[Indigo]<Squirrel>NewTop>TuplesEditorImpl.mesa!1

File: TuplesEditorImpl.mesa

Created by Donahue November 16, 1982 2:38 pm

Last edited by:

Donahue, April 14, 1983 10:15 am

Cattell, June 24, 1983 3:09 pm

Butler, June 20, 1984 4:46:37 pm PDT

Last Edited by: Beach, March 28, 1984 9:25:58 pm PST

DIRECTORY

Atom USING [GetPropFromList],

BasicTime USING [GMT],

Buttons USING [ButtonProc, ReLabel],

DB,

DBEnvironment,

IO,

Menus USING[ MouseButton ],

Nut,

NutOps,

NutViewer USING [Error, Message],

Rope,

TuplesEditor,

VFonts USING[CharWidth, FontHeight],

ViewerOps USING [AddProp, FetchProp, FetchViewerClass, PaintViewer],

Containers,

ViewerTools USING [GetContents, SetContents, SetSelection],

ViewerClasses, VTables;

TuplesEditorImpl: CEDAR MONITOR

IMPORTS

Atom, Buttons, DB, DBEnvironment, IO, Nut, NutOps,

NutViewer, Rope, VTables, VFonts, ViewerOps, ViewerTools

EXPORTS TuplesEditor =

{ OPEN DB, Rope, Nut, ViewerClasses, VTables;

PosPair: TYPE = RECORD[ row: CARDINAL, col: CARDINAL];

anyErrors: BOOL; -- Set if any procedure discovered user errors in saving the new entries

defaultOld: PUBLIC BOOL← TRUE; -- FALSE => attributes start in NewOrOld mode, else OldOnly

updateList: AttributeValueList;

allFieldsNull: BOOLEAN;

relTable: Viewer;

relRows: CARDINAL;

newRelship, oldRelship: Relship;

DisplayTuples: PUBLIC ENTRY PROC[e: Entity, attrList: AttributeList, parent: Viewer]

RETURNS[ TuplesTable: VTable ] =

Main procedure in this module: puts up a subviewer in the parent viewer containing

all the tuples that do or could refer to the entity e. Main loop goes through all

attributes potentially referencing e's domain, and calls AddRow to add a blank tuple

if the tupleList referencing e is empty for that attribute, or the tupleList if it is

not empty.

{ ENABLE UNWIND => NULL;

row: CARDINAL ← 0;

TuplesTable ← Create[ parent: parent, rows: Length[attrList]+1, columns: 1 ];

FOR attrL: AttributeList ← attrList, attrL.rest UNTIL attrL = NIL DO

{ tupleList: LIST OF Relship = IF e = NIL THEN NIL ELSE NutOps.GetTuples[e, attrL.first];

relTable: VTable = Create[ rows: 1, columns: 3, parent: TuplesTable ];

IF tupleList = NIL THEN AddRow[ relTable, attrL.first ]

ELSE

FOR tlT: LIST OF Relship ← tupleList, tlT.rest UNTIL tlT=NIL DO

AddRow[ relTable, attrL.first, tlT.first ] ENDLOOP;

SetTableEntry[table: TuplesTable, row: row, flavor: $Viewer,

clientData: relTable, border: NullBorder ];

row ← row+1 }

ENDLOOP;

ViewerOps.AddProp[ TuplesTable, $Entity, e ];

Install[TuplesTable, FALSE] };

SpawnParent: PROC[ v: Viewer ] RETURNS [ parent: Viewer ] = {

parent ← v;

WHILE parent.parent # NIL DO parent ← parent.parent ENDLOOP };

AddRow: PROC[ table: VTable, attribute: Attribute, relship: Relship ← NIL ] =

Add a row to the table, where the entity being displayed is assumed to be the value of

the attribute supplied. If a relship is supplied, take the values of the other fields from it;

otherwise, display empty fields.

