001/**
002 *
003 * Copyright 2003-2007 Jive Software.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.xdata;
018
019import java.util.ArrayList;
020import java.util.Iterator;
021import java.util.List;
022import java.util.StringTokenizer;
023
024import org.jivesoftware.smack.packet.Stanza;
025import org.jivesoftware.smackx.xdata.packet.DataForm;
026
027/**
028 * Represents a Form for gathering data. The form could be of the following types:
029 * <ul>
030 *  <li>form &rarr; Indicates a form to fill out.</li>
031 *  <li>submit &rarr; The form is filled out, and this is the data that is being returned from 
032 * the form.</li>
033 *  <li>cancel &rarr; The form was cancelled. Tell the asker that piece of information.</li>
034 *  <li>result &rarr; Data results being returned from a search, or some other query.</li>
035 * </ul>
036 * 
037 * Depending of the form's type different operations are available. For example, it's only possible
038 * to set answers if the form is of type "submit".
039 * 
040 * @see <a href="http://xmpp.org/extensions/xep-0004.html">XEP-0004 Data Forms</a>
041 * 
042 * @author Gaston Dombiak
043 */
044public class Form {
045
046    private DataForm dataForm;
047
048    /**
049     * Returns a new ReportedData if the stanza(/packet) is used for gathering data and includes an 
050     * extension that matches the elementName and namespace "x","jabber:x:data".  
051     * 
052     * @param packet the stanza(/packet) used for gathering data.
053     * @return the data form parsed from the stanza(/packet) or <tt>null</tt> if there was not
054     *      a form in the packet.
055     */
056    public static Form getFormFrom(Stanza packet) {
057        // Check if the packet includes the DataForm extension
058        DataForm dataForm = DataForm.from(packet);
059        if (dataForm != null) {
060            if (dataForm.getReportedData() == null)
061                return new Form(dataForm);
062        }
063        // Otherwise return null
064        return null;
065    }
066
067    /**
068     * Creates a new Form that will wrap an existing DataForm. The wrapped DataForm must be
069     * used for gathering data. 
070     * 
071     * @param dataForm the data form used for gathering data. 
072     */
073    public Form(DataForm dataForm) {
074        this.dataForm = dataForm;
075    }
076
077    /**
078     * Creates a new Form of a given type from scratch.
079     *
080     * @param type the form's type (e.g. form, submit,cancel,result).
081     */
082    public Form(DataForm.Type type) {
083        this.dataForm = new DataForm(type);
084    }
085
086    /**
087     * Adds a new field to complete as part of the form.
088     * 
089     * @param field the field to complete.
090     */
091    public void addField(FormField field) {
092        dataForm.addField(field);
093    }
094
095    /**
096     * Sets a new String value to a given form's field. The field whose variable matches the 
097     * requested variable will be completed with the specified value. If no field could be found 
098     * for the specified variable then an exception will be raised.<p>
099     * 
100     * If the value to set to the field is not a basic type (e.g. String, boolean, int, etc.) you
101     * can use this message where the String value is the String representation of the object. 
102     * 
103     * @param variable the variable name that was completed.
104     * @param value the String value that was answered.
105     * @throws IllegalStateException if the form is not of type "submit".
106     * @throws IllegalArgumentException if the form does not include the specified variable or
107     *      if the answer type does not correspond with the field type..
108     */
109    public void setAnswer(String variable, String value) {
110        FormField field = getField(variable);
111        if (field == null) {
112            throw new IllegalArgumentException("Field not found for the specified variable name.");
113        }
114        switch (field.getType()) {
115        case text_multi:
116        case text_private:
117        case text_single:
118        case jid_single:
119        case hidden:
120            break;
121        default:
122            throw new IllegalArgumentException("This field is not of type String.");
123        }
124        setAnswer(field, value);
125    }
126
127    /**
128     * Sets a new int value to a given form's field. The field whose variable matches the 
129     * requested variable will be completed with the specified value. If no field could be found 
130     * for the specified variable then an exception will be raised.
131     * 
132     * @param variable the variable name that was completed.
133     * @param value the int value that was answered.
134     * @throws IllegalStateException if the form is not of type "submit".
135     * @throws IllegalArgumentException if the form does not include the specified variable or
136     *      if the answer type does not correspond with the field type.
