Is it possible to specify MXML-esque "binding strings" in ActionScript?
For example, I want to be able to do something like:
MXMLBinding(this, "first_item",
this, "{myArrayCollection.getItemAt(0)");
MXMLBinding(this, ["nameLbl", "text"],
this, "Name: {somePerson.first} {somePerson.last}");
Edit: thanks for the responses and suggestions… Basically, it seems like you can't do this. I've dug around and figured out why.
(Shameless plug)
BindageTools can do this:
Bind.fromProperty(this, "myArrayCollection", itemAt(0))
.toProperty(this, "first_item");
Bind.fromAll(
Bind.fromProperty(this, "somePerson.first"),
Bind.fromProperty(this, "somePerson.last")
)
.format("Name: {0} {1}")
.toProperty(this, "nameLbl.text");
Note that BindageTools puts the source object first and the destination last (whereas BindingUtils puts the destination first and the source last).
Using ChangeWatcher (e.g., via BindingUtils.bindProperty or .bindSetter) is the way to go, yes. I admit it's a strange notation, but once you get used to it, it makes sense, works perfectly and is quite flexible, too.
Of course, you could always wrap those functions yourself somehow, if the notation bugged you -- both methods are static, so doing so in a way that feels more appropriate to your application should be a fairly straightforward exercise.
I could use BindingUtils or ChainWatcher, but then I'd end up with code that looks something like this:
…
BindingUtils.bindSetter(updateName, this, ["somePerson", "first"]);
BindingUtils.bindSetter(updateName, this, ["somePerson", "last"]);
…
protected function updateName(...ignored):void {
this.nameLbl.text = "Name: " + somePerson.first + " " + somePerson.last;
}
Which is just a little bit ugly… And the first example, binding to arrayCollection.getItemAt(0), is even worse.
Does the first parameter (function) of BindingUtils.bindSetter method accept anonymous methods?
BindingUtils.bindSetter(function()
{
this.nameLbl.text = "Name: " + somePerson.first + " " + somePerson.last;
}, this, ["somePerson", "last"]);
I hate anonymous methods and obviously it's even more uglier - so I won't recommend that even if it works, but just wondering if it works.
Never the answer anyone wants to hear, but just manage this stuff with getters/setters in ActionScript. With a proper MVC, it's dead simple to manually set your display fields.
public function set myArrayCollection(value:Array):void {
myAC = new ArrayCollection(value);
first_item = mcAC.getItemAt(0); // or value[0];
}
etc....
Alright, so I've done some digging, and here's what's up.
Bindings in MXML are, contrary to reason, setup by Java code (modules/compiler/src/java/flex2/compiler/as3/binding/DataBindingFirstPassEvaluator.java, if I'm not mistaken) at compile time.
For example, the binding: first_item="{myArrayCollection.getItemAt(0)}"` is expanded into, among other things, this:
// writeWatcher id=0 shouldWriteSelf=true class=flex2.compiler.as3.binding.PropertyWatcher shouldWriteChildren=true
watchers[0] = new mx.binding.PropertyWatcher("foo",
{ propertyChange: true }, // writeWatcherListeners id=0 size=1
[ bindings[0] ],
propertyGetter);
// writeWatcher id=1 shouldWriteSelf=true class=flex2.compiler.as3.binding.FunctionReturnWatcher shouldWriteChildren=true
watchers[1] = new mx.binding.FunctionReturnWatcher("getItemAt",
target,
function():Array { return [ 0 ]; },
{ collectionChange: true },
[bindings[0]],
null);
// writeWatcherBottom id=0 shouldWriteSelf=true class=flex2.compiler.as3.binding.PropertyWatcher
watchers[0].updateParent(target);
// writeWatcherBottom id=1 shouldWriteSelf=true class=flex2.compiler.as3.binding.FunctionReturnWatcher
// writeEvaluationWatcherPart 1 0 parentWatcher
watchers[1].parentWatcher = watchers[0];
watchers[0].addChild(watchers[1]);
This means that it is simply impossible to setup curly-brace MXML-style bindings at runtime because the code to do it does not exist in ActionScript.
Related
I'm trying to use SequenceReader<T> in .Net Core Preview 8 to parse Guacamole Protocol network traffic.
