Files
meteor/packages/minimongo/modify.js
2012-02-16 22:41:16 -08:00

296 lines
9.3 KiB
JavaScript

// XXX need a strategy for passing the binding of $ into this
// function, from the compiled selector
//
// maybe just {key.up.to.just.before.dollarsign: array_index}
//
// XXX atomicity: if one modification fails, do we roll back the whole
// change?
LocalCollection._modify = function (doc, mod) {
var is_modifier = false;
for (var k in mod) {
// IE7 doesn't support indexing into strings (eg, k[0]), so use substr.
// Too bad -- it's far slower:
// http://jsperf.com/testing-the-first-character-of-a-string
is_modifier = k.substr(0, 1) === '$';
break; // just check the first key.
}
var new_doc;
if (!is_modifier) {
if (mod._id && doc._id !== mod._id)
throw Error("Cannot change the _id of a document");
// replace the whole document
for (var k in mod) {
if (k.substr(0, 1) === '$')
throw Error("Field name may not start with '$'");
if (/\./.test(k))
throw Error("Field name may not contain '.'");
}
new_doc = mod;
} else {
// apply modifiers
var new_doc = LocalCollection._deepcopy(doc);
for (var op in mod) {
var mod_func = LocalCollection._modifiers[op];
if (!mod_func)
throw Error("Invalid modifier specified " + op);
for (var keypath in mod[op]) {
// XXX mongo doesn't allow mod field names to end in a period,
// but I don't see why.. it allows '' as a key, as does JS
if (keypath.length && keypath[keypath.length-1] === '.')
throw Error("Invalid mod field name, may not end in a period");
var arg = mod[op][keypath];
var keyparts = keypath.split('.');
var no_create = !!LocalCollection._noCreateModifiers[op];
var forbid_array = (op === "$rename");
var target = LocalCollection._findModTarget(new_doc, keyparts,
no_create, forbid_array);
var field = keyparts.pop();
mod_func(target, field, arg, keypath, new_doc);
}
}
}
// move new document into place
for (var k in doc) {
if (k !== '_id')
delete doc[k];
}
for (var k in new_doc) {
doc[k] = new_doc[k];
}
};
// for a.b.c.2.d.e, keyparts should be ['a', 'b', 'c', '2', 'd', 'e'],
// and then you would operate on the 'e' property of the returned
// object. if no_create is falsey, creates intermediate levels of
// structure as necessary, like mkdir -p (and raises an exception if
// that would mean giving a non-numeric property to an array.) if
// no_create is true, return undefined instead. may modify the last
// element of keyparts to signal to the caller that it needs to use a
// different value to index into the returned object (for example,
// ['a', '01'] -> ['a', 1]). if forbid_array is true, return null if
// the keypath goes through an array.
LocalCollection._findModTarget = function (doc, keyparts, no_create,
forbid_array) {
for (var i = 0; i < keyparts.length; i++) {
var last = (i === keyparts.length - 1);
var keypart = keyparts[i];
var numeric = /^[0-9]+$/.test(keypart);
if (no_create && (!(typeof doc === "object") || !(keypart in doc)))
return undefined;
if (doc instanceof Array) {
if (forbid_array)
return null;
if (!numeric)
throw Error("can't append to array using string field name ["
+ keypart + "]");
keypart = parseInt(keypart);
if (last)
// handle 'a.01'
keyparts[i] = keypart;
while (doc.length < keypart)
doc.push(null);
if (!last) {
if (doc.length === keypart)
doc.push({});
else if (typeof doc[keypart] !== "object")
throw Error("can't modify field '" + keyparts[i + 1] +
"' of list value " + JSON.stringify(doc[keypart]));
}
} else {
// XXX check valid fieldname (no $ at start, no .)
