I would like to have one field appear conditionally based on the value of another. How should I go about achieving this in dexterity?
E.g. One field is a boolean: Is the resource for sale?
If this is set as "yes" I'd like the next field to show up, being an integer- the price of the resource.
If I had to guess, I'd start hacking a javascript solution but I'm assuming there is a technique for doing it in an organised manner, but I can't find anything.
I should also mention that I am doing this to simplify the process of searching through this content later (using eea.facetednav) in which I don't know how to have a boolean search interface return results based on if the integer is > 0.
Related
I am still learning, and looking for help on how to display a label based on one data-sources field value, being within another data-sources field value list.
I have one calculated table, displaying rows of documents within a folder, and wish to use a field representing the document number in that data-source, so that if it's ANYWHERE within another tables field it displays my label.
I've been trying to use projection as I think this is how to achieve it.
I can get it working based on both the current #datasouce.item.fieldnames but need it to base the calculation on all possible numbers in that tables field (Image below should make it easier to understand).
I expect that it has something to do with projections, but can't find anything within the learning templates or anywhere else to resolve the issue.
I think the following should work for you. For the 'Reserved' label have the following binding for the text property:
(#datasources.project_quotes.items..quotenumber).indexOf(#widget.datasource.item.Qnumber) !== -1 ? 'Reserved' : ''
I would suggest alternatively just to include a field in your calculated datasource and making the determination in your server script.
What I wanted is to display an alert when I move to the next row if the record that I inserted is already one of the records in the multi record block.
and in what trigger must I put it?
There are several options you can use.
One is to POST values entered (in WHEN-NEW-RECORD-INSTANCE) trigger. It will, well, post everything you entered so far. Then, you can write a WHEN-VALIDATE-ITEM trigger which SELECTs from that table and checks whether such a value already exists. Alternatively, if there's the UNIQUE CONSTRAINT on that (those) column(s), database will do its job itself, i.e. raise an exception.
Another option is to literally loop through all rows in a block and compare the first row's value with all the others, then the second row's values with all of them, etc.
Or, you can use a Record Group (usually used for Lists of Values). Basically, you'd check whether value you entered exists in a record group. More info, along with a FMB file, on Craig's blog.
Or, you can use calculated items, as described enter link description here (FMB attached as well).
As you can see, quite a few ways to do that; explore each of them and pick the one you find the most useful / attractive / easy to implement.
I would like to define a field, where there is a list of allowed values as well as give user the option to type it in. For example, I list a bunch of previous jobs that the applicant can have, plus have them pick other and fill it in as well.
Is it possible to do this with one field or do I need two fields where the user has to type it in? Is there a doc. or sample or tutorial I can look up? Thanks.
Here is a super simple Tags sample:
https://drive.google.com/open?id=0BxtQI4fTAVQqcUx4OUJfQ1JYV2c
To cover your exact use case you just need to:
Add logic to check if record already exists
1.1 If record doesn't exist, then create one
Create relation between records
If you don't care about duplicates in your database, then you can skip step 1 and always do 1.1 and 2.
I have a lot of objects with unique IDs. Every object can have several labels associated to it, like this:
123: ['a', 'hello']
456: ['dsajdaskldjs']
789: (no labels associated yet)
I'm not planning to store all objects in DynamoDB, only these sets of labels. So it would make sense to add labels like that:
find a record with (id = needed_id)
if there is one, and it has a set named label_set, add a label to this set
if there is no record with such id, or the existing record doesn't have an attribute named label_set, create a record and an attribute, and initialize the attribute with a set consisting of the label
if I used sets of numbers, I could use just ADD operation of UPDATE command. This command does exactly what I described. However, this does not work with sets of strings:
If no item matches the specified primary key:
ADD— Creates an item with supplied primary key and number (or set of numbers) for the attribute value. Not valid for a string type.
so I have to use a PUT operation with Expected set to {"label_set":{"Exists":false}}, followed (in case it fails) by an ADD operation. These are two operations, and it kinda sucks (since you pay per operation, the costs of this will be 2 times more than they could be).
This limitations seems really weird to me. Why are something what works with numbers sets would not work with string sets? Maybe I'm doing something wrong.
Using many records like (123, 'a'), (123, 'hello') instead of one record per object with a set is not a solutions: I want to get all the values from the set at once, without any scans.
I use string sets from the Java SDK the way you describe all the time and it works for me. Perhaps it has changed? I basically follow the pattern in this doc:
http://docs.amazonwebservices.com/amazondynamodb/latest/developerguide/API_UpdateItem.html
ADD— Only use the add action for numbers or if the target attribute is
a set (including string sets). ADD does not work if the target
attribute is a single string value or a scalar binary value. The
specified value is added to a numeric value (incrementing or
decrementing the existing numeric value) or added as an additional
value in a string set. If a set of values is specified, the values are
added to the existing set. For example if the original set is [1,2]
and supplied value is [3], then after the add operation the set is
[1,2,3], not [4,5]. An error occurs if an Add action is specified for
a set attribute and the attribute type specified does not match the
existing set type.
If you use ADD for an attribute that does not exist, the attribute and
its values are added to the item.
When your set is empty, it means the attribute isn't present. You can still ADD to it. In fact, a pattern that I've found useful is to simply ADD without even checking for the item. If it doesn't exist, it will create a new item using the specified key and create the attribute set with the value(s) I am adding. If the item exists but the attribute doesn't, it creates the attribute set and adds the value(s). If they both exist, it just adds the value(s).
The only piece that caught me up at first was that the value I had to add was a SS (String set) even if it was only one string value. From DynamoDB's perspective, you are always merging sets, even if the existing set is an empty set (missing) or the new set only contains one value.
IMO, from the way you've described your intent, you would be better off not specifying an existing condition at all. You are having to do two steps because you are enforcing two different situations but you are trying to perform the same action in both. So might as well just blindly add the label and let DynamoDB handle the rest.
Maybe you could: (pseudo code)
try:
add_with_update_item(hash_key=42, "label")
except:
element = new Element(hash_key=42, labels=["label"])
element.save()
With this graceful recovery approach, you need 1 call in the general case, 2 otherwise.
You are unable to use sets to do what you want because Dynamo Db doesn't support empty sets. I would suggest just using a string with a custom schema and building the set from that yourself.
To avoid two operations, you can add a "ConditionExpression" to your item.
For example, add this field/value to your item:
"ConditionExpression": "attribute_not_exists(RecordID) and attribute_not_exists(label_set)"
Source documentation.
Edit: I found a really good guide about how to use the conditional statements
In a specific table I have a SortOrder integer field that tells my page in which order to display the data. There are sets of data in the this field (based on a CategoryID field), and each set will have its own ordering. Users can add/remove/update records in this table.
My question is what is the best way to manage this SortOrder field? I would like to "reseed" it everytime a record is deleted or updated. Is this something I should be using a trigger for? Or should my code handle it and manage the reseeding?
What I used to do is use only odd numbers in the SortOrder field so upon changing the order, I would add or subtract 3 from the current value of the modified item and then do a reseed (order the items again using odd number indexes). Also I used to reseed after every insert or delete.
All you really have to worry about is swapping any two fields. All new entries go to the end and i'm sure you've got a mechanism by which the user can change the order. The order change, move up or down, really is a swap with a neighboring field. All you really care about is that all the fields are sorted properly. Don't let a mathematical sense of aesthetic drive you into creating something overly complex. (You'll end up with holes in your sequence after deletes are made but that's OK. It's an internal sequence marker used for ORDER BY. the numbers don't need to be made contiguous.)