The traffic might look as follows:
5.error,14.some text here,1.0;
This is a single error instruction. There are 3 fields:
OpCode = error
Reason = some text here
Status = 0 (see Status Codes)
The fields are comma delimited (semi-colon terminated), but they also have the length prefixed on each field. I presume that's so that you could parse something like:
5.error,24.some, text, with, commas,1.0;
To produce Reason = some, text, with, commas.
Simple comma delimited parsing is simple enough to do (with or without SequenceReader). However, to utilise the length I've tried the following:
public static bool TryGetNextElement(this ref SerializationContext context, out ReadOnlySequence<byte> element)
{
element = default;
var start = context.Reader.Position;
if (!context.Reader.TryReadTo(out ReadOnlySequence<byte> lengthSlice, Utf8Bytes.Period, advancePastDelimiter: true))
return false;
if (!lengthSlice.TryGetInt(out var length))
return false;
context.Reader.Advance(length);
element = context.Reader.Sequence.Slice(start, context.Reader.Position);
return true;
}
Based on my understanding of the initial proposal, this should work, though also could be simplified I think because some of the methods in the proposal make life a bit easier than that which is available in .Net Core Preview 8.
However, the problem with this code is that the SequenceReader does not seem to Advance as I would expect. It's Position and Consumed properties remain unchanged when advancing, so the element I slice at the end is always an empty sequence.
What do I need to do in order to parse this protocol correctly?
I'm guessing that .Reader here is a property; this is important because SequenceReader<T> is a mutable struct, but every time you access .SomeProperty you are working with an isolated copy of the reader. It is fine to hide it behind a property, but you'd need to make sure you work with a local and then push back when complete, i.e.
var reader = context.Reader;
var start = reader.Position;
if (!reader.TryReadTo(out ReadOnlySequence<byte> lengthSlice,
Utf8Bytes.Period, advancePastDelimiter: true))
return false;
if (!lengthSlice.TryGetInt(out var length))
return false;
reader.Advance(length);
element = reader.Sequence.Slice(start, reader.Position);
context.Reader = reader; // update position
return true;
Note that a nice feature of this is that in the failure cases (return false), you won't have changed the state yet, because you've only been mutating your local standalone clone.
You could also consider a ref-return property for .Reader.
I would like to define a set of coding rules of a language structural proprietary language,
how can I proceed?
thank you very much
Some of your rules will be easy to deal with using only parsing. For example to find the number of lines in a function is not hard:
void function() : {
int firstLine, lastLine ; }
{
{firstLine = getToken(1).beginLine ; }
...
{lastLine = getToken(0).beginLine ; }
{check( lastLine - firstLine + 1 <= 150 ) ; }
}
Other rules, such as your example of nested ifs, will be best handled by traversing an abstract syntax tree. I'd suggest you look into JJTree. It supports visitors, which could be quite useful for encoding some of your rules.
If I have understood correctly,
in the file .jj, I have to add this function , which allows to check how many line of code in a method
or in the file parseur.java generated by javacc.
Let me introduce myself.
My name is Vladimir, C++ programmer, I am from Serbia. two weeks ago I have started to learn objective-C and it was fine until tonight.
Problem:
I cant remove double quotes from my NSLog output.
NSLog(#"The best singers:%#", list.best);
Strings are joined with componentsJoinedByString:#" and "
I would like to get something like this:
The best singers: Mickey and John.
But I get this:
The best singers: ("Mickey", and "John").
I cant remove comma (,) and parentheses either.
I have tried with "replaceOccurencesOfString" but with no success. It can remove any character except qoute and comma.
Also I have used -(NSString *)description method to return string.
You are getting the raw output from your list (which I assume is an array). You will have to do your own formatting to get this to display in the format that you want. You can achieve this by building your string by iterating through your array. Note that this probably isn't the most efficient nor the most robust way to achieve this.
NSMutableString *finalString = [NSMutableString string];
BOOL first = YES;
for (NSString *nameString in list) {
if (first) {
[finalString appendString:nameString];
first = NO;
} else {
[finalString appendString:[NSString stringWithFormat:#" and %#", nameString]];
}
}
We've got an odd issue occurring with ColdFusion on BlueDragon.NET. Asking here because of the broad experience of StackOverflow users.