{ row: CARDINAL ← GetRowsAndColumns[table: table].rows-1;

r: Relation = NutOps.GetRelation[attribute];

allAttrs: LIST OF Attribute ← NutOps.AttributesOf[r];

firstRow: BOOLEAN ← TRUE;

displayAttrs: LIST OF Attribute = NutOps.RemoveAttribute[attribute, allAttrs];

howLong: INT = Length[displayAttrs];

howMuchSpace: INT = IF howLong MOD 2 = 0 THEN howLong/2 ELSE (howLong/2)+1;

i: INT ← 1; -- the index of the next column to be updated

The structure of the table now is to have three columns; the first is the name of the relation

(or blank if in succeeding rows), while the second and third give two attributes of the

relation

set the first entry

SetTableEntry[ table: table, row: row, column: 0, flavor: $Button, name: GetName[r],

clientData: attribute, proc: RelProc, border: NullBorder ];

{ relViewer: Viewer = GetTableEntry[ table: table, row: row, column: 0 ];

ViewerOps.AddProp[ relViewer, $newLine, NEW[BOOLEAN ← TRUE] ];

ViewerOps.AddProp[ viewer: relViewer, prop: $relShip, val: relship ];

ViewerOps.AddProp[ viewer: relViewer, prop: $r, val: r];

ViewerOps.AddProp[ viewer: relViewer, prop: $a, val: attribute ];

ViewerOps.AddProp[ viewer: relViewer, prop: $row, val: NEW[ INT ← row ] ] };

expand the table to contain as many rows as it will need for the display attributes

SetRowsAndColumns[ table: table, rows: row+1+howMuchSpace, columns: 3 ];

FOR da: LIST OF Attribute ← displayAttrs, da.rest UNTIL da = NIL DO

nextAttr: Attribute = da.first;

attrViewer: VTable = Create[ parent: table, columns: 4 ];

ViewerOps.AddProp[ attrViewer, $attr, nextAttr ];

ViewerOps.AddProp[ attrViewer, $which, NEW[ INT← IF defaultOld THEN 2 ELSE 0 ] ];

VTables.SetTableEntry[

table: attrViewer, column: 0, flavor: $Button, proc: AttrProc,

clientData: attrViewer, name: Rope.Cat[DB.NameOf[nextAttr], ":"], border: NullBorder];

IF NutOps.EntityValued[nextAttr] THEN

{ VTables.SetTableEntry[ table: attrViewer, column: 2, name: IF defaultOld THEN "O" ELSE "",

flavor: $Button, w: VFonts.CharWidth['O]+5, border: NullBorder,

clientData: attrViewer, proc: CycleNewOld ];

VTables.GetTableEntry[ table: attrViewer, column: 2].border ← TRUE };

VTables.SetTableEntry[ table: attrViewer, column: 3, useMaxSize: TRUE, border: NullBorder,

w: 20*VFonts.CharWidth['A], flavor: $Text ];

VTables.GetTableEntry[ table: attrViewer, column: 3 ].scrollable ← TRUE;

IF relship # NIL THEN

ViewerTools.SetContents[ viewer: GetTableEntry[ table: attrViewer, column: 3 ],

contents: GetFS[ relship, nextAttr ], paint: FALSE ];

Install[ attrViewer, FALSE ];

VTables.SetTableEntry[ table: table, row: row, column: i, flavor: $Viewer, clientData: attrViewer,

border: NullBorder, useMaxSize: TRUE ];

i ← (i+1) MOD 3;

IF i = 0 THEN -- it's time for a new row

{ row ← row + 1;

SetTableEntry[ table: table, row: row, column: 0, name: "", border: NullBorder ];

ViewerOps.AddProp[ GetTableEntry[ table, row, 0 ], $newLine, NEW[BOOLEAN ← FALSE] ];

i ← i+1 }

ENDLOOP;

VTables.Install[ table, FALSE ] };

Length: PROC[ l: LIST OF Attribute ] RETURNS[ n: INT ] =

{ n ← 0; UNTIL l = NIL DO n ← n+1; l ← l.rest ENDLOOP };

AttrProc: Buttons.ButtonProc = TRUSTED

{ viewer: ViewerClasses.Viewer = NARROW[ parent, ViewerClasses.Viewer ];

attrViewer: VTable = NARROW[ clientData, VTable ];

textViewer: Viewer = GetTableEntry[ table: attrViewer, column: 3 ];

attr: Attribute = V2E[ViewerOps.FetchProp[attrViewer, $attr]];

domain: Domain = V2E[GetP[attr, aTypeIs, aTypeOf]];

entity: Entity;

SELECT mouseButton FROM

Menus.MouseButton[red] =>

ViewerTools.SetSelection[ textViewer, NIL ];

Menus.MouseButton[yellow] =>

{ entity ← DeclareEntity[ domain, ViewerTools.GetContents[textViewer], Version[OldOnly] !

