In coredata, i have a transient property to use has sections. The transient property code is here:
- (NSString *) firstLetter_transient {
[self willAccessValueForKey:#"firstLetter_transient"];
NSString *initial = [[[self memberName] substringToIndex:1] uppercaseString];
[self didAccessValueForKey:#"firstLetter_transient"];
return initial;
}
When I apply this, in Portuguese language, I get, for example "Á" has the first letter.
Question Nr 1: how can I put "Á" in the "A" section? I have an error with this:
"The operation couldn’t be completed. (Cocoa error 134060.)"
Question Nr 2: when it comes to numbers, how can I affect the numbers to section named "#"? Now, the number 1 creates a section "1", and so on.
Thanks all,
RL
You should use UILocalizedIndexedCollation for doing sorting and categorizing entries into sections. The code for implementing this is in the question NSFetchedResultsController v.s. UILocalizedIndexedCollation
The UILocalizedIndexedCollation was built to be able to on a per-language basis categorize words based on the current language settings. Á and à will be put in section A.
Related
I have a very bland messagebox asking my users a simple question (not yes or no). For quick development I used a simple System.Windows.Forms.MessageBox and worded the question ("If you want to choose 'A' click 'Yes' if you want to choose 'B' click 'No'"). Now I'm going back and improving the look and feel of my wpf application and I'm stuck trying to convert this MessageBox into something that looks good.
My preliminary search told me to use Xceed.Wpf.Toolkit.MessageBox to be able to create custom message box but I'm getting an exception when I'm trying to use it.
Old Code
DialogResult dialogResultForDataDisplay = System.Windows.Forms.MessageBox.Show("Yes: Display by properties \n \t Each row will contain data for a specific asset class in a specific submarket during a specific quarter. \n \n No: Display by quarters \n \t Each row will will show the change over time for a specific property of an asset class in a specific submarket.", "Data Grouping Format", MessageBoxButtons.YesNo);
New Code
Style style = new Style();
style.Setters.Add(new Setter(Xceed.Wpf.Toolkit.MessageBox.YesButtonContentProperty, "By Property"));
style.Setters.Add(new Setter(Xceed.Wpf.Toolkit.MessageBox.NoButtonContentProperty, "By Quarter"));
MessageBoxResult result = Xceed.Wpf.Toolkit.MessageBox.Show("How do you want your information displayed?", "My caption", MessageBoxButton.YesNo, MessageBoxImage.Warning, MessageBoxResult.Yes, style);
Console.WriteLine(result);
The new code is generating this exception: System.InvalidOperationException: 'The calling thread must be STA, because many UI components require this.'
How would you go about handling this exception?
One solution I found now is rapping it in an invoke method. If someone has a better solution please post.
MessageBoxResult result = MessageBoxResult.None;
System.Windows.Application.Current.Dispatcher.Invoke((Action)delegate
{
Style style = new Style();
style.Setters.Add(new Setter(Xceed.Wpf.Toolkit.MessageBox.YesButtonContentProperty, "Yes, FTW!"));
style.Setters.Add(new Setter(Xceed.Wpf.Toolkit.MessageBox.NoButtonContentProperty, "Omg, no"));
result = Xceed.Wpf.Toolkit.MessageBox.Show("How do you want your information displayed?", "My caption", MessageBoxButton.YesNo, MessageBoxImage.Warning, MessageBoxResult.Yes, style);
}
Console.WriteLine(result);
Consider a Core Data model with two Entities: TermDictionary and Term. The TermDictionary has a "name" property, and a one-to-many relationship called "terms" which points to a set of Term objects, each of which consists of two properties: "name" and "score".
I've got an NSFetchRequest which I'm using as a data source for a UITableView which displays all of the TermDictionaries in the database. The idea is that the table will, for each cell, display the name of the dictionary, along with a count of the number of terms in that dictionary.
In the following code snippet, item contains an NSFetchRequestResult for the "TermDictionary" entity:
let thisDict = item as! TermDictionary
cell.textLabel?.text = thisDict.name
cell.detailTextLabel?.text = "\(thisDict.terms?.count ?? 0) terms"
...The table cells are correctly displaying the names of the Term Dictionaries, however it looks like thisDict.terms is always coming up nil, so the number-of-terms label always shows zero.
Do I need do do something special with item rather than just casting it to my TermDictionary managed object subclass?
You do not need to do anything special. If thisDict.terms prints as nil, it really is nil. Check your data store.
In my app I have a Core Data entity called Status with two attributes messageID as Integer32 and messageText as String.