137     */
138    public void setAnswer(String variable, int value) {
139        FormField field = getField(variable);
140        if (field == null) {
141            throw new IllegalArgumentException("Field not found for the specified variable name.");
142        }
143        validateThatFieldIsText(field);
144        setAnswer(field, value);
145    }
146
147    /**
148     * Sets a new long value to a given form's field. The field whose variable matches the 
149     * requested variable will be completed with the specified value. If no field could be found 
150     * for the specified variable then an exception will be raised.
151     * 
152     * @param variable the variable name that was completed.
153     * @param value the long value that was answered.
154     * @throws IllegalStateException if the form is not of type "submit".
155     * @throws IllegalArgumentException if the form does not include the specified variable or
156     *      if the answer type does not correspond with the field type.
157     */
158    public void setAnswer(String variable, long value) {
159        FormField field = getField(variable);
160        if (field == null) {
161            throw new IllegalArgumentException("Field not found for the specified variable name.");
162        }
163        validateThatFieldIsText(field);
164        setAnswer(field, value);
165    }
166
167    /**
168     * Sets a new float value to a given form's field. The field whose variable matches the 
169     * requested variable will be completed with the specified value. If no field could be found 
170     * for the specified variable then an exception will be raised.
171     * 
172     * @param variable the variable name that was completed.
173     * @param value the float value that was answered.
174     * @throws IllegalStateException if the form is not of type "submit".
175     * @throws IllegalArgumentException if the form does not include the specified variable or
176     *      if the answer type does not correspond with the field type.
177     */
178    public void setAnswer(String variable, float value) {
179        FormField field = getField(variable);
180        if (field == null) {
181            throw new IllegalArgumentException("Field not found for the specified variable name.");
182        }
183        validateThatFieldIsText(field);
184        setAnswer(field, value);
185    }
186
187    /**
188     * Sets a new double value to a given form's field. The field whose variable matches the 
189     * requested variable will be completed with the specified value. If no field could be found 
190     * for the specified variable then an exception will be raised.
191     * 
192     * @param variable the variable name that was completed.
193     * @param value the double value that was answered.
194     * @throws IllegalStateException if the form is not of type "submit".
195     * @throws IllegalArgumentException if the form does not include the specified variable or
196     *      if the answer type does not correspond with the field type.
197     */
198    public void setAnswer(String variable, double value) {
199        FormField field = getField(variable);
200        if (field == null) {
201            throw new IllegalArgumentException("Field not found for the specified variable name.");
202        }
203        validateThatFieldIsText(field);
204        setAnswer(field, value);
205    }
206
207    private static void validateThatFieldIsText(FormField field) {
208        switch(field.getType()) {
209        case text_multi:
210        case text_private:
211        case text_single:
212            break;
213        default:
214            throw new IllegalArgumentException("This field is not of type text (multi, private or single).");
215        }
216    }
217
218    /**
219     * Sets a new boolean value to a given form's field. The field whose variable matches the 
220     * requested variable will be completed with the specified value. If no field could be found 
221     * for the specified variable then an exception will be raised.
222     * 
223     * @param variable the variable name that was completed.
224     * @param value the boolean value that was answered.
225     * @throws IllegalStateException if the form is not of type "submit".
226     * @throws IllegalArgumentException if the form does not include the specified variable or
227     *      if the answer type does not correspond with the field type.
228     */
229    public void setAnswer(String variable, boolean value) {
230        FormField field = getField(variable);
231        if (field == null) {
232            throw new IllegalArgumentException("Field not found for the specified variable name.");
233        }
234        if (field.getType() != FormField.Type.bool) {
235            throw new IllegalArgumentException("This field is not of type boolean.");
236        }
237        setAnswer(field, (value ? "1" : "0"));
238    }
239
240    /**
241     * Sets a new Object value to a given form's field. In fact, the object representation 
242     * (i.e. #toString) will be the actual value of the field.<p>
243     * 
244     * If the value to set to the field is not a basic type (e.g. String, boolean, int, etc.) you
245     * will need to use {@link #setAnswer(String, String)} where the String value is the 
246     * String representation of the object.<p> 
247     * 
248     * Before setting the new value to the field we will check if the form is of type submit. If 
249     * the form isn't of type submit means that it's not possible to complete the form and an   
250     * exception will be thrown.