DB.Error => { entity ← NIL; CONTINUE } ];

IF entity # NIL THEN
[] ← Nut.Display[ eName: DB.NameOf[entity], domain: DB.NameOf[domain], segment: DB.SegmentOf[entity], parent: SpawnParent[viewer] ]

ELSE NutViewer.Message[viewer, ViewerTools.GetContents[textViewer], " not found!"] };

ENDCASE => ViewerTools.SetSelection[ textViewer, NIL ] };

RelProc: Buttons.ButtonProc = TRUSTED

{ viewer: ViewerClasses.Viewer = NARROW[ parent, ViewerClasses.Viewer ];

attribute: Attribute = V2E[clientData];

relTable: VTable ← viewer.parent;

TuplesTable: VTable = relTable.parent;

SELECT mouseButton FROM

Menus.MouseButton[red] =>

{ u: Uniqueness = V2U[GetP[attribute, aUniquenessIs, aUniquenessOf]];

IF u = Key OR u = OptionalKey THEN

{anyErrors← TRUE; NutViewer.Message[viewer, "Only one allowed!"]}

ELSE AddRow[ relTable, attribute ] };

Menus.MouseButton[blue] =>

{ row: INT ← (NARROW[ ViewerOps.FetchProp[ viewer, $row ], REF INT ])^;

newLine: BOOLEAN ← FALSE;

UNTIL newLine DO

FOR i: NAT IN [0..2) DO

{ attrViewer: VTable = GetTableEntry[ relTable, row, i+1 ];

IF attrViewer # NIL THEN

{ textViewer: Viewer ← GetTableEntry[ attrViewer, 0, 3 ];

attrButton: Viewer ← GetTableEntry[ attrViewer, 0, 0 ];

xoff, yoff: INTEGER;

text: ROPE = ViewerTools.GetContents[ textViewer ];

textHeight: INT = textViewer.wh;

newTextViewer: Viewer;

[xoff, yoff] ← GetEntryOffset[ table: relTable, row: row, column: 0 ];

SetTableEntry[ table: attrViewer, column: 3, flavor: $Text, border: NullBorder, useMaxSize: TRUE, w: 20*VFonts.CharWidth['A], h: textHeight+VFonts.FontHeight[]+1 ];

newTextViewer ← GetTableEntry[ table: attrViewer, column: 3 ];

newTextViewer.scrollable ← TRUE;

ViewerTools.SetContents[ viewer: newTextViewer, contents: text, paint: FALSE ];

Install[ attrViewer, FALSE ];

newTextViewer.newVersion ← textViewer.newVersion;

SetEntryOffset[ table: relTable, row: row, column: 0, yoff: GetEntryOffset[ table: attrViewer, column: 0 ].yoff ];

Install[ relTable, FALSE ] } }

ENDLOOP;

row ← row + 1;

IF row = GetRowsAndColumns[relTable].rows-1 THEN EXIT;

{ relViewer: VTable = GetTableEntry[ relTable, row, 0 ];

newLineProp: REF BOOLEAN =

IF relViewer = NIL THEN NIL

ELSE NARROW[ViewerOps.FetchProp[relViewer, $newLine]];

newLine ← IF newLineProp = NIL THEN TRUE ELSE newLineProp^ }

ENDLOOP;

Install[ relTable, FALSE ] };

Menus.MouseButton[yellow] =>

{ row: INT ← (NARROW[ ViewerOps.FetchProp[ viewer, $row ], REF INT ])^;

newLine: BOOLEAN ← FALSE;

UNTIL newLine DO

FOR i: NAT IN [0..2) DO

{ attrViewer: VTable = GetTableEntry[ relTable, row, i+1 ];

IF attrViewer # NIL THEN

{ attr: Attribute = V2E[ViewerOps.FetchProp[attrViewer, $attr]];

type: Entity = V2E[GetP[attr, aTypeIs, aTypeOf]];

SetTableEntry[ table: attrViewer, row: 0, column: 1, name: TypeLabel[type], border: NullBorder ];

Install[ attrViewer, FALSE ] } }

ENDLOOP;

row ← row + 1;

