Using Dynamic References with Standard Objects

1public class DynamicAccountFieldsLister {
2
3    public DynamicAccountFieldsLister(ApexPages.StandardController controller) { 
4        controller.addFields(editableFields);
5    }
6
7    public List<String> editableFields {
8        get {
9            if (editableFields == null) {
10                editableFields = new List<String>();
11                editableFields.add('Industry');
12                editableFields.add('AnnualRevenue');
13                editableFields.add('BillingCity');
14            }
15            return editableFields ;
16        }
17        private set;
18    }
19}

1public DynamicAccountFieldsLister(ApexPages.StandardController controller) { 
2        controller.addFields(editableFields);
3    }

1public class DynamicCaseLoader {
2
3    public final Case caseDetails { get; private set; }
4
5    // SOQL query loads the case, with Case fields and related Contact fields
6    public DynamicCaseLoader(ApexPages.StandardController controller) {
7        String qid = ApexPages.currentPage().getParameters().get('id');
8        String theQuery = 'SELECT Id, ' + joinList(caseFieldList, ', ') + 
9                          ' FROM Case WHERE Id = :qid';
10        this.caseDetails = Database.query(theQuery);
11    }
12
13    // A list of fields to show on the Visualforce page
14    public List<String> caseFieldList { 
15        get {
16            if (caseFieldList == null) {
17                caseFieldList = new List<String>();
18                caseFieldList.add('CaseNumber');
19                caseFieldList.add('Origin');
20                caseFieldList.add('Status');
21                caseFieldList.add('Contact.Name');  // related field
22                caseFieldList.add('Contact.Email'); // related field
23                caseFieldList.add('Contact.Phone'); // related field
24            }
25            return caseFieldList;
26        }
27        private set;
28    }
29    
30    // Join an Apex list of fields into a SELECT fields list string
31    private static String joinList(List<String> theList, String separator) {
32
33        if (theList == null) {
34            return null;
35        }
36        if (separator == null) {
37            separator = '';
38        }
39
40        String joined = '';
41        Boolean firstItem = true;
42        for (String item : theList) {
43            if(null != item) {
44                if(firstItem){
45                    firstItem = false;
46                }
47                else {
48                    joined += separator;               
49                }
50                joined += item;
51            }
52        }
53        return joined;
54    }
55}

1public class DynamicCustomizableListHandler {
2
3    // Resources we need to hold on to across requests
4    private ApexPages.StandardSetController controller;
5    private PageReference savePage;
6
7    // This is the state for the list "app"
8    private Set<String> unSelectedNames = new Set<String>();
9    private Set<String> selectedNames = new Set<String>();
10    private Set<String> inaccessibleNames = new Set<String>();
11
12    public DynamicCustomizableListHandler(ApexPages.StandardSetController controller) {
13        this.controller = controller;
14        loadFieldsWithVisibility();
15    }
16
17    // Initial load of the fields lists
18    private void loadFieldsWithVisibility() {
19        Map<String, Schema.SobjectField> fields = 
20            Schema.SobjectType.Account.fields.getMap();
21        for (String s : fields.keySet()) {
22            if (s != 'Name') {  // name is always displayed 
23                unSelectedNames.add(s);
24            }
25            if (!fields.get(s).getDescribe().isAccessible()) {
26                inaccessibleNames.add(s);
27            }
28        }
29    }
30
31    // The fields to show in the list
32    // This is what we generate the dynamic references from
33    public List<String> getDisplayFields() { 
34        List<String> displayFields = new List<String>(selectedNames);
35        displayFields.sort();
36        return displayFields;
37    }
38    
39    // Nav: go to customize screen
40    public PageReference customize() {
41        savePage = ApexPages.currentPage();
42        return Page.CustomizeDynamicList;
43    }
44
45    // Nav: return to list view
46    public PageReference show() {
47        // This forces a re-query with the new fields list
48        controller.reset();
49        controller.addFields(getDisplayFields());
50        return savePage; 
51    }
52
53    // Create the select options for the two select lists on the page
54    public List<SelectOption> getSelectedOptions() { 
55        return selectOptionsFromSet(selectedNames);
56    }
57    public List<SelectOption> getUnSelectedOptions() { 
58        return selectOptionsFromSet(unSelectedNames);
59    }
60    
61    private List<SelectOption> selectOptionsFromSet(Set<String> opts) {
62        List<String> optionsList = new List<String>(opts);
63        optionsList.sort();
64        List<SelectOption> options = new List<SelectOption>();
65        for (String s : optionsList) {
66            options.add(new 
67                SelectOption(s, decorateName(s), inaccessibleNames.contains(s)));
68        }
69        return options;
70    }
71
72    private String decorateName(String s) {
73        return inaccessibleNames.contains(s) ? '*' + s : s;
74    }
75
76    // These properties receive the customization form postback data
77    // Each time the [<<] or [>>] button is clicked, these get the contents
78    // of the respective selection lists from the form
79    public transient List<String> selected   { get; set; }
80    public transient List<String> unselected { get; set; }
81
82    // Handle the actual button clicks. Page gets updated via a
83    // rerender on the form
84    public void doAdd() {
85        moveFields(selected, selectedNames, unSelectedNames);
86    }
87    public void doRemove() {
88        moveFields(unselected, unSelectedNames, selectedNames);
89    }
90    
91    private void moveFields(List<String> items, 
92            Set<String> moveTo, Set<String> removeFrom) {
93        for (String s: items) {
94            if( ! inaccessibleNames.contains(s)) {
95                moveTo.add(s);
96                removeFrom.remove(s);
97            }
98        }
99    }
100}