What is the best method to test the existence of an attribute on an XML object in ActionScript 3 ?
http://martijnvanbeek.net/weblog/40/testing_the_existance_of_an_attribute_in_xml_with_as3.html is suggesting to test using
if ( node.#test != node.#nonexistingattribute )
and I saw comments suggesting to use:
if ( node.hasOwnProperty('#test')) { // attribute qtest exists }
But in both case, tests are case sensitive.
From the XML Specs : "XML processors should match character encoding names in a case-insensitive way" so I presume attribute name should also be match using a case-insensitive comparison.
Thank you
Please re-read your quote from the XML specs carefully:
XML processors should match character
encoding names in a case-insensitive
way
This is in chapter 4.3.3 of the specs describing character encoding declarations, and it refers only to the names present in the encoding value of the <?xml> processing instruction, such as "UTF-8" or "utf-8". I see absolutely no reason for this to apply to attribute names and/or element names anywhere else in the document.
In fact, there is no mention of this in section 2.3 of the specs, Common Syntactic Constructs, where names and name tokens are specified. There are a few restrictions on special characters and such, but there is absolutely no restriction on upper and lower case letters.
To make your comparison case-insensitive, you will have to do it in Flash:
for each ( var attr:XML in xml.#*) {
if (attr.name().toString().toLowerCase() == test.toLowerCase()) // attribute present if true
}
or rather:
var found:Boolean = false;
for each ( var attr:XML in xml.#*) {
if (attr.name().toString().toLowerCase() == test.toLowerCase()) {
found = true;
break;
}
}
if (found) // attribute present
else // attribute not present
How about using XML's contains() method or XMLList's length() method ?
e.g.
var xml:XML = <root><child id="0" /><child /></root>;
trace(xml.children().#id.length());//test if any children have the id attribute
trace(xml.child[1].#id.length());//test if the second node has the id attribute
trace(xml.contains(<nephew />));//test for inexistend node using contains()
trace(xml.children().nephew.length());//test for inexistend node using legth()
Related
I try to use map directive.
I have 2 vars and if first var exist set it to new var, or if only second var exist, set it to new var.
My config:
map "$arg_arg1:$cookie_1" $new_var {
"~^.*:" $arg_arg1;
"~:.*$" $cookie_1;
default "new";
}
Work only in first situation.
The sequence .* also matches zero characters, so your first regex matches any string containing a :, including those that begin with a :.
Use ^.+: to guarantee at least one character before the : or just .: (as the anchor is not really necessary).
If the cookie value may contain a :, you may want to use ^[^:]+: instead.
My working config:
map "$cookie_1:$arg_arg1" $new_var {
default "new";
"~:.*$" $arg_arg1;
"~*^.*:$" $cookie_1;
}
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'm trying to use a parameter inside of a JSON string, and would like to use an inner parameter to replace an GUID. I've changed the default parameter start and end characters since curly braces are used in JSON.
I've tried to do something like this, where the json param contains my json which is similar to this below.
{"DashboardGUID":"<Dash_GUID>"}
request_json = lr_eval_string("<json>");
lr_save_string(request_json, "request_json_param");
I'm expecting the lr_eval_string to replace the with the GUID that's in this parameter, what's the best why of replacing this ID in my JSON String?
Not sure what you are asking but I will put this here in case someone comes here in the future:
main.c
Action()
{
lr_eval_json("Buffer/File=my_json.json", "JsonObject=MJO",LAST);
lr_json_stringify("JsonObject=MJO","Format=compact", "OutputParam=newJsonBody",LAST);
lr_save_string(lr_eval_string(lr_eval_string("{newJsonBody}")),"tmp");
web_reg_find("Text={mydate}",LAST);
web_rest("POST",
"URL=http://myServer.microfocus.com/url",
"Method=POST",
"EncType=raw",
"Body={tmp}",
HEADERS,
"Name=Content-Type", "Value=application/json", ENDHEADER,
LAST);
return 0;
}
my_json.json
{
"LastActionId": 0,
"Updated": "{mydate}"
}
Okay so instead of doing what I'm thinking above I ended up creating an array of char's with this {"DashboardGUID":"<Dash_GUID>", someotherdata:"123"} in 10 different positions within the array. I then randomly selected an element from this array and when doing the lr_eval_string the parameter was replaced.
Hopefully this makes sense those looking to do something similar.
I need to isolate the file extension from a path in SQLite. I've read the post here (SQLite: How to select part of string?), which gets 99% there.
However, the solution:
select distinct replace(column_name, rtrim(column_name, replace(column_name, '.', '' ) ), '') from table_name;
fails if a file has no extension (i.e. no '.' in the filename), for which it should return an empty string. Is there any way to trap this please?
Note the filename in this context is the bit after the final '\'- it shouldn't be searching for'.'s in the full path, as it does at moment too.
I think it should be possible to do it using further nested rtrims and replaces.
Thanks. Yes, you can do it like this:
1) create a scalar function called "extension" in QtScript in SQLiteStudio
2) The code is as follows:
if ( arguments[0].substring(arguments[0].lastIndexOf('\u005C')).lastIndexOf('.') == -1 )
{
return ("");
}
else
{
return arguments[0].substring(arguments[0].lastIndexOf('.'));
}
3) Then, in the SQL query editor you can use
select distinct extension(PATH) from DATA
... to itemise the distinct file extensions from the column called PATH in the table called DATA.
Note that the PATH field must contain a backslash ('\') in this implementation - i.e. it must be a full path.
I am trying to access an XMLList item and convert it to am XML object.
I am using this expression:
masonicXML.item.(#style_number == styleNum)
For example if there is a match everything works fine but if there is not a match then I get an error when I try cast it as XML saying that it has to be well formed. So I need to make sure that the expression gets a match before I cast it as XML. I tried setting it to an XMLList variable and checking if it as a text() propertie like this:
var defaultItem:XMLList = DataModel.instance.masonicXML.item.(#style_number == styleNum);
if(defaultItem.text())
{
DataModel.instance.selectedItem = XML(defaultItem);
}
But it still give me an error if theres no match. It works fine if there is a match.
THANKS!
In my experience, the simplest way to check for results is to grab the 0th element of the list and see if it's null.
Here is your code sample with a few tweaks. Notice that I've changed the type of defaultItem from XMLList to XML, and I'm assigning it to the 0th element of the list.
var defaultItem:XML =
DataModel.instance.masonicXML.item.(#style_number == styleNum)[0];
if( defaultItem != null )
{
DataModel.instance.selectedItem = defaultItem;
}
OK I got it to work with this:
if(String(defaultItem.#style_number).length)
Matt's null check is a good solution. (Unless there is the possibility of having null items within an XMLList.. probably not, but I haven't verified this.)
You can also check for the length of the XMLList without casting it to a String:
if (defaultItem.#style_number.length() > 0)
The difference to String and Array is that with an XMLList, length() is a method instead of a property.