IF row = GetRowsAndColumns[relTable].rows-1 THEN EXIT;

{ relViewer: VTable = GetTableEntry[ relTable, row, 0 ];

newLineProp: REF BOOLEAN =

IF relViewer = NIL THEN NIL

ELSE NARROW[ViewerOps.FetchProp[relViewer, $newLine]];

newLine ← IF newLineProp = NIL THEN TRUE ELSE newLineProp^ }

ENDLOOP;

Install[ relTable, FALSE ] };

ENDCASE;

InstallAll[ TuplesTable] };

InstallAll: PROC[ viewer: Viewer ] = {

tableClass: ViewerClasses.ViewerClass = ViewerOps.FetchViewerClass[$VTable];

IF viewer = NIL THEN RETURN;

UNTIL viewer.parent = NIL DO

IF viewer.class = tableClass THEN Install[viewer, FALSE];

viewer ← viewer.parent;

ENDLOOP;

ViewerOps.PaintViewer[viewer, all] };

TypeLabel: PROC[ type: Entity ] RETURNS[ Rope.ROPE ] =

{ IF DB.Eq[type, DB.RopeType] THEN RETURN["(String)"]

ELSE IF DB.Eq[type, DB.IntType] THEN RETURN["(Int)"]

ELSE IF DB.Eq[type, DB.BoolType] THEN RETURN["(Bool)"]

ELSE IF DB.Eq[type, DB.TimeType] THEN RETURN["(Time)"]

ELSE RETURN[ Rope.Cat["(", GetName[type], ")"] ] };

CycleNewOld: Buttons.ButtonProc = TRUSTED

{ viewer: ViewerClasses.Viewer = NARROW[ parent, ViewerClasses.Viewer ];

Labels: ARRAY[0..3) OF ROPE = ["", "N", "O"];

attrViewer: VTable = viewer.parent;

relRow: VTable = attrViewer.parent;

TuplesTable: VTable = relRow.parent;

EventTable: VTable = TuplesTable.parent;

attr: Attribute = V2E[ ViewerOps.FetchProp[ attrViewer, $attr ] ];

which: REF INT = NARROW[ViewerOps.FetchProp[attrViewer, $which], REF INT];

IF NOT NutOps.EntityValued[attr] THEN RETURN;

which^ ← (which^ + 1) MOD 3;

Buttons.ReLabel[viewer, Labels[which^] ];

ViewerOps.AddProp[attrViewer, $which, which ];

Install[ relRow, FALSE ];

Install[ TuplesTable, FALSE ];

Install[ EventTable, TRUE ] };

SaveTuples: PUBLIC ENTRY PROC[viewer: VTable, newEntity: Entity ← NIL ] RETURNS [errors: BOOL] =

Called to update the relationships for an entity. If newEntity is NIL, then destroy

all the relationships for the oldEntity (previously associated with $Entity property

of the viewer). If oldEntity was NIL, then create a new entity with the relationships

that have been filled in by the user. If newEntity=oldEntity, update the relationships

that were modified by the user. Finally, if NIL#newEntity#oldEntity#NIL, then

copy all of oldEntities relationships to reference newEntity (leaves oldEntity intact).

Returns TRUE if any errors were reported to the user as a result of bad entries.

{ ENABLE UNWIND => NULL;

tupleRows: CARDINAL = GetRowsAndColumns[ viewer ].rows;

oldEntity: DB.Entity = V2E[ViewerOps.FetchProp[viewer, $Entity]];

update: BOOLEAN = NOT DB.Null[oldEntity] AND DB.Eq[oldEntity, newEntity];

destroy: BOOLEAN = NOT DB.Null[oldEntity] AND newEntity = NIL;

create: BOOLEAN = NOT DB.Null[newEntity] AND oldEntity = NIL;

copy: BOOLEAN = NOT (destroy OR create OR update);

parent: Viewer = viewer.parent;

anyErrors← FALSE;

FOR i: CARDINAL IN [0..tupleRows-1) DO

j: CARDINAL ← 0;

relTable ← GetTableEntry[ table: viewer, row: i, column: 0 ];

relRows ← GetRowsAndColumns[ relTable ].rows;

WHILE j < relRows-1 DO

The relRows is the number of rows with relationships from relation rel; for each

tuple (maybe >1 row), we want to destroy, create, or update the relationship as specified.

relViewer: Viewer = GetTableEntry[relTable, j, 0];

rel: Relation = V2E[ViewerOps.FetchProp[relViewer, $r ] ];

attr: Attribute = V2E[ViewerOps.FetchProp[ relViewer, $a ] ];

oldRelship← V2E[ViewerOps.FetchProp[relViewer, $relShip ] ];

updateList← NIL; allFieldsNull← TRUE; newRelship← NIL;

Advance j through attributes of this tuple, AddFields picking off two at a time, to

see what the attributes are and which we might have to change.