251     * 
252     * @param field the form field that was completed.
253     * @param value the Object value that was answered. The object representation will be the 
254     * actual value.
255     * @throws IllegalStateException if the form is not of type "submit".
256     */
257    private void setAnswer(FormField field, Object value) {
258        if (!isSubmitType()) {
259            throw new IllegalStateException("Cannot set an answer if the form is not of type " +
260            "\"submit\"");
261        }
262        field.resetValues();
263        field.addValue(value.toString());
264    }
265
266    /**
267     * Sets a new values to a given form's field. The field whose variable matches the requested 
268     * variable will be completed with the specified values. If no field could be found for 
269     * the specified variable then an exception will be raised.<p>
270     * 
271     * The Objects contained in the List could be of any type. The String representation of them
272     * (i.e. #toString) will be actually used when sending the answer to the server.
273     * 
274     * @param variable the variable that was completed.
275     * @param values the values that were answered.
276     * @throws IllegalStateException if the form is not of type "submit".
277     * @throws IllegalArgumentException if the form does not include the specified variable.
278     */
279    public void setAnswer(String variable, List<String> values) {
280        if (!isSubmitType()) {
281            throw new IllegalStateException("Cannot set an answer if the form is not of type " +
282            "\"submit\"");
283        }
284        FormField field = getField(variable);
285        if (field != null) {
286            // Check that the field can accept a collection of values
287            switch (field.getType()) {
288            case jid_multi:
289            case list_multi:
290            case list_single:
291            case text_multi:
292            case hidden:
293                break;
294            default:
295                throw new IllegalArgumentException("This field only accept list of values.");
296            }
297            // Clear the old values 
298            field.resetValues();
299            // Set the new values. The string representation of each value will be actually used.
300            field.addValues(values);
301        }
302        else {
303            throw new IllegalArgumentException("Couldn't find a field for the specified variable.");
304        }
305    }
306
307    /**
308     * Sets the default value as the value of a given form's field. The field whose variable matches
309     * the requested variable will be completed with its default value. If no field could be found
310     * for the specified variable then an exception will be raised.
311     *
312     * @param variable the variable to complete with its default value.
313     * @throws IllegalStateException if the form is not of type "submit".
314     * @throws IllegalArgumentException if the form does not include the specified variable.
315     */
316    public void setDefaultAnswer(String variable) {
317        if (!isSubmitType()) {
318            throw new IllegalStateException("Cannot set an answer if the form is not of type " +
319            "\"submit\"");
320        }
321        FormField field = getField(variable);
322        if (field != null) {
323            // Clear the old values
324            field.resetValues();
325            // Set the default value
326            for (String value : field.getValues()) {
327                field.addValue(value);
328            }
329        }
330        else {
331            throw new IllegalArgumentException("Couldn't find a field for the specified variable.");
332        }
333    }
334
335    /**
336     * Returns a List of the fields that are part of the form.
337     *
338     * @return a List of the fields that are part of the form.
339     */
340    public List<FormField> getFields() {
341        return dataForm.getFields();
342    }
343
344    /**
345     * Returns the field of the form whose variable matches the specified variable.
346     * The fields of type FIXED will never be returned since they do not specify a 
347     * variable. 
348     * 
349     * @param variable the variable to look for in the form fields. 
350     * @return the field of the form whose variable matches the specified variable.
351     */
352    public FormField getField(String variable) {
353        return dataForm.getField(variable);
354    }
355
356    /**
357     * Check if a field with the given variable exists.
358     *
359     * @param variable the variable to check for.
360     * @return true if a field with the variable exists, false otherwise.
361     * @since 4.2
362     */
363    public boolean hasField(String variable) {
364        return dataForm.hasField(variable);
365    }
366
367    /**
368     * Returns the instructions that explain how to fill out the form and what the form is about.
369     * 
370     * @return instructions that explain how to fill out the form.
371     */
372    public String getInstructions() {
373        StringBuilder sb = new StringBuilder();
374        // Join the list of instructions together separated by newlines
375        for (Iterator<String> it = dataForm.getInstructions().iterator(); it.hasNext();) {
376            sb.append(it.next());
377            // If this is not the last instruction then append a newline
378            if (it.hasNext()) {
379                sb.append('\n');
380            }
381        }
382        return sb.toString();
383    }
384
385
386    /**
387     * Returns the description of the data. It is similar to the title on a web page or an X 
388     * window.  You can put a title on either a form to fill out, or a set of data results.