if (!last && !(keypart in doc))
doc[keypart] = {};
}
if (last)
return doc;
doc = doc[keypart];
}
// notreached
};
LocalCollection._noCreateModifiers = {
$unset: true,
$pop: true,
$rename: true,
$pull: true,
$pullAll: true
};
LocalCollection._modifiers = {
$inc: function (target, field, arg) {
if (typeof arg !== "number")
throw Error("Modifier $inc allowed for numbers only");
if (field in target) {
if (typeof target[field] !== "number")
throw Error("Cannot apply $inc modifier to non-number");
target[field] += arg;
} else {
target[field] = arg;
}
},
$set: function (target, field, arg) {
target[field] = LocalCollection._deepcopy(arg);
},
$unset: function (target, field, arg) {
if (target !== undefined) {
if (target instanceof Array) {
if (field in target)
target[field] = null;
} else
delete target[field];
}
},
$push: function (target, field, arg) {
var x = target[field];
if (x === undefined)
target[field] = [arg];
else if (!(x instanceof Array))
throw Error("Cannot apply $push modifier to non-array");
else
x.push(LocalCollection._deepcopy(arg));
},
$pushAll: function (target, field, arg) {
if (!(typeof arg === "object" && arg instanceof Array))
throw Error("Modifier $pushAll/pullAll allowed for arrays only");
var x = target[field];
if (x === undefined)
target[field] = arg;
else if (!(x instanceof Array))
throw Error("Cannot apply $pushAll modifier to non-array");
else {
for (var i = 0; i < arg.length; i++)
x.push(arg[i]);
}
},
$addToSet: function (target, field, arg) {
var x = target[field];
if (x === undefined)
target[field] = [arg];
else if (!(x instanceof Array))
throw Error("Cannot apply $addToSet modifier to non-array");
else {
var isEach = false;
if (typeof arg === "object") {
for (var k in arg) {
if (k === "$each")
isEach = true;
break;
}
}
var values = isEach ? arg["$each"] : [arg];
_.each(values, function (value) {
for (var i = 0; i < x.length; i++)
if (LocalCollection._f._equal(value, x[i]))
return;
x.push(value);
});
}
},
$pop: function (target, field, arg) {
if (target === undefined)
return;
var x = target[field];
if (x === undefined)
return;
else if (!(x instanceof Array))
throw Error("Cannot apply $pop modifier to non-array");
else {
if (typeof arg === 'number' && arg < 0)
x.splice(0, 1);
else
x.pop();
}
},
$pull: function (target, field, arg) {
if (target === undefined)
return;
var x = target[field];
if (x === undefined)
return;
else if (!(x instanceof Array))
throw Error("Cannot apply $pull/pullAll modifier to non-array");
else {
var out = []
if (typeof arg === "object" && !(arg instanceof Array)) {
// XXX would be much nicer to compile this once, rather than
// for each document we modify.. but usually we're not
// modifying that many documents, so we'll let it slide for
// now
// XXX _compileSelector isn't up for the job, because we need
// to permit stuff like {$pull: {a: {$gt: 4}}}.. something
// like {$gt: 4} is not normally a complete selector.
// same issue as $elemMatch possibly?
var match = LocalCollection._compileSelector(arg);
for (var i = 0; i < x.length; i++)
if (!match(x[i]))
out.push(x[i])
} else {
for (var i = 0; i < x.length; i++)
if (!LocalCollection._f._equal(x[i], arg))
out.push(x[i]);
}
target[field] = out;
}
},
$pullAll: function (target, field, arg) {
if (!(typeof arg === "object" && arg instanceof Array))
throw Error("Modifier $pushAll/pullAll allowed for arrays only");
if (target === undefined)
return;
var x = target[field];
if (x === undefined)
return;
else if (!(x instanceof Array))
throw Error("Cannot apply $pull/pullAll modifier to non-array");
else {
var out = []
for (var i = 0; i < x.length; i++) {
var exclude = false;
for (var j = 0; j < arg.length; j++) {
if (LocalCollection._f._equal(x[i], arg[j])) {
exclude = true;
break;
}
}
if (!exclude)
out.push(x[i]);
}
target[field] = out;
}
},
$rename: function (target, field, arg, keypath, doc) {
if (keypath === arg)
// no idea why mongo has this restriction..
throw Error("$rename source must differ from target");
if (target === null)
throw Error("$rename source field invalid");
if (typeof arg !== "string")
throw Error("$rename target must be a string");
if (target === undefined)
return;
var v = target[field];
delete target[field];
var keyparts = arg.split('.');
var target2 = LocalCollection._findModTarget(doc, keyparts, false, true);
if (target2 === null)
throw Error("$rename target field invalid");
var field2 = keyparts.pop();
target2[field2] = v;
},
$bit: function (target, field, arg) {
// XXX mongo only supports $bit on integers, and we only support
// native javascript numbers (doubles) so far, so we can't support $bit
throw Error("$bit is not supported");
}
};