AddFields[ parent: parent, row: j, copy: NOT (destroy OR create OR update) ];

NOTE: AddFields modifies global updateList and allFieldsNull as side effect

IF PastLastRowOfTuple[j← j + 1, relRows, relTable] THEN EXIT;

ENDLOOP;

Now we want to either create, destroy, or update the relationship.

IF destroy THEN

Destroy this relationship. We've already advanced j to skip over its rows.

{IF NOT DB.Null[oldRelship] THEN DB.DestroyRelship[oldRelship]}

ELSE IF updateList#NIL THEN -- Continue only if user modified something in this tuple..

IF update AND NOT DB.Null[oldRelship] THEN

Update mode, and there was an existing relationship: modify or delete it.

IF allFieldsNull THEN DB.DestroyRelship[oldRelship]

ELSE UpdateTuple[oldRelship, updateList]

ELSE IF NOT allFieldsNull THEN

Either we are adding relship to a new entity, or updating old entity with no existing

oldRelship: create new tuple, including first attr (that refs entity) in update list.

{ updateList ← CONS[ AttributeValue[ attribute: attr, lo: newEntity], updateList ];

UpdateTuple[CreateRelship[rel], updateList];

ViewerOps.AddProp[ relViewer, $relShip, newRelship ] };

ENDLOOP;

RETURN[anyErrors]

};

PastLastRowOfTuple: PROC[j: CARDINAL, relRows: CARDINAL, relTable: VTable ] RETURNS [BOOL] =

Used only by SaveTuples above, to decide when cross tuple boundaries in VTable.

Returns TRUE if j has passed the last row in one of the tuples for the given relation relTable.

Since $newLine is only attached to the relation button, this is true iff $newLine

is attached to this entry, or j is greater than the last row in the relTable.

{ RETURN[ j >= relRows-1 OR

NARROW[ViewerOps.FetchProp[GetTableEntry[relTable, j, 0], $newLine], REF BOOL]^]};

UpdateTuple: PROC[ t: Relship, updateList: AttributeValueList ] =

Changes the Relship t as specified by updateList. If ALL of the values in the update list

are NILs, then just destroy the whole Relship, 'cause user has left all blanks.

{

First set all of the key values

FOR ul: AttributeValueList ← updateList, ul.rest UNTIL ul = NIL DO

av: AttributeValue = ul.first;

u: Uniqueness = V2U[GetP[av.attribute, aUniquenessIs]];

IF u = Key THEN SetF[ t, av.attribute, av.lo ]

ENDLOOP;

Now set all of the non-key attributes

FOR ul: AttributeValueList ← updateList, ul.rest UNTIL ul = NIL DO

av: AttributeValue = ul.first;

u: Uniqueness = V2U[GetP[av.attribute, aUniquenessIs]];

IF u # Key THEN SetF[ t, av.attribute, av.lo ]

ENDLOOP };

PropertyValueList: TYPE = LIST OF PropertyValue;

PropertyValue: TYPE = RECORD[

from: Attribute, -- entity-valued attribute of a relation

avl: AttributeValueList -- value contraints on other attributes of same relation

];

QueryTuples: PUBLIC ENTRY PROC[ viewer: VTable, domain: Domain ]

RETURNS [el: LIST OF Entity] =

Given a table set up by DisplayTuples, finds all the entities in the given domain

that satisfy the query filled into the table by the user. Inner loop similar to SaveTuples,

but must create PropertyValueList instead of updating tuples.