Tags inside POSTed content to out BlueDragon.NET server gets removed, and we're not sure where in the stack it's getting removed. So for example if we post this data
[CORE]
Lesson_Status=Incomplete
Lesson_Location=comm_13_a02_bs_enus_t17s06v01
score=
time=00:00:56
[Core_Lesson]
<sd ac="" pc="7.0" at="1289834380459" ct="" ><t id="lo8" sc=";;" st="c" /></sd>
<sd ac='' pc='7.0' at='1289834380459' ct='' ><t id='lo8' sc=';;' st='c' /></sd>
<sd ac="" pc="7.0" at="1289834380459" ct="" ><t id="lo8" sc=";;" st="c" /></sd>
<sd ac="" pc="7.0" at="1289834380459" ct="" ><t id="lo8" sc=";;" st="c" /></sd>
<b>hello1</b>
<i>hello2</i>
<table border><td>hello3</td></table>
<sd>hello4</sd>
<sd ac="1">hello5</sd>
<t>hello6</t>
<t />
<t attr="hello8" />
<strong>hello10</strong>
<img>
><>
What we get back is this:
[CORE]
Lesson_Status=Incomplete
Lesson_Location=comm_13_a02_bs_enus_t17s06v01
score=
time=00:00:56
[Core_Lesson]
hello1
hello2
hello3
hello4
hello5
hello6
hello10
>
That is, anything that starts with < and ends with > is getting stripped or filtered and no longer appears in ColdFusion's FORM scope when it's posted.
Our server with BlueDragon JX does not suffer this problem.
If we bypass using the default FORM scope and use this code, the tag-like content appears:
<cfscript>
// get the content string of the raw HTTP headers, will include all POST content as a long querystring
RAWREQUEST = GetHttpRequestData();
// split the string on "&" character, each variable should now be separate
// note that at this point duplicate variables will get clobbered
RAWFORMFIELDS = ListToArray(RAWREQUEST.content, "&");
// We're creating a structure like "FORM", but better
BetterFORM = StructNew();
// Go over each of the raw form fields, take the key
// and add it as a key, and decode the value into the value field
// and trap the whole thing if for some reason garbage gets in there
for(i=1;i LTE ArrayLen(RAWFORMFIELDS);i = i + 1) {
temp = ListToArray(RAWFORMFIELDS[i], "=");
try {
tempkey = temp[1];
tempval = URLDecode(temp[2]);
StructInsert(BetterFORM, tempkey, tempval);
} catch(Any e) {
tempThisError = "Malformed Data: " & RAWFORMFIELDS[i];
// Log the value of tempThisError here?
// WriteOutput(tempThisError);
}
}
</cfscript>
<cfdump var="#BetterFORM#">
If we do this, and use the created BetterFORM variable, it's there, so it does not seem to be a problem with the requests being filtered at some other point in the stack. I was thinking maybe it was URLScan, but that appears not to be installed. Since BD.NET runs on .NET as the engine, perhaps there's some sanitization setting that is being used on all variables somehow?
Suggestions, ideas, etc are welcome on this issue.
I don't have a BD.NET instance handy to check, but Adobe ColdFusion has a setting in the cf administrator to strip "invalid tags". That's my best guess. Adobe CF replaces them with "invalidTag", my guess is that BD.Net just strips it silently.
It turned out to be very mundane.
We had a custom tag that did customized string replacements. On one server, it was modified to NOT replace all tags. On this server, we were using an older version that did. So the fault was not a difference between BlueDragon JX and BlueDragon.NET -- it was developer team error.
I am doing some labeling. I would like to add a resource key (s, sec) to one of my combo boxes with item[3sec, 5sec, 10sec, 30sec ...] and use it like:
Text="3<%$ Resources: myResource, s%>" to get comboBoxItem 3sec,
Text="5<%$ Resources: myResource, s%>" to get comboBoxItem 5sec ...
But I find that the server will treat this as plain text.
Do I need to define each item in a separate resource key pair?
Consider defining your resource file entry value as follows:
{0}sec
And then
String.Format(Resources.myResource.s, "3")
You can try creating your own custom expression builder. They are really powerful if you want to achieve what you have asked in your question.
Or, you can always do it using server-side code.
You could do it like this (with a DataBind() call somewhere):
Text='<%# "3" + Resources.myResource.s %>'
Edit: You can also do this from code behind. Something like this:
int[] times = new int[]{ 3, 5, 10, 30 };
foreach (int time in times)
{
string text = time.ToString() + Resources.myResource.s;
cbo.Items.Add(new ListItem(text, time.ToString()));
}
Edit 2: As per Muhammad's observation the first example doesn't work for this. I've used it for other controls, and I didn't see that for the current case it's not correct. Given this I would fill the control from code behind.