datepickertag.java

一个很好的开源项目管理系统源代码

package net.java.workeffort.infrastructure.jsptags;

import java.util.Locale;

import javax.servlet.jsp.JspException;

import net.java.htmltag.BaseInputTag;

import org.apache.commons.lang.StringUtils;
import org.springframework.context.MessageSource;
import org.springframework.context.NoSuchMessageException;
import org.springframework.ui.context.Theme;
import org.springframework.web.util.ExpressionEvaluationUtils;

/**
 * Custom date picker tag.
 * <p>
 * Uses the CalendarPopup.js javascript code written by Matt Kruse
 * (www.mattkruse.com). The javascript has been modified to produce xhtml
 * compliant code for the calendar and hide the select boxs which show through.
 * The tag supports i18n.
 * <p>
 * See workeffort.tld for attribute list.
 * <p>
 * The 'formName' attribute should *match* the 'name' attribute of the 'form'
 * tag in your jsp and is required for the javascript to set the value on the
 * appropriate text field.
 * <p>
 * The date format is picked up from message resources. The message resource
 * file should have an entry for 'dataFormat'.
 * <p>
 * The date picker image is picked up from the theme properties file. The file
 * should have an entry for 'datePicker.img'
 * <p>
 * Select boxes have a nasty way of showing through when overlayed by other
 * layers.The 'hideSelect' attribute hides these select boxes using javascript.
 * The default value for this attribute is 'true'.
 * <p>
 * I18n: Creates the javascript to internationalize date picker from information
 * in the message resources file. Sets month names, day headers and translation
 * for 'Today' Make sure that in the message resources file
 * datePicker.monthNames datePicker.dayHeaders and datePicker.todayText are set
 * appropriately if you want an Non English version.
 * <p>
 * Note: When the tag is used in multi row forms you may want to set the
 * 'hideSelect' parameter to 'false'. Other wise, the rendering of the form will
 * be slow due to the amount of work the javascript has to do. When the
 * 'hideSelect' parameter is false, design the layout in such a way that the
 * datePickers do not overlay 'select' boxes.
 * @author Antony Joseph
 */

public class DatePickerTag extends BaseInputTag {
    // TAG ATTRIBUTES
    /** dateFormat. the date format */
    private String formName;
    private String hideSelect = "true";

    /**
     * @see javax.servlet.jsp.tagext.Tag#doStartTag()
     */
    public int doStartTagInternal() throws JspException {
        formName = ExpressionEvaluationUtils.evaluateString("formName",
                formName, pageContext);

        hideSelect = ExpressionEvaluationUtils.evaluateString("hideSelect",
                hideSelect, pageContext);
        setReadonly(ExpressionEvaluationUtils.evaluateString("readonly",
                getReadonly(), pageContext));
        setDisabled(ExpressionEvaluationUtils.evaluateString("disabled",
                getDisabled(), pageContext));

        // set the type of the input element.
        setType("text");

        StringBuffer js = new StringBuffer();
        MessageSource messageSource = getMessageSource();

        String div = createDivId();

        String calendar = div + "Calendar";
        String anchor = div + "Anchor";

        // create the javacript snippet needed for each date picker.
        js.append("<script type=\"text/javascript\"> \n");
        js.append("// <![CDATA[\n");
        // for xhtml compliance
        js.append("var ");
        js.append(calendar);
        js.append("= new CalendarPopup('");
        js.append(div);
        // The default is any select boxes which falls within the area of
        // the calendar will be hidden.
        if ("false".equals(hideSelect))
            js.append("', 'false'); \n");
        else
            js.append("'); \n");

        datePickerI18n(js, messageSource, calendar);
        js.append(" // ]]>\n");
        js.append("</script>\n");

        if (getMaxlength() == null)
            setMaxlength(getSize());

        js.append(renderInputElement());

        js.append("\n<input type=\"image\" src=\"");
        js.append(getImageSrc());
        js.append("\" onclick=\"");
        js.append(calendar);
        js.append(".select(document.");
        js.append(formName);
        js.append("[\'");
        js.append(getProperty());
        js.append("']");
        js.append(",'");
        js.append(anchor);
        js.append("','");
        js.append(getDateFormat());
        js.append("'); return false; \" id=\"");
        js.append(anchor);
        js.append("\"");
        // disable the button as needed
        if ("true".equals(getReadonly()) || "true".equals(getDisabled())) {
            js.append(" disabled=\"disabled\" ");
        }
        js.append("/>\n");
        js.append("<div id=\"");
        js.append(div);
        js
                .append("\" style=\"position:absolute;visibility:hidden;background-color:white;layer-background-color:white;\"></div> \n");
        write(js.toString());

        return SKIP_BODY;
    }

    /**
     * Resets attribute values for tag reuse.
     */
    public void release() {
        super.release();
        formName = null;
        hideSelect = "true";
    }

    /**
     * Creates the javascript to internationalize date picker from information
     * in the MessageResources bundle file. Sets month names, day headers and
     * translation for 'Today' Make sure that in the properties file
     * datePicker.monthNames datePicker.dayHeaders and datePicker.todayText are
     * set appropriately if you want an Non English version.
     * @param messageResources The message resource
     * @param calendar The calendar javascript variable name.
     * @return js The javascript code to internationalize the date picker.
     */
    private void datePickerI18n(StringBuffer buffer,
            MessageSource messageSource, String calendar) {
        Locale locale = getRequestContext().getLocale();
        try {
            // If the month names are present than we need to do i18n
            String monthNames = messageSource.getMessage(
                    "datePicker.monthNames", null, locale);

            buffer.append(calendar);
            buffer.append(".setMonthNames(");
            buffer.append(monthNames);
            buffer.append(");");
            buffer.append(calendar);
            buffer.append(".setDayHeaders(");
            buffer.append(messageSource.getMessage("datePicker.dayHeaders",
                    null, locale));
            buffer.append(");");
            buffer.append(calendar);
            buffer.append(".setTodayText(\"");
            buffer.append(messageSource.getMessage("datePicker.todayText",
                    null, locale));
            buffer.append("\");");
        }
        catch (NoSuchMessageException e) {
            // Not i18n for calender. Do nothing.
        }
    }

    /**
     * @return Returns the formName.
     */
    public String getFormName() {
        return formName;
    }

    /**
     * @param formName The formName to set.
     */
    public void setFormName(String formName) {
        this.formName = formName;
    }

    /**
     * @return Returns the hideSelect.
     */
    public String getHideSelect() {
        return hideSelect;
    }

    /**
     * @param hideSelect The hideSelect to set.
     */
    public void setHideSelect(String hideSelect) {
        this.hideSelect = hideSelect;
    }

    private String createDivId() {
        String property = getProperty();
        return StringUtils.replaceChars(property, "[].", null) + "Div";
    }

    private String getDateFormat() {
        return getMessageSource().getMessage("dateFormat", null,
                getRequestContext().getLocale());
    }

    private String getImageSrc() {
        Locale locale = getRequestContext().getLocale();
        Theme theme = getRequestContext().getTheme();
        if (theme != null)
            return theme.getMessageSource().getMessage("datePicker.img", null,
                    locale);
        else
            return null;
    }

    /**
     * @return Returns the errorStyleClass.
     */
    public String getErrorStyleClass() {
        return (getStyleClass() == null) ? null : getStyleClass() + "Error";
    }
}