{ ENABLE UNWIND => NULL;

tupleRows: CARDINAL = GetRowsAndColumns[ viewer ].rows;

queryList: PropertyValueList← NIL;

parent: Viewer = viewer.parent;

FOR i: CARDINAL IN [0..tupleRows-1) DO

j: CARDINAL ← 0;

relTable ← GetTableEntry[ table: viewer, row: i, column: 0 ];

relRows ← GetRowsAndColumns[ relTable ].rows;

WHILE j < relRows-1 DO

The relRows is the number of rows with relationships from relation rel; for each

tuple (maybe >1 row), we want to handle the relationship as specified.

relViewer: Viewer = GetTableEntry[relTable, j, 0];

rel: Relation = V2E[ViewerOps.FetchProp[relViewer, $r ] ];

attr: Attribute = V2E[ViewerOps.FetchProp[ relViewer, $a ] ];

updateList← NIL; allFieldsNull← TRUE;

Advance j through attributes of this tuple, AddFields picking off two at a time, to

see what the attributes are and which we might have to change.

AddFields[ parent: parent, row: j, copy: FALSE ];

NOTE: AddFields modifies global updateList and allFieldsNull as side effect

IF PastLastRowOfTuple[j← j + 1, relRows, relTable] THEN EXIT;

ENDLOOP;

IF updateList#NIL AND NOT allFieldsNull THEN

Continue only if user modified and put something in this tuple..

queryList← CONS[[from: attr, avl: updateList], queryList];

ENDLOOP; -- WHILE j < relRows-1

ENDLOOP; -- FOR i: CARDINAL

RETURN[EntityQuery[queryList]];

};

EntityQuery: PROC[pvl: PropertyValueList] RETURNS[LIST OF Entity] =

A handy procedure for finding all the entities of a domain that have the given

property values. Finds all the entities which, for each PropertyValue in the

PropertyValueList list, there exists at least one relationship whose

"from" attribute equals the entity and whose other attributes satisfy the

attribute value list.

{ f: Attribute← pvl.first.from;

r: Relation← V2E[GetP[f, aRelationIs]];

elNew: LIST OF Entity← NIL;

nestedRS: RelshipSet← RelationSubset[r, pvl.first.avl];

FOR t: Relship← NextRelship[nestedRS], NextRelship[nestedRS] UNTIL t=NIL DO

elNew← CONS[V2E[GetF[t, f]], elNew] ENDLOOP;

ReleaseRelshipSet[nestedRS];

RETURN[NestedEntityQuery[elNew, pvl.rest]]

};

NestedEntityQuery: PROC[elOld: LIST OF Entity, pvl: PropertyValueList]

RETURNS[LIST OF Entity] =

Finds the entities in elOld that satisfy pvl. We do this recursively as follows.

For each entity in elOld, we do a RelationSubset to find the tuples that satisfy pvl.first

and also reference the entity. If this list is not empty, we can keep that entity in a

new list elNew; otherwise we toss it. When all the entities in elOld that also

satisfy pvl.first have been added to elNew in this way, we recursively call

NestedEntityQuery, returning the entities in elNew which also satisfy pvl.rest.

{ IF pvl=NIL THEN RETURN[elOld] ELSE

{ f: Attribute← pvl.first.from;

r: Relation← V2E[GetP[f, aRelationIs]];

elNew, elEnd: LIST OF Entity← NIL; -- will equal those in elOld that satisfy pvl.first

FOR elOldT: LIST OF Entity← elOld, elOldT.rest UNTIL elOldT=NIL DO

nestedRS: RelshipSet← RelationSubset[r, CONS[ [f, elOldT.first], pvl.first.avl]];

The nestedRS contains tuples that reference e and also satisfy first element of pvl.

We can keep elOldT.first in the elNew list iff this list is non-empty.

IF NextRelship[nestedRS] #NIL THEN

IF elNew=NIL THEN elEnd← elNew← CONS[elOldT.first, NIL]

ELSE elEnd← elEnd.rest← CONS[elOldT.first, NIL];

ReleaseRelshipSet[nestedRS];

ENDLOOP;

RETURN[NestedEntityQuery[elNew, pvl.rest]];

}};

AddFields: PROC[parent: Viewer, row: CARDINAL, copy: BOOL] =

NOTE THIS PROCEDURE UPDATES GLOBAL VARIABLES AS A SIDE EFFECT.

THE MONITOR ON THIS MODULE IS TO PROTECT THESE GLOBAL VARIABLES.

