/Custom ODB tree

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Purpose

The /Custom ODB tree is required if the user wishes to create mhttpd custom pages. It contains essential data needed for mhttpd to display a custom page. The /images subtree is required if an imagefile (*.gif) is to be displayed on the custom page. Optionally, labels, bars and fills can be superimposed on the image.

Creating the /Custom tree

The /Custom ODB tree is an optional tree that may be created by the user.


Keys in the /Custom tree

The optional ODB /Custom tree may contain any of the following :

  • keys pointing to local external files containing custom web pages (html/javascript files)
  • keys pointing to local external files containing resources for custom web pages (e.g. .css style files, .js javascript file, images).
    • Note: files that are have a '.' in the Key name are assumed to be resource files and are treated differently. See also the Path key notes below.
    • Note: .css, .js, .pdf, .jpg, .gif, .png, .svg, .ps, .eps, .xls, .doc, .txt, .asc, .zip files should get served up with the correct MIME types
  • keys containing the html code for internal custom webpages
  • Path variable, used to indicate where to look on host machine for external files.
  • /pwd subtree used to contain custom password keys
  • /images subtree used to specify images for custom pages

Keys defined in this tree pointing to custom web pages of any kind are called custom-links.

  • External custom-links contain the path and filename of the external custom page file (or may be a symbolic link to a custom-link)
  • Internal custom-links contain the code for an Internal Custom Page.

If custom-links are defined in this tree, except where noted below, the custom-links will appear as custom-buttons on the mhttpd Status Page. By clicking on one of these custom-buttons, the custom page will be visible in a new frame (see also Key names).

We will note some of the subtleties of how the Custom tree keys are used in the following sub-sections.

Key names

The user chooses the names of any keys in the /Custom ODB tree except for

  • the key name Status is reserved (see Custom Status Page).
  • the key name pwd is reserved (see optional Pwd subtree for custom passwords)
  • the key name Path is reserved (see optional [[#Path key|Path key] for details)
  • keys in the /images subtree have defined names except for the user-defined <Image-name> subtree.


There are two characters that have special meaning if they are the last character of a custom-link in the /Custom tree :

  • The character "&" forces the page to be opened within the current frame when the custom-button is pressed. If this character is omitted, the page will be opened in a new frame. The "&" character is omitted from the name of the button.
  • The character "!" suppresses the custom-button from appearing on the Status Page, forming a hidden-link.

The hidden-link feature can be used to provide external webpages hidden from the user, such as a stylesheet or a file of Javascript functions needed by other custom pages.

The /Custom tree in the example below would produce one custom-button, i.e. ppg cycle.

NOTE
To avoid confusion, do not use custom-links that only differ by the special characters "&" and "!" (e.g. "test", "test&" and "test!") in the same ODB.

Path key

When creating custom external web pages you will usually want to use other resource files, like CSS style sheets or images.

One way to do that is to specify each of the files that you need to use in the /Custom tree. For instance, suppose you had a HTML file called control.html that used an image called valve.png. You could 

Key name                        Type    #Val  Size  Last Opn Mode Value
---------------------------------------------------------------------------
Control                         STRING  1     256   1h   0   RWD  /home/expt/online/custom/control.html
valve.png!                      STRING  1     256   1h   0   RWD  /home/expt/online/custom/valve.png

You would then be able to refer to that png normally in your HTML 

...
<img src="valve.png!">
...

This approach can get tedious however, if you have a large number of resource files to add.

An alternative is given by the Path ODB key. This key can be used to specify a directory on the server file system where files should be searched for. So, for instance, if the /Custom tree is set to 

Key name                        Type    #Val  Size  Last Opn Mode Value
---------------------------------------------------------------------------
Path                            STRING  1     256   1h   0   RWD  /home/expt/online/custom/
Control                         STRING  1     256   1h   0   RWD  control.html

you can instruct mhttpd to look in the directory /home/expt/online/custom/ and then map the custom page 'Control' to

/home/expt/online/custom/control.html.

One very important point: when the key /Custom/Path is defined, mhttpd will treat differently how it serves up resources, depending on whether there is a '.' in the resource web address. So, for instance, for the custom page described above 

     https://myhost:8443/?cmd=custom&page=Control   
 or  http://myhost:8081/CS/Control   (very old MIDAS versions )

you will need to have a ODB key called /Custom/Control, as described above.