I have a string stored in an SQL database which the app downloads on startup. The string from the database is broken down into two parts ID and text. An example message could be 011-Hello and the each part is stored in an array called messageParts. The first item in the array is the ID:
NSInteger newMessageID = [messageParts[0] integerValue];
I want to compare this ID with the one stored in Core Data such as:
if (messageID == newMessageID)
I get the newMessageID fine and I have a number to work with but I am totally confused as to how to handle the data type coming from Core Data. I can see that there is a number in the database using SQLlitebrowser and I have tried:
NSInteger *savedMessageID = [[self.status objectAtIndex:0] messageID];
and
NSInteger savedMessageID = [[self.status objectAtIndex:0] messageID];
But neither return the stored value. I think that this is a pointer issue but I am going around in circles here.
If you generate the NSManagedObject subclass from your xcdatamodeld (Xcode menu Editor > Create NSManagedObject Subclass…), you will find that the integer32 field is generated as an NSNumber...
This is maybe where you should take a look ?
How do I sort my fetched results by a value that is returned by a method in a category of the entity I'm fetching?
In my category, I sum up several values from the entity's to-many relationship, then divide by the number of objects in the relationship, effectively creating an average that I return in my category method as a float value.
Here is my code:
In the Category.h
- (float)smallPenaltyAvg;
In the Category.m
- (float)smallPenaltyAvg{
float smallPenaltyAvg = 0;
for (Match *mtch in self.matches) {
smallPenaltyAvg += [mtch.penaltySmall floatValue];
}
if ([self.matches count] > 0) {
smallPenaltyAvg = (float)smallPenaltyAvg/(float)[self.matches count];
}
return smallPenaltyAvg;
}
And when I call it in the Core Data Table View Controller class that I created...
NSFetchRequest *poolRequest = [[NSFetchRequest alloc] initWithEntityName:#"Team"];
poolRequest.predicate = [NSPredicate predicateWithFormat:#"regionalIn.name = %#", _regionalToDisplay];
poolRequest.sortDescriptors = #[[NSSortDescriptor sortDescriptorWithKey:#"smallPenaltyAvg" ascending:YES]];
And I have the Category.h file imported on every file previously mentioned outside of the Category.h file itself.
It gives me the error of:
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath smallPenaltyAvg not found in entity <NSSQLEntity Team id=5>
Am I not allowed to do this?
If I am, what am I doing wrong?
I do not think this has anything to do with the kind of persistent store.
The trick is to create an appropriate attribute in the managed object model, and mark it as Transient. Then override the getter of this attribute to do your calculations.
Now your fetch request should work as expected (although there are some caveats with fetched results controllers).
As for the SQLite problem, when you add the SQLite store with
- (NSPersistentStore *)addPersistentStoreWithType:(NSString *)storeType
configuration:(NSString *)configuration
URL:(NSURL *)storeURL
options:(NSDictionary *)options
error:(NSError **)error
just pass NSSQLiteStoreType as the storeType. The other options are binary and in-memory, so in this sense this is indeed the "default".
This is not possible when using a backing SQLite store.
My suggestion is you persist the average property, and maintain it yourself by overriding the Match setCategory: property and making the calculation there for every match added.
What I did to solve my problem was create a new attribute for every average or sum that I needed in the Team object from all of its Match objects' attributes and then created a method in the TeamCategory file that populated those averages and that method was called every time a Match object was inserted into the Team object. It took a while to do, but it works now. If there is a better solution, I'm still open for suggestions.
We are working on integrating Solr 3.6 to an eCommerce site. We have indexed data & search is performing really good.
We have some difficulties figuring how to use Predictive Search / Auto Complete Search Suggestion. Also interested to learn the best practices for implementing this feature.
Our goal is to offer predictive search similar to http://www.amazon.com/, but don't know how to implement it with Solr. More specifically I want to understand how to build those terms from Solr, or is it managed by something else external to solr? How the dictionary should be built for offering these kind of suggestions? Moreover, for some field, search should offer to search in category. Try typing "xper" into Amazon search box, and you will note that apart from xperia, xperia s, xperia p, it also list xperia s in Cell phones & accessories, which is a category.
Using a custom dictionary this would be difficult to manage. Or may be we don't know how to do it correctly. Looking to you to guide us on how best utilize solr to achieve this kind of suggestive search.