389     * 
390     * @return description of the data.
391     */
392    public String getTitle() {
393        return dataForm.getTitle();
394    }
395
396
397    /**
398     * Returns the meaning of the data within the context. The data could be part of a form
399     * to fill out, a form submission or data results.
400     * 
401     * @return the form's type.
402     */
403    public DataForm.Type getType() {
404        return dataForm.getType(); 
405    }
406
407
408    /**
409     * Sets instructions that explain how to fill out the form and what the form is about.
410     * 
411     * @param instructions instructions that explain how to fill out the form.
412     */
413    public void setInstructions(String instructions) {
414        // Split the instructions into multiple instructions for each existent newline
415        ArrayList<String> instructionsList = new ArrayList<String>();
416        StringTokenizer st = new StringTokenizer(instructions, "\n");
417        while (st.hasMoreTokens()) {
418            instructionsList.add(st.nextToken());
419        }
420        // Set the new list of instructions
421        dataForm.setInstructions(instructionsList);
422
423    }
424
425
426    /**
427     * Sets the description of the data. It is similar to the title on a web page or an X window.
428     * You can put a title on either a form to fill out, or a set of data results.
429     * 
430     * @param title description of the data.
431     */
432    public void setTitle(String title) {
433        dataForm.setTitle(title);
434    }
435
436    /**
437     * Returns a DataForm that serves to send this Form to the server. If the form is of type 
438     * submit, it may contain fields with no value. These fields will be removed since they only 
439     * exist to assist the user while editing/completing the form in a UI. 
440     * 
441     * @return the wrapped DataForm.
442     */
443    public DataForm getDataFormToSend() {
444        if (isSubmitType()) {
445            // Create a new DataForm that contains only the answered fields 
446            DataForm dataFormToSend = new DataForm(getType());
447            for(FormField field : getFields()) {
448                if (!field.getValues().isEmpty()) {
449                    dataFormToSend.addField(field);
450                }
451            }
452            return dataFormToSend;
453        }
454        return dataForm;
455    }
456
457    /**
458     * Returns true if the form is a form to fill out.
459     * 
460     * @return if the form is a form to fill out.
461     */
462    private boolean isFormType() {
463        return DataForm.Type.form == dataForm.getType();
464    }
465
466    /**
467     * Returns true if the form is a form to submit.
468     * 
469     * @return if the form is a form to submit.
470     */
471    private boolean isSubmitType() {
472        return DataForm.Type.submit == dataForm.getType();
473    }
474
475    /**
476     * Returns a new Form to submit the completed values. The new Form will include all the fields
477     * of the original form except for the fields of type FIXED. Only the HIDDEN fields will 
478     * include the same value of the original form. The other fields of the new form MUST be 
479     * completed. If a field remains with no answer when sending the completed form, then it won't 
480     * be included as part of the completed form.<p>
481     * 
482     * The reason why the fields with variables are included in the new form is to provide a model 
483     * for binding with any UI. This means that the UIs will use the original form (of type 
484     * "form") to learn how to render the form, but the UIs will bind the fields to the form of
485     * type submit.
486     * 
487     * @return a Form to submit the completed values.
488     */
489    public Form createAnswerForm() {
490        if (!isFormType()) {
491            throw new IllegalStateException("Only forms of type \"form\" could be answered");
492        }
493        // Create a new Form
494        Form form = new Form(DataForm.Type.submit);
495        for (FormField field : getFields()) {
496            // Add to the new form any type of field that includes a variable.
497            // Note: The fields of type FIXED are the only ones that don't specify a variable
498            if (field.getVariable() != null) {
499                FormField newField = new FormField(field.getVariable());
500                newField.setType(field.getType());
501                form.addField(newField);
502                // Set the answer ONLY to the hidden fields 
503                if (field.getType() == FormField.Type.hidden) {
504                    // Since a hidden field could have many values we need to collect them 
505                    // in a list
506                    List<String> values = new ArrayList<String>();
507                    for (String value : field.getValues()) {
508                        values.add(value);
509                    }
510                    form.setAnswer(field.getVariable(), values);
511                }
512            }
513        }
514        return form;
515    }
516
517}