Adds to updateList the attributes in row that need to be assigned in order to create

the relationship. Caller must add the first attribute (that refs the entity),

if desired. If the user does not modify a field, it does not appear in the updateList

unless there was an existing relationship and we are in "copy" mode.

Thus updateList=NIL if the user modified no fields of a tuple. Sets allFieldsNull to

FALSE if any of the fields are non-null.

{

FOR i: INT IN [0..2) DO

attrViewer: VTable = GetTableEntry[relTable, row, i+1];

IF attrViewer # NIL THEN

{ attr: Attribute = V2E[ViewerOps.FetchProp[attrViewer, $attr]];

newOld: INT = NARROW[ViewerOps.FetchProp[attrViewer, $which], REF INT]^;

textViewer: Viewer = GetTableEntry[table: attrViewer, column: 3];

contents: ROPE = ViewerTools.GetContents[textViewer];

type: Entity = V2E[GetP[attr, aTypeIs, aTypeOf]];

value: DB.Value;

IF NOT textViewer.newVersion THEN

Skip this guy unless copying and there was an existing relationship

IF oldRelship=NIL OR NOT copy THEN LOOP;

IF NOT Rope.Equal[contents, ""] THEN allFieldsNull← FALSE;

SELECT type FROM

IntType => {

val: INT = IF Rope.Equal[contents, ""] THEN 0 ELSE IO.GetInt[ IO.RIS[contents] ];

value ← I2V[val]};

RopeType =>

value ← S2V[ contents ];

BoolType =>

value ← B2V[ Rope.Equal[contents, "TRUE"] ];

TimeType =>

{ time: DB.GMT;

time.time ← IO.GetTime[IO.RIS[contents] ! IO.Error => TRUSTED {

anyErrors← TRUE;

NutViewer.Error[parent, "Unintelligible time/date: ", contents]}];

value ← T2V[time] };

ENDCASE =>

IF Rope.Equal[contents, ""] THEN value← NIL

ELSE SELECT newOld FROM

0 => -- NewOrOld

{ value ← DeclareEntity[ d: type, name: contents, version: OldOnly ];

IF value = NIL THEN {

NutViewer.Message[parent, "Automatically creating ", contents];

value ← DeclareEntity[ d: type, name: contents ];

IF value = NIL THEN {

allFieldsNull← TRUE; -- pretend this tuple didn't happen

anyErrors← TRUE;

NutViewer.Error[parent, " Error: ", contents, " could not be created automatically."]; } } };

1 => -- NewOnly

{ value ← CreateEntity[ d: type, name: contents !

DBEnvironment.Error => TRUSTED {

codeRef: REF DBEnvironment.ErrorCode ~ NEW[DBEnvironment.ErrorCode ← code];

NutViewer.Error[parent, IO.PutFR["%g", IO.refAny[codeRef]], " Error trying to create \"", contents, "\" entity."];

allFieldsNull← TRUE; -- pretend this tuple didn't happen

anyErrors← TRUE;

CONTINUE}]};

2 => -- OldOnly

{ value ← DeclareEntity[ type, contents, Version[OldOnly] ];

IF value = NIL THEN {

allFieldsNull← TRUE; -- pretend this tuple didn't happen

anyErrors← TRUE;

NutViewer.Error[parent, " Error: ", contents, " does not exist."] }};

ENDCASE;

updateList ← CONS[ AttributeValue[attribute: attr, lo: value], updateList ] }

ENDLOOP

};

Change Log:

Changed by Cattell April 6, 1983 1:12 pm: The CONS in AddRow's first loop was causing it to reverse the order of the attributes to be displayed from the order in the database. Changed loop to destructively modify list, more efficient anyway since no space allocation.

Changed by Cattell April 15, 1983 11:08 am: Numerous changes and bug fixes to SaveTuples. Reduced complexity of inner loop from 22 to 11 lines!

Edited on March 21, 1984 9:17:51 pm PST, by Beach

added Cedar formatting via TiogaMesa.

changes to: AddFields to detect errors more often when creating entities automatically.

Edited on March 28, 1984 9:25:52 pm PST, by Beach

cosmetic changes to the {} conventions and indentation.

changes to: RelProc to preserve the newVersion status when expanding a relation row with the blue button.