However, if you have the ODB key /Custom/Path and you access content like 

   https://myhost:8443/?cmd=custom&page=valve.png
or http://myhost:8081/CS/valve.png (very old MIDAS versions )

then mhttpd will automatically figure out that it should use the file 

Value of "/Custom/Path" + valve.png
i.e. /home/expt/online/custom/valve.png

So the benefit is that with the /Custom/Path key set, you can just place all your resource files in the directory pointed to by /Custom/Path and mhttpd will find them, without needing to specify them individually /Custom as custom-links.

See also Custom Page Features#Resource files for more examples.

Example

The following example using the odbedit ls command shows the optional custom tree for an experiment.
Note the use of the "&" and "!" characters in the names of the custom keys (see key names for details). 

[local:pol:S]/ls -lr /Custom
Key name                        Type    #Val  Size  Last Opn Mode Value
---------------------------------------------------------------------------
custom                          DIR
   ppg_cycle&                  STRING  1    80    36h  0  RWD  /home/pol/online/pol/custom/pol_sc.html
   pol_functions!              STRING  1    80    36h  0  RWD  /home/pol/online/pol/custom/pol_functions.js
   style!                      STRING  1    80    36h  0  RWD  /home/pol/online/pol/custom/style.css
   images                      DIR
       pol_sc.gif              DIR
           background          STRING  1     80    36h  0   RWD  /home/pol/online/pol/custom/pol_sc.gif
           labels              DIR
               num bins        DIR
                   Src         STRING  1     256   36h  0   RWD  /Equipment/pol_acq/settings/output/num bins per cycle
                   Format      STRING  1     32    36h  0   RWD  %d
                   Font        STRING  1     32    36h  0   RWD  Medium
                   X           INT     1     4     36h  0   RWD  315
                   Y           INT     1     4     36h  0   RWD  502
                   Align       INT     1     4     36h  0   RWD  0
                   FGColor     STRING  1     8     36h  0   RWD  FFFFFF
                   BGColor     STRING  1     8     36h  0   RWD  0000FF
               dwell time      DIR
                   Src         STRING  1     256   36h  0   RWD  /Equipment/POL_ACQ/Settings/input/dwell time (ms)
                   Format      STRING  1     32    36h  0   RWD  %f ms
                   Font        STRING  1     32    36h  0   RWD  large
                   X           INT     1     4     36h  0   RWD  145
                   Y           INT     1     4     36h  0   RWD  430
                   Align       INT     1     4     36h  0   RWD  0
                   FGColor     STRING  1     8     36h  0   RWD  FFFFFF
                   BGColor     STRING  1     8     36h  0   RWD  0000FF
            fills              DIR
                   SSLevelBox  DIR
                   Src         STRING  1     256   36h  0   RWD  /Equipment/TpcGasPlc/GasCalc/Calculated[136]
                   X           INT     1     4     36h  0   RWD  578
                   Y           INT     1     4     36h  0   RWD  490
                   Limits      DOUBLE  3     8     2s   0   RWD
                                       [0]             0
                                       [1]             1
                                       [2]             2
                   Fillcolors  STRING  4     8     2s   0   RWD
                                       [0]             000000
                                       [1]             00FF00
                                       [2]             808080
            bars               DIR
                   temp        DIR
                   Src         STRING  1     256   36h  0   RWD  /Equipment/Temperature/Variables/Readback[5]
                   X           INT     1     4     36h  0   RWD  42
                   Y           INT     1     4     36h  0   RWD  68
                   Width       INT     1     4     36h  0   RWD  10
                   Height      INT     1     4     36h  0   RWD  50
                   Direction   INT     1     4     36h  0   RWD  0
                   Axis        INT     1     4     36h  0   RWD  1
                   Logscale    BOOL    1     4     >99d 0   RWD  n
                   Min         DOUBLE  1     8     >99d 0   RWD  0
                   Max         DOUBLE  1     8     >99d 0   RWD  0
                   FGcolor     STRING  1     8     2s   0   RWD  000000
                   BGcolor     STRING  1     8     2s   0   RWD  FFFFFF
                   BDcolor     STRING  1     8     2s   0   RWD  808080



Pwd subtree

  • Type: DIR

This optional subtree in the /Custom ODB tree is created by the user if Custom Page write access is to be password protected.

