Fix up variable references after deserializing a .sprite2 or .sprite3 to avoid conflicts with pre-existing variables.

This commit is contained in:
Karishma Chadha 2018-06-19 14:02:54 -04:00
parent 5cc48b6ef3
commit f2aacbc79c
4 changed files with 162 additions and 33 deletions

View file

@ -6,6 +6,8 @@ const Clone = require('../util/clone');
const {Map} = require('immutable');
const BlocksExecuteCache = require('./blocks-execute-cache');
const log = require('../util/log');
const Variable = require('./variable');
const StringUtil = require('../util/string-util');
/**
* @fileoverview
@ -670,6 +672,68 @@ class Blocks {
this.resetCache();
}
/**
* Fixes up variable references in this blocks container avoiding conflicts with
* pre-existing variables in the same scope.
* This is used when uploading a new sprite (the given target)
* into an existing project, where the new sprite may contain references
* to variable names that already exist as global variables in the project
* (and thus are in scope for variable references in the given sprite).
*
* If the given target has a block that references an existing global variable and that
* variable *does not* exist in the target itself (e.g. it was a global variable in the
* project the sprite was originally exported from), fix the variable references in this sprite
* to reference the id of the pre-existing global variable.
* If the given target has a block that references an existing global variable and that
* variable does exist in the target itself (e.g. it's a local variable in the sprite being uploaded),
* then the variable is renamed to distinguish itself from the pre-existing variable.
* All blocks that reference the local variable will be updated to use the new name.
* @param {Target} target The new target being uploaded, with potential variable conflicts
* @param {Runtime} runtime The runtime context with any pre-existing variables
*/
fixUpVariableReferences (target, runtime) {
const blocks = this._blocks;
for (const blockId in blocks) {
let varOrListField = null;
let varType = null;
if (blocks[blockId].fields.VARIABLE) {
varOrListField = blocks[blockId].fields.VARIABLE;
varType = Variable.SCALAR_TYPE;
} else if (blocks[blockId].fields.LIST) {
varOrListField = blocks[blockId].fields.LIST;
varType = Variable.LIST_TYPE;
}
if (varOrListField) {
const currVarId = varOrListField.id;
const currVarName = varOrListField.value;
if (target.lookupVariableById(currVarId)) {
// Found a variable with the id in either the target or the stage,
// figure out which one.
if (target.variables.hasOwnProperty(currVarId)) {
// If the target has the variable, then check whether the stage
// has one with the same name and type. If it does, then rename
// this target specific variable so that there is a distinction.
const stage = runtime.getTargetForStage();
if (stage && stage.variables &&
stage.lookupVariableByNameAndType(currVarName, varType)) {
// TODO what should the new name be?
const newName = StringUtil.unusedName(
`${target.getName()}_${currVarName}`,
target.getAllVariableNamesInScopeByType(varType));
target.renameVariable(currVarId, newName);
this.updateBlocksAfterVarRename(currVarId, newName);
}
}
} else {
const existingVar = target.lookupVariableByNameAndType(currVarName, varType);
if (existingVar) {
varOrListField.id = existingVar.id;
}
}
}
}
}
/**
* Keep blocks up to date after a variable gets renamed.
* @param {string} varId The id of the variable that was renamed

View file

@ -80,14 +80,40 @@ class Target extends EventEmitter {
}
/**
* Look up a variable object, and create it if one doesn't exist.
* Get the names of all the variables of the given type that are in scope for this target.
* For targets that are not the stage, this includes any target-specific
* variables as well as any stage variables.
* For the stage, this is all stage variables.
* @param {string} type The variable type to search for; defaults to Variable.SCALAR_TYPE
* @return {Array<string>} A list of variable names
*/
getAllVariableNamesInScopeByType (type) {
if (typeof type !== 'string') type = Variable.SCALAR_TYPE;
const targetVariables = Object.values(this.variables)
.filter(v => v.type === type)
.map(variable => variable.name);
if (this.isStage || !this.runtime) {
return targetVariables;
}
const stage = this.runtime.getTargetForStage();
const stageVariables = stage.getAllVariableNamesInScopeByType(type);
return targetVariables.concat(stageVariables);
}
/**
* Look up a variable object, first by id, and then by name if the id is not found.
* Create a new variable if both lookups fail.
* @param {string} id Id of the variable.
* @param {string} name Name of the variable.
* @return {!Variable} Variable object.
*/
lookupOrCreateVariable (id, name) {
const variable = this.lookupVariableById(id);
let variable = this.lookupVariableById(id);
if (variable) return variable;
variable = this.lookupVariableByNameAndType(name, Variable.SCALAR_TYPE);
if (variable) return variable;
// No variable with this name exists - create it locally.
const newVariable = new Variable(id, name, Variable.SCALAR_TYPE, false);
this.variables[id] = newVariable;
@ -161,6 +187,40 @@ class Target extends EventEmitter {
}
}
/**
* Look up a variable object by its name and variable type.
* Search begins with local variables; then global variables if a local one
* was not found.
* @param {string} name Name of the variable.
* @param {string} type Type of the variable. Defaults to Variable.SCALAR_TYPE.
* @return {?Variable} Variable object if found, or null if not.
*/
lookupVariableByNameAndType (name, type) {
if (typeof name !== 'string') return;
if (typeof type !== 'string') type = Variable.SCALAR_TYPE;
for (const varId in this.variables) {
const currVar = this.variables[varId];
if (currVar.name === name && currVar.type === type) {
return currVar;
}
}
if (this.runtime && !this.isStage) {
const stage = this.runtime.getTargetForStage();
if (stage) {
for (const varId in stage.variables) {
const currVar = stage.variables[varId];
if (currVar.name === name && currVar.type === type) {
return currVar;
}
}
}
}
return null;
}
/**
* Look up a list object for this target, and create it if one doesn't exist.
* Search begins for local lists; then look for globals.
@ -169,8 +229,12 @@ class Target extends EventEmitter {
* @return {!Varible} Variable object representing the found/created list.
*/
lookupOrCreateList (id, name) {
const list = this.lookupVariableById(id);
let list = this.lookupVariableById(id);
if (list) return list;
list = this.lookupVariableByNameAndType(name, Variable.LIST_TYPE);
if (list) return list;
// No variable with this name exists - create it locally.
const newList = new Variable(id, name, Variable.LIST_TYPE, false);
this.variables[id] = newList;
@ -240,11 +304,14 @@ class Target extends EventEmitter {
name: 'VARIABLE',
value: id
}, this.runtime);
const monitorBlock = blocks.getBlock(variable.id);
if (monitorBlock) {
this.runtime.requestUpdateMonitor(Map({
id: id,
params: blocks._getBlockParams(blocks.getBlock(variable.id))
params: blocks._getBlockParams(monitorBlock)
}));
}
}
}
}

