source
*/
TemplateHandler.prototype._processTemplateAndTitle = function( pipeline, src, title ) {
// Feed the pipeline. XXX: Support different formats.
this.manager.env.dp( 'TemplateHandler._processTemplateAndTitle: ' + src );
pipeline.process ( src );
};
/**
* Fetch a template
*/
TemplateHandler.prototype._fetchTemplateAndTitle = function ( title, callback, tplExpandData ) {
// @fixme normalize name?
var self = this;
if ( title in this.manager.env.pageCache ) {
// Unwind the stack
process.nextTick(
function () {
callback( self.manager.env.pageCache[title], title );
}
);
} else if ( ! this.manager.env.fetchTemplates ) {
callback( 'Warning: Page/template fetching disabled, and no cache for ' +
title, title );
} else {
// We are about to start an async request for a template, so mark this
// template expansion as such.
tplExpandData.overallAsync = true;
this.manager.env.dp( 'Note: trying to fetch ' + title );
// Start a new request if none is outstanding
this.manager.env.dp( 'requestQueue: ', this.manager.env.requestQueue);
if ( this.manager.env.requestQueue[title] === undefined ) {
this.manager.env.tp( 'Note: Starting new request for ' + title );
this.manager.env.requestQueue[title] = new TemplateRequest( this.manager, title );
}
// Append a listener to the request
this.manager.env.requestQueue[title].once( 'src', callback );
}
};
/*********************** Template argument expansion *******************/
/**
* Expand template arguments with tokens from the containing frame.
*/
TemplateHandler.prototype.onTemplateArg = function ( token, frame, cb ) {
token.resultTokens = false;
new AttributeTransformManager (
this.manager,
this._returnArgAttributes.bind( this, token, cb, frame )
).process( token.attribs );
if ( token.resultTokens !== false ) {
// synchronous return
//console.log( 'synchronous attribute expand: ' + JSON.stringify( token.resultTokens ) );
return { tokens: token.resultTokens };
} else {
//console.log( 'asynchronous attribute expand: ' + JSON.stringify( token, null, 2 ) );
// asynchronous return
token.resultTokens = [];
return { async: true };
}
};
TemplateHandler.prototype._returnArgAttributes = function ( token, cb, frame, attributes ) {
//console.log( '_returnArgAttributes: ' + JSON.stringify( attributes ));
var argName = this.manager.env.tokensToString( attributes[0].v ).trim(),
res;
if ( argName in this.manager.args ) {
// return tokens for argument
//console.log( 'templateArg found: ' + argName +
// ' vs. ' + JSON.stringify( this.manager.args ) );
res = this.manager.args[argName];
} else {
var defaultValue = (attributes[1] && ! attributes[1].k.length && attributes[1].v) || false;
this.manager.env.dp( 'templateArg not found: ' + argName +
' vs. ' + JSON.stringify( defaultValue ) );
if ( defaultValue ) {
res = defaultValue;
} else {
res = [ '{{{' + argName + '}}}' ];
}
}
if ( token.resultTokens !== false ) {
cb( res );
} else {
token.resultTokens = res;
}
};
/***************** Template fetch request helper class ********/
function TemplateRequest ( manager, title ) {
// Increase the number of maximum listeners a bit..
this.setMaxListeners( 10000 );
var self = this,
url = manager.env.wgScriptPath + '/api' +
manager.env.wgScriptExtension +
'?' +
qs.stringify( {
format: 'json',
action: 'query',
prop: 'revisions',
rvprop: 'content',
titles: title
} );
//'?format=json&action=query&prop=revisions&rvprop=content&titles=' + title;
request({
method: 'GET',
followRedirect: true,
url: url,
headers: {
'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:9.0.1) ' +
'Gecko/20100101 Firefox/9.0.1 Iceweasel/9.0.1'
}
},
function (error, response, body) {
//console.log( 'response for ' + title + ' :' + body + ':' );
if(error) {
manager.env.dp(error);
self.emit('src', 'Page/template fetch failure for title ' + title, title);
} else if(response.statusCode == 200) {
var src = '',
data,
normalizedTitle;
try {
//console.log( 'body: ' + body );
data = JSON.parse( body );
} catch(e) {
console.log( "Error: while parsing result. Error was: " );
console.log( e );
console.log( "Response that didn't parse was:");
console.log( "------------------------------------------\n" + body );
console.log( "------------------------------------------" );
}
try {
$.each( data.query.pages, function(i, page) {
if (page.revisions && page.revisions.length) {
src = page.revisions[0]['*'];
normalizeTitle = page.title;
}
});
} catch ( e2 ) {
console.log( 'Did not find page revisions in the returned body:' + body );
src = '';
}
//console.log( 'Page ' + title + ': got ' + src );
manager.env.tp( 'Retrieved ' + title );
manager.env.pageCache[title] = src;
self.emit( 'src', src, title );
}
// XXX: handle other status codes
// Remove self from request queue
manager.env.dp( 'trying to remove ' + title + ' from requestQueue' );
delete manager.env.requestQueue[title];
manager.env.dp( 'after deletion:', manager.env.requestQueue );
});
}
/*
* XXX: The jQuery version does not quite work with node, but we keep
* it around for now.
$.ajax({
url: url,
data: {
format: 'json',
action: 'query',
prop: 'revisions',
rvprop: 'content',
titles: title
},
success: function(data, statusString, xhr) {
console.log( 'Page ' + title + ' success ' + JSON.stringify( data ) );
var src = null, title = null;
$.each(data.query.pages, function(i, page) {
if (page.revisions && page.revisions.length) {
src = page.revisions[0]['*'];
title = page.title;
}
});
if (typeof src !== 'string') {
console.log( 'Page ' + title + 'not found! Got ' + src );
callback( 'Page ' + title + ' not found' );
} else {
// Add to cache
console.log( 'Page ' + title + ': got ' + src );
this.manager.env.pageCache[title] = src;
callback(src, title);
}
},
error: function(xhr, msg, err) {
console.log( 'Page/template fetch failure for title ' +
title + ', url=' + url + JSON.stringify(xhr) + ', err=' + err );
callback('Page/template fetch failure for title ' + title);
},
dataType: 'json',
cache: false, // @fixme caching, versions etc?
crossDomain: true
});
*/
// Inherit from EventEmitter
TemplateRequest.prototype = new events.EventEmitter();
TemplateHandler.prototype.constructor = TemplateRequest;
if (typeof module == "object") {
module.exports.TemplateHandler = TemplateHandler;
}