I would suggest you a couple of blogpost:
This one which shows you a really nice complete solution which works well but requires some additional work to be made, and uses a specific lucene index (solr core) for that specific purpose
I used the Highlight approach because the facet.prefix one is too heavy for big index, and the other ones had few or unclear documentation (i'm a stupid programmer)
So let's suppose the user has just typed "aaa bbb ccc"
Our autocomplete function (java/javascript) will call solr using the following params
q="aaa bbb"~100 ...base query, all the typed words except the last
fq=ccc* ...suggest word filter using last typed word
hl=true
hl.q=ccc* ...highlight word will be the one to suggest
fl=NONE ...return empty docs in result tag
hl.pre=### ...escape chars to locate highlight word in the response
hl.post=### ...see above
you can also control the number of suggestion with 'rows' and 'hl.fragsize' parameters
the highlight words in each document will be the right candidates for the suggestion with "aaa bbb" string
more suggestion words are the ones before/after the highlight words and, of course, you can implement more filters to extract valid words, avoid duplicates, limit suggestions
if interested i can send you some examples...
EDITED: Some further details about the approach
The portion of example i give supposes the 'autocomplete' mechanism given by jquery: we invoke a jsp (or a servlet) inside a web application passing as request param 'q' the words just typed by user.
This is the code of the jsp
ByteArrayInputStream is=null; // Used to manage Solr response
try{
StringBuffer queryUrl=new StringBuffer('putHereTheUrlOfSolrServer');
queryUrl.append("/select?wt=xml");
String typedWords=request.getParameter("q");
String base="";
if(typedWords.indexOf(" ")<=0) {
// No space typed by user: the 'easy case'
queryUrl.append("&q=text:");
queryUrl.append(URLEncoder.encode(typedWords+"*", "UTF-8"));
queryUrl.append("&hl.q=text:"+URLEncoder.encode(typedWords+"*", "UTF-8"));
} else {
// Space chars present
// we split the search in base phrase and last typed word
base=typedWords.substring(0,typedWords.lastIndexOf(" "));
queryUrl.append("&q=text:");
if(base.indexOf(" ")>0)
queryUrl.append("\""+URLEncoder.encode(base, "UTF-8")+"\"~1000");
else
queryUrl.append(URLEncoder.encode(base, "UTF-8"));
typedWords=typedWords.substring(typedWords.lastIndexOf(" ")+1);
queryUrl.append("&fq=text:"+URLEncoder.encode(typedWords+"*", "UTF-8"));
queryUrl.append("&hl.q=text:"+URLEncoder.encode(typedWords+"*", "UTF-8"));
}
// The additional parameters to control the solr response
queryUrl.append("&rows="+suggestPageSize); // Number of results returned, a parameter to control the number of suggestions
queryUrl.append("&fl=A_FIELD_NAME_THAT_DOES_NOT_EXIST"); // Interested only in highlights section, Solr return a 'light' answer
queryUrl.append("&start=0"); // Use only first page of results
queryUrl.append("&hl=true"); // Enable highlights feature
queryUrl.append("&hl.simple.pre=***"); // Use *** as 'highlight border'
queryUrl.append("&hl.simple.post=***"); // Use *** as 'highlight border'
queryUrl.append("&hl.fragsize="+suggestFragSize); // Another parameter to control the number of suggestions
queryUrl.append("&hl.fl=content,title"); // Look for result only in some fields
queryUrl.append("&facet=false"); // Disable facets
/* Omitted section: use a new URL(queryUrl.toString()) to get the solr response inside a byte array */
is=new ByteArrayInputStream(solrResponseByteArray);
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(is);
XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
XPathExpression expr = xpath.compile("//response/lst[#name=\"highlighting\"]/lst/arr[#name=\"content\"]/str");
NodeList valueList = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);
Vector<String> suggestions=new Vector<String>();
for (int j = 0; j < valueList.getLength(); ++j) {
Element value = (Element) valueList.item(j);
String[] result=value.getTextContent().split("\\*\\*\\*");
for(int k=0;k<result.length;k++){
String suggestedWord=result[k].toLowerCase();
if((k%2)!=0){
//Highlighted words management
if(suggestedWord.length()>=suggestedWord.length() && !suggestions.contains(suggestedWord))
suggestions.add(suggestedWord);
}else{
/* Words before/after highlighted words
we can put these words inside another vector
and use them if not enough suggestions */
}
}
}
/* Finally we build a Json Answer to be managed by our jquery function */
out.print(request.getParameter("json.wrf")+"({ \"suggestions\" : [");
boolean firstSugg=true;
for(String suggestionW:suggestions) {
out.print((firstSugg?" ":" ,"));
out.print("{ \"suggest\" : \"");
if(base.length()>0) {
out.print(base);
out.print(" ");
}
out.print(suggestionW+"\" }");
firstSugg=false;
}
out.print(" ]})");
}catch (Exception x) {
System.err.println("Exception during main process: " + x);
x.printStackTrace();
}finally{
//Gracefully close streams//
try{is.close();}catch(Exception x){;}
}
Hope to be helpfull,
Nik
This might help you out.I am trying to do the same.
http://solr.pl/en/2010/10/18/solr-and-autocomplete-part-1/