View file

@ -189,19 +189,14 @@ const parseScripts = function (scripts, blocks, addBroadcastMsg, getVariableId,
* Create a callback for assigning fixed IDs to imported variables
* Generator stores the global variable mapping in a closure
* @param {!string} targetId the id of the target to scope the variable to
* @param {object=} initialVars Initial vars in scope if parsing a sprite
* @return {string} variable ID
*/
const generateVariableIdGetter = (function () {
let globalVariableNameMap = {};
const namer = (targetId, name) => `${targetId}-${name}`;
return function (targetId, topLevel, initialVars) {
return function (targetId, topLevel) {
// Reset the global variable map if topLevel
if (topLevel) {
globalVariableNameMap = {};
} else if (initialVars) {
globalVariableNameMap = initialVars;
}
if (topLevel) globalVariableNameMap = {};
return function (name) {
if (topLevel) { // Store the name/id pair in the globalVariableNameMap
globalVariableNameMap[name] = namer(targetId, name);
@ -339,10 +334,9 @@ const parseMonitorObject = (object, runtime, targets, extensions) => {
* @param {ImportedExtensionsInfo} extensions - (in/out) parsed extension information will be stored here.
* @param {boolean} topLevel - Whether this is the top-level object (stage).
* @param {?object} zip - Optional zipped assets for local file import
* @param {object=} initialVarScope - Initial set of variables in scope if parsing a single sprite
* @return {!Promise.<Array.<Target>>} Promise for the loaded targets when ready, or null for unsupported objects.
*/
const parseScratchObject = function (object, runtime, extensions, topLevel, zip, initialVarScope) {
const parseScratchObject = function (object, runtime, extensions, topLevel, zip) {
if (!object.hasOwnProperty('objName')) {
if (object.hasOwnProperty('listName')) {
// Shim these objects so they can be processed as monitors
@ -433,7 +427,7 @@ const parseScratchObject = function (object, runtime, extensions, topLevel, zip,
// Create the first clone, and load its run-state from JSON.
const target = sprite.createClone(topLevel ? StageLayering.BACKGROUND_LAYER : StageLayering.SPRITE_LAYER);
const getVariableId = generateVariableIdGetter(target.id, topLevel, initialVarScope);
const getVariableId = generateVariableIdGetter(target.id, topLevel);
const globalBroadcastMsgObj = globalBroadcastMsgStateGenerator(topLevel);
const addBroadcastMsg = globalBroadcastMsgObj.broadcastMsgMapUpdater;
@ -673,18 +667,14 @@ const sb2import = function (json, runtime, optForceSprite, zip) {
extensionURLs: new Map()
};
const initialGlobalVars = {};
if (optForceSprite && runtime.targets && runtime.getTargetForStage()) {
const stageVars = runtime.getTargetForStage().variables;
for (const varId in stageVars) {
const currVar = stageVars[varId];
initialGlobalVars[currVar.name] = varId;
return parseScratchObject(json, runtime, extensions, !optForceSprite, zip)
.then(targets => {
if (optForceSprite && targets.length === 1) {
const target = targets[0];
target.blocks.fixUpVariableReferences(target, runtime);
}
}
// If parsing a sprite, use the current global vars as parent scope for the sprite
return parseScratchObject(json, runtime, extensions, !optForceSprite, zip,
(optForceSprite ? initialGlobalVars : null))
return targets;
})
.then(targets => ({
targets,
extensions

View file

@ -936,7 +936,15 @@ const deserialize = function (json, runtime, zip, isSingleSprite) {
return Promise.all(
((isSingleSprite ? [json] : json.targets) || []).map(target =>
parseScratchObject(target, runtime, extensions, zip))
).then(targets => ({
)
.then(targets => {
if (isSingleSprite && targets.length === 1) {
const target = targets[0];
target.blocks.fixUpVariableReferences(target, runtime);
}
return targets;
})
.then(targets => ({
targets,
extensions
}));