<password>

  • Type: STRING
  • Default: ""

The name of the optional key(s) in the /Pwd subtree defines a password that the user must specify to gain access to a password-protected item on a Custom Page.

Password examples

If the password is CustomPwd, the ODB key /Custom/Pwd/CustomPwd would be defined.

By using an explicit name, one can use a single password for all controls on a page, or one could use several passwords on the same page. For example, a shift crew password for the less severe controls could be defined as ShiftPwd, and an "expert" password ExpertPwd for the critical things.

In this case, the ODB would have two passwords defined, i.e. 

/Custom/Pwd/ExpertPwd
/Custom/Pwd/ShiftPwd

The password is of course not secure in the sense that it is placed in plain text into the ODB, but its purpose is to prevent accidental modification, rather than malicious interference.



Images subtree

  • Type: DIR

This optional subtree in the /Custom ODB tree is created by the user. It is required if an imagefile (*.gif) is to be displayed on a custom page. This subtree is also required for any labels, bars or fills to be superimposed on the image.



<Image-name> subtree

  • Type: DIR
  • Default:

User-created subdirectory usually named for the corresponding gif-image, e.g. "pol_sc.gif" in the example above. For multiple images, multiple subdirectories may be defined. The user chooses the name of this key.



Background

  • Type: STRING
  • Default:

This key in the <image-name> subtree contains the path and filename of the image file to be loaded into a custom page. Only gif format is supported for the image. This optional key is created by the user.




Labels subtree

  • Type: DIR
  • Default:

User-created subdirectory in the <image-name> subtree required if labels are to be superimposed on an image on a custom page.




<label-name> subtree

  • Type: DIR
  • Default:

User-created subdirectory in the Labels subtree containing keys to define this label as listed below. There will be a <label-name> subtree for each label superimposed on the custom image.

The user creates keys in this subtree with the names and types as listed below. See also the example above.


Src
  • Type: STRING [256]
  • Default:

This key in the <label-name> subtree contains the path of a valid ODB Key variable. This is the value to be used for this label on an image.




Format
  • Type: STRING [32]
  • Default: "%1.1f"

This key in the <label-name> subtree contains the format for this label on the image. Format specifications (c.f. "printf" in C) are used to convert the value specified by the Src key into the output string that appears on the image. For example,

  • "Count Rate:%5d kB/s" used to display an integer value
  • "%5.2f%% iBu" used to display a floating point value. Note "%%" displays the "%" sign.





Font
  • Type: STRING[32]
  • Default: "Medium"

This key in the <label-name> subtree contains the font size for this label. Supported values are "small", "medium" or "giant".




X
  • Type: INT
  • Default: 0

This key in the <label-name> subtree contains the X position for this label in pixels.



Y
  • Type: INT
  • Default: 0

This key in the <label-name> subtree contains the Y position for this label in pixels.




Align
  • Type: INT
  • Default: 0

This key in the <label-name> subtree contains an integer representing Horizontal Alignment for this label. Set to one of 0 (left), 1 (center) or 2 (right).




FGColor
  • Type: STRING [8]
  • Default: "000000"

This key in the <label-name> subtree contains the foreground colour for this label in the format RRGGBB (hex). See colour table.





BGColor
  • Type: STRING [8]
  • Default: "FFFFFF"

This key in the <label-name> subtree contains the background colour for this label in the format RRGGBB (hex). See colour table.





Bars subtree

  • Type: DIR
  • Default:

User-created subdirectory in the <image-name> subtree required if bars are to be superimposed on an image on a custom page.






<bar-name> subtree

  • Type: DIR
  • Default:

User-created subdirectory in the Fills subtree containing keys to define this bar as listed below. There will be a <bar-name> subtree for each bar superimposed on the custom image.

The user creates keys in this subtree with the names and types as listed below. See also the example above.


Src
  • Type: STRING [256]
  • Default:

This key in the <bar-name> subtree contains the path of a valid ODB Key variable. This is the value to be used for this bar.




X
  • Type: INT
  • Default: 0

This key in the <bar-name> subtree contains the X position for this bar in pixels.



Y
  • Type: INT
  • Default: 0

This key in the <bar-name> subtree contains the Y position for this bar in pixels.




Width
  • Type: INT
  • Default: 10

This key in the <bar-name> subtree contains the width of this bar in pixels.




Height
  • Type: INT
  • Default: 100

This key in the <bar-name> subtree contains the height of this bar in pixels.



Direction
  • Type: INT
  • Default: 0

This key in the <bar-name> subtree contains an integer denoting the direction of this bar. It can be either 0 (vertical) or 1 (horizontal).




Axis
  • Type: INT
  • Default: 1

This key in the <bar-name> subtree contains an integer specifying the axis of this bar. It can be either 0 (none), 1 (left) or 2 (right).



Logscale
  • Type: BOOL
  • Default: "n"

This key in the <bar-name> subtree specifies whether the axis of this bar is logarithmic. Set to "y" for logarithmic, otherwise "n".



Min
  • Type: DOUBLE
  • Default: 0

This key in the <bar-name> subtree contains the minimum value for the axis of the bar.




Max
  • Type: DOUBLE
  • Default: 10

This key in the <bar-name> subtree contains the maximum value for the axis of the bar.




FGColor
  • Type: STRING [8]
  • Default: "000000"

This key in the <bar-name> subtree contains the foreground colour for this bar in the format RRGGBB (hex). See colour table.





BGColor
  • Type: STRING [8]
  • Default: "FFFFFF"

This key in the <bar-name> subtree contains the background colour for this bar in the format RRGGBB (hex). See colour table.




BDColor
  • Type: STRING [8]
  • Default: "808080"

This key in the <bar-name> subtree contains the border colour for this bar in the format RRGGBB (hex). See colour table.




Fills subtree

  • Type: DIR
  • Default:

User-created subdirectory in the <image-name> subtree required if fills are to be superimposed on an image on a custom page. A "fill" can change the colour of a region on the image. The contents of the ODB key defined in Src determines the colour as defined by the Limits and Fillcolors arrays.




<fill-name> subtree

  • Type: DIR
  • Default:

User-created subdirectory in the Fills subtree containing keys to define this fill as listed below. There will be a <fill-name> subtree for each fill superimposed on the custom image.

The user creates keys in this subtree with the names and types as listed below. See also the example above.


Src
  • Type: STRING
  • Default:

This key in the <fill-name> subtree contains the path of a valid ODB Key variable. Unless a logic calculation is included, the contents of this key determines the value used for the fill on the image defined by the key Background (see fill-name "SSLevelBox" in the example above).

If a logic calculation is included, up to two operators are permitted, and they must be either

">>" (shift to the right) or
"&" (bitwise AND).

A hexadecimal number preceded by "0x" is also supported. This feature enables a SRC key that is actually a bit pattern to be used for a fill.

In the following example, a gas valve is open if bit 14 of PLCR[136] is TRUE and closed if bit 15 is TRUE (bits are from 0-15). The contents of PLCR[136] are shifted to the right by 14 and then a logical AND is performed to clear all but the lowest 2 bits. The result is used to colour the valve body lime green if the valve is open, and black if it is closed. If neither bit is set (i.e. the valve is neither open nor closed) the valve body is coloured red to indicate an error. Anything else (i.e. both bits TRUE) will give a gray colour. 

[local:t2kgas:S]/>ls /custom/images/Pump_20.gif/fills/d2vb3
Src                             /Equipment/TpcGasPlc/Variables/PLCR[136] >> 14 & 0x3
X                               905
Y                               536
limits
                               0
                               1
                               2
                               3
Fillcolors
                               808080
                               00FF00
                               000000
                               808080

Any fill that requires a more complicated calculation than this will have to be done using Javascript in the custom page. The calculated value can then be stored in an ODB key, which is then defined as a Fill Src key.



X
  • Type: INT
  • Default:

This key in the <fill-name> subtree contains the X position for this fill in pixels.



Y
  • Type: INT
  • Default:

This key in the <fill-name> subtree contains the Y position for this fill in pixels.




Limits
  • Type: INT array
  • Default:

This key in the <fill-name> subtree is a variable-length array containing the values of the limits that when reached cause a colour change. Array length must match length of array Fillcolors.




Fillcolors
  • Type: INT array
  • Default:

This key in the <fill-name> subtree is a variable-length array containing the colours corresponding to the Limits array. The colours are defined in the format RRGGBB (hex). See colour table. Array length must match length of Limits array.






Colour Table

For convenience, a colour reference table is shown here for some common colours:

Colour RGB Value
Black 000000
White FFFFFF
Red FF0000
Lime green 00FF00
Blue 0000FF
Yellow FFFF00
Grey 808080
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